# US 2019/0169155 A1 · Single Step Lactide Production Process with Hydrolysis of Oligomers and Catalyst by Recovered Water > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169155 A1 - Document ID: US20190169155A1 - Status: Published application - Kind: A1 - Application number: 16/309,963 - Filed: 2017-06-20 - Published: 2019-06-06 - Earliest claimed: 2016-06-20 - Assignees: Total Research & Technology Feluy - Applicants: Total Research & Technology Feluy - Inventors: Mahdi Yazdanpanah; Jamal Chaouki; Pieter Van Wouwe; Bert Sels - Web page: https://patentgrep.com/patent/US20190169155A1 ## CPC - C07D 319/12: not condensed with other rings - B01J 19/1862: {placed in series} - B01J 2219/00031: Semi-batch or fed-batch processes - B01J 2219/0004: Processes in series - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract The present invention relates to a process for synthesizing lactide comprising the steps of: providing one or more components to at least one reactor, the one or more components comprising lactic acid; converting at least part of the lactic acid into lactide and water and into lactic acid oligomers; recovering at least part of the lactide; recovering at least part of the water and at least part of the lactic acid oligomers; adding a feed, optionally comprising lactic acid oligomers, and optionally comprising water, to the recovered water and the recovered lactic acid oligomers, and mixing the feed with the recovered water and the recovered lactic acid oligomers to form a mixture; converting at least part of the lactic acid oligomers in the mixture into lactic acid and into lactic acid dimer; and removing at least part of the water from the mixture; whereby at least part of the remainder of the mixture is provided as one of the one or more components that are provided to the at least one reactor; and, wherein the step of converting at least part of the lactic acid into lactide and water is performed in one step. ## Claims ### Claim at position 1 -15. (canceled) ### Claim 16 A process for synthesizing lactide, comprising the steps of: providing one or more components to at least one reactor, the one or more components comprising lactic acid; converting at least part of the lactic acid into lactide and water and into lactic acid oligomers; recovering at least part of the lactide; recovering at least part of the water and at least part of the lactic acid oligomers; adding a feed, optionally comprising lactic acid oligomers, and optionally comprising water, to the recovered water and the recovered lactic acid oligomers, and mixing the feed with the recovered water and the recovered lactic acid oligomers to form a mixture; converting at least part of the lactic acid oligomers in the mixture into lactic acid and into lactic acid dimer; and removing at least part of the water from the mixture; whereby at least part of the remainder of the mixture is provided as one of the one or more components that are provided to the at least one reactor; and, wherein the step of converting at least part of the lactic acid into lactide and water is performed in one step. ### Claim 17 (depends on 16) The process according to claim 16, wherein the process is an industrial process for synthesizing lactide. ### Claim 18 (depends on 16) The process according to claim 16, wherein the one or more components provided to the at least one reactor comprises at least 1% by weight of lactic acid and at most 95% by weight of lactic acid, with % by weight based on the total weight of the one or more components. ### Claim 19 (depends on 16) The process according to claim 16, wherein the step of converting at least part of the lactic acid oligomers in the mixture into lactic acid and into lactic acid dimer is performed through hydrolysis by the recovered water and/or through hydrolysis by water present in the feed. ### Claim 20 (depends on 16) The process according to claim 16, wherein the one or more components comprise at least one catalyst system, and wherein the process comprises the steps of: providing at least one catalyst system to the at least one reactor; recovering at least part of the at least one catalyst system; and regenerating at least part of the recovered catalyst system. ### Claim 21 (depends on 20) The process according to claim 20, wherein the step of regenerating at least part of the recovered catalyst system is performed through hydrolysis by the recovered water and/or through hydrolysis by water present in the feed. ### Claim 22 (depends on 20) The process according to claim 20, wherein the at least one catalyst system is regenerated in-line with the at least one reactor. ### Claim 23 (depends on 20) The process according to claim 20, wherein the at least one catalyst system comprises an acidic zeolite. ### Claim 24 (depends on 16) The process according to claim 16, wherein the step of removing at least part of the water from the mixture is performed with a membrane. ### Claim 25 (depends on 16) The process according to claim 16, wherein the feed comprises lactic acid oligomers. ### Claim 26 (depends on 16) The process according to claim 16, wherein the feed comprises at least 1% by weight lactic acid oligomers and at most 20% by weight lactic acid oligomers with % by weight compared to the total weight of lactic acid, lactic acid dimer, and lactic acid oligomers combined. ### Claim 27 (depends on 16) The process according to claim 16, wherein the step of converting at least part of the lactic acid oligomers in the mixture into lactic acid and into lactic acid dimer, and optionally the step of regenerating at least part of the recovered catalyst system, is performed in one or more recycling pipes. ### Claim 28 (depends on 16) The process according to claim 16, comprising the steps of: adding thermal energy to at least one solvent; providing one or more components to at least one reactor, the one or more components comprising lactic acid and the at least one solvent; converting at least part of the lactic acid into lactide and water; and recovering at least part of the lactide; wherein the step of adding thermal energy to the at least one solvent is performed prior to the step of adding the at least one solvent to the at least one reactor; and wherein the at least one solvent is provided in the at least one reactor independently from the lactic acid by a separate entry into the at least one reactor. ### Claim 29 (depends on 16) The process according to claim 16, comprising the steps of: adding thermal energy to at least one of one or more components; providing the one or more components to at least one reactor, the one or more components comprising lactic acid; converting at least part of the lactic acid into lactide and water; recovering at least part of the lactide; recovering at least part of the thermal energy; and adding the recovered thermal energy to at least one of the one or more components. ### Claim 30 (depends on 16) The process according to claim 16, comprising the steps of: providing one or more components to at least one reactor, the one or more components comprising lactic acid; converting at least part of the lactic acid into lactide and water; recovering at least part of the lactide; and recovering at least part of the water; wherein the step of recovering at least part of the water comprises a decantation step, with the proviso that the step of recovering at least part of the water does not comprise an azeotropic distillation step.