# US 2019/0169149 A1 · A process for preparing propylene oxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0169149 A1 - Document ID: US20190169149A1 - Status: Published application - Kind: A1 - Application number: 16/318,221 - Filed: 2017-07-19 - Published: 2019-06-06 - Earliest claimed: 2016-07-20 - Assignees: BASF SE; Dow Global Technologies LLC - Applicants: BASF SE; Dow Global Technologies LLC - Inventors: Joaquim Henrique TELES; Marvin KRAMP; Christian MUELLER; Nicolai Tonio WOERZ; Bernd METZEN; Tobias KELLER; Dominic RIEDEL; Heiner SCHELLING; Markus WEBER; Daniel URBANCZYK; Andrei-Nicolae PARVULESCU; Ulrike WEGERLE; Ulrich MUELLER; Meinolf WEIDENBACH; Werner J. WITZL; Karsten LUECKE - Web page: https://patentgrep.com/patent/US20190169149A1 ## CPC - C07D 301/32: Separation; Purification - B01D 1/28: with vapour compression - B01D 3/00: Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping ({evaporation in general, e.g. of liquids for gas phase reactions B01B1/005;} gas chromatography B01D15/08; destructive distillation C10B; preparation of alcoholic beverages by distillation C12H6/02) - B01D 3/009: {in combination with chemical reactions} - B01D 3/143: {by two or more of a fractionation, separation or rectification step} - B01D 3/40: Extractive distillation - B01D 5/006: {with evaporation or distillation} - B01J 29/7038: {MWW-type, e.g. MCM-22, ERB-1, ITQ-1, PSH-3 or SSZ-25} - B01J 29/86: Borosilicates; Aluminoborosilicates {(B01J29/005 takes precedence)} - B01J 29/89: Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium {(B01J29/005 takes precedence)} - B01J 35/37: Crush or impact strength - B01J 35/45: Nanoparticles - B01J 35/70: characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) - B01J 35/77: Compounds characterised by their crystallite size - B01J 37/0045: {Drying a slurry, e.g. spray drying} - C07D 301/12: with hydrogen peroxide or inorganic peroxides or peracids - C07D 303/04: containing only hydrogen and carbon atoms in addition to the ring oxygen atoms - B01J 29/085: {containing rare earth elements, titanium, zirconium, hafnium, zinc, cadmium, mercury, gallium, indium, thallium, tin or lead} - B01J 2229/186: not in framework positions - B01J 2229/42: Addition of matrix or binder particles - B01J 2235/05: Nuclear magnetic resonance [NMR] - B01J 2235/10: Infrared [IR] - B01J 2235/15: X-ray diffraction - Y02P 20/10: Process efficiency - Y02P 20/52: using catalysts, e.g. selective catalysts - 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) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract The present invention is related to a process for preparing propylene oxide, comprising (i) providing a stream comprising propene, hydrogen peroxide or a source of hydrogen peroxide, water, and an organic solvent; (ii) passing the liquid feed stream provided in (i) into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propene, propylene oxide, water, and the organic solvent; (iii) removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, water, organic solvent, and propene; (iv) separating propene from the effluent stream by distillation, comprising (iv.1) subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous top stream S0 enriched in propene compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S01 enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions; (iv.2) returning a condensed portion of the stream S0 to an upper part of the distillation unit. ## Claims ### Claim 1 A process for preparing propylene oxide, the process comprising: (i) providing a liquid feed stream comprising propene, hydrogen peroxide or a source of hydrogen peroxide, water, and an organic solvent; (ii) passing the liquid feed stream into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, thereby obtaining a reaction mixture comprising propene, propylene oxide, water, and the organic solvent; (iii) removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, water, organic solvent, and propene; and (iv) separating propene from the effluent stream by distillation, comprising (iv.1) subjecting the effluent stream to distillation conditions in a distillation unit, thereby obtaining a gaseous top stream S0 enriched in propene compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S01 enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions; and (iv.2) returning a condensed portion of the gaseous top stream S0 to an upper part of the distillation unit. ### Claim 2 (depends on 1) The process of claim 1, wherein the liquid feed stream further comprises propane; the reaction mixture further comprises propane; the effluent stream further comprises propane; the separating is separating the propene and propane; and the gaseous top stream S0 is enriched in the propene and propane. ### Claim 3 (depends on 1) The process of claim 1, wherein the distillation unit employed is at least one distillation tower wherein the distillation tower has from 3 to 50 theoretical trays. ### Claim 4 (depends on 1) The process of claim 1, wherein a rectifying section of the distillation unit consists of from 50 to 75% of theoretical trays and a stripping section of the distillation unit consists of from 25 to 50% of theoretical trays. ### Claim 5 (depends on 1) The process of claim 1, wherein the distillation unit is operated at a top pressure of from 0.5 to 2.8 bar. ### Claim 6 (depends on 1) The process of claim 1, wherein the distillation unit is operated at a top temperature of from −70 to −30° C. ### Claim 7 (depends on 1) The process of claim 1, wherein the gaseous top stream S0 removed from the distillation unit has a pressure of from 0.5 to 2.8 bar and a temperature of from −70 to −30° C. ### Claim 8 (depends on 1) The process of claim 1, wherein the condensed portion of the gaseous top stream S0 is regulated so that an oxygen concentration in an uncondensed portion of the gaseous top stream S0 is less than 10 vol. %. ### Claim 9 (depends on 1) The process of claim 1, further comprising: condensing a portion of the gaseous top stream S0 by compression to a pressure of from 5 to 20 bar, and adjusting the temperature to be of from 20 to 50° C. ### Claim 10 (depends on 1) The process of claim 1, wherein of from 50 to 90 weight-% of the gaseous top stream S0, which form the condensed portion of the gaseous top stream S0, are returned to the upper part of the distillation unit. ### Claim 11 (depends on 1) The process of claim 1, wherein the condensed portion of the gaseous top stream S0 is returned to the upper part of the distillation unit at a top of the distillation unit or within a rectifying section of the distillation unit. ### Claim 12 (depends on 1) The process of claim 1, wherein the condensed portion of the gaseous top stream S0, which is returned to the upper part of the distillation unit in (iv.2), has a temperature of from 20 to 50° C. ### Claim 13 (depends on 1) The process of claim 1, wherein the condensed portion of the the gaseous top stream S0 is heat exchanged with the gaseous top stream S0 prior to the returning to the upper part of the distillation unit. ### Claim 14 (depends on 1) The process of claim 1, wherein a temperature of the condensed portion of the the gaseous top stream S0 is decreased after compression and prior to the returning to the upper part of the distillation unit by 35 to 80 K. ### Claim 15 (depends on 1) The process of claim 1, which is a continuous process.