Determination of Char-CO₂ Gasification Rate through Reaction Product

Abstract

This paper presents gasification kinetic parameters generated for Japanese lignite coal char reacting with carbon dioxide and the method for obtaining them. The experiments were conducted in a PTGA at atmospheric pressure within a temperature range of 1148K-1223K, and a mass spectrometer (MS) is coupled with PTGA to obtain the concentrations of product gas. The experiments were carried out with isothermal method, and kinetic parameters were determined through the analysis of the weight changes of coal char and the concentrations of products respectively. The effect of CO2 partial pressure on reaction rate was analyzed by nth order rate equation. It was found that the activation energy of char-CO2 reaction obtained from weight loss curve and product concentrations were 187.9kJ/mol and 187.0kJ/mol respectively, and the reaction order n were 0.24 and 0.222, proving MS a feasible method for kinetics research. Through the comparison, the method to obtain the kinetic data by concentrations of gas products was determined, and a more clear understanding of the gasification process was established.