CO2/CO Hydrogenation for the Production of Liqhter Hydrocarbons over Bifunctional Co/SAPO-34 Catalyst

Abstract

There has been recently a revival of interest in eco-friendly fuels and alternative route for the clean fuel production. In Gas-to-Liquids (GTL) process, Fischer-Tropsch synthesis (FTS) is known as the catalytic reactions which convert syngas (CO + H2) to value added hydrocarbon products. In this study, CO2 was added to the feed to reduce the greenhouse gases and utilize the captured CO2 in an economic and environmental-friendly way. This can lead to the production of a green fuel. The SAPO-34 was synthesized by hydrothermal method. Cobalt with various loading was impregnated on SAPO-34. The physiochemical properties of all prepared catalysts have been characterized using XRD, N2 physisorption, TPR, FESEM, TEM and NH3-TPD techniques. The effect of CO2/CO ratio in the feed was investigated on conversion and product distribution. The catalytic performance of Co/SAPO-34 catalysts in the FTS has been evaluated in a fixed bed reactor and the products were analyzed by on-line GC and GC-MS. The catalytic performance over Co/SAPO-34 catalysts were compared with Co/Al2O3. The results show that Co/SAPO-34 can produce higher amount of green fuel in comparison to Co/Al2O3. It was found that Co/SAPO-34 catalyst can produce lighter hydrocarbon than Co/Al2O3. It was considered that the heavy hydrocarbons produced on Co will be hydrocracked on acid sites of SAPO-34 zeolite and will be converted to lighter hydrocarbons in the range of fuel cuts. The results show that there is an optimum value for CO2/CO ratio in the feed for different cobalt loadings.