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 Py-GC/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.