Research Group Website

Presentation for Prospective Graduate Students

Educational Qualifications

Ph.D., Chemical Engineering, University of California, Berkeley (1977)
M.S./B.S., Chemical Engineering, Massachusetts Institute of Technology (1971)
UT Separations Research Program

Focus

Control of air pollution by acid gases, carbon dioxide, and air toxics, CO2 capture, flue gas desulfurization, acid gas treating, CO2 mass transfer with chemical reaction, electrolyte thermodynamics, reaction kinetics in aqueous solutions.

Research

We are developing a fundamental understanding of the kinetic and mass transfer phenomena in aqueous technologies for air pollution control and acid gas treating. Limestone slurry scrubbing is the dominant technology for sulfur dioxide removal.

Limestone slurry and other aqueous solutions may also be effective for removal of mercury from waste gases.

We are quantifying the absorption of mercury as a function of solution composition in a highly characterized wetted wall contactor. The results are interpreted with the theory of mass transfer with fast reaction in the boundary layer.

Our group is quantifying the thermodynamic and kinetic phenomena in technologies for removing hydrogen sulfide and carbon dioxide by absorption/stripping with alkanolamine solutions. This technology has grown in importance with new amine alternatives and increased interest in marginal natural-gas resources and CO2 capture from flue gas. We are developing a comprehensive model with a rigorous representation of excess Gibbs energy that is able to simulate simultaneously vapor-liquid equilibria, heats of reaction, freezing point depression and other thermodynamic data.

Acid-gas absorption into alkanolamine solutions occurs by mass transfer with chemical reaction. We are measuring the absorption rates of the acid gases as a function of gas and solution composition for common and innovative amines. Parameters representing reaction kinetics, diffusion coefficients, and equilibria are extracted from the experimental data. The available data and models of equilibria and mass transfer are integrated into a rate-based simulation of the absorption/stripping process. The model must simultaneously account for the complex equilibria and rate processes while converging heat and material balances at every point in the absorber and stripper. Innovative solvents that we develop for CO2 capture are being tested in a pilot scale facility on the Pickle Research Campus. These results will validate the integrated models of absorber/stripper performance and demonstrate innovative process concepts.

Selected Publications

• “A Thermodynamic Model of Methyldiethanolamine-CO2— H2S— Water”, Ind. Eng. Chem. Res., 36, 3944-3953 (1997) (with M. Posey).
• “Hg Absorption in Aqueous Oxidants Catalyzed by Hg (II),” Ind. Eng. Chem. Res., 37, 380-387, 1998 (with L. Zhao).
• “Research Needs for CO2 Capture from Flue Gas by Aqueous Absorption/Stripping,” Final report on DOE P.O. No. DE-AF26-99FT01029, January 17, 2001 (with. S. Bishnoi, S. Chi, H. Dang, and J. Santos)
• “Oxidative Degradation of Monoethanolamine.” Revised for Ind. Eng. Chem. Res., May 2002. (with S. Chi).
• “Rate-Based Modeling of Reactive Absorption of CO2 and H2S into Aqueous Methyldiethanolamine,” Ind. Eng. Chem. Res., 37(10), 4107-4117 (1998) (with M. Pacheco).
• “Absorption of Carbon Dioxide into Aqueous Piperazine: Reaction Kinetics, Mass Transfer and Solubility,” Chem. Eng. Sci., 55 (2000) 5531-5543 (with s. Bishnoi).
• S. Bishnoi/G.T. Rochelle, “Thermodynamics of piperazine/methyldiethanolamine/water/carbon dioxide,” IECR; 2002; 41(3); 604-612 (with S. Bishnoi).
• “Hg Absorption in Aqueous Hypochlorite,” Chem. Eng. Sci., 54, 655-662 (1999) (with L.B. Zhao).