The subject disclosure relates to treatment of biomass in the production of ethanol. The subject disclosure also relates to treatment of pre-treated biomass before the pre-treated biomass is supplied to a fermentation system in order to facilitate the efficient production of ethanol.
Ethanol can be produced from grain-based feedstocks (e.g. corn, sorghum/milo, barley, wheat, soybeans, etc.), from sugar (e.g. from sugar cane, sugar beets, etc.), and from biomass (e.g. from cellulosic feedstocks such as switchgrass, corn cobs and stover, wood or other plant material).
Biomass comprises plant matter that can be suitable for direct use as a fuel/energy source or as a feedstock for processing into another bioproduct (e.g., a biofuel such as cellulosic ethanol) produced at a biorefinery (such as an ethanol plant). Biomass may comprise, for example, corn cobs and stover (e.g., stalks and leaves) made available during or after harvesting of the corn kernels, fiber from the corn kernel, switchgrass, farm or agricultural residue, wood chips or other wood waste, and other plant matter. In order to be used or processed, biomass will be harvested and collected from the field and transported to the location where it is to be used or processed.
In a biorefinery configured to produce ethanol from biomass, such as cellulosic feedstocks as indicated above, ethanol is produced from lignocellulosic material (e.g. cellulose and/or hemi-cellulose). The biomass is prepared so that sugars in the cellulosic material (such as glucose from the cellulose and xylose from the hemi-cellulose) can be accessed and fermented into a fermentation product that comprises ethanol (among other things). The fermentation product is then sent to the distillation system, where the ethanol is recovered by distillation and dehydration. Other bioproducts such as lignin and organic acids may also be recovered as co-products. Determination of how to more efficiently prepare and treat the biomass for production into ethanol will depend upon (among other things) the form and type or composition of the biomass.
One of the costly steps in the preparation of lignocellulosic material for fermentation is the hydrolysis of the cellulosic material, which requires the usage of enzymes in order to degrade the cellulose to sugars. Typically, large doses of enzymes are required for hydrolysis since it is believed that lignin may bind to some of the enzymes rendering them inactive. As enzymes are a significant portion of the overall cost of hydrolysis, there is an inefficiency in conventional techniques that has not been addressed.
An aspect relates to a method for treating lignocellulosic biomass to be supplied to a fermentation system for production of a fermentation product. The method comprises pre-treating the biomass into pre-treated biomass and separating the pre-treated biomass into a liquid component comprising sugars and a solids component comprising cellulose and lignin. The method also comprises treating the solids component of the pre-treated biomass into a treated component. The biomass comprises lignocellulosic material. Treating the solids component comprises application of an enzyme formulation and an agent to form a slurry. The enzyme formulation comprises a cellulase enzyme. The agent may include clarified thin stillage or effluent from an anaerobic membrane digester, in some embodiments.
According to an embodiment, treating the solids component releases sugar. According to another embodiment, pre-treating the biomass comprises steeping, wherein the steeping comprises mixing the biomass and applying sulfuric acid to the biomass.
In order that the disclosed aspects may be more clearly ascertained, some embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
The various aspects will now be described in detail with reference to several embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the one or more aspects. It will be apparent, however, to one skilled in the art, that embodiments may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the various aspects. The features and advantages of embodiments may be better understood with reference to the drawings and discussions that follow.
Aspects relate to systems and methods for enzyme hydrolysis of the solid portion of lignocellulosic hydrolysate using the addition of an agent in order to reduce enzyme load requirements and increase efficiency. Various aspects disclosed herein provide for treating biomass in the production of ethanol. Aspects also provide for improving efficiencies of the hydrolysis of cellulose. The systems and methods of the aspects disclosed herein provide cost effective means for increasing the efficiency of the conversion of cellulosic materials into fermentable sugars.
Referring to
As shown in
Referring to
Referring to
In accordance with the embodiments of
In the alternate embodiment of
During treatment of the C5 and/or C6 stream, components may be processed to recover byproducts, such as organic acids and lignin. The removed components during treatment and production of ethanol from the biomass from either or both the C5 stream and the C6 stream (or at distillation) can be treated or processed into bioproducts or into fuel (such as lignin for a solid fuel boiler or methane produced by treatment of residual/removed matter such as acids and lignin in an anaerobic digester) or recovered for use or reuse.
According to an embodiment, the biomass comprises plant material from the corn plant, such as corn cobs, corn plant husks and corn plant leaves and corn stalks (e.g. at least the upper half or three-quarters portion of the stalk). According to some aspects, the composition of the plant material (e.g. cellulose, hemicellulose and lignin) will be approximately as indicated in
According to an embodiment, pre-treatment of biomass can be performed as described in U.S. patent Ser. No. 12/716,984 entitled “SYSTEM FOR PRE-TREATMENT OF BIOMASS FOR THE PRODUCTION OF ETHANOL”, which is incorporated by reference in its entirety.
According to an embodiment, in the pre-treatment system an acid can be applied to the prepared biomass to facilitate the breakdown of the biomass for separation into the liquid (pentose liquor) component (C5 stream from which fermentable C5 sugars can be recovered) and the solids component (C6 stream from which fermentable C6 sugars can be accessed). According to some embodiments, the acid can be applied to the biomass in a reaction vessel under determined operating conditions (e.g. acid concentration, pH, temperature, time, pressure, solids loading, flow rate, supply of process water or steam, etc.) and the biomass can be agitated/mixed in the reaction vessel to facilitate the breakdown of the biomass. According to exemplary embodiments, an acid such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, etc. (or a formulation/mixture of acids) can be applied to the biomass. According to a particular embodiment, sulfuric acid can be applied to the biomass in pre-treatment. According to a particular embodiment, the prepared biomass may be pretreated with approximately 0.8 to 1.5 percent acid (such as sulfuric acid) and about 12 to 25 percent biomass solids at a temperature of approximately 100 to 180 degrees Celsius for approximately 5 to 180 minutes. The pre-treatment may also comprise a steam explosion step, where biomass is heated to and held at (e.g. hold time) approximately 150 to 165 degrees Celsius under pressure (e.g. 100 psi) at a pH of about 1.4 to 1.6 for one to 15 minutes, and the pressure is released to further aid in the breakdown of cellulose. After pretreatment the pre-treated biomass is separated into a solids component (C6) and a liquid pentose liquor component (C5), as shown in
The liquid pentose liquor component (C5 stream) comprises water, dissolved sugars (such as xylose, arabinose and glucose) to be made available for fermentation into ethanol, acids and other soluble components recovered from the hemicellulose. (
The solids component (C6 stream) comprises water, acids, and solids such as cellulose from which sugar, such as glucose, can be made available for fermentation into ethanol, and lignin. (
Referring to
In some embodiments, the C6 solids may be subjected to a sequential hydrolysis and fermentation (SHF) process, wherein the solids are subjected to an enzyme hydrolysis (with a glucan conversion of at least 80%) followed by a fermentation. While requiring a two-step process, with the SHF approach enzyme hydrolysis may be performed at optimal pH and temperature for conversion of cellulose to sugars. Typically, for SHF, the solids are treated at about 50 degrees Celsius, pH 5.5 and 15% total solids slurry with cellulase.
Alternatively, the C6 solids may be subjected to a simultaneous saccharification and fermentation (SSF) process wherein the enzyme hydrolysis and fermentation is performed at about the same time. Simultaneous saccharification and fermentation can be performed at temperatures suitable for ethanol production by the yeast (e.g., about 37° C.) which may be less than optimal for the cellulase enzyme. As such, enzyme efficiency may be reduced. For both SSF and SHF binding of the cellulase enzymes to lignin may be a particular concern as, dependent upon the feedstock used, lignin can be dispersed on to the solids after dilute acid pretreatment, as discussed above. This may be particularly problematic when corn stover biomass is utilized as a feedstock.
According to an exemplary embodiment, an enzyme formulation comprising an enzyme capable of hydrolysing cellulose is supplied to the solids component (C6) to facilitate the enzyme hydrolysis, e.g. the saccharification by enzyme action of the polymeric cellulose (e.g. polymeric glucan) into accessible monomeric sugars (e.g. monomeric glucose). An example of such cellulase enzyme is Cellic CTec (e.g. NS22074) from Novozymes North America, Inc. of Franklinton, N.C. The amount or loading (dose) of enzyme formulation may be varied as an operating condition. According to an exemplary embodiment, approximately 2 to 12 milligrams of enzyme protein per gram of cellulose may be added. According to a particular embodiment, approximately 3 to 9 milligrams of enzyme protein per gram of cellulose may be added. In accordance with some aspects, the addition of agents to boost enzyme efficiencies is utilized for the enzymatic hydrolysis of cellulose containing materials. Given that enzymes are responsible for a large portion of the cost associated with the hydrolysis of cellulose materials, reducing the enzyme loading required, or gaining cellulose conversion efficiency, may be beneficial in the marketplace.
As such, embodiments disclosed herein are directed toward the addition of agents to the reaction vessel 502 in order to improve the efficiency and yield of enzymatic hydrolysis of pre-treated cellulose. The pretreated solids include lignin and other materials which may bind proteins. When enzymes are added to the reaction vessel 502 some portion of these enzymes become bound by the lignin and/or other particulates. This may render the bound enzymes less efficient, or even inactive. As such, enzyme efficiency of the entire hydrolysis decreases. In order to overcome this reduction in efficiency, traditionally a greater level of enzymes were added.
When the addition of another protein source is provided, by way of an agent, these proteins may compete for binding sites on the lignin material. This results in less binding of the enzymes and a correlated increase in hydrolysis efficiency. Possible sources of protein-rich byproducts in an ethanol plant include thin stillage, Anaerobic Membrane Bioreactor (AnMBR) effluent, wet cake, whole stillage and other byproducts. Particular examples of agent additives for the improvement of hydrolysis efficiency will be discussed in greater detail below.
According to a first embodiment, the agent may comprise a thin stillage composition from a conventional (e.g. corn based) ethanol production facility. According to a particular embodiment, the agent may comprise clarified thin stillage from a conventional (e.g. corn based) ethanol production facility. Clarified thin stillage can be produced from thin stillage by removal of substantially all of solids and oil contained in the thin stillage. Clarified thin stillage comprises essentially water and soluble components of thin stillage. According to an embodiment, the agent comprises as an active component at least a part of the soluble components comprised in thin stillage.
According to a second embodiment, the agent may comprise an effluent composition from the anaerobic membrane bioreactor of a cellulosic (e.g. biomass based) ethanol production facility. The lignin cake that results after distillation in the biomass based ethanol plant is digested in an anaerobic membrane bioreactor type. Digestion of the wet cake materials by anaerobic microorganisms substantially maintains nutrient value of the material. The membrane separates the relatively clean effluent from the solids and microorganisms. The effluent from the digester can have high levels of extracellular polymeric substances (EPS) that include protein, lipids, and nucleic acids.
The active protein components that are present in thin stillage and anaerobic membrane bioreactor effluent may also be present in other fermentation products or co-products and intermediates, such as beer, whole stillage, wet cake, syrup, backset and dried distillers grains (with or without solubles), any of which may be used as a constituent of the agent, according to an embodiment. According to an alternative embodiment, the agent may comprise corn germ steep liquor, which can be produced by steeping corn germ (produced for example in a fractionation system from corn kernels) in water or a water based liquid. Other agents (e.g. potassium hydroxide or sodium hydroxide for pH adjustment) may also be supplied to the treatment vessel.
The amount of thin stillage, clarified thin stillage, and/or anaerobic membrane bioreactor effluent applied to the treatment of the solids component (C6) may vary from about 1 to 90 percent of all the liquid present, according to an exemplary embodiment. According to an embodiment, the amount of thin stillage, clarified thin stillage, or anaerobic membrane bioreactor effluent may vary from about 20 to 70 percent of all the liquid present.
According to an exemplary embodiment, the temperature during the treatment of the solids component (C6) may be approximately 30 to 60 degrees Celsius. According to an embodiment, the temperature during the treatment of the solids component (C6) may be approximately 45 to 55 degrees Celsius. According to a particular embodiment, the temperature during the treatment of the solids component (C6) may be approximately 49 to 51 degrees Celsius.
According to an exemplary embodiment, the treatment time of the solids component (C6) may be approximately 48 to 144 hours. According to an embodiment, the treatment time of the solids component (C6) may be approximately 60 to 120 hours, and according to a particular embodiment, the treatment time of the solids component (C6) may be approximately 72 to 96 hours.
According to an exemplary embodiment, the solids content of the solids component (C6) supplied to the treatment system may be approximately 5 to 25 percent by weight. According to an embodiment, the solids content of the solids component (C6) may be approximately 10 to 20 percent by weight. According to a particular embodiment, the solids content of the solids component (C6) may be approximately 12 to 17 percent by weight.
According to an exemplary embodiment, the pH during the treatment of the solids component (C6) may be approximately 4.8 to 6.2. According to an embodiment, the pH during the treatment of the solids component (C6) may be approximately 5.2 to 5.8. According to a particular embodiment, the pH during the treatment of the solids component (C6) may be approximately 5.4 to 5.6.
As illustrated in the graph of
A series of limited examples were conducted according to an exemplary embodiment of the system in an effort to evaluate the effect of using various agents in the treatment of the solids component (C6). Experiments and tests were conducted to evaluate glucose yields for C6 hydrolysis with the addition of various agents. The following examples are intended to provide clarity to some embodiments of systems and means of operation and is not intended to limit the scope of the disclosed aspects.
The system used for the examples comprised a temperature-controlled reaction vessel and a pressure tube. Biomass comprising roughly 35 percent cob, 45 percent husks and leaves, and 20 percent stalks was pre-treated by steeping with approximately 1 to 1.3 percent acid (e.g. sulfuric acid) at 140 degrees Celsius with 14.3 percent solids for 50 minutes and by steam explosion at pH 1.5, at roughly 154 degrees Celsius and a hold time of 4 minutes. The pre-treated biomass slurry was supplied to the reaction vessels along with make-up water and enzymes to reach 12 to 15 percent solids and was studied for conversion of cellulose to glucose. Fermentation yields for the resulting hydrolysis product were also measured.
In the first example, the pre-treated biomass was supplied to two reaction vessels with make-up water. The make-up water in one vessel consisted of water, and the make-up water in another vessel comprised 40 percent water and 60 percent clarified thin stillage. The clarified thin stillage was generated by centrifuging thin stillage (7% solids) at 5000 rpm for 20 minutes. After centrifugation, three layers are present: a solid pellet, a liquid middle layer, and an oil emulsion top layer. The middle liquid layer contains 4% solids and is considered clarified thin stillage. This layer was removed and used for the following examples.
The pH of the slurry was adjusted to 5.5 with potassium hydroxide and about 7.2 milligrams of cellulase containing enzyme formulation (e.g. Cellic CTec2, available from Novozymes North America, Inc. of Franklinton, N.C.) per gram of cellulose was added to each vessel. Enzyme hydrolysis was conducted at 50 degrees Celsius. The amount of glucose in each vessel was measured at 0, 24, 48, 72, and 96 hours by high pressure liquid chromatography (HPLC).
It was observed that at 96 hours the glucose yield of the biomass with water only was approximately 52.6 percent of theoretical, and the glucose yield of the biomass with water and clarified thin stillage was approximately 76.1 percent. The use of clarified thin stillage in biomass enzyme hydrolysis resulted in approximately 45 percent yield increase. The results are shown in
In the second example, a dose response study for determining the optimum level of clarified thin stillage (CTS) use in saccharification was conducted at two enzyme dosages: 5.6 and 8.4 mg of cellulase containing enzyme formulation per gram glucan. Ctec2 enzyme was used. The clarified thin stillage was used at 0 (control), 10, 20, 30, 40, 50, and 60% of the water makeup in the 15% total solids slurry. The saccharification was run for 96 h at 50° C., initial pH of 5.5 followed by a 48 h to 72 h fermentation at 32° C., initial pH of 5.5. Results of the total glucose (% w/v) 902 is plotted against the concentration of the Clarified Thin Stillage (CTS) 904 used in the water makeup, as shown in the example plot of
The results again indicate that the use of clarified thin stillage significantly improved glucose yield in the saccharification process. Further, the results from this SHF study showed only slight differences in glucose production from CTS addition between 20 and 60% of the total water as observed for both the tested enzyme doses.
In the third example experiment, following the 96 h enzymatic hydrolysis, the reactors were cooled to 32 degrees Celsius and the pH adjusted back up to 5.5. Urea was added at 0.06 g/L (as a nitrogen source) and Lactoside247 was added at 5 ppm. Yeast was inoculated at 0.5 g (dry)/L. The fermentations were carried out for up to 72 hours. Measurements of residual glucose levels were collected after 24 hours.
The residual glucose after 24 hours of fermentation 1002 was then plotted against the percent of CTS in the makeup water, as shown in example
The ethanol produced in 24 h was over 70% of theoretical from glucan or over 80% of theoretical maximum from glucan at the 5.6 mg EP/g glucan and 8.4 mg EP/g glucan, respectively. These ethanol yields were obtained when CTS was used at 20-60% of the water in the makeup. With no CTS added during saccharification, the final ethanol produced after 72 h of fermentation was 56% and 60% of the theoretical maximum from glucan at the two enzyme dosages tested, respectively. Thus, it appears that the addition of the lignin binding agent not only increases enzyme conversion of cellulose to glucose, but also increases fermentation efficiency.
In the fourth example experiment, a study was conducted to identify the optimum dose for the AnMBR effluent in enzymatic hydrolysis. For this example experiment, 5.8 mg enzyme per gram of glucan dose was tested. Again, Ctec2 enzyme was used. The AnMBR effluent was used at 0 (Control), 15, 30, 45, and 60% of the water makeup in the 15% total solids slurry. The saccharification was run for 115 h at 50 degrees Celsius, initial pH of 5.5 followed by 47 h fermentation at 32 degrees Celsius, initial pH of 5.5.
The percent of theoretical yield of glucose 1102 after the 115 hours of saccharification dependent upon percent AnMBR effluent makeup 1104 for this experiment is illustrated at
One advantage of using AnMBR effluent as an efficiency-enhancing agent is that the use of the AnMBR effluent stream maintains the process water balance. While thin stillage is a viable option, as noted above, the use of AnMBR effluent does not require transfer of water from the corn grain ethanol plant to the cellulosic plant. In addition to simplifying the water balance, the use of AnMBR effluent over thin stillage, or most other agents, avoids the potential for cross contamination between the cellulose plant and the corn grain ethanol plant.
In the fifth example experiment, following the 115 h enzymatic hydrolysis, the reactors were cooled to 32 degrees Celsius and the pH adjusted back up to 5.5. Urea was added at 0.06 g/L (as a nitrogen source) and Lactoside247 was added at 5 ppm. Yeast was inoculated at 0.5 g (dry)/L. The fermentations were carried out for 47 hours. Measurements for residual glucose were collected from the samples at 24 and 47 hours.
The residual glucose 1202 after 24 and 47 hours of fermentation was then plotted against the percent of AnMBR effluent 1204 in the makeup water, as shown in example
In the sixth example experiment, an experiment was performed to determine whether the combination of Clarified Thin Stillage (CTS) with Anaerobic Membrane Bioreactor (AnMBR) effluent provides additional efficiency improvements to the hydrolysis of the C6 solids. Here a 3 (CTS levels)×4 (AnMBR effluent levels) full factorial experiment was conducted to assess the interaction effect, if any, between the two additives. The CTS (clarified thin stillage) levels were 0, 10, and 25% of the total water in the makeup and the AnMBR effluent levels were 0, 10, 20, and 30% of the total water in the makeup. The enzyme Ctec2 from Novozymes was used at a dose of 6 mg protein per gram of glucan. A 15% total solids saccharification was run for 120 hours. The results of the experiment are illustrated at example
The results indicate that there is an interaction effect observed between CTS and AnMBR effluent when used in combination to aid the saccharification of lignocellulosic C6 solids. It appears that the maximum glucose production (80.2% glucan to glucose conversion) was observed when CTS and AnMBR effluent are used at 10% each of the total makeup water, in this embodiment. However, using AnMBR effluent at 30% total makeup water helps with the water balance in the production facility in addition to giving good glucan-to-glucose conversion of roughly 79%. Thus, depending upon water load requirements, it may be beneficial to modify the composition of the makeup water to optimize plant operations while simultaneously improving efficiency of the hydrolysis of the C6 solids.
The embodiments as disclosed and described in the application (including the FIGURES and Examples) are intended to be illustrative and explanatory of the disclosed aspects. Modifications and variations of the disclosed embodiments, for example, of the apparatus and processes employed (or to be employed) as well as of the compositions and treatments used (or to be used), are possible; all such modifications and variations are intended to be within the scope of the one or more aspects.
The word “exemplary” is used to mean serving as an example, instance, or illustration. Any embodiment or design described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Rather, use of the word exemplary is intended to present concepts in a concrete fashion, and the disclosed subject matter is not limited by such examples.
The term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” To the extent that the terms “comprises,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, for the avoidance of doubt, such terms are intended to be inclusive in a manner similar to the term “comprising” as an open transition word without precluding any additional or other elements.
This application claims the benefit of U.S. Provisional Application Ser. No. 61/433,864, filed Jan. 18, 2011, and entitled “SYSTEMS AND METHODS FOR HYDROLYSIS OF BIOMASS”, the disclosure of which is incorporated herein by reference. This application incorporates by reference the following applications: U.S. patent Ser. No. 12/716,984 entitled “SYSTEM FOR PRE-TREATMENT OF BIOMASS FOR THE PRODUCTION OF ETHANOL”, and U.S. Patent Ser. No. 61/345,486 entitled “SYSTEM FOR HYDROLYSIS OF BIOMASS TO FACILITATE THE PRODUCTION OF ETHANOL” filed May 17, 2010.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2012/021731 | 1/18/2012 | WO | 00 | 4/3/2014 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2012/099967 | 7/26/2012 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3212932 | Hess et al. | Oct 1965 | A |
4014743 | Black | Mar 1977 | A |
4029515 | Kiminki et al. | Jun 1977 | A |
4152197 | Lindahl et al. | May 1979 | A |
4168988 | Riehm et al. | Sep 1979 | A |
4342831 | Faber et al. | Aug 1982 | A |
4425433 | Neves | Jan 1984 | A |
4427453 | Reitter | Jan 1984 | A |
4432805 | Nuuttila et al. | Feb 1984 | A |
4461648 | Foody | Jul 1984 | A |
4529699 | Gerez et al. | Jul 1985 | A |
4552616 | Kauppi | Nov 1985 | A |
4612286 | Sherman et al. | Sep 1986 | A |
4668340 | Sherman | May 1987 | A |
4752579 | Arena et al. | Jun 1988 | A |
4908098 | DeLong et al. | Mar 1990 | A |
4941944 | Chang | Jul 1990 | A |
4997488 | Gould et al. | Mar 1991 | A |
5125977 | Grohmann et al. | Jun 1992 | A |
5171592 | Holtzapple et al. | Dec 1992 | A |
5221357 | Brink | Jun 1993 | A |
5328562 | Rafferty et al. | Jul 1994 | A |
5338366 | Grace et al. | Aug 1994 | A |
5366558 | Brink | Nov 1994 | A |
5370999 | Stuart | Dec 1994 | A |
5411594 | Brelsford | May 1995 | A |
5424417 | Torget et al. | Jun 1995 | A |
5498766 | Stuart et al. | Mar 1996 | A |
5536325 | Brink | Jul 1996 | A |
5562777 | Farone et al. | Oct 1996 | A |
5580389 | Farone et al. | Dec 1996 | A |
5597714 | Farone et al. | Jan 1997 | A |
5628830 | Brink | May 1997 | A |
5693296 | Holtzapple et al. | Dec 1997 | A |
5705369 | Torget et al. | Jan 1998 | A |
5711817 | Titmas | Jan 1998 | A |
5726046 | Farone et al. | Mar 1998 | A |
5733758 | Nguyen | Mar 1998 | A |
5769934 | Ha et al. | Jun 1998 | A |
5782982 | Farone et al. | Jul 1998 | A |
5820687 | Farone et al. | Oct 1998 | A |
5865898 | Holtzapple et al. | Feb 1999 | A |
5879463 | Proenca | Mar 1999 | A |
5916780 | Foody et al. | Jun 1999 | A |
5932452 | Mustranta et al. | Aug 1999 | A |
5932456 | Van Draanen et al. | Aug 1999 | A |
5972118 | Hester et al. | Oct 1999 | A |
5975439 | Chieffalo et al. | Nov 1999 | A |
6022419 | Torget et al. | Feb 2000 | A |
6090595 | Foody et al. | Jul 2000 | A |
6228177 | Torget | May 2001 | B1 |
6379504 | Miele et al. | Apr 2002 | B1 |
6419788 | Wingerson | Jul 2002 | B1 |
6423145 | Nguyen et al. | Jul 2002 | B1 |
6555350 | Ahring et al. | Apr 2003 | B2 |
6620292 | Wingerson | Sep 2003 | B2 |
6660506 | Nguyen et al. | Dec 2003 | B2 |
6692578 | Schmidt et al. | Feb 2004 | B2 |
6770168 | Stigsson | Aug 2004 | B1 |
7198925 | Foody | Apr 2007 | B2 |
7238242 | Pinatti et al. | Jul 2007 | B2 |
7354743 | Vlasenko et al. | Apr 2008 | B2 |
7455997 | Hughes | Nov 2008 | B2 |
7501025 | Bakker et al. | Mar 2009 | B2 |
7503981 | Wyman et al. | Mar 2009 | B2 |
7585652 | Foody et al. | Sep 2009 | B2 |
7604967 | Yang et al. | Oct 2009 | B2 |
7649086 | Belanger et al. | Jan 2010 | B2 |
7666637 | Nguyen | Feb 2010 | B2 |
7670813 | Foody et al. | Mar 2010 | B2 |
7709042 | Foody et al. | May 2010 | B2 |
7754456 | Penttila et al. | Jul 2010 | B2 |
7754457 | Foody et al. | Jul 2010 | B2 |
7807419 | Hennessey et al. | Oct 2010 | B2 |
7815741 | Olson | Oct 2010 | B2 |
7815876 | Olson | Oct 2010 | B2 |
7819976 | Friend et al. | Oct 2010 | B2 |
7875444 | Yang et al. | Jan 2011 | B2 |
7901511 | Griffin et al. | Mar 2011 | B2 |
8057639 | Pschorn et al. | Nov 2011 | B2 |
8057641 | Bartek et al. | Nov 2011 | B2 |
8110383 | Jönsson et al. | Feb 2012 | B2 |
8123864 | Christensen et al. | Feb 2012 | B2 |
8288600 | Bartek et al. | Oct 2012 | B2 |
8449728 | Redford | May 2013 | B2 |
8815552 | Narendranath et al. | Aug 2014 | B2 |
20020192774 | Ahring et al. | Dec 2002 | A1 |
20040060673 | Phillips et al. | Apr 2004 | A1 |
20040252580 | Nagy et al. | Dec 2004 | A1 |
20050069998 | Ballesteros Perdices et al. | Mar 2005 | A1 |
20060188965 | Wyman et al. | Aug 2006 | A1 |
20060281157 | Chotani et al. | Dec 2006 | A1 |
20080026431 | Saito et al. | Jan 2008 | A1 |
20080057555 | Nguyen | Mar 2008 | A1 |
20080277082 | Pschorn et al. | Nov 2008 | A1 |
20080295981 | Shin et al. | Dec 2008 | A1 |
20090035826 | Tolan | Feb 2009 | A1 |
20090042259 | Dale | Feb 2009 | A1 |
20090093027 | Balan | Apr 2009 | A1 |
20090098616 | Burke et al. | Apr 2009 | A1 |
20090308383 | Shin et al. | Dec 2009 | A1 |
20100003733 | Foody et al. | Jan 2010 | A1 |
20100144001 | Horton | Jun 2010 | A1 |
20100233771 | McDonald et al. | Sep 2010 | A1 |
20100285553 | Delmas et al. | Nov 2010 | A1 |
20110011391 | Burke | Jan 2011 | A1 |
20110079219 | McDonald et al. | Apr 2011 | A1 |
20110094505 | Bulla et al. | Apr 2011 | A1 |
20110171708 | Larsen | Jul 2011 | A1 |
20120129234 | McDonald et al. | May 2012 | A1 |
20120138246 | Christensen et al. | Jun 2012 | A1 |
20120201947 | Stuart | Aug 2012 | A1 |
20130065289 | Carlson | Mar 2013 | A1 |
20130143290 | Narendranath | Jun 2013 | A1 |
20130337521 | Carlson et al. | Dec 2013 | A1 |
20140024826 | Narendranath et al. | Jan 2014 | A1 |
20140209092 | McDonald et al. | Jul 2014 | A1 |
20150037859 | Bootsma | Feb 2015 | A1 |
20150072390 | Narendranath et al. | Mar 2015 | A1 |
20150128932 | Kwiatkowski et al. | May 2015 | A1 |
Number | Date | Country |
---|---|---|
0 044 658 | Jan 1982 | EP |
0 098 490 | Jan 1984 | EP |
0 159 795 | Oct 1985 | EP |
0 884 391 | Dec 1998 | EP |
1 259 466 | Nov 2002 | EP |
1 130 085 | Oct 2005 | EP |
2 397 486 | Feb 1979 | FR |
2 609 046 | Jul 1988 | FR |
WO 9408027 | Apr 1994 | WO |
WO 9429475 | Dec 1994 | WO |
WO 9508648 | Mar 1995 | WO |
WO 9814270 | Apr 1998 | WO |
WO 9856958 | Dec 1998 | WO |
WO 9906133 | Feb 1999 | WO |
WO 0014120 | Mar 2000 | WO |
WO 0061858 | Oct 2000 | WO |
WO 0073221 | Dec 2000 | WO |
WO 0132715 | May 2001 | WO |
WO 0160752 | Aug 2001 | WO |
WO 0214598 | Feb 2002 | WO |
WO 0224882 | Mar 2002 | WO |
WO 0238786 | May 2002 | WO |
WO 02051561 | Jul 2002 | WO |
WO 02067691 | Sep 2002 | WO |
WO 02070753 | Sep 2002 | WO |
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Entry |
---|
Adney, B. et al., “Measurement of Cellulase Activities”, Technical Report NREL/TP-510-42628 (2008) Cover; p. 1-8. |
Caparros, S. et al., “Xylooligosaccharides Production from Arundo donax”, J. Agric. Food Chem. 55 (2007): p. 5536-5543. |
Cort, J. et al., “Minimize Scale-Up Risk”, www.aiche.org/cep, (2010): p. 39-49. |
Demain, A.L. et al., “Cellulase, Clostridia, and Ethanol”, Microbiology and Molecular Biology Reviews 69(1) (2005): p. 124-154. |
Dien, B.S. et al., “Enzyme characterization for hydrolysis of AFEX and liquid hot-water pretreated distillers' grains and their conversion to ethanol”, Bioresource Technology 99 (2008): p. 5216-5225. |
Gibbons, W.R. et al., “Fuel Ethanol and High Protein Feed from Corn and Corn-Whey Mixtures in a Farm-Scale Plant”, Biotechnology and Bioengineering XXV (1983): p. 2127-2148. |
Goodman, B. J., “FY 1988 Ethanol from Biomass Annual Report” (1989): p. 1-458. |
Grohmann, K. et al., “Optimization of Dilute Acid Pretreatment of Biomass”, Biotechnology and Bioengineering Symp. 15 (1985): p. 59-80. |
Grohmann, K. et al., “Dilute Acid Pretreatment of Biomass at High Solids Concentrations”, Biotechnology and Bioengineering Symp. 17 (1986): p. 135-151. |
Humbird, D. et al., “Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover”, National Renewable Energy Laboratory (2011): Covers with Introduction; p. 1-114. |
Jeoh, T. “Steam Explosion Pretreatment of Cotton Gin Waste for Fuel Ethanol Production”, Thesis submitted to Virginia Polytechnic Institute and State University (1998): Cover with Introduction; p. 1-138. |
Jorgensen, H. et al., “Enzymatic conversion of lignocellulose into fermentable sugars: challenges and opportunities”, Biofuels, Bioprod. Bioref. 1 (2001): p. 119-134. |
Kumar, R. et al., “Effect of Enzyme Supplementation at Moderate Cellulase Loadings on Initial Glucose and Xylose Release from Corn Stover Solids Pretreated by Leading Technologies”, Biotechnology and Bioengineering 102(2) (2009): p. 457-467. |
Larsen, J. et al., “The IBUS Process—Lignocellulosic Bioethanol Close to a Commercial Reality”, Chem. Eng. Technol. 31(5) (2008): p. 765-772. |
Lynd, L.R. et al. “Consolidated bioprocessing of cellulosic biomass: an update”, Current Opinion in Biotechnology 16 (2005): p. 577-583. |
Mosier, N. et al., “Features of promising technologies for pretreatment of lignocellulosic biomass”, Bioresource Technology 96 (2005): p. 673-686. |
McMillan, J.D. “Processes for Pretreating Lignocellulosic Biomass: A Review”, National Renewable Energy Laboratory (1992): Covers with Introduction; p. 1-44. |
Nandini, C. et al. “Carbohydrate composition of wheat, wheat bran, sorghum and bajra with good chapatti/roti (Indian flat bread) making quality”, Food Chemistry 73 (2001): p. 197-203. |
Sanchez, O.J. et al., “Trends in biotechnological production of fuel ethanol from different feedstocks”, Bioresource Technology 99 (2008): p. 5270-5295. |
Saska, M. et al., “Aqueous Extraction of Sugarcane Bagasse Hemicellulose and Production of Xylose Syrup”, Biotechnology and Bioengineering 45 (1995): p. 517-523. |
Sepulveda-Huerta, E. et al. “Production of detoxified sorghum straw hydrolysates for fermentative purposes”, Journal of the Science of Food and Agriculture 86 (2006): p. 2579-2586. |
Spindler, D. et al., “Evaluation of Pretreated Woody Crops for the Simultaneous Saccharification and Fermentation Process”, Ethanol from Biomass. FY 1988, Annual Report (1989): p. B33-B43. |
Taherzadeh, M.J. et al., “Acid-based Hydrolysis Processes for Ethanol from Lignocellulosic Materials: A Review”, BioResources 2(3) (2007): p. 472-499. |
Taherzadeh, M.J. et al., “Enzyme-based Hydrolysis Processes for Ethanol from Lignocellulosic Materials: A Review”, BioResources 2(4) (2007): p. 707-738. |
Texeira, R.H. et al., “Ethanol Annual Report FY 1990”, (1991): p. 1-346. |
Torget, R. et al., “Dilute Acid Pretreatment of Short Rotation Woody and Herbaceous Crops”, Applied Biochemistry and Biotechnology 24/25 (1990): p. 115-126. |
Torget, R. et al., “Initial Design of a Dilute Sulfuric Acid Pretreatment Process for Aspen Wood Chips”, Solar Energy Research Institute (1988): p. 89-104. |
Torget, R. et al., “Dilute Acid Pretreatment of Corn Cobs, Corn Stover, and Short-Rotation Crops”, FY 1990 Ethanol Annual Report (1991): p. 71-82. |
Weil, J. et al., “Pretreatment of Corn Fiber by Pressure Cooking in Water”, Applied Biochemistry and Biotechnology 73 (1998): p. 1-17. |
Wyman, Charles E., “What is (and is not) vital to advancing cellulosic ethanol”, Trends in Biotechnology 25(4) (2007): p. 153-157. |
Wyman, C.E. et al., “Coordinated development of leading biomass pretreatment technologies”, Bioresource Technology 96 (2005): p. 1959-1966. |
Yang, B. et al., “Pretreatment: the key to unlocking low-cost cellulosic ethanol”, Biofuels, Bioprod. Bioref. 2 (2008): p. 26-40. |
Zhang, Y-H.P. et al., “Outlook for cellulose improvement: Screening and selection strategies”, Biotechnology Advances 24 (2006): p. 452-481. |
Zhang, Y.P. et al., “Toward an Aggregated Understanding of Enzymatic Hydrolysis of Cellulose: Noncomplexed Cellulase Systems”, Biotechnology and Bioengineering 88(7) (2004): p. 797-824. |
U.S. Appl. No. 12/716,989, filed Mar. 2010, Kwiatkowski. |
U.S. Appl. No. 12/827,948, filed Jun. 2010, Bootsma et al. |
U.S. Appl. No. 13/209,170, filed Aug. 2011, Bly et al. |
U.S. Appl. No. 14/459,977, filed Aug. 2014, Bootsma. |
U.S. Appl. No. 14/465,177, filed Aug. 2014, Narendranath et al. |
Blank, S.L. et al. “Combustion Properties of Lignin Residue From Lignocellulose Fermentation”, National Renewable Energy Laboratory, 2000, pp. 1-15. |
Bura, R. et al., “Influence of Xylan on the Enzymatic Hydrolysis of Steam-Pretreated Corn Stover and Hybrid Poplar”, Biotechnol. Prog. 25(2) (2009): p. 315-322. |
Cara, C. et al., “Influence of solid loading on enzymatic hydrolysis of steam exploded or liquid hot water pretreated olive tree biomass”, Process Biochemistry 42 (2007): p. 1003-1009. |
Gao, D. et al., “Strategy for Identification of Novel Fungal and Bacterial Glycosyl Hydrolase Hybrid Mixtures that can Efficiently Saccharify Pretreated Lignocellulosic Biomass”, Bioenerg. Res. 3 (2010): p. 67-81. |
Guo, G.L. et al., “Characterization of enzymatic saccharification for acid-pretreated lignocellulosic materials with different lignin composition”, Enzyme and Microbial Technology 45 (2009): p. 80-87. |
Haagensen , F. et al. “Enzymatic Hydrolysis and Glucose Fermentation of Wet Oxidized Sugarcane Bagasse and Rice Straw for Bioethanol Production”, RisØ-R-1517(EN), 2002, pp. 184-195. |
Kumar, S. et al., “Recent Advances in Production of Bioethanol from Lignocellulosic Biomass”, Chem. Eng. Technol. 32(4) (2009): p. 517-526. |
Li, X.L. et al., “Two cellulases, CelA and CelC, from the polycentric anaerobic fungus Orpinomyces strain PC-2 contain N-terminal docking domains for a cellulosehemicellulase complex”, Applied and Environmental Microbiology 63(12) (1997): p. 4721-4728. |
Marchal, R. et al. “Large-Scale Enzymatic Hydrolysis of Agricultural Lignocellulosic Biomass. Part 2: Conversion Into Acetone-Butanol”, Bioresource Technology 42, 1992, pp. 205-217. |
Olsson, L. et al., “Fermentation of lignocellulosic hydrolysates or ethanol production”, Enzyme Microb. Technol., 18 (1996): p. 312-331. |
Reith, J.H. et al. “Co-Production of Bio-Ethanol, Electricity and Heat From Biomass Residues”, Contribution to the 12th European Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection, Jun. 17-21, 2002, Amsterdam, the Netherlands, pp. 1-22. |
Sun, Y. et al. “Hyrdolysis of Lignocellulosic Materials for Ethanol Production: A Review”, Bioresource Technology 83, 2002, pp. 1-11. |
Thomsen, M.H. et al., “Preliminary Results on Optimization of Pilot Scale Pretreatment of Wheat Straw Used in Coproduction of Bioethanol and Electricity”, Applied Biochemistry and Biotechnology, vol. 129-132, 2006, p. 448. |
Varga, E., et al., “High Solid Simultaneous Saccharification and Fermentation of Wet Oxidized Corn Stover to Ethanol”, Biotechnol. Bioeng. 88(5), 2004, Abstract. |
Xiao, Z. et al., “Effects of Sugar Inhibition on Cellulases and β-Glucosidase During Enzymatic Hydrolysis of Softwood Substrates”, Applied Biochemistry and Biotechnology 113-116 (2004): p. 1115-1126. |
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20140234911 A1 | Aug 2014 | US |
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