Biochar potential evaluation of palm oil wastes through slow pyrolysis: Thermochemical characterization and pyrolytic kinetic studies

This research investigated the potential of palm kernel shell (PKS), empty fruit bunch (EFB) and palm oil sludge (POS), abundantly available agricultural wastes, as feedstock for biochar production by slow pyrolysis (50 mL min−1 N2 at 500 °C). Various characterization tests were performed to establish the thermochemical properties of the feedstocks and obtained biochars. PKS and EFB had higher lignin, volatiles, carbon and HHV, and lower ash than POS. The thermochemical conversion had enhanced the biofuel quality of PKS-char and EFB-char exhibiting increased HHV (26.18-27.50 MJ kg−1) and fixed carbon (53.78-59.92%), and decreased moisture (1.03-2.26%). The kinetics of pyrolysis were evaluated by thermogravimetry at different heating rates (10-40 °C). The activation energies determined by Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa models were similar, and comparable with literature data. The findings implied that PKS and EFB are very promising sources for biochars synthesis, and the obtained chars possessed significant biofuel potential.