(553c) Modeling, Optimization, and Design of Experiments of a Rotary Packed Bed Contactor for Ngcc–Based CO2 Capture Using Solid Sorbents

As fossil fuels continue to be a significant contributor to the world’s energy mix, new technologies for post–combustion CO₂ capture will continue to be important in meeting carbon mitigation goals. Specifically, natural gas, which has become a major source of electricity in the United States, presents a significant challenge due to the low volumetric/molar composition of CO₂ in the flue gas (~4%). To address this challenge, the U.S. Department of Energy’s Carbon Capture Simulation for the Industry Impact (CCSI²) initiative has been developing models and tools that provide insight into cost-effective technologies for Carbon Capture Utilization and Storage (CCUS). Recent CCSI² publications have focused on modeling and optimization of fixed and moving bed contactors using a tetraamine–functionalized metal–organic framework (MOF) for NGCC–based CO₂ capture (Hughes et al., 2024; Yancy-Caballero et al., 2023). This presentation expands on these prior publications by developing a first-principles model for a rotary packed bed (RPB) contactor, which is then used for multi-objective optimization studies of energy requirement and productivity. Additionally, a model-based design of experiments (MBDoE) framework, which has previously been presented for a fixed bed capture system (Wang and Dowling, 2022), is applied to the RPB model.

Aqueous solvents are the leading technology for post-combustion capture from fossil fuel power generation plants but can suffer from high energy costs and corrosion. Our recent works have focused on a family of solid sorbents, tetraamine–functionalized MOFs, which have been reported as promising sorbents for NGCC–based CO₂ capture due to their unique two-step cooperative adsorption isotherms and stability under steam regeneration conditions (Kim et al., 2020). The optimal selection of the contactor type for solid sorbents is still not well understood and can depend on both the sorbent properties and capture application. Fixed beds are well studied in the literature but can suffer from mass and heat transfer limitations as well as complicated cyclic operation. Moving beds help address these limitations, but continuous movement of the sorbent particles can cause significant attrition. In this work, we model the tetraamine-appended MOF, N,N′-bis(3-aminopropyl)-1,4-diaminobutane (3-4-3)-appended Mg₂(dobpdc), immobilized on the RPB matrix. As the bed rotates, the MOF captures CO₂ from the flue gas in an adsorption section and is then regenerated in a separate section using steam to desorb and recover CO₂. The model, developed using Pyomo (Hart et al., 2017), is dynamic, pressure-driven, and considers 2–D variation in the axial and circumferential direction. Model equations are taken from Ezeobinwune (Ezeobinwune, 2020), and isotherm and kinetics models are taken from our previous modeling works. Multi-objective optimization studies are performed for two scenarios: post–combustion capture and a polishing step process in which a separate capture process has already captured 90% of the flue gas CO₂. Additionally, a measurement optimization and MBDoE analyses are performed using Pyomo.DoE to determine the best choice of measurements and experiments to maximize the information gained, reduce parameter uncertainty, and minimize the cost of the experimental campaign.

Acknowledgement

The authors graciously acknowledge funding from the U.S. Department of Energy, Office of Fossil Energy and Carbon Management, through the Carbon Capture Program.

Disclaimer

This project was funded by the Department of Energy, National Energy Technology Laboratory an agency of the United States Government, through a support contract. Neither the United States Government nor any agency thereof, nor any of its employees, nor the support contractor, nor any of their employees, makes any warranty, expressor implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, or any of their contractors.

References

Ezeobinwune, C.E., 2020. Modeling of Rotary Packed Beds for Reactive and Non-Reactive Systems (MS). West Virginia University Libraries. https://doi.org/10.33915/etd.7508

Hart, W.E., Laird, C.D., Watson, J.-P., Woodruff, D.L., Hackebeil, G.A., Nicholson, B.L., Siirola, J.D., 2017. Pyomo — Optimization Modeling in Python, 2nd ed, Springer Optimization and Its Applications. Springer International Publishing. https://doi.org/10.1007/978-3-319-58821-6

Hughes, R., Yancy-Caballero, D., Zamarripa-Perez, M., Omell, B., Matuszewski, M., Bhattacharyya, D., 2024. Modeling and Techno-Economic Optimization of a Tetraamine-Appended Metal–Organic Framework for NGCC-Based CO₂ Capture Using Fixed Bed Contactors. Energy Fuels 38, 2511–2524. https://doi.org/10.1021/acs.energyfuels.3c03802

Kim, E.J., Siegelman, R.L., Jiang, H.Z.H., Forse, A.C., Lee, J.-H., Martell, J.D., Milner, P.J., Falkowski, J.M., Neaton, J.B., Reimer, J.A., Weston, S.C., Long, J.R., 2020. Cooperative carbon capture and steam regeneration with tetraamine-appended metal–organic frameworks. Science 392–396. https://doi.org/10.1126/science.abb3976

Wang, J., Dowling, A.W., 2022. Pyomo.DOE: An open-source package for model-based design of experiments in Python. AIChE Journal 68, e17813. https://doi.org/10.1002/aic.17813

Yancy-Caballero, D., Hughes, R., Zamarripa, M.A., Omell, B., Matuszewski, M., Bhattacharyya, D., 2023. Isotherm modeling and techno-economic analysis of a TSA moving bed process using a tetraamine-appended MOF for NGCC applications. International Journal of Greenhouse Gas Control 128, 103957. https://doi.org/10.1016/j.ijggc.2023.103957