CO2-Binding Organic Liquids (CO2BOLs) chemically react with CO2 in analogy to aqueous amines, albeit without water. CO2BOLs have a distinctive change in polarity of the sorbent in the CO2-lean and CO2-rich forms. This reversible gradient shift in polarity is dictated by the loading of CO2 in the BOL, and thus, changes in the bulk polarity of the BOL influence CO2 loadings. Exploitation of this polarity change can aid in the regeneration of CO2BOL solvents, in which we introduce a �polarity-swing-assisted regeneration (PSAR)� Conceptually, the PSAR is simply an injection of a metered amount of chemically inert non-polar �anti-solvent� to the CO2-rich form of the CO2BOL in combination with heating. After CO2 is released from the CO2BOL, solution is cooled below its critical miscibility temperature and the anti-solvent is separated from the now CO2-lean CO2BOL. Experimental data and process analysis suggest the PSAR can reduce the regeneration temperatures of CO2BOL solvents by as much as 72 �C by shifting the free energy of the reaction between CO2 and the BOL. Lower regeneration temperatures in a PSAR compared to a thermal cycle only allows for reduced thermal degradation and lower fugitive emissions of the CO2BOL solvent. Furthermore, lower reboiler temperatures allow for significant efficiency gains from the steam cycle of a power plant. Process simulations project that a PSAR could increase performance of sub-critical coal fired plants with a lower parasitic power compared to DOE's case 10 baseline when operating the PSAR at full strength. We describe in detail, all aspects of the PSAR process ranging from concept, laboratory data, through thermodynamic modeling and process simulations. We present here VLE and LLE evidence of the polarity's impacts on the CO2BOL performance, preliminary thermodynamic models of the PSAR, followed by net power outputs calculations derived from Aspen plus simulations of the PSAR process.

Improving the regeneration of CO<sub>2</sub>-binding organic liquids with a polarity change

246th National Meeting (2013)

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Improving the regeneration of CO2-binding organic liquids with a polarity change

Improving the regeneration of CO₂-binding organic liquids with a polarity change