Abstract:

In order to solve the problems of high regeneration energy consumption and poor recycling rate in the CO₂ capture process of traditional absorbents, the research and development of new high-efficiency and low-energy-consumption solvents has become the focus of current research. In this experiment, diethylene triamine (DETA) was used as the main absorbent, and triethanolamine (TEA) was used as the auxiliary absorbent. The mixture was mixed according to different proportions with total amine concentration of 30%. Taking the traditional absorbent 30% monoethanolamine (MEA) as the reference standard, the CO₂ absorption-desorption performance, desorption energy consumption and viscosity were tested, the optimal ratio of DETA+TEA absorption was selected. The experimental results found that when the proportions was DETA+TEA= 20%+10%, the solution not only has highly CO₂ absorption capacity, but also has the excellent regeneration performance and low desorption energy consumption. The saturated uptake of the absorbent is 3.71 mol CO₂/L solvent, the maximum desorption rate is 1.94 mmol/(L?min), and the desorption energy consumption is 160 kJ/mol. Compared with the 30% MEA absorbent, the saturated uptake was increased by 34.42%, the maximum desorption rate was increased by 170%, and the energy consumption was reduced by 21.2%. The stability of 20 cycles is as high as 98%, and the viscosity of the absorbent is 3.1-6.88 mPa·s.

Key words: CO₂ capture, mixed amine absorent, absorption, desoription, energy consumption, viscosity