Study On Absorption And Desorption Characteristics Of CO₂ Capture By AEP/BUMEA-alcohol Solution

At present,large-scale reduction of carbon dioxide（CO₂）emissions is a major technical requirement for China to achieve carbon emissions peak and carbon neutrality.The chemical absorption based on alcohol amine solution is the most mature technology for carbon dioxide emission reduction from flue gas of coal-fired power plants.The extensive energy penalty during the regeneration process is a crucial challenge facing industrial application of traditional water-based amine systems for CO₂ capture.Hence,the development of high-efficiency and energy-saving CO₂absorbents becomes the core issue and key technology for the large-scale industrial application of CO₂ capture.Aiming at the above defects of conventional amine aqueous solution in CO₂capture,new non-aqueous absorbents were proposed by blending N-aminoethylpiperazine（AEP）and 2-butylaminoethanol（BUMEA）with ethylene glycol（EG）,n-butanol（NBA）and 2-ethoxyethanol（2EE）.In order to investigate the CO₂ capture capacity of amine-alcohol solutions,an absorption-desorption experimental platform was designed and built in this paper.The CO₂ absorption capacity and apparent CO₂ absorption rate of AEP/BUMEA-alcohol system with different mass fraction were measured in the CO₂ absorption experiment,and the BUMEA-alcohol solutions with good absorption perfomance were screened out.The pseudo-first-order reaction rate was calculated based on Lagergren kineticmodel.The key reaction intermediates,compositions of removal products and reaction pathways were demonstrated on the basis of experiments and characterization analysis(¹³C Nuclear Magnetic Resonance)for illustrating the mechanism of CO₂ capture by novel solvent.The desorption capacity and apparent desorption rates of different mass fraction BUMEA-alcohol systems were measured,and three optimal ratios were determined for cyclic absorption-desorption to verify the stability of the cycle.The results showed that BUMEA-NBA solutions had high absorption and desorption rates,great circulation stability,and the maximum CO₂ absorption was slightly higher than 30wt%MEA aqueous solution.Therefore,it could provide a reference for the study of amine-alcohol absorbent,and had certain practical application prospects.The research results of this paper can provide theoretical basis and technical support for the development of efficient and low-cost CO₂ capture.