Evaluation of energetic benefit for solid-liquid phase change CO2 absorbents

Abstract

A preliminary evaluation of desorption energy requirement for a precipitating system shows that precipitate formation results to a decrease in desorption energy requirement for a precipitating amino acid salt system compared to a non-precipitating one. Based on a conventional absorber-stripper configuration, only a marginal benefit may be achieved for a precipitating 5m’ KSAR compared to a 30wt% MEA system. Vapour liquid solid equilibrium measurement was carried out for a newly selected precipitating system at 40 and 120 °C. This precipitating system has good absorption rate and is able to precipitate earlier in the absorption process. The measured equilibrium CO2 partial pressure shows good temperature sensitivity and thus good potential for a significant reduction in desorption energy requirement. The cyclic capacity of this system at 10 kPa CO2 partial pressure is found to be higher than that of 30wt% MEA by 61% and by 39% for a precipitating 5m’ KSAR system.