(263d) Novel Solvent Selection and Solvent Recycling for CO2 Capture In Pulverized Coal Plant

Pulverized coal (PC) plants constitute an important section of the producers of electricity in the United States. However, PC plants significantly contribute to increased emissions of greenhouse gases, principally carbon-dioxide (CO₂).  During recent years, several CO₂ capture strategies have been studied to reduce the environmental impact of these plants. One such technology that has achieved considerable success is the capture of CO₂ by aqueous amine solutions. However, this absorption/stripping technology when used in a PC power plant can reduce the net power output by 20 to 40%. The energy penalty comes from heating up the solution in the stripper, and poses considerable limitations on commercial viability of the process. As a result, various energy-saving modifications have been proposed in the literature ranging from the use of hybrid solvents to novel stripper configurations. In this paper, we show that the energy penalty can be reduced significantly by an appropriate selection of the solvent and the optimization of the capture process operating conditions.  The solvent selection problem has been posed as a Computer Aided Molecular Design (CAMD) problem.  Since most of the amines reacts similarly with CO₂, the focus was on the CO₂ solubility in these new solvents.  These solvents are then evaluated by integrating the CO₂ capture process in the PC plant.  Structure based property estimation techniques are used for process design.  The solvents have shown promising results.  Optimizing these processes shows great reduction in energy, and water consumption, and higher levels of CO₂ capture.