Assessing the Viability of Solid Sorbents for CO2 Capture From Coal-Fired Power Plants

Carbon capture and sequestration (CCS) can be an important component of reducing worldwide CO2 emissions from stationary point sources, such as coal-fired power plants. Aqueous amines and ammonia are being demonstrated for CO2 capture in a temperature swing cyclic process. Solid sorbents can also be used in a similar process, but have the potential to drastically reduce the energy required to release the CO2 during material regeneration. However, the majority of solid sorbent research is being conducted on lab-scale samples without significant consideration of process and/or equipment design.

ADA Environmental Solutions is examining available sorbents as well as process equipment options to assess the viability and accelerate development of solid sorbents as a CO2 capture option through a DOE Cooperative Agreement and supplemental funding from EPRI and industry. During the first phase of this program, ADA is evaluating materials from top sorbent developers throughout the world. Over 90 materials have been tested using a fixed bed screening device and simulated flue gas over multiple adsorption/regeneration cycles. These materials have been compared based on their respective theoretical regeneration energies. Several materials have properties that are promising when compared to industry benchmarks. Furthermore, additional materials are scheduled for characterization as materials are improved and more developers become aware of the opportunity to have their materials evaluated.

Materials demonstrating the most promise from the initial tests have been characterized in a fixed-bed reactor on actual flue gas from a lignite-coal fired electric generating unit (EGU). Field testing in a fluidized bed reactor is schedule for late 2009. In a parallel effort, large-scale process options are being reviewed and evaluated. An update on the progress of the project, including results from screening tests (i.e. theoretical regeneration energies and working CO2 capacities) as well as options for process equipment will be discussed.&'