Modelling Studies on Reactive Absorption of Carbon Dioxide in Monoethanolamine Solution from Flue Gas in Coal Based Thermal Power Plants

Abstract

In this paper the detailed theoretical investigation on absorption of carbon dioxide, from flue gas in coal based thermal power plants has been presented. For absorption studies, monoethanolamine solution is considered as a solvent. The mathematical model for the absorption column has been developed by considering thin film model approach. Unified method is used for an overall estimation of carbon dioxide absorption. The carbon dioxide concentration profile at a given stage, using the thin film layer model, has been predicted at 298 K and 318 K. From the results it is noted that carbon dioxide concentration decreases from interface concentration at equilibrium to a minimum of 0 kmol/m3 up to a distance of ±2 micrometers. Overall estimation of carbon dioxide absorption has been carried out using the unified model approach. The total amount of carbon dioxide absorbed in absorption column is estimated to be 95.60% of the inlet carbon dioxide with 30 trays, L/G ratio of 8.5 and carbon dioxide flow rate of 95.74 kmol/m3. The results revealed that reactive absorption is very effective in absorbing carbon dioxide into monoethanolamine solvent.    

Keywords

• Carbon dioxide absorption
• Mass transfer
• Henry’s law
• Film theory
• Monoethanolamine.