Investigation of diffusivity and interaction intensities of 2DMA2M1P-based blended sorbents for enhanced CO₂ capture by molecular dynamics simulation

With the development of CO₂ capture technology, blended amine absorbents based on 2-dimethylamino-2-methyl-1-propanol (2DMA2M1P) were designed for effective carbon capture, to overcome the limitations of high desorption energy requirements and the slower absorption kinetics of single amines. Yet the solubility, kinetics and regeneration potential of the mixed amine absorbents still should be carefully investigated. Thus, the present study elucidates the solubility, kinetics and regeneration potential by systematically analyzing inter-intra molecular interaction intensities and estimating CO₂ diffusion rates through molecular dynamics simulation. After studying the 2DMA2M1P based blended solvents with MEA and 3MAP, the radial distribution function analysis results demonstrate that 2DMA2M1P/3MAP blend, having stronger interaction intensities, is expected to enhance CO₂ solubility as compared to 2DMA2M1P and 2DMA2M1P/MEA. In addition, the results pertaining to Mean square displacement show that 2DMA2M1P/3MAP blend also exhibits higher CO₂ diffusivity, leading to higher absorption kinetics. The order of CO₂ diffusion coefficient within the amine system is as follows: 2DMA2M1P/3MAP > 2DMA2M1P/MEA > 2DMA2M1P. In addition, 3MAP showed higher repulsive interaction than that of MEA which shows its lower regeneration energy requirement along with higher kinetics when blended with 2DMA2M1P. These MD simulation data is a step forward towards the development of more effective blended system.