The simplified Clegg-Pitzer equations are used to correlate the solubility data of CO2 in the 2-PE (2-piperidineethanol) (45 wt %)-TMS (sulfolane) (40 wt %)-H2O (15 wt %) system at 25, 40, 70, 100, and 130 degrees C and the solubility data of H2S in the 2-PE (45 and 55 wt %)-TMS (40 and 10 wt %)-H2O (15 and 35 wt %) systems at 40 and 100 degrees C. The interaction parameters thus determined can be used to predict the solubility data for the CO2-2-PE (55 wt %)-TMS (10 wt %)-H2O (35 wt %) system at 40 and 100 degrees C and also for the quinary CO2-H2S-2-PE-TMS-H2O system without any additional adjustable parameters. The equations have been proven again to be of use for aqueous solutions containing mixed physical and chemical solvents and ionic species with chemical equilibria.