Amino Acid Based Solvent Vs. Traditional Amine Solvent: a Comparison

Abstract

There is an increase in the development of absorption of acid gases by chemical solvents from flue gases of power plants due to the growing attention paid to the capture and storage of CO2. With the aim of substituting traditional amines, which at present have many disadvantages such as high energy requirement, corrosion, and toxicity, innovative solvents are being studied. In the last few years, attention has been paid to solvents which form precipitate during the absorption phase. Amino acids belong to this category and, because of their characteristics, allow a further enhancement of the chemical absorption process. Thus, it is possible to perform the removal of CO2 in an amount similar to that of traditional amines, but with lower regeneration energy and costs. In this work, an amino acid solvent of potassium taurate solution (4M potassium hydroxide – 4M taurine) has been considered. The process has been simulated with the commercial software ASPEN Plus® to perform a rigorous calculation. The software had been user customized on the basis of the available experimental data in previous work. Our previous publications reported the modelling of the process and the evaluation of its performance applied to the purification of a flue gas stream. In this work, a techno-economic comparison between the amine scrubbing process and the potassium taurate process is presented, taking into account both the operating costs, mainly affected by the energy consumption, and the capital costs.