Etherification--hydrogenation process
AssigneeChemical Research & Licensing Company
InventorsDennis Hearn, Gary R. Gildert, Willibrord A. Groten
Life of this patent
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Abstract
A process for removing dienes from etherification uses a hydrogenation zone in the reactor distillation column above the etherification zone. MTBE is produced and the unreacted C.sub.4 stream is also subjected to selective hydrogenation of the butadiene contained in the C.sub.4 feed stream. The C.sub.4 stream is first contacted with methanol in the etherification zone where the MTBE is distilled downward. The unreacted C.sub.4 's then are subjected to selective hydrogenation in the hydrogenation zone where butadiene in the overhead raffinate is reduced by over 90%. The hydrotreated C.sub.4 's are thus suitable for cold acid alkylation or other use wherein butadiene is harmful.
Claims17
A process for the production of alkyl tertiary alkyl ether and hydrogenation of the dienes contained in an isoalkene containing stream used for the etherification, comprising the steps of:
- (a) feeding a first stream containing isoalkene and diene, a second stream containing alcohol and a third stream containing hydrogen to a distillation column reactor into a feed zone;
- (b) contacting the streams in an etherification reaction distillation zone containing an etherification catalyst to:
- (i) selectively react at least a portion of the isoalkene with a portion of the alcohol to form alkyl tertiary alkyl ether,
- (ii) distill the alkyl tertiary alkyl ether downward out of the etherification reaction distillation zone and
- (iii) distill the unreacted isoalkene, alcohol, diene and hydrogen upward out of the etherification reaction distillation zone;
- (c) contacting the unreacted isoalkene, alcohol, diene and hydrogen in a hydrogenation reaction distillation zone containing a hydrogenation catalyst to selectively hydrogenate a portion of the dienes to alkenes;
- (d) withdrawing ether product from the distillation column reactor as bottoms;
- and
- (e) withdrawing an overheads stream from the distillation column reactor having a reduced diene content as compared to the diene content of the first stream.
A process for the production of methyl tertiary butyl ether and hydrogenation of the butadiene contained in the C.sub.4 stream used for the etherification, comprising the steps of:
- (a) feeding a first stream containing isobutene and butadiene, a second stream containing methanol and a third stream containing hydrogen to a distillation column reactor into a feed zone;
- (b) contacting the streams in an etherification reaction distillation zone containing an etherification catalyst to
- (i) selectively react at least a portion of the isobutene with a portion of the methanol to form methyl tertiary butyl ether,
- (ii) distill the methyl tertiary butyl ether downward out of the etherification reaction distillation zone and
- (iii) distill the unreacted isobutene, methanol, butadiene and hydrogen upward out of the etherification reaction distillation zone;
- (c) contacting the unreacted isobutene, methanol, butadiene and hydrogen in hydrogenation reaction distillation zone containing a hydrogenation catalyst to selectively hydrogenate a portion of the butadiene to butenes;
- (d) withdrawing ether product from the distillation column reactor as bottoms;
- and
- (e) withdrawing an overheads stream from the distillation column reactor having a reduced butadiene content as compared to the butadiene content of the first stream.
In a process for the production of methyl tertiary butyl ether using a C.sub.4 stream from a fluid catalytic cracking unit in a distillation column reactor having an etherification reaction distillation zone, the improvement comprising placing a hydrogenation reaction distillation zone above the etherification reaction distillation zone to hydrogenate a portion of the butadiene contained in the C.sub.4 stream.
A process for the production of alkyl tertiary alkyl ether and hydrogenation of the dienes contained in an isoalkene containing stream used for the etherification, comprising the steps of:
- (a) feeding a first stream containing alkyl tertiary alkyl ether isoalkene, diene and alcohol and a second stream containing hydrogen to a distillation column reactor into a feed zone;
- (b) distilling the alkyl tertiary alkyl ether downward out of a distillation zone and
- (c) distilling the unreacted isoalkene, alcohol, diene and hydrogen upward out of said distillation zone;
- (d) contacting the unreacted isoalkene, alcohol, diene and hydrogen in a hydrogenation reaction distillation zone containing a hydrogenation catalyst prepared as a distillation structure to selectively hydrogenate a portion of the dienes to alkenes;
- (e) withdrawing ether product from the distillation column reactor as bottoms;
- and
- (f) withdrawing an overheads stream from the distillation column reactor having a reduced diene content as compared to the diene content of the first stream.
Dependencies are inferred from the claim text.