Theoretical Investigations of the Effects of Isothermal and Non-isothermal Heating Conditions on the Pyrolysis Kinetics of Biomass Particle

Abstract

There has been a growing interest in renewable energy sources from various part of the world over the past decades. One of the promising alternatives to fossil fuels is biomass and in all the common technologies of its conversion, pyrolysis is present atleast as a first stage of the conversion process. As part of the scientific studies and understanding of this very important process in the thermochemical conversion of the solid fuel, the development of good mathematical models which in consequent leads to the design of pyrolysis reactors and biomass gasifiers is paramount. However, due to the complexities of the biomass reaction scheme, the pyrolysis of biomass is generally modeled on the basis of apparent kinetics. Moreover, most of the past works were based on the overall pyrolysis kinetics, and studies concerning pyrolysis products are much less common. Therefore, this work presents the analytical solutions of the kinetics of pyrolysis of biomass particle under non-isothermal and isothermal heating conditions. The developed models were used to investigate the effects of heating conditions and heating rates on the pyrolysis of wood products. The comparison of the simulated results with the available results reported in literatures show good agreements were found. This work could be used in predetermining the biomass products concentrations under different heating conditions and the estimating the optimum parameters in the pyrolysis of biomass and in the design of some pyrolysis reactors/units.Keywords: Biomass particle; Pyrolysis; Kinetics; Analytical solutions; Isothermal temperature and NonIsothermal heating rates Nomeclature A1; A2; A3; A4; A5 frequency factor, 1/s C concentration, kg/m 3 E activation energy, J/mol