# US 2021/0171484 A1 · Method and System for Producing Epoxyalkane > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0171484 A1 - Document ID: US20210171484A1 - Status: Published application - Kind: A1 - Application number: 16/768,663 - Filed: 2018-11-30 - Published: 2021-06-10 - Earliest claimed: 2017-11-30 - Assignees: China Petroleum & Chemical Corporation; Shanghai Research Institute of Petrochemical Technology, Sinopec - Applicants: China Petroleum & Chemical Corporation; Shanghai Research Institute of Petrochemical Technology Sinopec - Inventors: Song HU; Shuai HU; Weisheng YANG - Web page: https://patentgrep.com/patent/US20210171484A1 ## CPC - C07D 301/32: Separation; Purification - B01D 3/322: {Reboiler specifications} - B01D 3/324: {Tray constructions} - B01D 3/40: Extractive distillation - C07D 303/04: containing only hydrogen and carbon atoms in addition to the ring oxygen atoms - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A method for producing an epoxyalkane includes the step of separating a stream containing an epoxyalkane and an extracting agent in a separation column having a column kettle reboiler. A part of a stream in the column kettle of the separation column enters an extracting agent purifier and is treated to obtain a gas phase light fraction that returns to the separation column and a liquid phase heavy fraction that is subjected to a post-treatment. The method can be used in the industrial production of an epoxyalkane. ## Claims ### Claim at position 1 1-34. (canceled) ### Claim 35 A method for producing an epoxyalkane, the method comprises the following steps: 1) distilling the stream containing epoxyalkane and extractant in a separation column, obtaining the stream mainly containing epoxyalkane from the column top, and obtaining the stream mainly containing extractant from the column kettle; 2) dividing the stream mainly containing extractant obtained from the column kettle into at least three streams, wherein the first stream is heated by the column kettle reboiler and returned to the separation column from the column kettle; the second stream is used as the circulating extractant; the third stream is delivered to an extractant purifier for carrying out purification treatment to remove liquid phase heavy component whose boiling point is higher than that of the extractant, and obtain the vapor phase or vapor-liquid mixture treated as light component which is mainly extractant; 3) returning the vapor phase or vapor-liquid mixture treated as the light component which is mainly extractant to the separation column. ### Claim 36 (depends on 35) The method according to claim 35, wherein the third stream accounts for 2-20% by weight of the total amount of the stream which is obtained from the column kettle of the separation column and mainly consisting of extractant. ### Claim 37 (depends on 35) The method according to claim 35, wherein the content of epoxyalkane in the stream which is obtained from the column top and mainly consisting of epoxyalkane is not less than 99.95% by weight, and the content of extractant is not higher than 0.05% by weight; the content of extractant in the stream which is obtained from the column kettle and mainly consisting of extractant is not less than 99% by weight, and the content of epoxyalkane is not higher than 1% by weight. ### Claim 38 (depends on 35) The method according to claim 35, wherein the extractant purifier is a distillation column or a reboiler. ### Claim 39 (depends on 38) The method according to claim 38, wherein the extractant purifier is a reboiler. ### Claim 40 (depends on 39) The method according to claim 39, wherein the reboiler is a kettle-type reboiler. ### Claim 41 (depends on 39) The method according to claim 39, wherein the reboiler is located underneath the feed port of the separation column. ### Claim 42 (depends on 39) The method according to claim 39, wherein the ratio of the heat transfer area of the column kettle reboiler to that of the extractant purifier of the separation column is within a range of (2-5):1. ### Claim 43 (depends on 39) The method according to claim 39, wherein the temperature difference of the first stream entering the column kettle reboiler and the third stream entering the extractant purifier is ≤5° C. ### Claim 44 (depends on 39) The method according to claim 39, wherein the temperature difference of the first stream entering the column kettle reboiler and the third stream entering the extractant purifier is ≤3° C. ### Claim 45 (depends on 35) The method according to claim 35, wherein the operating conditions of the separation column include: the temperature of the vapor phase at the column top is within a range of 60-130° C., the temperature at the column top is 30-80° C., the pressure is 0.04-0.40 MPaG, and the number of theoretical plates in separation column is within a range of 15-80. ### Claim 46 (depends on 35) The method according to claim 35, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (2-15):1, based on the mole percent. ### Claim 47 (depends on 35) The method according to claim 35, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (3-10):1, based on the mole percent. ### Claim 48 (depends on 35) The method according to claim 35, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (5-7):1, based on the mole percent. ### Claim 49 (depends on 35) The method according to claim 35, wherein the column kettle reboiler is any one of the group consisting of a thermosyphon reboiler, a kettle-type reboiler and a forced circulation type reboiler. ### Claim 50 (depends on 35) The method according to claim 35, wherein the epoxyalkane is propylene oxide, butylene oxide or isomers of butylene oxide. ### Claim 51 (depends on 35) The method according to claim 35, wherein the epoxyalkane is butylene oxide. ### Claim 52 (depends on 35) The method according to claim 35, wherein the epoxyalkane is 1,2-butylene oxide. ### Claim 53 A method for producing an epoxyalkane, the method comprises: 1) sending the crude product stream containing epoxyalkane and the extractant stream to an extractive rectification column for performing extractive distillation, obtaining a stream including epoxyalkane and extractant from the column kettle; 2) subjecting the stream including epoxyalkane and extractant to rectification in the separation column, obtaining the stream mainly containing epoxyalkane from the column top, and obtaining the stream mainly containing extractant from the column kettle; 3) dividing the stream mainly containing extractant from the column kettle into at least three streams, wherein the first stream is heated by the column kettle reboiler and returned to the separation column from the column kettle; the second stream is used as the circulating extractant; the third stream is delivered to an extractant purifier for carrying out purification treatment to remove liquid phase heavy component whose boiling point is higher than that of the extractant, and obtaining the vapor phase or vapor-liquid mixture treated as light component which is mainly extractant; 4) returning the vapor phase or vapor-liquid mixture treated as the light component which is mainly extractant to the separation column. ### Claim 54 (depends on 53) The method according to claim 53, wherein the third stream accounts for 2-20% by weight of the total amount of the stream which is obtained from the column kettle of the separation column and mainly consisting of extractant. ### Claim 55 (depends on 54) The method according to claim 54, wherein the content of epoxyalkane in the stream which is obtained from the column top and mainly consisting of epoxyalkane is not less than 99.95% by weight, and the content of extractant is not higher than 0.05% by weight; the content of extractant in the stream which is obtained from the column kettle and mainly consisting of extractant is not less than 99% by weight, and the content of epoxyalkane is not higher than 1% by weight. ### Claim 56 (depends on 53) The method according to claim 53, wherein the extractant purifier is a distillation column or a reboiler. ### Claim 57 (depends on 56) The method according to claim 56, wherein the extractant purifier is a reboiler. ### Claim 58 (depends on 57) The method according to claim 57, wherein the reboiler is a kettle-type reboiler. ### Claim 59 (depends on 57) The method according to claim 57, wherein the reboiler is located at the middle part or bottom of the separation column. ### Claim 60 (depends on 57) The method according to claim 57, wherein the ratio of the heat transfer area of the column kettle reboiler to that of the extractant purifier of the separation column is within a range of (2-5):1. ### Claim 61 (depends on 53) The method according to claim 53, wherein the temperature difference of the first stream entering the column kettle reboiler and the third stream entering the extractant purifier is ≤5° C. ### Claim 62 (depends on 53) The method according to claim 53, wherein the temperature difference of the first stream entering the column kettle reboiler and the third stream entering the extractant purifier is ≤3° C. ### Claim 63 (depends on 53) The method according to claim 53, wherein the operating conditions of the separation column include: the temperature of the vapor phase at the column top is within a range of 60-130° C., the temperature at the column top is 30-80° C., the pressure is 0.04-0.40 MPaG, and the number of theoretical plates in separation column is within a range of 15-80. ### Claim 64 (depends on 53) The method according to claim 53, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (2-15):1, based on the mole percent. ### Claim 65 (depends on 53) The method according to claim 53, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (3-10):1, based on the mole percent. ### Claim 66 (depends on 53) The method according to claim 53, wherein the ratio of the extractant to the epoxyalkane in a stream containing epoxyalkane and extractant is (5-7):1, based on the mole percent. ### Claim 67 (depends on 53) The method according to claim 53, wherein the column kettle reboiler is any one of the group consisting of a thermosyphon reboiler, a kettle-type reboiler and a forced circulation type reboiler. ### Claim 68 (depends on 53) The method according to claim 53, wherein the epoxyalkane is propylene oxide, butylene oxide or isomers of butylene oxide. ### Claim 69 (depends on 53) The method according to claim 53, wherein the epoxyalkane is butylene oxide. ### Claim 70 (depends on 53) The method according to claim 53, wherein the epoxyalkane is 1,2-butylene oxide. ### Claim 71 An epoxyalkane production system, the system comprises: 1) a separation column, wherein the column kettle having an outlet being capable of leading the column kettle stream out of the separation column; 2) a column kettle reboiler which is arranged at the lower part of the separation column to reboil part of the kettle reboiler materials of the separation column, and return the reboiled kettle reboiler material to the separation column; 3) an extractant purifier which is arranged underneath the feed position of the separation column for purifying a part of the column kettle material of the separation column to remove heavy components whose boiling point is higher than that of the extractant; obtaining the vapor phase or vapor-liquid mixture treated as light component which is mainly an extractant and returning the light component to the separation column. ### Claim 72 (depends on 71) The system according to claim 71, wherein the extractant purifier is a reboiler. ### Claim 73 (depends on 72) The system according to claim 72, wherein the extractant purifier is a kettle-type reboiler. ### Claim 74 (depends on 72) The system according to claim 72, wherein the ratio of the heat transfer area of the column kettle reboiler to that of the extractant purifier of the separation column is within a range of (2-5):1. ### Claim 75 (depends on 72) The system according to claim 72, wherein the number of theoretical plates in separation column is within a range of 15-80; according to the flow direction of the stream, the feed position of the extractant purifier is located within the zero to 6th plates from the bottom. ### Claim 76 (depends on 72) The system according to claim 72, wherein the number of theoretical plates in separation column is within a range of 15-80; according to the flow direction of the stream, the feed position of the extractant purifier is located within the zero to 4th plates from the bottom. ### Claim 77 (depends on 75) The system of claim 75, wherein the feed position of the extractant purifier is higher than the feed position of the column reboiler with zero to 4 plates. ### Claim 78 (depends on 71) The system according to claim 71, wherein the extractant purifier is in connection with the separation column through a pipeline. ### Claim 79 An epoxyalkane production system, the system comprises: 1) an extractive rectification column for performing extractive distillation of crude product stream containing epoxyalkane; 2) a separation column for separating the column kettle stream from the extractive rectification column, obtaining the stream mainly containing epoxyalkane from the column top, and obtaining the stream mainly containing extractant from the column kettle; 3) a column kettle reboiler which is arranged at the lower part of the separation column to reboil part of the column kettle materials of the separation column, and return the reboiled column kettle material to the separation column; 4) an extractant purifier which is arranged underneath the feed position of the separation column for receiving and purifying a part of the column kettle material of the separation column to remove heavy components whose boiling point is higher than that of the extractant; obtaining the vapor phase or vapor-liquid mixture treated as light component which is mainly an extractant and returning the light component to the separation column. ### Claim 80 (depends on 79) The system according to claim 79, wherein the extractant purifier is a reboiler. ### Claim 81 (depends on 79) The system according to claim 79, wherein the extractant purifier is a kettle-type reboiler. ### Claim 82 (depends on 80) The system according to claim 80, wherein the ratio of the heat transfer area of the column kettle reboiler to that of the extractant purifier of the separation column is within a range of (2-5):1. ### Claim 83 (depends on 80) The system according to claim 80, wherein the number of theoretical plates in separation column is within a range of 15-80; according to the flow direction of the stream, the feed position of the extractant purifier is located within the zero to 6th plates from the bottom. ### Claim 84 (depends on 80) The system according to claim 80, wherein the number of theoretical plates in separation column is within a range of 15-80; according to the flow direction of the stream, the feed position of the extractant purifier is located within the zero to 4th plates from the bottom. ### Claim 85 (depends on 83) The system according to claim 83, wherein the feed position of the extractant purifier is higher than the feed position of the column reboiler with zero to 4 plates. ### Claim 86 (depends on 79) The system according to claim 79, wherein the extractant purifier is in connection with the separation column through a pipeline.