دانلود رایگان مقاله تبدیل لوولینیک اسید به BTX بر کاتالیزور های مختلف زئولیت

Abstract

Zeolites having a different pore size, pore geometry and acidity (small pore FER, medium pore ZSM-5, and large pore Y, BEA and MOR) were investigated for the conversion of levulinic acid (LA) to aromatics (BTX). Product selectivity was found to depend on pore size and radius of the zeolites. In addition to pore size, internal pore space, and steric hindrance play a determining role in aromatics production. ZSM-5 with moderate internal pore space and steric hindrance gave the highest BTX yield of 31% and least amount of coke. The high aromatic yield of ZSM-5 has been attributed to its strong acidity for cracking and suitable pore structure for aromatization.

4. Conclusions

In the present endeavor, we have been trying to see the impact of 1) acidity, ii) pore size, iii) pore volume, iv) and pore geometry on the conversion of LA to BTX and coke formation. Among all the catalysts, ZSM-5 possesses the maximum number of weak and strong acid sites and produced a maximum BTX yield of 25%. However, no straightforward relationship was observed among other zeolites acidity and BTX yield indicating that pore size and pore structure are more important than acidity. ZSM-5 with three-dimensional pore geometry and moderate internal pore space gave the highest BTX yield and least coke. Large pore beta and HY with three-dimensional pore geometries gave lower BTX yields and high coke formation compared to MOR with one-dimensional pore geometry. Thus, by the proper choice of zeolite topology, it is possible to obtain excellent yield of BTX from LA.