Comparative study on energy efficiency of moving-bed adsorption for carbon dioxide capture by two evaluation methods

Because of the fast heat transfer and the low pressure drop, the technology of moving-bed adsorption for carbon dioxide capture is gathering the momentum in the last decade. The primary aim of this paper is to investigate the influence of various parameters on the energy-efficiency performance of moving-bed adsorption for CO2 capture. The relevant parameters involve desorption temperature, desorption pressure, CO2 capture rate and CO(2 )mole fraction of flue gas. The energy efficiency assessment of moving bed is performed and compared in the light of the minimum separation work and the second-law efficiency. Moreover, two evaluation approaches, which are the thermodynamic carbon pump model and regeneration separation model, are employed and compared as well. Results indicate that the values of minimum separation work for CO(2 )capture by moving bed, which are calculated by regeneration separation model, are about 15% higher than those of thermodynamic carbon pump model under the same conditions. Furthermore, the second-law efficiencies of both models are approximately 10% under the given conditions. It is also found that the regeneration separation model is closer to real status owing to the additional consideration of the adsorption isotherm equilibrium data.

Automated summary

This paper investigates the energy-efficiency performance of moving-bed adsorption for CO2 capture, comparing results from the regeneration separation model and the thermodynamic carbon pump model. The minimum separation work values for CO2 capture by moving bed are found to be approximately 15% higher using the regeneration separation model compared to the thermodynamic carbon pump model. The second-law efficiencies for both models are around 10% under the given conditions, with the regeneration separation model being closer to real status due to the additional consideration of adsorption isotherm equilibrium data.