Reduced Foulant Formation During the Selective Hydrogenation of C2, C3, and C4 Acetylenes

Abstract

Catalyst deactivation during the selective hydrogenation of acetylene, methyl acetylene, ethyl acetylene and vinyl acetylene over copper-based catalysts has been examined in a dynamic flow system. In all cases, hydrogenation produced defines and oligomeric material, referred to as green oil or foulant, but no alkanes, proving that copper-based catalysts are highly selective. Catalyst deactivation was observed as a result of the deposition of foulant on the catalyst surface to block active sites. The formation of foulant decreased at higher operating temperatures and was also less when basic or neutral catalyst supports were used. The decrease in foulant production was reflected in decreased catalyst deactivation. However, deactivation also depended on the nature of the alkynes and increased in the order ethyl acetylene and methyl acetylene ≪ vinyl acetylene < acetylene.