Comparison of entrained flow gasification behaviour of Victorian brown coal and biomass

Abstract

This study assesses and compares the gasification performance of a Victorian brown coal (Loy Yang) and Pine bark in the temperature range of 1000–1400°C with CO2 (10–40% in N2) as the gasifying agent in a bench-scale atmospheric entrained flow reactor. The effect of temperature and CO2 concentration in the feed gas on the carbon conversion, syngas composition, and emission of polluting species such as HCN, NH3 and H2S has been investigated. In addition, complementary char analysis such as the particle size distribution and char morphology have been performed in order to characterize the fragmentation behaviour. Further, the mineral matter transformation at elevated temperatures has been analyzed through X-ray diffractograms of the chars and comparing with the thermochemical equilibrium predictions. As expected, the carbon conversion increased with increasing temperature and CO2 concentration. For both the fuels, ∼98% conversion was achieved at 1200°C. The products included the solid residue and the gaseous components such as CO, H2, CO2, and CH4. No tar was observed during the gasification runs. The pollutant gases were in the ppmv range with NH3 and H2S negligible amounts being detected for Loy Yang coal and Pine bark, respectively.