Characterization and analysis of thermal response of rice husk for gasification applications

Abstract

Present study involves characterisation and thermal analysis of rice husk as a potential source for gasification. Both the thermogravimetric (TG) analysis and differential scanning calorimetry were used to study the influence of heating rate on the degradation of rice husk. Experiments were carried out at three different heating rates of 10, 30, and 80 K min−1. The kinetic parameters, viz. pre-exponential factor, activation energy, and order of reaction were evaluated for both first and second reaction zones, which are categorized based on the degradation of cellulose, hemicelluloses, and lignin content present in the biomass. The degradation of mass with temperature obtained from TG curve was validated numerically. The thermal response of rice husk undergoing decomposition has also been modelled by using a one dimensional (1-D) transient thermal model with an nth order approximation for the rate of decomposition. Kinetic parameters, heat of decomposition, and thermal properties are taken as input to the model. The model was validated by measuring the transient temperature profiles during decomposition using Heisler chart at heat transfer coefficient of 20 W/m2 K. The data for specific heat and thermal conductivity of the biomass were taken from the literature and the values of heat of decomposition and kinetic parameters were taken from the experiments. Model results were compared well with the result obtained by using Heisler chart.