(259f) Hydrogen Storage and Carbon Dioxide Sequestration in Tbaf Semi-Clathrate Hydrates: Kinetics and Evolution of Hydrate-Phase Composition by in Situ Raman Spectroscopy

Alondra Torres Trueba,¹ Ivona R. Radoviæ,¹ John F. Zevenbergen,²

Maaike C. Kroon,³ Cor J. Peters^1,3,4*

¹Department of Process & Energy, Delft University of Technology, Delft, Netherlands

²TNO Defense, Security and Safety, Lange Kleiweg 137, 2288 GJ Rijswijk, Netherlands

³ Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven, Netherlands

⁴Chemical Engineering Program, Petroleum Institute, Abu Dhabi, United Arab Emirates

ABSTRACT

Carbon dioxide (CO₂) represents almost one third of the emissions from the combustion of fossil fuels additionally, CO₂ has been identified as the mayor contributor of global warming. Hydrogen (H₂), on the other hand, due to its properties is considered a promising energy carrier. Clathrate hydrates are a potential alternative for CO₂ separation, capture and storage (CCS) as well as a medium for H₂ storage. For instance, clathrate hydrate technologies are less energy demanding and environmentally friendly than other technologies available. However the main disadvantage of clathrate hydrates is the high pressure required for their formation. Recently, tetra-n-butyl ammonium fluoride (TBAF) has been used as an additive to form H₂-TBAF and CO₂-TBAF semi-clathrate hydrates with water, which are stable at much more practical conditions (atmospheric pressure and close to room temperature). Moreover, TBAF is non-volatile which means there is no contamination of the gas phase. These favorable conditions make these two semi-clathrate hydrates particularly attractive for hydrate based technologies.

In order to investigate the potential of H₂-TBAF and CO₂-TBAF semi-clathrate hydrates for H₂ storage and CO₂ sequestration, kinetic data were obtained. The influence of pressure, solute concentration and formation rate was elucidated. Coupled with the kinetic results, the Raman spectra studying the structural changes that take place during formation and dissociation of the H₂-TBAF and CO₂-TBAF semi-hydrates were recorded in situ by Raman spectroscopy. To the best of our knowledge, these are the first results of time-dependent kinetic conditions of H₂-TBAF and CO₂-TBAF semi-clathrate hydrates using in situ Raman spectroscopy in an aqueous solution. Results will be presented at the conference.