OA17469A - Upgrading process streams. - Google Patents
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- OA17469A OA17469A OA1201500348 OA17469A OA 17469 A OA17469 A OA 17469A OA 1201500348 OA1201500348 OA 1201500348 OA 17469 A OA17469 A OA 17469A
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Abstract
Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful intermediates and products, such as energy, fuels, foods or materials. Systems, methods and equipment are described for upgrading process streams using electrodialysis or electrodialysis reversal. Many potential lignocellulosic feedstocks are available today, including agricultural residues, woody biomass, municipal waste, oilseeds/cakes and seaweed, to name a few.
Description
[0001] This application claims priority from the following provisional applications: USSN 61/774,684, filed March 8, 2013; USSN 61/774,773, filed March 8, 2013; USSN 61/774,731, filed March 8, 2013; USSN 61/774,735, filed March 8, 2013; USSN 61/774,740, filed March 8, 2013; USSN 61/774,744, filed March 8, 2013; USSN 61/774,746, filed March 8, 2013; USSN 61/774,750, filed March 8, 2013; USSN 61/774,752, filed March 8, 2013; USSN 61/774,754, filed March 8, 2013; USSN 61/774,775, filed March 8, 2013; USSN 61/774,780, filed March 8, 2013; USSN 61/774,761, filed March 8, 2013; USSN 61/774,723, filed March 8, 2013; and USSN 61/793,336, filed March 15,2013. The full disclosure of each of these provisional applications is incorporated by reference herein.
BACKGROUND OF THE INVENTION [0002] Many potential lignocellulosic feedstocks are available today, including agricultural residues, woody biomass, municipal waste, oilseeds/cakes and seaweed, to name a few. At présent, these materials are often under-utilized, being used, for example, as animal feed, biocompost materials, bumed in a co-generation facility or even landfilled.
[0003] Lignocellulosic biomass includes crystalline cellulose fibrils embedded in a hemicellulose matrix, surrounded by lignin. This produces a compact matrix that is difficult to access by enzymes and other chemical, biochemical and/or biological processes. Cellulosic biomass materials (e.g., biomass material from which the lignin has been removed) is more accessible to enzymes and other conversion processes, but even so, naturally-occurring cellulosic materials often hâve low yields (relative to theoretical yields) when contacted with hydrolyzing enzymes. Lignocellulosic biomass is even more récalcitrant to enzyme attack. Furthermore, each type of lignocellulosic biomass has its own spécifie composition of cellulose, hemicellulose and lignin.
SUMMARY [0004] Generally, the methods and equipment used for producing useful products from a biomass material are described herein. Generally, many methods include treating a récalcitrant biomass, e. g. treating with électron beams, and then biochemically and/or chemically processing the reduced recalcitrance material to a mixture of sugars, for example, glucose, xylose, arabinose, fructose, sugar alcohols, e. g. xylitol and other products. Salts (e.g., ions) generated during processing of the feedstock can be removed via the process of electrodialysis, e. g. common or standard electrodialysis (ED), electrodialysis reversai (EDR) and/or bipolar membrane electrodialysis (EDBM). The method of electrodialysis can help in removing the bulk salts from the sugar solution, or electrodialysis can be used to separate the organic acids from other compounds in a mixture. Prior to and/or after electrodialysis the biomass liquids can be also treated to remove other impurities and color.
[0005] In one aspect the invention features methods for removing and/or separating salts, partially ionized acids or fully ionized acids, from saccharified biomass liquids, such as including sugars and/or fermented liquids utilizing an electrodialysis system. The methods can therefor provide a processed solution (e.g., purified solution, upgraded process steam, purified process stream). Optionally, the electrodialysis system utilizes standard electrodialysis or electrodialysis reversai. Also optionally, the saccharified biomass liquids includes a reduced recalcitrance cellulosic or lignocellulosic material that has been saccharified. For example, saccharification can be done by utilizing one or more enzymes and/or one or more acids, such as sulfuric acid. For example, saccharification can be done by using an enzyme, using an acid, using an acid and then an enzyme, using an enzyme and then an acid or using an enzyme and an acid concurrently. Optionally, the cellulosic or lignocellulosic material has had its recalcitrance reduced by treatment with ionizing radiation (e.g., with between about 10 and about 50 Mrad of radiation). For example, the ionizing radiation can be in the form of accelerated électrons.
[0006] In another embodiment the saccharified product is fermented and then electrodialysis is applied with or without purification. In this embodiment fermentation broth can often include a product from converting one of the sugars to spécifie product and another sugar that remains unconverted during the fermentation. The fermentation broth can be subject to electrodialysis to remove salts that it been formed. Then the product can be isolated by using a bipolar electrodialysis operation.
[0007] In some implémentation, while utilizing the electrodialysis system, a voltage of between about 10 and 600V across ion sélective membranes can be applied while flowing the saccharified biomass liquids and/or the fermentation product liquids past the membranes. Optionally, the voltage can be between 25 and 500 V. Additionally, the voltage can be 40 to 450 V. These voltages can be across multiple membranes.
[0008] In some implémentations, the saccharified biomass liquids can be further processed with a fermentation step to produce fermentation products, such as an alcohol, organic acids. Optionally, the saccharified biomass liquids are liquids wherein a fermentation product (e.g., an alcohol such as éthanol, propanol or butanol or an organic acid such as acetic acid, propionic acid, succinic acid, tartane acid, butyric acid and lactic acid) has been removed therefrom by electrodialysis or other isolation means (e.g., by distillation).
[0009] In some implémentations, the ionic strength of the saccharified liquid prior to electrodialysis is between about 500 and about 50,000 pS/cm (microSiemens/cm), and wherein an ionic strength of the saccharified biomass liquids after utilizing the electrodialysis system (e.g., the processed solution, purified solution, upgraded process steam or purified process stream) is between 1 and 100 pS/cm. Optionally the salts, partially ionized acids or fully ionized acids removed during electrodialysis include at least one element selected from P, K, Mg, Na, Ca, S, Mn, Al, Zn, Si, Cl and Fe. For example, the ions can be phosphates, sulfates, chlorides, silicates, aluminates, K+, Na+, Mg2+, Al3+, Zn2+, Mn2+, Fe3+, Fe2+, and mixtures of these ions.
[0010] Alternatively or additionally, the saccharified biomass liquids include saccharification residues (e.g., cells, proteinaceous, lignin derived material and/or colored bodies). In a similar manner the saccharified biomass is fermented to obtain a fermentation product stream which had fermentation residues (e.g., cells, proteinaceous, lignin derived material and/or colored bodies). In some implémentations, the method can further include purifying the saccharified biomass liquids or fermentation product stream before, during and/or after utilizing the electrodialysis system. For example, purifying by a method selected from any one of the following methods: chromatography, filtration, centrifugation, précipitation, distillation, complexation and combinations thereof. When précipitation is utilized in purifying, one or more solvents or non-solvents (e.g., methanol, éthanol, isopropanol, acetone, ethyl ether and tetrahydrofuran, and mixtures of these) can be used to precipitate one or more undesired components, such as an impurity. Some implémentations include decolorizing the saccharified biomass liquids or fermentation product streams with a decolorizing agent before, during and/or after
utilizing the electrodialysis System. For example, decolorizing utilizing any one of powdered carbon, granular carbon, extruded carbon, bone char carbon, bead activated carbon, styrenic resins, acrylic resins, magnetic resins, decolorizing clays, bentonite, attapulgite, montmorillonite, hormite and combinations of these. For example mixing the saccharified biomass liquids or fermentation product stream and filtering away the solids, or flowing (e.g., filtering) the saccharified biomass liquids these solids. The solution after decolorization can be less than about 100 color units (e.g., less than 50, less than about 40, less than about 30, less than about 20, less than about 10, less than about 5 and even less than about 1).
[0011] In some implémentations, the saccharified biomass liquids include one or more saccharides, e.g., a monodisaccharide, an oligosaccharides and/or a polysaccharide. Optionally the saccharified biomass liquids include a sugar selected from xylose, glucose, arabinose, fructose and mixtures of these. Optionally, the sugar is xylose and the purity of the processed solution (e.g., purified solution, upgraded process steam, purified process stream) after utilizing the electrodialysis system is at least about 80 wt.% xylose (e.g., the wt.% of the xylose to the total solids/dissolved solids in solution as determined analytically by HPLC). For example, after electrodialysis the xylose purity is at least 85 wt.%, at least 90 wt.%, at least 95 wt.%, at least 96 wt.%, at least 97 wt.% or even at least 98 wt.%). Optionally, the sugar includes arabinose, and the purity of the solution after utilizing the electrodialysis system is about 0.5 wt.% arabinose (e.g., about 1 to 0 wt.%, about 1 to 0.1 wt.%, about 0.8 to 0.1 wt.%, about 0.8 to 0.2 wt.%, about 0.5 to 1.0 wt.%, about 0.1 to 0.5 wt.%).
[0012] These saccharified biomass liquids with sugars présent can be fermented to produce additional biomass liquids. Examples of the fermentation include adding microorganisms that selectively convert one sugar in preference to another. For instance, in a saccharified biomass liquid with glucose and xylose présent a microorganism can be chosen which can selectively convert glucose to éthanol while leaving the xylose basically unreacted. In a similar manner glucose can be selectively converted to D- or Llactic acid.
[0013] Removing the ions (e.g., salts, fully or partially dissociated acids) from the sugar solutions derived from cellulosic and lignocellulosic biomass liquids is advantageous because it increases the purity of the processed solution (e.g., purified solution, upgraded process steam, purified process stream) and assists in subséquent séparation of the various product steams such as sugars. This ultimately can aid in further transformations of these process streams into high value produces such as sugars, sugar
alcohols (e.g., xylose, arabinose, xylitol and sorbitol). For example, it can be easier to crystalize sugars and other products without salts présent. Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
[0014] Implémentations of the embodiments can optionally include one or more of the following summarized features. In some implémentations, the selected features can be applied or utilized in any order while in other implémentations a spécifie selected sequence is applied or utilized. Individual features can be applied or utilized more than once in any sequence and even continuously. In addition, an entire sequence, or a portion of a sequence, of applied or utilized features can be applied or utilized once, repeatedly or continuously in any order. In some optional implémentations, the features can be applied or utilized with different, or where applicable, the same set or varied, quantitative or qualitative parameters as determined by a person skilled in the art. For example, parameters of the features such as size, individual dimensions (e.g., length, width, height), location of, degree (e.g., to what extent such as the degree of recalcitrance), duration, frequency of use, density, concentration, intensity and speed can be varied or set, where applicable, as determined by a person of skill in the art.
[0015] Features, for example, include: a method for removing salts, partially ionized acids or fully ionized acids, from saccharified biomass liquids utilizing an electrodialysis system; a method that utilizes electrodialysis; electrodialysis reversai; a method that utilizes bipolar membrane electrodialysis treating a liquid, where the liquid includes a reduced recalcitrance, cellulosic or lignocellulosic material that has been saccharified; treating a liquid, where the liquid includes a cellulosic or lignocellulosic material that has had its recalcitrance reduced by treatment with ionizing radiation; treating a liquid, where the liquid includes a cellulosic or lignocellulosic material that has had its recalcitrance reduced by treatment with accelerated électrons; treating a liquid, where the liquid includes a cellulosic or lignocellulosic material that has been saccharified utilizing one or more enzymes; treating a liquid, where the liquid includes a cellulosic or lignocellulosic material that has been saccharified utilizing one or more acids; treating a liquid, where the liquid includes a cellulosic or lignocellulosic material that has been saccharified utilizing sulfuric acid; an ionic strength of the saccharified biomass liquids prior to electrodialysis is between about 500 and about 50,000 pS/cm, and an ionic strength of the saccharified biomass liquids after electrodialysis is between 1 and 100 pS/cm; salts, partially ionized acids or fully ionized acids that include the element phosphorous are removed utilizing an electrodialysis system; salts, partially ionized acids
or fully ionized acids that include the element potassium are removed utilizing an electrodialysis System; salts, partially ionized acids or fully ionized acids that include the element magnésium are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element sodium are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids including the element calcium are removed utilizing an electrodialysis System; salts, partially ionized acids or fully ionized acids that include the element S are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element oxygen are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element manganèse are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element aluminum are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element zinc are removed utilizing an electrodialysis System; salts, partially ionized acids or fully ionized acids that include the element silicon are removed utilizing an electrodialysis system; salts, partially ionized acids or fully ionized acids that include the element chloride are removed utilizing an electrodialysis System; salts, partially ionized acids or fully ionized acids that include the element Fe are removed utilizing an electrodialysis system; purifying a saccharified biomass liquids utilizing chromatography; purifying a saccharified biomass liquids utilizing filtration; purifying a saccharified biomass liquids utilizing centrifugation; purifying a saccharified biomass liquids utilizing précipitation; purifying a saccharified biomass liquids utilizing distillation; purifying a saccharified biomass liquids utilizing complexation; purifying a saccharified biomass liquids by the addition of one or more solvents or non-solvents to precipitate one or more undesired components; purifying a saccharified biomass liquids by the addition of methanol to precipitate one or more undesired component; purifying a saccharified biomass liquids by the addition of éthanol to precipitate one or more undesired components; purifying a saccharified biomass liquids by the addition of isopropanol to precipitate one or more undesired components; purifying a saccharified biomass liquids by the addition of acetone to precipitate one or more undesired components; purifying a saccharified biomass liquids by the addition of ethyl ether to precipitate one or more undesired components; purifying a saccharified biomass liquids by the addition of tetrahydrofuran to precipitate one or more undesired components; treating a saccharified biomass liquids that includes one or more fermentation products; treating a saccharified biomass liquids that includes liquids that hâve had a fermentation product and the fermentation product
has been distilled therefrom; treating a saccharified biomass liquids that includes liquids that hâve had an alcohol fermentation product and the alcohol has been distilled therefrom; treating a saccharified biomass liquids that includes liquids that hâve had an éthanol fermentation product and the éthanol has been distilled therefrom; decolorizing a 5 saccharified biomass liquids utilizing a decolorizing agent; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including powdered carbon; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including granular carbon; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including extruded carbon; decolorizing a saccharified biomass liquids utilizing a decolorizing 10 agent including bone char carbon; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including bead activated carbon; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including styrenic resins; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including acrylic resins; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including magnetic resins; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including decolorizing clays; a method that includes decolorizing a saccharified biomass liquids utilizing a decolorizing agent including bentonite; a method that includes decolorizing a saccharified biomass liquids utilizing a decolorizing agent including attapulgite; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including montmorillonite; decolorizing a saccharified biomass liquids utilizing a decolorizing agent including hormite; decolorizing a saccharified biomass liquids utilizing a decolorizing agent and after decolorizing the color of the solution is less than about 100 color units; decolorizing a saccharified biomass liquids utilizing a decolorizing agent and after decolorizing the color of the solution is less than about 10 color units;
decolorizing a saccharified biomass liquids utilizing a decolorizing agent and after decolorizing the color of the solution is less than about 5 color units; treating a saccharified biomass liquid utilizing a electrodialysis System and applying a voltage of between about 10 and 600V across ion sélective membranes of the electrodialysis System while flowing the saccharified biomass liquids past the membranes; treating a saccharified biomass liquids that includes one or more saccharides; treating a saccharified biomass liquids that includes xylose; treating a saccharified biomass liquids that includes glucose; treating a saccharified biomass liquids that includes arabinose; treating a saccharified biomass liquids that includes fructose; purifying a saccharified liquids utilizing an electrodialysis System, wherein the liquids includes xylose and the qc purity of the xylose after utilizing the electrodialysis System is at least about 80 wt.%;
purifying a saccharified liquids utilizing an electrodialysis system, wherein the liquids includes arabinose and the purity of the arabinose after utilizing the electrodialysis System is at least about 0 to 1 wt.%.
[0016] Altemately, the saccharified biomass may be fermented and then electrodialysis steps applied. An initial electrodialysis step can remove salts especially inorganic salts, followed by a second electrodialysis step using a bipolar electrolysis step to isolate valuable ionizable organic products from the fermentation system. Subséquent purification steps as described above may be used for further purify the ionizable organic products.
[0017] Other features and advantages of the invention will be apparent from the following detailed description, and from the claims.
DESCRIPTION OF DRAWINGS [0018] FIG. IA is a diagram showing an electrodialysis process.
[0019] FIG. IB is a diagrammatic view of an exemplary electrodialysis system.
[0020] FIG. 2 is a flow chart showing the steps of purifying (treating) the biomass before subjecting it to electrodialysis.
[0021] FIG. 3 is a plot showing conductivity vs time during an electrodialysis process.
[0022] FIG. 4 is flow chart showing the steps of purifying an ionizable organic product after a fermentation step; specifically D- or L-lactic acid.
[0023] FIG. 5 is a flow chart showing steps for using two electrodialysis steps for isolating an organic acid.
DETAILED DESCRIPTION [0024] Using the methods and Systems described herein, cellulosic and lignocellulosic feedstock materials, for example that can be sourced from biomass (e.g., plant biomass, animal biomass, paper, and municipal waste biomass) and that are often readily available but difficult to process, can be converted to solutions containing sugars such as xylose and glucose, which can in some cases be further processed to produce other useful products (e.g., alcohols such as éthanol and butanol and organic acids such as acetic acid, propionic acid, succinic acid, tartaric acid, butyric acid and lactic acid). Methods and Systems are discussed herein for removing unwanted components, such as salts (e.g. ions), and acids (e.g., organic acids) from these biomass liquids by conventional electrodialysis, electrodialysis reversai and/or bipolar membrane electrodialysis.
[0025] Processes for manufacturing sugar solutions and products derived therefrom are described herein. These processes may include, for example, optionally mechanically treating a cellulosic and/or lignocellulosic feedstock. Before and/or after this treatment, the feedstock can be treated with another treatment, for example, irradiation, steam explosion, pyrolysis, sonication, chemical treatment (e.g., with and acid or a base) and/or oxidation to reduce, or further reduce its recalcitrance.
[0026] A solution rich in sugar can be produced by saccharifying the treated and irradiated feedstock by the addition of one or more enzymes. Many other products or biomass liquids may be derived from the sugar solution, for example, by fermentation to an alcohol such as éthanol, organic acids such as lactic acid or by réduction to a sugar alcohol such as xylitol, sorbitol etc. The solution also includes several unwanted ions, the bulk of which can be removed by electrodialysis. Before or after electrodialysis, the saccharification or fermentation product can be further purified.
[0027] Electrodialysis is a membrane séparation process wherein the membrane is permeable to small species (e.g., ions) but not to larger species (e.g., molécules such as sugars). Electrodialysis differs from pressure driven membrane processes by utilizing electrical potential as the main driving force in matter séparation making it useful for charged particles, for example, ions. Since the charged particles are mobile, the séparation media transfers the electric current with relatively low résistance, electrodialysis is generally carried out in aqueous solutions. In the electrodialysis process, the liquid is made to flow through a séparation cell (e.g., an area, a tube or chamber) enclosed by cation and anion sélective membranes. In addition, while flowing the process liquid through the séparation cell, the process liquid is subjected to an electrical potential using positively and negatively charged électrodes. The séparation cell is generally configured so that the cations can migrate through the cation sélective membrane towards the negatively polarized electrode, and the anions migrate through the anion sélective membrane towards the positively charged electrode. The arrangement of the cell ensures that ions are concentrated outside of the cell, and can be flowed away, while the ion depleted fluids can be collected. The process fluid can be circulated through the process cell repeatedly, for example, until a solution with the desired concentration of ions is be obtained. Multiple séparation cells can be used in sériés or in parallel to achieve the optimum process results.
[0028] A subset of electrodialysis is using bipolar membranes to separate materials. Bipolar membranes consist of an anion-permeable membrane and a cation permeable membrane laminated together. When this composite structure is oriented such that the cation-exchange layer faces the anode it is possible, by imposing a potential field across the membrane, to spit water into proton and hydroxyl ions. This results in the production of acidic and basic solutions at the surfaces of the bipolar membranes. Multiple bipolar membranes along with other ion permeable membranes can be placed between a single pair of électrodes in an electrodialysis stack for the production of acid and base from a neutral sait. For example, this strategy - - bipolar membrane electrodialysis may be used to isolate lactic acid or another organic acid from a fermentation product mixture. The lactic acid or other organic acids may be converted to its sait form processed through conventional electrodialysis followed by processing with bipolar membrane electrodialysis to produce purified lactic acid (and/or organic acids) in its acid form.
[0029] FIG. IA is a diagram showing how electrodialysis opérâtes on a feed stream (e.g., contaîning sugars and salts). Feed stream 10 and makeup water 20 (brine makeup) enter the system. A potential 30 (DC voltage) is applied to the feed and makeup water which are separated by an ion sélective membrane. The potential drives the ions preferentially into the makeup water. A demineralized product 40 exits the system, where the ions hâve been reduced as compared to the feed process stream. The ions that hâve been removed from the feed are brought out of the System as the brine blowdown
50. The process can be repeated, e.g. feeding the demineralized product back into the electrodialysis system to further remove ions (e.g., transfer them to brine blowdown). The process can be repeated until the desired réduction in ions is achieved, as will be further described below.
[0030] One possible arrangement of a membrane configuration in an electrodialysis system that can be utilized to purify saccharified lignocellulosic material is shown by FIG IB. This system utilizes alternating cation sélective membranes 2101 and anion sélective membranes 2102. Spacers (not shown) are placed between eveiy membrane to ensure there is room between membranes for the process liquids to flow. The électrodes, 2103 and 2104, are not in physical contact with the process fluid but rather are in physical contact with a spécial conductive solution (electrolyte). The conductive solution serves the purpose of keeping unwanted reactions from occuning at the electrode. For example, a sulfuric solution splits water into hydrogen gas at the cathode and oxygen gas at the anode, both of which can be removed without damaging the électrodes or other
components. The électrodes are therefore in electrical contact with the process fluids through the electrolyte.
[0031] Therefore, the arrangement as described above créâtes a sériés of flow channels (2105 and 2106) through which the process fluid (e.g., the sugar solution produced from a saccharified lignocellulosic material) is made to flow (e.g., by the action of a pump) while an electrical potential is applied to the flowing solution. Under operation, for example, the cations in every second flow channel 2105 flow towards the cathode 2103 and are able to migrate through the adjacent cation sélective membrane 2101 into the next flow channel 2106. The cations are then trapped in flow channels 2105, unable to migrate through the anion sélective membranes 2102. Conversely, the anions in the flow channels 2105 are able to migrate towards the anode 2104 through the anion sélective membranes 2102 and into alternating flow channels 2106 where they are trapped, unable to migrate further, since they encounter the cation sélective membranes 2101. In this arrangement, the cations and anions migrate out of every second flow channel 2105, such that the process fluid in the flow channels 2105 ends up substantially free of ions, while the process fluid in the remaining channels 2106 contains a high concentration of both cations and anions. The resuit is that by collecting the outlet of the flow channels 2105 and 2106 separately, a depleted-ion sugar solution (from flow channels 2105) and a separate enriched-ion sugar solution (from flow channels 2106) are obtained. Increasing the number of ion exchange membranes and flow channels greatly improves the efficiency of the System. For example, 10, 20, 50, 100 or even more membranes can be used.
[0032] In addition to sugars and products such as alcohols, the solutions derived from biomass by the processes such as saccharification and fermentation (described herein) can include various materials, for example, suspended or dissolved compounds and/or materials. For example, solutions can include enzymes (e.g., parts of enzymes, active enzymes, denatured enzymes), amino acids, nutrients, live cells, dead cells, cellular débris (e.g., lysed cells, yeast extract), acids, bases, salts (e.g., halides, sulfates, and phosphates, alkali, alkali earth, transition métal salts), partial hydrolysis products (e.g., cellulose and hemicellulose fragments), lignin, lignin residues, inorganic solids (e.g., siliceous materials, clays, carbon black, metals), remnants of saccharified and/or fermented biomass, and combinations thereof. The sugar solution may undergo purification processes, which may include a simulated bed chromatography, rotary drum filtration, filtration and or decolorization prior to being subjected to electrodialysis.
Optionally, these impurities can be removed or reduced (e.g., decreased m concentration)
prior to subjecting the biomass solution to electrodialysis. In particular, it may be bénéficiai to remove impurities (e.g., polymers, proteins, précipitants) that can coat, plug, fill or otherwise hinder the function of the electrodialysis membranes. In general, electrodialysis is subject to membrane fouling from particles and organic materials, for example, the organic impurities that can lead to color as previously discussed. Therefore, electrodialysis is preferably done after removing these materials. If fouling does occur, the membranes can be regenerated running the process in reverse by reversing the direction of constant current driving the séparation and switching the dilution and concentration chambers.
[0033] A possible process for purifying biomass liquids, e. g. product liquids from saccharified feedstock or fermentation liquids before introducing it to electrodialysis, to avoid this fouling, is shown in FIG. 2. The saccharified feedstock is concentrated 210 under vacuum to remove solvents. In case of post-fermented feedstock, solvents including éthanol could be removed under vacuum or distilled away from the bulk of the solution and collected, leaving behind a solution (e.g., distillate bottom) comprising sugars where at least about 80 wt.% of the sugars are xylose (e.g., at least 85 wt.%, at least 90 wt.%, at least 95 wt.%, at least 96 wt.%, at least 97 wt.% or even at least 98 wt.%) and about 0.5 wt.% of the sugars are arabinose (e.g., about 1 to 0 wt.%, about 1 to 0.1 wt.%, about 0.8 to 0.1 wt.%, about 0.8 to 0.2 wt.%, about 0.5 to 1.0 wt.%, about 0.1 to 0.5 wt.%).
[0034] Some impurities (e.g., bi-products) are then precipitated 215 from the solution. This can be done by dilution with methanol, which induces précipitation of some impurities. The précipitâtes can be removed 220, for example, by use of a centrifuged and/or filtration. The filtered solution may then be decolorized 225 with activated carbon. The decolorizing agent is removed by filtration 230. A concentration step, 235 includes placing the solution under vacuum which removes methanol. The resulting solution can then be diluted with deionized water and subjected to electrodialysis 240 to remove the salts.
[0035] A possible process for purifying an ionizable organic product (e.g., D- or Llactic acid, succinic acid, tartane acid) starts with saccharifying a biomass before fermentation and then introducing it to two steps of electrodialysis, as shown in FIG. 4. The saccharified feedstock is concentrated (410) under vacuum to remove solvents. Following saccharification the biomass is fermented (415) where the microorganism converts one sugar to a desired product while leaving other sugars unconverted. Prior to the electrodialysis steps the solids are removed from the fermentation product (420). The
first electrodialysis is done to remove salts, especially inorganic salts (425). Then a bipolar membrane electrodialysis (430) is done to isolate the ionizable organic product (in this case, D- or L-lactic acid) from the unreacted sugars such as xylose. Subséquent purification (435) of the ionizable organic product by simulated moving bed chromatography or similar isolation processes can lead to an isolated product of sufficient purity for its intended use.
[0036] Pertaining to FIG 6 two electrodialysis steps are shown as a purification strategy. To the fermentation product liquid mixture which has had solids removed from it (510), is added a base if needed to convert the organic acid to its sait form (520) and electrodialysis processing is done to separate the nonionic sugars from the salts (including the organic acid salts). Then the sait is processed in the bipolar membrane electrodialysis unit (530) in which the organic acid sait is converted to its neutralized form and isolated from the salts.
[0037] Also présent in the sugar solution, for example, prior to electrodialysis and/or some other purification method as described herein is applied, there can be intact or denatured enzymes utilized in the processing, or compounds derived from these enzymes (e.g., proteinaceous material such as proteins and amino acids). These can be dissolved/and or precipitated and suspended solids, can subsequently be removed by filtration or centrifugation. In some cases, the enzymes can be présent in a functioning state and are denatured, e.g., by adding an acid, a base, heating, adding a denaturing agent. Denaturing the enzyme can facilitate its removal, e.g., by the methods described herein. The sugar solutions can hâve, for example, up to about 10 wt.% enzymes (e.g., up to 9 wt. %, up to 8 wt. %, up to 5 wt. %, up to 2 wt. %, up to 1 wt. %, between about 0.1 and 5 wL %, between about 1 wt. % and 5 wt. %, between about 2 wt. % and 5 wt. %, between about 0.1 wt. % and 1 wt. %, between about 0.01 wt. % and 1 wt. %, between about 0.001 wt.% and 0.1 wt.%). Wherein the wt. % of enzymes is understood as the wt. % of proteinaceous material in the aqueous solution.
[0038] Some cellulolytic enzymes utilized for saccharification of a biomass operate best in the acidic région, e.g., between about pH 2 and 6 (e.g., between about 3 and 6, between about, 4 and 6, between about 4 and 5). The sugar solutions can be subjected to electrodialysis at these acidic pH, or optionally the pH can be adjusted up or down after saccharification and/or saccharification can be done at a higher or lower pH. Adjustment of the pH adds to the concentrations of ions in the solution. However, electrodialysis works well at pH values selected from a broad range.
[0039] Solid impurities may be removed easily via filtration or centrifugation. Some of the dissolved impurities maybe precipitated out by treating the solution with solvents such as methanol, éthanol, isopropanol, acetone, ethyl ether and tetrahydrofuran and then removing the précipitâtes via filtration or centrifugation.
[0040] The sugar solutions derived from the processes described herein and used in the electrodialysis Systems can include non-sugar suspended or dissolved solids présent at concentrations up to about 50 wt.%, for example between about 1 and 50 wt.%, 2 and 40 wt. %, 3 and 25 wt.%, 5 and 25 wt.%, 40 and 50 wt.%, 30 and 40 wL%, 10 and 20 wt.%, 1 and 5 wt.%, 10 and 40 wt.%, less than about 50 wt.%, less than about 40 wt.%, less than about 30 wt.%, less than about 20 wt.%, less than about 10 wt.%, less than about 5 wt.%, less than about 1 wt.%, less than about 0.5 wt.%, less than about 0.01 wt.%. These solutions can hâve high turbidity, for example, at least about 5 nephelometric turbidity units (NTU) (e.g., at least about 10 NTU, at least about 50 NTU, at least about 100 NTU, at least about 100 NTU, at least about 200 NTU, at least about 300 NTU, at least about 400 NTU and even greater than about 500 NTU). In some cases the solids are completely or partially removed prior to the solution being subjected to electrodialysis. For example, the solids can be removed by filtration, centrifuging, settling, floatation and combinations of these. In some cases the solids are derived from a previously soluble material that has been precipitated, for example, an enzyme that has been denatured. After removing the solids the turbidity of the solutions can be reduced by up to about 500 NTU (e.g., reduced by up to about 100 NTU, reduced by up to about 50 NTU, reduced by up to about 5 NTU).
[0041] In addition to being turbid, the sugar solutions produced from the processes described herein can be colored due to colored impurities (e.g., colored bodies) such as aromatic chromophores. For example, some métal ions and polyphenols and ligninderived products produced or released during the processing of a lignocellulosic biomass can be highly colored. The solutions can be used directly in the electrodialysis system described herein or can be partially or completely decolorized prior to being used. For example, the colored impurities can be filtered out of the solution, destroyed (e.g., by chemical décomposition) and/or precipitated out of the solution. Some possible color removing agents that can be used are powdered, granular, extruded, bone char or bead activated carbon; styrenic, acrylic or magnetic resin; decolorizing clays such as bentonite, attapulgite, montmorillonite, hormite and combinations of these. After treating the solutions with these color removing agents, the color of the solution is less than about 200 (e.g., less than 100, less than 50, less than about 40, less than about 30, less than
about 20, less than about 10, less than about 5 and even less than about 1) as measured by the Platinum-Cobalt method (ASTM Test Method DI209).
[0042] The ionic strength of the biomass derived sugar solutions can be highly dépendent on the source of the biomass as well as the processing of the biomass as described herein. The solutions can be used directly or selectively or partially de-ionized prior to being used in the electrodialysis Systems described herein.
[0043] An advantage of electrodialysis over, for example, ion exchange chromatography, for removing ions in the processes described herein is throughput capacity. Ion exchange columns can become saturated quickly, requiring time consuming and costly régénération cycles, while electrodialysis can run continuously without requiring régénération, even with high conductivity process liquids. For example, solutions to be processed after the distillation steps described herein can hâve conductivities of greater than about 500 pS/cm (e.g., greater than about 1000 pS/cm, greater than about 2000 pS/cm, greater than about 3000 pS/cm, greater than about 4000 pS/cm, greater than about 5000 pS/cm, greater than about 6000 pS/cm, greater than about 7000 pS/cm, greater than about 8000 pS/cm, greater than about 9000 pS/cm, greater than about 10,000 pS/cm) or, for example, they can hâve conductivities between about 500 and 100,000 pS/cm (e.g., between about 500 and 50,000 pS/cm, between about 1000 and 20,000 pS/cm, between about 1000 and 20,000 pS/cm, between about 1000 and 15,000 pS/cm, between about 5000 and 20,000 pS/cm, between about 5000 and 10,000 pS/cm) and can be treated effectively by electrodialysis. For example, the conductivities after processing can be reduced by at least 10 fold (e.g., at least 20 fold, at least 30 fold, at least 50 fold, at least 100 fold, at least 500 fold, at least 1000 fold). After electrodialysis the conductivities can be between about 1-100 pS/cm (e.g., between about 1-90 pS/cm, between about 1-80 pS/cm, between about 1-50 pS/cm, between about 1-30 pS/cm, between about 1-20 pS/cm, between about 2-60 pS/cm, between about 2-40 pS/cm, between about 2-20 pS/cm, between about 5-100 pS/cm, between about 5-50 pS/cm, between about 5-25 pS/cm, between about 9-90 pS/cm, between about 9-50 pS/cm, between about 9-25 pS/cm, between about 9-12 pS/cm, between about 15-60 pS/cm, between about 15-40 pS/cm, between about 15-30 pS/cm, between about 15-20 pS/cm, between about 27-100 pS/cm, between about 27-50 pS/cm, between about 27-30 pS/cm). Once the bulk of the ions hâve been removed by electrodialysis, a cation exchange column can be used. This final column is often designated as a “fînishing” column.
[0044] Electrodialysis and/or cation exchange can be effective to remove a variety of ions, for example, from biomass liquids such as saccharified biomass, fermentation liquids. In particular, the cations include alkali metals, alkali earths, transition metals, lanthanides and actinides, for example, lithium, sodium, potassium, magnésium, calcium, strontium, barium, scandium, titanium, chromium, manganèse, iron, nickel, copper, zinc, aluminum, lanthanum, cérium, uranium. Cationic and anionic sulfïdes and oxides might also be présent, and can be removed by the methods described. Anions may include fluoride, chloride, bromide, iodide, sulfate, sulfides, phosphate, nitrate, carbonate, borates (e.g., BO33·), chlorates, arsinates and aluminates. In particular, Na+, and Cl' are présent in high concentrations and a high amount, for example about at least 50 %, of these ions should be removed (e.g., about at least 80%, about at least 85%, about at least 90%, about at least 95%, about at least 98%, about at least 99%). For example, chlorine can comprise about 1/3 of ail ions présent and can act as a xylose dégradation catalyst. Other ions can be fouling to subséquent processes such as hydrogénation.
[0045] Electrodialysis and electrodialysis reversai can also be useful for removing acids. For example, minerai acids such as HCL, H2SO4, H3PO4, HNO3 can be treated. Organic acids can also be treated, for example, acetic acid, formic acid, propionic acid, butyric acid, lactic acid and the like. The acids can be partially or fully de-ionized. Bipolar membrane electrodialysis may be used for isolation of these organic acids [0046] An electrodialysis unit that can be utilized in the methods, with equipment and with Systems described herein is described in “Electrodialysis Cell Unit PCCell ED 64 0 02”, by PCCell (Germany) Verions Jan 2006 pages 1-12; the entire disclosure of which is incorporated by reference and attachment in the appendix. For example, the PCCell DE 64 described on pg. 10 of that document can be utilized to deionized saccharified materials described herein.
[0047] Some description of Electrodialysis Reversai that can be utilized in the methods, with equipment and with Systems described herein is described in “High Water Recovery with Electrodialysis Reversai”, by GE Power and Water, Technical paper 1071EN.doc, March 2010, pages 1-5; the full disclosure of which is incorporated by reference and attachment in the appendix. For example, Electrodialysis Reversai as described in the figure on page 1 of that document (figure 1 :EDR flow diagram) describes a system that can be utilized to process saccharified materials and waste streams derived from saccharified materials described herein.
[0048] Electrodialysis and Electrodialysis Reversai is described in “Electrodiolysis (ED) and Electrodialysis Reversai (EDR)”, U.S Department of the Interior, Bureau of
Réclamation, pages 1-4; the entire of which is incorporated by reference and attachment in the appendix. For example an treatment train using ail or parts of this System (e.g., including raw water pumps, débris screens, rapid mix, slow mix flocculator, basin or clarifying, gravity filters and EDR membranes) as described on page 3 of that document can be utilized to process saccharified biomass and/or saccharified biomass waste streams.
[0049] Bipolar membrane electrodialysis equipment is available from for instance, Ameridia Somerset NJ; USA. The process was described by Ameridia in Membrane and Séparation Technology News March 2006 the entire of which is incorporated by reference and attachment in the appendix.
[0050] Some more details and réitérations of processes for treating a feedstock that can be utilized, for example, with the embodiments already discussed above, or in other embodiments, are described in the following disclosures.
SYSTEMS FOR TREATING A FEEDSTOCK [0051] Purification Systems, methods and equipment (e.g., electrodialysis) can be applied to materials that hâve been processed as described above and also as described anywhere herein.
[0052] For example, processes for the conversion of a feedstocks to sugars and other products can include, for example, optionally physically pre-treating the feedstock, e.g., to reduce its size, before and/or after this treatment, optionally, treating the feedstock to reduce its recalcitrance (e.g., by irradiation), and saccharifying the feedstock to form a sugar solution (e.g., as previously described and reiterated and expanded here). Saccharification can be performed by mixing a dispersion of the feedstock in a liquid medium, e.g., water with an enzyme, as will be discussed in detail below. During or after saccharification, the mixture (e.g., if saccharification is to be partially or completely performed en route) or solution can be transported, e.g., by pipeline, railcar, truck or barge, to a manufacturing plant. At the plant, the solution can be bioprocessed, e.g., fermented, to produce a desired product or intermediate, which can then be processed further, e.g., by distillation, electrodialysis. The individual processing steps, materials used and examples of products and intermediates that may be formed will be described in detail below. Therefore, in addition to these methods, purification Systems, methods and equipment (e.g., simulated moving bed chromatography) can be applied, for example, as an additional processing step.
RADIATION TREATMENT [0053] The feedstock can be treated with radiation to modify its structure to reduce its recalcitrance. Such treatment can, for example, reduce the average molecular weight of the feedstock, change the crystalline structure of the feedstock, and/or increase the surface area and/or porosity of the feedstock. Radiation can be by, for example, électron beam, ion beam, 100 nm to 280 nm ultraviolet (UV) light, gamma or X-ray radiation. Radiation treatments and Systems for treatments are discussed in U.S. Patent 8,142,620, and U.S. Patent Application Sériés No. 12/417,731, the entire disclosures of which are incorporated herein by reference.
[0054] Each form of radiation ionizes the biomass via particular interactions, as determined by the energy of the radiation. Heavy charged particles primarily ionize matter via Coulomb scattering; furthermore, these interactions produce energetic électrons that may further ionize matter. Alpha particles are identical to the nucléus of a hélium atom and are produced by the alpha decay of various radioactive nuclei, such as isotopes of bismuth, polonium, astatine, radon, francium, radium, several actinides, such as actinium, thorium, uranium, neptunium, curium, californium, américium, and plutonium. Electrons interact via Coulomb scattering and bremsstrahlung radiation produced by changes in the velocity of électrons.
[0055] When particles are utilized, they can be neutral (uncharged), positively charged or negatively charged. When charged, the charged particles can bear a single positive or négative charge, or multiple charges, e.g., one, two, three or even four or more charges. In instances in which chain scission is desired to change the molecular structure of the carbohydrate containing material, positively charged particles may be désirable, in part, due to their acidic nature. When particles are utilized, the particles can hâve the mass of a resting électron, or greater, e.g., 500, 1000, 1500, or 2000 or more times the mass of a resting électron. For example, the particles can hâve a mass of from about 1 atomic unit to about 150 atomic units, e.g., from about 1 atomic unit to about 50 atomic units, or from about 1 to about 25, e.g., 1, 2, 3, 4, 5, 10, 12 or 15 atomic units.
[0056] Gamma radiation has the advantage of a significant pénétration depth into a variety of material in the sample.
[0057] In embodiments in which the irradiating is performed with electromagnetic radiation, the electromagnetic radiation can hâve, e.g., energy per photon (in électron volts) of greater than 102 eV, e.g., greater than 103, 104, ΙΟ5, 106, or even greater than
107 eV. In some embodiments, the electromagnetic radiation has energy per photon of between 104 and 107, e.g., between 105 and 106 eV. The electromagnetic radiation can hâve a frequency of, e.g., greater than 1016 Hz, greater than 1017 Hz, ΙΟ18, ΙΟ19, 1O20, or even greater than 1021 Hz. In some embodiments, the electromagnetic radiation has a frequency of between 1018 and 1022Hz, e.g., between 1019 to 1021 Hz.
[0058] Electron bombardaient may be performed using an électron beam device that has a nominal energy of less than 10 MeV, e.g., less than 7 MeV, less than 5 MeV, or less than 2 MeV, e.g., from about 0.5 to 1.5 MeV, from about 0.8 to 1.8 MeV, or from about 0.7 to 1 MeV. In some implémentations the nominal energy is about 500 to 800 keV.
[0059] The électron beam may hâve a relatively high total beam power (the combined beam power of ail accelerating heads, or, if multiple accelerators are used, of ail accelerators and ail heads), e.g., at least 25 kW, e.g., at least 30, 40, 50, 60, 65,70, 80, 100, 125, or 150 kW. In some cases, the power is even as high as 500 kW, 750 kW, or even 1000 kW or more. In some cases the électron beam has a beam power of 1200 kW or more, e.g., 1400, 1600,1800, or even 3000 kW.
[0060] This high total beam power is usually achieved by utilizing multiple accelerating heads. For example, the électron beam device may include two, four, or more accelerating heads. The use of multiple heads, each of which has a relatively low beam power, prevents excessive température rise in the material, thereby preventing buming of the material, and also increases the uniformity of the dose through the thickness of the layer of material.
[0061] It is generally preferred that the bed of biomass material has a relatively uniform thickness. In some embodiments the thickness is less than about 1 inch (e.g., less than about 0.75 inches, less than about 0.5 inches, less than about 0.25 inches, less than about 0.1 inches, between about 0.1 and 1 inch, between about 0.2 and 0.3 inches). [0062] It is désirable to treat the material as quickly as possible. In general, it is preferred that treatment be performed at a dose rate of greater than about 0.25 Mrad per second, e.g., greater than about 0.5,0.75, 1, 1.5, 2, 5, 7, 10, 12, 15, or even greater than about 20 Mrad per second, e.g., about 0.25 to 2 Mrad per second. Higher dose rates allow a higher throughput for a target (e.g., the desired) dose. Higher dose rates generally require higher line speeds, to avoid thermal décomposition of the material. In one implémentation, the accelerator is set for 3 MeV, 50 mA beam current, and the line speed is 24 feet/minute, for a sample thickness of about 20 mm (e.g., comminuted corn cob material with a bulk density of 0.5 g/cm3).
[0063] In some embodiments, électron bombardment is performed until the material receives a total dose of at least 0.1 Mrad, 0.25 Mrad, 1 Mrad, 5 Mrad, e.g., at least 10, 20, 30 or at least 40 Mrad. In some embodiments, the treatment is performed until the material receives a dose of from about 10 Mrad to about 50 Mrad, e.g., from about 20 Mrad to about 40 Mrad, or from about 25 Mrad to about 30 Mrad. In some implémentations, a total dose of 25 to 35 Mrad is preferred, applied ideally over a couple of passes, e.g., at 5 Mrad/pass with each pass being applied for about one second. Cooling methods, Systems and equipment can be used before, during, after and in between radiations, for example utilizing a cooling screw conveyor and/or a cooled vibratory conveyor.
[0064] Using multiple heads as discussed above, the material can be treated in multiple passes, for example, two passes at 10 to 20 Mrad/pass, e.g., 12 to 18 Mrad/pass, separated by a few seconds of cool-down, or three passes of 7 to 12 Mrad/pass, e.g., 5 to 20 Mrad/pass, 10 to 40 Mrad/pass, 9 to 11 Mrad/pass. As discussed herein, treating the material with several relatively low doses, rather than one high dose, tends to prevent overheating of the material and also increases dose uniformity through the thickness of the material. In some implémentations, the material is stirred or otherwise mixed during or after each pass and then smoothed into a uniform layer again before the next pass, to further enhance treatment uniformity.
[0065] In some embodiments, électrons are accelerated to, for example, a speed of greater than 75 percent of the speed of light, e.g., greater than 85, 90, 95, or 99 percent of the speed of light.
[0066] In some embodiments, any processing described herein occurs on lignocellulosic material that remains dry as acquired or that has been dried, e.g., using heat and/or reduced pressure. For example, in some embodiments, the cellulosic and/or lignocellulosic material has less than about 25 wL % retained water, measured at 25°C and at fifty percent relative humidity (e.g., less than about 20 wt.%, less than about 15 wt.%, less than about 14 wt.%, less than about 13 wt.%, less than about 12 wt.%, less than about 10 wt.%, less than about 9 wt.%, less than about 8 wt.%, less than about 7 wt.%, less than about 6 wt.%, less than about 5 wt.%, less than about 4 wt.%, less than about 3 wt.%, less than about 2 wt.%, less than about 1 wt.%, or less than about 0.5 wt.%.
[0067] In some embodiments, two or more ionizing sources can be used, such as two or more électron sources. For example, samples can be treated, in any order, with a beam of électrons, followed by gamma radiation and UV light having wavelengths from
about 100 nm to about 280 nm. In some embodiments, samples are treated with three ionizing radiation sources, such as a beam of électrons, gamma radiation, and energetic UV light. The biomass is conveyed through the treatment zone where it can be bombarded with électrons.
[0068] It may be advantageous to repeat the treatment to more thoroughly reduce the recalcitrance of the biomass and/or further modify the biomass. In particular, the process parameters can be adjusted after a first (e.g., second, third, fourth or more) pass depending on the recalcitrance of the material. In some embodiments, a conveyor can be used which includes a circular System where the biomass is conveyed multiple times through the various processes described above. In some other embodiments, multiple treatment devices (e.g., électron beam generators) are used to treat the biomass multiple (e.g., 2, 3, 4 or more) times. In yet other embodiments, a single électron beam generator may be the source of multiple beams (e.g., 2, 3, 4 or more beams) that can be used for treatment of the biomass.
[0069] The effectiveness in changing the molecular/supermolecular structure and/or reducing the recalcitrance of the carbohydrate-containing biomass dépends on the électron energy used and the dose applied, while exposure time dépends on the power and dose. In some embodiments, the dose rate and total dose are adjusted so as not to destroy (e.g., char or bum) the biomass material. For example, the carbohydrates should not be damaged in the processing so that they can be released from the biomass intact, e.g. as monomeric sugars.
[0070] In some embodiments, the treatment (with any électron source or a combination of sources) is performed until the material receives a dose of at least about 0.05 Mrad, e.g., at least about 0.1, 0.25, 0.5, 0.75,1.0, 2.5, 5.0, 7.5, 10.0, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175, or 200 Mrad. In some embodiments, the treatment is performed until the material receives a dose of between 0.1-100 Mrad, 1200, 5-200, 10-200, 5-150, 50-150 Mrad, 5-100, 5-50, 5-40,10-50, 10-75, 15-50, 20-35 Mrad.
[0071] In some embodiments, relatively low doses of radiation are utilized, e.g., to increase the molecular weight of a cellulosic or lignocellulosic material (with any radiation source or a combination of sources described herein). For example, a dose of at least about 0.05 Mrad, e.g., at least about 0.1 Mrad or at least about 0.25, 0.5, 0.75. 1.0, 1.5, 2.0,2.5, 3.0, 3.5,4.0, or at least about 5.0 Mrad. In some embodiments, the irradiation is performed until the material receives a dose of between 0.1 Mrad and 2.0 Mrad, e.g., between 0.5 Mrad and 4.0 Mrad or between 1.0 Mrad and 3.0 Mrad.
[0072] It also can be désirable to irradiate from multiple directions, simultaneously or sequentially, in order to achieve a desired degree of pénétration of radiation into the material. For example, depending on the density and moisture content of the material, such as wood, and the type of radiation source used (e.g., gamma or électron beam), the 5 maximum pénétration of radiation into the material may be only about 0.75 inch. In such a case, a thicker section (up to 1.5 inch) can be irradiated by first irradiating the material from one side, and then tuming the material over and irradiating from the other side. Irradiation from multiple directions can be particulariy useful with électron beam radiation, which irradiâtes faster than gamma radiation but typically does not achieve as great a pénétration depth.
RADIATION OPAQUE MATERIALS [0073] The radiation step can include processing a material in a vault and/or bunker that is constructed using radiation opaque materials. In some implémentations, the radiation opaque materials are selected to be capable of shielding the components from X-rays with high energy (short wavelength), which can penetrate many materials. One important factor in designing a radiation shielding enclosure is the atténuation length of the materials used, which will détermine the required thickness for a particular material, blend of materials, or layered structure. The atténuation length is the pénétration distance at which the radiation is reduced to approximately 1/e (e = Euler’s number) times that of the incident radiation. Although virtually ail materials are radiation opaque if thick enough, materials containing a high compositional percentage (e.g., density) of éléments that hâve a high Z value (atomic number) hâve a shorter radiation atténuation length and thus if such materials are used a thinner, lighter shielding can be provided. Examples of high Z value materials that are used in radiation shielding are tantalum and lead. Another important parameter in radiation shielding is the halving distance, which is the thickness of a particular material that will reduce gamma ray intensity by 50%. As an example for X-ray radiation with an energy of 0.1 MeV the halving thickness is about 15.1 mm for concrète and about 2.7 mm for lead, while with an X-ray energy of 1 MeV the halving thickness for concrète is about 44.45 mm and for lead is about 7.9 mm. Radiation opaque materials can be materials that are thick or thin so long as they can reduce the radiation that passes through to the other side. Thus, if it is desired that a particular enclosure hâve a low wall thickness, e.g., for light weight or due to size constraints, the material chosen should hâve a sufficient Z value and/or atténuation
length so that its halving length is less than or equal to the desired wall thickness of the enclosure.
[0074] In some cases, the radiation opaque material may be a layered material, for example, having a layer of a higher Z value material, to provide good shielding, and a layer of a lower Z value material to provide other properties (e.g., structural integrity, impact résistance, etc.). In some cases, the layered material may be a graded-Z laminate, e.g., încluding a laminate in which the layers provide a gradient from high-Z through successively lower-Z éléments. As previously described herein, in some cases the radiation opaque materials can be interlocking blocks, for example, lead and/or concrète blocks can be supplied by NELCO Worldwide (Burlington, MA), and reconfigurable vaults can be utilized.
[0075] A radiation opaque material can reduce the radiation passing through a structure (e.g., a wall, door, ceiling, enclosure, a sériés of these or combinations of these) formed of the material by about at least about 10 %, (e.g., at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least about 99.9%, at least about 99.99%, at least about 99.999%) as compared to the incident radiation. Therefore, an enclosure made of a radiation opaque material can reduce the exposure of equipment/system/components by the same amount. Radiation opaque materials can include stainless steel, metals with Z values above 25 (e.g., lead, iron), concrète, dirt, sand and combinations thereof. Radiation opaque materials can include a barrier in the direction of the incident radiation of at least about 1mm (e.g., 5 mm, 10mm, 5 cm, 10 cm, 100cm, lm, 10m).
RADIATION SOURCES [0076] The type of radiation détermines the kinds of radiation sources used as well as 30 the radiation devices and associated equipment. The methods, Systems and equipment described herein, for example, for treating materials with radiation, can utilize sources as described herein as well as any other useful sources.
[0077] Sources of gamma rays include radioactive nuclei, such as isotopes of cobalt, calcium, technetium, chromium, gallium, indium, iodine, iron, krypton, samarium, sélénium, sodium, thallium, and xénon.
[0078] Sources of X-rays include électron beam collision with métal targets, such as tungsten or molybdenum or alloys, or compact light sources, such as those produced commercially by Lyncean.
[0079] Alpha particles are identical to the nucléus of a hélium atom and are produced by the alpha decay of various radioactive nuclei, such as isotopes of bismuth, polonium, astatine, radon, francium, radium, several actinides, such as actinium, thorium, uranium, neptunium, curium, californium, américium, and plutonium.
[0080] Sources for ultraviolet radiation include deuterium or cadmium lamps. [0081] Sources for infrared radiation include sapphire, zinc, or selenide window ceramic lamps.
[0082] Sources for microwaves include klystrons, Slevin type RF sources, or atom beam sources that employ hydrogen, oxygen, or nitrogen gases.
[0083] Accelerators used to accelerate the particles (e.g., électrons or ions) can be DC (e.g., eleetrostatic DC or electrodynamic DC), RF linear, magnetic induction linear or continuous wave. For example, various irradiating devices may be used in the methods disclosed herein, including field ionization sources, eleetrostatic ion separators, field ionization generators, thermionic émission sources, microwave discharge ion sources, recirculating or static accelerators, dynamic linear accelerators, van de Graaff accelerators, Cockroft Walton accelerators (e.g., PELLETRON® accelerators), LINACS, Dynamitions (e.g., DYNAMITRON® accelerators), cyclotrons, synchrotrons, betatrons, transformer-type accelerators, microtrons, plasma generators, cascade accelerators, and folded tandem accelerators. For example, cyclotron type accelerators are available from IBA, Belgium, such as the RHODOTRON™ system, while DC type accelerators are available from RDI, now IBA Industrial, such as the DYNAMITRON®. Other suitable accelerator Systems include, for example: DC insulated core transformer (ICT) type Systems, available from Nissin High Voltage, Japan; S-band LINACs, available from L3PSD (USA), Linac Systems (France), Mevex (Canada), and Mitsubishi Heavy Industries (Japan); L-band LINACs, available from Iotron Industries (Canada); and ILU-based accelerators, available from Budker Laboratoires (Russia). Ions and ion accelerators are discussed in Introductory Nuclear Physics, Kenneth S. Krane, John Wiley & Sons, Inc. (1988), Krsto Prelec, FIZIKA B 6 (1997) 4, 177-206, Chu, William T., “Overview of Light-Ion Beam Therapy”, Columbus-Ohio, ICRU-IAEA Meeting, 18-20 March 2006, Iwata, Y. et al., “Altemating-Phase-Focused IH-DTL for Heavy-Ion Medical Accelerators”, Proceedings of EPAC 2006, Edinburgh, Scotland, and Leitner, C.M. et al., “Status of the Superconducting ECR Ion Source Venus”, Proceedings of EPAC 2000,
Vienna, Austria. Some particle accelerators and their uses are disclosed, for example, in U.S. Pat. No. 7,931,784 to Medoff, the complété disclosure of which is incorporated herein by reference.
[0084] Electrons may be produced by radioactive nuclei that undergo beta decay, such as isotopes of iodine, césium, technetium, and iridium. Alternatively, an électron gun can be used as an électron source via thermionic émission and accelerated through an accelerating potential. An électron gun générâtes électrons, which are then accelerated through a large potential (e.g., greater than about 500 thousand, greater than about 1 million, greater than about 2 million, greater than about 5 million, greater than about 6 million, greater than about 7 million, greater than about 8 million, greater than about 9 million, or even greater than 10 million volts) and then scanned magnetically in the x-y plane, where the électrons are initially accelerated in the z direction down the accelerator tube and extracted through a foil window. Scanning the électron beams is useful for increasing the irradiation surface when irradiating materials, e.g., a biomass, that is conveyed through the scanned beam. Scanning the électron beam also distributes the thermal load homogenously on the window and helps reduce the foil window rupture due to local heating by the électron beam. Window foil rupture is a cause of significant down-time due to subséquent necessary repairs and re-starting the électron gun.
[0085] Various other irradiating devices may be used in the methods disclosed herein, including field ionization sources, electrostatic ion separators, field ionization generators, thermionic émission sources, microwave discharge ion sources, recirculating or static accelerators, dynamic linear accelerators, van de Graaff accelerators, and folded tandem accelerators. Such devices are disclosed, for example, in U.S. Pat. No. 7,931,784 to Medoff, the complété disclosure of which is incorporated herein by reference.
[0086] A beam of électrons can be used as the radiation source. A beam of électrons has the advantages of high dose rates (e.g., 1, 5, or even 10 Mrad per second), high throughput, less containment, and less confinement equipment. Electron beams can also hâve high electrical efficiency (e.g., 80%), allowing for lower energy usage relative to other radiation methods, which can translate into a lower cost of operation and lower greenhouse gas émissions corresponding to the smaller amount of energy used. Electron beams can be generated, e.g., by electrostatic generators, cascade generators, transformer generators, low energy accelerators with a scanning system, low energy accelerators with a linear cathode, linear accelerators, and pulsed accelerators.
[0087] Electrons can also be more efficient at causing changes in the molecular structure of carbohydrate-containing materials, for example, by the mechanism of chain
scission. In addition, électrons having energies of 0.5-10 MeV can penetrate low density materials, such as the biomass materials described herein, e.g., materials having a bulk density of less than 0.5 g/cm3, and a depth of 0.3-10 cm. Electrons as an ionizing radiation source can be useful, e.g., for relatively thin piles, layers or beds of materials, e.g., less than about 0.5 inch, e.g., less than about 0.4 inch, 0.3 inch, 0.25 inch, or less than about 0.1 inch. In some embodiments, the energy of each électron of the électron beam is from about 0.3 MeV to about 2.0 MeV (million électron volts), e.g., from about 0.5 MeV to about 1.5 MeV, or from about 0.7 MeV to about 1.25 MeV. Methods of irradiating materials are discussed in U.S. Pat. App. Pub. 2012/0100577 Al, filed October 18, 2011, the entire disclosure of which is herein incorporated by reference. [0088] Electron beam irradiation devices may be procured commercially or built. For example éléments or components such inductors, capacitors, casings, power sources, cables, wiring, voltage control Systems, current control éléments, insulating material, microcontrollers and cooling equipment can be purchased and assembled into a device. Optionally, a commercial device can be modified and/or adapted. For example, devices and components can be purchased from any of the commercial sources described herein including Ion Beam Applications (Louvain-la-Neuve, Belgium), NHV Corporation (Japan), the Titan Corporation (San Diego, CA), Vivirad High Voltage Corp (Billerica, MA) and/or Budker Laboratoires (Russia). Typical électron energies can be 0.5 MeV, 1 MeV, 2 MeV, 4.5 MeV, 7.5 MeV, or 10 MeV. Typical électron beam irradiation device power can be 1 kW, 5 kW, 10 kW, 20 kW, 50 kW, 60 kW, 70 kW, 80 kW, 90 kW, 100 kW, 125 kW, 150 kW, 175 kW, 200 kW, 250 kW, 300 kW, 350 kW, 400 kW, 450 kW, 500 kW, 600 kW, 700 kW, 800 kW, 900 kW or even 1000 kW. Accelerators that can be used include NHV irradiators medium energy sériés EPS-500 (e.g., 500 kV accelerator voltage and 65, 100 or 150 mA beam current), EPS-800 (e.g., 800 kV accelerator voltage and 65 or 100 mA beam current), or EPS-1000 (e.g., 1000 kV accelerator voltage and 65 or 100 mA beam current). Also, accelerators from NHV’s high energy sériés can be used such as EPS-1500 (e.g., 1500 kV accelerator voltage and 65 mA beam current), EPS-2000 (e.g., 2000 kV accelerator voltage and 50 mA beam current), EPS-3000 (e.g., 3000 kV accelerator voltage and 50 mA beam current) and EPS-5000 (e.g., 5000 and 30 mA beam current).
[0089] Tradeoffs in considering électron beam irradiation device power spécifications include cost to operate, capital costs, dépréciation, and device footprint. Tradeoffs in considering exposure dose levels of électron beam irradiation would be energy costs and environment, safety, and health (ESH) concems. Typically, generators
are housed in a vault, e.g., of lead or concrète, especially for production from X-rays that are generated in the process. Tradeoffs in considering électron energies include energy costs.
[0090] The électron beam irradiation device can produce either a fixed beam or a scanning beam. A scanning beam may be advantageous with large scan sweep length and high scan speeds, as this would effectively replace a large, fixed beam width. Further, available sweep widths of 0.5 m, 1 m, 2 m or more are available. The scanning beam is preferred in most embodiments describe herein because of the larger scan width and reduced possibility of local heating and failure of the Windows.
ELECTRON GUNS - WINDOWS [0091] The extraction System for an électron accelerator can include two window foils. The cooling gas in the two foil window extraction System can be a purge gas or a 15 mixture, for example, air, or a pure gas. In one embodiment the gas is an inert gas such as nitrogen, argon, hélium and or carbon dioxide. It is preferred to use a gas rather than a liquid since energy losses to the électron beam are minimized. Mixtures of pure gas can also be used, either pre-mixed or mixed in line prior to impinging on the Windows or in 20 the space between the Windows. The cooling gas can be cooled, for example, by using a heat exchange System (e.g., a chiller) and/or by using boil off from a condensed gas (e.g., liquid nitrogen, liquid hélium). Window foils are described in PCT/US2013/64332 filed October 10, 2013 the full disclosure of which is incorporated by reference herein.
HEATING AND THROUGHPUT DURING RADIATION TREATMENT [0092] Several processes can occur in biomass when électrons from an électron beam interact with matter in inelastic collisions. For example, ionization of the material, chain scission of polymers in the material, cross linking of polymers in the material, oxidation of the material, génération of X-rays (“Bremsstrahlung”) and vibrational excitation of molécules (e.g. phonon génération). Without being bound to a particular mechanism, the réduction in recalcitrance can be due to several of these inelastic collision effects, for example, ionization, chain scission of polymers, oxidation and phonon génération. Some of the effects (e.g., especially X-ray génération), necessitate shielding and engineering barriers, for example, enclosing the irradiation processes in a concrète (or other radiation opaque material) vault. Another effect of irradiation, vibrational excitation, is équivalent
to heating up the sample. Heating the sample by irradiation can help in recalcitrance réduction, but excessive heating can destroy the material, as will be explained below. [0093] The adiabatic température rise (ΔΤ) from adsorption of ionizing radiation is given by the équation: ΔΤ = D/Cp : where D is the average dose in kGy, Cp is the heat capacity in J/g °C, and ΔΤ is the change in température in °C. A typical dry biomass material will hâve a heat capacity close to 2. Wet biomass will hâve a higher heat capacity dépendent on the amount of water since the heat capacity of water is very high (4.19 J/g °C). Metals hâve much lower heat capacities, for example, 304 stainless steel has a heat capacity of 0.5 J/g °C. The température change due to the instant adsorption of radiation in a biomass and stainless steel for various doses of radiation is shown below.
Calculated Température increase for biomass and stainless steel.
| Dose (Mrad) | Estimated Biomass ΔΤ (°C) | Steel ΔΤ (°C) |
| 10 | 50 | 200 |
| 50 | 250, Décomposition | 1000 |
| 100 | 500, Décomposition | 2000 |
| 150 | 750, Décomposition | 3000 |
| 200 | 1000, Décomposition | 4000 |
[0094] High températures can destroy and or modify the biopolymers in biomass so that the polymers (e.g., cellulose) are unsuitable for further processing. A biomass subjected to high températures can become dark, sticky and give off odors indicating décomposition. The stickiness can even make the material hard to convey. The odors can be unpleasant and be a safety issue. In fact, keeping the biomass below about 200°C has been found to be bénéficiai in the processes described herein (e.g., below about 190°C, below about 180°C, below about 170°C, below about 160°C, below about 150°C, below about 140°C, below about 130°C, below about 120°C, below about 110°C, between about 60°C and 180°C, between about 60°C and 160°C, between about 60°C and 150°C, between about 60°C and 140°C, between about 60°C and 130°C, between about 60°C and 120°C, between about 80°C and 180°C, between about 100°C and 180°C, between about 120°C and 180°C, between about 140°C and 180°C, between about 160°C and 180°C, between about 100°C and 140°C, between about 80°C and 120°C).
[0095] It has been found that irradiation above about 10 Mrad is désirable for the processes described herein (e.g., réduction of recalcitrance). A high throughput is also désirable so that the irradiation does not become a bottle neck in processing the biomass.
The treatment is govemed by a Dose rate équation: M = FP/Dtime, where M is the mass of irradiated material (kg), F is the fraction of power that is adsorbed (unit less), P is the emitted power (kW=Voltage in MeV x Current in mA), time is the treatment time (sec) and D is the adsorbed dose (kGy). In an exemplary process where the fraction of adsorbed power is fixed, the Power emitted is constant and a set dosage is desired, the throughput (e.g., M, the biomass processed) can be increased by increasing the irradiation time. However, increasing the irradiation time without allowing the material to cool, can excessively heat the material as exemplified by the calculations shown above. Since biomass has a low thermal conductivity (less than about 0.1 Wnf’lC1), heat dissipation is slow, unlike, for example, metals (greater than about 10 Wrri’K'1) which can dissipate energy quickly as long as there is a heat sink to transfer the energy to.
ELECTRON GUNS - BEAM STOPS [0096] In some embodiments the Systems and methods include a beam stop (e.g., a shutter). For example, the beam stop can be used to quickly stop or reduce the irradiation of material without powering down the électron beam device. Altematively the beam stop can be used while powering up the électron beam, e.g., the beam stop can stop the électron beam until a beam current of a desired level is achieved. The beam stop can be placed between the primary foil window and a secondary foil window. For example, the beam stop can be mounted so that it is movable, that is, so that it can be moved into and out of the beam path. Even partial coverage of the beam can be used, for example, to control the dose of irradiation. The beam stop can be mounted to the floor, to a conveyor for the biomass, to a wall, to the radiation device (e.g., at the scan hom), or to any structural support. Preferably the beam stop is fixed in relation to the scan hom so that the beam can be effectively controlled by the beam stop. The beam stop can incorporate a hinge, a rail, wheels, slots, or other means allowing for its operation in moving into and out of the beam. The beam stop can be made of any material that will stop at least 5% of the électrons, e.g., at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or even about 100% of the électrons.
[0097] The beam stop can be made of a métal including, but not limited to, stainless steel, lead, iron, molybdenum, silver, gold, titanium, aluminum, tin, or alloys of these, or laminates (layered materials) made with such metals (e.g., metal-coated ceramic, metalcoated polymer, metal-coated composite, multilayered métal materials).
[0098] The beam stop can be cooled, for example, with a cooling fluid such as an aqueous solution or a gas. The beam stop can be partially or completely hollow, for example with cavities. Interior spaces of the beam stop can be used for cooling fluids and gases. The beam stop can be of any shape, including fiat, curved, round, oval, square, rectangular, beveled and wedged shapes.
[0099] The beam stop can hâve perforations so as to allow some électrons through, thus controlling (e.g., reducing) the levels of radiation across the whole area of the window, or in spécifie régions of the window. The beam stop can be a mesh formed, for example, from fibers or wires. Multiple beam stops can be used, together or independently, to control the irradiation. The beam stop can be remotely controlled, e.g., by radio signal or hard wired to a motor for moving the beam into or out of position.
BEAM DUMPS [00100] The embodiments disclosed herein can also include a beam dump when utilizing a radiation treatment. A beam dump’s purpose is to safely absorb a beam of charged particles. Like a beam stop, a beam dump can be used to block the beam of charged particles. However, a beam dump is much more robust than a beam stop, and is intended to block the full power of the électron beam for an extended period of time. They are often used to block the beam as the accelerator is powering up.
[00101] Beam dumps are also designed to accommodate the heat generated by such beams, and are usually made from materials such as copper, aluminum, carbon, béryllium, tungsten, or mercury. Beam dumps can be cooled, for example, using a cooling fluid that can be in thermal contact with the beam dump.
BIOMASS MATERIALS [00102] Lignocellulosic materials include, but are not limited to, wood, particle board, forestry wastes (e.g., sawdust, aspen wood, wood chips), grasses, (e.g., switchgrass, miscanthus, cord grass, reed canary grass), grain residues, (e.g., rice hulls, oat hulls, wheat chaff, barley hulls), agricultural waste (e.g., silage, canola straw, wheat straw, barley straw, oat straw, rice straw, jute, hemp, flax, bamboo, sisal, abaca, corn cobs, corn stover, soybean stover, corn fiber, alfalfa, hay, coconut hair), sugar processing residues (e.g., bagasse, beet pulp, agave bagasse), algae, seaweed, manure, sewage, and mixtures of any of these.
[00103] In some cases, the lignocellulosic material includes comcobs. Ground or hammermilled comcobs can be spread in a layer of relatively uniform thickness for irradiation, and after irradiation are easy to disperse in the medium for further processing. To facilitate harvest and collection, in some cases the entire corn plant is used, including the corn stalk, corn kernels, and in some cases even the root system of the plant.
[00104] Advantageously, no additional nutrients (other than a nitrogen source, e.g., urea or ammonia) are required during fermentation of comcobs or cellulosic or lignocellulosic materials containing significant amounts of comcobs.
[00105] Comcobs, before and after comminution, are also easier to convey and disperse, and hâve a lesser tendency to form explosive mixtures in air than other cellulosic or lignocellulosic materials such as hay and grasses.
[00106] Cellulosic materials include, for example, paper, paper products, paper waste, paper pulp, pigmented papers, loaded papers, coated papers, filled papers, magazines, printed matter (e.g., books, catalogs, manuals, labels, calendars, greeting cards, brochures, prospectuses, newsprint), printer paper, polycoated paper, card stock, cardboard, paperboard, materials having a high α-cellulose content such as cotton, and mixtures of any of these. For example paper products as described in U.S. App. No. 13/396,365 (“Magazine Feedstocks” by Medoff et al., filed February 14, 2012), the full disclosure of which is incorporated herein by reference.
[00107] Cellulosic materials can also include lignocellulosic materials which hâve been partially or fully de-lignified.
[00108] In some instances other biomass materials can be utilized, for example starchy materials. Starchy materials include starch itself, e.g., com starch, wheat starch, potato starch or rice starch, a dérivative of starch, or a material that includes starch, such as an edible food product or a crop. For example, the starchy material can be arracacha, buckwheat, banana, barley, cassava, kudzu, oca, sago, sorghum, regular household potatoes, sweet potato, taro, yams, or one or more beans, such as favas, lentils or peas. Blends of any two or more starchy materials are also starchy materials. Mixtures of starchy, cellulosic and or lignocellulosic materials can also be used. For example, a biomass can be an entire plant, a part of a plant or different parts of a plant, e.g., a wheat plant, cotton plant, a com plant, rice plant or a tree. The starchy materials can be treated by any of the methods described herein.
[00109] Microbial materials that can be used as feedstock can include, but are not limited to, any naturally occurring or genetically modified microorganism or organism
that contains or is capable of providing a source of carbohydrates (e.g., cellulose), for example, protists, e.g., animal protists (e.g., protozoa such as flagellâtes, amoeboids, ciliates, and sporozoa) and plant protists (e.g., algae such alveolates, chlorarachniophytes, cryptomonads, euglenids, glaucophytes, haptophytes, red algae, stramenopiles, and viridaeplantae). Other examples include seaweed, plankton (e.g., macroplankton, mesoplankton, microplankton, nanoplankton, picoplankton, and femptoplankton), phytoplankton, bacteria (e.g., gram positive bacteria, gram négative bacteria, and extremophiles), yeast and/or mixtures of these. In some instances, microbial biomass can be obtained from natural sources, e.g., the océan, lakes, bodies of water, e.g., sait water or fresh water, or on land. Altematively or in addition, microbial biomass can be obtained from culture Systems, e.g., large scale dry and wet culture and fermentation Systems.
[00110] In other embodiments, the biomass materials, such as cellulosic, starchy and lignocellulosic feedstock materials, can be obtained from transgenic microorganisms and plants that hâve been modified with respect to a wild type variety. Such modifications may be, for example, through the itérative steps of sélection and breeding to obtain desired traits in a plant. Furthermore, the plants can hâve had genetic material removed, modified, silenced and/or added with respect to the wild type variety. For example, genetically modified plants can be produced by recombinant DNA methods, where genetic modifications include introducing or modifying spécifie genes from parental varieties, or, for example, by using transgenic breeding wherein a spécifie gene or genes are introduced to a plant from a different species of plant and/or bacteria. Another way to create genetic variation is through mutation breeding wherein new alleles are artificially created from endogenous genes. The artificial genes can be created by a variety of ways including treating the plant or seeds with, for example, chemical mutagens (e.g., using alkylating agents, epoxides, alkaloids, peroxides, formaldéhyde), irradiation (e.g., X-rays, gamma rays, neutrons, beta particles, alpha particles, protons, deuterons, UV radiation) and température shocking or other extemal stressing and subséquent sélection techniques. Other methods of providing modified genes is through error prone PCR and DNA shuffling followed by insertion of the desired modified DNA into the desired plant or seed. Methods of introducing the desired genetic variation in the seed or plant include, for example, the use of a bacterial carrier, biolistics, calcium phosphate précipitation, electroporation, gene splicing, gene silencing, lipofection, microinjection and viral carriers. Additional genetically modified materials hâve been described in U.S. Application Serial No 13/396,369 filed February 14, 2012 the full
disclosure of which is incorporated herein by reference. Any of the methods described herein can be practiced with mixtures of any biomass materials described herein.
BIOMASS MATERIAL PREPARATION - MECHANICAL TREATMENTS [00111] The biomass can be in a dry form, for example with less than about 35% moisture content (e.g., less than about 20 %, less than about 15 %, less than about 10 % less than about 5 %, less than about 4%, less than about 3 %, less than about 2 % or even less than about 1 %). The biomass can also be delivered in a wet state, for example as a wet solid, a slurry or a suspension with at least about 10 wt.% solids (e.g., at least about 20 wt.%, at least about 30 wt. %, at least about 40 wt.%, at least about 50 wt.%, at least about 60 wt.%, at least about 70 wt.%).
[00112] The processes disclosed herein can utilize low bulk density materials, for example cellulosic or lignocellulosic feedstocks that hâve been physically pretreated to hâve a bulk density of less than about 0.75 g/cm3, e.g., less than about 0.7, 0.65, 0.60, 0.50, 0.35,0.25,0.20, 0.15, 0.10, 0.05 or less, e.g., less than about 0.025 g/cm3. Bulk density is determined using ASTM D1895B. Briefly, the method in volves filling a measuring cylinder of known volume with a sample and obtaining a weight of the sample. The bulk density is calculated by dividing the weight of the sample in grams by the known volume of the cylinder in cubic centimeters. If desired, low bulk density materials can be densified, for example, by methods described in U.S. Pat. No. 7,971,809 to Medoff, the full disclosure of which is hereby incorporated by reference.
[00113] In some cases, the pre-treatment processing includes screening of the biomass material. Screening can be through a mesh or perforated plate with a desired opening size, for example, less than about 6.35 mm (1/4 inch, 0.25 inch), (e.g., less than about 3.18 mm (1/8 inch, 0.125 inch), less than about 1.59 mm (1/16 inch, 0.0625 inch), is less than about 0.79 mm (1/32 inch, 0.03125 inch), e.g., less than about 0.51 mm (1/50 inch, 0.02000 inch), less than about 0.40 mm (1/64 inch, 0.015625 inch), less than about 0.23 mm (0.009 inch), less than about 0.20 mm (1/128 inch, 0.0078125 inch), less than about 0.18 mm (0.007 inch), less than about 0.13 mm (0.005 inch), or even less than about 0.10 mm (1/256 inch, 0.00390625 inch)). In one configuration the desired biomass falls through the perforations or screen and thus biomass larger than the perforations or screen are not irradiated. These larger materials can be re-processed, for example, by comminuting, or they can simply be removed from processing. In another configuration material that is larger than the perforations is irradiated and the smaller material is
removed by the screening process or recycled. In this kind of a configuration, the conveyor itself (for example a part of the conveyor) can be perforated or made with a mesh. For example, in one particular embodiment the biomass material may be wet and the perforations or mesh allow water to drain away from the biomass before irradiation. [00114] Screening of material can also be by a manual method, for example, by an operator or mechanoid (e.g., a robot equipped with a color, reflectivity or other sensor) that removes unwanted material. Screening can also be by magnetic screening wherein a magnet is disposed near the conveyed material and the magnetic material is removed magnetically.
[00115] Optional pre-treatment processing can include heating the material. For example a portion of a conveyor conveying the material or other material can be sent through a heated zone. The heated zone can be created, for example, by ER radiation, microwaves, combustion (e.g., gas, coal, oil, biomass), résistive heating and/or inductive coils. The heat can be applied from at least one side or more than one side, can be continuous or periodic and can be for only a portion of the material or ail the material. For example, a portion of the conveying trough can be heated by use of a heating jacket. Heating can be, for example, for the purpose of drying the material. In the case of drying the material, this can also be facilitated, with or without heating, by the movement of a gas (e.g., air, oxygen, nitrogen, He, CO2, Argon) over and/or through the biomass as it is being conveyed.
[00116] Optionally, pre-treatment processing can include cooling the material. Cooling material is described in US Pat No. 7,900,857 to Medoff, the disclosure of which in incorporated herein by reference. For example, cooling can be by supplying a cooling fluid, for example water (e.g., with glycerol), or nitrogen (e.g., liquid nitrogen) to the bottom of the conveying trough. Altematively, a cooling gas, for example, chilled nitrogen can be blown over tbe biomass materials or under the conveying system.
[00117] Another optional pre-treatment processing method can include adding a material to the biomass or other feedstocks. The additional material can be added by, for example, by showering, sprinkling and or pouring the material onto the biomass as it is conveyed. Materials that can be added include, for example, metals, ceramics and/or ions as described in U.S. Pat. App. Pub. 2010/0105119 Al (filed October 26, 2009) and U.S. Pat. App. Pub. 2010/0159569 Al (filed December 16, 2009), the entire disclosures of which are incorporated herein by reference. Optional materials that can be added include acids and bases. Other materials that can be added are oxidants (e.g., peroxides, chlorates), polymers, polymerizable monomers (e.g., containing unsaturated bonds),
water, catalysts, enzymes and/or organisms. Materials can be added, for example, in pure form, as a solution in a solvent (e.g., water or an organic solvent) and/or as a solution. In some cases the solvent is volatile and can be made to evaporate e.g., by heating and/or blowing gas as previously described. The added material may form a uniform coating on the biomass or be a homogeneous mixture of different components (e.g., biomass and additional material). The added material can modulate the subséquent irradiation step by increasing the efficiency of the irradiation, damping the irradiation or changing the effect of the irradiation (e.g., from électron beams to X-rays or heat). The method may hâve no impact on the irradiation but may be useful for further downstream processing. The added material may help in conveying the material, for example, by lowering dust levels.
[00118] Biomass can be delivered to a conveyor (e.g., vibratory conveyors used in the vaults herein described) by a belt conveyor, a pneumatic conveyor, a screw conveyor, a hopper, a pipe, manually or by a combination of these. The biomass can, for example, be dropped, poured and/or placed onto the conveyor by any of these methods. In some embodiments, the material is delivered to the conveyor using an enclosed material distribution system to help maintain a low oxygen atmosphère and/or control dust and fines. Lofted or air suspended biomass fines and dust are undesirable because these can form an explosion hazard or damage the window foils of an électron gun (if such a device is used for treating the material).
[00119] The material can be leveled to form a uniform thickness between about 0.0312 and 5 inches (e.g., between about 0.0625 and 2.000 inches, between about 0.125 and 1 inches, between about 0.125 and 0.5 inches, between about 0.3 and 0.9 inches, between about 0.2 and 0.5 inches between about 0.25 and 1.0 inches, between about 0.25 and 0.5 inches, 0.100 +/- 0.025 inches, 0.150 +/- 0.025 inches, 0.200 +/- 0.025 inches, 0.250 +/- 0.025 inches, 0.300 +/- 0.025 inches, 0.350 +/- 0.025 inches, 0.400 +/- 0.025 inches, 0.450 +/- 0.025 inches, 0.500 +/- 0.025 inches, 0.550 +/- 0.025 inches, 0.600 +/0.025 inches, 0.700 +/- 0.025 inches, 0.750 +/- 0.025 inches, 0.800 +/- 0.025 inches, 0.850 +/- 0.025 inches, 0.900 +/- 0.025 inches, 0.900 +/- 0.025 inches.
[00120] Generally, it is preferred to convey the material as quickly as possible through the électron beam to maximize throughput. For example, the material can be conveyed at rates of at least 1 ft/min, e.g., at least 2 ft/min, at least 3 ft/min, at least 4 ft/min, at least 5 ft/min, at least 10 ft/min, at least 15 ft/min, 20, 25, 30, 35,40, 45, 50 ft/min. The rate of conveying is related to the beam current, for example, for a lA inch thick biomass and 100 mA, the conveyor can move at about 20 ft/min to provide a useful irradiation
dosage, at 50 mA the conveyor can move at about 10 ft/min to provide approximately the same irradiation dosage.
[00121] After the biomass material has been conveyed through the radiation zone, optional post-treatment processing can be done. The optional post-treatment processing can, for example, be a process described with respect to the pre-irradiation processing. For example, the biomass can be screened, heated, cooled, and/or combined with additives. Uniquely to post-irradiation, quenching of the radicals can occur, for example, quenching of radicals by the addition of fluids or gases (e.g., oxygen, nitrous oxide, ammonia, liquids), using pressure, heat, and/or the addition of radical scavengers. For example, the biomass can be conveyed out of the enclosed conveyor and exposed to a gas (e.g., oxygen) where it is quenched, forming caboxylated groups. In one embodiment the biomass is exposed during irradiation to the reactive gas or fluid. Quenching of biomass that has been irradiated is described in U.S. Pat. No. 8,083,906 to Medoff, the entire disclosure of which is incorporate herein by reference.
[00122] If desired, one or more mechanical treatments can be used in addition to irradiation to further reduce the recalcitrance of the carbohydrate-containing material. These processes can be applied before, during and or after irradiation.
[00123] In some cases, the mechanical treatment may include an initial préparation of the feedstock as received, e.g., size réduction of materials, such as by comminution, e.g., cutting, grinding, shearing, pulverizing or chopping. For example, in some cases, loose feedstock (e.g., recycled paper, starchy materials, or switchgrass) is prepared by shearing or shredding. Mechanical treatment may reduce the bulk density of the carbohydratecontaining material, increase the surface area of the carbohydrate-containing material and/or decrease one or more dimensions of the carbohydrate-containing material.
[00124] Altematively, or in addition, the feedstock material can be treated with another treatment, for example, chemical treatments, such as one with an acid (HCl, H2SO4, H3PO4), a base (e.g., KOH and NaOH), a chemical oxidant (e.g., peroxides, chlorates, ozone), irradiation, steam explosion, pyrolysis, sonication, oxidation, chemical treatment. The treatments can be in any order and in any sequence and combinations. For example, the feedstock material can first be physically treated by one or more treatment methods, e.g., chemical treatment including and in combination with acid hydrolysis (e.g., utilizing HCl, H2SO4, H3PO4), radiation, sonication, oxidation, pyrolysis or steam explosion, and then mechanically treated. This sequence can be advantageous since materials treated by one or more of the other treatments, e.g., irradiation or pyrolysis, tend to be more brittle and, therefore, it may be easier to further change the structure of
the material by mechanical treatment. As another example, a feedstock material can be conveyed through ionizing radiation using a conveyor as described herein and then mechanically treated. Chemical treatment can remove some or ail of the lignin (for example, chemical pulping) and can partially or completely hydrolyze the material. The methods also can be used with pre-hydrolyzed material. The methods also can be used with material that has not been pre hydrolyzed. The methods can be used with mixtures of hydrolyzed and non-hydrolyzed materials, for example, with about 50% or more nonhydrolyzed material, with about 60% or more non- hydrolyzed material, with about 70% or more non-hydrolyzed material, with about 80% or more non-hydrolyzed material or even with 90% or more non-hydrolyzed material.
[00125] In addition to size réduction, which can be performed initially and/or later in processing, mechanical treatment can also be advantageous for “opening up,” “stressing,” breaking or shattering the carbohydrate-containing materials, making the cellulose of the materials more susceptible to chain scission and/or disruption of crystalline structure during the physical treatment.
[00126] Methods of mechanically treating the carbohydrate-containing material include, for example, milling or grinding. Milling may be performed using, for example, a hammer mill, bail mill, colloid mill, conical or cône mill, disk mill, edge mill, Wiley mill, grist mill or other mill. Grinding may be performed using, for example, a cutting/impact type grinder. Some exemplary grinders include stone grinders, pin grinders, coffee grinders, and burr grinders. Grinding or milling may be provided, for example, by a reciprocating pin or other element, as is the case in a pin mill. Other mechanical treatment methods include mechanical ripping or tearing, other methods that apply pressure to the fibers, and air attrition milling. Suitable mechanical treatments further include any other technique that continues the disruption of the internai structure of the material that was initiated by the previous processing steps.
[00127] Mechanical feed préparation Systems can be configured to produce streams with spécifie characteristics such as, for example, spécifie maximum sizes, spécifie length-to-width, or spécifie surface areas ratios. Physical préparation can increase the rate of reactions, improve the movement of material on a conveyor, improve the irradiation profile of the material, improve the radiation uniformity of the material, or reduce the processing time required by opening up the materials and making them more accessible to processes and/or reagents, such as reagents in a solution.
[00128] The bulk density of feedstocks can be controlled (e.g., increased). In some situations, it can be désirable to préparé a low bulk density material, e.g., by densifying
the material (e.g., densification can make it easier and less costly to transport to another site) and then reverting the material to a lower bulk density state (e.g., after transport). The material can be densified, for example, from less than about 0.2 g/cc to more than about 0.9 g/cc (e.g., less than about 0.3 to more than about 0.5 g/cc, less than about 0.3 to more than about 0.9 g/cc, less than about 0.5 to more than about 0.9 g/cc, less than about 0.3 to more than about 0.8 g/cc, less than about 0.2 to more than about 0.5 g/cc). For example, the material can be densified by the methods and equipment disclosed in U.S. Pat. No. 7,932,065 to Medoff and International Publication No. WO 2008/073186 (which was filed October 26,2007, was published in English, and which designated the United States), the full disclosures of which are incorporated herein by reference. Densified materials can be processed by any of the methods described herein, or any material processed by any of the methods described herein can be subsequently densified.
[00129] In some embodiments, the material to be processed is in the form of a fibrous material that includes fibers provided by shearing a fiber source. For example, the shearing can be performed with a rotary knife cutter.
[00130] For example, a fiber source, e.g., that is récalcitrant or that has had its recalcitrance level reduced, can be sheared, e.g., in a rotary knife cutter, to provide a first fibrous material. The first fibrous material is passed through a first screen, e.g., having an average opening size of 1.59 mm or less (1/16 inch, 0.0625 inch), provide a second fibrous material. If desired, the fiber source can be eut prior to the shearing, e.g., with a shredder. For example, when a paper is used as the fiber source, the paper can be first eut into strips that are, e.g., 1/4- to 1/2-inch wide, using a shredder, e.g., a counterrotating screw shredder, such as those manufactured by Munson (Utica, N.Y.). As an alternative to shredding, the paper can be reduced in size by cutting to a desired size using a guillotine cutter. For example, the guillotine cutter can be used to eut the paper into sheets that are, e.g., 10 inches wide by 12 inches long.
[00131] In some embodiments, the shearing of the fiber source and the passing of the resulting first fibrous material through a first screen are performed concurrently. The shearing and the passing can also be performed in a batch-type process.
[00132] For example, a rotary knife cutter can be used to concurrently shear the fiber source and screen the first fibrous material. A rotary knife cutter includes a hopper that can be loaded with a shredded fiber source prepared by shredding a fiber source. [00133] In some implémentations, the feedstock is physically treated prior to saccharification and/or fermentation. Physical treatment processes can include one or
more of any of those described herein, such as mechanical treatment, chemical treatment, irradiation, sonication, oxidation, pyrolysis or steam explosion. Treatment methods can be used in combinations of two, three, four, or even ail of these technologies (in any order). When more than one treatment method is used, the methods can be applied at the 5 same time or at different times. Other processes that change a molecular structure of a biomass feedstock may also be used, alone or in combination with the processes disclosed herein.
[00134] Mechanical treatments that may be used, and the characteristics of the mechanically treated carbohydrate-containing materials, are described in further detail in
U.S. Pat. App. Pub. 2012/0100577 Al, filed October 18, 2011, the full disclosure of which is hereby incorporated herein by reference.
SONICATION, PYROLYSIS, OXIDATION, STEAM EXPLOSION [00135] If desired, one or more sonication, pyrolysis, oxidative, or steam explosion processes can be used instead of or in addition to irradiation to reduce or further reduce the recalcitrance of the carbohydrate-containing material. For example, these processes can be applied before, during and or after irradiation. These processes are described in 20 detail in U.S. Pat. No. 7,932,065 to Medoff, the full disclosure of which is incoiporated herein by reference.
INTERMEDIATES AND PRODUCTS [00136] Using the processes described herein, the biomass material can be converted to one or more products, such as energy, fuels, foods and materials. For example, intermediates and products such as organic acids, salts of organic acids, anhydrides, esters of organic acids and fuels, e.g., fuels for internai combustion engines or feedstocks for fuel cells. Systems and processes are described herein that can use as feedstock cellulosic and/or lignocellulosic materials that are readily available, but often can be difficult to process, e.g., municipal waste streams and waste paper streams, such as streams that include newspaper, Kraft paper, corrugated paper or mixtures of these. [00137] Spécifie examples of products include, but are not limited to, hydrogen, sugars (e.g., glucose, xylose, arabinose, mannose, galactose, fructose, disaccharides, oligosaccharides and polysaccharides), alcohols (e.g., monohydric alcohols or dihydric alcohols, such as éthanol, n-propanol, isobutanol, sec-butanol, tert-butanol or n-butanol),
hydrated or hydrous alcohols (e.g., containing greater than 10%, 20%, 30% or even greater than 40% water), biodiesel, organic acids, hydrocarbons (e.g., methane, ethane, propane, isobutene, pentane, n-hexane, biodiesel, bio-gasoline and mixtures thereof), coproducts (e.g., proteins, such as cellulolytic proteins (enzymes) or single cell proteins), and mixtures of any of these in any combination or relative concentration, and optionally in combination with any additives (e.g., fuel additives). Other examples include carboxylic acids, salts of a carboxylic acid, a mixture of carboxylic acids and salts of carboxylic acids and esters of carboxylic acids (e.g., methyl, ethyl and n-propyl esters), ketones (e.g., acetone), aldéhydes (e.g., acetaldehyde), alpha and beta unsaturated acids (e.g., acrylic acid) and olefins (e.g., ethylene). Other alcohols and alcohol dérivatives include propanol, propylene glycol, 1,4-butanediol, 1,3-propanediol, sugar alcohols (e.g., erythritol, glycol, glycerol, sorbitol threitol, arabitol, ribitol, mannitol, dulcitol, fucitol, iditol, isomalt, maltitol, lactitol, xylitol and other polyois), and methyl or ethyl esters of any of these alcohols. Other products include methyl acrylate, methyl méthacrylate, Dlactic acid, L-lactic acid pyruvic acid, polylactic acid, citric acid, formic acid, acetic acid, propionic acid, lactic acid, tartaric acid, butyric acid, succinic acid, valeric acid, caproic acid, 3-hydroxypropionic acid, palmitic acid, stearic acid, oxalic acid, malonic acid, glutaric acid, oleic acid, linoleic acid, glycolic acid, gamma-hydroxybutyric acid, and mixtures thereof, salts of any of these acids, mixtures of any of the acids and their respective salts.
[00138] Any combination of the above products with each other, and/or of the above products with other products, which other products may be made by the processes described herein or otherwise, may be packaged together and sold as products. The products may be combined, e.g., mixed, blended or co-dissolved, or may simply be packaged or sold together.
[00139] Any of the products or combinations of products described herein may be sanitized or sterilized prior to selling the products, e.g., after purification or isolation or even after packaging, to neutralize one or more potentially undesirable contaminants that could be présent in the product(s). Such sanitation can be done with électron bombardment, for example, be at a dosage of less than about 20 Mrad, e.g., from about 0.1 to 15 Mrad, from about 0.5 to 7 Mrad, or from about 1 to 3 Mrad.
[00140] The processes described herein can produce various by-product streams useful for generating steam and electricity to be used in other parts of the plant (cogénération) or sold on the open market. For example, steam generated from buming byproduct streams can be used in a distillation process. As another example, electricity
generated from buming by-product streams can be used to power électron beam generators used in pretreatment.
[00141] The by-products used to generate steam and electricity are derived from a number of sources throughout the process. For example, anaérobie digestion of wastewater can produce a biogas high in methane and a small amount of waste biomass (sludge). As another example, post-saccharification and/or post-distillate solids (e.g., unconverted lignin, cellulose, and hemicellulose remaining from the pretreatment and primary processes) can be used, e.g., bumed, as a fuel.
[00142] Other intermediates and products, including food and pharmaceutical products, are described in U.S. Pat. App. Pub. 2010/0124583 Al, published May 20, 2010, to Medoff, the full disclosure of which is hereby incorporated by reference herein.
LIGNIN DERIVED PRODUCTS [00143] The spent biomass (e.g., spent lignocellulosic material) from lignocellulosic processing by the methods described are expected to hâve a high lignin content and in addition to being useful for producing energy through combustion in a Co-Generation plant, may hâve uses as other valuable products. For example, the lignin can be used as captured as a plastic, or it can be synthetically upgraded to other plastics. In some instances, it can also be converted to lignosulfonates, which can be utilized as binders, dispersants, emulsifiers or as séquestrants.
[00144] When used as a binder, the lignin or a lignosulfonate can, e.g., be utilized in coal briquettes, in ceramics, for binding carbon black, for binding fertilizers and herbicides, as a dust suppressant, in the making of plywood and particle board, for binding animal feeds, as a binder for fiberglass, as a binder in linoléum paste and as a soil stabilizer.
[00145] When used as a dispersant, the lignin or lignosulfonates can be used, for example in, concrète mixes, clay and ceramics, dyes and pigments, leather tanning and in gypsum board.
[00146] When used as an emulsifier, the lignin or lignosulfonates can be used, e.g., in asphalt, pigments and dyes, pesticides and wax émulsions.
[00147] As a séquestrant, the lignin or lignosulfonates can be used, e.g., in micronutrient Systems, cleaning compounds and water treatment Systems, e.g., for boiler and cooling Systems.
[00148] For energy production, lignin generally has a higher energy content than holocellulose (cellulose and hemicellulose) since it contains more carbon than homocellulose. For example, dry lignin can hâve an energy content of between about 11,000 and 12,500 BTU per pound, compared to 7,000 an 8,000 BTU per pound of holocellulose. As such, lignin can be densified and converted into briquettes and pellets for buming. For example, the lignin can be converted into pellets by any method described herein. For a slower buming pellet or briquette, the lignin can be crosslinked, such as applying a radiation dose of between about 0.5 Mrad and 5 Mrad. Crosslinking can make a slower buming form factor. The form factor, such as a pellet or briquette, can be converted to a “synthetic coal” or charcoal by pyrolyzing in the absence of air, e.g., at between 400 and 950 °C. Prior to pyrolyzing, it can be désirable to crosslink the lignin to maintain structural integrity.
SACCHARIFICATION [00149] In order to convert the feedstock to a form that can be readily processed, the glucan- or xylan-containing cellulose in the feedstock can be hydrolyzed to low molecular weight carbohydrates, such as sugars, by a saccharifying agent, e.g., an enzyme or acid, a process referred to as saccharification. The low molecular weight carbohydrates can then be used, for example, in an existing manufacturing plant, such as a single cell protein plant, an enzyme manufacturing plant, or a fuel plant, e.g., an éthanol manufacturing facility.
[00150] The feedstock can be hydrolyzed using an enzyme, e.g., by combining the materials and the enzyme in a solvent, e.g., in an aqueous solution.
[00151] Alternatively, the enzymes can be supplied by organisms that break down biomass, such as the cellulose and/or the lignin portions of the biomass, contain or manufacture various cellulolytic enzymes (cellulases), ligninases or various small molécule biomass-degrading métabolites. These enzymes may be a complex of enzymes that act synergistically to dégradé crystalline cellulose or the lignin portions of biomass. Examples of cellulolytic enzymes include: endoglucanases, cellobiohydrolases, and cellobiases (beta-glucosidases).
[00152] During saccharification a cellulosic substrate can be initially hydrolyzed by endoglucanases at random locations producing oligomeric intermediates. These intermediates are then substrates for exo-splitting glucanases such as cellobiohydrolase to produce cellobiose from the ends of the cellulose polymer. Cellobiose is a water-
soluble 1,4-linked dimer of glucose. Finally, cellobiase cleaves cellobiose to yield glucose. The effîciency (e.g., time to hydrolyze and/or completeness of hydrolysis) of this process dépends on the recalcitrance of the cellulosic material.
[00153] Therefore, the treated biomass materials can be saccharified, generally by combining the material and a cellulase enzyme in a fluid medium, e.g., an aqueous solution. In some cases, the material is boiled, steeped, or cooked in hot water prior to saccharification, as described in U.S. Pat. App. Pub. 2012/0100577 Al by Medoff and Masterman, published on April 26, 2012, the entire contents of which are incorporated herein.
[00154] The saccharification process can be partially or completely performed in a tank (e.g., a tank having a volume of at least 4000, 40,000, or 500,000 L) in a manufacturing plant, and/or can be partially or completely performed in transit, e.g., in a rail car, tanker truck, or in a supertanker or the hold of a ship. The time required for complété saccharification will dépend on the process conditions and the carbohydratecontaining material and enzyme used. If saccharification is performed in a manufacturing plant under controlled conditions, the cellulose may be substantially entirely converted to sugar, e.g., glucose in about 12-96 hours. If saccharification is performed partially or completely in transit, saccharification may take longer.
[00155] It is generally preferred that the tank contents be mixed during saccharification, e.g., using jet mixing as described in International App. No. PCT/US2010/035331, filed May 18, 2010, which was published in English as WO 2010/135380 and designated the United States, the full disclosure of which is incorporated by reference herein.
[00156] The addition of surfactants can enhance the rate of saccharification. Examples of surfactants include non-ionic surfactants, such as a Tween® 20 or Tween® 80 polyethylene glycol surfactants, ionic surfactants, or amphoteric surfactants.
[00157] It is generally preferred that the concentration of the sugar solution resulting from saccharification be relatively high, e.g., greater than 40%, or greater than 50, 60, 70, 80, 90 or even greater than 95% by weight. Water may be removed, e.g., by évaporation, to increase the concentration of the sugar solution. This reduces the volume to be shipped, and also inhibits microbial growth in the solution.
[00158] Alternatively, sugar solutions of lower concentrations may be used, in which case it may be désirable to add an antimicrobial additive, e.g., a broad spectrum antibiotic, in a low concentration, e.g., 50 to 150 ppm. Other suitable antibiotics include amphotericin B, ampicillin, chloramphenicol, ciprofloxacin, gentamicin, hygromycin B,
kanamycin, neomycin, penicillin, puromycin, streptomycin. Antibiotics will inhibit growth of microorganisms during transport and storage, and can be used at appropriate concentrations, e.g., between 15 and 1000 ppm by weight, e.g., between 25 and 500 ppm, or between 50 and 150 ppm. If desired, an antibiotic can be included even if the sugar concentration is relatively high. Altematively, other additives with anti-microbial of preservative properties may be used. Preferably the antimicrobial additive(s) are foodgrade.
[00159] A relatively high concentration solution can be obtained by limiting the amount of water added to the carbohydrate-containing material with the enzyme. The concentration can be controlled, e.g., by controlling how much saccharification takes place. For example, concentration can be increased by adding more carbohydratecontaining material to the solution. In order to keep the sugar that is being produced in solution, a surfactant can be added, e.g., one of those discussed above. Solubility can also be increased by increasing the température of the solution. For example, the solution can be maintained at a température of 40-50°C, 60-80°C, or even higher.
SACCHARIFYING AGENTS [00160] Suitable cellulolytic enzymes include cellulases from species in the généra Bacillus, Coprinus, Myceliophthora, Cephalosporium, Scytalidium, Pénicillium, Aspergillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium, Chrysosporium and Trichoderma, especially those produced by a strain selected from the species Aspergillus (see, e.g., EP Pub. No. 0 458 162), Humicola insolens (reclassified as Scytalidium thermophilum, see, e.g., U.S. Pat. No. 4,435,307), Coprinus cinereus, Fusarium oxysporum, Myceliophthora thermophila, Meripilus giganteus, Thielavia terrestris, Acremonium sp. (including, but not limited to, A. persicinum, A. acremonium, A. brachypenium, A. dichromosporum, A. obclavatum, A. pinkertoniae, A. roseogriseum, A. incoloratum, and A. furatum). Preferred strains include Humicola insolens DSM 1800, Fusarium oxysporum DSM 2672, Myceliophthora thermophila CBS 117.65, Cephalosporium sp. RYM-202, Acremonium sp. CBS 478.94, Acremonium sp. CBS 265.95, Acremonium persicinum CBS 169.65, Acremonium acremonium AHU 9519, Cephalosporium sp. CBS 535.71, Acremonium brachypenium CBS 866.73, Acremonium dichromosporum CBS 683.73, Acremonium obclavatum CBS 311.74, Acremonium pinkertoniae CBS 157.70, Acremonium roseogriseum CBS 134.56, Acremonium incoloratum CBS 146.62, and Acremonium furatum CBS 299.70H. Cellulolytic
enzymes may also be obtained from Chrysosporium, preferably a strain of Chrysosporium lucknowense. Additional strains that can be used include, but are not limited to, Trichoderma (particularly T. viride, T. reesei, and T. koningii), alkalophilic Bacillus (see, for example, U.S. Pat. No. 3,844,890 and EP Pub. No. 0 458 162), and Streptomyces (see, e.g., EP Pub. No. 0 458 162).
[00161] In addition to or in combination to enzymes, acids, bases and other chemicals (e.g., oxidants) can be utilized to saccharify lignocellulosic and cellulosic materials. These can be used in any combination or sequence (e.g., before, after and/or during addition of an enzyme). For example strong minerai acids can be utilized (e.g. HCl, H2SO4, H3PO4) and strong bases (e.g., NaOH, KOH).
SUGARS [00162] In the processes described herein, for example after saccharification, sugars (e.g., glucose and xylose) can be isolated. For example sugars can be isolated by précipitation, crystallization, chromatography (e.g., simulated moving bed chromatography as described herein, high pressure chromatography), centrifugation, extraction, any other isolation method known in the art, and combinations thereof.
HYDROGENATION AND OTHER CHEMICAL TRANSFORMATIONS [00163] The processes described herein can include hydrogénation. For example glucose and xylose can be hydrogenated to sorbitol and xylitol respectively. Hydrogénation can be accomplished by use of a catalyst (e.g., Pt/gamma-ALOi, Ru/C, Raney Nickel, or other catalysts know in the art) in combination with H2 under high pressure (e.g., 10 to 12000 psi). Other types of chemical transformation of the products from the processes described herein can be used, for example production of organic sugar derived products (e.g., furfural and furfural-derived products). Chemical transformations of sugar derived products are described in USSN 13/934,704 filed July 3, 2013, the entire disclosure of which is incorporated herein by reference.
FERMENTATION [00164] Yeast and Zymomonas bacteria, for example, can be used for fermentation or conversion of sugar(s) to alcohol(s). Other microorganisms are discussed below. The
optimum pH for fermentations is about pH 4 to 7. For example, the optimum pH for yeast is from about pH 4 to 5, while the optimum pH for Zymomonas is from about pH 5 to 6. Typical fermentation times are about 24 to 168 hours (e.g., 24 to 96 hrs) with températures in the range of 20°C to 40°C (e.g., 26°C to 40°C), however thermophilic microorganisms prefer higher températures.
[00165] In some embodiments, e.g., when anaérobie organisms are used, at least a portion of the fermentation is conducted in the absence of oxygen, e.g., under a blariket of an inert gas such as N2, Ar, He, CO2 or mixtures thereof. Additionally, the mixture may hâve a constant purge of an inert gas flowing through the tank during part of or ail of the fermentation. In some cases, anaérobie condition, can be achieved or maintained by carbon dioxide production during the fermentation and no additional inert gas is needed.
[00166] In some embodiments, ail or a portion of the fermentation process can be intemipted before the low molecular weight sugar is completely converted to a product (e.g., éthanol). The intermediate fermentation products include sugar and carbohydrates in high concentrations. The sugars and carbohydrates can be îsolated via any means known in the art. These intermediate fermentation products can be used in préparation of food for human or animal consumption. Additionally or altematively, the intermediate fermentation products can be ground to a fine particle size in a stainless-steel laboratory mill to produce a flour-like substance. Jet mixing may be used during fermentation, and in some cases saccharification and fermentation are performed in the same tank.
[00167] Nutrients for the microorganisms may be added during saccharification and/or fermentation, for example the food-based nutrient packages described in U.S. Pat. App. Pub. 2012/0052536, filed July 15, 2011, the complété disclosure of which is incorporated herein by reference.
[00168] “Fermentation” includes the methods and products that are disclosed in application Nos. PCT/US2012/71093 published June 27,2013, PCT/US2012/71907 published June 27, 2012, and PCT/US2012/71083 published June 27, 2012 the contents of which are incorporated by reference herein in their entirety.
[00169] Mobile fermenters can be utilized, as described in Intemational App. No. PCT/US2007/074028 (which was filed July 20, 2007, was published in English as WO 2008/011598 and designated the United States) and has a US issued Patent No. 8,318,453, the contents of which are incorporated herein in its entirety. Similarly, the saccharification equipment can be mobile. Further, saccharification and/or fermentation may be performed in part or entirely during transit.
FERMENTATION AGENTS [00170] The microorganism(s) used in fermentation can be naturally-occurring microorganisms and/or engineered microorganisms. For example, the microorganism can be a bacterium (including, but not limited to, e.g., a cellulolytic bacterium), a fungus, (including, but not limited to, e.g., a yeast), a plant, a protist, e.g., a protozoa or a funguslike protest (including, but not limited to, e.g., a slime mold), or an alga. When the organisms are compatible, mixtures of organisms can be utilized.
[00171] Suitable fermenting microorganisms hâve the ability to convert carbohydrates, such as glucose, fructose, xylose, arabinose, mannose, galactose, oligosaccharides or polysaccharides into fermentation products. Fermenting microorganisms include strains of the genus Sacchromyces spp. (including, but not limited to, S. cerevisiae (baker’s yeast), S. distaticus, S. uvarum), the genus Kluyveromyces, (including, but not limited to, K. marxianus, K. fragilis), the genus Candida (including, but not limited to, C. pseudotropicalis, and C. brassicae), Pichia stipitis (a relative of Candida shehatae), the genus Clavispora (including, but not limited to, C. lusitaniae and C. opuntiae), the genus Pachysolen (including, but not limited to, P. tannophilus), the genus Bretannomyces (including, but not limited to, e.g., B. clausenii (Philippidis, G. P., 1996, Cellulose bioconversion technology, in Handbook on Bioethanol: Production and Utilization, Wyman, C.E., ed., Taylor & Francis, Washington, DC, 179-212)). Other suitable microorganisms include, for example, Zymomonas mobilis, Clostridium spp. (including, but not limited to, C. thermocellum (Philippidis, 1996, supra), C. saccharobutylacetonicum, C. tyrobutyricum C. saccharobutylicum, C. Puniceum, C. beijemckii, and C. acetobutylicum), Moniliella spp. (including but not limited to M. pollinis,M. tomentosa, M. madida, M. nigrescens, M. oedocephali, M. megachiliensis), Yarrowia lipolytica, Aureobasidium sp., Trichosporonoides sp., Trigonopsis variabilis, Trichosporon sp., Moniliellaacetoabutans sp., Typhula variabilis, Candida magnoliae, Ustilaginomycetes sp., Pseudozyma tsukubaensis, yeast species of généra Zygosaccharomyces, Debaryomyces, Hansenula and Pichia, and fungi of the dematioid genus Torula (e.g., T.corallina).
[00172] Additional microorganisms include the Lactobacillus group. Examples include Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus delbrueckii, Lactobacillus plantarum, Lactobacillus coryniformis, e.g., Lactobacillus coryniformis subspecies torquens, Lactobacillus pentosus, Lactobacillus brevis. Other microorganisms include Pediococus penosaceus, Rhizopus oryzae.
[00173] Many such microbial strains are publicly available, either commercially or through depositories such as the ATCC (American Type Culture Collection, Manassas, Virginia, USA), the NRRL (Agricultural Research Service Culture Collection, Peoria, Illinois, USA), or the DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany), to name a few.
[00174] Commercially available yeasts include, for example, RED STAR®/Lesaffre Ethanol Red (available from Red Star/Lesaffre, USA), FALI® (available from Fleischmann’s Yeast, a division of Bums Philip Food Inc., USA), SUPERSTART® (available from Alltech, now Lalemand), GERT STRAND® (available from Gert Strand AB, Sweden) and FERMOL® (available from DSM Specialties).
DISTILLATION [00175] After fermentation, the resulting fluids can be distilled using, for example, a “beer column” to separate éthanol and other alcohols from the majority of water and residual solids. The vapor exiting the beer column can be, e.g., 35% by weight éthanol and can be fed to a rectification column. A mixture of nearly azeotropic (92.5%) éthanol and water from the rectification column can be purified to pure (99.5%) éthanol using vapor-phase molecular sieves. The beer column bottoms can be sent to the first effect of a three-effect evaporator. The rectification column reflux condenser can provide heat for this first effect. After the first effect, solids can be separated using a centrifuge and dried in a rotary dryer. A portion (25%) of the centrifuge effluent can be recycled to fermentation and the rest sent to the second and third evaporator effects. Most of the evaporator condensate can be retumed to the process as fairly clean condensate with a small portion split off to waste water treatment to prevent build-up of low-boiling compounds.
HYDROCARBON-CONTAINING MATERIALS [00176] In other embodiments utilizing the methods and Systems described herein, hydrocarbon-containing materials, for example that are mixed with biomass can be processed. Any process described herein can be used to treat any hydrocarbon-containing material herein described. “Hydrocarbon-containing materials,” as used herein, is meant to include oil sands, oil shale, tar sands, coal dust, coal slurry, bitumen, various types of coal, and other naturally-occurring and synthetic materials that include both hydrocarbon
components and solid matter. The solid matter can include wood, rock, sand, clay, stone, silt, driiling slurry, or other solid organic and/or inorganic matter. The term can also include waste products such as driiling waste and by-products, refining waste and byproducts, or other waste products containing hydrocarbon components, such as asphalt shingling and covering, asphalt pavement, etc.
CONVEYING SYSTEMS [00177] Various conveying Systems can be used to convey the biomass material, for example, as previously discussed, to a vault, and under an électron beam in a vault. Exemplary conveyors are belt conveyors, pneumatic conveyors, screw conveyors, carts, trains, trains or carts on rails, elevators, front loaders, backhoes, crânes, various scrapers and shovels, trucks, and throwing devices can be used. For example, vibratory conveyors can be used in various processes described herein. Vibratory conveyors are described in PCT/US2013/64289 filed October 10, 2013 the full disclosure of which is incorporated by reference herein.
[00178] Vibratory conveyors are particularly useful for spreading the material and producing a uniform layer on the conveyor trough surface. For example the initial feedstock can form a pile of material that can be at least four feet high (e.g., at least about 3 feet, at least about 2 feet, at least about 1 foot, at least about 6 inches, at least about 5 inches, at least about, 4 inches, at least about 3 inches, at least about 2 inches, at least about 1 inch, at least about */2 inch) and spans less than the width of the conveyor (e.g., less than about 10%, less than about 20%, less than about 30%, less than about 40%, less than about 50%, less than about 60%, less than about 70%, less than about 80%, less than about 90%, less than about 95%, less than about 99%). The vibratory conveyor can spread the material to span the entire width of the conveyor trough and hâve a uniform thickness, preferably as discussed above. In some cases, an additional spreading method can be useful. For example, a spreader such as a broadcast spreader, a drop spreader (e.g., a CHRISTY SPREADER™) or combinations thereof can be used to drop (e.g., place, pour, spill and/or sprinkle) the feedstock over a wide area. Optionally, the spreader can deliver the biomass as a wide shower or curtain onto the vibratory conveyor. Additionally, a second conveyor, upstream from the first conveyor (e.g., the first conveyor is used in the irradiation of the feedstock), can drop biomass onto the first conveyor, where the second conveyor can hâve a width transverse to the direction of conveying smaller than the first conveyor. In particular, when the second conveyor is a
vibratory conveyor, the feedstock is spread by the action of the second and first conveyor. In some optional embodiments, the second conveyor ends in a bias cross eut discharge (e.g., a bias eut with a ratio of 4:1) so that the material can be dropped as a wide curtain (e.g., wider than the width of the second conveyor) onto the first conveyor. The initial drop area of the biomass by the spreader (e.g., broadeast spreader, drop spreader, conveyor, or cross eut vibratory conveyor) can span the entire width of the first vibratory conveyor, or it can span part of this width. Once dropped onto the conveyor, the material is spread even more uniformly by the vibrations of the conveyor so that, preferably, the entire width of the conveyor is covered with a uniform layer of biomass. In some embodiments combinations of spreaders can be used. Some methods of spreading a feed stock are described in U.S. Patent No. 7,153,533, filed July 23, 2002 and published December 26, 2006, the entire disclosure of which is incorporated herein by reference.
[00179] Generally, it is preferred to convey the material as quickly as possible through an électron beam to maximize throughput. For example, the material can be conveyed at rates of at least 1 ft/min, e.g., at least 2 ft/min, at least 3 ft/min, at least 4 ft/min, at least 5 ft/min, at least 10 ft/min, at least 15 ft/min, at least 20 ft/min, at least 25 ft/min, at least 30 ft/min, at least 40 ft/min, at least 50 ft/min, at least 60 ft/min, at least 70 ft/min, at least 80 ft/min, at least 90 ft/min. The rate of conveying is related to the beam current and targeted irradiation dose, for example, for a % inch thick biomass spread over a 5.5 foot wide conveyor and 100 mA, the conveyor can move at about 20 ft/min to provide a useful irradiation dosage (e.g. about 10 Mrad for a single pass), at 50 mA the conveyor can move at about 10 ft/min to provide approximately the same irradiation dosage. [00180] The rate at which material can be conveyed dépends on the shape and mass of the material being conveyed, and the desired treatment. Flowing materials e.g., particulate materials, are particularly amenable to conveying with vibratory conveyors. Conveying speeds can, for example be, at least 100 lb/hr (e.g., at least 500 lb/hr, at least 1000 lb/hr, at least 2000 lb/hr, at least 3000 lb/hr, at least 4000 lb/hr, at least 5000 lb/hr, at least 10,000 lb/hr, at least 15, 000 lb/hr, or even at least 25,000 lb/hr). Some typical conveying speeds can be between about 1000 and 10,000 lb/hr, (e.g., between about 1000 lb/hr and 8000 lb/hr, between about 2000 and 7000 lb/hr, between about 2000 and 6000 lb/hr, between about 2000 and 50001b/hr, between about 2000 and 4500 lb/hr, between about 1500 and 5000 lb/hr, between about 3000 and 7000 lb/hr, between about 3000 and 6000 lb/hr, between about 4000 and 6000 lb/hr and between about 4000 and 5000 lb/hr). Typical conveying speeds dépend on the density of the material. For
example, for a biomass with a density of about 35 lb/ft3, and a conveying speed of about 5000 Ib/hr, the material is conveyed at a rate of about 143 ft3/hr, if the material is thick and is in a trough 5.5 ft wide, the material is conveyed at a rate of about 1250 ft/hr (about 21 ft/min). Rates of conveying the material can therefore vary greatly. Preferably, for example, a %” thick layer of biomass, is conveyed at speeds of between about 5 and 100 ft/min (e.g. between about 5 and 100 ft/min, between about 6 and 100 ft/min, between about 7 and 100 ft/min, between about 8 and 100 ft/min, between about 9 and 100 ft/min, between about 10 and 100 ft/min, between about 11 and 100 ft/min, between about 12 and 100 ft/min, between about 13 and 100 ft/min, between about 14 and 100 ft/min, between about 15 and 100 ft/min, between about 20 and 100 ft/min, between about 30 and 100 ft/min, between about 40 and 100 ft/min, between about 2 and 60 ft/min, between about 3 and 60 ft/min, between about 5 and 60 ft/min, between about 6 and 60 ft/min, between about 7 and 60 ft/min, between about 8 and 60 ft/min, between about 9 and 60 ft/min, between about 10 and 60 ft/min, between about 15 and 60 ft/min, between about 20 and 60 ft/min, between about 30 and 60 ft/min, between about 40 and 60 ft/min, between about 2 and 50 ft/min, between about 3 and 50 ft/min, between about 5 and 50 ft/min, between about 6 and 50 ft/min, between about 7 and 50 ft/min, between about 8 and 50 ft/min, between about 9 and 50 ft/min, between about 10 and 50 ft/min, between about 15 and 50 ft/min, between about 20 and 50 ft/min, between about 30 and 50 ft/min, between about 40 and 50 ft/min). It is préférable that the material be conveyed at a constant rate, for example, to help maintain a constant irradiation of the material as it passes under the électron beam (e.g., shower, field).
[00181] The vibratory conveyors described can include screens used for sieving and sorting materials. Port openings on the side or bottom of the troughs can be used for sorting, selecting or removing spécifie materials, for example, by size or shape. Some conveyors hâve counterbalances to reduce the dynamic forces on the support structure. Some vibratory conveyors are configured as spiral elevators, are designed to curve around surfaces and/or are designed to drop material from one conveyor to another (e.g., in a step, cascade or as a sériés of steps or a stair). Along with conveying materials conveyors can be used, by themselves or coupled with other equipment or Systems, for screening, separating, sorting, classifying, distributing, sizing, inspection, picking, métal removing, freezing, blending, mixing, orienting, heating, cooking, drying, dewatering, cleaning, washing, leaching, quenching, coating, de-dusting and/or feeding. The conveyors can also include covers (e.g., dust-tight covers), side discharge gates, bottom discharge gates, spécial liners (e.g., anti-stick, stainless steel, rubber, custom steal, and or
grooved), divided troughs, quench pools, screens, perforated plates, detectors (e.g., métal detectors), high température designs, food grade designs, heaters, dryers and or coolers. In addition, the trough can be of various shapes, for example, fiat bottomed, vee shaped bottom, flanged at the top, curved bottom, fiat with ridges in any direction, tubular, half pipe, covered or any combinations of these. In particular, the conveyors can be coupled with an irradiation Systems and/or equipment.
[00182] The conveyors (e.g., vibratory conveyor) can be made of corrosion résistant materials. The conveyors can utilize structural materials that include stainless steel (e.g., 304, 316 stainless steel, HASTELLOY® ALLOYS and INCONEL® Alloys). For example, HASTELLOY® Corrosion-Résistant alloys from Hynes (Kokomo, Indiana, USA) such as HASTELLOY® B-3® ALLOY, HASTELLOY® HYBRDD-BC1® ALLOY, HASTELLOY® C-4 ALLOY, HASTELLOY® C-22® ALLOY, HASTELLOY® C-22HS® ALLOY, HASTELLOY® C-276 ALLOY, HASTELLOY® C-2000® ALLOY, HASTELLOY® G-30® ALLOY, HASTELLOY® G-35® ALLOY, HASTELLOY® N ALLOY and HASTELLOY® ULTIMET® alloy.
[00183] The vibratory conveyors can include non-stick release coatings, for example, TUFFLON™ (Dupont, Delaware, USA). The vibratory conveyors can also include corrosion résistant coatings. For example, coatings that can be supplied from Métal Coatings Corp (Houston, Texas, USA) and others such as Fluoropolymer, XYLAN®, Molybdenum Disulfide, Epoxy Phenolic, Phosphate- ferrous métal coating, Polyuréthane- high gloss topcoat for epoxy, inorganic zinc, Poly Tetrafluoro ethylene, PPS/RYTON®, fluorinated ethylene propylene, PVDF/DYKOR®, ECTFE/HALAR® and Ceramic Epoxy Coating. The coatings can improve résistance to process gases (e.g., ozone), chemical corrosion, pitting corrosion, galling corrosion and oxidation.
[00184] Optionally, in addition to the conveying Systems described herein, one or more other conveying Systems can be enclosed. When using an enclosure, the enclosed conveyor can also be purged with an inert gas so as to maintain an atmosphère at a reduced oxygen level. Keeping oxygen levels low avoids the formation of ozone which in some instances is undesirable due to its reactive and toxic nature. For example, the oxygen can be less than about 20% (e.g., less than about 10%, less than about 1%, less than about 0.1%, less than about 0.01%, or even less than about 0.001% oxygen). Purging can be done with an inert gas including, but not limited to, nitrogen, argon, hélium or carbon dioxide. This can be supplied, for example, from a boil off of a liquid source (e.g., liquid nitrogen or hélium), generated or separated from air in situ, or supplied from tanks. The inert gas can be recirculated and any residual oxygen can be
Y
removed using a catalyst, such as a copper catalyst bed. Altematively, combinations of purging, recirculating and oxygen removal can be done to keep the oxygen levels low. [00185] The enclosed conveyor can also be purged with a reactive gas that can react with the biomass. This can be done before, during or after the irradiation process. The reactive gas can be, but is not limited to, nitrous oxide, ammonia, oxygen, ozone, hydrocarbons, aromatic compounds, amides, peroxides, azides, halides, oxyhalides, phosphides, phosphines, arsines, sulfides, thiols, boranes and/or hydrides. The reactive gas can be activated in the enclosure, e.g., by irradiation (e.g., électron beam, UV irradiation, microwave irradiation, heating, IR radiation), so that it reacts with the biomass. The biomass itself can be activated, for example by irradiation. Preferably the biomass is activated by the électron beam, to produce radicals which then react with the activated or unactivated reactive gas, e.g., by radical coupling or quenching.
[00186] Purging gases supplied to an enclosed conveyor can also be cooled, for example below about 25°C, below about 0°C, below about -40°C, below about -80°C, below about -120°C. For example, the gas can be boiled off from a compressed gas such as liquid nitrogen or sublimed from solid carbon dioxide. As an alternative example, the gas can be cooled by a chiller or part of or the entire conveyor can be cooled.
OTHER EMBODIMENTS [00187] Any material, processes or processed materials discussed herein can be used to make products and/or intermediates such as composites, fillers, binders, plastic additives, adsorbents and controlled release agents. The methods can include densification, for example, by applying pressure and heat to the materials. For example composites can be made by combining fibrous materials with a resin or polymer. For example, radiation cross-linkable resin, e.g., a thermoplastic resin can be combined with a fibrous material to provide a fibrous material/cross-linkable resin combination. Such materials can be, for example, useful as building materials, protective sheets, containers and other structural materials (e.g., molded and/or extruded products). Absorbents can be, for example, in the form of pellets, chips, fibers and/or sheets. Adsorbents can be used, for example, as pet bedding, packaging material or in pollution control Systems. Controlled release matrices can also be the form of, for example, pellets, chips, fibers and or sheets. The controlled release matrices can, for example, be used to release drugs, biocides, fragrances. For example, composites, absorbents and control release agents and their uses are described in International Serial No. PCT/US2006/010648, filed
March 23, 2006, and U.S. Patent No. 8,074,910 filed November 22, 2011, the entire disclosures of which are herein incorporated by reference.
[00188] In some instances the biomass material is treated at a first level to reduce recalcitrance, e.g., utilizing accelerated électrons, to selectively release one or more sugars (e.g., xylose). The biomass can then be treated to a second level to release one or more other sugars (e.g., glucose). Optionally, the biomass can be dried between treatments. The treatments can include applying chemical and biochemical treatments to release the sugars. For example, a biomass material can be treated to a level of less than about 20 Mrad (e.g., less than about 15 Mrad, less than about 10 Mrad, less than about 5 Mrad, less than about 2 Mrad) and then treated with a solution of sulfuric acid, containing less than 10% sulfuric acid (e.g., less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.75%, less than about 0.50 %, less than about 0.25%) to release xylose. Xylose, for example, that is released into solution, can be separated from solids and optionally the solids washed with a solvent/solution (e.g., with water and/or acidified water). Optionally, the solids can be dried, for example in air and/or under vacuum optionally with heating (e.g., below about 150 deg C, below about 120 deg C) to a water content below about 25 wt.% (below about 20 wt.%, below about 15 wt.%, below about 10 wt.%, below about 5 wt.%). The solids can then be treated with a level of less than about 30 Mrad (e.g., less than about 25 Mrad, less than about 20 Mrad, less than about 15 Mrad, less than about 10 Mrad, less than about 5 Mrad, less than about 1 Mrad or even not at ail) and then treated with an enzyme (e.g., a cellulase) to release glucose. The glucose (e.g., glucose in solution) can be separated from the remaining solids. The solids can then be further processed, for example, utilized to make energy or other products (e.g., lignin derived products).
FLAVORS, FRAGRANCES AND COLORS [00189] Any of the products and/or intermediates described herein, for example, produced by the processes, Systems and/or equipment described herein, can be combined with flavors, fragrances, colorants and/or mixtures of these. For example, any one or more of (optionally along with flavors, fragrances and/or colorants) sugars, organic acids, fuels, polyols, such as sugar alcohols, biomass, fibers and composites can be combined with (e.g., formulated, mixed or reacted) or used to make other products. For example, one or more such product can be used to make soaps, détergents, candies,
dnnks (e.g., cola, wme, beer, liquors such as gin or vodka, sports dnnks, coffees, teas), syrups, pharmaceuticals, adhesives, sheets (e.g., woven, none woven, filters, tissues) and/or composites (e.g., boards). For example, one or more such product can be combined with herbs, flowers, petals, spices, vitamins, potpourri, or candies. For example, the formulated, mixed or reacted combinations can hâve flavors/fragrances of grapefruit, orange, apple, raspberry, banana, lettuce, celery, cinnamon, chocolaté, vanilla, peppermint, mint, onion, garlic, pepper, saffron, ginger, milk, wine, beer, tea, lean beef, fish, clams, olive oil, coconut fat, pork fat, butter fat, beef bouillon, legume, potatoes, marmalade, ham, coffee and cheeses.
[00190] Flavors, fragrances and colorants can be added in any amount, such as between about 0.001 wt.% to about 30 wt.%, e.g., between about 0.01 to about 20, between about 0.05 to about 10, or between about 0.1 wt.% to about 5 wt.%. These can be formulated, mixed and/or reacted (e.g., with any one of more product or intermediate described herein) by any means and in any order or sequence (e.g., agitated, mixed, emulsified, gelled, infused, heated, sonicated, and/or suspended). Fillers, binders, emulsifier, antioxidants can also be utilized, for example, protein gels, starches and silica.
[00191] In one embodiment the flavors, fragrances and colorants can be added to the biomass immediately after the biomass is irradiated such that the reactive sites created by the irradiation may react with reactive compatible sites of the flavors, fragrances, and colorants.
[00192] The flavors, fragrances and colorants can be natural and/or synthetic materials. These materials can be one or more of a compound, a composition or mixtures of these (e.g., a formulated or natural composition of several compounds). Optionally, the flavors, fragrances, antioxidants and colorants can be derived biologically, for example, from a fermentation process (e.g., fermentation of saccharified materials as described herein). Altematively, or additionally these flavors, fragrances and colorants can be harvested from a whole organism (e.g., plant, fungus, animal, bacteria or yeast) or a part of an organism. The organism can be collected and/or extracted to provide color, flavors, fragrances and/or antioxidant by any means including utilizing the methods, Systems and equipment described herein, hot water extraction, supercritical fluid extraction, chemical extraction (e.g., solvent or reactive extraction including acids and bases), mechanical extraction (e.g., pressing, comminuting, filtering), utilizing an enzyme, utilizing a bacteria such as to break down a starting material, and combinations of these methods. The compounds can be derived by a chemical reaction, for example,
the combination of a sugar (e.g., as produced as described herein) with an amino acid (Maillard reaction). The flavor, fragrance, antioxidant and/or colorant can be an intermediate and/or product produced by the methods, equipment or Systems described herein, for example, and ester and a lignin derived product.
[00193] Some examples of flavor, fragrances or colorants are polyphenols. Polyphenols are pigments responsible for the red, purple and blue colorants of many fruits, vegetables, cereal grains, and flowers. Polyphenols also can hâve antioxidant properties and often hâve a bitter taste. The antioxidant properties make these important preservatives. On class of polyphenols are the flavonoids, such as Anthocyanidines, flavanonols, flavan-3-ols, flavanones and flavanonols. Other phenolic compounds that can be used include phenolic acids and their esters, such as chlorogenic acid and polymeric tannins.
[00194] Among the colorants inorganic compounds, minerais or organic compounds can be used, for example titanium dioxide, zinc oxide, aluminum oxide, cadmium yellow (E.g., CdS), cadmium orange (e.g., CdS with some Se), alizarin crimson (e.g., synthetic or non-synthetic rose madder), ultramarine (e.g., synthetic ultramarine, natural ultramarine, synthetic ultramarine violet ), cobalt blue, cobalt yellow, cobalt green, viridian (e.g., hydrated chromium(III)oxide), chalcophylite, conichalcite, comubite, cornwallite and liroconite. Black pigments such as carbon black and self-dispersed blacks may be used.
[00195] Some flavors and fragrances that can be utilized include ACALEA TBHQ, ACET C-6, ALLYL AMYL GLYCOLATE, ALPHA TERPENEOL, AMBRETTOLIDE, AMBRINOL 95, ANDRANE, APHERMATE, APPLELIDE, BACDANOL®, BERGAMAL, BETA IONONE EPOXIDE, BETA NAPHTHYLISO-BUTYL ETHER, BICYCLONONALACTONE, BORNAFIX®, CANTHOXAL, CASHMERAN®, CASHMERAN® VELVET, CASSIFFIX®, CEDRAFIX, CEDRAMBER®, CEDRYL ACETATE, CELESTOLIDE, CINNAMALVA, CITRAL DIMETHYL ACETATE, CITROLATE™, CITRONELLOL 700, CITRONELLOL 950, CITRONELLOL COEUR, CITRONELLYL ACETATE, CITRONELLYL ACETATE PURE, CITRONELLYL FORMATE, CLARYCET, CLONAL, CONIFERAN, CONIFERAN PURE, CORTEX ALDEHYDE 50% PEOMOSA, CYCLABUTE, CYCLACET®, CYCLAPROP®, CYCLEMAX™, CYCLOHEXYL ETHYL ACETATE, DAMASCOL, DELTA DAMASCONE, DIHYDRO CYCLACET, DIHYDRO MYRCENOL, DIHYDRO TERPINEOL, DIHYDRO TERPINYL ACETATE, DIMETHYL CYCLORMOL, DIMETHYL OCTANOL PQ, DIMYRCETOL, DIOLA, DIPENTENE,
DULCINYL® RECRYSTALLIZED, ETHYL-3-PHENYL GLYCIDATE, FLEURAMONE, FLEURANIL, FLORAL SUPER, FLORALOZONE, FLORIFFOL, FRAISTONE, FRUCTONE, GALAXOLIDE® 50, GALAXOLIDE® 50 BB, GALAXOLIDE® 50 IPM, GALAXOLIDE® UNDILUTED, GALBASCONE, GERALDEHYDE, GERANIOL 5020, GERANIOL 600 TYPE, GERANIOL 950, GERANIOL 980 (PURE), GERANIOL CFT COEUR, GERANIOL COEUR, GERANYL ACETATE COEUR, GERANYL ACETATE, PURE, GERANYL FORMATE, GRISALVA, GUAIYL ACETATE, HELIONAL™, HERBAC, HERBALIME™, HEXADECANOLIDE, HEXALON, HEXENYL SALICYLATE CIS 3-, HYACINTH BODY, HYACINTH BODY NO. 3, HYDRATROPIC ALDEHYDE.DMA, HYDROXYOL, INDOLAROME, INTRELEVEN ALDEHYDE, INTRELEVEN ALDEHYDE SPECIAL, IONONE ALPHA, IONONE BETA, ISO CYCLO CITRAL, ISO CYCLO GERANIOL, ISO E SUPER®, ISOBUTYL QUINOLINE, JASMAL, JESSEMAL®, KHARISMAL®, KHARISMAL® SUPER, KHUSINIL, KOAVONE®, KOHINOOL®, LIFFAROME™, LIMOXAL, LINDENOL™, LYRAL®, LYRAME SUPER, MANDARIN ALD 10% TRI ETH, CITR, MARITIMA, MCK CHINESE, MEIJIFF™, MELAFLEUR, MELOZONE, METHYL ANTHRANILATE, METHYL IONONE ALPHA EXTRA, METHYL IONONE GAMMA A, METHYL IONONE GAMMA COEUR, METHYL IONONE GAMMA PURE, METHYL LAVENDER KETONE, MONT A VERDI®, MUGUESIA, MUGUET ALDEHYDE 50, MUSKZ4, MYRAC ALDEHYDE, MYRCENYL ACETATE, NECTARATE™, NEROL 900, NERYL ACETATE, OCIMENE, OCTACETAL, ORANGE FLOWER ETHER, ORIVONE, ORRINIFF 25%, OXASPIRANE, OZOFLEUR, PAMPLEFLEUR®, PEOMOSA, PHENOXANOL®, PICONIA, PRECYCLEMONE B, PRENYL ACETATE, PRISMANTOL, RESEDA BODY, ROSALVA, ROSAMUSK, SANJINOL, SANTALIFF™, SYVERTAL, TERPINEOL,TERPINOLENE 20, TERPINOLENE 90 PQ, TERPINOLENE RECT., TERPINYL ACETATE, TERPINYL ACETATE JAX, TETRAHYDRO, MUGUOL®, TETRAHYDRO MYRCENOL, TETRAMERAN, TIMBERSILK™, TOBACAROL, TRIMOFIX® O TT, TRIPLAL®, TRISAMBER®, VANORIS, VERDOX™, VERDOX™ HC, VERTENEX®, VERTENEX® HC, VERTOFIX® COEUR, VERTOLIFF, VERTOLIFF ISO, VIOLIFF, VIVALDIE, ZENOLIDE, ABS INDIA 75 PCT MIGLYOL, ABS MOROCCO 50 PCT DPG, ABS MOROCCO 50 PCT TEC, ABSOLUTE FRENCH, ABSOLUTE INDIA, ABSOLUTE MD 50 PCT BB, ABSOLUTE MOROCCO, CONCENTRATE PG, TINCTURE 20 PCT, AMBERGRIS,
AMBRETTE ABSOLUTE, AMBRETTE SEED OIL, ARMOISE OIL 70 PCT THUYONE, BASIL ABSOLUTE GRAND VERT, BASIL GRAND VERT ABS MD, BASIL OIL GRAND VERT, BASIL OEL VER VEINA, BASIL OIL VIETNAM, BAY OIL TERPENELESS, BEESWAX ABS N G, BEESWAX ABSOLUTE, BENZOIN RESINOID SIAM, BENZOIN RESINOID SIAM 50 PCT DPG, BENZOIN RESINOID SIAM 50 PCT PG, BENZOIN RESINOID SIAM 70.5 PCT TEC, BLACKCURRANT BUD ABS 65 PCT PG, BLACKCURRANT BUD ABS MD 37 PCT TEC, BLACKCURRANT BUD ABS MIGLYOL, BLACKCURRANT BUD ABSOLUTE BURGUNDY, BOIS DE ROSE OIL, BRAN ABSOLUTE, BRAN RESINOID, BROOM ABSOLUTE ITALY, CARDAMOM GUATEMALA CO2 EXTRACT, CARDAMOM OIL GUATEMALA, CARDAMOM OIL INDIA, CARROT HEART, CASSIE ABSOLUTE EGYPT, CASSIE ABSOLUTE MD 50 PCT IPM, CASTOREUM ABS 90 PCT TEC, CASTOREUM ABS C 50 PCT MIGLYOL, CASTOREUM ABSOLUTE, CASTOREUM RESINOID, CASTOREUM RESINOID 50 PCT DPG, CEDROL CEDRENE, CEDRUS ATLANTICA OIL REDIST, CHAMOMILE OIL ROMAN, CHAMOMILE OIL WELD, CHAMOMILE OIL WILD LOW LIMONENE, CINNAMON BARK OIL CEYLAN, CISTE ABSOLUTE, CISTE ABSOLUTE COLORLESS, CITRONELLA OEL ASIA IRON FREE, CIVET ABS 75 PCT PG, CIVET ABSOLUTE, CIVET TINCTURE 10 PCT, CLARY SAGE ABS FRENCH DECOL, CLARY SAGE ABSOLUTE FRENCH, CLARY SAGE C’LESS 50 PCT PG, CLARY SAGE OIL FRENCH, COPAIBA BALSAM, COPAIBA BALSAM OIL, CORIANDER SEED OIL, CYPRESS OIL, CYPRESS OIL ORGANIC, DAVANA OIL, GALBANOL, GALBANUM ABSOLUTE COLORLESS, GALBANUM OIL, GALBANUM RESINOID, GALBANUM RESINOID 50 PCT DPG, GALBANUM RESINOID HERCOLYN BHT, GALBANUM RESINOID TEC BHT, GENTIANE ABSOLUTE MD 20 PCT BB, GENTIANE CONCRETE, GERANIUM ABS EGYPT MD, GERANIUM ABSOLUTE EGYPT, GERANIUM OIL CHINA, GERANIUM OIL EGYPT, GINGER OIL 624, GINGER OIL RECTIFIED SOLUBLE, GUAIACWOOD HEART, HAY ABS MD 50 PCT BB, HAY ABSOLUTE, HA Y ABSOLUTE MD 50 PCT TEC, HEALINGWOOD, HYSSOP OIL ORGANIC, IMMORTELLE ABS YUGO MD 50 PCT TEC, IMMORTELLE ABSOLUTE SPAIN, IMMORTELLE ABSOLUTE YUGO, JASMIN ABS INDIA MD, JASMIN ABSOLUTE EGYPT, JASMIN ABSOLUTE INDIA, ASMIN ABSOLUTE MOROCCO, JASMIN ABSOLUTE SAMBAC, JONQUILLE ABS MD 20 PCT BB, JONQUILLE ABSOLUTE France, JUNIPER BERRY OEL FLG, JUNIPER BERRY OIL RECTIFIED SOLUBLE,
LABDANUM RESINOID 50 PCT TEC, LABDANUM RESINOID BB, LABDANUM RESINOID MD, LABDANUM RESINOID MD 50 PCT BB, LAVANDIN ABSOLUTE H, LAVANDIN ABSOLUTE MD, LAVANDIN OIL ABRIAL ORGANIC, LAVANDIN OIL GROSSO ORGANIC, LAVANDIN OIL SUPER, LAVENDER ABSOLUTE H, LAVENDER ABSOLUTE MD, LAVENDER OIL COUMARIN FREE, LAVENDER OIL COUMARIN FREE ORGANIC, LAVENDER OIL MAILLETTE ORGANIC, LAVENDER OEL MT, MACE ABSOLUTE BB, MAGNOLIA FLOWER OIL LOW METHYL EUGENOL, MAGNOLIA FLOWER OIL, MAGNOLIA FLOWER OIL MD, MAGNOLIA LEAF OIL, MANDARIN OEL MD, MANDARIN OIL MD BHT, MATE ABSOLUTE BB, MOSS TREE ABSOLUTE MD TEX IFRA 43, MOSS-OAK ABS MD TEC IFRA 43, MOSS-OAK ABSOLUTE IFRA 43, MOSS-TREE ABSOLUTE MD IPM IFRA 43, MYRRH RESINOID BB, MYRRH RESINOID MD, MYRRH RESINOID TEC, MYRTLE OIL IRON FREE, MYRTLE OIL TUNISIA RECTIFIED, NARCISSE ABS MD 20 PCT BB, NARCISSE ABSOLUTE FRENCH, NEROLI OIL TUNISIA, NUTMEG OIL TERPENELESS, OEILLET ABSOLUTE, OLIBANUM RESINOID, OLIBANUM RESINOID BB, OLIBANUM RESINOID DPG, OLIBANUM RESINOID EXTRA 50 PCT DPG, OLIBANUM RESINOID MD, OLIBANUM RESINOID MD 50 PCT DPG, OLIBANUM RESINOID TEC, OPOPONAX RESINOID TEC, ORANGE BIGARADE OIL MD BHT, ORANGE BIGARADE OIL MD SCFC, ORANGE FLOWER ABSOLUTE TUNISIA, ORANGE FLOWER WATER ABSOLUTE TUNISIA, ORANGE LEAF ABSOLUTE, ORANGE LEAF WATER ABSOLUTE TUNISIA, ORRIS ABSOLUTE ITALY, ORRIS CONCRETE 15 PCT IRONE, ORRIS CONCRETE 8 PCT IRONE, ORRIS NATURAL 15 PCT IRONE 4095C, ORRIS NATURAL 8 PCT ERONE 2942C, ORRIS RESINOID, OSMANTHUS ABSOLUTE, OSMANTHUS ABSOLUTE MD 50 PCT BB, PATCHOULI HEART N°3, PATCHOULI OIL INDONESIA, PATCHOULI OIL INDONESIA IRON FREE, PATCHOULI OEL INDONESIA MD, PATCHOULI OIL REDIST, PENNYROYAL HEART, PEPPERMINT ABSOLUTE MD, PETITGRAIN BIGARADE OIL TUNISIA, PETITGRAIN CITRONNIER OIL, PETITGRAIN OIL PARAGUAY TERPENELESS, PETITGRAIN OIL TERPENELESS STAB, PIMENTO BERRY OIL, PIMENTO LEAF OIL, RHODINOL EX GERANIUM CHINA, ROSE ABS BULGARIAN LOW METHYL EUGENOL, ROSE ABS MOROCCO LOW METHYL EUGENOL, ROSE ABS TURKISH LOW METHYL EUGENOL, ROSE ABSOLUTE, ROSE ABSOLUTE BULGARIAN, ROSE ABSOLUTE DAMASCENA, ROSE ABSOLUTE MD, ROSE
ABSOLUTE MOROCCO, ROSE ABSOLUTE TURKISH, ROSE OIL BULGARIAN, ROSE OIL DAMASCENA LOW METHYL EUGENOL, ROSE OIL TURKISH, ROSEMARY OIL CAMPHOR ORGANIC, ROSEMARY OIL TUNISIA, SANDALWOOD OIL INDIA, SANDALWOOD OIL INDIA RECTIFIED, SANTALOL, SCHINUS MOLLE OIL, ST JOHN BREAD TINCTURE 10 PCT, STYRAX RESINOID, STYRAX RESINOID, TAGETE OIL, TEA TREE HEART, TONKA BEAN ABS 50 PCT SOLVENTS, TONKA BEAN ABSOLUTE, TUBEROSE ABSOLUTE INDIA, VETIVER HEART EXTRA, VETIVER OIL HAITI, VETIVER OIL HAITI MD, VETIVER OIL JAVA, VETIVER OIL JAVA MD, VIOLET LEAF ABSOLUTE EGYPT, VIOLET LEAF ABSOLUTE EGYPT DECOL, VIOLET LEAF ABSOLUTE FRENCH, VIOLET LEAF ABSOLUTE MD 50 PCT BB, WORMWOOD OIL TERPENELESS, YLANG EXTRA OIL, YLANG ΠΙ OIL and combinations of these.
[00196] The colorants can be among those listed in the Color Index International by the Society of Dyers and Colourists. Colorants include dyes and pigments and include those commonly used for coloring textiles, paints, inks and inkjet inks. Some colorants that can be utilized include carotenoids, arylide yellows, diarylide yellows, B-naphthols, naphthols, benzimidazolones, disazo condensation pigments, pyrazolones, nickel azo yellow, phthalocyanines, quinacridones, perylenes and perinones, isoindolinone and isoindoline pigments, triarylcarbonium pigments, diketopyrrolo-pyrrole pigments, thioindigoids. Cartenoids include, e.g., alpha-carotene, beta-carotene, gamma-carotene, lycopene, lutein and astaxanthinAnnatto extract, Dehydrated beets (beet powder), Canthaxanthin, Caramel, P-Apo-8'-carotenal, Cochineal extract, Carminé, Sodium copper chlorophyllin, Toasted partially defatted cooked cottonseed flour, Ferrous gluconate, Ferrous lactate, Grape color extract, Grape skin extract (enocianina), Carrot oil, Paprika, Paprika oleoresin, Mica-based pearlescent pigments, Riboflavin, Saffron, Titanium dioxide, Tomato lycopene extract; tomato lycopene concentrate, Turmeric, Turmeric oleoresin, FD&C Blue No. 1, FD&C Blue No. 2, FD&C Green No. 3, Orange B, Citrus Red No. 2, FD&C Red No. 3, FD&C Red No. 40, FD&C Yellow No. 5, FD&C Yellow No. 6, Alumina (dried aluminum hydroxide), Calcium carbonate, Potassium sodium copper chlorophyllin (chlorophyllin-copper complex), Dihydroxyacetone, Bismuth oxychloride, Ferrie ammonium ferrocyanide, Ferrie ferrocyanide, Chromium hydroxide green, Chromium oxide greens, Guanine, Pyrophyllite, Talc, Aluminum powder, Bronze powder, Copper powder, Zinc oxide, D&C Blue No. 4, D&C Green No. 5, D&C Green No. 6, D&C Green No. 8, D&C Orange No. 4, D&C Orange No. 5, D&C
Orange No. 10, D&C Orange No. 11, D&C Red No. 4, D&C Red No. 6, D&C Red No. 7, D&C Red No. 17, D&C Red No. 21, D&C Red No. 22, D&C Red No. 27, D&C Red No. 28, D&C Red No. 30, D&C Red No. 31, D&C Red No. 33, D&C Red No. 34, D&C Red No. 36, D&C Red No. 39, D&C Violet No. 2, D&C Yellow No. 7, Ext. D&C Yellow No. 7, D&C Yellow No. 8, D&C Yellow No. 10, D&C Yellow No. 11, D&C Black No. 2, D&C Black No. 3 (3), D&C Brown No. 1, Ext. D&C, Chromium-cobaltaluminum oxide, Ferrie ammonium citrate, Pyrogallol, Logwood extract, 1,4-Bis[(2hydroxy-ethyl)amino]-9,10-anthracenedione bis(2-propenoic)ester copolymers, 1,4-Bis [(2-methylphenyl)amino] -9,10-anthracenedione, 1,4-Bis[4- (2-methacryloxyethyl) phenylamino] anthraquinone copolymers, Carbazole violet, Chlorophyllin-copper complex, Chromium-cobalt-aluminum oxide, C.I. Vat Orange 1, 2-[[2,5-Diethoxy- 4-[(4methylphenyl)thiol] phenyl]azo] -1,3,5-benzenetriol, 16,23-Dihydrodinaphtho [2,3a:2',3'-i] naphth [2',3':6,7] indolo [2,3-c] carbazole- 5,10,15,17,22,24-hexone, N,N'-(9,10Dihydro- 9,10-dioxo- 1,5-anthracenediyl) bisbenzamide, 7,16-Dichloro- 6,15-dihydro5,9,14,18-anthrazinetetrone, 16,17-Dimethoxydinaphtho (l,2,3-cd:3',2',r-lm) perylene5,10-dione, Poly(hydroxyethyl méthacrylate) -dye copolymers(3), Reactive Black 5, Reactive Blue 21, Reactive Orange 78, Reactive Yellow 15, Reactive Blue No. 19, Reactive Blue No. 4, C.I. Reactive Red 11, C.I. Reactive Yellow 86, C.I. Reactive Blue 163, C.I. Reactive Red 180,4-[(2,4-dimethylphenyl)azo]- 2,4-dihydro- 5-methyl-2phenyl- 3H-pyrazol-3-one (solvent Yellow 18), 6-Ethoxy-2- (6-ethoxy-3-oxobenzo[b] thien-2(3H)- ylidene) benzo[b]thiophen- 3(2H)-one, Phthalocyanine green, Vinyl alcohol/methyl methacrylate-dye reaction products, C.I. Reactive Red 180, C.I. Reactive Black 5, C.I. Reactive Orange 78, C.I. Reactive Yellow 15, C.I. Reactive Blue 21, Disodium l-amino-4-[[4-[(2-bromo-l-oxoallyl)amino]-2-sulphonatophenyl]amino]-9,10dihydro-9,10-dioxoanthracene-2-sulphonate (Reactive Blue 69), D&C Blue No. 9, [Phthalocyaninato(2-)] copper and mixtures of these.
EXAMPLES [00197] Concentrations were determined by HPLC in aqueous diluted and filtered solutions with appropriate standards.
Saccharification [00198] A cylindrical tank with a diameter of 32 Inches, 64 Inches in height and fit with ASME dished heads (top and bottom) was used in the saccharification. The tank
was also equipped with a hydrofoil mixing blade 16” wide. Heating was provided by flowing hot water through a half pipe jacket surrounding the tank.
[00199] The tank was charged with 200 Kg water, 80 Kg of biomass, and 18 Kg of Duet™ Cellulase enzyme. Biomass was com cob that had been hammer milled and screened to a size of between 40 and 10 mesh. The biomass was irradiated with an électron beam to a total dosage of 35 Mrad. The pH of the mixture was adjusted and maintained automatically throughout the saccharification at 4.8 using Ca(OH)2. This combination was heated to 53 °C, stirred at 180 rpm (1.8 Amp at 460V) for about 24 hours after which the saccharification was considered completed.
A portion of this material was screened through a 20 mesh screen and the solution stored in an 8 gai carboy at 4 °C.
Biomass Produced Ethanol and Xylose Stream [00200] About 400 mL of the saccharified material was decanted into a IL New Brunswick BioFlow 115 Bioreactor. The Material was aerated and heated to 30 °C prior to inoculation. Stirring was set at 50 rpm. The pH was measured at 5.2, which is acceptable for fermentation so it was not adjusted. Aération was discontinued and the contents of the bioreactor were inoculated with 5 mg of Thermosacc Dry Yeast (Lallemand, Inc.). Fermentation was allowed to proceed for about 24 hours.
[00201] After fermentation the glucose concentration was below the détection limit, the éthanol concentration was about 25 g/L, and the xylose concentration was 30 g/L.
Purification of Ethanol and Xylose Stream using Desalination Electrodialvsis [00202] Four liters of post fermentation solution was concentrated under vacuo to about 11Z3L. The concentrated, éthanol free, solution was then diluted back to its original volume with methanol. Addition of the methanol caused immédiate formation and précipitation of solids. It was found that the precipitate can be effectively removed by centrifugation or filtration.
[00203] The solid free solution was then treated with 5% (by weight/volume) activated carbon to decolorize the solution. The carbon was removed by filtration and the filtrate was then concentrated in vacuo to remove methanol. The solution was subsequently diluted to its original volume with de-ionized water.
[00204] Two Liters of the decolorized solution was then subjected to electrodialysis.
The voltage across a stack of 20 membranes was 40 V. The conductivity, température and pH were measured. FIG. 3 is a plot of the conductivity vs time in the dilute streams.
The experiment lasted for 71 min wherein the conductivity decreased from 7830 pS/cm
to 9 pS/cm, the température increased from to 25 deg. C to 33 deg. C and the measured pH decreased from about 4.8 to 4.0.
[00205] Elemental analysis (ICP) showed the improvement in reducing the ions throughout the processing. Elemental analysis was done in duplicate or triplicate.
Table 1: Post Fermentation Elemental Analysis.
| Element | Run 1 (PPM) | Run 2 (PPM) | Average Conc. (PPM) |
| P | 200.487 | 207.757 | 204.1 |
| K | 2575.76 | 2544.59 | 2560.2 |
| Mg | 659.075 | 646.172 | 652.6 |
| Na | 117.657 | 122.913 | 120.3 |
| Ca | 960.487 | 957.068 | 958.8 |
| S | 104.053 | 100.836 | 102.4 |
Table 2; Elemental Analysis post Methanol Treatment
| Element | Run 1 (PPM) | Run 2 (PPM) | Average Conc. (PPM) |
| P | 19.8376 | 17.6737 | 18.8 |
| K | 926.542 | 1020.84 | 973.7 |
| Mg | 228.527 | 249.227 | 238.9 |
| Na | 53.6198 | 51.8139 | 52.7 |
| Ca | 175.527 | 192.593 | 184.1 |
| S | 29.342 | 24.8865 | 27.1 |
Table 3: Elemental Analysis Post Electrodialvsis Treatment.
| Element | Run 1 (PPM) | Run 2 (PPM) | Run 3 (PPM) | Average Conc. (PPM) |
| Mn | 0.330925 | 0.291988 | 0.276951 | 0.3 |
| Al | 0.563302 | 0.52201 | 0.57087 | 0.6 |
| Zn | 0.577498 | 0.608856 | 0.610446 | 0.6 |
| Si | 5.65798 | 5.63068 | 5.77249 | 5.7 |
| Fe | 0.601713 | 0.564221 | 0.548226 | 0.6 |
| P | 2.9462 | 1.98296 | 2.30069 | 2.4 |
| K | 2.85595 | 1.99511 | 0.614186 | 1.8 |
| Mg | 0.606541 | 0.548299 | 0.564928 | 0.6 |
| Na | 1.00027 | 0.82686 | 1.00563 | 0.9 |
| Ca | 1.78259 | 0.894467 | 2.54184 | 1.7 |
| S | 7.65224 | 7.32835 | 7.04753 | 7.3 |
[00206] Throughout the post fermentation processing the Xylose concentration remained constant at about 30 g/L with no apparent dégradation.
Biomass Produced L-lactic acid and Xylose Stream with Lactobacillus rhamnosus [00207] Saccharified biomass made utilizing similar steps as described above was used as the sugar source to produce an L-lactic acid/xylose stream.
[00208] The glucose to L-Lactic acid fermenting organisai Lactobacillus rhamnosus NRRL B-445 was grown in 25 mL of MRS medium (BD Diagnostic Systems No.: 288130) from 250 uL freezer stocks. The culture was incubated ovemight in a shaker incubator at 37 °C and 150-200rpm.
[00209] Fermentation to produce the lactic acid was conducted in a bioreactor equipped with stirring paddle, heating mantel, stirring impellors, pH monitoring probes and température monitoring thermocouples.
[00210] The production medium for an experiment used 11 L of saccharified biomass, 22g of yeast extract, 1.6 mL of antifoam AFE-0010. The media was heated to 70 °C for 1 hour and then cooled to 37 °C. The pH of the media was raised to 6.5 using 12.5N NaOH solution. The media was then inoculated with 1% (110 mL) of the Lactobacillus rhamnosus. Fermentation was allowed to proceed at 37 °C while the solution was stirred at 200 rpm and the pH maintained above 6.5. Glucose was completely consumed by 48 hours. The product is L-lactic acid as the sodium sait. Xylose produced during saccharification was not consumed; it was essentially unconverted during this step.
Biomass Produced D-lactic acid and Xylose Stream with Lactobacillus coryniformis [00211] Saccharified biomass made utilizing similar steps as described above was used as the sugar source to produce an L-lactic acid xylose stream.
[00212] The glucose to D-Lactic acid fermenting organisai Lactobacillus coryniformis subspecies torquens B-4390 was grown in 25 mL of MRS medium (BD Diagnostic Systems No.: 288130) from 250 pL freezer stocks. The culture was incubated ovemight at 37 °C without agitation.
[00213] The production medium for an experiment used 644 mL of saccharified biomass, 5 g/L of tryptone, and 100 pL of antifoam AFE-0010. The media was heated to 70 °C for 1 hour and then cooled to 37 °C. The pH was raised to 6.5 using 12.5N NaOH solution and maintained thereafter using the same base solution. The media was inoculated with 1% of the B-4390 and the fermentation wall allowed to proceed at 37 °C while the media was stirred at 200 rpm and the pH maintained at about 6.5. Glucose consumption was complété in 144 hours. The product is D-lactic acid as the sodium sait.
Xylose produced during saccharification was not consumed; it was essentially unconverted during this step.
[00214] .
Processing of Sodium Lactate solution [00215] Both the D-lactic acid and L-lactic acid derived sodium lactate were decolorized as described here. Fermentations were run repeatedly to provide larger quantities of material and facilitate the decolorization.
[00216] Thirty liters of fermentation medium containing sodium lactate prepared by fermentation as described above were centrifuged at 4200 rpm for 60 minutes. The supernatant was filtered through a 0.22 micron cartridge filter producing 26.5 L of filtrate. Nineteen liters of the filtrate were percolated through a column containing 2.7 L of a highly porous styrenic polymeric bead type resin, Mitsubishi Diaion SP-700, at a flow rate of 1.5 BV/h. The first 1.5 L of eluate are discarded and the rest of the medium and an additional 1.5 L of water are eluted and pooled. The remaining portion of the medium was decolorized in a similar manner resulting in 7.5 L of pale colored solution. The two batches of decolorized material were pooled and stored in the cold if not used immediately.
Desalination Electrodialysis of decolorized Lactate solution [00217] The decolorized medium prepared as described above was subjected to electro dialysis using a desalination membrane.
[00218] The a réservoir of the Electrodialysis apparatus was charged with the decolorized sodium lactate medium and the Concentrate réservoir of the apparatus was charged with 4 L of deionized water. Electrodialysis was continued for 5 hours using a voltage of 40 V and a maximum current of 5 A.
[00219] This procedure produced a concentrated lactate stream with a typical concentration of around 66 g/L (starting at 38 g/L) and a concentrated xylose stream with a typical conductivity of 5 pS/cm (starting 34 pS/cm).
Bipolar Membrane Dielectrodialvsis [00220] The liquid in the stream in sodium lactate produced as described above can be subjected to a second electro dialysis using a bipolar membrane to produce a lactic acid solution and a sodium hydroxide solution. The procedure that can be followed is described here.
[00221] Sodium lactate (1.6 L) solution prepared by desalination electrodialysis is added to the Diluate réservoir. Deionized water (1 L) is added to each réservoir for the lactic acid and sodium hydroxide streams. The electrodialysis is carried out using a 4chamber electro dialysis cell fitted with a bipolar membrane stack. The voltage is set to 23 V and the maximum current is set to 6.7 A. The dialysis can be carried out for 5 hours or until the conductivity of the dilute stream is < 5 % of its starting value.
[00222] This procedure produced a concentrated lactate stream with a typical concentration of around 66 g/L (starting at 38 g/L) and a xylose stream with a typical conductivity of 5 pS/cm (starting 34 pS/cm) and concentration of 30g/L . The lactate stream is typîcally 96% lactic acid to 4 % xylose after the bipolar membrane dialysis. The xylose stream is typîcally 93 % xylose to 7 % lactic acid after the bipolar membrane dialysis.
[00223] Other than in the examples herein, or unless otherwise expressly specified, ail of the numerical ranges, amounts, values and percentages, such as those for amounts of materials, elemental contents, times and températures of reaction, ratios of amounts, and others, in the following portion of the spécification and attached claims may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following spécification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the embodiments. At the very least, and not as an attempt to limit the application of the doctrine of équivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[00224] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the spécifie examples are reported as precisely as possible. Any numerical value, however, inherently contains error necessarily resulting from the standard déviation found in its underlying respective testing measurements. Furthermore, when numerical ranges are set forth herein, these ranges are inclusive of the recited range end points (e.g., end points may be used). When percentages by weight are used herein, the numerical values reported are relative to the total weight.
[00225] Also, it should be understood that any numerical range recited herein is întended to include ail sub-ranges subsumed therein. For example, a range of “1 to 10” is întended to include ail sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10. The terms “one,” “a,” or “an” as used herein are întended to include “at least one” or “one or more,” unless otherwise indicated.
[00226] Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing définitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing définitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
[00227] While this invention has been particularly shown and described with référencés to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
APPENDIX
Electrodialysis Cell Unit
PCCe// ED 64 0 02
Technical Data
PCC«ll GmbH
Lebaçher Str. 60
66822 Heusweiler
Germany
Phone: ++49 · 6806-603732
Fax: ++49 - 6806 - 603731
E-maïl: pccell@electrodialysis.de www.pccell.de
Version: Jan 06
Table of Contents
1. General................... .2
2. Function.............. .. 3
3. Cëll and Parts...................... ........ .......5
4. Technical Data 8
5. Application Examples....... 10
6. Maintenance and Replacement 11
7. Application areas........ 12
8. General Remarks / Safety.......... 13
9. Warranty....... 13
10. Further Information / Contact Address......... 14
1. General
The electrodialysis cell unit PCCell ED 64 is used in laboratory electrodialysis processes to remove ions from one solution (diluate). The ions are collected in another solution (concentrate). The electrodialysis unit PCCell ED 64-2 allows to carry out different types of experiments for a variety of applications, to examine the characteristics of ion exchange membranes in use. It is concepted as an easyto-manage laboratory cell.
2. Function
The electrodialysis unit PCCell ED64-2 consists of an anode chamber, a cathode chamber ànd a membrane stack between them. With this constitution, a variety of experiments, like desalination, can be processed.
Concentrate
Fig. 1: Functional setup of an ED stack. Salts are removed in cells called Diluate and are colîected in the Concentrate. Beside this, the électrodes need a solution, the Catholyte and the Anolyte.
To run a standard ED, the membrane stack consists of n (typically 5, 10, 50 or even
100) cell pairs, which are formed by n+1 cation exchange membranes, n anion exchange membranes and 2 n spacers.
At the shown polarity (Fig. 1 ), one of the cell Systems is the diluate and the other one is the concentrate. If the polarity is changed, the function of the cell system 30 changes accordingly.
A complété ED System is set up by this ED Cell in combination with an ED pump unit, e-g. PCCell B-ED 1 and the extemal solvent tanks build (Fig. 2).
Fig. 2: A complété ED setup: it consists of the stack (upper dotted rectangle),the ED pump unit (middle) and the extemal electrolyte containers (below).
Please remark in this context, that the ED cell is Only one part of the complété system and will work properly only in combination with the other parts.
3. Cell and Parts
The PCCell ED 64 consista of several parts. They are described as follows:
Fig. 3: PCCell ED 64 sètup and functional parts
| # | Description | Art No. |
| 1,2 | Electrode end plates | |
| 3, 4, 5 | Membrane staçk | |
| 4 | Screw set |
Fig. 5: PCCell ED 64 0 02 Membrane size. Size given is in mm. Dotted square area in the middle of the membrane is the active membrane area of the cell.
4, Technical Data
Stack
Membrane size Active membrane area Membrane spacing
Number of membranes Current Connectors Processing length
110 x 110 mm cm2 electrode - membrane: ca. 1 mm over cells: 0,5 mm
Maximum 25 cell pairs mm banana plugs mm
Medium Contacting Materials End plate materials
| Cellframe Tubes Electrodes | polypropytene polyethylene Titane, Pt/lr coating |
Sp acer options
Silicone ZPVDF
End spacer
Spacer ED 64 0 04
Spacer ED 64 0 02 available
Dimensions and Weight (ca) width depth height weight
165 mm
150 mm
190 mm
2.5 kg
Electrical Connecting data
| ED 64 | |
| Type | only connect the cell with a galvanically DANGER! isolated DC current circuit. |
| Max Amp. | 5 (dépend on application, température etc.) |
| Max. Voltage | Max. 2 V / cell pair |
Hydraulfcal Connecting data
Type
Flow through electrode circuits:
Nominal flow through concentrate and diluât per single cell
Max. pressure pressure drop over cell
ED 64 connectons for 8 mm id tubes norrrinal150 l / h
4-8 l / h (10 cell pairs resuit in 40-80 l / h Flux through concentrate or diluate) transmembrane pressure has to be kept zéro:
Never pump only one of the diluate / concentrate circuits alonel
Max. 0,5 bar
5. Application Examples
The PCCell ED 64 is intended to be driven in a batch process. Process length and nominal flowthrôugh are given above.
Figure 7 shows an example of a batch desalination (conductivity of diluate against time). The effect of a single pass desalination at the start and stop time resuit in a conductivity jump. It dépends on the current, flowing and other factors. The plot shows, that it is - more ore less - proportional to the current.
ms cm ms cm: power-ΰη conductivity drop (single pass sait removal)
\
s.
X
Starting current 10 A
Current at stopping time; 1.6 A
0.50mScm-> 1-OmScm power-off conductivity raise (last pass sait removal disabled) \ \
00:00 00:20
00:40 01:00
01:20 01:40 02:00
Experimental Time
Fig. 6: A batch desalination of aqueous NaCI, about 14 l / m2.
Figure 6 shows the sait (calculated as NaCI) removal in dependence of the current at theoretical current efficiency (ce) and at 85% ce. With the PCCell ED 200 you can ëxpect for sodium chloride ce's in the range between 90 and 95 %. It dépends on current denity, concentration and other factors. The amount is given per cell pair. A 25 cell pair- unit will make 25 times of this.
Fig. 7-. Transport rate of one ED cell pair in dependence of the Amperage.
6. Application areas
Desalination of sait water
Stabilisation of wine
Whey déminéralisation
Pharmaceutical application
Pickling bath recycling
7. General Remarks / Safety
By running an electrodialysis with this cell unit, concentrated acids and bases, which are corrosive, may be produced. Adéquate protective measures hâve to be taken. At the électrodes, explosive gases and aérosol may be produced. Also in this case, appropriate protection has to be ensured. The cell has to be run in a tank large enough to çollect any liquids passing out of the system.
8. Further Information / Contact Address
For further information, visit our web site www.electrodialysis.info. In case of any technical questions, please contact
PCCell GmbH
Dr. Patrick Altmeier
Phone: ++49-(0)6806/603730
Fax: ++49-(0)6806/603731 email: pccell@electrodialysis.de
Note:
The «formation in thé handüng instructions is presented ii jpod faith, and ail recommendations or suggestions are made without guarantee. lhe products are intended for use by persons hatving technical skill, at their own discrétion and risk. PCCell is not responsble for any risks or BabiHties which may resuit from the use of it's products.
Technicel Pdjpèft ’ ;
High Water Recovery with Electrodialysis Reversai
Author: Robert P. Àïlison
Reprinted from Proceedings gf 1993 AWWA Membrane Conférence, by permission. Baltimore, MD August, 1993.
Note: GE Water & Process Technologies purchased lonlcs in: 2005.
introduction
For many membrane dësa ination Users, the need to achieve; maximum water recovery is a prime priority. For some, source water Is limited, allocated pr otherwise régulated. It i's now reçognized that wthdrawas from many aquifers exceed the recharge with resulting drops in water tables, land sübsistënce and saltwater intrusion in coasfdl areas. Surface supplies can also be limited, as was so c.learly évident during the récent California drought For users. who purchase.their feedwater. costs are. risirig and can represent a substantiai portion .of their total treated water cost
Concentrate disposai is also getting rhore expensive and complicated as régulations intended to preserve the quality of water supplies : and the environment become moré strict. Permits for surface .discharge can be djfficult to impossible to get Dischdrge to sewers and deepwells can substantially increase costs. Zéro Liquid. Dis.charge‘ fqcilities, where ail liquid wastes one purified for réuse, can hâve very high costs,
Electrodialysis Reversai (EDRI is a desalination process where salts are passed through the membranes.instead of wateras in reverse asmosis(RO). The process is fundamentally. different from RO a nd has its own distinct capabilities and li mitatians an water recovery, The capabilttiës Of the. EDR process are helping mariy municipal and industrial □sers in desalination .applications, where high
water recovery is Important for resource conservation and cost contrai.
Sou rcè of EDR Wastewa ter
The source water feed to an EDR system is divided into three streams as shown in Figure 1. The largest f low is· the dilute feed which passes through the stocks once and exits as desalted product The second stream; terméd concentrate makeup, is fëd to a concentrate stream being recirculàted through the. stocks. At the exit from the stocks there is an overflaw to waste. The concentrate makeup flow rate controls the average number of times the concentrate is recirculàted, and thereforé, is the main rileans of controlling recovery in an EDR system; The third stream.is electrode compartment flush water, which oh most Systems is 1% of the· dilute flow. NormallljZ this water is. directed to waste after it passés through the stocks, but it. can be used as a: portion of the concentrate makeup water to further improve Water recovery.
..................! > .................' j
Figure i: EDR Ffow Diagram
A small amount of the dilute stream water flow is transferred to the concentrate. stream as it passes through the stock. First, water is transferred through the membrane with the passage of ions: This water transfer amounts to 0:15% to 0.45% of the dilute flow per 10Q0 ppm (rrig/LI. of salts removed. Membranes with the best résistance to internai scale formation tend to hâve water transTrademarkoiGineral HectricCortpany; may be règisured In one or more countnei
O201D. General ElectncCompaiy. Ai nghte resenÆtf
Table 1: Suffolk, VA EDR Unit Flow Summary fer near the higher value. Internai leakage also occurs between the dilute stream and the concentrate stream which is approximately 0.2.5% to 0.50% per stage. The concentrate stream is normally operated about 1 psi lower in pressure than the dilute stream sa that this leakage Will be from the dilute stream to theconcentrate stream. Water transfer and cross leakage do not reduce water recovery. These flows are calculated as part ofthe concentrate makeup flow in the plant design. The actual controlled concentrate makeup flow is reduced proportionately.
The periodic reversai of the DC power polarity interchanges the solutions in the individual spacers, Spacers carrying the dilute flow in négative polarity çarry concentrate in the positive polarity. Automatic inlet and Outlet diversion valves direct the dilute and concentrate flows to the correct, spacers for each polarity.
While thé concentrate is being flushèd out during reversai, poor quality product is produced. This is diverted to waste by a conductivity-controlled automatic valve. By timing the operation ofthe automatic diversion valves and the DC polarity reversai of each stack to the flow through the System, high conductivity product is produced for only 36 seconds. This phased polarity reversai occurs every 15 to 30 minutes. The high conductivity or off spécification' product from the “phased reversai represents 2% to 4% waste. This waste is high TDS concentrate and cannat be recycled to the feed or concentrate makeup,
Some Exampies
The highest water recovery EDR plant in operation is the 376 mgd (14,233 m3/day) facility operated by the Cityof Suffolk, VA. The plant has three stages and achieves 94% water recovery. Table 1 shows a flow summary for one of the three EDR units broken down to show where the waste is generated. The units hâve no continuous chemical feeds. A 149 gpnri (56 Ipm) concentrate makeup flow is used to control calcium carbonate scaling potential in the concentrate. If the units did not require this controlled concentrate makeup flow, waste could be reduced to 43,1 gpm giving an ultimate recovery capabilrty of 95.3%.
| WewmBSnÎSftl | |
| 94» | |
| iA-SgawlSiW twl | |
| 12Β«»Ηφ5Ι)><ιΛ | |
A 5 mgd EDR plant located on Grand Canary Island opérâtes on a 5.000 to 7,000 ppm (mg/l) feedwater dt 85% Water recovery. Table 2 shows the unit flow summary. The controlled concentrate makeupflow is approximately 1/2 of the total waste. The ultimate water recovery capabilrty based on flows of this plant is only 91.8%. The higher TDS increases water transfer and the additional stages increase cross leakage.
Table 2:Grand Canary Island EDR UnitFlowSummary
| 4û9.1gjm: | TôialiEDRFeeii : ; |
| TûMI <WàterSSüniçrj· | |
| WWttÿWtet | |
| ÏQ^’giKn ; | |
The water recovery of this plant is rêally limited by. two additional physical factors. The first is a phenomenon called 'shorting·. Figure 2 shows how leakage currents can travel sideways through the membranes and pass down a concentrate manifold hole. If the concentration is sufficiently conductive, the current passing through the membrane to themanifold hole can create enough heat to soften the spacer material and cause it to deform. This limitation can be overcome by a variéty of means which increase costs. The second limft is imposed bÿ membrane current efficiency properties. Figure 3 shows the DC power consumption and membrane current efficiency vs, water recovery for an. EDR unit desalting 2,000 ppm (mg/l) NaCl solution to 334 ppm (mg/l). Membrane efficiency is related to the différence in normality between the dilute and concentrate streams. As
water recovery is increased, the concentrate normality increases and current efficiency drops,.raising power consumption.
i.oowr
Figure2: EDR Stock Shorting
Figure 3: Efficiency and Power Consumption vs, Water Recovery
Suffolk can achieve 94% water recovery because the relatively low TDS of the feedwater results in relatively low normality différence between the dilute and concentrate streams. The Grand Canary Island plant has a much greater normality différence and power consumption rises sharply above 86% water recovery. Anion exchange membranes are available that hâve better current efficiency which improves water recovery capability. These membranes tend to be subject to more internai scale formation which can make their use undesirable on many waters. Cation exchange membranes hâve been substantially improved since the Canary Islands plant was built in 1985. Long term testing at this plant show these new membranes substantiqlly improve current efficiency qnd reduce power consumption. They are now standard on ail new plants.
Concentrate Sealing Limite
The water recovery capability of nearly ail EDR plants is limited by the poteritial for salts of limited solubility to precipitate from the concentrate stream as scale. The polarity reversai of EDRalter nately exposes membrane surfaces and the water flow paths to concentrate with a tendency to precipitate scale and desalted water which tends* to dissolve scale. This allows the process to operate with supersaturated concentrate streams up: to spécifie limits without chemical additions to prevent scale formation. If chemicals are qdded to the concentrate, higher levels of supersaturation can be achieved.
Calcium Carbonate
The design limit for CaCC3 without antiscalants is an Langelier Saturation Index (LSI) of +1.8. Actual scale précipitation starts at an LSI near +2.2. This limit is sufficiently high that few EDR units need any chemical additions to prevent CaCO3 sealing from high concentrate LSL Where chemical addition is used, acid or carbon dioxide addition to the concentrate is employed.
Antiscalants can be used as on alternative to acid or CO2 addition to the concentrate. A 500,000 gpd EDR unit was operated for seven weeks at a concentrate LSI of +3.0 using a polymer anflscalant Another EDR unit was operdted for 5,000 hours at an LSi of +2.7 using sodium hexametaphosphate antiscalant This apprùach has not been adopted in general for three reasons.
1. Antiscalants must be dosed at the correct amount Too little results in sealing and too much can foui the membranes.
2. Antiscalant dosages are difficult to monitor. There is no easy way to test the concentrate for correct dosage. With acid or COj, pH is easilÿ monitored.
3. The concentrate LSI only needs to be reduced to + 1.8. The required acid or CO; dosages are almost always very small. There is no significant cost advantage favoring the use of antiscalants over acid or COS.
Calcium Sulfate
The design limit for CaSO,, saturation without antiscalant addition is an ion product of 2.25 x Ksp; The real limit where précipitation starts is near 4 x Ksp. Dell City, Texas has operated a 150,000 gpd (568 m3/day) EDR system since 1975 with the concentrate CaSO4 ion product at 3.5 x Ksp without antiscalant addition. The limit cannot be increased by acid or CO2 addition, as pH adjustment does not
increase the solubility of CaSOs The only way to increase water recovery is to use antiscalants.
In 1981 and 1982. the EDR limits of sustained operation at high CaSOà saturations with sodium hexametaphosphate antiscalant addition were explorèd under an OWRT contract at Roswell, New Mexico. The final test in this program wps operation of a 50,000 gpd EDR unit with thé concentrate CaSO4 ion product at an average of 12.5 x Ksp for over 5,0.00 operating hours. Inspection of the membranes at the conclusion of the test showed the membranes hadonly small amounts af scqle, even though antiscalant addition was lost for four days during the test. Analysis of the membranes at the conclusion of thè test indicated good performance properties. In factthe membranes were used in another plant after the Roswell test for about seven years.
Since the landmark Roswell study, a number of EDR units hqve opérated qt high CaSO« saturations in the concentrate. In 1988, Sarasota County, Florida installed a mobile 300,000 gpd EDR atitsSorrento..facility to supplément wcrter produced by an RO plant operating at 50% water recovery. The water recovery of the EDR plant Is only 70%. but the CaSOt ion product of the concentrate is 5.75 x Ksp. Scale formation is préveiited by the addition of 4.3 ppm (mg/ll of a polyacrylate antiscalant to the concentrate.
Sarasota County is now constructing a 12 mgd desalination facility scheduled to start operation in 1994. Their withdrawals of groundwater are regulated and restricted .due to concerns of aquifèr overwithdrawal and quality dégradation. The cohcentrate is to be injected into deepwells due to environmental concèrn and régulations controlling surface discharge. They selected EDR for its proven ability to operate ata.high CASOa saturation level, which translates ta an 85% water recovery for this plant
Barium Sulfata
BaSO4 scales· started to be encouritered In EDR plants in the 1980s with the growing trend to higher water recoveries: It has now been encountered in about ten plants. It précipitâtes on the walls of the concentrate recirculation piping and in the concentrate pump. It adhères strongly to metals, but breaks off the PVC piping when the scale is abaut .020 inches thick. Theflakes then pass to the EDR. stocks. Chemical flushes cannot dissolve the scale. The stocks must be disassembled for removal. The first user to encounter BaSO4 scale has 275,000 gpd (1041 m 3/day) units. The problem oqcurs intermittently as the quality of their surface water supply varies. This user simply added strainers to the piping before the stocks to catch the flakes and hasoperated this way for over 10 years, It is now known that the threshold point fqr BoSO,. précipitation in EDR is an ion product of 100 x Ksp when no antiscalants are used,
The limit with antiscalant addition is currently unknown. Several plants are operating at a BaSOi ion product of 150 x Ksp and two plants hâve reached an ion product of 225 x Ksp with a. polymer antiscalantdcsageof2to5 mg/l to thé concentrate
Strontium Sulfate
SrSOa scale has not been detected in any EDR plants. Analyses of concentrate samples from many plants show the plants with the highest supersaturations are. operating at an ion product of 4 x. Ksp. The projected limit is an ion product about 8 x Ksp without antiscalants.
Calcium Fluoride
CaF2 précipitation has never occurred in an EDR plant. Plants are operating with ion products 500 x Ksp and much higher levels hâve been encountered in two industrial pilot studies with no précipitation. There are no projected limits for saturation levels.
Silica
Silica in waters below pH 9.5. is essentially nonionic and is not removed or concentrated by EDR. Tests show silica levels are equal in thè feed, product and brine of operating EDR plants. High water recoveries can be obtained on high silica waters because silica does not limit EDR recovery.
The 5 mgd plant on Grand Canary Island is a perfect example of this cdpability. The feedwater silica varies from 50 to 60 ppm (mg/l), yet the water recovery is 85%. RO would hâve a lower operating cost on this higher TDS water, but recovery would hâve to be much lower. The feedwater is purchased at a cost af over US$1 per thousand gallons (per 3.8m?|. The RO cost advantage is lost with the much larger volume of waste required to prevent silica sealing.
Conclusion
Thé maximum water recovery that can be achleved with EDR destination for any given source water dépends on a variety of factors. In most applications the water recovery is limited by the potential for scales to precipitate from the concentrate. EDR has the ability to operate at high supersaturations of sçale-forming salts in the cpncentrate and is unaffected by silica. This translates to a high water recovery capability. These are the reasons:EDR is meeting the needs of users in many applications where high water recovery is a priority.
Electrodialysis (ED) and Electrodialysis Reversai (EDR)
Electrodialysis (ED) is an electrochemical process in which ions migrate through ion-selective semipermoable membranes as a resuit of their attraction td two electricallÿ charged électrodes. ED Is able to remove most charged dissolved ions.
1.0 Applicable Contaminants
ED/F.DRisanEPA BAT for barium, nitrate and nitrite, sélénium, andTDS.
2.0 Description of Technology
Pretreatment Typical operation requlres: the addition ofa scale inhibitor to prevent scaling and. reduce the concentrate LSI below 2.1 in tlie concentrate stream, residual chlorine concentration of 0.5mg/L to prevent biological growth, anda cartridge filter (10-20 pm) prior to the ED/EDR system Air stripping can also be used prior to ED/EDR in order to remove H2S[âJ. Also, the feed water must be within the limitations of an ED/EDR system (see section 2.2).
Technology Description Electrodialysis is a process that dépends on the principal that most dissolved salts are positively or negatively charged and they will migrate to électrodes with an opposite charge [2]. Sélective membranes that are able to allow passage of either anions or cations make séparation possible [2]. ED uses these membranes in an altemating fashion to create concentrate and product streams
The anions are able to pass through the anion-selective membrane, but are not able to pass by the cation-selective membrane, which blocks their path and traps the anions in the brine stream (Figure 1). Similarly, cations move in the opposite direction through the cation-selective membrane under a .négative charge and are trapped by tlie anion-selective membrane [2]. An ED unitis able to remove from 50% tô 94% of dissolved solids from a feed water, up to 12,000 mg/L TDS [3,7]. Voltage input, and process configuration (number of stacks or stages dictâtes the viable percent removal. TDS removal is generally limited by économies. The çost ofED increasesas the feed water TDS increases. The typical operating conditions are 1,200 mg/L TDS, high hardness and high silica [4].
Figure 1. Electrodialysis FYocess (IJ.
Electrodialysis 1
A typical ED System includes a membrane stack with a number of cell pairs, each consisting of a cation transfer membrane, a demitieràlized flow spacer,. an anion tiansfér membrane, and a concentrate flow spacer. Compartments for the électrodes are at opposite ends ofthe stack. The électrodes are continually flushed to reduce fouling or scaling.
Rècycling the concentrate stream and discharging concentrate to waste, or blowdown, is common ànd called feed-and-bleèd mode [2]. This is necessary because of the fact that there are Sharp différences· in flow rates between the product andbrine streams. Diluate flow is about 10 times the flow of the brine stream; this différence in flows créâtes pressure imbalances, requiring concentrate recycle [5].
Membranes are usually made out of cation-or anion-exchange resins made into sheet form. ED spaçers are made out of HDPE, and the électrodes are composedof an inert métal. Membrane sélection is based on careful review of raw water characteristics.
Electrodialysis Reversai (EDR) is similar to ED but the polarity of the électrodes is regularly reversed, thereby freeing accumulated ions on the membrane surface, This process minimizes the effect of inorganic scaling and fouling by converting product streams into waste streams [6]. This process requires additional plumbing and electrical controls, but increases membrane life. EDR does not require added chemicals, and eases cleaning as welL
Maintenance ED membranes are durable, can run under a wide range of pH conditions (pH211), and endure high températures during cleaning [4], They can be removed from the unit and scrubbed if necessary. Ifoperated property, membranes hâve an average life of 12 to 15 years [4]. Solids Can be flushed out by turning the poWef off and letting water circulate through the stack The ED stâçk must be disassembléd, mechanically cleanèd, and reassembled at regular intervals. They can also be cleaned using a 5% hydrochloric acid solution [SJ.
Waste Disposai Tlie concentrate waste stream, electrode cleaning flows, and residuals from the pretreatment process will be a part of a typical waste stream flow and will require disposai. Common disposai methods include; surface water discharge, évaporation ponds, etc. Spent membranes will also require disposai.
Beneiïts • ED and EDR can operate with minimal fouling or scaling, or chemical addition.
• Low pressure requirements.
• ED and EDR facilities are quieter than RO.
• Long membrane life expectancy.
• Unaffected bÿ noii-ionic sèalaiits such as. silica1.
• Low chemical usage for pretreatment*.
• Ability to treat feed water with higher SD1, TOC and silica concentrations, and more turbidity than RO*.
• Can operate with up to 0.5 ppm of free chlorine in the feed waterto control the biological matter in the.feed water?
Electrodialysis 2
Limitations • TDS economical up to 8,000 ppm, but often run at waters of 1,200 ppm [6,9] • pH: 2.0 to 11.0 • TOC: up to 15 mg/L • Free Chlorine; 0.5 ppm with spikes up to 15-20 ppm • Turbidity: up to 2 NTU • Iron (Fe+2): 0.3 ppm • Mn (*2): 0.1 ppni • H;S : up to i ppm • SDI: 15 (5 min SDI)
3.0 Example Treatment Train
The conventional EDR treatment train typîcally includes raw water pumps, débris screens, rapid mix with addition of an antiscalant, slow mix floccülator, basin or clarifier, gràvity filters, EDR membranes, chlorine disinfection, and clearwell storage. Microfiltration (MF) could be used in place of flocculation, sédimentation, and filtration.
Waste Discharge
4.0 Safety and Health Concerns • Produces hazardous gasses, such as chlorine, hydrogen, H^S, etc.
• Electrical hazardous
5.0 Référencés
1. Buros, O. K. (2000). The ABCs of Desalting. Topsfield, International Desalination Association, Saline Watér Conversion Corporation.
2. American Water Works Association, and American Society of Civil Engineers. Water Treatment Plant Design. Ed. Edward E. Baruth. Fourth ed. New York: McGraw-Hill Handbooks, 2005.
3. General Electric. (2008). Electrodialysis Reversai (EDR). Retrieved 9/15/08, from http://www.gewater.com/products/equipmenf/ed edr edi/edr.jsp.
Electrodialysis 3
4. Reahl, E. R. (2008). Half A Century of DèsàliriatiOn with Electrodialysis. from httD:.,7www.gewater.com/pdffrechnical Papers Ctist/Americas/English/TPlO38EN.pdf '5. Perry, Robert H., Don W. Green, and James O. Maloney. Perrv's Chemical Eiigineers Handbook. Seventh ed. New York: McGraw-Hill, 1997.
6. Bureau of Réclamation (2003). Desalting Handbook for Planners. Départaient of the Interior. Denver.
7. Trussel Technologies. Desalination Technologies. Pasadena, 2008. Trussel Technologies., 6/11/2008. <http://www.1nisselltech.com/tech desalination..-isn>,
8. Allison, R.P. (2001). “Surface and Wastewater Desalination by Electrodialysis Reversai” from http:ZAvww.gewater.com/pdf/rechnical Papers Cust/Americas/Enelish/TP1022EN.pdf
9. Kieman, J. and A. J. M. v. Gottberg (1998). Sélection of EDR Desalting Technology Rather than MF/RO for the City of San Diego Water Réclamation Project. North American Biennial at Conférence and Exposition. GE Water & Process Technologies,
Contact Information
This Fact Sheet was produced by the TSC’s Water Treatment Engineering Team. Please address any questions or commenta to:
Contact: Bob Jurenka
Email: wtprimer@usbr.gov
Phone: (303)445-2254
Web: http://www.usbr.gov/omts/water/publications/orimer.htnil
Révision Date: 09/20/10
Electrodialysis 4
The Eurodia Industrie bipolar membrane electrodialysis unit for the conversion of sodium acetate into reusable acetic acid and caustic soda:
More than five years of successful operation (Published in Membrane & Séparation Technology News - March 2006)
In early 2003, Eurodia Industrie commissioned a new bipolar membrane electrodialysis (EDBM) unit at the site of a specialty chemical producer in Germany. Its purpose is to convert a byproduct stream of Sodium Acetate from the production of vitamins into Acetic Acid that can be reused in the process and Sodium Hydroxide to be used in the waste water treatment facility. As a resuit, the volume of waste (organic load) is significantly reduced and the acid and base values can be recovered. This article will describe the successful operation of this plant over the last three years.
EDBM combines in an electrodialysis stack conventional ion exchange membranes with bipolar membranes to allow the conversion of aqueous sait streams into the acids and bases. Under the action of a DC current, the bipolar membranes effectively split water molécules into H+ and OH ions. These ions combine with the anion and cation of the sait to form the acid and the base. With a three-compartment configuration using anion-exchange, cation-exchange, and bipolar membranes, three loops are circulating in the stacks: acid, base, and sait such as Sodium Chloride. As shown in the schematic below, the two-compartment configuration with bipolar and cation-exchange membranes is used preferably with the salts of weak acids and strong bases, such as Sodium Acetate. Because organic acids are weakly dissociated it is not possible/practical to hâve a separate acid loop and no anion-exchange membranes are required. In such stacks, the two product streams are an aqueous solution of NaOH (maximum concentration 8w%) and the organic acid mixed with some remaining organic sait for a sufficient conductivity: the higher the sait feed concentration, the higher the conversion rate that can be achieved. More than a dozen EDBM Systems are in operation worldwide, mainly for specialty chemicals applications.
At the German plant, the Sodium Acetate stream is fed at an average concentration of 22-23 w% and the acid is produced at a concentration of 18-19 w% (3.2-3.5 M). The NaOH is produced at an average concentration of 6-6.5 w%, sufficient for reuse in the water treatment plant. Since there is also a transport of water from the acid into base loop, the conversion rate is above 90%. The unit processes 1.1 to 1.3 m3/hour of feed and converts more than 400 kg/hour of Sodium Acetate.
Since the feed contains low levels of multivalent cations (Ca, Mg, Fe, Ou, etc.), a pretreatment step is required to reduce the total concentration below 1 ppm to avoid précipitation as hydroxides in the stacks: two ion exchange resin columns hâve been installed for continuous
operation. The sait is then converted in two EUR40B-bip EDBM stacks (see picture below), with a total cell area of 255 m2 (510 m2 of membrane area). The EDBM stacks run in an automatic batch mode with the salt/acid conductivity decreasing from 70 mS/cm to 11.5 mA/cm: when the conductivity reaches such minimum, the acid product is pumped to the storage tank. The overall current efficiency is optimized thanks to proprietary designed spacers.
The EDBM unit has been designed and constructed according to CGMP principles and to customer spécifications. Commissioning has been completed within a short time and, since, it has met the needs of the customer and always been in operation when required. The automatic operation is controlled by a PLC. The unit has been installed in a stand-alone building while the overall control room is in an adjacent building. In addition, remote caméra monitoring allows that an operator must only be in the building for less than 30 minutes per day. The electric cabinets and rectifiers are located in the same building as the EDBM stacks. A dilute NaOH solution is used as the electrolyte solution and a blower allows the safe venting outside the building of the small amount of hydrogen and oxygen gases that are generated at the électrodes. It is possible to install a modem to allow remote monitoring of plant operation and optimization of operating parameters.
S
It is worthwhile to note that the performance of the system hâve continuously exceeded the design and guaranteed parameters: especially for the acid concentration and the acid production rate, as well as the power consumption. While a membrane life of 12,000 hours has been guaranteed, the membranes hâve run for more than 8,000 hours so far with no sign of 5 détérioration. For a similar application at another site, the bipolar membrane life has exceeded
25,000 hours while the life of the cation-exchange membranes is about 15,000 hours. The DC current is set at 340 A (équivalent to 85 mA/cm2) and the average voltage remains at 185 V per half-stack, or less than 1.7 V/cell. Since cell maintenance and power consumption are the main operating costs, the économie projections show a payback for the customer of less than two 10 years.
The performance of the EDBM unit demonstrates that, with a good design and the adéquate pretreatment, users will hâve a very successful and trouble-free operation. Of course, this 15 equipment requires the same amount of care as any chemical process step and the plant operators hâve shown their commitment to the technology. From this expérience, it is clear that bipolar membrane electrodialysis can be reliably used in chemical processing with the potential of attractive financial returns.
Claims (28)
- L A method comprising:removing salts, partially ionized acids or fully ionized acids, from saccharified biomass liquids utilizing an electrodialysis system.
- 2. The method of claim 1, wherein the electrodialysis system utilizes electrodialysis or electrodialysis reversai.
- 3. The method of claim 1 or 2, wherein the saccharified biomass liquids comprises a reduced recalcitrance, cellulosic or lignocellulosic material that has been saccharified.
- 4. The method of claim 3, wherein the cellulosic or lignocellulosic material has had its recalcitrance reduced by treatment with ionizing radiation.
- 5. The method of claim 4, wherein the ionizing radiation is in the form of accelerated électrons.
- 6. The method of any one of claims 3 through 5, wherein the cellulosic or lignocellulosic biomass has been saccharified utilizing one or more enzymes.
- 7. The method of any one of claims 3 through 6, wherein the cellulosic or lignocellulosic biomass has been saccharified utilizing one or more acids.
- 8. The method of claim 7, wherein the acid is sulfuric acid.
- 9. The method of any one of the above claims, wherein an ionic strength of the saccharified biomass liquids prior to electrodialysis is between about 500 and about 50,000 pS/cm, and wherein an ionic strength of the saccharified biomass liquids after electrodialysis is between 1 and 100 pS/cm.---
- 10. The method ofany oneofthe above claims, wherein the salts^partially----ionized acids or fully ionized acids removed utilizing the electrodialysis system comprise at least one element selected from the group consisting of P, K, Mg, Na, Ca, S,O, Mn, Al, Zn, Si, Cl and Fe.
- 11. The method of any one of the above claims, further comprising purifying the saccharified biomass liquids by a method selected from the group consisting of chromatography, filtration, centrifugation, précipitation, distillation, complexation and combinations thereof.
- 12. The method of claim 11, wherein précipitation comprises addition of one or more solvents or non-solvents to precipitate one or more undesired components.
- 13. The method of claim 12, wherein the solvent is selected from the group consisting of methanol, éthanol, isopropanol, acetone, ethyl ether and tetrahydrofuran.
- 14. The method of claim 12, wherein the solvent is methanol.
- 15. The method of any one of the above claims, wherein the saccharified biomass liquids comprise one or more fermentation products.
- 16. The method of any one of the above claims, wherein the saccharified biomass liquids comprises liquids that hâve had a fermentation product distilled therefrom.
- 17. The method of claim 16, wherein the fermentation product is an alcohol.
- 18. The method of claim 17, wherein the alcohol is éthanol.
- 19. The method of any one of the above claims, further comprising decolorizing the saccharified biomass liquids utilizing a decolorizing agent.
- 20. The method of claim 19, wherein the decolorizing agent is selected from the group consisting of powdered carbon, granular carbon, extruded carbon, bone char carbon, bead activated carbon, stryenic resins, acrylic resins, magnetic resins, decolorizing clays, bentonite, attapulgite, montmorillonite, hormite and combinations thereof.
- 21. The method of claim 19 or 20, wherein after decolorizing the color of the solution is less than about 100 color units.
- 22. The method of claim 19 or 20, wherein after decolorizing the color of the solution is less than about 10 color units.
- 23. The method of claim 19 or 20, wherein after decolorizing the color of the solution is less than about 5 color units.
- 24. The method of any one of the above claims, wherein utilizing the electrodialysis System comprises applying a voltage of between about 10 and 150V across ion sélective membranes while flowing the saccharified biomass liquids past the membranes.
- 25. The method of any one of the above claims, wherein the saccharified biomass liquids comprise one or more saccharides.
- 26. The method of any one of the above claims, wherein the saccharified biomass liquids includes a sugar selected from the group consisting of xylose, glucose, arabinose, fructose and mixtures thereof.
- 27. The method of claim 26, wherein the sugar includes xylose and the purity of the xylose after utilizing the electrodialysis System is at least about 80 wt.%.
- 28. The method of claim 27, wherein the sugar includes arabinose and the purity of the arabinose after utilizing the electrodialysis System is about 0 to lwt. %.
Applications Claiming Priority (15)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US61/774,750 | 2013-03-08 | ||
| US61/774,735 | 2013-03-08 | ||
| US61/774,775 | 2013-03-08 | ||
| US61/774,740 | 2013-03-08 | ||
| US61/774,746 | 2013-03-08 | ||
| US61/774,761 | 2013-03-08 | ||
| US61/774,744 | 2013-03-08 | ||
| US61/774,752 | 2013-03-08 | ||
| US61/774,780 | 2013-03-08 | ||
| US61/774,773 | 2013-03-08 | ||
| US61/774,754 | 2013-03-08 | ||
| US61/774,723 | 2013-03-08 | ||
| US61/774,684 | 2013-03-08 | ||
| US61/774,731 | 2013-03-08 | ||
| US61/793,336 | 2013-03-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| OA17469A true OA17469A (en) | 2016-12-30 |
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