Reactivity Study on the Kideco Coal Catalytic Coal Gasification under CO₂Atmosphere Using Gas-Solid Kinetic Models

Abstract

주제어 : 저등급석탄, 석탄 가스화, 촉매, 이산화탄소, 활성화에너지 Abstract : In this study, we have investigated the kinetics on the char-CO2 catalytic gasification reaction. Thermogravimetric analysis (TGA) experiments were carried out for char-CO2 catalytic gasification of an Indonesian Kideco sub-bituminous. Na2CO3 and K2CO3 were selected as catalysts which were physically mixed with coal. The char-CO2 catalytic gasification reaction showed a rapid increase of carbon conversion rate at 850 ℃, 60 vol% CO2, and 7 wt% Na2CO3. At the isothermal conditions ranging from 750 ℃ to 900 ℃, the carbon conversion rates increased as the temperature increased. Four kinetic models for gas-solid reaction including the shrinking core model (SCM), random pore model (RPM), volumetric reaction model (VRM), and modified volumetric reaction model (MVRM) were applied to the experimental data against the measured kinetic data. The gasification kinetics were suitably described by the MVRM for the Kideco sub-bituminous. The activation energies for each char mixed with Na2CO3 and K2CO3 were found 55-71 kJ/mol and 69-87 kJ/mol.