| dc.description.abstract | A number of carbon capture and storage processes have been designed and implemented in an effort to mitigate the environmental impact of fossil fuel combustion in the energy industry. Since these processes can be retrofitted to existing plants, they offer a mechanism to reduce CO2 emissions without phasing out of fossil fuel use. Of the carbon capture processes available, CO2 absorption with alkanolamines, such as monoethanolamine or MEA, is perhaps the most widely used and viable. In many circumstances, random or structured packing is preferred over trays to provide ample surface area for gas-liquid contact while minimizing pressure drop inside the absorber column of a CO2 absorption unit. However, packed columns are generally more difficult to model than trayed columns. The continuous nature of gas-liquid contact in packing makes rigorous mass transfer models more suitable than the vapor-liquid equilibrium (VLE) models commonly used for trayed columns. Despite the existence of many mass transfer correlations for packing in literature, no known set of correlations is accurate for the full range of available packing types, gas and liquid velocities, and gas/liquid system physical properties. This study seeks to develop a new set of mass transfer correlations useful for modeling CO2 absorption in packed columns. A database of over 1300 values for effective interfacial mass transfer area (ae) and the gas and liquid phase mass transfer coefficients (kG and kL) measured for both random and structured packings by the Process Science and Technology Center group at the University of Texas was consolidated and used to validate the correlations. The correlations for ae, kG, and kL fit the database with average errors of 0.825%, 3.20%, and 7.14%, respectively. Predictions from the correlations were compared to those from other widely used literature correlations, and the new correlations were observed to better match the magnitudes and trends of data in the PSTC database. Finally, the correlations were incorporated into the process simulator ProMax and used to determine the optimal choice of packing on an economic basis to be used in a CO2 absorber treating the flue gas from a 50MW coal-fired power plant. | en |
