Direct synthesis of hydrocarbon by carbon dioxide hydrogenation was investigated over hybrid catalysts composed of methanol synthesis catalysts and zeolites. Hydrogenation of carbon monoxide was also carried out over the same catalysts. Cu-Zn-Zr and Cu-Zn-Al were used as methanol synthesis catalyst. HZSM-5,DAY and SAPO-5 were used as methanol to hydrocarbon catalyst.
The reaction was carried out in a continuous micro flow reactor with a fixed bed under various reaction conditions.
The main product in $CO_2$ hydrogenation over (Cu-Zn-Zr + HZSM-5) hybrid catalyst was ethane and the yield of $C_2^{+}$ hydrocarbons increased with decreasing $Si/Al_2$ ratio. The hybrid catalyst composed of Cu-Zn-Zr and SAPO-5 was effective for the synthesis $C_2-C_5$ hydrocarbon. $CO_2$ conversion increased with reaction temperature, but maximum yield of $C_2^{+}$ hydrocarbon was obtained at 370℃. An increase in contact time lowered the CO formation and increased the hydrocarbon formation. In $CO_2/CO/H_2$ feed system the yield of hydrocarbon increased with increasing CO concentration.
