Performance of alkali and Ni-modified ZSM-5 during catalytic pyrolysis of extracted hemicellulose from rice straw for the production of aromatic hydrocarbons

Hemicellulose was extracted from rice straw, and catalyst ZSM-5 was modified by NaOH and Ni over alkaline treatment and wet impregnation method, respectively. To investigate the effects of modified ZSM-5 on selectivity of aromatic hydrocarbons, catalytic pyrolysis of hemicellulose was studied via PyGC/MS. Significant effect has been reported for product selectivity and composition over the modified catalysts. All the modified catalysts showed better aromatic selectivity than parent ZSM-5 (P-ZSM-5). Notably, alkali modified ZSM-5 with 0.4 M concentration of NaOH (0.4 M ZSM-5) showed 36% selectivity towards aromatics with the share of benzene, toluene, and xylene (58%) and share of polyaromatics (15%) compared to others. Meanwhile, 8 wt% Ni-ZSM-5 showed the highest selectivity of aromatic hydrocarbons of 54% where the share of benzene, toluene, and xylene was 70%. This research revealed that metal modified ZSM-5 significantly influences the aromatics yield, which is essential for the production of liquid fuels and chemicals. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates that modifying ZSM-5 with alkali treatment and wet impregnation method can enhance the selectivity and yield of aromatic hydrocarbons. NaOH-modified ZSM-5 and 8 wt% Ni-ZSM-5 show different selectivity towards aromatics.