Solid phosphoric acid catalyzed olefin polymerization process
AssigneeChevron Research Company
InventorJohn F. Manning
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Abstract
Improved processes for polymerizing C.sub.3 -C.sub.12 olefins (e.g. propylene) comprising polymerizing olefins in the presence of a solid phosphoric acid catalyst and an alkanol. As well as catalyzing the polymerization, the catalyst also catalyzes the decomposition of the alkanol into water and olefin. The water in turn replaces water lost from the catalyst during the polymerization thus maintaining a more constant phosphoric acid strength catalyst without subjecting said catalyst to excess liquid water and substantially improving overall polymerization conversions and catalyst life.
Claims9
In a process for polymerizing C.sub.3 -C.sub.12 olefins to produce lower polyolefins which comprises contacting a mixed liquid/vapor olefin feed stream with a solid phosphoric acid catalyst having a siliceous support under polymerization conditions, the improvement wherein said catalyst has a phosporic acid strength in the range of about from 100 to 108 wt. %, and said olefin feed stream comprises an amount of an alkanol, selected from the group consisting of alkanols which are reactive at the polymerization conditions used for said process to decompose at yields of at least 50% upon contact with said solid phosphoric acid catalyst under said polymerization conditions generating water as a decomposition product, effective to maintain the phosphoric acid strength of said catalyst within said range by replacing at least a portion of the water discharged from said catalyst during said polymerization with water generated by decomposition of said alkanol.
Dependencies are inferred from the claim text.