Gasification characteristics of Bangladeshi Barapukurian coal in a high-temperature entrained flow gasifier under CO2 atmosphere

Abstract

Coal is the cheapest and reliable source for power generation, which has the potential to reduce the dependency on natural gas, particularly for Bangladesh, where the natural gas reserve is very limited. Despite numerous studies on gasification from different parts of the world, there has not been a research study on gasification characteristics of Bangladeshi Barapukurian coal (BBC) under state of the art entrained flow condition. Thus, this study aims to investigate the gasification characteristics of Barapukurian bituminous coal using a high-temperature electrically heated entrained flow gasifier under atmospheric pressure.The effect of the partial pressure of the gasification reagent (CO2) on carbon conversion and gas yield was tested by varying the volume percentage of CO2 in N2 between the temperatures of 1000-1400°C. Furthermore, the influence of particle size on carbon conversion and product gases was also examined using industrially relevant particle sizes: 90-106 µm and 250-300 µm. The results show that increasing the temperature and feed CO2 concentrations increase the carbon conversion, though the temperature is found to be the dominant factor. A maximum carbon conversion of 92 % was achieved using ultimate operating conditions of 1400°C and 40% CO2 for particles size: 90-106 µm, while the conversion was only 65% for particle size: 250-300 µm under identical operating conditions. Overall, the yield of CO was increased while the yield of H2 was decreased with increasing temperatures and CO2 concentrations. The maximum yield of CO and H2 was determined to be 0.93 and 0.14 L/g coal respectively using particle size: 90-106 µm, which is 0.88 and 0.12 L/g coal using particle size: 250-300 µm at a temperature of 1200°C under 10% CO2. The main pollutants measured were HCN, NH3 and H2S in the ppm range. The results of this study will provide a baseline data for the industrial scale entrained flow gasification of BBC under CO2 atmosphere.Coal is the cheapest and reliable source for power generation, which has the potential to reduce the dependency on natural gas, particularly for Bangladesh, where the natural gas reserve is very limited. Despite numerous studies on gasification from different parts of the world, there has not been a research study on gasification characteristics of Bangladeshi Barapukurian coal (BBC) under state of the art entrained flow condition. Thus, this study aims to investigate the gasification characteristics of Barapukurian bituminous coal using a high-temperature electrically heated entrained flow gasifier under atmospheric pressure.The effect of the partial pressure of the gasification reagent (CO2) on carbon conversion and gas yield was tested by varying the volume percentage of CO2 in N2 between the temperatures of 1000-1400°C. Furthermore, the influence of particle size on carbon conversion and product gases was also examined using industrially relevant particle sizes: 90-106 µm and 250-300 µm. The results s...