A MODIFIED RANDOM PORE MODEL FOR GASIFICATION KINETICS OF COAL CHAR AND BIOMASS CHAR

摘要

Gasification is a well-known reaction owing to its relevance to generation of sustainable energy from biomass. The present paper attempts to experimentally investigate the kinetics of coal char (CC) and biomass char (BC) gasification using carbon dioxide (CO_2) in a controlled environment using Thermo Gravimetric Analyzer (TGA) at different temperature. The random pore model (RPM) and a modified random pore model (MRPM) proposed in this paper were used to investigate gasification kinetics of CC and BC. It was clarified that gasification reactivity of BC is superior to that of CC and gasification reactivity of both chars were improved with increase of temperature, while the influence of temperature on biomass char gasification reactivity is more obvious. Kinetic analysis showed that, since the CC particles were approximately spherical in the shape, the RPM model and the MRPM model could both be used to characterize its gasification process, but flake-like BC gasification process could only be explained by the MRPM. The activation energy for CC and BC using the MRPM are 194.3kJ/mol and 123.3kJ/mol, respectively.