Catalyzed CO2 Hydrate Crystallization and Dissociation in Nanoconfinement

R.L. Hartman, New York University (Principal Investigator)

C.A. Koh, Colorado School of Mines (Co-Investigator)

Gas clathrate hydrates (‘hydrates’) are crystalline lattices of hydrogen-bonded water molecules that encapsulate small hydrocarbon (gas) molecules, such as CO2 and methane. They are energy-rich entities that form spontaneously from water and small hydrophobic molecules under specific temperature and pressure conditions, such as in subsurface and suboceanic zones, industrial pipelines, or laboratory synthesis from aqueous solutions.  Hydrates are promising materials for CO2 storage technology. Its abundance worldwide makes carbon science a problem of enormous societal magnitude. Thus, molecular-level understanding of the chemical physics in which gaseous compounds interact with water to form gas hydrates, and vice versa, are of principal importance. In response, in this project we will study of catalyzed CO2 hydrate crystallization and dissociation in nanoconfinement.

The overarching goal of this project will be to discover fundamental molecular-to-pore based multiscale understanding of catalyzed CO2 hydrate crystallization mechanisms in nanoconfinement. Crystallization constrained to microscale gas-liquid or gas-liquid-solid interfaces and geometric nano- and micro-scale structured surfaces will be of interest. Metals (dissociated and atomic layers) and organic semi-clathrates will be introduced as catalysts in the confinements.  Here we hypothesize that metals and organic compounds influence crystallization in nanoconfinement, ultimately changing the preferred nanocrystal orientation, melting point depression, and crystallization kinetics.  Our research team will design highly-ordered nanoporous structures in microfluidics with in-situ spectroscopic methods for measurement of kinetics, study why dissociated metal ions and metal deposits influence CO2 hydrate crystallization in nanoconfinement, investigate why organic amine salts (already known to form semi-clathrates) catalyze CO2 hydrate crystallizations, and design physics-informed neural networks (PINN), based on governing system equations, to develop first-principle crystallization kinetic models. World-class in-situ spectroscopic techniques, including high-pressure microfluidics with in-situ polarized Raman Spectroscopy and Non-Spinning and Magic Angle Spinning Nuclear Magnetic Resonance (NS/MAS-NMR), and physics-informed machine learning methods will be used to study basic hydrate science.