# US 4,399,000 A · Process for producing absolute alcohol by solvent extraction and vacuum distillation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,000 A - Document ID: US4399000A - Status: Granted - Kind: A - Application number: 06/309,258 - Filed: 1981-10-07 - Granted: 1983-08-16 - Earliest claimed: 1981-10-07 - Assignees: Georgia Tech Research Institute - Inventors: Daniel W. Tedder - Web page: https://patentgrep.com/patent/US4399000A ## CPC - C07C 29/86: by liquid-liquid treatment - Y10S 203/04: Heat pump - Y10S 203/14: Ejector-eductor - Y10S 435/813: Continuous fermentation - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Alcohol substantially free of water is produced by a process comprising extracting an aqueous alcohol solution with an organic solvent system containing an extractant for said alcohol thereby forming an organic solvent-alcohol phase and an aqueous phase, and vacuum distilling said organic solvent-alcohol phase thereby obtaining the product alcohol substantially free of water. ## Claims ### Claim 1 A method for producing alcohol substantially free of water, comprising: extracting an aqueous alcohol solution with an organic solvent system comprising an organic solvent and an extractant for said alcohol selected from the group consisting of a symmetric or asymmetric alkyl or aryl phosphate, a phosphonate, a phosphine oxide, a sulfoxide, a sulfone, an amine oxide or a quarternary ammonium or phosphonium salt in a ratio of 1 to 10 parts by weight solvent to one part by weight extractant, thereby forming an organic solvent-alcohol phase and an aqueous phase; and vacuum distilling said organic solvent-alcohol phase thereby obtaining the product alcohol substantially free of water. ### Claim 2 (depends on 1) The method of claim 1, wherein said aqueous alcohol solution is obtained by fermenting a suitable biomass material and then clarifying the fermented aqueous medium. ### Claim 3 (depends on 1) The method of claim 1, wherein said extractant in said organic solvent system is a symmetric or asymmetric alkyl or aryl phosphate, phosphonate, phosphine oxide, sulfoxide, sulfone, amine oxide, quaternary ammonium or phosphonium salt or a high boiling alcohol. ### Claim 4 (depends on 3) The method of claim 3, wherein said extractant is a member selected from the group consisting of trineopentylphosphate, dibutyl butyl phosphonate, di-2-ethylhexyl phosphate, 2-ethylhexylphosphonate, cyclohexyl di-t-butylphosphate, tri-2,6-dimethylphenyl phosphate, triphenylphosphine oxide, dineopentyl sulfoxide, dineopentylsulfone, tri-isopropylamine oxide and tetra-n-butylammonium-2,6-di-t-butylbenzoate. ### Claim 5 (depends on 1) The method of claim 1, wherein, in the said extraction step, from 0.5 to 10 parts by weight of said organic solvent system are contacted with one part by weight of said aqueous alcohol solution. ### Claim 6 (depends on 1) The method of claim 1, wherein said extraction is conducted at a temperature ranging from 15.degree. to 98.degree. C. ### Claim 7 (depends on 1) The method of claim 1, wherein the solvent component of said organic solvent system is an aliphatic hydrocarbon, a liquid aromatic hydrocarbon, a halogenated hydrocarbon, or mixtures thereof. ### Claim 8 (depends on 7) The method of claim 7, wherein said mixed solvent is a mixture of gasoline and kerosene. ### Claim 9 (depends on 1) The method of claim 1, wherein said solvent-alcohol mixture is distilled at a reduced pressure ranging from 1 to 500 mm Hg. ### Claim 10 (depends on 1) The method of claim 1, which further comprises: condensing the alcohol vapors obtained by vacuum distilling said solvent-alcohol phase in a heat exchange device; and recycling a portion of said condensed alcohol substantially free of water to said extraction step to enhance the drying of alcohol in said solvent-alcohol phase. ### Claim 11 (depends on 10) The method of claim 10, wherein from 1 to 75 parts by wt. alcohol are recycled per 10 part by wt. of solvent-alcohol phase. ### Claim 12 (depends on 10) The method of claim 10, wherein heat in said alcohol product substantially free of water is recycled in the process by: (a) absorbing heat in said heat exchange device by a low pressure thermodynamic liquid; (b) compressing the low pressure vapor obtained to a high pressure vapor; and (c) transferring the heat in said compressed vapor to said organic solvent-alcohol phase being vacuum distilled. ### Claim 13 A method for producing alcohol substantially free of water, comprising: extracting an aqueous alcohol solution with an organic solvent system comprising an organic solvent and an extractant for said alcohol selected from the group consisting of a symmetric or asymmetric alkyl or aryl phosphate, a phosphonate, a phosphine oxide, a sulfoxide, a sulfone, an amine oxide or a quarternary ammonium or phosphonium salt in a ratio of 1 to 10 parts by weight solvent to one part by weight extractant, thereby forming an organic solvent-alcohol phase and an aqueous phase; heating said organic solvent-alcohol phase; vacuum distilling said heated organic solvent-alcohol phase thereby obtaining a substantially water free alcohol vapor; condensing and withdrawing heat from said alcohol vapor by a low pressure thermodynamic fluid; and transferring the heat in said low pressure thermodynamic fluid to the organic solvent-alcohol phase being sent to said vacuum distillation unit by means of a heat pump.