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US 7,402,720 B2Granted
Distillation process for removal of methyl acetylene and/or propadiene from an olefin stream
AssigneeExxonMobil Chemical Patents Inc.
InventorCor F. Van Egmond
Life of this patent
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Abstract
The present invention provides a process for removing methyl acetylene and/or propadiene from a propylene stream and/or a butylene stream by two step fractionation. Methyl acetylene and/or propadiene avoids the use of a hydrogenation reactor and makes the methyl acetylene and/or propadiene recoverable from the process.
Claims40
A process for producing a stream of propylene and a stream of butylene from an olefin stream, the process comprising the steps of:
- (a) providing a reactor effluent from an oxygenates-to-olefins process as an olefin stream comprising propylene, MAPD, dimethyl ether, and butylene;
- (b) fractionating the olefin stream thereby producing a first overhead stream and a first bottoms stream, such that the first overhead stream comprises propylene, comprises from about 5 ppbw to about 1000 ppbw dimethyl ether based on the weight of the first overhead stream, and is substantially free of MAPD, and such that the first bottoms stream comprises MAPD and butylene, wherein no propane is added to said reactor effluent before this olefin stream is fractionated in this step (b);
- and
- (c) fractionating the first bottoms stream thereby producing a second overhead stream and a second bottoms stream, such that the second overhead stream comprises MAPD and such that the second bottoms stream comprises about 10 wt. % or more butylene, wherein the second bottoms stream is substantially free of MAPD.
1 more element
A process for separating MAPD from a propylene stream,
- (a) providing a first stream derived from a reactor effluent from an oxygenates-to-olefins process, said first stream comprising propylene, MAPD, and dimethyl ether and wherein no propane is added to said reactor effluent before said first stream derived from said effluent is separated in step (b);
- and
- (b) separating said first stream into a second stream and a third stream, such that the second stream contains propylene and such that the third stream contains MAPD and dimethyl ether, wherein the concentration of MAPD in the second stream is less than 10 ppmw based upon the weight of the second stream, the second stream further comprises from about 5 ppbw to about 1000 ppbw dimethyl ether based upon the weight of the second stream, and the concentration of propylene in the third stream is less than 1 ppmw based upon the weight of the third stream.
Dependencies are inferred from the claim text.