A comprehensive numerical model coupled two correlative one-dimensional unsteady heat conduction equations of spherical particle with distributed activation energy model has been developed for heat and mass transfer mechanism in lignite pyrolysis with solid heat carrier. The finite volume method and the genetic algorithm optimization toolbox based on Matlab software were employed to calculate the thermal and dynamic parameters

separately

and the reliability of the predictions was further validated by thermogravimetric data of the Hulunbuir lignite and temperature measuring experiment on a laboratory-scale fixed bed reactor

respectively. It was found that the variations in mass and heat transfer during lignite pyrolysis with solid heat carrier showed a complex coupling characteristic. The time-dependent rules of temperature field in radial direction have been obtained by varying operation conditions

such as coal particle radius

the initial temperature and feed amount of solid heat carrier. Besides

the relationship between the releasing rate of pyrolytic products and temperature field revealed that the change of temperature field with heating time in lignite pyrolysis was the primary cause of different distribution of the pyrolytic products.