CO2 Flue Gas Scrubber Technology Michael Ng University of Texas Department of Chemical Engineering Background ► Flue gas is exhaust gas that exits to the atmosphere, which come from boilers, furnaces, or steam generators ► CO2 is a greenhouse gas that contributes to global warming ► There are around 6,000 coal-fired power plants around the world (Imai) ► 55% of global electricity comes from coal as being the fuel source (Imai) Coal-fired Power Plant From http://www.biblelife.org/energy-coal-fired-plant.jpg Post Combustion Technology There are different ways to capture CO2 with the use of amine solvents: ► Monoethanolamine (MEA) ► Mixture of MEA and methydiethanolamine (MDEA) ► Piperazine/ Potassium Carbonate MEA Absorber/Stripper Configuration From http://www.netl.doe.gov/publications/proceedings/01/carbon_seq/7c1.pdf Piperazine/ Potassium Carbonate ► Current research done by Dr. Rochelle and graduate students ► Study the thermal properties and kinematics of CO2 absorption using PZ/ K2CO3 ► Degradation rate of solvent vs. MEA PZ/ K2CO3 degrades at 1.3 mm/hr MEA degrades at 5 mm/hr ► Corrosion Integrated Gasification Combined Cycle Economics (CO2 Capture) Economics (Costs) Six Rules to maximize the effectiveness of PC (adapted from Gibbins, Crane, et. Al) ► ► ► ► ► ► 1. Add heat to the steam cycle at as high a temperature as possible 2. Reject heat from the steam cycle, in the steam extracted for solvent regeneration, at as low a temperature as possible. 3. Produce as much electricity as possible from any additional fuel used, consistent with rejecting heat at the required temperature for solvent regeneration. 4. Make use of waste heat from CO2 capture and compression in the steam cycle. 5. Use the latest solvent developments. 6. Exploit the inherent flexibility of post-combustion capture. Skyonic SkyMine Process Recommendations ► Pursue post combustion technology Use solvents that do not degrade as fast as MEA (i.e. PZ/ K2CO3) ► IGCC has a high capital investment, but allows for high CO2 recovery Questions?