Characterisation and double parallel random pore model fitting kinetic analysis of faulty coal oxygen-enriched co-combustion

Abstract

This study used various analytical techniques to explore the structural characteristics of anthracite, lean coal, and bituminous coal. Thermogravimetric analysis assessed the combustion performance of individual coals and their blends. Results revealed distinct structural differences among the three coals. Although lean coal's functional groups distribution resembled bituminous coal, its carbon ordering aligned with anthracite. Increasing the proportion of bituminous coal minimally improved combustion in air. Under O2 + N2, rising oxygen levels lowered ignition and burnout temperatures, enhancing the comprehensive combustion index. At high heating rates, 30 %O2 + 70 %CO2 outperformed 30 %O2 + 70 %N2. The fitting performance of the double parallel random pore model (DRPM) was superior to that of the random pore model (RPM). Kinetic analysis suggested a DRPM for lean coal and bituminous coal co-combustion, unfolding in two stages. Activation energy increased with O2 concentration in O2 + N2 but remained lower than in O2 + CO2.