Butene-1 from MTBE Plant Raffinate

This review presents an evaluation of the recovery of pure (99+ wt%) butene-1 from the residual C4 mixture leaving an MTBE unit. The latter is operated on a steam-cracked mixed butenes feed (raffinate from a butadiene recovery unit) at high isobutylene conversion and is described separately in PEP Report No. 131 (Section 4, Case B).

Pure butene-1 is used as a comonomer in high- and low-density polyethylene manufacture, and as raw material for polybutene-1. To recover it from the low-isobutylene C4 raffinate of the MTBE plant, butadiene is first removed by selective hydrogenation and butene-1 is then isolated in two close fractionation steps.