To reduce the regeneration costs of capturing CO2 with absorbents, a two-dimensional desorption model for two-phase flow has been proposed. The temperature and pressure predicted by the model were found to agree well with the experiment data. A new synergy pinch concept was proposed to determine the interactive synergy impacts on mass and heat transfer. According to the proposed synergy pinch principle, the carbon surplus (SAC) and energy surplus (SAE) were defined to quantify the synergy effects for mass and heat transfer, respectively. The proposed synergy pinch principle is that the lower the values of SAC and SAE, the more effective the CO2 desorption. In addition, the synergy pinch point can be identified at the ideal value of zero SAC and SAE. Based on this analysis, a stripper with fin internals was introduced that could contribute energy savings of about 10–14% by synergizing the fluid flow between mass and heat transfer. Thus, it was verified that the synergy pinch method can be effectively applied in CO2 emissions control.

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Currently, the most promising amine absorption system for CO capture still faces the challenges of heavy steam consumption and a high energy penalty. Thus, a new thermal-electrochemical co-driven system (TECS) for CO capture was developed to resolve these problems. In the TECS, unknown electrochemical behaviors are quite essential to assess the CO capture performance. Electrochemical experiments were designed using response surface methodology (RSM) to identify electrochemical effects. The results show that the cathode process is slow and difficult, which is the main limitation in improving the performance of the TECS. Forced convection is necessary to improve the diffusion-controlled process and accelerate desorption. Four factors (Cu(ii) molality, CO loading, temperature, KNO molality) play an auxo-action role in determining anode and cathode reaction rates. A regression model is developed based on the experimental data, and optimum operating conditions are obtained. Regeneration energy consumption reaches about 1.3 GJ per t CO, a decline of up to 70% compared with the traditional process. In addition, preliminary CO desorption experiments suggest that the mass transfer ascribed to the electrochemical process accounts for over 50% of the overall mass transfer coefficient in the CO desorption process.

CO 2 capture greatly helps with greenhouse gas mitigation. Chemical and physical absorption can control CO 2 emission, but these methods are costly. To reduce the cost, an efficient solvent mixture of tetramethylammonium hydroxide (TAMH), tetramethylene sulfone (TMS), and ethylene glycol (EG) is assessed. Gas−liquid equilibrium, reaction kinetics, and mass transfer models are developed and validated by experiments. Henry's constant, reaction kinetics, and mass transfer coefficients between CO 2 and TAMH-TMS-EG are identified. CO 2 loading and mass transfer coefficient are, respectively, obtained as 0.55 mol/molTAMH and 4.02kmol/m 2 /s/kPa, which are on average 25% and 34% higher than the typical MEA process. The theoretical energy consumption amount for desorption of TAMH-TMS-EG-CO 2 solutions is identified as 1.11 GJ/t to 1.34GJ/t. Minimum mass transfer resistance is determined at 40% to 80% TMS fraction. A temperature bulge shift and improvement in the interface characteristics enhance mass transfer due to uniform temperature field and good gas and liquid countercurrent contact.