Systems and processes disclosed may be used to produce a high purity isobutane stream and a high purity 1-butene stream from mixed C4 streams having disparate starting compositions.

Systems and processes disclosed may be used to produce a high purity isobutane stream and a high purity 1-butene stream from mixed C4 streams having disparate starting compositions.

A method of producing a fuel additive includes: passing a raffinate stream comprising C4 hydrocarbons through a hydrogenation unit, forming a first process stream; passing the first process stream through an extractive distillation unit, forming a C4 olefin stream; passing the C4 olefin stream through a stripper column, forming a purified C4 olefin stream; and forming the fuel additive by passing the purified C4 olefin stream through a hydration unit.

A method of producing a fuel additive includes: passing a raffinate stream comprising C4 hydrocarbons through a hydrogenation unit, forming a first process stream; passing the first process stream through an extractive distillation unit, forming a C4 olefin stream; passing the C4 olefin stream through a stripper column, forming a purified C4 olefin stream; and forming the fuel additive by passing the purified C4 olefin stream through a hydration unit.

A process for component separation in a polymer production system, comprising: separating a polymerization product stream into a gas stream and a polymer stream; contacting the polymer stream with a purge gas to yield a purged polymer stream and a spent purge gas stream; introducing the spent purge gas stream to a compressor to produce a compressed gas stream; introducing the compressed gas stream to a first separation unit to produce a first hydrocarbon stream and a membrane unit feed stream; introducing the membrane unit feed stream to a membrane unit to produce a first recovered purge gas stream and a retentate stream; introducing the retentate stream to a second separation unit to produce a second hydrocarbon stream and a PSA unit feed stream; and introducing the PSA unit feed stream to a PSA unit to produce a second recovered purge gas stream and a tail gas stream.

A process for component separation in a polymer production system, comprising: separating a polymerization product stream into a gas stream and a polymer stream; contacting the polymer stream with a purge gas to yield a purged polymer stream and a spent purge gas stream; introducing the spent purge gas stream to a compressor to produce a compressed gas stream; introducing the compressed gas stream to a first separation unit to produce a first hydrocarbon stream and a membrane unit feed stream; introducing the membrane unit feed stream to a membrane unit to produce a first recovered purge gas stream and a retentate stream; introducing the retentate stream to a second separation unit to produce a second hydrocarbon stream and a PSA unit feed stream; and introducing the PSA unit feed stream to a PSA unit to produce a second recovered purge gas stream and a tail gas stream.

A process for component separation in a polymer production system, comprising: separating a polymerization product stream into a gas stream and a polymer stream; contacting the polymer stream with a purge gas to yield a purged polymer stream and a spent purge gas stream; introducing the spent purge gas stream to a compressor to produce a compressed gas stream; introducing the compressed gas stream to a first separation unit to produce a first hydrocarbon stream and a membrane unit feed stream; introducing the membrane unit feed stream to a membrane unit to produce a first recovered purge gas stream and a retentate stream; introducing the retentate stream to a second separation unit to produce a second hydrocarbon stream and a PSA unit feed stream; and introducing the PSA unit feed stream to a PSA unit to produce a second recovered purge gas stream and a tail gas stream.

Processes incorporating a common organic chloride decomposition reactor and chloride treater to be used by both the C.sub.4 and C.sub.5-6 isomerization reaction zones are described. A portion of the C.sub.4 isomerization reaction zone off gas is routed to the C.sub.4 HCl absorber, which provides about 85% of the HCl requirement for the C.sub.4 isomerization reaction zone. A small amount of the C.sub.5-6 isomerization reaction zone off gas is mixed with the C.sub.4 isomerization reaction zone off gas portion going to the C.sub.4 HCl absorber.

Processes incorporating a common organic chloride decomposition reactor and chloride treater to be used by both the C.sub.4 and C.sub.5-6 isomerization reaction zones are described. A portion of the C.sub.4 isomerization reaction zone off gas is routed to the C.sub.4 HCl absorber, which provides about 85% of the HCl requirement for the C.sub.4 isomerization reaction zone. A small amount of the C.sub.5-6 isomerization reaction zone off gas is mixed with the C.sub.4 isomerization reaction zone off gas portion going to the C.sub.4 HCl absorber.

Processes for the production of high purity isobutylene are disclosed. The processes may include supplying a mixed C4 feed stream to a catalytic distillation column, which may contain a butene isomerization catalyst. 1-butene is isomerized to 2-butene and concurrently in the catalytic distillation column the 2-butene is separated from the isobutane and isobutylene. The overheads fraction comprising the isobutane and isobutylene is then condensed in an overheads system and fed to a splitter, where the isobutane is separated from the isobutylene. The process further includes operating the catalytic distillation column at an overheads temperature greater than a bottoms temperature of the splitter, and heating a portion of the splitter bottoms stream via indirect heat exchange with at least a portion of the catalytic distillation column overheads fraction, thereby producing a heated bottoms stream (reboil vapor) fed to the splitter and a cooled overheads fraction.