The thermodynamic properties of aqueous solutions of physical and chemical solvents are essential in understanding a great variety of problems ranging from the heat of regeneration to corrosion phenomena in the plant. Particularly important is knowledge of the temperature and pressure dependence of the main thermodynamic functions.
Natural gas or flue gases purification requires the removal of acidic impurities, site carbon dioxide and hydrogen sulphide. The removal process of these acid gases requires the knowledge the solubility of the gases in the solvent and the enthalpy of absorption and desorption of the gases in the solvent.

Experimental data can be used to calculate the temperature variation of the solubilities, activity coefficients and reaction constants. In addition, heat transfer and energy balances on the absorption and regeneration units require the measurement of the heat capacity of the solvents and their thermal conductivity.

The calorimeter used in this study is a C 80, a high-performance Calvet type calorimeter manufactured by Setaram (Lyon, France). The instrument allows a very large range of applications in various fields to be performed. The instrument can be operated from ambient temperature to 300 °C and up to a pressure of 100 bars. It is equipped with a reversing mechanism and mixing vessels with membranes, liquid heat capacity cells. The calorimeter is equipped a with state of the art software for data collection and processing.

The calorimeter is used to measure the heat of solution of carbon dioxide in physical solvents (TTEGDME), the heat capacity of aqueous solutions of alkanolamines and mixed solvents. Enthalpy data for mixing of water and other solvents are important to the understanding of the variation in molecular interaction between molecules. It will also be used to measure the heat of reaction of carbon dioxide with various alkanolamines and amine blends. There is a great need for new calorimetric data for a variety of systems of interest.