Evaluation of high-temperature pyrolysis and CO2 gasification performance of bituminous coal in an entrained flow gasifier

Abstract

This study used an entrained flow gasifier to assess the pyrolysis and gasification performance of Bangladeshi Barapukurian bituminous coal. The pyrolysis and CO2 gasification were conducted at temperatures of 1000°C–1400 °C under atmospheric pressure. The carbon conversion, syngas yield and pollutant emissions of coal using two different particle size of 90–106 and 250–300 μm have been analysed under CO2 concentration of 10–80 vol%. Solid residue (char/ash) was analysed by using scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) methods. Results show that the release of volatile matter increases up to the temperature of 1200 °C. However, the temperature needs to increase at 1400 °C for the complete carbon conversion. Based on the CO/H2 ratio, syngas conditioning is required while using a temperature of 1200 °C or above, especially over the stoichiometric CO2 concentrations. Considering the heating value of syngas for power generation, the use of CO2 should be limited to less than 20% at a temperature of 1200–1400 °C. Particle size is important for carbon conversion but there is no significant impact on the heating value of syngas. Installation of the syngas cleaning system is required to drop the pollutants emission from the ppmv range to the ppbv range.