Patent Application
20150101377
The invention relates to the field of land management. More specifically, an ash prepared from the filter cake and syrup co-products of a lignocellulosic biomass fermentation process is effectively used as a fertilizer and in other land surface applications such as on landfills and roads.
Materials that are renewable and available in large quantity, and that have properties making them useful to improve plant growth are desired for crop application. In addition, materials that are renewable and available in large quantity, and that have properties making them useful for stabilizing soil and other ground materials are desirable for application to landfills, road ways, and similar surfaces.
In a cellulosic ethanol process which makes use of lignocellulosic biomass as a carbon source for fermentation, whole stillage from a distillation column (beer column) is typically separated into solids (wetcake or filter cake) and liquid (thin stillage) fractions. The thin stillage is passed through evaporators producing a syrup. The filter cake and syrup are co-products of the cellulosic ethanol process. A syrup with at least about 40% solids may be burned as disclosed in commonly owned US20120102823, thereby providing energy. The filter cake may also be burned to provide energy. With increasing demand for alternative fuels using production that does not affect the food supply, these co-products will become increasingly available in large quantities.
There remains a need for additional materials that are readily available from renewable resources, which can be used in land surface applications.
Provided is a composition that contains ash from burning of co-product from a process for the production of alcohol from a lignocellulosic biomass which is useful for land applications.
Accordingly, the invention provides a composition comprising ash produced by burning lignocellulosic filter cake and optionally lignocellulosic syrup wherein the filter cake and syrup are co-products of a process for the production of alcohol from a lignocellulosic biomass.
In another aspect the invention provides a process for producing energy and a land application composition comprising:
In a further aspect the invention provides a method for enhancing a land surface comprising applying the land application composition above to a land surface.
The syrup of the invention typically has a composition comprising:
The following definitions and abbreviations are to be used for the interpretation of the claims and the specification.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
The indefinite articles “a” and “an” preceding an element or component of the invention are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore “a” or “an” should be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.
The term “invention” or “present invention” as used herein is a non-limiting term and is not intended to refer to any single embodiment of the particular invention but encompasses all possible embodiments as described in the specification and the claims.
As used herein, the term “about” modifying the quantity of an ingredient or reactant of the invention employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and liquid handling procedures used for making concentrates or use solutions in the real world; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of the ingredients employed to make the compositions or carry out the methods; and the like. The term “about” also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial mixture. Whether or not modified by the term “about”, the claims include equivalents to the quantities. In one embodiment, the term “about” means within 10% of the reported numerical value, preferably within 5% of the reported numerical value.
The term “fermentable sugar” refers to oligosaccharides and monosaccharides that can be used as a carbon source by a microorganism in a fermentation process.
The term “lignocellulosic” refers to a composition comprising both lignin and cellulose. Lignocellulosic material may also comprise hemicellulose.
The term “cellulosic” refers to a composition comprising cellulose and additional components, including hemicellulose.
The term “saccharification” refers to the production of fermentable sugars from polysaccharides.
The term “pretreated biomass” means biomass that has been subjected to pretreatment prior to saccharification. The pretreatment may take the form of physical, thermal or chemical means and combinations thereof.
The term “butanol” refers to isobutanol, 1-butanol, 2-butanol, or combinations thereof.
The term “lignocellulosic biomass” refers to any lignocellulosic material and includes materials comprising cellulose, hemicellulose, lignin, starch, oligosaccharides and/or monosaccharides. Biomass may also comprise additional components, such as protein and/or lipid. Biomass may be derived from a single source, or biomass can comprise a mixture derived from more than one source; for example, biomass could comprise a mixture of corn cobs and corn stover, or a mixture of grass and leaves. Lignocellulosic biomass includes, but is not limited to, bioenergy crops, agricultural residues, municipal solid waste, industrial solid waste, sludge from paper manufacture, yard waste, wood and forestry waste. Examples of biomass include, but are not limited to, corn cobs, crop residues such as corn husks, corn stover, grasses (including Miscanthus), wheat straw, barley straw, hay, rice straw, switchgrass, waste paper, sugar cane bagasse, sorghum plant material, soybean plant material, components obtained from milling of grains or from using grains in production processes (such as DDGS: dried distillers grains with solubles), woody material such as trees, branches, roots, wood chips, sawdust, shrubs and bushes, leaves, vegetables, fruits, flowers, empty palm fruit bunch, and energy cane.
The term “energy cane” refers to sugar cane that is bred for use in energy production. It is selected for a higher percentage of fiber than sugar.
The term “lignocellulosic biomass hydrolysate” refers to the product resulting from saccharification of lignocellulosic biomass. The biomass may also be pretreated or pre-processed prior to saccharification.
The term “lignocellulosic biomass hydrolysate fermentation broth” is broth containing product resulting from biocatalyst growth and production in a medium comprising lignocellulosic biomass hydrolysate. This broth includes components of lignocellulosic biomass hydrolysate that are not consumed by the biocatalyst, as well as the biocatalyst itself and product made by the biocatalyst.
The term “slurry” refers to a mixture of insoluble material and a liquid. A slurry may also contain a high level of dissolved solids. Examples of slurries include a saccharification broth, a fermentation broth, and a stillage.
The term “whole stillage” refers to the bottoms of a distillation. The whole stillage contains the high boilers and any solids of a distillation feed stream. Whole stillage is a type of depleted broth.
The term “thin stillage” refers to a liquid fraction resulting from solid/liquid separation of a whole stillage, fermentation broth, or product depleted fermentation broth.
The term “syrup” means a concentrated product produced from the removal of water, generally by evaporation, from thin stillage.
The term “target product” refers to any product that is produced by a microbial production host cell in a fermentation. Target products may be the result of genetically engineered enzymatic pathways in host cells or may be produced by endogenous pathways. Typical target products include but are not limited to acids, alcohols, alkanes, alkenes, aromatics, aldehydes, ketones, biopolymers, proteins, peptides, amino acids, vitamins, antibiotics, and pharmaceuticals.
The term “fermentation” refers broadly to the use of a biocatalyst to produce a target product. Typically the biocatalyst grows in a fermentation broth utilizing a carbon source in the broth, and through its metabolism produces a target product.
“Solids” refers to soluble solids and insoluble solids. Solids from a lignocellulosic fermentation process contain residue from the lignocellulosic biomass used to make hydrolysate medium.
“Volatiles” refers herein to components that will largely be vaporized in a process where heat is introduced. Volatile content is measured herein by establishing the loss in weight resulting from heating under rigidly controlled conditions to 950° C. (as in ASTM D-3175). Typical volatiles include, but are not limited to, hydrogen, oxygen, nitrogen, acetic acid, and some carbon and sulfur.
“Fixed carbon” refers herein to a calculated percentage made by summing the percent of moisture, percent of ash, and percent of volatile matter, and then subtracting that percent from 100.
“Ash content” of a material is the weight of the residue remaining after burning under controlled conditions according to ASTM D-3174.
“Sugars” as referred to in the lignocellulosic syrup composition means a total of monosaccharide and soluble oligosaccharides.
As used herein “pellets, granules, and briquettes” refers to materials in the form of pellets, granules, briquettes, beads, tablets, pills, and the like.
“Combustion enhancement material” refers to any material that is added to the combustion process of the present invention that enhances or improves the combustion. Common combustion enhancement materials include but are not limited to calcined clay and limestone.
“Emissions control material” refers to a material that is added to the combustion process of the present invention to reduce or control emissions from the combustion. Common emissions control materials include but are not limited to ammonia, hydrated lime, sodium bicarbonate, and trisodium hydrogendicarbonate di hydrate.
The present composition contains ash that is produced by burning lignocellulosic filter cake and optionally lignocellulosic syrup wherein the filter cake and syrup are co-products of a fermentation process for the production of alcohol from a lignocellulosic biomass. Thus the ash material referred to herein is lignocellulosic biomass fermentation process co-product ash.
A lignocellulosic biomass fermentation process uses lignocellulosic biomass as a source of fermentable sugars which are used as a carbon source for a biocatalyst. The biocatalyst uses the sugars in a fermentation process to produce a target product such as an alcohol. To produce fermentable sugars from lignocellulosic biomass, the biomass is treated to release sugars such as glucose, xylose, and arabinose from the polysaccharides of the biomass. Lignocellulosic biomass may be treated by any method known by one skilled in the art to produce fermentable sugars in a hydrolysate. Typically the biomass is pretreated using physical, thermal and/or chemical treatments, and saccharified enzymatically. Thermo-chemical pretreatment methods include steam explosion or methods of swelling the biomass to release sugars (see for example WO2010113129; WO2010113130). Chemical saccharification may also be used. Physical treatments for pre-processing the biomass include, but are not limited to, grinding, milling, and cutting. Physical treatments such as these may be used for particle size reduction prior to further chemical treatment. Chemical treatments include base treatment such as with strong base (ammonia or NaOH), or acid treatment (U.S. Pat. No. 8,545,633; WO2012103220). In one embodiment the biomass is treated with ammonia (U.S. Pat. No. 7,932,063; U.S. Pat. No. 7,781,191; U.S. Pat. No. 7,998,713; U.S. Pat. No. 7,915,017). These treatments release polymeric sugars from the biomass. Particularly useful is a low ammonia pretreatment where biomass is contacted with an aqueous solution comprising ammonia to form a biomass-aqueous ammonia mixture where the ammonia concentration is sufficient to maintain alkaline pH of the biomass-aqueous ammonia mixture but is less than about 12 weight percent relative to dry weight of biomass, and where dry weight of biomass is at least about 15 weight percent solids relative to the weight of the biomass-aqueous ammonia mixture, as disclosed in U.S. Pat. No. 7,932,063, which is herein incorporated by reference.
Saccharification, which converts polymeric sugars to monomeric sugars, may be either by enzymatic or chemical treatments. In one aspect, the pretreated biomass is contacted with a saccharification enzyme consortium under suitable conditions to produce fermentable sugars. Prior to saccharification, the pretreated biomass may be brought to the desired moisture content and treated to alter the pH, composition or temperature such that the enzymes of the saccharification enzyme consortium will be active. The pH may be altered through the addition of acids in solid or liquid form. Alternatively, carbon dioxide (CO2), which may be recovered from fermentation, may be utilized to lower the pH. For example, CO2 may be collected from a fermenter and fed into the pretreatment product headspace in the flash tank or bubbled through the pretreated biomass if adequate liquid is present while monitoring the pH, until the desired pH is achieved. The temperature is brought to a temperature that is compatible with saccharification enzyme activity, as noted below. Typically suitable conditions may include temperature between about 40° C. and 50° C. and pH between about 4.8 and 5.8.
Enzymatic saccharification of cellulosic or lignocellulosic biomass typically makes use of an enzyme composition or blend to break down cellulose and/or hemicellulose and to produce a hydrolysate containing sugars such as, for example, glucose, xylose, and arabinose. Saccharification enzymes are reviewed in Lynd, L. R., et al. (Microbiol. Mol. Biol. Rev., 66:506-577, 2002). At least one enzyme is used, and typically a saccharification enzyme blend is used that includes one or more glycosidases. Glycosidases hydrolyze the ether linkages of di-, oligo-, and polysaccharides and are found in the enzyme classification EC 3.2.1.x (Enzyme Nomenclature 1992, Academic Press, San Diego, Calif. with Supplement 1 (1993), Supplement 2 (1994), Supplement 3 (1995, Supplement 4 (1997) and Supplement 5 [in Eur. J. Biochem., 223:1-5, 1994; Eur. J. Biochem., 232:1-6, 1995; Eur. J. Biochem., 237:1-5, 1996; Eur. J. Biochem., 250:1-6, 1997; and Eur. J. Biochem., 264:610-650 1999, respectively]) of the general group “hydrolases” (EC 3.). Glycosidases useful in saccharification can be categorized by the biomass components they hydrolyze. Glycosidases useful in saccharification may include cellulose-hydrolyzing glycosidases (for example, cellulases, endoglucanases, exoglucanases, cellobiohydrolases, β-glucosidases), hemicellulose-hydrolyzing glycosidases (for example, xylanases, endoxylanases, exoxylanases, β-xylosidases, arabino-xylanases, mannases, galactases, pectinases, glucuronidases), and starch-hydrolyzing glycosidases (for example, amylases, α-amylases, β-amylases, glucoamylases, α-glucosidases, isoamylases). In addition, it may be useful to add other activities to the saccharification enzyme consortium such as peptidases (EC 3.4.x.y), lipases (EC 3.1.1.x and 3.1.4.x), ligninases (EC 1.11.1.x), or feruloyl esterases (EC 3.1.1.73) to promote the release of polysaccharides from other components of the biomass. It is known in the art that microorganisms that produce polysaccharide-hydrolyzing enzymes often exhibit an activity, such as a capacity to degrade cellulose, which is catalyzed by several enzymes or a group of enzymes having different substrate specificities. Thus, a “cellulase” from a microorganism may comprise a group of enzymes, one or more or all of which may contribute to the cellulose-degrading activity. Commercial or non-commercial enzyme preparations, such as cellulase, may comprise numerous enzymes depending on the purification scheme utilized to obtain the enzyme. Many glycosyl hydrolase enzymes and compositions thereof that are useful for saccharification are disclosed in WO 2011/038019. Additional enzymes for saccharification include, for example, glycosyl hydrolases that hydrolyze the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a noncarbohydrate moiety.
Saccharification enzymes may be obtained commercially. Such enzymes include, for example, Spezyme® CP cellulase, Multifect® xylanase, Accelerase® 1500, Accellerase® DUET, and Accellerase® Trio™ (Dupont™/Genencor®, Wilmington, Del.), and Novozyme-188 (Novozymes, 2880 Bagsvaerd, Denmark). In addition, saccharification enzymes may be unpurified and provided as a cell extract or a whole cell preparation. The enzymes may be produced using recombinant microorganisms that have been engineered to express one or more saccharifying enzymes. For example, an H3A protein preparation that may be used for saccharification of pretreated cellulosic biomass is an unpurified preparation of enzymes produced by a genetically engineered strain of Trichoderma reesei, which includes a combination of cellulases and hemicellulases and is described in WO 2011/038019, which is incorporated herein by reference.
Chemical saccharification treatments may be used and are known to one skilled in the art, such as treatment with mineral acids including HCl and H2SO4 (U.S. Pat. No. 5,580,389; WO2011002660).
Sugars such as glucose, xylose and arabinose are released by saccharification of lignocellulosic biomass and these monomeric sugars provide a carbohydrate source for a biocatalyst used in a fermentation process. The sugars are present in a biomass hydrolysate that is used as fermentation medium. The fermentation medium may be composed solely of hydrolysate, or may include components additional to the hydrolysate such as sorbitol or mannitol at a final concentration of about 5 mM as described in U.S. Pat. No. 7,629,156, which is incorporated herein by reference. The biomass hydrolysate typically makes up at least about 50% of the fermentation medium. Typically about 10% of the final volume of fermentation broth is seed inoculum containing the biocatalyst.
The medium comprising hydrolysate is fermented in a fermenter, which is any vessel that holds the hydrolysate fermentation medium and at least one biocatalyst, and has valves, vents, and/or ports used in managing the fermentation process.
Any biocatalyst that produces a target product utilizing glucose and preferably also xylose, either naturally or through genetic engineering, may be used for fermentation of the fermentable sugars in the biomass hydrolysate made from lignocellulosic biomass. Target products that may be produced by fermentation include, for example, acids, alcohols, alkanes, alkenes, aromatics, aldehydes, ketones, biopolymers, proteins, peptides, amino acids, vitamins, antibiotics, and pharmaceuticals. Alcohols include, but are not limited to methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, propanediol, butanediol, glycerol, erythritol, xylitol, mannitol, and sorbitol. Acids may include acetic acid, formic acid, lactic acid, propionic acid, 3-hydroxypropionic acid, butyric acid, gluconic acid, itaconic acid, citric acid, succinic acid, 3-hydroxypropionic acid, fumaric acid, maleic acid, and levulinic acid. Amino acids may include glutamic acid, aspartic acid, methionine, lysine, glycine, arginine, threonine, phenylalanine and tyrosine. Additional target products include methane, ethylene, acetone and industrial enzymes.
The fermentation of sugars in biomass hydrolysate to target products may be carried out by one or more appropriate biocatalysts, that are able to grow in medium containing biomass hydrolysate, in single or multistep fermentations. Biocatalysts may be microorganisms selected from bacteria, filamentous fungi and yeast. Biocatalysts may be wild type microorganisms or recombinant microorganisms, and may include, for example, organisms belonging to the genera of Escherichia, Zymomonas, Saccharomyces, Candida, Pichia, Streptomyces, Bacillus, Lactobacillus, and Clostridiuma. Typical examples of biocatalysts include recombinant Escherichia coli, Zymomonas mobilis, Bacillus stearothermophilus, Saccharomyces cerevisiae, Clostridia thermocellum, Thermoanaerobacterium saccharolyticum, and Pichia stipitis. To grow well and have high product production in a lignocellulosic biomass hydrolysate fermentation broth, a biocatalyst may be selected or engineered to have higher tolerance to inhibitors present in biomass hydrolysate such as acetate. For example, the biocatalyst may produce ethanol as a target product, such as production of ethanol by Zymomonas mobilis as described in U.S. Pat. No. 8,247,208, which is incorporated herein by reference.
Fermentation is carried out with conditions appropriate for the particular biocatalyst used. Adjustments may be made for conditions such as pH, temperature, oxygen content, and mixing. Conditions for fermentation of yeast and bacterial biocatalysts are well known in the art.
In addition, saccharification and fermentation may occur at the same time in the same vessel, called simultaneous saccharification and fermentation (SSF). In addition, partial saccharification may occur prior to a period of concurrent saccharification and fermentation in a process called HSF (hybrid saccharification and fermentation).
For large scale fermentations, typically a smaller culture of the biocatalyst is first grown, which is called a seed culture. The seed culture is added to the fermentation medium as an inoculum typically in the range from about 2% to about 20% of the final volume.
Typically fermentation by the biocatalyst produces a fermentation broth containing the target product made by the biocatalyst. For example, in an ethanol process the fermentation broth may be a beer containing from about 6% to about 10% ethanol. In addition to target product, the fermentation broth contains water, solutes, and solids from the hydrolysate medium and from biocatalyst metabolism of sugars in the hydrolysate medium. Typically the target product is isolated from the fermentation broth producing a depleted broth, which may be called whole stillage. For example, when ethanol is the product, the broth is distilled, typically using a beer column, to generate an ethanol product stream and a whole stillage. Distillation may be using any conditions known to one skilled in the art including at atmospheric or reduced pressure. The distilled ethanol is further passed through a rectification column and molecular sieve to recover an ethanol product. The target product may alternatively be removed in a later step such as from a solid or liquid fraction after separation of fermentation broth.
The lignocellulosic syrup co-product of a lignocellulosic biomass fermentation process is produced from the fermentation broth or depleted fermentation broth. An example of syrup production is disclosed in US20120102823, which is incorporated herein by reference. The broth or depleted broth, such as whole stillage, is separated into solid and liquid streams, where the liquid stream is called thin stillage. Various filtration devices may be used such as a belt filter, belt press, screw press, drum filter, disc filter, Nutsche filter, filter press or filtering centrifuge. Filtration may be aided such as by application of vacuum, pressure, or centrifugal force. To improve efficiency of filtration, a heat treatment may be used as disclosed in commonly owned and co-pending US20120178976, which is incorporated herein by reference.
Following liquid/solid separation of a lignocellulosic biomass hydrolysate fermentation broth or depleted broth, the solids fraction, or filter cake (also called wetcake), may be burned to supply energy to the production process. The lignocellulosic filter cake may be dried prior to burning, such as by air drying, to reduce moisture. The wet lignocellulosic filter cake composition contains from about 35% to about 65% moisture (may have about 35%, 40%, 45%, 50%, 55%, 60%, or 65% moisture), from about 20% to about 75% volatiles (may have about 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75% volatiles), from about 35% to about 65% solids (may have about 35%, 40%, 45%, 50%, 55%, 60%, or 65% solids), from about 1% to about 30% ash (may have about 1%, 3%, 5%, 10%, 15%, 20%, 25%, or 30% ash), from about 5% to about 20% fixed carbon, and it has an energy value of about 2,000 to about 9,000 BTU/lb (may have about 2,000, 2,500, 3,000, 3,500, 4,000, 4,500, 5,000, 5,500, 6,000, 6,500, 7,000, 7,500 8,000, 8,500, or 9,000 BTU/lb). The volatile content is measured by establishing the loss in weight resulting from heating under rigidly controlled conditions to 950° C. (as in ASTM D-3175). Typical volatiles include hydrogen, oxygen, nitrogen, acetic acid, and some carbon and sulfur. Ash is determined by weighing the residue remaining after burning under controlled conditions according to ASTM D-3174. The amount of fixed carbon is calculated by adding the percentages of moisture, ash, and volatiles, and then subtracting from 100. The full upper range of BTU/lb is typically achieved with drying.
The liquid fraction is further purified by evaporation producing water that may be recycled and a syrup. Prior to evaporation, a portion of the liquid fraction may be recycled for use as back set, which may be added at any point in the process where water is needed, such as in pretreatment, saccharification, or biocatalyst seed production. Evaporation may be in any evaporation system, such as falling film, rising film, forced circulation, plate or mechanical and thermal vapor recompression systems. Evaporation may be continuous or batch and may use a multi-effect evaporator. The evaporated water may be recycled in the overall lignocellulosic biomass hydrolysate fermentation process.
The remaining material after evaporation is a syrup which is the present syrup co-product of a process for the production of alcohol from a lignocellulosic biomass. In one embodiment the syrup composition contains from about 40% to about 70% solids (may have about 40%, 45%, 50%, 55%, 60%, 65%, or 70% solids), from about 10 g/l to 30 g/l of acetamide, at least about 40 g/l of sugars, a density of about 1 to about 2 g/cm3, and viscosity less than 500 SSU at 100° F. (38° C.). “SSU” is Saybolt Universal Viscosity in Seconds. The extent of evaporation may be modulated to achieve the desired solids content. When the pretreatment process used to prepare the biomass for saccharification is a process that uses ammonia, the lignocellulosic syrup contains at least about 5 g/l of ammonia.
In the present process, energy and lignocellulosic ash are produced by combusting lignocellulosic filter cake and optionally lignocellulosic syrup that are co-products of a process for the production of alcohol from a lignocellulosic biomass. In one embodiment the syrup contains components as given above. In one embodiment the filter cake contains components as given above. In addition, at least one combustion enhancement material is added during combustion. Any appropriate combustion enhancement material may be added, such as sand, calcium carbonate, and calcined clay. The combustion enhancement material is added in an amount to improve combustion. Thermal energy produced during the combustion is recovered in the form of steam.
In one embodiment is a composition comprising ash from the combusted lignocellulosic filter cake and optional lignocellulosic syrup. In one embodiment ash of at least one combusted combustion enhancement material is present in the composition. The produced lignocellulosic ash is a land application composition.
Typically the lignocellulosic filter cake, optional lignocellulosic syrup, and combustion enhancing material are injected into a combustion vessel such as a furnace or boiler. These components may be injected separately, or together in any combination. In one embodiment both lignocellulosic filter cake and lignocellulosic syrup are combusted to produce energy and ash, and the filter cake and syrup are added in a ratio that is at least about 2:1 of filter cake to syrup.
In one embodiment, at least one emissions control material is added downstream of the combustion process. Any appropriate emissions control material may be added, such as ammonia, hydrated lime, sodium bicarbonate, and trisodium hydrogendicarbonate di hydrate (trona).
In one embodiment the lignocellulosic filter cake and optional lignocellulosic syrup are combusted in the presence of at least one additional type of fuel. Any type of solid fuel may be used such as coal or another biomass fuel. Thus the resulting ash contains ash from combusted lignocellulosic filter cake and optional syrup, as well as ash from combusting at least one additional type of solid fuel.
Lignocellulosic ash may be collected at various locations that are available in the equipment used for combustion. Ash may be collected as boiler dropout hopper ash, cyclone ash, baghouse ash, and/or clinker ash. These types of ash may be used in the land application composition individually or in any combination, and they may be combined in any ratios.
In one embodiment, additional lignocellulosic syrup that is a co-product of a process for the production of alcohol from a lignocellulosic biomass is added to the lignocellulosic ash to improve handling, storage, and application of the resulting land application composition. In one embodiment the additional syrup is mixed with the ash in a ratio of syrup to the ash that is between about 1:1 and 1:9. The ratio may be about 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, or 1:9. In one embodiment is a composition comprising the additional syrup and the ash. In various embodiments the composition has a ratio of additional syrup to ash of any of these ratios.
In one embodiment the land application composition is processed to form pellets, granules or briquettes. The land application composition formed into pellets, granules, or briquettes provides a conveniently handled material. Processing may include treatments such as heating, compressing, extruding, pelleting, molding, and/or drying. Various shapes may be formed such as briquettes, pellets, granules, irregular shapes, and the like. For example, the mixture may be passed through an extruder at an elevated temperature, then a pelletizer, then dried, forming hardened fuel pellets. Any type of extruder that pushes or draws semisoft solids through a die may be used, as known to one of skill in the art. Extrusion may be performed at elevated temperature and/or elevated pressure. A pelletizer may be used to reduce volume and increase density of the lignocellulosic fuel composition, either alone or combined with extrusion, and to form the material into pellets.
In various embodiments the land application composition is applied to a surface such as an unpaved road, landfill, field, or a site needing at least one of fill material and stabilization. The land application composition can be used to fill in areas where fill dirt could be used, such as to fill in holes or around foundations. It can act as a surface stabilizer to improve the strength and durability of the surface, and/or to prevent erosion. The land application composition can be applied to an unpaved road or landfill to cover and/or stabilize the surface. In a landfill, it can be used to form a barrier between the confines of the landfill and natural elements such as wind and rain and also be used to enhance moisture permeation properties. The land application composition can be applied to a road in preparation for surfacing or resurfacing, where it may act as a base for surfacing. It may be applied during grading of the surface.
In various embodiments the land application composition is mixed or formulated with at least one of soil, clay, and the like prior to applying to a land surface.
The land application composition may be applied to a field to stabilize soil and/or act as a fertilizer. The land application composition contains mineral nutrients needed for plant growth such as sulfur, potassium, phosphorus, magnesium, and iron. In addition, calcium is abundant, particularly when calcium carbonate is added to a lignocellulosic filter cake, and optional lignocellulosic syrup, as part of the combustion process. Calcium is present as calcium carbonate and calcium oxide, which can be components of fertilizer.
The present invention is further defined in the following Examples. It should be understood that these Examples, while indicating preferred embodiments of the invention, are given by way of illustration only. From the above discussion and these Examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various uses and conditions.
The meaning of abbreviations used is as follows: wt is weight; lbs. is pounds.
Accellerase® 1500 (A1500) and Multifect® Xylanase are obtained from Danisco U.S. Inc., Genencor, International (Rochester, N.Y.).
Strain 229: A Trichoderma reesei strain, derived from RL-P37 (Sheir-Neiss and Montenecourt, 1984, Appl. Microbiol. Biotechnol. 20:46-53) through mutagenesis and selection for high cellulase production, was co-transformed with the β-glucosidase expression cassette (cbh1 promoter, T. reesei β-glucosidase) gene, cbh1 terminator, and amdS marker), and the endoxylanase expression cassette (cbh1 promoter, T. reesei xyn3, and cbh1 terminator) using PEG mediated transformation (Penttila et al., 1987, Gene 61(2):155-64). Numerous transformants were isolated and examined for β-glucosidase and endoxylanase production. One transformant, referred to as T. reesei strain #229, was used in certain studies described herein.
Strain H3A: T. reesei strain #229 was co-transformed with the β-xylosidase Fv3A expression cassette (cbh1 promoter, Fv3A gene, cbh1 terminator, and alsR marker), the β-xylosidase Fv43D expression cassette (egl1 promoter, Fv43D gene, native Fv43D terminator), and the Fv51A α-arabinofuranosidase expression cassette (egl1 promoter, Fv51A gene, Fv51A native terminator) using electroporation. Transformants were selected on Vogels agar plates containing chlorimuron ethyl. Numerous transformants were isolated and examined for β-xylosidase and L-α-arabinofuranosidase production. T. reesei integrated expression strain H3A, which recombinantly expresses T. reesei β-glucosidase 1, T. reesei xyn3, Fv3A, Fv51A, and Fv43D was isolated.”
Extra cellular protein produced during fermentation of strain H3A was separated from the cell mass by centrifugation, concentrated by membrane-ultrafiltration through a Millipore 10 kD molecular cut off weight membrane and pH adjusted to 4.8. Total protein was determined using a modified Biuret method as modified by Weichselbaum and Gornall using Bovine Serum Albumin as a calibrator (Weichselbaum, 1960, Amer. J. Clin. Path. 16:40; Gornall et al., 1949 J. Biol. Chem 177:752). This H3A extracellular protein preparation, called herein H3A protein, was used as a combination cellulase and hemicellulase preparation effecting complex carbohydrate hydrolysis during SSF.
Origin of the Zymomonas mobilis Strains for Fermentation
A lignocellulosic biomass hydrolysate fermentation broth may be made using alternative biocatalysts. Exemplary strains are described below. As an alternative, strain ZW658, deposited as ATCC #PTA-7858, may be used to produce a lignocellulosic biomass hydrolysate fermentation broth for processing.
Zymomonas mobilis strain ZW705 was produced from strain ZW801-4 by the methods detailed in U.S. Pat. No. 8,247,208, which is herein incorporated by reference, as briefly restated here. Cultures of Z. mobilis strain ZW801-4 were grown under conditions of stress as follows. ZW801-4 is a recombinant xylose-utilizing strain of Z. mobilis that was described in U.S. Pat. No. 7,741,119, which is herein incorporated by reference. Strain ZW801-4 was derived from strain ZW800, which was derived from strain ZW658, all as described in U.S. Pat. No. 7,741,119. ZW658 was constructed by integrating two operons, PgapxylAB and Pgaptaltkt, containing four xylose-utilizing genes encoding xylose isomerase, xylulokinase, transaldolase and transketolase, into the genome of ZW1 (ATCC #31821) via sequential transposition events, and followed by adaptation on selective media containing xylose. ZW658 was deposited as ATCC #PTA-7858. In ZW658, the gene encoding glucose-fructose oxidoreductase was insertionally-inactivated using host-mediated, double-crossover, homologous recombination and spectinomycin resistance as a selectable marker to create ZW800. The spectinomycin resistance marker, which was bounded by loxP sites, was removed by site specific recombination using Cre recombinase to create ZW801-4.
A continuous culture of ZW801-4 was run in 250 ml stirred, pH and temperature controlled fermentors (Sixfors; Bottmingen, Switzerland). The basal medium for fermentation was 5 g/L yeast extract, 15 mM ammonium phosphate, 1 g/L magnesium sulfate, 10 mM sorbitol, 50 g/L xylose and 50 g/L glucose. Adaptation to growth in the presence of high concentrations of acetate and ammonia was effected by gradually increasing the concentration of ammonium acetate added to the above continuous culture media while maintaining an established growth rate as measured by the specific dilution rate over a period of 97 days. Ammonium acetate was increased to a concentration of 160 mM. Further increases in ammonium ion concentration were achieved by addition of ammonium phosphate to a final total ammonium ion concentration of 210 mM by the end of 139 days of continuous culture. Strain ZW705 was isolated from the adapted population by plating to single colonies and amplification of one chosen colony.
Strain AR3 7-31 was produced from strain ZW705 by further adaptation for growth in corn cob hydrolysate medium as disclosed in U.S. Pat. No. 8,476,048, which is incorporated herein by reference. ZW705 was grown in a turbidostat (U.S. Pat. No. 6,686,194; Heurisko USA, Inc. Newark, Del.), which is a continuous flow culture device where the concentration of cells in the culture was kept constant by controlling the flow of medium into the culture, such that the turbidity of the culture was kept within specified narrow limits. Two media were available to the growing culture in the continuous culture device, a resting medium (Medium A) and a challenge medium (Medium B). A culture was grown on resting medium in a growth chamber to a turbidity set point and then was diluted at a dilution rate set to maintain that cell density. Dilution was performed by adding media at a defined volume once every 10 minutes. When the turbidostat entered a media challenge mode, the choice of adding challenge medium or resting medium was made based on the rate of return to the set point after the previous media addition. The steady state concentration of medium in the growth chamber was a mix of Medium A and Medium B, with the proportions of the two media dependent upon the rate of draw from each medium that allowed maintenance of the set cell density at the set dilution rate. A sample of cells representative of the population in the growth chamber was recovered from the outflow of the turbidostat (in a trap chamber) at weekly intervals. The cell sample was grown once in MRM3G6 medium and saved as a glycerol stock at −80° C.
ZW705 was grown to an arbitrary turbidity set point that dictated that the culture use all of the glucose and approximately half of the xylose present in the incoming media to meet the set point cell density at the set dilution rate. Using resting medium that was 50% HYAc/YE and 50% MRM3G6.5×4.5NH4Ac12.3 and challenge medium that was HYAc/YE. A strain isolated after 3 weeks was used in another round of turbidostat adaptation using HYAc/YE as the resting medium and HYAc/YE+9 weight % ethanol as the challenge medium. Strain AR3 7-31 was isolated after 2 weeks and was characterized as a strain with improved xylose and glucose utilization, as well as improved ethanol production, in hydrolysate medium. By sequence analysis, AR3 7-31 was found to have a mutation in the Zymomonas mobilis genome ORF encoding a protein having characteristics of a membrane transport protein, and annotated as encoding a fusaric acid resistance protein.
Corn stover is milled to ⅜″ (0.95 cm). Pretreatment is at 140° C. with 14% NH3 and 65% solids for 60 min. Saccharification is at 47° C., pH 5.3, with 7.8 mg/g glucan+xylan of an enzyme consortium, for 96 hr. Saccharification enzymes are a mix of cellulases and hemicellulases expressed in a Trichoderma reesei strain H3A as described above. The resulting hydrolysate is used in fermentation. 10 mM sorbitol is added to the hydrolysate making the fermentation medium, and the pH is adjusted to 5.8.
For the seed, first frozen strain Zymomonas mobilis AR3 7-31 stock is grown in MRM3G6 (10 g/L BBL yeast extract, 2 g/L KH2PO4, 1 g/L MgSO4*7H2O, 60 g/L glucose) at 33° C., without shaking for 8 hr as a revival culture. MRM3G10 medium (same as MRM3G6 but with 100 g/L glucose) is inoculated with revival culture, and incubated at 33° C. with shaking for 14-16 hr. Growth is to an OD600 between 1.5 and 3.1. The entire culture is used to inoculate a seed fermenter to an initial OD600 of approximately 0.05.
The seed fermentation is carried out in 10 g/L yeast extract, 2 g/L KH2PO4, 5 g/L MgSO4*7H2O, 10 mM sorbitol, and 150 g/L glucose. Seed fermentation is performed at 33° C. and pH 5.5. Seed is harvested after first observation of glucose reduction to less than 50 g/L, with glucose measured by using a YSI 2700 SELECT™ Biochemistry Analyzer (YSI Life Sciences; Yellow Springs, Ohio).
The seed is added to the hydrolysate medium in the fermenter. Fermentations are carried out at 30° C.-33° C. for 48-72 hr.
The fermentation broth is distilled to recover ethanol and the remaining whole stillage is filtered. The liquid fraction is passed through evaporators removing overhead water, and producing a lignocellulosic syrup. The solids fraction is a lignocellulosic filter cake.
Inductively Coupled Plasma-Atomic Emission Spectrometry: An aqueous sample solution is pumped through a nebulizer with argon gas into hot plasma and atomized. The sample is excited, emitting light wavelengths characteristic of its elements. A mirror reflects the light through the spectrometer on a grating that separates the elements' wavelengths onto photomultiplier detectors. RSD: 25% LOD: <1 ppm
Aqueous samples may only require dilution before introduction into the instrument. Non-aqueous solutions, solutions containing organic compounds and solid materials require acid digestion (hydrochloric and/or nitric acids), microwave digestion or bomb digestion. Oxygen Bomb Combustion for organics. Fusion, Base or Acid dissolution for inorganics.
One gram of sample is weighed into a bomb cup containing 0.1 g Na2CO3 and 5 ml of DI water. The sample is fused and placed in an oxygen bomb. The bomb is charged with 20 Torr of oxygen placed in a water bath and then detonated. The bomb is cooled to room temperature and removed from the bath. The bomb is brought back to ambient pressure and opened. The inside of the bomb is washed with DI water and transferred to a volumetric flask. 5 ml of HCl is added to acidify the solution and the sample is diluted to volume and analyzed.
Ag, Al, As, Au, B, Ba, Be, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Ge, Hf, Hg, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Rb, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tc, Te, Th, Ti, Tl, Tm, V, U, W, Y, Yb, Zn, Zr.
The sample is combusted in a pure oxygen environment; the gases are carried through the system by helium, converted and measured as CO2, H2O, N2 and SO2. The product gases are separated under steady-state conditions and are detected by Thermal Conductivity or IR. The C, H and N methodologies based on the Pregl (CH) and Dumas (N). (CHN: ASTM D5291). Precision: +/−0.30% LOD: <0.10%
Wet filter cake was fed to a combustor (furnace) and syrup was simultaneously separately injected to the same combustor in order to use the materials as fuel and recover thermal energy in the form of steam. The ratio of filter cake to syrup was on the order of 65% filter cake with 35% syrup on an as fired weight basis. Combustion enhancement materials comprising calcined clay and limestone were also fed to the combustion zone either with the filter cake or separately. The combustion materials were fed into the furnace both prior to and during fuel firing.
Emissions control materials were injected downstream of the combustion process. These materials were ammonia, limestone, and sodium bicarbonate, added to the extent required to meet emission requirements.
Ash was collected at various locations as clinker ash from the bed or grate, boiler or flue gas duct dropout hoppers, cyclone ash from cyclone collectors, and baghouse ash from a baghouse particulate collection device. Ash and unspent combustion enhancement and emission control materials along with reacted emission control materials were collected in separate or common ash collection systems.
Ash samples representing cyclone, baghouse and clinker material were subjected to inductively coupled plasma-atomic emission spectrometry (ICP-AES) and combustion (CHN) analyses to determine elemental composition. Results are given in table 1. Results of elemental analyses indicated that the ash contained several components, having potential value as an agricultural soil amendment, including Ca, K and S.
1BDL = Below detectable limit (20 ppm)
Ash samples representing cyclone, baghouse and clinker material were subjected to powder x-ray diffraction analysis to identify and quantify crystalline phases. Ash samples were prepared by grinding in a mortar and pestle. The resulting powders from each sample were pressed into a bulk sample holder with a glass slide for analysis. Data were collected by a coupled Theta:two-Theta scan on a Rigaku Ultima-III diffractometer equipped with copper x-ray tube, parafocusing optics, computer-controlled slits, and a diffracted beam monochromator. X-ray diffraction intensities were plotted as squared counts to emphasize weaker peaks, and peak shapes and positions were compared to the ICDD/ICSD diffraction database to identify the crystalline phases present in each sample. Quantitative analysis of ash samples was performed using WPF (whole pattern fitting). Results are given in Table 2.
Results of compositional analysis confirmed the presence of compounds containing Ca, K and S, and further identified significant concentrations of several compounds with capacity to increase soil pH, including CaCO3, CaO and Ca(OH)2.
Lab tests were conducted to assess K availability and lime (CaCO3) equivalency (CCE) of ash. Both of these measures are directly related to the value of the ash as a soil amendment for crop production. The CCE of ash was determined following ASTM International C25-11 (section 33). Standard Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated Lime (ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, Pa. 19428-2959, United States.). Potassium availability was determined using a Mehlich 3 acid extraction (Mehlich, A. 1984. Mehlich-3 soil test extractant: a modification of Mehlich-2 extractant. Commun. Soil Sci. Plant Anal. 15(12): 1409-1416.).
Lab tests indicated that K present in baghouse ash was highly soluble (90-100%), and that K present in cyclone ash was moderately soluble (50-70%). The effective calcium carbonate equivalency value of both cyclone ash ranged from 50-70%, on average.
Field tests are conducted to evaluate the K, S and CaCO3 (lime) value of ash when used as a soil application for corn production. Ash applied in field trials was composed of 80% cyclone material and 20% baghouse material. Experimental treatments included varying rates of ash and comparable fertilizer materials that were applied to the soil at varying rates prior to corn planting, and are listed in Table 3.
1Effective calcium carbonate equivalent
Each treatment was replicated four times in a randomized complete block (RCB) experimental design. Individual plots were 10×12 ft. in area. Soil and crop samples are collected and analyzed.
This application claims the benefit of U.S. Provisional Application 61/889,061, filed Oct. 10, 2013 which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61889061 | Oct 2013 | US |
