Removal of acid gases from natural and flue gases by aqueous alkanolamines has become a well-established process. Recently, prostate there is great interest in the development of more efficient processes to recover carbon dioxide, a greenhouse gas. This interest coincides with the exploitation of poorer quality crude oil and natural gas and the development of new enhanced oil recovery projects using CO2 as a flooding agent.
Economical and efficient process design requires accurate fundamental data values such as the solubility, physical and transport properties, and heat of absorption and kinetic rate data. The fundamental understanding of acid gas treating processes requires the utilization of electrolyte thermodynamics, mass transfer with chemical reaction in nonideal systems, theories for gas absorption into a turbulent liquid phase, various numerical methods for solving the equilibrium rate equations, and nonlinear parameter estimation of kinetic and thermodynamic parameters (Glasscok, 1990). With the recent advent of mass transfer rate-based computer models, a need has been created for reliable experimental data on diffusion coefficients and reaction rates.
In order to measure kinetic rates and diffusion coefficient as well as the solubility, a quiescent surface stirred-cell reactor was built. The reactor has an externally driven and magnetically-coupled stirrer. It is also equipped with a digital pressure gauge and data acquisition software in order to measure the pressure variation with time. The reactor can be operated up to a pressure of 60 psi and 120 °C.
The current study deals with the measurement of the rate of reaction of carbon dioxide in aqueous blends of novel and classical alkanolamines (TEA, MDEA, AMP, DGA, DIPA, 2-PE, TREA, DEMEA, DMMEA and others) and physical solvents (TTEGDME, NFM, sulfolane and others) and aqueous mixed solvents. The objective is to obtain the kinetic rate constants of the reaction and diffusion coefficients and to propose new rigorous models to correlate the data obtained. Research is underway to find a new fast reacting tertiary or hindered amine.