# US 11,898,309 B2 · Method and a system for obtaining methanol from foul condensate of a pulping process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,309 B2 - Document ID: US11898309B2 - Status: Granted - Kind: B2 - Application number: 16/973,196 - Filed: 2019-06-11 - Published: 2021-03-25 - Granted: 2024-02-13 - Earliest claimed: 2018-06-11 - Assignees: Valmet Corporation - Applicants: Valmet AB - Inventors: Olle Wennberg; David Blomberg Saitton; Thomas Nordlander - Web page: https://patentgrep.com/patent/US11898309B2 ## CPC - D21C 11/00: Regeneration of pulp liquors {or effluent waste waters} - D21C 11/0007: {Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for (volatile compounds obtained by decomposition of spent liquors in order to regenerate them D21C11/125; compounds obtained by fractionating the liquors in order to regenerate them D21C11/0042)} - C07C 29/80: by distillation - C07C 29/88: by treatment giving rise to a chemical modification of at least one compound (chemisorption C07C29/76) - D21C 11/04: of alkali lye - D21C 11/06: Treatment of pulp gases; Recovery of the heat content of the gases; {Treatment of gases arising from various sources in pulp and paper mills; Regeneration of gaseous SO2, e.g. arising from liquors containing sulfur compounds} - C07C 31/04: Methanol - D21C: PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract Embodiments herein relate to a system (200; 300; 400; 500) for obtaining methanol from foul condensate (101) of a pulping process. The system (200; 300; 400; 500) comprises a primary stripper (102) arranged to strip the foul condensate (101) from pollutants, whereby a first methanol-containing condensate is obtained from the polluted stripper off gases (SOGs). The system (200; 300; 400; 500) also comprises a first acidification unit (202) arranged to acidify the first methanol-containing condensate. Further, the system (200; 300; 400; 500) comprises a secondary stripper (204) arranged to strip the acidified first methanol-containing condensate from pollutants to obtain a second methanol-containing condensate, and a distillation column (107) arranged to distil the second methanol-containing condensate from the secondary stripper (204) so as to obtain methanol. Embodiments herein also relate to a method performed in a system (200; 300; 400; 500) for obtaining methanol from foul condensate (101) of a pulping process. ## Claims ### Claim 1 A method performed in a system for obtaining a methanol from a foul condensate of a pulping process, the method comprising: stripping the foul condensate from first pollutants in a primary stripper to produce polluted stripper off gases (SOGs), whereby a first methanol-containing condensate is obtained from the polluted SOGs of the primary stripper by condensing the polluted SOGs of the primary stripper to obtain the first methanol-containing condensate; acidifying the first methanol-containing condensate in a first acidification unit to produce an acidified first methanol-containing condensate where after the acidified first methanol-containing condensate is guided further to a secondary stripper; stripping the acidified first methanol-containing condensate from second pollutants in the secondary stripper in order to remove the second pollutants together with second SOGs and to obtain a second methanol-containing condensate as a remaining condensate in the secondary stripper; and distilling the second methanol-containing condensate from the secondary stripper in a distillation column so as to obtain the methanol and a remaining methanol-containing condensate. ### Claim 2 (depends on 1) The method according to claim 1, further comprising adding sulphite ions to the acidified first methanol-containing condensate. ### Claim 3 (depends on 1) The method according to claim 1, further comprising decanting the first methanol-containing condensate to obtain a decanted first methanol-containing condensate. ### Claim 4 (depends on 3) The method according to claim 3, further comprising acidifying the decanted first methanol-containing condensate. ### Claim 5 (depends on 1) The method according to claim 1, further comprising oxidizing the second methanol-containing condensate. ### Claim 6 (depends on 1) The method according to claim 1, further comprising decanting the second methanol-containing condensate. ### Claim 7 (depends on 1) The method according to claim 1, further comprising acidifying the second methanol-containing condensate. ### Claim 8 (depends on 1) The method according to claim 1, further comprising decanting the remaining methanol-containing condensate after the distilling. ### Claim 9 (depends on 1) The method according to claim 1, further comprising adding an amount of turpentine, or other hydrocarbons, to the first methanol-containing condensate when the amount of turpentine, or other hydrocarbons, in the first methanol-containing condensate is below a determined threshold level. ### Claim 10 (depends on 1) The method according to claim 1, further comprising condensing the second SOGs comprising the second pollutants from the secondary stripper into a polluted condensate; extracting at least part of the second pollutants in the polluted condensate by mixing the polluted condensate with turpentine to obtain a remaining polluted condensate and turpentine mixture; and decanting the remaining polluted condensate and turpentine mixture, so as to separate turpentine from the remaining polluted condensate and turpentine mixture. ### Claim 11 (depends on 1) The method according to claim 1, further comprising cooling the acidified first methanol-containing condensate in an upper equilibrium stage of the secondary stripper.