Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07H—SUGARS; DERIVATIVES THEREOF; NUCLEOSIDES; NUCLEOTIDES; NUCLEIC ACIDS
  • C07H1/00—Processes for the preparation of sugar derivatives
  • C07H1/06—Separation; Purification

Definitions

• the present invention relates to novel viscous carbohydrate compositions, to methods for the production thereof, and to methods for processing lignocellulosic materials for producing the novel viscous carbohydrate compositions therefrom as well as to the production of further useful products.
• carbohydrate sources contain as their main components cellulose, hemicellulose and lignin and are also referred to as lignocellulosic material. Such material also contains mineral salts (ashes) and organic compounds, such as tall oils.
• Cellulose and hemicellulose which together form 65-80% of the lignocellulosic material, are polysaccharides and their hydrolysis forms carbohydrates suitable for fermentation and chemical conversion to products of interest. Hydrolysis of hemicellulose is relatively easy, but that of cellulose (which typically forms more than one half of the polysaccharides content) is difficult due to its crystalline structure.
• Presently known methods for converting lignocellulosic material to carbohydrates involve enzymatic-catalyzed and/or acid-catalyzed hydrolysis. In many cases, p re-treatments are involved, e.g. lignin and/or hemicellulose extraction, steam or ammonia explosion, etc.
• Acid hydrolysis of lignocellulosic material was considered and tested as a pre-treatment for enzymatic hydrolysis.
• acid could be used as the sole hydrolysis catalyst, obviating the need for high-cost enzymes.
• Most of the efforts focused on sulfuric acid and hydrochloric acid (HCI), with preference for the latter.
• HCI-based hydrolysis of lignocellulosic material was implemented on Industrial scale.
• Such hydrolysis forms a hydrolyzate stream containing the carbohydrate products, other soluble components of the lignocellulosic material and HCI. Since the lignin fraction of the material does not hydrolyze and stays essentially insoluble, the process also forms a co-product stream containing the lignin dispersed in or wetted by an aqueous solution of HCI.
• HCI acts as a catalyst, it is not consumed in the process. It should be separated from the hydrolysis products and co-products and recycled for reuse. Such separation and recycle presents many challenges, some of which are listed in the following.
• the recovery yield needs to be high in order to minimize costs related to acid losses, to consumption of a neutralizing base and to disposal of the formed salt.
• residual acid content of the product and the co-products should be low in order to enable their optimal use.
• Acid recovery from the hydrolyzate should be conducted in conditions (mainly temperature) minimizing thermal and HCI-catalyzed carbohydrates degradation. Recovery of HCI from lignin co-product stream is complicated by the need to deal with solids and by the need to form HCI-free lignin.
• HCI forms an azeotrop with water. Since HCI is volatile, recovery from HCI solutions by distillation is attractive in generating gaseous, nearly dry HCI stream. Yet, due to the formation of the azeotrope, such distillation is limited to removing HCI down to azeotropic concentration (about 20%, depending on the conditions). Further removal of HCI requires co-distillation with water (to form vapor phase wherein HCI concentration is about 20%). Therefore, in order to reach complete removal of the acid from the carbohydrate, distillation to dryness would be required. Alternatively, addition of water, or steam stripping, dilutes the residual acid to below the azeotropic concentration. As a result, mainly water evaporates, i.e.
• An objective of the present invention is to provide a method for high yield recovery of HCI from the products and co-products of HCI hydrolysis of lignocellulosic material.
• a related objective is to recover that acid at high concentration to minimize re-concentration needs.
• Another objective is to produce carbohydrates and co-products of high quality that are essentially free of HCI.
• Still another objective is to form a carbohydrate composition with minimal moisture and HCI contents that is fluid enough for low-cost spray-drier based removal of residual HCI.
• the present invention provides according to a first aspect a viscous fluid comprising at least 75%wt carbohydrate (as calculated by 100 times carbohydrate weight divided by the combined weights of the carbohydrate and water) between 2%wt and 25%wt water, between 0%wt and 25% wt of a second organic solvent and between 10%wt and 55%wt HCI (as calculated by 100 time HCI weight divided by the combined weights of HCI and water), which second organic solvent is characterized by at least one of:
• (c2) having a solubility in water of less than 15%, and forming a heterogeneous azeotrope with water wherein the weight/weight ratio of the second organic solvent to water is in the range of between 5 and 0.2, and wherein the solubility of water in the organic solvent is less than 20%.
• the viscosity of the viscose fluid as measure at 80°C by the Brookfield method is less than 150cP.
• the HCI/water weight/weight ratio in the viscous fluid is in the range between 0.2 and 1.0, the carbohydrate/water weight/weight ratio is in the range between 2 and 20, and the HCI/carbohydrate weight/weight ratio is in the range between 0.02 and 0.15.
• the second organic solvent/water weight/weight ratio in the viscous fluid is R2, wherein the second organic solvent forms a heterogeneous azeotrope with water and the second organic solvent/water weight/weight ratio in the azeotrope is R22 and wherein R2 is greater than R22 by at least 10%.
• the second organic solvent forms a heterogeneous azeotrope with water, wherein the second organic solvent has a boiling point at 1atm in the range between 100°C and 200°C and wherein the heterogeneous azeotrope has a boiling point at 1atm of less than 100°C.
• the viscous fluid is under a pressure of less than 400mbar.
• the viscous fluid comprises glucose and at least one carbohydrate selected from the group consisting of mannose, galactose, xylose, arabinose, and fructose, more preferably at least two carbohydrates selected from the group consisting of mannose, galactose, xylose, arabinose and fructose.
• the present invention provides, according to a second aspect a method for the deacidification of a first aqueous solution comprising the steps of
• providing the first aqueous solution comprises hydrolyzing a polysaccharide-comprising material in an HCI- comprising hydrolysis medium, wherein HCI concentration is greater than azeotropic.
• the weight/weight ratio of the second organic solvent to water in the second evaporation feed is R23, wherein the weight/weight ratio of the second organic solvent to water in the azeotrope is R22 and wherein R23 is greater than R22 by at least 10%.
• the method further comprises the steps of- condensing the vapors in the second vapor phase to form two phases, a second organic solvent-rich one and a first water-rich one, separating the phases, using the second organic solvent-rich phase in step (ii), and using the first water- rich phase for generating the hydrolysis medium.
• the method further comprises the step of spray drying the viscous fluid to form a de-acidified solid carbohydrate composition.
• the weight/weight ratio of HCI to carbohydrates in the de-acidified solid carbohydrate composition is less than 0.03.
• the present invention provides, according to a third aspect a lignin composition comprising between 10%wt and 50%wt lignin, less than 8%wt water, between 50%wt and 90%wt of a first organic solvent and less than 10% HCI (on an as is basis), which first organic solvent is characterized by at least one of:
• the lignin composition further comprises at least one carbohydrate and wherein the concentration of the carbohydrate is less than 5%wt.
• the weight/weight ratio of the first organic solvent to water is R1 , wherein the first organic solvent forms a heterogeneous azeotrope with water, wherein the weight/weight ratio of the first organic solvent to water in the azeotrope is R12 and wherein R1 is greater than R12 by at least 10%.
• the first organic solvent forms a heterogeneous azeotrope with water, wherein the first organic solvent has a boiling point at "latm in the range between 100°C and 200°C and wherein the heterogeneous azeotrope has a boiling point at 1 atm of less than 100 °C.
• the present invention provides according to a fourth aspect, a method for the deacidification of a second lignin stream comprising the steps of
• providing the second lignin stream comprises hydrolyzing a lignocellulosic material in an HCI-comprising hydrolysis medium, wherein HCI concentration is greater than azeotropic.
• the weight/weight ratio of the first organic solvent to water in the first evaporation feed is R13, wherein the weight/weight ratio of the first organic solvent/water in the azeotrope is R12 and wherein R13 is greater than R12 by at least 10%.
• the method further comprises the steps of condensing the vapors in the first vapor phase to form two phases, a first organic solvent-rich one and a second water-rich one, separating the phases, and using the first organic solvent-rich phase in step (ii).
• the present invention provides, according to a fifth aspect a method for the production of a carbohydrate composition comprising - - ⁇
• (c2) having a solubility in water of less than 15%, and forming a heterogeneous azeotrope with water wherein the weight/weight ratio of the second organic solvent to water is in the range of between 5 and 0.2, and wherein the solubility of water in the organic solvent is less than 20%;
• the weight/weight ratio of the second organic solvent to water in the second evaporation feed is R23, wherein the weight/weight ratio of the second organic solvent to water in the azeotrope is R22 and wherein R23 is greater than R22 by at least 10%.
• the method further comprises the steps of condensing the vapors in the second vapor phase to form two phases, a second organic solvent-rich one and a first water-rich one, separating the phases, using the second organic solvent-rich phase in step (iii), and using the first water- rich phase for generating the hydrolysis medium.
• the method further comprises the step of spray drying the viscous fluid to form a de-acidified solid carbohydrate composition.
• the weight/weight ratio of HCI to carbohydrates in the de-acidified solid carbohydrate composition is less than 0.03.
• the hydrolyzing forms a hydrolyzate
• forming the first aqueous solution comprises separating a portion of the HCI from the hydrolyzate to form a first separated HCI stream and an HCI- depleted hydrolyzate and wherein the first separated HCI stream is used for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the hydrolyzate are W4, P4 and C4, respectively and the amount, the purity and the concentration of HCI in the first separated HCI stream are W5, P5 and C5, respectively and wherein W5/W4 is greater than 0.1 , P5/P4 is greater than 1.8, and C5/C4 is greater than 1.8.
• the method further comprises the steps of separating another portion of HCI from the HCI-depleted hydrolyzate to form a second separated HCI stream and using the second separated HCI stream for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the second separated HCI stream are W7, P7 and C7, respectively and wherein W7/W4 is greater than 0.1 , P7/P4 is greater than 1.8, and C7/C4 is greater than 0.4.
• the present invention provides, according to a sixth aspect, a method for the production of lignin comprising
• the weight/weight ratio of the first organic solvent to water in the first evaporation feed is R13, wherein the weight/weight ratio of the first organic solvent to water in the azeotrope is R12 and wherein R13 is greater than R12 by at least 10%.
• the method further comprises the steps of condensing the vapors in the first vapor phase to form two phases, a first organic solvent-rich one and a second water-rich one, separating the phases, using the first organic solvent-rich phase in step (iii), and using the second water-rich phase for generating the hydrolysis medium.
• the method further comprises a step of treating the lignin composition to effect at least one of deacidification and solvent removal.
• the treating comprises at least one of neutralizing a residual amount of HCI, centrifugation, displacement of residual solvent with water and drying.
• hydrolyzing forms an HCI-comprising lignin stream, wherein forming the second lignin stream comprises separating HCI from the HCI-comprising lignin stream to form a third separated HCI stream and an HCI-depleted lignin stream and wherein the third separated HCI stream is used for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the HCI-comprising lignin stream are W8, P8 and C8, respectively the amount, the purity and the concentration of HCI in the third separated HCI stream are W9, P9 and C9, respectively and wherein W9/W8 is greater than 0.1 , P9/P8 is greater than 1.1 , and C9/C8 is greater than 1.8,
• the method further comprises the steps of separating HCI from the HCI-depleted lignin stream to form a fourth separated HCI stream and using the fourth separated HCI stream for generating the hydrolysis medium.
• the amount of HCI in the fourth separated HCI stream is W10 and wherein W10/W8 is greater than 0.1.
• the present invention provides, according to a seventh aspect, a method for processing a lignocellulosic material and for the production of a carbohydrate composition comprising:
• (c2) having a solubility in water of less than 15%, and forming a heterogeneous azeotrope with water wherein the weight/weight ratio of the second organic solvent to water is in the range of between 5 and 0.2, and wherein the solubility of water in the organic solvent is less than 20%
• the hydrolysis medium is made with a recycled reagent HCI stream, wherein HCI purity and concentration are P6 and C6, respectively and wherein P6 is greater than 80% and C6 is greater than 30% (as calculated by 100 time HCI weight divided by the combined weights of HCI and water),
• the weight/weight ratio of thethe second organic solvent to water in the second evaporation feed is R23, wherein the weight/weight ratio of the second organic solvent to water in the azeotrope is R22 and wherein R23 is greater than R2 by at least 10%.
• the method further comprises the steps of condensing the vapors in the second vapor phase to form two phases, a second organic solvent-rich one and a first water-rich one, separating the phases, using the second organic solvent-rich phase in step (iii), and using the first water-rich phase for generating the hydrolysis medium.
• the viscous fluid comprises oligomers
• the method further comprises at least one of HCI hydrolysis of the oligomers, enzymatic hydrolysis of the oligomers, fermentation of the carbohydrates and simultaneous saccharification and fermentation of the oligomers.
• the method further comprises the step of spray drying the viscous fluid to form a de-acidified solid carbohydrate composition.
• the weight/weight ratio of HCI to carbohydrates in the de-acidified solid carbohydrate composition is less than 0.03.
• the de-acidified solid carbohydrate composition comprises oligomers
• the method further comprises at least one of acid hydrolysis of the oligomers, enzymatic hydrolysis of the oligomers, fermentation of the carbohydrates and simultaneous saccharification and fermentation of the oligomers.
• the method further comprises a step of treating the lignin composition to effect at least one of deacidification and solvent removal.
• the treating comprises at least one of neutralizing a residual amount of HCI, displacement of residual solvent with water, centrifugation and drying.
• the weight/weight ratio of the first organic solvent to water in the first evaporation feed is R13, wherein the weight/weight ratio of the first organic solvent to water in the azeotrope is R12 and wherein R13 is greater than R12 by at least 10%.
• the method further comprises the steps of condensing the vapors in the first vapor phase to form two phases, a first organic solvent-rich one and a second water-rich one, separating the phases, using the first organic solvent-rich phase in step (v) and using the second water- rich phase for generating the hydrolysis medium ⁇
• the hydrolyzing forms a hydrolyzate
• forming the first aqueous solution comprises separating a portion of the HCI from the hydrolyzate to form a first separated HCI stream and an HCI-depleted hydrolyzate and wherein the first separated HCI stream is used for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the hydrolyzate are W4, P4 and C4, respectively
• the amount, the purity and the concentration of HCI in the first separated HCI stream are W5, P5 and C5, respectively, and wherein W5/W4 is greater than 0.1 , P5/P4 is greater than 1.8, and C5/C4 is greater than 1.8.
• the method further comprises the steps of separating another portion of HCI from the HCI-depleted hydrolyzate to form a second separated HCI stream, and using the second separated HCI stream for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the second separated HCI stream are W7, P7 and C7, respectively, and wherein W7/W4 is greater than 0.1 , P7/P4 is greater than 1.8, and C7/C4 is greater than 0.4.
• the hydrolyzing forms an HCI- comprising lignin stream
• forming the second lignin stream comprises separating HCI from the HCI-comprising lignin stream to form a third separated HCI stream and an HCI-depleted lignin stream and wherein the third separated HCI stream is used for generating the hydrolysis medium.
• the amount, the purity and the concentration of HCI in the HCI- comprising lignin stream are W8, P8 and C8, respectively
• the amount, the purity and the concentration of HCI in the third separated HCI stream are W9, P9 and C9, respectively, and wherein W9/W8 is greater than 0.1
• P9/P8 is greater than 1.1
• C9/C8 is greater than 1.8.
• the method further comprises the steps of separating HCI from the HCI-depleted lignin stream to form a fourth separated HCI stream, and using the fourth separated HCI stream for generating the hydrolysis medium.
• the amount of HCI in the fourth separated HCI stream is W10 and wherein W10/W8 is greater than 0.1.
• the first organic solvent and the second organic solvent are of essentially the same chemical composition.
• the first organic solvent is of essentially the same composition as the second organic solvent.
• the method for the production of carbohydrate comprises (i) providing a lignocellulosic material feed comprising a polysaccharide and lignin; (ii) hydrolyzing the polysaccharide in an HCI-comprising hydrolysis medium to form a first aqueous solution comprising carbohydrates, HCI and water, wherein carbohydrates to water weight/weight ratio is in the range between 0.4 and 3 and wherein HCI/water weight/weight ratio is in the range between 0.17 and 0.50; and a second lignin stream comprising lignin, HCI and water, wherein lignin to water weight/weight ratio is in the range between 0.1 and 2.0 and wherein HCI/water weight/weight ratio is in the range between 0.15 and 1 ; (iii) contacting the first aqueous solution with an organic solvent to form a second evaporation feed, which solvent forms with water a heterogeneous azeotrope and is characterized by at least one of (a) having
• the invention also provides, a hetro-oligosaccharides composition comprising tetramers composed of glucose and at least two sugars selected from the group consisting of mannose, xylose, galactose, arabinose and fructose.
• the present invention further comprises combining at least portions of multiple HCI-comprising streams to reform a recycled HCI reagent stream.
• the combining is of at least two HCI- comprising streams selected from the group consisting of the first separated HCI stream, the second separated HCI stream, the third separated HCI stream, the fourth separated HCI stream, the first water rich phase and the second water-rich phase.
• W6/W4 is greater than 1 , preferably at least 1.2, more preferably at least 1.5 and most preferably at least 1.8.
• P6 is greater than 80%, preferably greater than 85%, more preferably greater than 90% and most preferably greater than 95%.
• C6 is greater than 30%, preferably greater than 35%, more preferably greater than 38% and most preferably greater than 40% (as calculated by 100 time HCI weight divided by the combined weights of HCI and water).
• the present invention further provides, according to an eighth aspect a tetramers composition
• a tetramers composition comprising hetro-oligosaccharides with a degree of polymerization of at least tetramers, which tetramers are composed of glucose and at least one sugar selected from the group consisting of mannose, xylose, galactose, arabinose and fructose, preferably at least two sugars from that list and more preferably at least three sugars from said list.
• the composition comprises at least two types of hetro-tetramers, each one of which is composed of glucose and at least one sugar selected from the group consisting of mannose, xylose, galactose, arabinose and fructose, preferably at least two sugars from said list.
• said tetramers composition is essentially HCI free.
• hetro- oligosaccharides as used here, means oligosaccharides composed of at least two different sugars.
• FIG. 1 is a flow diagram of a preferred embodiment of the present invention.
• the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of one of the methods of the invention.
• a polysaccharide in a polysaccharide-comprising feed ( ⁇ ps> in Fig. 1 ) is hydrolyzed in an HCI-comprising hydrolysis medium (hydrolysis takes place in [(ii)]).
• acid hereinafter means HCI.
• the polysaccharide-comprising feed is a lignocellulosic material, also referred to herein as a lignocellulosic material feed or lignocellulosic feed.
• HCI concentration in the hydrolysis medium is greater than 30%.
• the hydrolysis medium is formed, according to an embodiment, by contacting the lignocellulosic feed with a recycled reagent HCI stream ⁇ rg6>.
• the concentration and purity of HCI are C6 and P6, respectively.
• P6 is greater than 80%, preferably greater than 85%, more preferably greater than 90% and most preferably greater than 95%.
• C6 is greater than 30%, preferably greater than 35%, more preferably greater than 38% and most preferably greater than 40% (as calculated by 100 time HCI weight divided by the combined weights of HCI and water), According to one embodiment, that contacting operates in a batch mode, while according to another it is a continuous mode.
• contacting is conducted a counter-currently, e.g. in a tower reactor into which, according to one embodiment, the lignocellulosic feed is introduced from top and the recycled reagent HCI stream flows in from the bottom.
• the recycled reagent HCI stream comes in containing essentially no carbohydrates.
• carbohydrates from polysaccharides hydrolysis start to build up in it.
• the lignocellulosic material looses its polysaccharides, as it moves downwards counter-currently to the recycled reagent HCI stream.
• the lignocellulosic material is fed into a series of N reactors - numbered for the purpose of the explanation herein - as Di to D N (wherein reactors D-i to D N are not shown in Figure 1).
• the recycled reagent HCI stream is introduced into D N for a contact of a selected residence time.
• it is separated and moved to reactor D N _i for an additional contact of a selected residence time, after which it is moved to D N -2, etc.
• it is moved into reactor Di for a contact of a selected time with a fresh lignocellulosic solid material.
• the fresh solid material is contacted first with an aqueous HCI solution that was previously contacted N-1 times.
• the aqueous HCI solution is removed from the reactor and the solid material is contacted again with an aqueous HCI solution, this time with one that was previously contacted N-2 times. Finally, the solid material is contacted with a fresh recycled reagent HCI stream at the end of which the residual solid is separated and removed from the reactor. The emptied reactor is then re-filled with fresh lignocellulosic material and goes again through the series of contacts (starting with contact with an aqueous HCI solution that was previously contacted N-1 times). According to a preferred embodiment, while the aqueous HCI solution moves from one reactor to the other, the solid material stays in the same reactor for N contacts, after which it is removed.
• saccharide, sugar and carbohydrates are used herein interchangeably.
• Any polysaccharide is suitable, e.g. polymers of the monomers glucose, xylose, arabinose, mannose, galactose, and/or their combination.
• the monomers of interest are typically of either 6 carbon sugars (hexoses) or 5 carbon sugars (pentoses).
• glucose and dextrose are used herein interchangeably.
• the polymers could be homogenous (composed of only one type of carbohydrate) or heterogeneous (comprised of different carbohydrates) e.g. hemicellulose consisting mainly of xylose and arabinose or glucomannane consisting mainly of glucose and mannose.
• Various polysaccharides are suitable for the method of the present invention. Of particular interest are cellulose and hemicellulose.
• Any polysaccharide-comprising feed is suitable, particularly ones that which comprises cellulose, e.g. recycled paper, co-products of the pulp and paper industry and biomass cell walls.
• lignocelluiosic materials are lignocelluiosic materials.
• lignocelluiosic material refers to any material comprising cellulose and lignin.
• lignocelluiosic material further comprises hemicellulose, additional components such as extractives and mineral compounds.
• the weight ratios between the various components - mainly the three major ones, i.e. cellulose, hemicellulose and lignin - change according to the source of the lignocelluiosic material. The same is true for the content of mineral compounds, also referred to as ashes, and for the extractives.
• extractives means oil-soluble compounds present in various lignocelluiosic feeds, e.g. tall oils.
• lignocelluiosic materials are known and are suitable for the present invention.
• wood, wood-processing co- products such as wood chips from the boards industry, agricultural residues such as stover and corn cobs, sugar cane bagasse, switch grass and other energy crops, and various combinations of those.
• Lignocelluiosic material could be used as such and or after some pre-treatment. Any pre-treatment that does not lead to the hydrolysis of the majority of the cellulose content is suitable.
• the lignocelluiosic material is dried prior to the combining with the recycled reagent HCI stream.
• Lignocelluiosic material may be obtained from various sources at various degrees of moisture. Various methods of drying may be suitable. Preferably, drying is adapted to moisture contents lower than 10%w.
• the lignocelluiosic material is comminuted prior to the combining with the recycled reagent HCI stream.
• the lignocellulosic material is pre-treated for the removal and/or for the hydrolysis of hemicellulose prior to the combining with the recycled reagent HCI stream.
• Such removal and/or hydrolysis could be conducted by various means, e.g. elevated temperature treatment with water/steam and/or with dilute HCI solution, enzymatic hydrolysis, etc.
• Such treatments extract hemicellulose into an aqueous phase, hydrolyzes hemicellulose into water soluble sugars and combinations of those, leading to lignocellulosic material wherein cellulose is the main polysaccharide.
• the polysaccharides of the lignocellulosic material are not hydrolyzed, nor extracted prior to the combining with the recycled reagent HCI stream.
• the lignocellulosic material is pre-treated by at least one of steam explosion, ammonia explosion and delignification.
• the hydrolysis in [(ii)] of Fig. 1 is mainly of cellulose. According to the embodiment wherein there is no pre- hydrolysis or extraction of hemicellulose, both hemicellulose and cellulose are hydrolyzed in [(ii)]. HCI acts as a catalyst and is not consumed, except possibly for neutralizing basic components of the lignocellulosic material.
• At least 70%wt of the polysaccharides in the feed material hydrolyze into soluble carbohydrates, preferably more than 80%, more preferably more than 90%, and most preferably more than 95%.
• hydrolysis forms soluble carbohydrates. Accordingly, the concentration of the soluble carbohydrates in the medium increases with the progress of the hydrolysis reaction.
• the fresh lignocellulosic material is contacted several times with an HCI solution, which leads to an increased degree of hydrolysis of its polysaccharides content.
• essentially all the polysaccharides content of a lignocellulosic material feed is hydrolyzed into soluble carbohydrates, while the lignin content stays essentially insoluble.
• the removed insoluble lignin is in the form of solid dispersion in an HCI solution or as a wet cake wetted by such solution. That removed composition forms, according to an embodiment, a HCI-comprising lignin stream of the present invention ( ⁇ lg8> in Fig. 1 ).
• HCl amount, concentration and purity are W8, C8 and P8, respectively.
• the aqueous solution is removed from Di (not shown) which is a component of [(ii)] in Figure 1 , and used to form a first aqueous solution comprising carbohydrates, HCl and water.
• Di is a component of [(ii)] in Figure 1
• the removed aqueous solution is also referred to as a hydrolyzate ( ⁇ hy4> in Fig. 1 ).
• first aqueous solution carbohydrates to water weight/weight ratio is in the range between 0.4 and 3.0, preferably between 0.7 and 2.8, more preferably between 1 .0 and 2.5 and most preferably between 1 .5 and 2.2 and the HCI/water weight/weight ratio is in the range between 0.1 7 and 0.5, preferably between 0.20 and 0.40 and more preferably between 0.25 and 0.35.
• this first aqueous solution is a product of further treating the formed hydrolyzate, as further described in the following.
• HCl amount, concentration and purity are W4, C4 and P4, respectively.
• the hydrolyzate is essentially solids free.
• the hydrolyzate comprises solids and those are separated by at least one of filtration and centrifugation.
• the carbohydrate concentration in ⁇ hy4> is greater than 15%wt (as calculated by 100CH/(CH+W) , where CH and W are the weights of the carbohydrates and the water, respectively), preferably greater than 20% wt, more preferably greater than 25%wt, and most preferably greater than 30%wt.
• W4 is in many cases smaller than the amount of HCl in the recycled HCl reagent (W6), since part of the acid is contained in ⁇ lg8>.
• C4 is similar in size to HCl concentration in that reagent (C6), but typically somewhat smaller.
• P4 is between 20% and 70%, more preferably between 30% and 60%.
• the hydrolysis and the contacting of the present method are conducted in a continuous mode. In that case, amounts of stream and of components are presented in terms of flow rate, e.g. as the ratio between the flow rate of HCI and that of the initial lignocellulosic material feed in the hydrolysis medium. According to a preferred embodiment, that weight/weight ratio is between 0.2 and 5, preferably between 0.5 and 3.
• the concentration of a component in a medium is presented in weight percent (%wt) calculated from the weight (or flow rate) of the component in that medium and the combined weights (flow rates) of that component and the water in that medium.
• %wt weight percent
• the concentration of HCI according to the presentation herein is 40%.
• the concentration is on an "as is" basis, i.e. calculated from the weight (flow rate) of the component in that medium divided by the total weight (flow rate) of the medium.
• the purity of a component in a medium is the purity in a homogeneous phase (liquid or gas).
• the purity referred to is that in the solution that would form on separation of those insolubles.
• the purity is calculated on a water-free (or solvent-free) and weight basis.
• HCI purity in a solution composed of 50Kg water, 20Kg of HCI, 20Kg of carbohydrate and 10Kg mineral salt, as presented here is 40%.
• the lignocellulosic feed further comprises an organic compound, e.g. tall oil, and a fraction of the organic compound is dissolved in the formed hydrolyzate.
• the organic compound -comprising hydrolyzate is brought into contact at a temperature T3 with a third organic solvent, whereupon the organic compound selectively transfers to the third organic solvent to form an organic compound- depleted hydrolyzate and a first organic compound-carrying solvent.
• the first organic compound-carrying solvent has a commercial value as such.
• the method further comprises a step of recovering the third organic solvent and organic compound from the first organic compound-carrying solvent to form a separated organic compound and a regenerated third organic solvent.
• Various methods are suitable for such recovering, including distilling the third organic solvent and extracting it into another solvent, wherein the organic compound has limited miscibility.
• the organic compound is a tall oil.
• the separated organic compounds formed according to the present invention differ in composition from present commercial products and is of higher quality. Without wishing to be limited by theory, that could be the results of recovery in an acidic medium and/or of fractionation between the various streams of the process.
• the organic compounds extracted from the hydrolyzate can be enriched in components, which at high HCI concentration (typically greater than 30%), dissolve in the aqueous medium, rather than adsorb on the solid lignin product of hydrolysis.
• the contacting of the hydrolyzate with the third organic solvent is conducted while the hydrolyzate is high in HCI concentration, e.g. while the HCI concentration there is at least 25%, preferably at least 28% and more preferably at least 32%.
• the contacting is conducted prior to the following step of separating a portion of the HCI in the hydrolyzate.
• the inventors have found that the solubility of some of those organic compounds in the hydrolyzate decreases with decreasing HCI concentration.
• Contacting with the third organic solvent while HCI concentration is still high provides for high yield of recovering organic compounds on one hand and avoids their precipitation in the next step, which precipitation may form undesired coating of equipment.
• the method of the presented invention further comprises a step [C] of separating a portion of the HCI from the hydrolyzate to form a first separated HCI stream ⁇ 1 s5> wherein HCI amount, concentration and purity are W5, C5 and P5, respectively, and an HCI-depleted hydrolyzate ⁇ dh>.
• the separation involves distilling HCI out of the hydrolyzate and the first separated HCI stream ⁇ 1 s5> is gaseous.
• a significant fraction of the HCI in the hydrolyzate is distilled out in [C], so that W5/W4 is greater than 0.1 , preferably greater than 0.2, more preferably greater than 0.25 and most preferably greater than 0.3.
• the first separated HCI stream may contains small amounts of water, e.g. water vapors in a gaseous first separated HCI stream, and possibly also small amounts of some other volatile components of the hydrolyzate.
• both C5 and P5 are high, typically greater than 90%, preferably greater than 95% and more preferably greater than 97%.
• P5/P4 is greater than 1.8, preferably greater than 2.0, more preferably greater than 2.2 and most preferably greater than 2.5.
• C5/C4 is greater than 1.8, preferably greater than 2.0, more preferably greater than 2.2 and most preferably greater than 2.5.
• the method further comprises a step [I] of separating another portion of HCI from the HCI-depleted hydrolyzate to form a second separated HCI stream ⁇ 2s7> wherein HCI amount, concentration and purity are W7, C7 and P7, respectively, and a further-depleted hydrolyzate, which according to some embodiments, forms the first aqueous solution of the present invention ( ⁇ as1 > in Fig. 1).
• the separation in [I] involves distilling HCI out of the HCI-depleted hydrolyzate and the second separated HCI stream is gaseous.
• a significant fraction of the HCI in the HCI-depleted hydrolyzate is distilled out in [I], so that W7/W4 is greater than 0.1 , preferably greater than 0.2, more preferably greater than 0.3 and most preferably greater than 0.4.
• the second separated HCI stream is, according to a preferred embodiment a water-HCI azeotrope so that C7 is about azeotropic.
• the second separated HCI stream ⁇ 2s7> is essentially carbohydrates free, but may contain small amounts of volatile components of the hydrolyzate.
• P7 is high, typically greater than 90%, preferably greater than 95% and more preferably greater than 97%.
• P7/P4 is greater than 1.8, preferably greater than 2.0, more preferably greater than 2.2 and most preferably greater than 2.5.
• C7/C4 is greater than 0.4, preferably greater than 0.5, more preferably greater than 0.6, and most preferably greater than 0.7.
• the separating in [I] involves distilling HCI and the second separated HCI stream is of azeotropic concentration. It is important to note that, according to a preferred embodiment, distilling herein and optionally other distillation steps in the method of the present invention are conducted at sub-atmospheric pressure in order to maintain low distillation temperature so that undesired degradation of carbohydrates is avoided.
• the composition of the azeotrope changes with the distillation temperature.
• azeotropic composition refers to the composition of the azeotrope at the conditions - including temperature and pressure - of the distillation.
• azeotropic composition is also affected by the presence of other solutes in the solution.
• the azeotropic composition of the second separated HCI stream may vary with the concentration of carbohydrates in the distilled solution.
• the carbohydrates concentration in ⁇ dh> is in the range between 20% and 40% and that concentration in ⁇ as1 > is greater than that in ⁇ dh> by at least 50%.
• the carbohydrates concentration in ⁇ as1 > is greater than 30%wt, preferably greater than 40%wt, more preferably greater than 50%wt and most preferably greater than 55%wt.
• HCI/carbohydrates weight/weight ratio is about 1 or greater than 1.
• the distillations in [C] and [I] remove together about 50% - 70% of that initial HCI content and about a similar proportion of the initial water content there. In order to approach full recovery of the acid, the rest of the acid in that stream should be removed. Spray drying is not an economically viable option. On large industrial scale, e.g. about lOOtons carbohydrates per hour, the amounts of water and acid to be distilled would make spray drying of ⁇ as1 > highly expensive in both capital and operating cost.
• the inventors of the present invention have found a way to further remove acid and water from ⁇ as1 >, while forming a stream that is still fluid enough to be spray dried.
• the hydrolyzate, the depleted hydrolyzate, the further depleted hydrolyzate or the first aqueous stream ( ⁇ as1 > in Fig. 1) is contacted ([(iii)] in Fig. 1) with a second organic solvent ⁇ 2os> to form a second evaporation feed ⁇ 2ef>.
• water, HCI and the second organic solvent are distilled ([(iv)] in Fig. 1) from the second evaporation feed at a temperature below 100°C and at a pressure below 1atm, whereupon a second vapor phase ( ⁇ 2vp> in Fig. 1 ) and a viscous fluid ( ⁇ vf> in Fig. 1 ) are formed.
• at least one of the temperature and the pressure vary during the distillation operation, but during at least a fraction of the distillation time, temperature is below 100°C and pressure is below 1 atm.
• the HCI-depleted hydrolyzate, the further depleted hydrolyzate or the first aqueous stream when combined with the second solvent, carbohydrates to water weight/weight ratio is in the range between 0.4 and 3.0, preferably between 0.7 and 2.8, more preferably between 1.0 and 2.5 and most preferably between 1.5 and 2.2 and the HCI/water weight/weight ratio is in the range between 0.17 and 0.5, preferably between 0.20 and 0.40 and more preferably between 0.25 and 0.35.
• organic solvent and “solvent” are used here interchangeably.
• the first organic solvent and the second organic solvent of the present invention are characterized by forming with water a heterogeneous binary azeotrope to be distinguished from a homogeneous binary azeotrope.
• a heterogeneous binary azeotrope to be distinguished from a homogeneous binary azeotrope.
• two compounds (A and B) form a binary homogeneous azeotrope
• at the azeotropic composition there is a single liquid phase with a given A/B ratio and when vapors distilled out of it, they contain A and B at the same A/B ratio. Therefore, distillation does not change the composition of the liquid phase.
• the second organic solvent and water are of limited mutual solubility.
• the solubility of the second organic solvent in water is less than 15%wt, preferably less than 10%wt, more preferably less than 5% and most preferably less than 1 %.
• the solubility of water in the second organic solvent is less than 20%wt, preferably less than 15%wt, more preferably less than 10% and most preferably less than 8%.
• the second organic solvent to water weight/weight ratio is in the range between 5 and 0.2, preferably between 4 and 0.25, more preferably between 3 and 0.3, and most preferably between 2 and 0.5.
• Solubility data is presented herein as the concentration of the solute in a saturated solvent solution at 25°C.
• solvent solubility in water of 10%wt means that the concentration of the solvent in its saturated aqueous solution at 25°C is 1 0%wt.
• the second organic solvent is characterized by having polarity related component of Hoy's cohesion parameter between 0 and 15MPa /2 , preferably between 4MPa 1/2 and 12MPa 1/2 and more preferably between 6MPa 2 and 10MPa /2 .
• the second organic solvent is characterized by having Hydrogen bonding related component of Hoy's cohesion parameter between 0 and 20MPa /2 , preferably between 1 MPa /2 and 15MPa 1/2 and more preferably between 2MPa /2 and 14MPa 1/2 .
• the cohesion parameter or solubility parameter was defined by Hildebrand as the square root of the cohesive energy density:
• the second organic solvent has a boiling point at 1 atm in the range between 100°C and 200°C, preferably between 1 10°C and 190°C, more preferably between 120°C and 180°C and most preferably between 130°C and 160°C.
• the second organic solvent is selected from the group consisting of C 5 -C 8 alcohols or chlorides (including primary, secondary, tertiary and quaternary ones, including aliphatic and aromatic ones and including linear and branched ones), toluene, xylenes, ethyl benzene, propyl benzene, isopropyl benzene and nonane.
• the viscous fluid formed in [(iv)] comprises at least one carbohydrate, water, HCI and optionally also the second solvent.
• the viscous fluid is homogeneous according to one embodiment and heterogeneous according to another.
• the viscous fluid is heterogeneous and comprises a continuous phase and a dispersed phase, in which within the dispersed phase the major component is the second solvent, according to one embodiment, and solid carbohydrate according to another.
• the viscous fluid comprising at least 75% carbohydrates, preferably at least 80%, more preferably at least 83% and most preferably at least 86% as calculated by 100CH/(CH+W), wherein CH is the amount of carbohydrates and W is the amount of water.
• the majority of the carbohydrates in the viscous fluid are the products of hydrolyzing the polysaccharides of the polysaccharide comprising feed to hydrolysis ( ⁇ ps>), typically a lignocellulosic material.
• carbohydrates from other sources are combined with those products of hydrolysis to form the second evaporation feed and end up in the viscous fluid.
• the viscous fluid comprises carbohydrates formed in isomerization of other carbohydrate, e.g. fructose formed from glucose.
• the carbohydrates in the viscous solution are monomers, dimmers, trimers, higher oligomers, and their combinations.
• Those monomers, dimmers, trimers, and/or higher oligomers comprise monomers selected from the group consisting of glucose, xylose, mannose, arabinose, galactose, other sugar hexoses, other pentoses and combinations of those.
• glucose is the main carbohydrate there.
• monomer is used here to describe both non- polymerized carbohydrates and the units out of which oligomers are formed.
• the water content of the viscous fluid is between 2%wt and 25%wt, preferably between 3%wt and 20% wt, more preferably between 4%wt and 18%wt and, most preferably between 5%wt and 15%wt.
• the HCI content of the viscous fluid is between 10%wt and 55%wt, preferably between 15% wt and 50%wt, more preferably between 18%wt and 40% wt and most preferably between 20%wt and 38%wt as calculated by 100HCI/(HCI+W), wherein HCI is the amount of HCI in the viscous fluid and W is the amount of water therein.
• the second organic solvent content of the viscous fluid is between 0%wt and 25%wt, preferably between 1 %wt and 20%wt, more preferably between 2%wt and 18%wt and most preferably between 3%wt and 15%wt.
• the HCI/water weight/weight ratio in the viscous fluid is in the range between 0.20 and 1.0, preferably between 0.3 and 0.9 and more preferably between 0.4 and 0.8.
• the carbohydrate/water weight/weight ratio in the viscous fluid is in the range between 2 and 20, preferably between 3 and 15, more preferably between 4 and 12 and most preferably between 5 and 11.
• the HCI/carbohydrate weight/weight ratio in the viscous fluid is in the range between 0.02 and 0.15, preferably between 0.03 and 0.12 and more preferably between 0.04 and 0.10.
• the hydrolyzate, the HCI-depleted hydrolyzate, the further depleted hydrolyzate or the first aqueous stream forms a second evaporation feed as such (with no addition of the second solvent).
• Water and HCI are distilled from the second evaporation feed at a temperature below 100°C and at a pressure below 1 atm, whereupon a second vapor phase and a viscous fluid are formed.
• the viscous fluid of this alternative embodiment comprises carbohydrates, HCI and water according to the above composition, but no solvent. According to a first modification, evaporation starts in the absence of a solvent, and the second organic solvent is added to the composition during evaporation.
• the viscous fluid comprises the second organic solvent according to the above composition.
• the combined acid removal in [C], [I] and [(iv)] is greater than 80% of the initial acid content of the hydrolyzate, preferably greater than 85%, more preferably greater than 90% and ,most preferably greater than 95%.
• the combined water removal in [C], [I] and [(iv)] is greater than 80% of the initial water content of the hydrolyzate, preferably greater than 85%, more preferably greater than 90% and ,most preferably greater than 95%.
• the formed viscous fluid ⁇ vf> is highly concentrated in carbohydrates. It was surprisingly found that ⁇ vf> is fluid enough to be spray dried.
• the viscosity of the viscous fluid is less than 150cP, preferably less than 120cP more preferably less than 100cP, and most preferably less than 90cP. It is not clear how was such fluidity maintained in the highly concentrated ⁇ vf>. Without wishing to be limited by theory, possible explanation to that could be some specific role the solvent plays in ⁇ vf> and/or the specific composition of the carbohydrate, e.g. the mix of carbohydrates it is made of and the degree and nature of oligomerization.
• the ratio between the amount of the first aqueous solution and the amount of the second organic solvent contacted with it in [(iii)] is such that solvent is found in the viscous solution at the end of the distillation.
• the solvent/water ratio in the viscous fluid is greater than the solvent/water ratio in the water-solvent heterogeneous azeotrope.
• the second organic solvent/water weight/weight ratio in the viscous fluid the second organic solvent/water weight/weight ratio is R2, the second organic solvent has heterogeneous azeotrope with water and the second organic solvent/water weight/weight ratio in the azeotrope is R22 and R2 is greater than R22 by at least 10%, preferably at least 25%, more preferably at least 40% and most preferably at least 50%.
• the second organic solvent/water weight/weight ratio in the second evaporation feed is R23
• the second organic solvent/water weight/weight ratio in the azeotrope is R22 and R23 is greater than R22 by at least 10%, preferably at least 25%, more preferably at least 40% and most preferably at least 50%.
• the second organic solvent used to form the second evaporation feed is not pure, e.g. contains water and or HCI.
• the used second organic solvent is recycled from another step in the process (e.g. from condensate of a distillation step).
• R23 refers to the ratio between the solvent on solutes free basis and water.
• R22 may depend on the temperature of distillation, on its pressure and on the content of the other components in the evaporation feed (including HCI and carbohydrates).
• R22 is referred to the second solvent/water weight/weight ratio in the solvent-water binary system.
• solvent/water ratio in the vapor phase may differ from that in the binary system. As indicated, that ratio may further depend on the carbohydrates concentration in the second evaporation feed.
• R22 refers to the solvent/water ratio in the vapor phase formed on distilling from the second evaporation feed.
• the method further comprising the steps of condensing the vapors in the second vapor phase (step [O] in Fig. 1) to form two phases, a second organic-rich one ( ⁇ 2osr> in Fig. 1) and a first water-rich one ( ⁇ 1 wr> in Fig. 1), using the second organic solvent-rich phase in the contacting step [(iii)] and using the first water-rich phase for generating the hydrolysis medium.
• Any method of condensing is suitable, preferably comprising cooling, pressure increase or both.
• the organic solvent-rich phase also comprises water and HCI and the water-rich one also comprises solvent and HCI. Any method of separating the phases is suitable, e.g. decantation.
• the second organic solvent-rich phase is used in step [(iii)] as is or after some treatment, e.g. removal of dissolved water, HCI or both.
• the first water-rich phase is used for regenerating the hydrolysis medium as is or after some treatment.
• the viscous fluid is further treated.
• such further treatment comprises removal of residual HCI to form a de-acidified carbohydrate.
• removal of residual HCI involves at least one of solvent extraction, membrane separation, ion- exchange and evaporation.
• the viscous solution is diluted prior to such removal of HCI, while according to others it is not.
• the residual HCI is removed by solvent extraction, using for that purpose the extractants as described in PCT/IL2008/000278, PCT/IL2009/000392 and Israel Patent Application No: 201 ,330, the relevant teachings of which are incorporated herein by reference.
• the second organic solvent is used as the extractant for the removal of the residual HCI.
• the method comprises removal of the residual HCI by distillation.
• distillation is conducted on the viscous fluid as such or after slight modifications, such as minor adjustment of the carbohydrate concentration and changing the amount of the second organic solvent therein. Such changes in the amount may comprise adding or removing such solvent.
• another solvent is added.
• the ratio between the second organic solvent in the viscous fluid and the water there is such that on azeotropic distillation of water and the solvent, essentially all the water is removed, while excess solvent remains. Such excess solvent is removed, according to an embodiment, by further distillation or in a separate operation.
• the method comprises the step of spray drying ([P]) the viscous fluid to form the de-acidified solid carbohydrate composition ( ⁇ dsc> in Fig. 1 ) and vapors of HCI, water and optionally the solvent.
• Spray drying conditions are adjusted, according to an embodiment, for removing essentially all the water from the viscous solution, while some of the second organic solvent may stay and be removed subsequently.
• the viscous fluid is sprayed, as such or after some modification into a hot vapor stream and vaporized. Solids form as moisture quickly leaves the droplets.
• a nozzle is usually used to make the droplets as small as possible, maximizing heat transfer and the rate of water vaporization.
• Droplet sizes range, according to an embodiment, from 20 to 180 pm depending on the nozzle.
• a dried powder is formed in a single step, within a short residence time and at a relatively low temperature, all of which minimize carbohydrates degradation.
• the hot and dried powder is contacted with water in order to accelerate cooling and to form an aqueous solution of the carbohydrate.
• residual second solvent is distilled out of that carbohydrates solution.
• the method of the present invention enables the removal of the majority of the acid at relatively low cost by combining distillation of HCI in [C] (as a nearly dry gas), in [I] (as a water-HCI azeotrope) and in [(iv)] (preferably as a mixture of HCI, water and second solvent vapors) and the efficient removal of the residual acid in spray drying. It was surprisingly found that residual HCI removal in spray drying is more efficient than suggested by the prior art.
• HCI/carbohydrates weight/weight ratio is less than 0.03, preferably less than 0.02, more preferably less than 0.01 and most preferably less than 0.005.
• At least 95% of the acid in the hydrolyzate is recovered, more preferably at least 96% and most preferably at least 98%.
• essentially all the HCI in the hydrolyzate is removed and an essentially a HCI-free carbohydrate stream is formed by a combination of distillation operations ([C], [I], [(iv)] and [P]) with no need for other acid removal means, such as solvent extraction or membrane separation.
• the viscous fluid and the de-acidified solid carbohydrate composition comprise carbohydrate resulting from the hydrolysis of the polysaccharides.
• the carbohydrates of the viscous fluid and/or of the de-acidified solid carbohydrate composition are of low degree of polymerization, e.g. monosaccharides, disaccharides and oligosaccharides (e.g.
• trimers and tetramers at various ratios depending on the parameters of the hydrolysis reaction (such as HCI concentration and residence time) and on the conditions used for the separation of the first separated HCI stream, for the separation of the second separated HCI stream (where applicable), for HCI and water (and second solvent) distillation from the second evaporation feed and in the spray drier (where applicable).
• the term oligosaccharide refers to dimmers, trimers, tetramers and other oligomers up to degree of polymerization of 10. According to an embodiment, essentially all the oligomers in the viscous fluid, in de-acidified solid carbohydrate composition, and/or in both are water soluble.
• the oligosaccharides of the viscous fluid and/or of the de-acidified solid carbohydrate composition are composed of multiple sugars.
• the oligosaccharides are composed of glucose and at least one sugar selected from the group consisting of mannose, xylose, galactose, arabinose and fructose, preferably at least two sugars from that least, more preferably at least three and most preferably at least four.
• the viscous fluid of the present invention, the de-acidified solid carbohydrate composition of the present invention or both are further converted into products, preferably selected from a group consisting of biofuels, chemicals and food ingredients.
• the further conversion comprises at least one of final purification, hydrolysis, carbohydrates fraction, dilution and re-concentration.
• the further conversion comprises oligomers hydrolysis, which hydrolysis uses according to various embodiment, at least one biological catalyst, at least one chemical catalysts and or a combination of both.
• the conversion involves fermentation to form fermentation products.
• the viscous fluid or the de-acidified solid carbohydrate composition is diluted prior to or simultaneously with application of a biological catalyst or of a chemical catalyst, or prior to fermentation.
• the viscous fluid, the de-acidified solid carbohydrate composition and or diluted solution thereof is converted as such. Alternatively, it is first pre- treated.
• pre-treating comprises at least one of adding a component (a nutrient according to an embodiment), removing a component (an inhibitor according to an embodiment), oligomers hydrolysis and combinations thereof.
• oligomers hydrolysis in the viscous fluid, the de-acidified solid carbohydrate composition and or diluted solution thereof involves a chemical catalysis, a biological catalysis and or a combination of those.
• HCI is used as a chemical catalyst.
• HCI is added for the catalysis, optionally from the process stream, such as the first separated HCI stream, the second separated HCI stream and the third separated HCI stream.
• the HCI-catalyzed hydrolysis is conducted prior to the removal of the residual HCI from the viscous fluid.
• such chemically catalyzed oligomers hydrolysis is conducted at a temperature in the range between 50°C and 130°C.
• the residence time for hydrolysis is between 1 min and 60min.
• oligomers hydrolysis involves an enzymatic hydrolysis.
• hydrolysis uses at least one enzyme with cellulose hydrolysis activity, at least one enzyme with hemicellulose hydrolysis activity, at least one enzyme with 1 -4 alpha bond hydrolysis activity, at least one enzyme with 1 -6 alpha bond hydrolysis activity, at least one enzyme with 1 -4 beta bond hydrolysis activity, at least one enzyme with 1-6 beta bond hydrolysis activity, and or combinations (cocktail) thereof.
• enzymes capable of operating at temperatures greater than 40°C, preferably greater than 50°C and more preferably greater than 60°C are adapted to be used.
• enzymes capable of operating at a carbohydrates concentration greater than 25%wt, preferably greater than 30%wt and more preferably greater than 35% wt are adapted to be used.
• at least one immobilized enzymes is adapted to be used for oligomers hydrolysis.
• multiple enzymes of the above list are immobilized and used in the converting.
• carbohydrates in the viscous fluid of the present invention, in the de-acidified solid carbohydrate composition of the present invention and or in a product of their dilution are further converted in a simultaneous saccharification and fermentation.
• simultaneous saccharification and fermentation means a treatment wherein oligomers hydrolysis and fermentation of hydrolysis products (optionally combined with fermentation of oligomers, e.g. dimmers and trimers) are conducted simultaneously.
• the hydrolysis and the fermentation are conducted in the same vessel.
• the simultaneous saccharification and fermentation conversion uses at least one enzyme with cellulose hydrolysis activity, at least one enzyme with hemiceliulose hydrolysis activity, at least one enzyme with 1 -4 alpha bond hydrolysis activity, at least one enzyme with 1 -6 alpha bond hydrolysis activity, at least one enzyme with 1 -4 beta bond hydrolysis activity, at least one enzyme with 1 -6 beta bond hydrolysis activity, and or combinations thereof.
• at least one immobilized enzymes is adapted to be used in the simultaneous saccharification and fermentation.
• multiple enzymes of the above list are immobilized and used in the converting.
• the fermentation is to form a renewable fuel, such as ethanol, butanol and or a fatty acid ester and or a precursor of a renewable fuel, such as iso-butanol, and the like.
• the fermentation is to form food or feed ingredient, such as citric acid, lysine, mono- sodium glutamate, and the like.
• the fermentation is to form an industrial product, such as a monomer for the polymers industry (e.g. lactic acid), a chemical for use as such or a precursor of such chemical, and the like.
• hydrolysis forms the HCI-comprising lignin stream comprising lignin, HCI and water ( ⁇ lg8> in Fig. 1).
• HCI amount, concentration and purity are W8, C8 and P8, respectively.
• a major fraction of the HCI in the HCI reagent stream ends up in the HCI-comprising lignin stream, so that W8/W6 is greater than 30%, preferably greater than 38% and more preferably greater than 45%.
• the method of the present invention enables the recovery of essentially all the acid in that stream and obtaining it at high concentration to minimize re- concentration costs.
• HCI separation from the HCI comprising lignin stream is done with no or with only a minimal wash with water.
• the lignocellulosic feed further comprises an organic compound, e.g. tall oil, and a fraction of the organic compound ends up in the HCI-comprising lignin stream.
• the HCI- comprising lignin stream is brought into contact with a fourth organic solvent, whereupon the organic compound selectively transfers to the fourth organic solvent to form an organic compound-depleted lignin stream and a second organic compound-carrying solvent.
• the second organic compound-carrying solvent has a commercial value as such.
• the method further comprises a step of recovering the fourth organic solvent and organic compound from the second organic compound-carrying solvent to form a separated organic compound and regenerated the fourth organic solvent.
• the organic compound is a tall oil.
• a third organic solvent is used to extract organic compounds from the hydrolyzate, a fourth organic compound is used to extract organic compounds form the HCI-comprising lignin stream and the third organic solvent and the fourth organic solvent are of essentially the same composition.
• the first organic compound-carrying solvent and the second organic compound-carrying solvent are combined to form a combined organic compound- carrying solvent and the organic compound is separated from the combined organic compound carrying solvent.
• the term of essentially the same composition for two components means that the two are composed of the same compound in case each of those is composed of a single compound, or, in case of mixtures, that at least 50%wt. of the composition of one component is identical to at least 50%wt. of the composition of the other component. That is, for example the case wherein the two components are mixtures of hydrocarbons (e.g. C6 to C9 ones) and wherein at least 50%wt. of each mixture is the same hydrocarbon, e.g. heptane.
• the third organic solvent, the fourth organic solvent or both are selected from the group consisting of heptanes, octanes and nonanes, and most preferably heptanes.
• the method comprises a step of forming a second lignin stream from the HCI-comprising lignin stream, which the second lignin stream is characterized by lignin to water weight/weight ratio is in the range between 0.1 and 2, preferably between 0.3 and 1.8, more preferably between 0.5 and 1.5 and most preferably between 0.8 and 1.2.
• the second lignin stream is further characterized by HCI/water weight/weight ratio in the range between 0.15 and 1 , preferably between 0.2 and 0.8, more preferably between 0.25 and 0.6 and most preferably between 0.3 and 0.5.
• the forming of the second lignin stream from the HCI-comprising lignin stream comprises separating ([D] in Fig. 1 ) HCI from the HCI-comprising lignin stream to form a third separated HCI stream ⁇ 3s9> wherein HCI amount, concentration and purity are W9, C9 and P9, respectively, and an HCI-depleted lignin stream ⁇ dl>.
• the separating comprises distillation and the third separated HCI stream is gaseous.
• at least a portion of the third separated HCI stream is used to form the recycled reagent HCI, e.g. by combining it with at least a portion of the first separated HCI stream.
• HCI streams of about azeotropic concentration are combined with the HCI-comprising lignin stream prior to the separation of the third separated HCI stream, e.g. by distillation.
• W9/W8 is greater than 0.1 , preferably greater than 0.2, more preferably greater than 0.3 and most preferably greater than 0.4.
• P9/P8 is greater than 1.1 , preferably greater than 1.2, more preferably greater than 1.3 and most preferably greater than 1.4.
• C5/C4 is greater than 1.8, preferably greater than 2.0, more preferably greater than 2.5 and most preferably greater than 3.0.
• the forming of the second lignin stream further comprises a step ([K] in Fig. 1) of separating HCI from the HCI-depleted lignin stream to form a fourth separated HCI stream ⁇ 4s10> wherein HCI amount is W10, and a further HCI-depleted lignin stream.
• W10/W8 is greater than 0.1 , preferably greater than 0.2, more preferably greater than 0.3 and most preferably greater than 0.4.
• the further HCI-depleted lignin stream forms the second lignin stream as such or after some modification.
• the separating HCI from the HCI-depleted lignin stream comprises at least one of filtration, press filtration and centrifugation.
• the filtration, press filtration or centrifugation forms a wet cake of relatively high dry matter content.
• the inventors have surprisingly found that the separating of residual aqueous HCI solution is markedly improved when conducted on the HCI-depleted lignin stream after separating the third separated HCI stream.
• the dry matter content of that formed cake is greater than 30%wt, preferably greater than 35%wt, more preferably greater than 38% and most preferably greater than 40% wt.
• the lignocellulosic feed further comprises an organic compound, e.g. tall oil, and a fraction of the organic compound ends up in the further HCI-depleted lignin stream or in the second lignin stream.
• that further HCI-depleted lignin stream or the second lignin stream is brought into contact with a fifth organic solvent, whereupon the organic compound selectively transfers to the fifth organic solvent to form an organic compound-depleted lignin stream and a third organic compound-carrying solvent.
• the third organic compound-carrying solvent has a commercial value as such.
• the method further comprises a step of recovering the fifth organic solvent and organic compound from the third organic compound-carrying solvent to form separated organic compound and regenerated fifth organic solvent.
• Various methods are suitable for such recovering, including distilling the fifth organic solvent and extracting it into another solvent, wherein the organic compound has limited miscibility.
• the organic compound is a tall oil.
• the fifth organic solvent is of essentially the same composition of the third organic solvent, is of the essentially the same composition of a fourth organic solvent or both.
• the third organic compound-carrying solvent is combined with the first organic compound-carrying solvent, and or with the second organic compound-carrying solvent to form a combination out of which the organic compound and the solvent are separated.
• the second lignin stream ( ⁇ 2I> in Fig. 1 ) is contacted ([(v)] in Fig. 1 ) with a first organic solvent ⁇ 1 os> to form a first evaporation feed ⁇ 1ef>.
• a first organic solvent ⁇ 1 os> to form a first evaporation feed ⁇ 1ef>.
• water, HCI and the first organic solvent are distilled ([(vi)] in Fig. 1 ) from the first evaporation feed at a temperature below 100°C and at a pressure below 1 atm, whereupon a first vapor phase ( ⁇ 1vp> in Fig. 1) and a lignin composition (( ⁇ lc> in Fig. 1) are formed.
• the first organic solvent of the present invention forms with water a heterogeneous azeotrope.
• the solubility of the first organic solvent in water is less than 15% wt, preferably less than 10%wt, more preferably less than 5% and most preferably less than 1%.
• the solubility of water in the first organic solvent is less than 20%wt, preferably less than 15%wt, more preferably less than 10% and most preferably less than 8%.
• the first organic solvent to water weight/weight ratio is in the range between 5 and 0.2, preferably between 4 and 0.25, more preferably between 3 and 0.3 and most preferably between 2 and 0.5.
• the first organic solvent is characterized by having polarity related component of Hoy's cohesion parameter between 0 and 15, preferably between 4 and 12 and more preferably between 6 and 10.
• the first organic solvent is characterized by having Hydrogen bonding related component of Hoy's cohesion parameter between 0 and 20, preferably between 1 and 15 and more preferably between 2 and 4.
• the first organic solvent has a boiling point at 1 atm in the range between 100°C and 200°C, preferably between 110°C and 190°C, more preferably between 120°C and 180°C and most preferably between 130°C and 160°C.
• the first organic solvent is selected from the group consisting of C5-C8 alcohols or chlorides (including primary, secondary, tertiary and quaternary ones, including aliphatic and aromatic ones and including linear and branched ones), toluene, xylenes, ethyl benzene, propyl benzene, isopropyl benzene and nonane.
• the evaporating in [(vi)] forms a lignin composition.
• the lignin composition of the present invention comprises between 10% wt and 50% wt lignin, preferably between 12%wt and 40%wt, more preferably between 14%wt and 30%wt and most preferably between 15%wt and 25%wt (unlike carbohydrates in the viscous fluid, lignin concentration is presented here on an as is basis).
• the lignin composition is essentially water free.
• the lignin composition comprises water, but at a concentration of less than 8%wt water, preferably less than 5%wt, more preferably less than 3%wt and most preferably less than 1 %wt.
• the lignin composition also comprises between 50%wt and 90%wt of a first solvent, preferably between 60%wt and 88%wt, more preferably between 70%wt and 85%wt and most preferably between 72%wt and 82%wt on an as is basis.
• the lignin composition also comprises, according to some embodiments HCI, the HCI concentration is less than 10%wt, preferably less than 8%wt, more preferably less than 6%wt and most preferably less than 4%wt (on an as is basis).
• the lignin composition further comprises at least one carbohydrate and the carbohydrate contents is less than 5%wt, preferably less than 4%wt, more preferably less than 3%wt and most preferably less than 2%wt (on an as is basis).
• the lignin composition comprises insoluble lignin dispersed in a liquid, preferably in a liquid solvent solution (which may contain few percents of aqueous solution dispersed in it).
• the lignin composition comprises a wet cake wherein lignin is wetted by such liquid solution.
• the lignin composition further comprises at least one of residual cellulose, a mineral salt and tall oils.
• the ratio between the amount of water in the second lignin stream and the amount of the first organic solvent contacted with it in [(v)] is such that solvent is found in the lignin composition at the end of the distillation.
• the solvent/water ratio in the lignin composition is greater than the solvent/water ratio in the water-solvent heterogeneous azeotrope.
• the first organic solvent to water weight/weight ratio is R1
• the first organic solvent has heterogeneous azeotrope with water and the first organic solvent/water weight/weight ratio in the azeotrope is R12 and R1 is greater than R12 by at least 10%, preferably at least 25%, more preferably at least 40%, and most preferably at least 50%.
• the first organic solvent/water weight/weight ratio in the first evaporation feed is R13
• the first organic solvent to water weight/weight ratio in the azeotrope is R12 and R13 is greater than R12 by at least 10%, preferably at least 25%, more preferably at least 40% and most preferably at least 50%.
• the first organic solvent used to form the first evaporation feed is not pure, e.g. containing water and or HCI.
• the used first organic solvent is recycled from another step in the process (e.g. from condensate of a distillation step).
• R13 refers to the ratio between the solvent on solutes-free basis and water.
• R12 may depend on the temperature of distillation, on its pressure and on the content of the other components in the evaporation feed (including HCI and carbohydrates).
• the solvent/water ratio in the first vapor phase may differ from that in the solvent-water binary system.
• R12 as used herein means the solvent/water ratio in the first vapor phase.
• the method further comprises the steps of condensing the vapors in the first vapor phase (step [Q] in Fig. 1 ) to form two phases, a first organic solvent-rich one ( ⁇ 1 osr> in Fig. 1 ) and a second water-rich one ( ⁇ 2wr> in Fig. 1), using the first organic solvent-rich phase in the contacting step [(v)] and using the second water-rich phase for generating the hydrolysis medium.
• Any method of condensing is suitable, preferably comprising cooling, and or pressure increase.
• the first organic solvent-rich phase also comprises water and HCI and the second water-rich one also comprising solvent and HCI.
• Any method of separating the phases is suitable, e.g.
• the first organic solvent-rich phase is used in step [(v)] as is or after some treatment, e.g. removal of the dissolved water, HCI or both.
• the second water-rich phase is used for regenerating the hydrolysis medium as is or after some treatment.
• the method of the present invention comprises further treating the lignin composition (step [R] in Fig. 1 ) to form a treated lignin composition ( ⁇ tlc> in Fig. 1 ).
• further treating comprises removal of residual HCI from the lignin composition, neutralization of the residual HCI there, desolventization and an additional purification.
• the desolventization comprises centrifugation.
• the desolventization comprises contacting the solvent-wetted lignin cake with water whereby water displaces solvent from the solvent wetted cake, followed by centrifugation.
• HCI concentration in the lignin composition, in the treated lignin composition ( ⁇ tlc> in Fig. 1) or in both is less than 10,000ppm, more preferably less than 5000ppm and most preferably less than 2000ppm.
• the first organic solvent is of essentially the same composition as the second organic solvent.
• the first vapor phase or its condensates is combined with the second vapor phase or its condensate for further treatment resulting in the formation of a water-rich phase to be used in regenerating the hydrolysis medium and an organic solvent-rich phase to be used in the contacting steps [(iii)] and [(v)].
• the method of the present invention further comprises combining (step [S] in Fig. 1 ) at least portions of multiple HCI-comprising streams to reform the recycled HCI reagent stream.
• the combining is of at least two HCI-comprising streams selected from the group consisting of the first separated HCI stream, the second separated HCI stream, the third separated HCI stream, the fourth separated HCI stream, the first water-rich phase and the second water-rich phase.
• the amount, concentration and purity of HCI in the recycled reagent HCI stream are W6, C6 and P6, respectively.
• W6/W4 is greater than 1 , preferably at least 1.2, more preferably at least 1.5 and most preferably at least 1.8.
• the weight/weight ratio between W6 and that of the initial polysaccharide-comprising feed in forming the hydrolysis medium is between 0.2 and 5 and preferably between 0.5 and 3.
• P6 is greater than 80%, preferably greater than 85%, more preferably greater than 90% and most preferably greater than 95%.
• C6 is greater than 30%, preferably greater than 35%, more preferably greater than 38% and most preferably greater than 40% (as calculated by 100 time HCI weight divided by the combined weights of HCI and water).
• formation of the recycled HCI reagent stream does not require water removal from an HCI-comprising stream.
• water removal from an HCI-comprising stream is limited to less than 0.1 ton of water per ton of HCI in the recycled reagent stream, preferably less than 0.05 ton, more preferably less than 0.03 ton and most preferably less than 0.01 ton.
• HCI HCI
• water CH
• the mixture was kept at 40°C for 3 hours, in which time oligomers are formed.
• the formed viscous fluid had HCI to carbohydrates weight/weight ratio of about 0.058, which represents HCI removal greater than 95% from a typical hydrolyzate, where HCI/carbohydrate weight/weight ratio is greater than 1. Its carbohydrate/water weight/weight ratio is about 10, representing removal of about 95% of the water in the hydrolyzate (where water/carbohydrate weight/weight ratio is greater than 2).
• the viscous fluid (as is, before the separation of the solvent) had at 80°C viscosity of about 80cP, low enough to be fed to a spray drier.
• the mixture was kept overnight at 34°C. 33.4gr of that first aqueous solution were combined in a flask with 8.0gr hexanol to form an evaporation feed. Evaporation was applied at 100-150mbar for about 1.5hr at a temperature that increased from 62°C at the beginning of the distillation to 75°C at its end.
• the distillate was cooled and collected to form an organic solvent-rich light phase (light) and an aqueous phase (heavy).
• the carbohydrates mixture contained glucose, fructose, xylose, arabinose and galactose at relative weights of 100, 1.25, 1 1.4, 3 and 4.8, respectively.
• the mixture was kept at 45°C for 2 hours, in which time oligomers are formed. 32.4gr of that first aqueous solution were combined in a flask with 6.23gr hexanol to form an evaporation feed.
• the viscosity of the viscous phase herein was lower than that in previous examples, where a single carbohydrate or two carbohydrates were tested.
• lignin solution 18.77gr lignin, 18.14gr HCI and 60.28gr water were mixed. The solution was combined in a flask with 243.2 gr of fresh hexanol. Distillation was applied at atmospheric pressure at about 102-103°C for 3 hours. The distillate was cooled and collected to form an organic solvent-rich light phase (light) and an aqueous phase (heavy). In the feed flask remained a lignin cake in a brown liquid, rich in solvent.
• the cake was filtered and analyzed, DS of cake was about 38%, hexanol content was about 60%, and HCI on as is basis was about 0.7%.

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