Effect of Char Preparation Conditions on Gasification in a Carbon Dioxide Atmosphere

Abstract

Pyrolysis conditions have a substantial impact on the properties of the resulting char and, consequently, on the kinetics of the gasification process. The aim of this study was to determine the impact of coal pyrolysis on the gasification stage. By applying the thermogravimetric method, kinetic analyses of CO2 gasification of chars derived from Polish “Janina” coal were conducted. Gasification examinations were performed for chars prepared earlier in an argon atmosphere at various heating rates, which, after cooling, were subjected to CO2 gasification (indirect char gasification). Examinations were also carried out in the case of chars formed during heating of coal samples in a CO2 atmosphere (direct char gasification). Samples of chars were gasified in non-isothermal conditions of up to 1100 °C under 0.1 MPa pressure at various heating rates. The char gasification reaction order with CO2 was determined with the use of the Coats–Redfern method, and it can be assumed that it is a first-order reaction. The ...