Effect of Model and Operating Parameters on Air Gasification of Char

Char is one of the major products of solid-fuel pyrolysis. It is lightweight and yet retains a substantial proportion of the original thermal energy. Gasification of char provides cleaner energy compared to its original fuel for both domestic heating and electricity production. The effect of the thermal as well as chemical parameters on the char gasification process, however, has not yet been fully investigated. In this paper, mathematical models are employed to simulate the char gasification process in a fixed bed and model parameters are varied to assess the subsequent effect on the characteristics of fixed-bed char gasification. A series of benchtop experiments were carried out to validate the theoretical simulation. It is found that the gasification processes is affected by not only the reaction kinetics but also the heat and mass transfer between the gas and solid phases and correct model parameters are critical for the prediction of gasification performance, especially the gas compositions.