Screening Test of Amino Acid Salts for CO₂ Absorption at Flue Gas Temperature in a Membrane Contactor

Abstract

CO2 absorption at the temperature of flue gas inlet could reduce the costs related to flue gas cooling systems and improve the economic feasibility of the postcombustion carbon capture processes. Amino acid salts are considered as promising absorbents to absorb CO2 in a membrane contactor at elevated temperatures because of their advantages of lower volatility, less degradation, and higher surface tension. In this study, 24 common amino acids have been screened for their potential to absorb CO2 at the temperature of flue gas inlet in a membrane contactor. These screening processes involved examination of the water solubility of amino acids, measurement of surface tension and viscosity of their potassium salts, CO2 capacity, and CO2 membrane absorption test. Taurine, sarcosine, and glycine were identified as performing well in all the screening tests and were further investigated for CO2 membrane absorption at high temperatures up to 80 °C and various CO2 loadings in a polypropylene hollow fiber membrane module. The results show that those amino acid salts are feasible to absorb CO2 at high temperatures in a membrane contactor. Potassium sarcosinate is identified as the most promising absorbent for high-temperature CO2 absorption with a better absorption performance than monoethanolamine and other amino acid salts.

Insights into a membrane contactor based demonstration unit for CO2 capture

“…A similar explanation was given by Lu et al [32], who also presented data on the overall mass transfer coefficient as a function of the lean solvent loading using N-methyldiethanolamine as the absorbent. Variation in the absorption flux with the CO2 loading of the lean solution was also reported for various amino acid salt solutions in a screening study by He et al [33].…”

Experimental study on hybrid MS‐CA system for post‐combustion CO2 capture

“…During the chemical absorption process, the liquid mass transfer resistance is dramatically smaller than the gas residence. 46 After the deformation and omission process, Eqn (4) can be converted to Eqn (11), and the mass transfer performance of the packed column evaluated by the overall gas mass transfer constant, K g a e , kmol/ (kpa·m −3 ·h −1 ).…”

“…Original Research Article: Hybrid system for CO 2 capture power plant system can meet the CO 2 removal requirements. In a coal-fired power plant, the methods generally applied for carbon capture are cryogenic distillation, adsorption separation, 9,10 membrane separation, [11][12][13] chemical absorption, 14,15 etc.…”

Kinetics study of CO2 absorption into methyldiethanolamine, potassium lysinate, and their blends in aqueous solution

“…Rahmatmand et al 13 High chemical reactivity, high stability toward oxidative degradation, high surface tension, and low toxicity are advantages of amino acids, which make them a suitable candidate as an additive for tertiary amines. 14 There are 20 common amino acids that can be classified into four different groups including sterically hindered amino acids, cyclic amino acid, poly amino acids, and linear amino acids. 15 These amino acids include valine, serine, lysine, leucine, aspartic acid, asparagine, pipecolic acid, histidine, glycine, arginine, methionine, proline, alanine, sarcosine, glutamic acid, taurine, 6-aminohexanoic acid, 1-aminocyclohexane carboxylic acid, 2-aminoisobutyric acid, 2-piperazinecarboxylic acid.…”

“…High chemical reactivity, high stability toward oxidative degradation, high surface tension, and low toxicity are advantages of amino acids, which make them a suitable candidate as an additive for tertiary amines 14 . There are 20 common amino acids that can be classified into four different groups including sterically hindered amino acids, cyclic amino acid, poly amino acids, and linear amino acids 15 .…”