Gasification reactivity of high ash Indian coals in varying concentrations of CO<SUB align="right">2

Abstract

Optimisation of coal gasification processes requires a good understanding of coal reactivity of the CO2 and steam gasification reactions. Presently there are very few studies on gasification behaviour of high ash coals. Therefore, present paper investigates the gasification behaviour of char samples in 100, 70 and 30% concentrations of CO2 in the temperature range of 900–1050°C using thermogravimetric analyser. Char samples were prepared from high ash Indian coals in inert atmosphere at 800, 900 and 1,000°C. Effects of coal/char properties, char preparation temperatures, char gasification temperatures and varying concentrations of CO2 on gasification reactivity of high ash char samples have been reported. Higher pyrolysis temperature shows adverse effect on CO2 gasification, whereas higher gasification temperature, CO2 concentration, alkali index, surface area as well as porosity favour CO2 gasification reactions. [Received: February 27, 2017; Accepted: December 1, 2017]