# US 2014/0154759 A1 · Processes for producing low-ash biomass for combustion or pellets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154759 A1 - Document ID: US20140154759A1 - Status: Published application - Kind: A1 - Application number: 14/173,239 - Filed: 2014-02-05 - Published: 2014-06-05 - Earliest claimed: 2012-03-19 - Assignees: API Intellectual Property Holdings, LLC - Applicants: API Intellectual Property Holdings, LLC - Inventors: Theodora RETSINA; Vesa PYLKKANEN - Web page: https://patentgrep.com/patent/US20140154759A1 ## CPC - C05F 17/00: Preparation of fertilisers characterised by biological or biochemical treatment steps, e.g. composting or fermentation - C08B 1/003: {Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids (solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02)} - C08H 8/00: Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} - C10L 5/44: on vegetable substances - C12P 7/06: Ethanol, i.e. non-beverage - C12P 7/10: substrate containing cellulosic material - C12P 7/16: Butanols - C12P 7/54: Acetic acid (vinegar C12J) - C12P 7/56: Lactic acid - C12P 19/14: produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase} - C13K 1/02: obtained by saccharification of cellulosic materials (manufacture of fodder A23K10/32) - F23G 7/12: of plastics, e.g. rubber - C10L 2290/08: Drying or removing water - C10L 2290/10: Recycling of a stream within the process or apparatus to reuse elsewhere therein - C10L 2290/544: Extraction for separating fractions, components or impurities during preparation or upgrading of a fuel - C12P 2201/00: Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis - Y02E 50/10: Biofuels, e.g. bio-diesel - Y02E 50/30: Fuel from waste, e.g. synthetic alcohol or diesel - Y02P 20/145: the feedstock being materials of biological origin - Y02W 30/40: Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse - C05F: ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE - C08B: POLYSACCHARIDES; DERIVATIVES THEREOF (polysaccharides containing less than six saccharide radicals attached to each other by glycosidic linkages C07H; fermentation or enzyme-using processes C12P19/00; sugar industry C13; production of cellulose D21) - C08H: DERIVATIVES OF NATURAL MACROMOLECULAR COMPOUNDS (polysaccharides C08B; natural rubber C08C; natural resins or their derivatives C09F; bituminous materials C10) - C10L: FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS - C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)} - C13K: SACCHARIDES OBTAINED FROM NATURAL SOURCES OR BY HYDROLYSIS OF NATURALLY OCCURRING DISACCHARIDES, OLIGOSACCHARIDES OR POLYSACCHARIDES (chemically synthesised sugars or sugar derivatives C07H; polysaccharides, e.g. starch, derivatives thereof C08B; malt C12C; fermentation or enzyme-using processes for preparing compounds containing saccharide radicals C12P19/00; production of sucrose C13B) - F23G: CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT ## Abstract This invention provides processes and apparatus to convert biomass, including wood and agricultural residues, into low-ash biomass pellets for combustion, alone or in combination with another solid fuel. Some embodiments provide processes for producing low-ash biomass from cellulosic biomass, comprising providing an aqueous extraction solution with acetic acid; extracting the feedstock to produce an extract liquor containing soluble ash, hemicellulosic oligomers, acetic acid, dissolved lignin, and cellulose-rich solids; dewatering and drying the cellulose-rich, lignin-rich solids to produce a low-ash biomass; hydrolyzing the hemicellulosic oligomers to produce hemicellulosic sugars, wherein additional acetic acid is generated; removing a vapor stream comprising vaporized acetic acid from the extract; and recycling the vapor or its condensate to provide some starting acetic acid for the extraction solution. The disclosed processes can produce clean power from biomass. Co-products may include fermentable sugars, fermentation products such as ethanol, fertilizers, and lignin. ## Claims ### Claim 1 A process for producing low-ash biomass from cellulosic biomass, said process comprising: (a) providing a feedstock comprising cellulosic biomass; (b) providing an extraction solution comprising steam and/or hot water, and starting acetic acid; (c) treating said feedstock with said extraction solution under effective extraction conditions to produce an extract liquor containing soluble ash, hemicellulosic oligomers, acetic acid, dissolved lignin, and cellulose-rich solids; (d) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce dewatered solids containing cellulose and lignin; (e) hydrolyzing said hemicellulosic oligomers contained in said extract liquor, under effective hydrolysis conditions, to produce hemicellulosic sugars, wherein said effective hydrolysis conditions release acetyl groups to generate additional acetic acid; (f) removing a vapor stream comprising water and vaporized acetic acid from said extract liquor in at least one evaporation stage at a pH of 4.8 or less, to produce a concentrated extract liquor comprising said hemicellulosic sugars; (g) recycling at least a portion of said vapor stream from step (f), or a condensed form thereof, back to step (b) to provide at least some of said starting acetic acid for said extraction solution and to provide heat for step (c); and (h) drying said dewatered solids to produce said low-ash biomass. ### Claim 2 (depends on 1) The process of claim 1, wherein said extraction solution comprises steam in saturated, superheated, or supersaturated form. ### Claim 3 (depends on 1) The process of claim 1, wherein said extraction solution comprises hot water. ### Claim 4 (depends on 1) The process of claim 1, wherein said extraction solution contains from about 0.01 wt % to about 10 wt % acetic acid. ### Claim 5 (depends on 1) The process of claim 1, wherein said soluble ash includes one or more species selected from the group consisting of chlorine, chlorides, silica, silicates, metals, and combinations or derivatives thereof ### Claim 6 (depends on 1) The process of claim 1, said process further comprising, between steps (d) and (e), concentrating said extract liquor in an intermediate evaporation stage at a pH of 4.8 or less to release vaporized acetic acid, and recycling at least a portion of said vaporized acetic acid derived from said intermediate evaporation stage back to said extraction solution. ### Claim 7 (depends on 1) The process of claim 1, wherein said effective hydrolysis conditions in step (e) include hydrolysis in the presence of heat and acetic acid. ### Claim 8 (depends on 1) The process of claim 1, wherein said at least one evaporation stage in step (f) is controlled at a pH selected from about 3 to 4.8. ### Claim 9 (depends on 1) The process of claim 1, wherein said low-ash biomass contains about the same moisture content as contained in said cellulosic biomass. ### Claim 10 (depends on 1) The process of any claim 1, wherein said low-ash biomass has higher energy density than said cellulosic biomass. ### Claim 11 (depends on 1) The process of claim 1, wherein said low-ash biomass has lower inorganic emissions potential compared to said cellulosic biomass. ### Claim 12 (depends on 1) The process of claim 1, said process further comprising combusting said low-ash biomass, to produce power. ### Claim 13 (depends on 12) The process of claim 12, said process further comprising co-combusting lignin with said low-ash biomass, to produce power. ### Claim 14 (depends on 1) The process of claim 1, said process comprising pelletizing said dewatered solids, optionally with lignin as a binder. ### Claim 15 (depends on 1) The process of claim 1, said process comprising pelletizing said low-ash biomass, optionally with lignin as a binder. ### Claim 16 (depends on 1) The process of claim 1, said process further comprising a step of fermenting said hemicellulosic sugars to a fermentation product. ### Claim 17 (depends on 16) The process of claim 16, said process further comprising distilling said fermentation product to produce a purified fermentation product and a distillation bottoms stream; introducing said distillation bottoms stream to a bottoms evaporation stage, to produce residual solids; and then co-combusting at least a portion of said residual solids with said low-ash biomass, to produce power. ### Claim 18 (depends on 16) The process of claim 16, said process further comprising distilling said fermentation product to produce a purified fermentation product and a distillation bottoms stream; introducing said distillation bottoms stream to a bottoms evaporation stage, to produce residual solids; and then recovering said residual solids as a fermentation co-product in solid, liquid, or slurry form for use as a fertilizer or fertilizer component. ### Claim 19 A process for producing power from cellulosic biomass, said process comprising: (a) providing a cellulosic biomass feedstock; (b) providing an extraction solution comprising steam and/or hot water, and starting acetic acid; (c) treating said feedstock with said extraction solution under effective extraction conditions to produce an extract liquor containing soluble ash, hemicellulosic oligomers, inorganic components, acetic acid, dissolved lignin, and cellulose-rich solids; (d) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce dewatered solids containing cellulose and lignin; (e) hydrolyzing said hemicellulosic oligomers contained in said extract liquor, under effective hydrolysis conditions, to produce hemicellulosic sugars, wherein said effective hydrolysis conditions release acetyl groups to generate additional acetic acid; (f) removing a vapor stream comprising water and vaporized acetic acid from said extract liquor in at least one evaporation stage at a pH of 4.8 or less, to produce a concentrated extract liquor comprising said hemicellulosic sugars; (g) recycling at least a portion of said vapor stream from step (f), or a condensed form thereof, back to step (b) to provide at least some of said starting acetic acid for said extraction solution and to provide heat for step (c); and (h) combusting said dewatered solids, or a dried form thereof, to produce power. ### Claim 20 A process for producing biomass pellets from cellulosic biomass, said process comprising: (a) providing a feedstock comprising cellulosic biomass; (b) providing an extraction solution comprising steam and/or hot water, and starting acetic acid; (c) treating said feedstock with said extraction solution under effective extraction conditions to produce an extract liquor containing soluble ash, hemicellulosic oligomers, acetic acid, dissolved lignin, and cellulose-rich solids; (d) separating at least a portion of said cellulose-rich solids from said extract liquor, to produce dewatered solids containing cellulose and lignin; (e) hydrolyzing said hemicellulosic oligomers contained in said extract liquor, under effective hydrolysis conditions, to produce hemicellulosic sugars, wherein said effective hydrolysis conditions release acetyl groups to generate additional acetic acid; (f) removing a vapor stream comprising water and vaporized acetic acid from said extract liquor in at least one evaporation stage at a pH of 4.8 or less, to produce a concentrated extract liquor comprising said hemicellulosic sugars; (g) recycling at least a portion of said vapor stream from step (f), or a condensed form thereof, back to step (b) to provide at least some of said starting acetic acid for said extraction solution and to provide heat for step (c); and (h) pelletizing said dewatered solids, or a dried form thereof, to produce biomass pellets.