Effect of calcium and magnesium catalyst on pyrolysis kinetic of Indonesian sugarcane bagasse for biofuel production

The present study aims to investigate the effect of CaO and MgO as catalyst in pyrolysis of Indonesian sugarcane bagasse (SCB) for biofuel production. Prior to being used as raw material, SCB underwent acid washing to remove its inherent Ca and Mg content. Catalytic and non-catalytic pyrolysis experiment were performed in a fixed-bed reactor within a temperature range of 20-480oC. Thermogravimetric Analysis was used to describe the mechanism of pyrolysis and one-step global model was employed to determine the reaction kinetics. Pyrolysis stage comprised of a rapid decomposition zone (260-340oC) and slow decomposition zone (340-480oC). TG curve confirmed that the endothermic cellulose decomposition and volatilization was more dominant than exothermic polymerization and aromatization of lignin. Moreover, CaO provided the highest reaction kinetics with the lowest reaction order compared with catalytic pyrolysis with MgO and non-catalytic process, both in rapid and slow zone. Differential Thermal Analysis (DTA) and Differential Thermal Gravimetric (DTG) corresponded to this by showing that the energy for decomposition in non-catalytic process and using MgO and without catalyst was higher than SCB0-Ca which gave the highest conversion rate. Hence, this study shows that the addition of CaO as catalyst can improve the kinetics of SCB pyrolysis.