The Optimization of the Absorbent Formulation and Foam Modification to Enhance CO ₂ Capture Performance

With the increasing demand for low-energy and high-efficiency CO2 capture technologies, traditional monoethanolamine (MEA) absorbents face certain limitations in absorption efficiency and regeneration energy consumption. This paper proposes an MEA mixed amine absorbent and systematically investigates its absorption performance, including absorption efficiency, absorption rate, and absorption capacity. The absorption efficiency, regeneration energy consumption, and regeneration rate of the absorbent are simulated using Aspen Plus V14 simulation software. Simulation results show that, compared with pure MEA adsorbents, the regeneration energy consumption of MEA + NH3·H2O and MEA + 2-amino-2-methyl-1-propanol (AMP) was reduced by 6.42 and 18.27%, respectively, while the regeneration rate was increased by 12.97 and 13.44%. However, the absorption efficiency does not improve. On the basis of this, the addition of the surfactant fatty alcohol polyoxyethylene ether (AEO-9) to the mixed absorbent solution significantly enhances the foaming effect of the absorbent, increasing the gas–liquid contact area and further improving the capture performance. The results show that the absorption efficiency and total absorption capacity of MEA + NH3·H2O absorbent are 94% and 3.01 mol/kg, respectively, which are 39.09 and 22.36% higher than those of traditional pure MEA absorbent (with absorption efficiency of 66.5% and absorption capacity of 2.46 mol/kg). Additionally, the absorption efficiency and absorption capacity of 2-amino-2-methyl-1-propanol (AMP) + MEA absorbent are 97.75% and 3.43 mol/kg, respectively, which represent improvements of 46.99 and 39.43% compared to traditional pure MEA absorbent. Mechanistic studies on the surfactant-containing absorbents, conducted through 13C NMR and Fourier transform infrared (FTIR) spectroscopy, reveal the mechanism of their reaction with CO2. Future research will focus on further optimizing the absorbent formulation and exploring its application potential in industrial CO2 capture systems.