Effect of partial pressure on CO2 absorption performance in piperazine promoted 2-diethylaminoethanol and 1-dimethylamino-2-propanol aqueous solutions

Piperazine (PZ) was used to enhance the absorption of CO 2 in 2-diethylaminoethanol (DEAE) and 1-dimethylamino-2-propanol (DMA2P) aqueous solutions. The mole fraction of CO 2 in N 2 -balanced gas mixtures ranged from 0.1 to 0.8. The mass fractions of amine and PZ ranged from 0.300 to 0.500 and from 0.050 to 0.075, respectively. The experiments were performed at 313.2 K. The absorption capacity and absorption rate under a series of conditions were illustrated, and the effect of CO 2 partial pressure on the absorption performance was demonstrated. At a given CO 2 partial pressure, the CO 2 absorbed by the PZ promoted DEAE and DMA2P aqueous solutions increases with the mass fraction of the mixed aqueous solutions, and it increases with the CO 2 partial pressure at a given mass fraction. The absorption capacity of the DMA2P-PZ aqueous solution is slightly higher than that of the DEAE-PZ aqueous solution. In addition, the absorption rate depends on the competitive effects of the mass fractions, solution viscosity and the partial pressure of CO 2 .