Sustainability assessment of the oxy-combustion coal-fired power plant using low-grade fuel

Abstract

In line with global efforts to reduce emissions, the integration of coal-fired power generation plants with carbon capture technologies has been investigated. Low-rank coal is gaining interest as coal price is on an increasing trend in recent years, however, an air-combustion of low-rank coal without CO2 capture shows a high specific CO2 emission of 869 kgCO2/MWh. This work presents a comparative assessment of post-combustion CO2 capture and oxy-combustion retrofitted to a low-rank coal-based power plant from the viewpoints of economics and sustainability. Post-combustion CO2 capture leads to an 82.7 % reduction in the specific CO2 emission (of 151 kgCO2/MWh) with a CO2 avoidance cost of 47.5 USD/tonCO2. Oxy-combustion is shown to be more competitive for CO2 capture applications, achieving a 97.3 % reduction in the specific CO2 emission (of 23.8 kgCO2/MWh) with a CO2 avoidance cost of 37.7 USD/tonCO2. As results of sensitivity analysis, the low-rank coal-based oxy-combustion power plant is more economically and environmentally attractive.