Isobutylene → Isobutylene

Participants

Reaction Steps

A stream of renewable isobutylene (95% from a dehydration reactor fed renewable isobutanol), is heated to 350° C. at 0.25 atm in the presence of 0.4 equivalents of ozone to produce a stream of 1 part isobutylene oxide and 2 parts isobutylene. The stream is partially cooled and fed through a flow reactor charged with niobic acid catalyst at a rate of 40-60 g/hr at 225° C. Enough pressure (600 psi) is applied to keep the reactants in the liquid phase. The excess gas collected is primarily isobutylene and is recycled back to mix with an enriched isobutylene oxide stream to ensure the 1:2 stochiometry detailed above. The liquid effluent is sampled for conversion to 2,5-dimethyl-2,4-hexadiene, which is normally 65% with the remainder being unreacted starting material and a minor portion (5%) of higher isobutylene oligomers. At optimal conditions the reactor is continually run for periods longer than 10 days.

Provenance & Evidence