(259e) Techno-Economic Analysis of Water-Lean Solvent Carbon Capture Systems in Natural Gas Combined Cycle Power Plants for High Capture Rate

According to U.S. Energy Information Administration (EIA), over 100 coal-fired plants were replaced or converted to natural gas between 2011 and 2019, while more conversions is expected in the future (EIA, 2020). Giving this trend, investigating low-cost carbon capture and sequestration (CCS) applicable to natural gas combined cycle (NGCC) power plants becomes important. However, efforts on carbon capture in NGCC power plants remained predominantly centered on aqueous amine solvent systems, which are usually energy intensive (Stowe & Hwang, 2017) due to the water vaporization/condensation within the process. Previous studies (Jiang et al., 2023) suggested that CO₂ Binding Organic Liquids (CO2BOLs), a class of water-lean solvent (with < 5wt% water) developed by Pacific Northwest National Laboratory, can achieve an estimated carbon capture cost below $40/tonne CO₂, 15% lower than the industrial benchmark, for coal-fired power plant. The cost reduction was achieved by minimizing unnecessary water vaporization and condensation.

This study aims to investigate the economic viability of utilizing a water-lean solvent, specifically N-(2-ethoxyethyl)-3-morpholinopropan-1-amine (EEMPA), for NGCC power plant carbon capture. As emphasized by (Du et al., 2021), research on high capture rate from power plants is also important because negative-emission technologies such as direct air capture (DAC) are usually more expensive and less matured. This work further investigates the potential of employing water-lean solvent to achieve zero- and negative-emission for NGCC flue gas. Particularly, process model was developed in Aspen Plus V14, and techno-economic analysis was conducted for capture rates ranging from 90 to 99.8% (CO₂ concentration of treated gas <= 100 ppm). For each capture rate of interest, sensitivity studies were conducted to identify optimal operating conditions. For 90%, 95% and 97% capture, the estimated carbon capture cost of EEMPA was compared with NETL Baseline (Case B32B) (James III et al., 2022). For zero- or negative-emission regime, marginal cost, defined as the extra cost of capture additional amount of CO₂, was used to compare EEMPA with DAC technologies.

References

Du, Y., Gao, T., Rochelle, G. T., & Bhown, A. S. (2021). Zero-and negative-emissions fossil-fired power plants using CO2 capture by conventional aqueous amines. International Journal of Greenhouse Gas Control, 111, 103473.

EIA. (2020). More than 100 coal-fired plants have been replaced or converted to natural gas since 2011. U.S. Energy Information Administration. Retrieved Mar 22 from https://www.eia.gov/todayinenergy/detail.php?id=44636

James III, R. E., Shultz, T., Woods, M., Turner, M., Schmitt, T., Oaks, M., Konrade, J., Bleckinger, M., & Sturdivan, M. (2022). Cost and Performance Baseline for Fossil Energy Plants, Volume 3–Low Rank Coal and Natural Gas to Electricity.

Jiang, Y., Mathias, P. M., Zheng, R. F., Freeman, C. J., Barpaga, D., Malhotra, D., Koech, P. K., Zwoster, A., & Heldebrant, D. J. (2023). Energy-effective and low-cost carbon capture from point-sources enabled by water-lean solvents. Journal of Cleaner Production, 388, 135696.

Stowe, H. M., & Hwang, G. S. (2017). Fundamental understanding of CO2 capture and regeneration in aqueous amines from first-principles studies: recent progress and remaining challenges. Industrial & Engineering Chemistry Research, 56(24), 6887-6899.