# US 7,608,191 B2 · Production of a fermentation product > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,191 B2 - Document ID: US7608191B2 - Status: Granted - Kind: B2 - Application number: 10/587,582 - Filed: 2005-01-20 - Published: 2007-07-26 - Granted: 2009-10-27 - Earliest claimed: 2004-02-04 - Assignees: Ciba Specialty Chemicals Water Treatments Ltd. - Inventors: Jonathan Hughes; Rajesh Mistry; Kenneth Charles Symes - Web page: https://patentgrep.com/patent/US7608191B2 ## CPC - C02F 1/56: Macromolecular compounds - C02F 2103/28: from the paper or cellulose industry - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract A process of separating suspended solids from a fermentation liquor by subjecting the liquor to a solids-liquid separation stage, wherein the fermentation liquor is produced in a fermentation process for the production of a fermentation product, and which liquor comprises lignin, wherein the solids-liquid separation stage is assisted by a treatment system, characterized in that the treatment system comprises an anionic polymer, with the proviso that the treatment system and does not include a cationic polymer having an intrinsic viscosity (IV) of at least 4 dl/g. ## Claims ### Claim 1 A process of separating suspended solids from a fermentation liquor by subjecting the liquor to a solids-liquid separation stage, wherein the fermentation liquor is produced in a fermentation process for the production of a fermentation product, which fermentation liquor comprises lignin, wherein the solids-liquid separation stage comprises treating the fermentation liquor with an anionic polymer having an anionic content of at least 50% by weight and having an intrinsic viscosity of at least 4 dl/g (measured in 1 M NaCl at 25° C.) wherein the anionic polymer is formed from anionic monomers selected from the group consisting of (meth) acrylic acid (or salts), maleic acid (or salts), itaconic acid (or salts), fumaric acid (or salts), vinyl sulfonic acid (or salts), allyl sulfonic acid, and 2-acrylamido-2-methyl sulfonic acid (or salts), optionally in the presence of a water-soluble non-ionic acrylamide monomer, flocculating the suspended solids and lignin in the fermentation liquor and subjecting the fermentation liquor to a mechanical dewatering stage selected from at least one of, a centrifuge, a screw press, a filter press, a belt filter press, a horizontal belt filter or a pressure filter to separate the flocculated suspended solids and lignin as cake solids, wherein the cake solids contain mainly lignin, with the proviso that the solids-liquid separation stage does not include a cationic polymer having an intrinsic viscosity (IV) of at least 4 dl/g. ### Claim 2 (depends on 1) A process according to claim 1 in which the fermentation liquor is subjected to a distillation stage wherein the fermentation product is recovered, wherein the liquor is recovered from the distillation stage as a stillage stream and then subjected to the solids-liquid separation stage. ### Claim 3 (depends on 1) A process according to claim 1 in which the fermentation liquor contains the fermentation product wherein the liquor is subjected to the solids-liquid separation stage and then passed to a distillation stage wherein the fermentation product is recovered. ### Claim 4 (depends on 1) A process according to claim 1 in which the solid-liquid separation stage further comprises addition of a cationic polymer that exhibits an intrinsic viscosity below 4 dl/g (measured in 1 M NaCl at 25° C.). ### Claim 5 (depends on 4) A process according to claim 4 in which the cationic polymer exhibits a charge density of at least 3 meq/g. ### Claim 6 (depends on 4) A process according to claim 4 in which the cationic polymer is selected from the group consisting of polyamines, amine/epihalohydrin addition polymers, polymers of dicyandiamide with formaldehyde, polymers of diallyldimethyl ammonium chloride (DADMAC), cationic starch and cationic inulin, polymers of dialkyl amino alkyl (meth)acrylates (or salts) and dialkyl amino alkyl (meth) acrylamides (or salts). ### Claim 7 (depends on 4) A process according to claim 4 in which the anionic polymer and cationic polymer are added sequentially. ### Claim 8 (depends on 4) A process according to claim 4 in which the dose of cationic polymer is at least 50 grams per tonne (based on dry weight of fermentation liquor). ### Claim 9 (depends on 4) A process according to claim 4, wherein the cationic polymer has a molecular weight of below 1,000,000. ### Claim 10 (depends on 1) A process according to claim 1 in which the dose of anionic polymer is at least 50 grams per tonne (based on dry weight of fermentation liquor). ### Claim 11 (depends on 1) A process according to claim 1 in which the solid-liquid separation stage further comprises addition of a siliceous material. ### Claim 12 (depends on 11) A process according to claim 11 in which the siliceous material is selected from the group consisting of silica based particles, silica microgels, colloidal silica, silica sols, silica gels, polysilicates, cationic silica, aluminosilicates, polyaluminosilicates, borosilicates, polyborosilicates, zeolites and swellable clays. ### Claim 13 (depends on 11) A process according to claim 11 in which the siliceous material is an anionic microparticulate material. ### Claim 14 (depends on 11) A process according to claim 11 in which the siliceous material is a bentonite type clay. ### Claim 15 (depends on 11) A process according to claim 11 in which the siliceous material is selected from the group consisting of hectorite, smectites, montmorillonites, nontronites, saponite, sauconite, hormites, attapulgites and sepiolites. ### Claim 16 (depends on 1) A process according to claim 1 in which the treated liquor from which suspended solids have been removed is recycled and used as wash water. ### Claim 17 (depends on 1) A process according to claim 1 wherein the cake solids are subjected to a drying stage to provide a dry solid material and in which the dry solid material is used as a solid fuel. ### Claim 18 (depends on 1) A process according to claim 1 in which the fermentation liquor has not been subjected to a temperature of at least 50° C. ### Claim 19 (depends on 1) A process according to claim 1 in which the fermentation product is selected from the group consisting of ethanol, glycerol, acetone, n-butanol, butanediol, isopropanol, butyric acid, methane, citric acid, fumaric acid, lactic acid, propionic acid, succinic acid, itaconic acid, acetic acid, acetaldehyde and 3-hydroxypropionic acid, glyconic acid, tartaric acid, L-glutamic acid, L-lysine, L-aspartic acid, L-tryptophan, L-arylglycines and salts of any of these acids.