Simulation and Performance Comparison for CO 2 Capture by Aqueous Solvents of N -(2-Hydroxyethyl) Piperazine and Another Five Single Amines.

Li, Simeng; Li, Han; Yu, Yanmei; Chen, Jian

N-(2-Hydroxyethyl) piperazine (HEPZ) has a chemical structure similar to PZ and has less volatility. It is not easy to volatilize in a continuous operation device. It is studied to replace PZ as a promotor to increase the CO2 capture rate. This paper researches the lowest energy consumption and absorbent loss of HEPZ/H2O in the absorption-regeneration process, and compares it with another five amines, including PZ, MEA, 1-MPZ, AMP and DMEA. Based on the thermodynamic model, this work establishes a process simulation based on the equilibrium stage, assuming that all stages of the absorption and desorption towers reach thermodynamic equilibrium and CO2 recovery in the absorption tower is 90%. By optimizing the process parameters, the lowest thermodynamic energy consumption and absorbent loss of process operation are obtained. Our results show that HEPZ as a promotor to replace PZ and MEA has significant economic value. The lowest reboiler energy consumption of HEPZ with the optimal process parameters is 3.018 GJ/tCO2, which is about 35.2% lower than that of PZ and about 11.6% lower than that of MEA, and HEPZ has the lowest solvent loss. The cyclic capacity is 64.7% higher than PZ and 21.6% lower than primary amine MEA.

CARBON dioxide; SOLVENTS; AMINES; ENERGY consumption; THERMODYNAMIC equilibrium; PIPERAZINE

Processes, 2021, Vol 9, Issue 12, p2184

2227-9717

Academic Journal

10.3390/pr9122184