The Simultaneous Absorption of Sulfur Dioxide, Chlorine, and MercuryEPA Grant Number: U916148
Title: The Simultaneous Absorption of Sulfur Dioxide, Chlorine, and Mercury
Investigators: Chen, Eric
Institution: The University of Texas at Austin
EPA Project Officer: Lee, Sonja
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $106,759
RFA: STAR Graduate Fellowships (2003) Recipients Lists
Research Category: Fellowship - Other Engineering , Academic Fellowships , Engineering and Environmental Chemistry
The objective of this research project is to successfully demonstrate, on a pilot scale, the use of aqueous piperazine-promoted potassium carbonate for carbon dioxide removal from the flue gas of coal and gas-fired power plants. The technology will be demonstrated on a pilot absorber/stripper system. The absorber and stripper performance will be characterized through the use of different random and structured packing. In addition, the temperature bulge in the absorber column will be profiled, and an economic evaluation for packing selection will be developed.
The experiments on the pilot plant will be conducted using 2.5 m piperazine with 2.5 m potassium carbonate. Preliminary bench-scale experiments have shown that the absorption rate of CO2 is 1.5 to 2.5 times faster than 5.0 M monoethanolamine (MEA), which represents a benchmark for commercial solvents. The heat of absorption also is approximately 25 percent less than MEA. The capacity of this solution is comparable or slightly less than that of 5.0 M MEA. The heat required for stripping will be about 25 percent less than that for MEA. Three major campaigns will be undertaken with the piperazine-promoted potassium carbonate system. During each campaign, the pilot plant will be operated for 4 weeks, 5 days per week, and 24 hours per day. The first campaign will establish the base-case scenario using high surface area random packing. A major portion of Campaign 1 will be devoted to the modification, setup, and troubleshooting of the pilot plant. In the second campaign, another type of random packing will be installed in the stripper. The third campaign will replace the random packing with structured packing in both the absorber and stripper columns. The absorber/stripper system will be operated over a wide range of gas and liquid flow rates. The experimental results will be used to characterize the gas and liquid contact area and liquid film mass transfer coefficients for the different packing.