PROCESS FOR THE PREPARATION OF AN OLEFINIC PRODUCT COMPRISING ETHYLENE AND/OR PROPYLENE

摘要

The invention provides a process for the preparation of an olefinic product comprising ethylene and/or propylene comprising: a) steam cracking a paraffinic feedstock to obtain an effluent comprising olefins; b) converting an oxygenate to obtain a gaseous effluent comprising olefins; c) subjecting both effluents to water removal and compression steps, wherein the effluents are combined before the water removal step, between the water removal and the compression steps or after the compression step to obtain a combined gaseous effluent; d) removing acid gas from the combined gaseous effluent obtained in step c), wherein the combined gaseous effluent is treated with a caustic solution in a caustic tower and a non-aqueous liquid stream comprising one or more aromatic C7+ hydrocarbons is added to the caustic solution to control the formation of red oil, to obtain a treated gaseous effluent; and e) separating the olefinic product from the treated gaseous effluent.

主权项

1. A process for the preparation of an olefinic product comprising ethylene and/or propylene, the process comprising the following steps:
a) steam cracking a paraffinic feedstock under cracking conditions in a cracking zone to obtain a cracker effluent comprising olefins, water, carbon dioxide and carbonyl compounds including C2+ aldehyde and/or ketone; b) contacting an oxygenate feedstock in an oxygenate conversion reaction zone with a molecular sieve-comprising catalyst at a temperature in the range of from 350 to 1000° C. to produce an oxygenate conversion effluent comprising olefins, water, carbon dioxide and carbonyl compounds including C2+ aldehyde and/or ketone; c) subjecting both the cracker effluent and the oxygenate conversion effluent to a water removal step followed by a compression step with optional recovery of any condensed hydrocarbons in the water removal step and/or in the compression step, wherein the cracker effluent and the oxygenate conversion effluent are combined prior to the water removal step or after the water removal step and before the compression step, to obtain a combined compressed water-depleted gaseous stream comprising olefins, carbon dioxide and carbonyl compounds; d) separating carbon dioxide from the combined compressed water-depleted gaseous stream by subjecting the gaseous stream to a caustic wash treatment in a caustic tower wherein the gaseous stream is countercurrently contacted with a caustic solution to obtain a washed gaseous stream comprising olefins; and e) subjecting the washed gaseous stream to one or more separation steps such that at least an olefin product stream comprising ethylene and/or propylene is obtained,wherein in step d) a non-aqueous liquid stream comprising one or more aromatic C7+ hydrocarbons is added to the caustic solution prior to contacting the caustic solution with the gaseous stream and wherein a liquid phase comprising spent caustic solution and the one or more aromatic C7+ hydrocarbons is discharged from the caustic tower.