Back to results
US 4,085,158 AGranted
Isoamylenes from butenes
AssigneePhillips Petroleum Company
InventorsRolland E. Dixon, P. Douglas Hann
Life of this patent
Estimating the term…
Abstract
A feed of mixed butenes is separated by molecular sieves into a butene-1 stream and a stream comprising butenes-2 and isobutene. The butenes-2 and isobutene are disproportionated to yield isoamylenes. The isoamylenes can be converted to isoprene.
Claims22
A method of preparation of isoamylenes from a mixed butenes feed stream comprising butene-1, butenes-2, and isobutene, wherein said process comprises the steps:
- (a) contacting said mixed butenes stream with molecular sieve separation means whereby said butene-1 is substantially adsorbed and said butenes-2 and isobutene pass therethrough as a raffinate,
- (b) disproportionating said raffinate of isobutene and butenes-2 which can futher contain propylene in an effective disproportionation mole ratio of butenes-2 and isobutene, thereby forming a stream comprising isoamylenes, unconverted butenes-2, isobutene, propylene, and which can contain ethylene, wherein said mole ratio is about 1:1 isobutene:
- butenes-2 plus propylene where employed
- (c) separating said stream comprising isoamylenes into streams comprising propylene, butenes-2 and isobutene, said isoamylenes, and optionally an ethylene stream when said isoamylene stream further contains said ethylene,
- (d) recycling said separated butenes-2 and isobutenes to said disproportionating step,
- (e) desorbing said adsorbed butene-1, thereby producing a desorbed butene-1 stream,
- (f) isomerizing said desorbed butene-1 stream at least in part to at least one of further butenes-2, or isobutene, or both, so as to provide an effective mole ratio of butenes-2:
- isobutene for said step (b) in combination with butenes-2 and isobutene from said mixed feed,
- (g) recycling said further butenes-2, isobutene, or both, and any unconverted butene-1, to said molecular sieve separation step,
- (h) dimerizing as necessary at least a proportion of said ethylene when present to produce a dimerized steam of additional butenes and cycling said additional butenes to said step (a), wherein said ethylene dimerization assists in maintaining a proper butenes-2:
- isobutene disproportionation mole ratio for said step (b) thereby providing a method of preparation of isoamylenes from a mixed butenes feed stream providing for internal adjustments in order to provide for a balanced mole ratio for said disproportionation step (b).
8 more elements
A method of preparation of isoprene from a mixed butenes stream comprising butene-1, butenes-2, and isobutene, wherein said process comprises the steps:
- (a) contacting said mixed butenes stream with molecular sieve separation means whereby said butene-1 is substantially adsorbed and said butenes-2, and isobutene pass therethrough as a raffinate stream,
- (b) disproportionating said raffinate stream of isobutene and butenes-2 which can further contain propylene in an effective disproportionation mole ratio of isobutene:butenes-2, thereby forming an isoamylenes stream comprising isoamylenes, unconverted butene-2, isobutene, propylene, and ethylene when present, wherein said mole ratio is about 1:1 isobutene:
- butenes-2 plus propylene where employed
- (c) separating said isoamylenes stream into streams comprising a propylene stream, an ethylene stream when said ethylene is present, separated butenes-2 and isobutene, and said isoamylenes,
- (d) oxidatively dehydrogenating said isoamylenes to said isoprene,
- (e) recycling said separated butenes-2 and isobutene to said disproportionation step (b),
- (f) desorbing said adsorbed butene-1, thereby producing a butene-1 extract stream,
- (g) double bond isomerizing at least a portion of said butene-1 to further butenes-2,
- (h) skeletally isomerizing a further portion of said butene-1 to further isobutene, and
- (i) recycling said further butenes-2 and isobutene, and any unconverted butene-1, to said mixed butenes molecular sieve separation step (a), and
- (j) dimerize as necessary at least a proportion of said ethylene when present to produce a dimerized steam of additional butenes and cycling said additional butenes to said step (a), wherein said ethylene dimerization assists in maintaining a proper butenes-2:isobutene ratio for said step (b), and
- (k) recycling as necessary at least a portion of said propylene from said step (c) to supplement said butenes-2 in order to maintain an effective disproportionation ratio of butene-2 plus propylene:isobutene for said disproportionating step (b), thereby providing a method of preparation of isoprene from a mixed butenes feed stream providing for internal process balancing to provide for a balanced mole ratio for said disproportionation step (b).
9 more elements
Dependencies are inferred from the claim text.