LPG olefins (propene and butenes) are key building blocks in the petrochemical industry whose demand has been expanding\nsteadily in recent years. The use of FCC (fluid catalytic cracking) units for conversion of triglycerides is a promising option for the\nfuture to boost production of LPG olefins. However, a need for innovative cracking catalysts is rising due to the different nature\nbetween petroleum and biomass-derived feedstocks. In this study, series of hierarchical ZSM-5 materials, namely, mesoporous\nZSM-5, nanosized ZSM-5, and composite ZSM-5 were prepared, aiming to enhance the production of LPG olefins along with\ntransportation fuels. Mesoporous ZSM-5 materials were synthesized by the postsynthetic modifications involving base treatment\nand subsequent acid washing, whereas nanosized ZSM-5 and composite ZSM-5 were synthesized by the direct-synthetic routes for\na comparative purpose. The obtained materials were characterized by XRD, FTIR, N2 sorption, TEM, AAS, ICP-AES, and NH3-\nTPD, and their catalytic performance was assessed in the cracking of triolein as a representative of triglycerides under FCC\nconditions. It was found that the subsequent strong acid washing step of alkaline treated ZSM-5 for removal of aluminum debris\nand external acid sites is needed to improve the catalytic performance. The resulting mesoporous ZSM-5 material shows higher\nyields of the desired products, i.e., gasoline and LPG olefins than its parent, commercial ZSM-5 at the almost complete conversion\n(ca. 90 wt.%). The selectivity toward LPG olefins is also enhanced over all the hierarchical ZSM-5 materials, particularly high for\ncomposite ZSM-5 (ca. 94 wt.%). The improved diffusion and lowered acidity of the hierarchical ZSM-5 materials might be\nresponsible for their superior catalytic performance.
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