Waste heat recovery and cascade utilization of CO₂ chemical absorption system based on organic amine method in heating season

In this paper, we proposed a waste heat recovery route of CO₂ chemical absorption systems, which can realize waste heat recovery and cascade utilization in heating season. Simulation methods were used to study carbon capture systems and absorption heat pump, experimental methods were used to study the contact heat transfer characteristics of packed tower, and three organic amine solutions were involved: MEA (2-Aminoethanol), MEA& MDEA (N-Methyldiethanolamine) and AMP (2-Amino-2-methyl-1-propanol). The outlet gas temperature of carbon capture system is 47.7 °C∼58.8 °C, the temperature of lean solution is 73.3 °C∼95.0 °C, the absorption heat pump can increase the return water from 40 °C to 85 °C∼97 °C, the heat transfer end difference between flue gas and water in packed tower can be less than 1.0 °C. The system can achieve energy conservation and CO₂ emission reduction effect, over 80% of the solution waste heat were recovered, the two-stage gas waste heat recovery process can improve boiler efficiency by over 19%.