Kinetic and thermodynamic analyses during co-pyrolysis of greenhouse wastes and coal by TGA

Abstract

For thermal and kinetic analyses of co-pyrolysis of biomass and coal thermogravimetric analysis (TGA) is usually used to get valuable information for accurate design of co-pyrolysis facilities. In this study, pyrolysis mechanism of the equal mixture of tomato, pepper, and eggplant wastes as greenhouse vegetables wastes (GVW) and its blend with coal was investigated by using TGA with different heating rates. Kinetic and thermodynamic parameters were calculated by using Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. To highlight the synergistic effect between GVW and coal during co-pyrolysis, the deviation between the experimental and calculated values of mass loss and mass loss rate was calculated. The average activation energy (Ea) of 100%wt calculated by FWO and KAS models was 74.27 and 67.00 kJ mol−1, whereas Ea of 0%wt was 133.99 and 129.84 kJ mol−1, respectively. The average Ea of 25%wt was 148.34 and 145.19 kJ mol−1, while it was 57.21 and 49.40 kJ mol−1 for 50%wt. The positive values of deviation indicated the existence of synergistic effect between GVW and coal during co-pyrolysis. The blend of 50%wt with the smallest Ea and ΔS was the best combination for the simultaneous valorization of GVW and coal through pyrolysis.