Coproduction of Ethylene and Vinyl Chloride by USC/Occidental Chemical Process

The University of Southern California (USC) and Occidental Chemical Corporation (Oxychem) have been developing a noncatalytic, high-temperature chlorination process to coproduce ethylene and vinyl chloride monomer (VCM) from ethane. The process offers high ethane conversions and high selectivities to both products. The combined yields of those two products exceeds 80 mol% based on ethane.

On the basis of the experimental yield data disclosed in two patent applications submitted by the process developers, SRI estimated the investments and production costs for ethylene and VCM coproduction by the new process for two cases. In one case, both coproducts are marketed; in the alternate case, only enough ethylene is produced to satisfy the needs for producing 800 million pounds (363 thousand metric tons) per year of VCM for sale. SRI's estimates show that for the production and marketing of both ethylene and VCM, the process is not economically competitive with conventional processes. However, if only enough ethylene is produced to satisfy the needs for VCM production, the new process offers an advantage over the conventional VCM production route. This advantage derives largely from savings in feedstock cost--through employing ethane instead of purified ethylene as a VCM feedstock.