Abstract

The enthalpies of solution, H^S, of carbon dioxide in aqueous methyldiethanolamine were measured with an isothermal flow calorimeter over wide ranges of temperature, pressure, weight percent MDEA, and loading (gmole CO₂/gmole MDEA). The values of H^S (kJ/gmole CO₂) were found to be constant up to the saturation concentration of CO₂ in the aqueous solution. In addition, experimental data showed that H^S was independent of the total pressure over the solution, but linearly dependent upon both temperature and weight percent MDEA as was given by a correlation. A computer program based upon basic thermodynamic quantities was developed to model H^S of CO₂ in MDEA solutions. The values of K and ΔH for each of the chemical reactions (except the MDEA protonation reaction) were fitted values from the literature. Activity coefficient correlations used in the program were also obtained from the literature. Using these data, the program was first used to find the values of K and ΔH for the MDEA protonation reaction which gave the minimum error between the model and the experimental data. Finally, the values of H^S predicted by the program were compared to the experimental data and the differences were discussed.

Degree

College and Department

Ira A. Fulton College of Engineering and Technology; Chemical Engineering

Rights

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