Dual-Loop Solution-Based CCS for Net Negative CO2 Emissions with Lower Cost

Proposal Title: Dual-loop Aqueous CCS for Net Negative CO2 Emissions with Lower CAPEX and Offset OPEX/ PIs: Kunlei Liu and Heather Nikolic, University of Kentucky Center for Applied Energy Research (UK CAER). Team Member: EPRI, LGE and KU and ALL4 To address the technical challenge from the low CO2 (~4 vol%) and high O2 (~12 vol%) concentrations in NGCC flue gas along with a very high CO2 capture efficiency (95+%) and 20% cost reduction from NETL B31B in baseline report Rev 4, UK CAER is proposing a dual loop aqueous process to lower the capital cost by 50% and offset the operating cost with negative CO2 emission and hydrogen production. Flue gas enters the primary capture loop, the bottom of the absorber, where 85-90% of the CO2 is removed by a water-lean organic solvent, which is regenerated in a heat driven stripper producing a CO2 product stream of 99+% purity. Followed with a water wash section equipped with in-line cooler for amine entrainment and aerosol removal to <1ppm. The CO2 reduced flue gas then contacts a inorganic solvent, KOH, in the packing-free open tower to remove the remaining CO2 to <100 ppm. The objectives are to: 1) design, retrofit, fabricate and research a dual solvent CCS on the existing UK CAER 0.1 MWth bench-scale post-combustion CO2 capture facility using real natural gas-derived flue gas, augmented to match NGCC CO2 and O2 concentrations with >99+95% CO2 capture efficiency; 2) conduct a TEA to document the benefits of the proposed technology and identify technology gaps for the next scale of development; 3) assess issues of EH&S relating to the solvent and its degradation during long-term operation and extrapolate to commercial-scale application; 4) conduct a LCA to document the document the practical lifetime; 5) develop a TMP for future technology development. This project will be led by UK CAER with Electric Power Research Institute as a subrecipient responsible for the TEA and LCA studies, and ALL4 as subcontractor responsible for EH&S. LGE and KU as a sponsor will provide cost-share to the proposal. Compared to the state-of-the-art solvent-based processes, it is believed that the proposed process will immediately lead to CO2 negative electricity generation in the NGCC power plant with the estimated cost of CO2 capture 20% below the DOE Reference Case B12B.