Low Energy CO2 Capture Enabled by Biocatalyst Delivery System

Abstract This work presents research and development progress to improve biocatalysts, solvents, and system integration to reduce the cost of CO 2 capture from flue gas. Laboratory data and field demonstration illustrate the potential of biocatalyst-enhanced CO 2 capture from coal generated flue gas using non-volatile alkali salt solutions. The first generation biocatalyst system (coated packing) demonstrated 6 to 7-fold enhancement in the volumetric average mass transfer coefficient at 40 °C with 3460 hours on coal flue gas with 80% CO 2 capture on average. The first 2800 hours operated with an aqueous solution of 20% K 2 CO 3 , and the final 660 hours demonstrated a new higher capacity non-volatile alkaline salt solution (AKM24). Lessons learned from the first generation biocatalyst delivery system (coated packing) demonstration are summarized. A second generation biocatalyst delivery system (biocatalyst microparticles) is introduced that shows a greater potential for rate enhancement in laboratory tests. This new biocatalyst system also provides a lower cost method of biocatalyst addition and replacement on-stream. Preliminary modeling estimates show a total equivalent work less than 220 kWh/t CO 2 (including CO 2 compression to 150 bar) in two possible process configurations. Preliminary cost analysis demonstrates potential for more than 30% reduction in CO 2 capture costs relative to NETL Case 12, version 2 (30% MEA with 75 psig cross over steam, bituminous coal power plant).