Modelling multicomponent devolatilization kinetics of imperata cylindrica

Abstract

Biomass devolatilization is an important phenomenon in the thermochemical conversion of biomass into clean fuels through pyrolysis, gasification and combustion. In this paper multicomponent model fitting (MMF) was carried out to analyse the devolatilization kinetics of Imperata cylindrica using non-isothermal thermogravimetry (TG) to determine the pre-exponential factors (k0), activation energies (Ea) and fractional contribution. The TGA of Imperata cylindrica was carried out in the temperature range of 30-1,000 °C at four heating rates of 5, 10, 15, and 20 K/min using Nitrogen at a flow rate of 20 mL/min as purge gas. Evaluation of the kinetic parameters involved the numerical regression of the non-isothermal TGA data in MATLAB 2013a based on the pseudocomponent modelling method. The pseudocomponents number used in the modelling was limited between 3 and 10, and the overall quality of fit (QOF) for eight pseudocomponents was found to be the lowest with the value of 1.89 %. The corresponding average values for pre-exponential factor, activation energy and fractional contribution were 791.63 s-1, 12.13 kJ/mol and 0.13. The results proved that pseudocomponent reaction modelling method can be successfully employed to accurately predict the experimental devolatilization rate