Amino acid salts for CO2 capture at flue gas temperatures

•To develop novel absorbents for CO2 capture at high temperatures.•To determine the physical properties of the novel absorbents at high temperatures.•To determine the CO2 solubility of the novel absorbents at high temperatures.•To investigate the CO2 kinetics of the novel absorbents at high temperatures.•To model the absorption reaction rate of the novel absorbent at high temperatures.

The amino acid salt potassium taurate has potential for use as a high-temperature absorbent for post-combustion CO2 capture, because of its low volatility and high absorption rate. In this study, the densities and viscosities of 2–6 M taurate solution were determined over the temperature range of 293–353 K. We found that the CO2 solubility of taurate solutions, measured using a stirred-cell reactor, is comparable to that of alkanolamines at high temperatures. The absorption rate of CO2 into CO2-free and CO2-loaded taurate solutions was determined using a wetted-wall column. The KG of 4 M taurate at 353 K is similar in magnitude to the KG of 7 m monoethanolamine (MEA) at 313 K. We also found that the KG of taurate decreased with increased CO2 loading, although the KG values of taurate solutions are still comparable to CO2-loaded 7 m MEA solution. The reaction rate constant of taurate carbamate formation in this work agrees well with published values.