(649g) Multi-Concentration CO2 Capture at a 0.7 MWe Post-Combustion Pilot Plant

A post-combustion CO₂ capture technology at the 0.7 MWe scale implemented at the E.W. Brown Generating Station at Harrodsburg, Kentucky primarily funded by the U.S. Department of Energy, National Energy Technology Laboratory (DOE NETL) employs various technological approaches including a two-staged stripping process to lower the regeneration energy of solvents and consequently decrease the associated cost of electricity of the process. Recycle of higher volume CO₂ concentration from the secondary stripping as combustion air to the boiler allows higher amount of CO₂ to be fed to the absorber for the benefits of enhanced mass transfer to be studied at different inlet flue gas CO₂ concentrations.

While the flue gas generated at the plant from coal will typically have CO₂ concentrations at ~12-14%, to mimic conditions for capture from natural-gas plants, the process was modified in recent studies where the flue gas was diluted with a stream of ambient air to about 4% CO₂ inlet concentration and process conditions set to obtain a capture efficiency of at least 90%. A comparative analysis of steam requirements and regeneration energy of the solvent will be presented. The University of Kentucky (UK) CO₂ capture technology is applicable to any second-generation advanced solvent and to a wide range of CO₂ concentrations such as for coal-fired or natural gas plants with specific conditions required to maximize solvent performance (e.g., lean and rich loading ranges), heat exchange in the process to minimize energy requirements. The differences in the extent of reactions for the different inlet CO₂ concentrations and solvent circulation rates in the absorber for example, affect heat release in the absorber resulting in varied temperature profiles, will be discussed and related to the impacts and effectiveness of intercooling for the different conditions.