WO2009062601A2

WO2009062601A2 - Method for the fermentative production of butanol from a mash from which non-fermentable substances and solids were separated prior to fermentation

Info

Publication number: WO2009062601A2
Application number: PCT/EP2008/009162
Authority: WO
Inventors: Martin Ehrig; Werner BÄCKER; Jürgen BAUSA; Andre Düx; Sebastian Schmidt; Michael Traving; Mitja Medved; Günter OLF; Georg Ronge; Rafael Warsitz
Original assignee: Bayer Technology Services Gmbh
Priority date: 2007-11-12
Filing date: 2008-10-30
Publication date: 2009-05-22
Also published as: CL2008003199A1; WO2009062601A3; AR069259A1; DE102007054150A1

Abstract

The invention relates to a method for producing biobutanol by way of fermentation of plant raw materials and reverse osmosis as the separation step.

Description

Process for the production of biobutanol from biomass

The invention relates to a process for the production of biobutanol by fermentation from vegetable raw materials using reverse osmosis as separation step.

Biobutanol can be obtained by fermentation from solutions containing sugar and starch, reviewed in D. Jones and D. Woods in their article "Acetone butanol revisited" (Microbiological Reviews, 1986, p.484-524) for the processes described In addition, the process is characterized in that the dissolved glucose is converted to butanol in discontinuously operated fermenters, acetone, ethanol, hydrogen and carbon dioxide being produced as byproducts According to Jones and Wood, fermentation mashes are limited to about 12-22 g / l, which corresponds approximately to proportions in the fermentation mash of 1.2 to 2.2% by weight, so that the direct product separation from the resulting suspension is quite complicated and influences the Economic efficiency of the process negative.

The use of reverse osmosis for the partial separation of the produced butanol from 0.6% by weight to 1-2% by weight is disclosed by Yiamsobat, S. et al. (Microbial Utilization of Renewable Resources (1991) 7, 544-550), however previously separated the biomass from the fermentation mash by means of microfiltration and used a pure glucose solution as starting material for the conversion to butanol. Due to this, the technical feasibility of such a method is not disclosed, since the glucose solution used can be considered economically unsuitable as a starting material due to their high cost. The resulting problem of contamination when using fiber and protein-containing vegetable raw materials as a starting material is thus also not considered and thus no approaches to their solution disclosed. The increase in the butanol content of the process by only a factor of about 3 to 1 -2% by weight further renders the disclosed process unfavorable since subsequent treatment steps would require a comparable energy expense requiring direct product separation from the resulting product Perform mixture.

Albert Garcia III. also discloses concentrating a butanol-containing ultrafiltration permeate by reverse osmosis (Dissertation, University of Missouri-Columbia, USA, 1984; Biotechnology and Bioengineering, (1986) 28, 785-791). The starting material for fermentation is filtered corn mash. Furthermore, ultrafiltration after fermentation is provided to effect cell retention. Farther According to the disclosure, the feed for the reverse osmosis should be cleaned to the extent that no fouling occurs in this process step. The effect on the process step of reverse osmosis has been achieved, however, a rapid occupancy of the ultrafiltration membrane is also disclosed. Thus, there is no process step which previously separates those soluble components of the starting material which cause the coating to allow an economical and reliable operation of the process.

It thus sets itself the task of providing a process for the production of biobutanol by means of fermentation from solids-containing, vegetable raw materials, which solves the problems of the prior art and which results in a reduced energy consumption of the overall process.

It has surprisingly been found that the object is achieved by means of a process for the production of biobutanol from vegetable raw materials comprising at least the steps:

a) converting the vegetable raw materials into a high-glucose fraction comprising usable sugars,

b) at least partially converting the usable sugars contained in the glucose-rich fraction into biobutanol by means of microorganisms by a fermentation,

c) separating the microorganisms containing a fermentation product comprising biobutanol and a biomass solution comprising the microorganisms, and optionally at least partially recycling the biomass solution into the fermentation and / or blending the ground vegetable raw materials according to step ab)),

d) separating at least a portion of the biobutanol contained in the fermentation product by a reverse osmosis, and optionally at least partially recycling the remaining fermentation product obtained from step d) into the transformation by a fermentation,

e) optionally further treating the obtained from step d) by reverse osmosis

Biobutanollösung,

characterized in that converting the vegetable raw materials into a high-glucose fraction containing usable sugars according to a) at least the steps

aa) grinding the vegetable raw materials, ab) blending the ground vegetable raw materials from aa) with water, obtaining a mash,

ac) optionally separating dissolved and / or dispersed, non-fermentable substances from the mash and drying the dissolved and / or dispersed, non-fermentable substances,

ad) treating the mash in the aqueous with at least one enzyme for the cleavage of poly-sugars,

ae) separating the solids fraction remaining after ad), containing the high-glucose fraction containing usable sugars

includes, can be solved.

The process according to the invention can be carried out continuously or batchwise. Preference is given to a batchwise procedure.

For all the steps according to the invention and the preferred embodiments described below, they can be repeated several times individually or in groups a) to e) and aa) to ae).

As the biobutanol, in the present invention, all isomers of an alcohol having four carbon atoms and mixtures and solutions containing at least one of these isomers and produced by a process containing at least one process step in which a biological reaction is carried out are referred to. Preference is given to 1-butanol and / or isobutanol and / or their aqueous solutions. Particularly preferred are aqueous solutions of 1-butanol.

Plant raw materials are, in the context of the present invention, all plants and / or substances obtained from these plants or mixtures thereof, which contain poly-sugars for the purposes of the present invention. Preferred as vegetable raw materials are cereals. Particularly preferred are rye, wheat, barley and corn.

Poly-sugars in the present invention designate all substances of the empirical formula (C _n (H ₂ O) _n ) _m , where m denotes the number of units of the sugar C _n (H ₂ O) _n in the poly-sugar and a value> 1 has and n can be any number from 3 to 6. The poly-sugars are preferred Hexoses or Pentoses (5 ≤ n <6) Particularly preferred are the poly-sugars, xylans, dextrins and cellulose

Microorganisms according to the invention include species from the domain of the bacteria and / or the domain of the eukaryotes and the kingdom of fungi. Species of the genus Clostπdien are preferred. The species Clostridium acetobutyhcum, Clostridium beijeπnckn, Clostridium saccharobutyhcum or Clostridium saccharoperbutylacetonicum and / or mixed cultures thereof are particularly preferred

The preferred microorganisms are listed under the following numbered species in the German Collection of Microorganisms and Cell Cultures (DSMZ), and optionally the American Type Culture Collection (ATCC). The preferred strains of the species Clostridium acetobutyhcum are available under the numbers DSM792 ( ATCC824), DSM1731 (ATCC4259), DSM1732, DSM1733, DSM1737 (ATCC3625), DSM1738 (ATCC8529), DSM4685 and DSM6228 (ATCC39236) deposited in the DSMZ The preferred strains of the species Clostridium beijeπnckii are under the numbers DSM51 (ATCC 7797), DSM53 (ATCC14949), DSM552, DSM791 (ATCC25752), DSM1739 (ATCC10132), DSM 1820 (ATCC858), DSM6422, DSM6423 and DSM 13821 deposited in the DSMZ The preferred strains of the species Clostridium saccharobutyhcum are under the number DSMl 3864 (ATCC BAA-1 17) deposited in the DSMZ The preferred strains of the species Clostridium saccharoperbutylacetonicum under the number DSM2152 (ATCC27022) and DSM 14923 (ATCC27021) deposited in the DSMZ The respective strains are described in terms of their properties and recovery in the literature and are summarized in Keis et al (International Journal of Systematic and Evolutionary Microbiology (2001), 51, 2095-2103)

Usable sugars are poly-sugars according to the invention for which the microorganisms which can be used according to the invention have a metabolism for their utilization. Poly-sugars of the hexoses and / or pentoses with m <3 are preferred

When converting the vegetable raw materials into a glucose-rich fraction containing usable sugars according to step a) of the process according to the invention, the milling of the vegetable raw materials according to step aa) of the inventive method is preferably carried out by fractional milling, the detailed execution of which is known in the art a fractional grinding the interconnection of a mill known to the expert with a Klassiervorπchtung known in the art are very particularly preferred as mills known to those skilled in the buzzword mill types of Walzenstuhle, Hammer Mills and Impact Mills Also very particularly preferred are the Klassiervorπchtungen known to those skilled in the buzzwords in their details Klassierertypen the drum screens, Plansichter and throw sieves

A fractional grinding is advantageous, because in step aa) of the process according to the invention non-fermentable vegetable raw materials can be separated. These non-fermentable vegetable raw materials may comprise, depending on the enzymes used in step ad) of the process according to the invention, for example proteins, cellulose or lignocellulosic raw material constituents

The Veπnengen the ground vegetable raw materials from step aa) with water according to step ab) of the inventive method is preferably such that a mixture with 10 to 50% by weight ground vegetable raw material in water results particularly preferred is a resulting mixture with 20 to 40 wt -% ground plant raw material in water is further preferred blending elevated under compared to room temperature (20 ⁰ C) temperature more preferably, the temperature amounts to at blending between 30 ⁰ C and 70 ⁰ C. most preferably, the temperature amounts to at blending about 55 ° C also the mixing of the ground vegetable raw materials from aa) with water according to (a) of the process according to the invention is preferred at a pH of less than 7. Mixing at a pH of from 5 to 6 is particularly preferred

The preferred proportions of ground vegetable raw material in water are particularly advantageous because the resulting mash is concentrated high enough to achieve economical space-time yields in the process, but is not yet so concentrated that its further treatment by the increased viscosity and Sedimentation is process technically too complex and thus uneconomical

The increase of the temperature to the very particularly preferred about 55 ° C is particularly advantageous because this difficult soluble poly-sugar fractions of the mash are better dissolved in the water and thus for the enzymatic treatment according to step ad) of the inventive

Be available method, whereby a larger amount of high-glucose Fiaktion can be obtained, which in turn in the following fermentation causes an increased space-time yield A further increase in temperature is energetically complex and thus leads to an increasingly uneconomical operation of the overall process

The particularly preferred reduction of the pH to 5 to 6 is particularly advantageous because it allows parts of the poly-sugars to be split by means of acidic hydrolysis the pH optimum of the at least one enzyme used in the slightly acidic to acidic, so that hereby a presetting of the pH value for the following process steps can be achieved This and the partial cleavage of poly-sugar lead to a further increase in the space-time yield of the overall process and are thus economically particularly advantageous

The process according to the invention can be carried out with or without separation of dissolved and / or dispersed non-fermentable substances from the mash and drying of the dissolved and / or dispersed non-fermentable substances according to step a). Preferably, the separation of dissolved and / or or dispersed, non-fermentable substances from the mash and drying of the dissolved and / or dispersed, non-fermentable substances Preferably separated, dissolved and / or dispersed, non-fermentable substances include gluten and / or lignin and / or cellulose. Particular preference is given to the separation of gluten

In the context of this invention, non-fermentable substances are substances which can not be converted into biobutanol by the microorganisms according to the invention in any further process step or in a combination of other process processes. For example, cellulose is a non-fermentable substance for the purposes of the present invention if it is not converted into usable sugars in step ad) by means of an enzyme (eg cellulase)

The separation according to step ac) is usually carried out using separators and / or hydrocyclones in their customary, known to those skilled embodiments Preferably, an interconnection of at least one hydrocyclone and / or at least one separator in their usual, known to the skilled person embodiments Particularly preferred conventional Embodiments for separators are Dusenseparatoren, press screw separators, chamber separators, Tellerseparatoren and / or Vollmanteltellerseparatoren

The drying according to step ac) is particularly preferably carried out by thermal and / or pressure treatment of the separated gluten. Very particular preference is given to a thermal treatment at elevated temperatures (20 ^° C.) together with a pressure treatment at pressures below ambient pressure (1013 hPa).

If a separation according to step ac) of the method according to the invention takes place, then the sequence of steps ac) and ad) is selectable. However, step ad) is preferably carried out after step ac) The implementation of step ac) of the inventive method is particularly advantageous because achieved by the prior separation of z B also dissolved non-fermentable substances and the unresolved from the prior art remaining object of reducing or preventing the formation of deposits on membranes or surfaces subsequent Verfahrensschπtte can be (Fouhng)

The treatment of mash in Wassπgen with at least one enzyme for cleavage of poly-sugars according to step ad) of the inventive method can be carried out in one or two steps Preferably, a procedure in two steps Here, in a first step of the mash at least one enzyme the class of amylases and / or cellulases and / or xylanases and / or glucosidases are added preferred amylases sold under the trade name Novozyme ^0O 50024 (Novozymes Germany GmbH) marketed enzyme and / or the (under the brand name Liquozyme °° SC DS Fa Novozymes Deutschland GmbH) sold enzyme is particularly preferred as amylase Novozyme ^w 50024 in a ratio of 20 to 80 .mu.l per kg of ground vegetable raw material in the mash and / or milled as another amylase Liquozyme SC DS in a ratio of 150 to 250 .mu.l per kg vegetable raw material used in the mash This first step is preferred at a temper ature of 90 ⁰ C to 95 ° C carried out, this first step is also preferred that this first step is particularly preferably at a pH of less than 7 carried out at a pH value of 5 to 6 by out The residence time of the mash in the first step amounts to preferably In a second step of the preferably two-step procedure according to step ad) of the process according to the invention, the mash resulting from the first step is again at least one enzyme of the class of amylases and / or cellulases / or xylanases and / or glucosidases are added. Preferred as amylases are the enzyme marketed under the brand name Novozyme®50024 and / or the enzyme marketed under the brand name Spiπzyme®Fuel. Amylase Novozyme® °° 50024 is preferred in a ratio of 400 to 600 μl per kg of ground vegetable raw material in the mash and / or as further e Amylase Spinzyme ^ uel (Fa Novozymes Germany GmbH) used in a ratio of 400 to 600 .mu.l per kg of ground vegetable raw material in the mash This second step is preferably carried out at a temperature of 50 ⁰ C to 70 ⁰ C Also preferred is this second Step at a pH value less than 6 is particularly preferably carried out this second step is carried out at a pH of 4 to 5. The residence time of the mash in the second step is preferably between 12 and 36 hours, more preferably between 24 and 32 hours If the treatment of mash in Wassπgen with at least one enzyme for cleavage of poly-sugars according to step ad) of the inventive method in one step, preferably the same enzyme classes or preferred enzymes from these classes of the two-stage process or mixtures thereof are used The procedure for cleaving poly-sugars according to step ad) of the process according to the invention is preferably carried out using the same preferred proportions of ground vegetable raw materials in water as in a two-stage procedure. For carrying out the single-stage process, pH values less than 7 are preferred. The temperature of the one-stage process for cleavage of poly-sugars according to step ad) of the inventive method amounts to between 50 ⁰ C and 70 ⁰ C The preferred residence time of the mash in a one-step process is preferably between 24 and 32 hours

The procedure described in two steps for the cleavage of poly-sugars according to step ad) of the inventive method is particularly advantageous because the pre-treatment prevents the not yet completely split poly-sugar, which simplifies the process engineering treatment of the mash for both Processes (one or two steps) for the cleavage of poly-sugars according to step ad) of the inventive method given temperatures and pH values are particularly advantageous because they include the pH values and temperatures in which the enzymes used are particularly effective, so that a maximum space-time yield can be achieved

The separation of the solids fraction remaining after ad) in step ae) of the process according to the invention can be carried out with or without the use of a flocculant. Possible separation processes include filtration, sedimentation, classification, decantation or centrifugation. Combinations and / or repetitions of the abovementioned separation processes with or without are also possible Use of a flocculant Preferably, separation with or without use of a flocculant using the separation process of decantation Suitable flocculants include cationic and / or anionic and / or nonionic polymers. Preferred are cationic polymers, most preferably the flocculant Praestol® 853 BC, Stockhausen GmbH & Co. KG

In a preferred embodiment of the present invention, after carrying out step ae) of the process according to the invention, the separated remaining solids fraction is fed to a biogas production This preferred embodiment is advantageous because the recovered biogas can be burned and the energy obtained from it can be used directly in the inventive process in the form of heat or electricity.

In a further preferred embodiment of the present invention, after carrying out step ae) of the method according to the invention, the separated remaining solids fraction is dried and further processed into animal feed.

This further preferred embodiment of the invention is advantageous because the sale of the animal feed the cost of the process can be increased.

The at least partially converting the usable in the glucose-rich fraction usable sugars in biobutanol by microorganisms by a fermentation according to step b) of the method according to the invention is preferably carried out in an anaerobic, operated at room temperature (20 ⁰ C) elevated temperature fermentation. The fermentation is particularly preferably operated anaerobically at an oxygen partial pressure of not more than 1 hPa at ambient pressure (1013 hPa) and a temperature of 30 ° C to 50 ⁰ C. Most preferably, the fermentation is operated anaerobically at an oxygen partial pressure of not more than 0.5 hPa at ambient pressure (1013 hPa) and a temperature of about 35 ° C. The residence time in the fermentation according to step b) of the process according to the invention is preferably between 24 and 72 hours, more preferably about 48 hours.

Also preferably, step b) of the process according to the invention is carried out so that in the fermenter, the proportion of the high-glucose fraction in the total mass of the reactor contents is between 10 and 30% by weight. Particularly preferably, the proportion is between 20 and 25% by weight. Further preferably, step b) of the process according to the invention is carried out at a pH of between 4 and 5, more preferably at about 4.5.

The preferred embodiments of step b) of the method according to the invention are particularly advantageous because the anaerobic operation of the fermenter, the microorganisms produce by means of a fermentation metabolism alcohols, especially butanol, in an increased amount. The preferred temperatures and pH values are particularly advantageous conditions for the microorganisms and consequently also lead to an increased amount of produced biobutanols.

The separation of the microorganisms according to step c) to obtain a fermentation product comprising biobutanol and a biomass solution comprising the microorganisms can be carried out with or without at least partial recycling of the biomass solution into the fermentation and / or into the fermentation Preferably, the separation takes place by one of the abovementioned separation processes preferred for step ae) of the process according to the invention and / or by an ultrafiltration

It is preferred to provide at least partial transfer of the biomass solution from step c) into the conversion by fermentation and / or mixing of the ground vegetable raw materials according to step ab) of the process according to the invention. This embodiment is advantageous because it keeps the microorganisms as producers Dead microorganisms can be used at least partially as a substrate of the living microorganisms. This results in a higher space-time yield of the overall process. Furthermore, the separation of the microorganisms poses the risk of leaving the process in step d) of the process according to the invention used at least reduced membrane

The separation of at least part of the biobutanol contained in the fermentation product by reverse osmosis according to step d) of the inventive method can be carried out with or without at least partial zurückuck the obtained from step d) residual fermentation product in the conversion by a fermentation is preferably an at least partial return of the Step d) obtained residual fermentation product in the

Fermentation transformation This is advantageous because so utilizable sugars, which have not yet been converted to biobutanol by the microorganisms, continue to be converted to biobutanol

Conversion to biobutanol are available

Also preferred is the separation of at least a portion of the biobutanol contained in the fermentation product by reverse osmosis using membranes. Suitable membranes include film membranes Preferred film membranes include cellulose or cellulose membranes, polyamides, polysulfones and / or polysiloxanes. Preferred film membranes are film membranes sold by the company Lenntech under the name FiInUeC ⁰⁰ BWGO

Cellulose derivatives in this context denote chemical compounds in which further chemical groups are covalently bound to the basic cellulose skeleton. Carboxymethylcellulose is to be regarded as such (a part of the hydroxyl groups of the cellulose is as ether with a - CH ₂ - COOH (carboxymethyl)) group linked) and hydroxypropylmethylcellulose (a part of the hydroxyl groups of the cellulose is linked as ether with a - CH ₃ group, another than ether with - CH ₂ - CHOH - CH ₃ ) Reverse osmosis is usually operated in such a way that a predetermined proportion of biobutanol is obtained in the retentate. Corresponding techniques are known to the person skilled in the art of the pressure gradient applied across the membrane by means of a pump on the retentate side, which generates a suitable overpressure and thus causes the passage of the permeate through the membrane, or the setting of suitable residence tents z B of the fermentation product in the reverse osmosis z B under suitable pressures mentioned above until the z B are achieved by conductivity or optical methods, such as refractive index, or optical density at a certain wavelength certain proportions z B of biobutanol

In a preferred embodiment of the separation by reverse osmosis according to step d) of the inventive method, the reverse osmosis is operated at a pressure of at least 30 bar, more preferably of at least 40 bar, most preferably of at least 50 bai

In a likewise preferred embodiment of the separation by reverse osmosis in accordance with step d) of the process according to the invention, the reverse osmosis is carried out until the retentate contains between 3 and 30% by weight, more preferably between 5 and 10% by weight, of biobutanol

If further treatment of the biobutanol solution obtained from step d) by reverse osmosis is provided according to step e) of the process according to the invention, this z B comprises the further concentration of the biobutanol by extraction and / or distillation and / or rectification according to customary methods known to the person skilled in the art Forming of these Processes Further concentration of the biobutanol is preferred by distillation and / or rectification according to customary embodiments of these processes known to the person skilled in the art, wherein in a particularly preferred variant of the process the bottoms product of the distillation and / or rectification predominantly consists of water , in the fermentation according to step b) or the blending of the ground vegetable raw materials from step aa) with water according to step ab) of the inventive method is recycled

The execution of the further treatment according to the distillation and / or rectification of the preferred embodiment of step e) of the inventive method is particularly advantageous because by this further treatment and the resulting bottom product of the distillation and / or rectification of the energy expenditure of the entire invention Process is reduced per unit of obtained biobutanol, in that parts of the process streams in the process can be demanded in a circle and thus the energy content of these process streams is not removed from the process

The invention and preferred embodiments will be explained in more detail by way of example with reference to the figures without, however, limiting them to them

Fig. 1

Grain is first subjected to a fractional grinding z B using a hammer and a drum screen, the bran being separated. Subsequently, in one step (mashing), the product of the fractional grinding is mixed with water (eg recycled water, rec The subsequent treatment with enzymes is carried out here in two steps, wherein in the first (liquefying) and second (saccharification) step in addition to the enzymes used Auxiliary substances, for example in the form of co-enzymes, are added. The product of the enzymatic treatment is then largely freed from solid with the prior addition of flocculants (solid-liquid separation), the solid fraction being dried and used as animal feed

The liquid fraction of the solid-liquid separation, comprising the usable sugar is therefore together with further water (eg Rec-water), which may also come from the reverse osmosis, but also from the distillation, the conversion (fermentation) fed in the Fermentation contains microorganisms to convert the usable sugars, for example, into biobutanol, CO ₂ and hydrogen. In this particular case, further nutrient media and auxiliaries are added to the fermentation. Nutrient media and auxiliaries may here include yeast extract, salt solutions or the like

The entire product of the fermentation is a Bakteπenabtrennung, eg fed in the form of an ultrafiltration and the stream containing the larger proportion of microorganisms is the

Fermentation fed back The other part of the stream of bacteria separation is subsequently subjected to a reverse osmosis to concentrate the biobutanol whose Biobutanol- fraction is fed to a subsequent distillation and their remaining fraction as

Recycling water (Rec-water) z B reused in the process network or discarded as waste water In the subsequent distillation, the biobutanol is further concentrated, in which case the separated Rec water can be reused in the process network In the particular case of the embodiment of the invention shown, the distillation is followed by a further step (product preparation) in which by-products which could not be separated from the biobutanol by means of the previous separation processes are separated. Such by-products include, for example, other alcohols, such as ethanol and Methanol, or acetone and other ketones, or aldehydes of the alcohols produced in the process, and possibly also the acids of the alcohols. This results in a further purified biobutanol (product) and a mixture of by-products

Fig. 2

In contrast to the embodiment of the process according to the invention shown in FIG. 1, a further step is interposed between mashing and enzymatic conversion (liquefaction, saccharification) (gluten separation). The gluten separation leads to an already prepared product stream which is passed into the enzymatic conversion. so that after these two steps, no addition of flocculants for solid-liquid separation is necessary The separated gluten is dried and thus represents another by-product of the inventive method, which increases the efficiency of the entire process z B for use in the Lifter technology for pasta can be sold

In contrast to Figure 1, the solid fraction obtained from the solid-liquid separation is not supplied here for further utilization in the form of animal feed, but used for the production of biogas The biogas can, for example, by fermenting the solids fraction with similar microorganisms, such as those in the Fermentation, but also done by means of other microorganisms or chemical-physical processes The resulting biogas can be used in the sequence either in the form of a direct combustion to produce heat, which z is returned to the novel process in the distillation or fermentation, or the resulting biogas is burned and used to generate electricity, eg by evaporating water and passing it into a steam turbine. The power generated can either be made available again to the process according to the invention in which, for example, the reverse osmosis pump is operated here in the sense of Steiger the economy of the whole process will be sold 4:

In this particular embodiment of the method according to the present invention, the particular process features of Fig. 2, with the possibility of generating biogas as shown in Fig. 3 are combined.

The invention and preferred embodiments are explained in more detail below with reference to the examples without, however, limiting them to these.

Examples

Example 1: Butanol fermentation with cereals in general (non-fermentable by-products to feed)

In the fractional milling of 100 kg of rye about 20 kg of bran were separated, so that, minus the loss of water resulted in about 79 kg of flour. For mashing, about 144 kg of water, which already contained the enzymes required for liquefaction, were added to this rye flour CNovozymes ⁽ * 50024: 50 μl / kg of flour, Liquozyme ™ SC DS: 200 μl / kg of flour) and the mixture was brought to a temperature brought from 55 ° C. By adding a 2 mol% sulfuric acid solution, a pH of 5.5 was set.

Subsequently, the liquefaction was carried out at 92 ° C and a residence time of 2 h. After cooling to 63 ° C, the saccharification took place with a residence time of 28 h. The saccharification ^{enzymes used} were Novozyme ^Qδ 50024 (500 μl / kg flour) and SpirizymeΥuel (500 μl / kg flour). The pH during the saccharification was 4.2 and was adjusted by the addition of 10 mol% phosphoric acid.

After saccharification the mash a quantity of 200 g of Praestol ^<lή 853 BC (Fa. Stockhausen GmbH & Co KG) was added as coagulant or flocculant to convert the dissolved proteins and gluten in a solid. Thus, these could be separated in a decanter together with the other insoluble solids constituents of the sweet mash. This resulted in about 96 kg of solid concentrate, which corresponds to 43% based on the flow of fresh mash. This fraction was fed to drying together with the bran.

To the solids-free high-glucose fraction of about 126 kg 400 kg of water were added for further dilution and fed this solution to a fermentation. Thereafter, about 20 kg of active cell cultures of Clostridium acetobutylicum were also added to the fermenter. Subsequently, a pH of 4.3 was adjusted by the addition of 10 mol% phosphoric acid. The fermentation was operated at 36 ° C and a residence time of 48 h. Thereafter, the butanol concentration in the solution was about 16 g / l. Subsequently, the bacterial cultures were separated by ultrafiltration, so that they could be used again and the permeate of the ultrafiltration of the reverse osmosis could be supplied.

The permeate resulting from the ultrafiltration was treated batchwise by means of reverse osmosis. For this purpose, a flat membrane from Lenntech of the type Filmtec °° BW30 with a membrane area of 0.0045 m ^{2 was} used. The reverse osmosis was operated at a

Pressure of 50 bar (measured on the retentate side) and a temperature of 20 ⁰ C. Each batch The reverse osmosis was subjected to the above process conditions until a concentration of biobutanol of 60 g / L could be detected in the retentate.

From this retentate, the butanol was finally separated by distillation.

Claims

claims

A process for the production of biobutanol from vegetable raw materials comprising at least the steps

c) separating the microorganisms containing a fermentation product comprising biobutanol and a Biomasselosung comprising the microorganisms, and optionally at least partial repatriation of Biomasselosung in the fermentation and / or in the blending of the ground vegetable raw materials according to step from),

d) separating at least a portion of the biobutanol contained in the fermentation product by a reverse osmosis, and optionally at least partially returning the remaining fermentation product obtained from step d) into the transformation by a fermentation,

e) optionally further treating the biobutanol solution obtained from step d) by reverse osmosis,

aa) grinding the vegetable raw materials,

ab) blending the ground vegetable raw materials from aa) with water, obtaining a mash,

ac) optionally separating dissolved and / or dispersed, non-fermentable substances from the mash and drying the dissolved and / or dispersed, non-fermentable substances, ad) treating the mash in water with at least one enzyme for cleaving poly-sugars,

includes

2. Method according to claim 1, characterized in that the microorganisms comprise species of the genus Clostπdien

A method according to any one of the preceding claims, wherein the milling of the vegetable raw materials according to step aa) is a fractional milling

4 Vei drive according to one of the preceding claims, characterized in that the

Mash comprises 10 to 50% by weight, preferably 20 to 40% by weight, of ground vegetable raw material in water

5. The method according to any one of the preceding claims, characterized in that a separation of dissolved and / or dispersed, non-fermentable substances from the mash and drying of the dissolved and / or dispersed, non-fermentable substances according to step ac) is performed

6. The method according to any one of the preceding claims, characterized in that the treatment of mash in Wassπgen with at least one enzyme for the cleavage of poly-sugars according to step ad) takes place in two steps

A method according to claim 6, characterized in that the first step in a

Temperature of 9O ⁰ C to 95 ⁰ C and the second step at a temperature 50 ⁰ C to 70 ⁰ C are performed

8. The method according to any one of the preceding claims, characterized in that at least one enzyme for the cleavage of poly-sugars from the class of amylases or xylanases or glucosidases or cellulases

9. The method according to any one of the preceding claims, characterized in that the separation according to step ae) of ad) residual solids fraction takes place using a flocculant

10. The method according to any one of the preceding claims, characterized in that the conversion by a fermentation according to step b) anaerobically operated at room temperature (20 ⁰ C) elevated temperature.

1 1. A method according to any one of the preceding claims, characterized in that the separation of the microorganisms according to step c) is done by ultrafiltration.

12. The method according to any one of the preceding claims, characterized in that an at least partial recycling of the biomass solution from step c) in the conversion by a fermentation and / or in the blending of the ground vegetable raw materials according to step ab) of the method according to the invention.

13. The method according to any one of the preceding claims, characterized in that an at least partial recycling of the remaining fermentation product obtained from step d) is carried out in the conversion by a fermentation

14. The method according to any one of the preceding claims, characterized in that the further treatment of the biobutanol solution obtained from d) by reverse osmosis by distillation and / or rectification.

15. The method according to claim 1 1, characterized in that the bottom product of the distillation and / or rectification in the conversion by a fermentation and / or the blending of the ground vegetable raw materials is recycled.

16. The method according to any one of the preceding claims, characterized in that the separated remaining solids fraction is used for biogas production.

17. The method according to any one of the preceding claims, characterized in that the separated remaining solids fraction is dried and used as animal feed.