Catalytic Hydroprocessing of Chlorinated Olefins

Substantial quantities of chlorinated alkanes and chlorinated olefins are found in industrial waste streams. The hydrodechlorination reactions of tetrachloro-, trichloro-, 1,1-dichloro-, cis-dichloro-, and trans-dichloroethylenes were examined over a commercial NiMo/Al{sub 2}O{sub 3} catalyst in a packed bed microreactor. The reactor was operated at 1,500 psig and at temperatures between 175 and 275 C. Rates of hydrodechlorination of the chlorinated olefins were much faster than the rates for hydrodechlorination of chlorobenzene, chlorophenols, and chloropyridinols over the same catalyst. Multiple chlorine removal steps appear to be the dominant pathway for hydrodechlorination of olefins as opposed to sequential removal with desorption of intermediates.