Multi reaction apparent kinetic scheme for the pyrolysis of large size biomass particles using macro-TGA

In the present study, the pyrolysis of biomass is proposed by one step multi reaction apparent model. It is expressed as parallel production of bio-oil, gases and charcoal. Macro TGA of Jatropha de-oiled cake is performed at temperatures ranging from 350 °C to 700 °C. The volatiles released during pyrolysis exits from the top of the reactor and are cooled in a two-stage condenser followed by an ice trap. The weight reduction variation of the biomass with time, product yield and composition of non condensable gases are measured and used to develop the apparent kinetic model. The corresponding apparent kinetic parameters are estimated by minimizing the square of the error between simulated values of residual weight fraction and experimental values using non-traditional optimization technique logarithmic differential evolution (LDE). The weight reduction with time suggests that the pyrolysis of de-oiled cake is carried out in three stages. The maximum liquid yield obtained is 31.2% at 500 °C, which further decreases with an increase in temperature. The model predicted values of residual weight fractions and yield of products are matching very well with the experimental data for all reactor temperature.