Bridging The Knowledge Gap for Solvent Development for Transformational Solvent Systems for Post-Combustion CO2 Separations

D.J. Heldebrant
Pacific Northwest National Laboratory,
United States

Keywords: carbon capture, fossil energy, greenhouse gas

Summary:

The United States Department of Energy’ (DOE) office of Fossil Energy (FE) has been tasked with aiding in the reduction of greenhouse gas emissions from flue gas generated from fossil fuel combustion. Aqueous amines are the most maturity technology for acid gas scrubbing from flue gas sources, though the energy requirements are cost prohibitive by FE estimates. In order to lessen the energy penalties associated with capture to acceptable levels, R&D investments are being made towards developing lower energy solvent technologies. A recent trend in solvent design is the design of CO2 capture using a minimal amount of water, such that the energy needed to boil and condense water is lessened. The chemistries of each of these solvents are vastly different, though they are quite similar in that they operate with little or no water as a solute. Shifting away from water can result in energy reductions of more than 40% compared to aqueous amine formulations with projections of up to 50% reductions in parasitic load to a coal-fired power plant. While the energetics show potential, these new solvent systems face many technical challenges and knowledge gaps before they can be ready for commercialization. Three critical knowledge gaps needed for advanced solvent development are presented with a focus on how these gaps could be addressed, with the goal of enabling deployment of these technologies by DOE’s 2030 timeframe.