ABSORPTION OF SO2 INTO TRIBASIC SODIUM-CITRATE SOLUTIONS

Experiments have been carried out on the absorption of SO2 into 1 M solutions of tribasic sodium citrate in the temperature range 20-50-degrees-C. A global mass-transfer coefficient that remains constant during the absorption process has been defined on the basis of the total SO2 concentrations. A procedure has been developed for calculating the concentrations of the species involved in the absorption process. This is based on the assumption that the equilibria occur instantaneously, which allows a buffer capacity of 0.68 to be established regardless of temperature. It also allows the mass-transfer enhancement factor and, thus, the physical absorption coefficient, to be determined. In addition, a saline-effect parameter of -0.043 (regardless of temperature) was calculated using the equilibrium data.