Kinetics Of CO₂ Absorption By Phase-change Absorbents

Carbon capture and sequestration?CCS?is the most direct measure of carbon dioxide emissions in the world today.At present,the alcoholamine method which is widely used in the industry has a problem of high desorption energy consumption.Therefore,research and development of low-cost,low-energy CO₂ capture technology has become the focus of attention.The phase change absorption method has a phase separation phenomenon of the absorbent-absorbent product in the absorption process,and only the absorption product is sent to the stripping plate for regeneration,and the absorbent can be directly reused,so the required solvent regeneration energy consumption is greatly reduced,and it is considered It is an ideal alternative to alcoholamine absorption.The wet wall column was used as the reaction device to explore the kinetics of CO₂ absorption.The experimental results were read by the best experimental ratio by the experimental scheme of DETA/PMDETA/sulfolane.Sulfolane is an excellent solvent due to its high thermal stability and stability to acids and bases.In this paper,DETA/PMDETA/sulfolane is used to absorb carbon dioxide as an absorbent,and phase separation and CO₂ capacity are carefully studied by titration and NMR.It was analyzed by NMR.Compared with a single MEA,the energy consumption of the mixed amine solution was relatively low.Further analysis was performed to determine the regenerative energy required.Provide a theoretical basis for the development of new CO₂ absorption methods.In this study,DETA/PMDETA/sulfolane phase change solvent has the characteristics of high CO2 absorption rate,fast absorption rate and low energy.After absorption of CO₂,the solution is split into an upper layer containing PMDETA/sulfolane and a lower layer of CO₂-rich DETA/PMDETA/sulfolane.Due to the strong affinity between sulfolane and carbon dioxide,the absorption rate is increased by a factor of 0.7.With the increase of CO₂ loading or gas flow rate,the total mass transfer coefficient is controlled by gas film mass transfer control to liquid film mass transfer control.Since only the CO₂-rich phase was sent to the stripper for regeneration,we calculated the regeneration heat of DETA/PMDETA/sulfolane.Compared with 5M MEA,the sensible heat and vaporization heat of DETA/PMDETA/sulfolane decreased by 49.4%and 80.1%,respectively its total regenerative energy consumption is 2.48GJ/t-CO₂.Significantly lower than the traditional MEA process?3.85 GJ/t-CO₂?.