# US 8,785,708 B2 · Process for preparing C2- to C4- olefins from a feed stream comprising oxygenates and steam > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,708 B2 - Document ID: US8785708B2 - Status: Granted - Kind: B2 - Application number: 11/909,629 - Filed: 2006-02-28 - Published: 2010-09-16 - Granted: 2014-07-22 - Earliest claimed: 2005-04-06 - Assignees: Lurgi GmbH - Applicants: Martin Rothaemel; Walter Boll; Gerhard Birke; Harald Koempel; Waldemar Liebner; Hermann Bach - Inventors: Martin Rothaemel; Walter Boll; Gerhard Birke; Harald Koempel; Waldemar Liebner; Hermann Bach - Web page: https://patentgrep.com/patent/US8785708B2 ## CPC - C07C 1/20: starting from organic compounds containing only oxygen atoms as heteroatoms - C07C 2529/70: of types characterised by their specific structure not provided for in groups C07C2529/08 - C07C2529/65 - Y02P 20/52: using catalysts, e.g. selective catalysts - Y02P 30/20: using bio-feedstock - Y02P 30/40: Ethylene production - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract In a process for the preparation of C2- to C4-olefins, a feed stream comprising oxygenates and steam is passed through at least one fixed-bed zone comprising zeolite catalyst, where the oxygenates are converted catalytically into olefins with high selectivity for lower olefins, and the reaction mixture leaving the fixed-bed zone is separated into a first product stream comprising C2- to C3-olefins and inert gas components, at least one second product stream comprising C4+-olefins, and a third product stream consisting of aqueous phase. In order to improve the yield of lower olefins, the aim is to regulate the temperature of the catalytic reaction in accordance with a target temperature value in the range from 440 to 520° C. specified for the reaction mixture exiting the fixed-bed zone by means of a supplementary stream consisting of olefins and inert gas components fed into the feed stream. ## Claims ### Claim 1 Process for the preparation of C2- to C4-olefins from a feed stream comprising vapor-form oxygenates and steam and having a temperature of from 280 to 480° C., which is passed through at least one fixed-bed zone (3) arranged in a reactor (2) and formed from a bed of granular, shape-selective zeolite catalyst of the pentasil type, and the oxygenates are converted catalytically into olefins with high selectivity for lower olefins at a reaction temperature of from 350 to 550° C. and the reaction mixture exiting the reactor is separated into a first product stream comprising C2- to C3-olefins and inert gas components, at least one further, second product stream comprising C4+-olefins, and a third product stream consisting of aqueous phase, characterized in that a reaction pressure of from 1.0 to 3.0 bara prevails at the entry of the feed stream into the fixed-bed zone (3) and a reaction pressure of from 0.5 to 2.0 bara prevails at the exit of the reaction mixture from the fixed-bed zone, and the temperature of the catalytic reaction is regulated in accordance with a target temperature value in the range from 440 to 520° C. specified for the reaction mixture exiting the fixed-bed zone by means of a supplementary stream comprising C4+ olefins and inert gas components fed into the feed stream, wherein the target temperature value for the reaction mixture exiting the reactor is measured by means of a temperature sensor beneath the catalyst fixed bed and the temperature of the feed stream entering the reactor and flowing through the catalyst fixed bed is measured by means of a temperature sensor arranged above the catalyst mixed bed. ### Claim 2 (depends on 1) Process according to claim 1, wherein the target temperature value is in the range from 480 to 495° C. ### Claim 3 (depends on 1) Process according to claim 1 wherein, the C4+-olefins in the second product stream together with the inert gas components and the ethylene in the first product stream are recycled into the feed stream as supplementary stream. ### Claim 4 (depends on 1) Process according to claim 1 wherein the inert gas components employed comprise steam, nitrogen, helium, neon, argon, hydrogen, carbon monoxide, carbon dioxide, C1- to C4-paraffins and mixtures thereof. ### Claim 5 (depends on 1) Process according to claim 1 wherein the supplementary stream comprises C2- to C8-olefins. ### Claim 6 (depends on 5) Process according to claim 5 wherein the supplementary stream further comprises C2-olefins and C4- to C6-olefins. ### Claim 7 (depends on 5) Process according to claim 5 wherein the supplementary stream further comprises C1- to C8-paraffins. ### Claim 8 (depends on 5) Process according to claim 5 wherein the supplementary stream further comprises C5- to C8-naphthenes. ### Claim 9 (depends on 5) Process according to claim 5 wherein the supplementary stream further comprises C6- to C7 aromatic compounds. ### Claim 10 (depends on 1) Process according to claim 1 wherein by-product streams arising in thermal cracking, catalytic cracking or similar processes are employed as supplementary stream. ### Claim 11 (depends on 1) Process according to claim 1 wherein process-inherent recycling streams are employed as supplementary stream. ### Claim 12 (depends on 1) Process according to claim 1 wherein the throughput of the oxygenates present in the feed stream is from 0.1 to 10 kg, per hour and per kg of catalyst employed. ### Claim 13 (depends on 12) Process according to claim 12 wherein the throughput of the oxygenates is from about 0.3 to 1.5 kg/her per kg of catalyst used. ### Claim 14 (depends on 1) Process according to claim 1 wherein the feed stream fed to a reactor having a plurality of fixed-bed zones is split into a number of feed sub-streams corresponding to the number of fixed-bed zones, and each feed sub-stream is fed to a corresponding fixed-bed zone, the reaction mixture discharged from a fixed-bed zone is fed to the subsequent fixed-bed zone, and the reaction mixture discharged from the final fixed-bed zone in the downstream direction is fed to a separation unit, a supplementary stream comprising olefins and inert gas components is split into a number of supplementary sub-streams corresponding to the number of feed sub-streams, and each supplementary sub-stream is fed into a corresponding feed sub-stream or into the reaction mixture exiting a fixed-bed zone and fed to the subsequent fixed-bed zone. ### Claim 15 (depends on 14) Process according to claim 14 wherein the reactor has between two to six fixed bed zones. ### Claim 16 (depends on 1) Process according to claim 1 wherein the oxygenates are selected from methanol, dimethyl ether and mixtures thereof. ### Claim 17 (depends on 1) Process according to claim 1 wherein the reaction temperature is in the range of about 420° C. to about 490° C. ### Claim 18 (depends on 1) Process according to claim 1 wherein the C2- to C4-olefin that is produced in the process is propylene. ### Claim 19 (depends on 1) Process according to claim 1 wherein the inert gas components in the supplementary stream comprise one or more of steam, nitrogen, helium, neon, argon, hydrogen, carbon monoxide and carbon dioxide.