Synthesis of LPG from synthesis gas

Synthesis of liquefied petroleum gas (LPG) from synthesis gas using hybrid catalyst consisting of methanol synthesis catalyst and zeolite was investigated in a fixed bed reactor. Experimental results demonstrated that in the hybrid catalyst system, methanol formed from synthesis gas over methanol synthesis catalyst firstly converted into dimethyl ether and then into hydrocarbons over zeolite employed. The composition of the hybrid catalyst had great effects on the activity and selectivity of the catalysts. Distribution of hydrocarbon products depended on characteristics of zeolites employed, while the activity of the catalyst highly depended on the characteristics of methanol synthesis catalysts. The synergetic effect of zeolite and methanol synthesis catalyst brought about a high yield of hydrocarbons, which was far higher than the calculation value based on the thermodynamic equilibrium of methanol formation from synthesis gas. The hybrid catalyst, which consisted of USY zeolite and methanol synthesis catalyst (Cu/ZnO), demonstrated a highly effective formation of light hydrocarbons and the selectivity for C3 and C4 hydrocarbons was more than 75%.