LAUSR

Abstract In order to reduce energy consumption of absorbent regeneration, an amine absorbent piperazine (PZ) was dissolved in an organic solvent N , N -dimethylformamide (DMF) to prepare a phase-changing PZ/DMF solution for CO 2 absorption with solid precipitate of PZ-carbamate. The CO 2 absorption capacity and peak rate of PZ/DMF solution were 22.9% and 29% higher than those of PZ/water solution, respectively. Based on differential scanning calorimetry/thermogravimetry experiments, biscarbamate PZ(CO 2 ) 2 2− and protonation PZ(H) 2 2+ compositions (34.5 wt%) in the PZ-carbamate precipitate mainly decomposed at peak temperature of 91.9 °C due to their instability, and then PZ(CO 2 ) composition (65.5 wt%) in the PZ-carbamate precipitate decomposed at peak temperature of 125.7 °C. The electrochemical corrosion tests and scanning electron microscopy revealed that PZ/DMF solution had much lower corrosivity than PZ/water solution.