# US 8,765,428 B2 · Flow-through biological conversion of lignocellulosic biomass > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,765,428 B2 - Document ID: US8765428B2 - Status: Granted - Kind: B2 - Application number: 13/054,750 - Filed: 2009-07-17 - Published: 2012-02-02 - Granted: 2014-07-01 - Earliest claimed: 2008-07-18 - Assignees: Mascoma Corporation - Applicants: Christopher D. Herring; Chaogang Liu; John Bardsley - Inventors: Christopher D. Herring; Chaogang Liu; John Bardsley - Web page: https://patentgrep.com/patent/US8765428B2 ## CPC - C12P 7/10: substrate containing cellulosic material - C08B 37/0003: {General processes for their isolation or fractionation, e.g. purification or extraction from biomass} - C08B 37/0057: {beta-D-Xylans, i.e. xylosaccharide, e.g. arabinoxylan, arabinofuronan, pentosans; (beta-1,3)(beta-1,4)-D-Xylans, e.g. rhodymenans; Hemicellulose; Derivatives thereof} - C08H 8/00: Macromolecular compounds derived from lignocellulosic materials {(pretreatment thereof B27N)} - C12M 21/12: {for producing fuels or solvents (C12M21/04 takes precedence; liquid carbonaceous fuels C10L1/00, solid fuels C10L5/00)} - C12M 27/02: {Stirrer or mobile mixing elements} - C12M 29/04: {Filters; Permeable or porous membranes or plates, e.g. dialysis} - C12M 45/09: {by enzymatic treatment} - 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) - D21C 3/22: Other features of pulping processes - Y02E 50/10: Biofuels, e.g. bio-diesel - 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)} - 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) - C12M: APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; {APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS} - 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) - D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present invention is directed to a process for biologically converting carbohydrates from lignocellulosic biomass comprising the steps of: suspending lignocellulosic biomass in a flow-through reactor, passing a reaction solution into the reactor, wherein the solution is absorbed into the biomass substrate and at least a portion of the solution migrates through said biomass substrate to a liquid reservoir, recirculating the reaction solution in the liquid reservoir at least once to be absorbed into and migrate through the biomass substrate again. The biological converting of the may involve hydrolyzing cellulose, hemicellulose, or a combination thereof to form oligosaccharides, monomelic sugars, or a combination thereof; fermenting oligosaccharides, monomelic sugars, or a combination thereof to produce ethanol, or a combination thereof. The process can further comprise removing the reaction solution and processing the solution to separate the ethanol produced from non-fermented solids. ## Claims ### Claim 1 A process for biologically converting carbohydrates from lignocellulosic biomass, comprising the steps of: suspending lignocellulosic biomass in a flow-through reactor, wherein said reactor comprises: a reactor vessel having a fluid inlet and a fluid outlet; a reservoir tank having a fluid inlet and a fluid outlet, wherein said fluid outlet of said reservoir tank is fluidly connected to said fluid inlet of said reactor vessel; and a fluid passageway, wherein one end of said passageway is connected to said fluid outlet of said reactor vessel and another end of said passageway is connected to said fluid inlet of said reservoir tank; passing a reaction solution into said reactor, wherein said reaction solution is absorbed into said biomass and at least a portion of said reaction solution migrates through said biomass substrate to a liquid reservoir in said reactor vessel; and recirculating said reaction solution in said liquid reservoir at least once, wherein said reaction solution flows from said fluid outlet of said reactor vessel through said passageway to said reservoir tank and then into said fluid inlet of said reactor vessel; whereby a portion of carbohydrates in said lignocellulosic biomass are biologically converted, wherein said biological conversion comprises fermenting oligosaccharides, monomeric sugars, or a combination thereof to produce a fermentation product, and wherein said recirculation of said solution is driven by a build-up of fermentation gases in said flow-through reactor. ### Claim 2 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said lignocellulosic biomass is pretreated before suspending in said reactor. ### Claim 3 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said migration of said reaction solution is driven by gravity. ### Claim 4 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said migration of said reaction solution is driven by pressure. ### Claim 5 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein a portion of said carbohydrates is biologically converted by: (a) hydrolyzing cellulose, hemicellulose, or a combination thereof to form oligosaccharides, monomeric sugars, or a combination thereof; (b) fermenting oligosaccharides, monomeric sugars, or a combination thereof to produce ethanol; or (c) a combination thereof. ### Claim 6 (depends on 5) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 5, wherein a portion of said carbohydrates is biologically converted by fermenting oligosaccharides, monomeric sugars, or a combination thereof to produce ethanol and further comprising: removing said reaction solution in said liquid reservoir; and processing said solution to separate ethanol and non-fermented solids in said reaction solution. ### Claim 7 (depends on 6) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 6, wherein the processing said solution to separate ethanol and non-fermented solids is selected from the group consisting of beer column tray separation, paddle dryer apparatus separation, twin screw conveyer separation, rotary valve separation, butterfly valve separation, distillation, centrifuging and combinations thereof. ### Claim 8 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said biomass substrate is at least partially submerged in said reaction solution in said liquid reservoir. ### Claim 9 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said lignocellulosic biomass is selected from the group consisting of grass, switch grass, cord grass, rye grass, reed canary grass, miscanthus, sugar-processing residues, sugarcane bagasse, agricultural wastes, rice straw, rice hulls, barley straw, corn cobs, cereal straw, wheat straw, canola straw, oat straw, oat hulls, beet pulp, palm residue, corn fiber, stover, soybean stover, corn stover, forestry wastes, recycled wood pulp fiber, paper sludge, sawdust, hardwood, softwood, and combinations thereof. ### Claim 10 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein the reaction solution includes fermentation organisms, cellulase enzymes, or a combination thereof. ### Claim 11 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein said reactor vessel comprises: a first perforated screen and a second perforated screen, wherein said biomass is suspended between said first perforated screen and said second perforated screen. ### Claim 12 (depends on 11) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 11, wherein said flow-through reactor further comprises: a pump to facilitate recirculating said reaction solution, wherein said pump is disposed in said fluid passageway. ### Claim 13 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein activated carbon is added to said biomass or said liquid reservoir. ### Claim 14 (depends on 1) The process for biologically converting carbohydrates from lignocellulosic biomass according to claim 1, wherein: said fermentation product is ethanol; said reactor vessel contains a first perforated screen and a second perforated disc; and said reservoir tank contains a one-way check valve. ### Claim 15 A process for producing ethanol from lignocellulosic biomass, comprising the steps of: suspending pretreated lignocellulosic biomass in a flow-through reactor; hydrolyzing said biomass to form monomeric sugars; passing a reaction solution through said biomass; wherein said reaction solution is absorbed into said biomass and at least a portion of said solution migrates through said biomass substrate to a liquid reservoir; recirculating said reaction solution in said liquid reservoir at least once; and fermenting said monomeric sugars to produce ethanol, wherein said recirculation of said solution is driven by a build-up of fermentation gases in said flow-through reactor. ### Claim 16 (depends on 15) The process for producing ethanol according to claim 15, further comprising: removing said reaction solution in said liquid reservoir; and processing to separate ethanol and non-fermented solids in said reaction solution. ### Claim 17 (depends on 15) The process of claim 15, wherein said hydrolyzing comprises enzymatically hydrolyzing cellulose and hemi-cellulose to form monomeric sugars. ### Claim 18 (depends on 15) The process of claim 15, wherein said hydrolyzing comprises chemically hydrolyzing cellulose and hemi-cellulose to form monomeric sugars. ### Claim 19 (depends on 15) The process of claim 15, wherein said fermenting comprises enzymatically fermenting said monomeric sugars to produce ethanol. ### Claim 20 (depends on 15) The process of claim 15, wherein said hydrolyzing and fermenting occur concurrently. ### Claim 21 (depends on 20) The process of claim 20, wherein hydrolyzing and fermenting occur in the presence of activated carbon. ### Claim 22 (depends on 21) The process of claim 21, wherein said activated carbon is added to said liquid reservoir. ### Claim 23 (depends on 21) The process of claim 21, wherein said activated carbon is added to said biomass. ### Claim 24 (depends on 15) The process of claim 15, wherein said flow-through reactor comprises: a reactor vessel having a fluid inlet and a fluid outlet; and a fluid passageway, wherein one end of said passageway is connected to said fluid outlet of said reactor vessel and another end of said passageway is connected to said fluid inlet of said reactor vessel. ### Claim 25 (depends on 15) The process of claim 15, wherein said flow-through reactor comprises: a reactor vessel having a fluid inlet and a fluid outlet; a reservoir tank having a fluid inlet and a fluid outlet, wherein said fluid outlet of said reservoir tank is fluidly connected to said fluid inlet of said reactor vessel; and a fluid passageway, wherein one end of said passageway is connected to said fluid outlet of said reactor vessel and another end of said passageway is connected to said fluid inlet of said reservoir tank. ### Claim 26 (depends on 15) The process of claim 15, wherein said migration of said reaction solution is driven by gravity. ### Claim 27 (depends on 15) The process of claim 15, wherein said migration of said reaction solution is driven by pressure.