Achieving Zero/Negative-Emissions Coal-Fired Power Plants Using Amine-Based Postcombustion CO₂ Capture Technology and Biomass Cocombustion

The strengthening carbon mitigation efforts to meet the 1.5 °C target requires the development of zero/negative CO₂ emission technologies to eliminate large direct CO₂ emissions from fossil-fuel fired power stations. Amine scrubbing is a dominant technology to capture CO₂ from fossil-fuel power stations, but its application in achieving zero/negative emission in power stations is rarely reported. The present study investigates the MEA-based technologies to achieve zero and negative CO₂ emission in coal-fired power stations, and their techno-economic performance was evaluated in detail. These zero/negative-emission technologies include 99.7% CO₂ capture from flue gas (zero emission), biomass cocombustion with coal integrated with CO₂ capture at ratios of 10% biomass/90% CO₂ capture and 5% biomass/95% CO₂ capture (zero-emission), and 10% biomass/95% CO₂ capture for negative-emission power station. Our investigation revealed that these zero/negative-emission technologies are technically and economically viable, and their CO₂ avoided costs did not significantly increase compared to the standard 90% CO₂ capture. The CO₂ avoided cost for 99.7%-capture is estimated at $66.5/tonne CO₂, which is $2.6/tonne CO₂ higher than that of 90%-capture. The biomass cocombustion zero/negative-emission technologies show better economic performance with CO₂ avoided cost of $64.1-64.8/tonne CO₂, which is only $0.2-0.7/tonne CO₂ higher than the standard 90%-capture. These results indicate that the amine-based CO₂ capture integrated with biomass cocombustion technology would be economically competitive to achieve zero or even negative CO₂ emissions in coal-fired power stations.