Advanced Low Energy Enzyme Catalyzed Solvent for CO₂ Capture

Technical Report · Mon Sep 30 04:00:00 EDT 2013

DOI:https://doi.org/10.2172/1121752· OSTI ID:1121752

Zaks, Alex ^[1]; Reardon, John ^[2]

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1. Akermin Inc., St. Louis, MO (United States); Akermin Incorporated
2. Akermin Inc., St. Louis, MO (United States)

A proof-of-concept biocatalyst enhanced solvent process was developed and demonstrated in an integrated bench-scale system using coal post combustion flue gas. The biocatalyst was deployed as a coating on M500X structured packing. Rate enhancement was evaluated using a non-volatile and non-toxic 20 wt% potassium carbonate solution. Greater than 500-fold volumetric scale-up from laboratory to bench scale was demonstrated in this project. Key technical achievements included: 10-fold mass transfer enhancement demonstrated in laboratory testing relative to blank potassium carbonate at 45°C; ~ 7-fold enhancement over blank in bench-scale field testing at National Carbon Capture Center; aerosol emissions were below detection limits (< 0.8 ppm); 90% capture was demonstrated at ~19.5 Nm³/hr (dry basis); and ~ 80% CO₂ capture was demonstrated at ~ 30 Nm³/hr (dry basis) for more than 2800-hrs on flue gas with minimal detectible decline in activity. The regeneration energy requirement was 3.5 GJ/t CO₂ for this solvent, which was below the target of <2.1 GJ/t CO₂. Bench unit testing revealed kinetic limitations in the un-catalyzed stripper at around 85°C, but process modeling based on bench unit data showed that equivalent work of less than 300 kWh/t CO₂ including all CO₂ compression can be achieved at lower temperature stripping conditions. Cost analysis showed that 20% potassium carbonate in a basic solvent flow sheet with biocatalyst coated packing has economic performance comparable to the reference NETL Case-12, 30% MEA. A detailed techno-economic analysis indicated that addition of catalyst in the stripper could reduce the cost of capture by ~6% and cost of avoided CO₂ by ~10% below reference NETL Case-12. Based on these results, a directional plan was identified to reduce the cost of CO₂ capture in future work.

• Research Organization: Akermin Inc., St. Louis, MO (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: FE0004228
• OSTI ID: 1121752
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES