Pyrolytic performance and kinetic analysis of non-catalytic and catalytic pyrolysis of bamboo powder and red algae

Abstract

This study explored the impact of ZSM, KOH, and biochar catalysts on the pyrolysis behaviour and reaction kinetics of bamboo powder (BP) and red algae (RA). Thermogravimetric analysis (TGA) was conducted across catalyst concentrations of 6–12% to assess the pyrolysis process. The physicochemical characteristics of BP and RA were analysed, and three key pyrolysis performance indicators (i.e., the comprehensive pyrolysis index, devolatilization index, and pyrolysis stability index) were evaluated. The kinetic triplet was evaluated using the Friedman method combined with master plot analysis. The synergistic effect was also examined. Thermal degradation characteristics, including maximum degradation temperature and rates, varied with catalyst addition. Compared to non-catalytic pyrolysis, catalytic pyrolysis exhibited lower pyrolysis performance indicator values, although increasing the heating rate improved these values. The average activation energy for non-catalytic pyrolysis was 123.70 kJ/mol for BP and 152.18 kJ/mol for RA, but catalyst addition caused notable variations. For BP, average activation energy ranged from 110.97 to 141.90 kJ/mol with KOH, 114.82 to 125.29 kJ/mol with ZSM, and 108.13 to 125.97 kJ/mol with biochar. For RA, it ranged from 116.85 to 154.78 kJ/mol with KOH, 152.27 to 205.39 kJ/mol with ZSM, 148.70 to 174.88 kJ/mol with biochar. These findings offer valuable insights into the effects of catalysts on lignocellulosic and algal biomass feedstocks, shedding light on the underlying mechanisms and process efficiencies of pyrolysis.