Study on thermochemical conversion of triglyceride biomass catalyzed by biochar catalyst

Abstract

This study investigates the fast catalytic pyrolysis of rubber seed oil over a CO2-activated biochar catalyst in the temperature range of 600–800 °C, producing high-value products. The effect of activation time on the catalytic performance and the possibility of using the deactivated catalyst as fuel are also examined. The results indicate that extending the activation time can increase the specific surface area and oxygen active sites of biochar catalyst, thereby improving the catalytic performance. At optimum temperature (800 °C), the biochar catalysts increase the syngas yield from 507.90 mL/g to 634.51 mL/g while facilitating the conversion of polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons. Consequently, the yield of monocyclic aromatic hydrocarbons is increased from 3.72 wt% to 55.77 wt%. Out of the monocyclic aromatic hydrocarbons, benzene and its derivatives are important chemicals, with a yield of 46.80 wt%. Besides, microporous channels in biochar catalysts inhibit the generation of coke, reducing the coke yield from 13.57 to 5.59 wt%; the coke deposit on biochar catalyst is pyrolytic coke. The high heating value of the deactivated biochar catalyst reach 28.605 MJ/kg, and it can be used as a solid fuel. Finally, a mechanism for converting polycyclic aromatic hydrocarbons to monocyclic aromatic hydrocarbons during the fast catalytic pyrolysis of the rubber seed oil is proposed.