Patent ID: 11932597
Assignee: LUMMUS TECHNOLOGY LLC
Field: Organic fine chemistry (Chemistry)
Classification: CPC C  Y | IPC C

Claim 18:
19. A process for converting mixed C4 hydrocarbons to propylene, the process comprising:
skeletal isomerizing the mixed C4 hydrocarbons comprising isobutane and isobutene to convert isobutene to n-butenes including 1-butene and 2-butenes and to recover a skeletal isomerization reaction product comprising isobutane, isobutene, butadiene, 1-butene, and 2-butenes;
concurrently:
fractionating the skeletal isomerization reaction product,
isomerizing the 1-butene contained therein to 2-butenes, and
recovering an overhead fraction comprising isobutane, a side draw fraction comprising isobutane and isobutene, and a bottoms fraction comprising 2-butenes;
combining the bottoms fraction with ethylene and converting the ethylene and 2-butenes to produce a reaction effluent comprising propylene;
dehydrogenating the overhead fraction comprising isobutane to produce additional mixed C4 hydrocarbons comprising isobutane and isobutene; and
recycling the side draw fraction comprising isobutane and isobutene to the skeletal isomerizing step.