Solubility of CO 2 in an aqueous blend of diethanolamine and trisodium phosphate

Abstract

This work presents experimental results on the solubility of CO 2 in a new blend of diethanolamine (DEA) and trisodium phosphate (TSP) at temperatures ranging from (303.14 to 333.14) K and partial pressures from (10.133 to 20.265) kPa. Total concentrations of aqueous DEA + TSP blends were taken as (1.0, 1.5, and 2.0) mol·dm -3. In a particular blend, the mole fraction of TSP was in the range 0.02 to 0.20. The results show that CO 2 solubility in a blend with a particular total concentration increases with increasing mole fraction of TSP at fixed temperature and partial pressure of CO 2. The solubility of CO 2 in the blend decreases with increasing temperature but increases with increasing CO 2 partial pressure. The maximum CO 2 solubility in DEA + TSP blends was found to be 0.869 (mol of CO 2)·(mol of absorbent) -1 at 313.14 K, a total concentration of 2.0 mol·dm -3, and a TSP mole fraction of 0.2. The experimental results of the present study are compared with those for other blends available in the literature. © 2011 American Chemical Society.