Olefins can limit desulfurization of reformer feedstock

Pilot plant studies have shown that the presence of even very small amounts of olefins may limit the desulfurization of reformer feedstocks to trace levels. The recombination reaction of olefins with hydrogen sulfide to form mercaptans was studied. The advantage of using highly active (third generation) CoMo hydrotreating catalysts can be masked by these reactions if the olefins are not saturated. Hydrotreating of naphtha using high-rhenium, bimetallic catalysts was studied in particular.