Direct Synthesis of Liquefied Petroleum Gas from Carbon Dioxide Using Modified SBA-15 Hybrid Catalyst

Research Subject: 

The conversion of carbon dioxide into hydrocarbons is a potential process that can reduce and control greenhouse gases. According to the United Nations Development Program's sustainable development goals, liquefied gas is an environmentally friendly fuel. Hydrogenation of carbon dioxide over a suitable catalyst can be used directly to synthesize light hydrocarbons.

Research Approach: 

This study investigated the direct synthesis of liquefied petroleum gas from carbon dioxide hydrogenation using SBA-15 catalyst modified with copper and zinc nanoparticles. In this study, hydrogen and carbon dioxide were used as reactant gases, and the operation conditions such as reaction temperature and residence time were evaluated.

The results showed that by modifying the catalyst with copper and zinc active sites, the active surface of the catalyst was reduced to 542 m2.g-1. Furthermore, SEM results revealed that the addition of metal oxides ZnO and CuO resulted in uniform distribution in the internal channels of the 1Cu1Zn/SBA-15 catalyst, with no aggregation. LPG production is optimal at a temperature of 360 oC and a residence time of 10 g.h.mol-1. These conditions yielded a CO2 conversion rate of 24.6% and a LPG selectivity of 64.8%, respectively. The amount of LPG produced increases as the temperature rises, and after reaching the optimum temperature, there is no significant increase in the amount of LPG produced. The percentage of CO2 conversion does not change much when the residence time is increased after the optimum value, indicating that the reaction has reached its thermodynamic theoretical range. According to the catalytic lifetime test of 1Cu1Zn/SBA-15, CO2 conversion percentage and LPG selectivity do not change after 85 hours. Based on the results of the experiments, the synthesized catalyst can hydrogenate CO2 efficiently to LPG.