Patent ID: 6239321
Filing Date: 2001-05-29
Classification: C07C,C10M,C10N

Abstract:
A process for converting lower oligomers of isobutylene or optionally a mixture of isobutylene and a minor amount of n-butenes in a feedstock containing less than about 45 weight percent of higher oligomers thereof, comprising:(a) fractionating a mixture of from about one part by weight of the aforesaid feedstock and from about 1 to about 30 parts by weight of the oligomerization product recycled in step (c), to thereby separate the aforesaid lower oligomers from a fraction comprising the aforesaid higher oligomers;(b) oligomerizing to a predetermined extent the aforesaid lower oligomers separated in step (a) under conditions such that an oligomerization product mixture is formed comprising higher oligomers and unreacted lower oligomers;(c) recycling the oligomerization product mixture from step (b) to step (a); and(d) recovering the higher oligomer fraction separated in step (a);wherein the fractionation and oligomerization are performed under predetermined conditions such that the higher oligomer fraction recovered in step (d) comprises less than about 20 weight percent of lower oligomers, at least about 60 weight percent of higher oligomers, a weight ratio of pentamers to dimers of at least about 50, and a weight ratio of tetramers to dimers of at least about 60 and less than about 20 weight percent of heptamers and above.