(555d) CO2 Separation From Coal-Fired Power Plants by Regenerable Mg(OH)2 Solutions
CO2 Separation from Coal-Fired Power Plants by Regenerable Mg(OH)2 Solutions
Hari K. Bharadwaj†, Joo-Youp Lee† *, Xiang Zhou‡, Lei Cheng‡, Tim C. Keener‡
†Chemical Engineering Program, ‡ Environmental Engineering Program, School of Energy, Environmental, Biological, and Medical Engineering, University of Cincinnati, Cincinnati, OH 45221-0012
World energy demand is expected to increase by 57% from 2004 to 2030 which will undoubtedly produce a concurrent increase in atmospheric GHG levels unless something is done to mitigate the release of CO2 to the atmosphere. In response to this, a method is proposed of effectively, efficiently and reliably separating CO2 from flue gases for potential sequestration purposes by means of the absorption of CO2 in slurry containing magnesium compounds conducted at 52 °C, followed by a regeneration step conducted at 65 °C. Mg(OH)2 is readily available commercially, and/or may be easily and economically reclaimed from coal-fired power plants using lime-based flue gas desulphurization systems (FGD). The CO2 scrubbing system will be operated as a regenerable system where a concentrated CO2 gas stream is created for further processing, and the magnesium reclaimed for further absorption of CO2. The process has many advantages including proven absorption technology, no modification of the existing boiler heat-transfer configuration, low temperature CO2 regeneration, and the use of magnesium by-products for further SO3 control. This presentation will demonstrate our current research efforts in CO2 absorption and regeneration including magnesium chemistry, lab-scale absorber operation, magnesium carbonate formation, and vapor-liquid-solid equilibrium for CO2 stripper design and operation.
Keywords: CO2 separation, Coal-fired power plants, magnesium hydroxide