Development and testing of a new post-combustion CO2 capture solvent in pilot and demonstration plant

Abstract

Post-combustion CO2 capture for coal-fired power plants is an important technical option to mitigate greenhouse gas emission from coal-based power generation. CO2 capture based on chemical absorption is currently the dominant technology for large-scale capture unit. The main obstacle of commercial application is the high cost and high energy consumption, innovation of new absorption solvent is one of the keys to the performance improvement. Based on the characteristics of flue gas, combined with the analysis and comparison of potential amine components, the formula of blended amines are developed, which is further screened by true-heat flux calorimetric test combined with vapor-liquid equilibrium test, HNC-5 is selected through the lab test, because of its lower heat of absorption and higher capture performance. The test on a 1000 t/a CO2 capture pilot plant under real flue gas conditions shows that the performance index of HNC-5 is consistent with the lab test results. The CO2 capture ratio is higher than 90%, and the heat consumption during regeneration is reduced by about 20% compared with MEA. The continuous operation results of the 120,000-ton/year CO2 capture unit show that heat duty of regeneration of HNC-5 is about 2.8GJ/tCO2, the cost per ton of CO2 captured is reduced by about 63 CNY, the usage life is longer, helping improve the system availability and reliability.