A Review on the Conversion of Synthetic Gas to LPG over Hybrid Nanostructure Zeolites Catalysts

Recently, Liquified petroleum gas (LPG) attracts wide applications due to its high heating value and clean combustibility. An innovative approach to synthesis of LPG from syngas was established based on Fisher-Tropsch (F-T) technology. However, the conversion and selectivity are generally low with the classical catalysts. The hybrid system of methanol and zeolite-based catalyst was established as a potential approach to promote such a process. To strongly overcome the large demand of LPG and grasp the research work in this subject, a comprehensive review became necessary. LPG is basically produced from syngas through the direct method, where most recent studies lay on, and the indirect or semi direct approach. There were several factors affecting the process performance, which mainly are the reaction temperature, reaction pressure, type of the hybrid catalyst, carbon monoxide to hydrogen ratio, mixture flow rate, and time-on-stream of the reaction. The most common reaction conditions reported in the literature are 260-400 degrees C, 10-50 bars and H-2 to CO ratio of 2. However, the most important parameter considered was the catalyst, which is a key factor of interest. The two main issues controlling the catalyst performance were the synergetic effect between the two hybridized catalysts and the used type of zeolite. It was perceived that the higher the zeolite membered rings the better the LPG selectivity (i. e., BEA, and USY provided the higher LPG production rate).