SYNTHESIS OF MTBE DURING CO HYDROGENATION - REACTION SITES REQUIRED

Synthesis of methyl tert-butyl ether (MTBE) during carbon monoxide (GO) hydrogenation has been studied with the following reaction schemes: (i) the addition of isobutylene during CO hydrogenation over metal catalysts active for methanol synthesis (Pd/SiO2 and Li-Pd/SiO2) and (ii) the addition of isobutylene during CO hydrogenation over a dual bed configuration consisting of Li-Pd/SiO2 and a zeolite (H-ZSM-5 or HY). The addition of isobutylene during methanol synthesis over the supported Pd catalysts indicated that MTBE cannot be formed on metal sites from a reaction of isobutylene with methanol precursors. However, addition of isobutylene to the syngas feed over a dual bed consisting of a methanol synthesis catalyst and an acid zeolite downstream of the methanol synthesis catalyst showed that MTBE can be synthesized during CO hydrogenation provided acid sites are available. In order to get higher conversions of methanol to MTBE, optimization of the acid catalyst and/or reaction conditions would be required to minimize formation of byproduct hydrocarbons.