Stripper configurations for CO2 capture by aqueous monoethanolamine and piperazine

AbstractAbsorption/stripping with aqueous amines is a competitive technology for CO2 capture from coal-fired power plants. A major challenge is reducing the energy requirement in the stripper, which has contributions from the reboiler(s), pumps, and compressors. In this study, the effects of flowsheet complexity and solvent choice were explored. Five flowsheets were stimulated in Aspen Plus® using 9 m MEA and 8 m PZ. Although the absorber was not modeled, the rich loadings used for the two solvents accounted for the faster CO2 reaction rate of PZ in the absorber. The simulations demonstrated that increased configuration complexity improved the efficiency of the absorber by 5%–8%, depending on the solvent, operating temperature, and rich loading. The best improvement from the simple stripper was observed with the interheated column. The improvements were attributed to better reversibility of the more complex flowsheets. Furthermore, 8 m PZ consistently had a lower energy requirement than 9 m MEA. Configurations with packed columns exhibited improvements in energy consumption of 9%–11%