Pyrolysis of peanut shell: Kinetic analysis and optimization of thermal degradation process

Thermal degradation kinetics of peanut shell (PS) biomass has been investigated at the heating rates of 10, 15, and 20 degrees C/min using thermo-gravimetric (TG) and differential thermo-gravimetric (DTG) analyses techniques in the temperature range of ambient to 800 degrees C. The iso-conversional methods of Flynn-Ozawa-Wall (FOW), Kissinger-Akahira-Sunose (KAS), Starink, Tang, Vyazovkin, and Vyazovkin AIC have yielded activation energy E alpha,varying from 186 to 226.97 kJ/mol. Effects of heating rate, temperature and nitrogen gas flow rate on the biochar and bio-oil yields have been investigated using a fixed bed batch pyrolyser. The Box-Behenken design (BBD) of response surface methodology (RSM) has been used to optimize the process parameters. The average values of bio-oil and bio-char yields at the optimum conditions have been found to be 43.24 and 28.25 %, respectively. The product bio-oil is highly acidic and has the higher heating value (HHV) of 26.49 MJ/kg and the bio-char is rich in micronutrients.