The reaction heat of CO₂ absorption by organic amines is directly related to the regenerative heat consumption of absorbers. Therefore, it is necessary to study and determine the heat of absorption reaction and heat of regeneration reaction of CO₂ capture solvent before its industrial validation and application. According to the law of thermodynamics, a computer model of the heat of absorption reaction and desorption reaction is established and verified. The heat of reaction of the AEP-DPA phase transition absorption system was studied under different ratios, absorption temperatures, reaction concentrations and reaction pressures. The heat of reaction increases with concentration and decreases with pressure. The reaction heat of the AEP-DPA phase transition absorption system and MEA were compared. The optimum reaction conditions were as follows: AEP-DPA ratio 6:4, absorption temperature 40 °C. The reduction rate of absorption heat and regenerative heat of the AEP-DPA phase change absorption system is more than 35% and 31%, respectively.

This study presents a comprehensive overview of a pioneering 1 million-ton carbon capture, utilization, and storage (CCUS) project implemented in the Qilu Petrochemical Shengli Oilfield in China. The project involved a compression-condensation-purification process and aimed to capture CO₂ from the coal gas of the second chemical fertiliser plant of the Qilu Petrochemical Company. Molecular sieves were used to dry the captured CO₂, and MellapakPlus™ structured packing was employed for purification. Two novel energy-saving processes were implemented, a lithium bromide refrigerator unit to recover waste heat for cooling and an expansion generator unit to recover pressure energy from the tail gas. The project layout and land area were carefully determined. The consumption of utilities in the capture system was analysed. Furthermore, an economic assessment of the project was conducted. The technical and economic feasibility of this project was confirmed by the findings. The comprehensive energy consumption per unit of the capture process was 2.649 GJ/t CO₂, the total investment (excluding tax) for CO₂ capture was CNY 380 million (380 CNY/t CO₂), the payback period of the project was 9.20 years, and the sales price (excluding tax) of the project was 194.4 CNY/t CO₂ at a yield of 8%.

The Paris Agreement and one of its goals, “carbon neutrality,” require intensive studies on CO₂ absorption and desorption processes. When searching for ways of reducing the huge energy cost of CO₂ desorption in the amine scrubbing process, the combination of blended amine with solid acid catalysts turned out to be a powerful solution in need of further investigation. In this study, the tri-solvent MEA (monoethanolamine) + EAE(2-(ethylamino)ethanol) + AMP(2-amino-2-methyl-1-propanol) was prepared at: 0.2 + 2 + 2, 0.5 + 2 + 2, 0.3 + 1.5 + 2.5 and 0.2 + 1 + 3 mol/L. The heterogeneous catalytic CO₂ desorptions were tested with five commercial catalysts: blended γ-Al₂O₃/H-ZSM-5, H-beta, H-mordenite, HND-8 and HND-580. Desorption experiments were conducted via a recirculation process with direct heating at 363 K or using temperature programming method having a range of 303–363 K. Then, the average CO₂ desorption rate, heat duty and desorption factors were studied. After comparison, the order of CO₂ desorption performance was found to be HND-8 > HND-580 > H-mordenite > Hβ > blended γ-Al₂O₃/H-ZSM-5 > no catalyst. Among the other combinations, the 0.2 + 1 + 3 mol/L MEA + EAE + AMP with HND-8 had a minimized heat duty (HD) of 589.3 kJ/mol CO₂ and the biggest desorption factor (DF) of 0.0277 × (10⁻³ mol CO₂)³/L² kJ min. This study provided a kind of tri-solvent with catalysts as an energy-efficient solution for CO₂ absorption and desorption in industrial CO₂ capture pilot plants.