Performance study on mixed solvent for post-combustion carbon capture using rotating packed bed technology

Modeling of CO₂ removal in a rotating packed bed using a mixed amine solution of piperazine and methyldiethanolamine with various molar concentration ratios was done with Aspen Plus^® and dynamically linked with Intel^® Visual Fortran. In addition to the mass and energy balances, all the necessary correlations for the rotating packed bed were written in Intel^® Visual Fortran. The developed model was validated, and the result showed good agreement with a percentage error of less than 10%. The model was scaled-up to absorb CO₂ from the flue gas composition of a typical 6.4 MWe biomass power plant with the goal of producing net negative CO₂ emissions. The effect of process parameters such as temperature, rotation speed, liquid-gas ratio, methyl diethanolamine concentration, and piperazine concentration on capture efficiency and regeneration energy was investigated. It was discovered that increasing the rotational speed results in an improvement in the separation efficiency. Increasing the temperature of the lean solvent causes a decrease in separation efficiency, which is due to a decrease in solubility as the temperature increases. Increasing the liquid-to-gas ratio leads to an increase in CO₂ absorption efficiency because more hydroxide ions are present to react with the CO₂. Piperazine is a reactive compound and increasing its concentration in the mixed solvent leads to an increase in CO₂ absorption efficiency. Finally, the results of the study demonstrated that a solvent mixture consisting of piperazine and methyldiethanolamine has the potential to be utilized in post-combustion CO₂ capture using rotating packed bed technology. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.