# US 5,350,862 A · Process for the preparation of ethylene glycol carbonate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,862 A - Document ID: US5350862A - Status: Granted - Kind: A - Application number: 07/984,789 - Filed: 1992-12-03 - Granted: 1994-09-27 - Earliest claimed: 1991-12-13 - Assignees: Bayer Aktiengesellschaft - Inventors: Paul Wagner; Hans-Josef Buysch; Alexander Klausener; Franz-Josef Mais; Christine Mendoza-Frohn - Web page: https://patentgrep.com/patent/US5350862A ## CPC - C07D 317/38: Ethylene carbonate - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) ## Abstract A process is described for the catalytic preparation of ethylene glycol carbonate by reaction of ethylene oxide and CO.sub.2 in ethylene glycol carbonate as the reaction medium at elevated temperature and at elevated pressure with work-up by distillation to separate the resulting ethylene glycol carbonate from the catalyst. The process is carried out continuously under adiabatic temperature conditions. Per unit of time, ethylene glycol carbonate as reaction medium runs into the reactor in a amount 10 to 120 times that of ethylene glycol carbonate formed per unit of time. A CO.sub.2 excess over the other reaction partner ethylene oxide is maintained at all sites of the reactor. 80 to 98% by weight of the reaction mixture flowing out is returned to the inlet of the reactor, while the remainder is worked up by distillation to give ethylene glycol carbonate. The sensible heat produced in the reaction product as a result of the adiabatic temperature conditions, is used for the work-up. ## Claims ### Claim 1 A process for the catalytic preparation of ethylene glycol carbonate by reaction of ethylene oxide and carbon dioxide in ethylene glycol carbonate as the reaction medium at elevated temperature and elevated pressure with work-up to separate the resulting ethylene glycol carbonate from the catalyst, wherein a) the process is carried out continuously and adiabatically at a pressure of 2 to 200 bar and within a temperature range of 110.degree. to 200.degree. C., with an adiabatic temperature increase of 5 to 80.degree. C, the inlet temperature being selected in such a manner that the adiabatic temperature increase remains within the temperature range mentioned, b) the ethylene glycol carbonate running into the reactor per unit of time as reaction medium is 10 to 120 times the ethylene glycol carbonate formed in this unit of time, c) 1.01 to 1.3 mol of carbon dioxide are used per mole of ethylene oxide and a carbon dioxide excess is maintained at all sites of the reactor. d) 80 to 98% by weight of the total reaction mixture is returned to the inlet of the reactor and the remainder is worked up to give ethylene glycol carbonate. ### Claim 2 (depends on 1) The process of claim 1, which is carried out at a pressure of 5-80 bar. ### Claim 3 (depends on 2) The process of claim 2, which is carried out at a pressure of 8-60 bar. ### Claim 4 (depends on 1) The process of claim 1, which is carried out within a temperature range of 110.degree. to 190.degree. C. ### Claim 5 (depends on 4) The process of claim 4, which is carried out within a temperature range of 110.degree.-180.degree. C. ### Claim 6 (depends on 1) The process of claim 1, wherein a turbulent flow is maintained in the reactor. ### Claim 7 (depends on 6) The process of claim 6, wherein the reactor contains perforated trays, pipe distributors, two-liquid nozzles, jet nozzles, closed gas distributors, impingement aerator elements, mixer elements or a combination of a plurality thereof. ### Claim 8 (depends on 1) The process of claim 1, wherein, to produce the carbon dioxide excess, at least some of the carbon dioxide is fed into the ethylene glycol carbonate, acting as reaction medium, prior to the injection of the ethylene oxide. ### Claim 9 (depends on 8) The process of claim 8, wherein the carbon dioxide fed prior to the injection of the ethylene oxide is added to the ethylene glycol carbonate prior to entry into the reactor. ### Claim 10 (depends on 8) The process of claim 8, wherein ethylene oxide is fed into the reactor alone or as a mixture with or without remaining carbon dioxide at at least two sequential sites in such a manner that a carbon dioxide excess always exists. ### Claim 11 (depends on 10) The process of claim 10, wherein the intended excess of carbon dioxide is added to the ethylene glycol carbonate prior to its entry into the reactor and the remaining carbon dioxide is fed as an equimolar ethylene oxide/carbon dioxide mixture into the reactor. ### Claim 12 (depends on 1) The process of claim 1 wherein said workup is by distillation and the sensible heat produced in the reaction mixture as a result of the adiabatic-temperature increase is utilized in said distillation. ### Claim 13 (depends on 12) The process of claim 12, wherein the sensible heat achieved of the reaction mixture, is additionally used to generate heating steam. ### Claim 14 (depends on 13) The process of claim 13, wherein in the recovery of the sensible heat, a cooling of the reaction mixture by 5.degree. to 80.degree. C. occurs. ### Claim 15 (depends on 14) The process of claim 14, wherein a cooling of the reaction mixture by 10.degree. to 50.degree. C. occurs. ### Claim 16 (depends on 15) The process of claim 15, wherein a cooling of the reaction mixture by 10.degree. to 40.degree. C. occurs. ### Claim 17 (depends on 13) The process of claim 13, wherein the work-up by distillation to give ethylene glycol carbonate with utilisation or the recovered sensible heat is carried out at 2 to 100 mbar. ### Claim 18 (depends on 17) The process of claim 17, wherein the work-up is carried out at 8 to 90 mbar. ### Claim 19 (depends on 18) The process of claim 18, wherein the work-up is carried out at 10 to 80 mbar.