HAIDAR Rima : Hydrates en milieux confinés pour application au captage et stockage d’hydrogène et de dioxyde de carbone

Résumé de thèse :

Partition of CO2 into clathrate hydrate cages: investigation by vibrational spectroscopy

Gas hydrates are crystalline compounds formed from water and gas molecules under specific temperature and pressure conditions. They represent a huge potential for various applications, including energy storage [1] and CO2 capture [2]. Their natural occurrences on Earth [3a] or possibly in the solar system [4], make them a credible option as natural endo- (Earth) and exogenous (Europa, Enceladus) gas and energy reserves [3b], and provides a better understanding of the formation history of these systems.

This research primarily focuses on the characterization of the formation process and storage capacity of gas hydrates, as well as the examination of the partition of CO2 into clathrate cages. Binary and ternary mixtures forming simple or mixed gas hydrates were selected for (1) their relevance in a carbon capture context and (2) to highlight the specific partition of CO2 into the cages of structure I: CO2-H2O, 20%CO2+80%N2-H2O, 10%CO2+80%N2-H2O, and 90%CO2+10%C3H6. Vibrational spectroscopy (ex: FTIR) is used to analyze CO2 sig- natures in the large and small cages, and retrieve CO2 relative partitioning into the cages. The synthesis process involves a two-stage approach in which the ice particles are exposed to the gas or gas mixture under controlled conditions of temperature (-3°C or 3°C) and pressure (25-120 bar). In addition, the kinetics of gas hydrate for- mation are studied through volumetric measurements and experiments involving vapor deposited ice as starting material with different levels of compaction. Gas absorption calculations are performed to determine the rate of hydrate formation and gas storage capacity. This comprehensive approach provides a better understanding of the structure, composition and kinetics of CO2-based gas hydrates. It will help to improve the development of hydrate-based technologies and gas storage methodologies.

[1] Farrando-Perez et al., Nature (2022) 13:5953
[2] Chazallon & Pirim, Chem Eng Sci. (2018), 342, 171-183

[3a] Chazallon et al., Marine & Petroleum Geol. (2021) 124, 104785; [3b] Boswell et al., (2020) In Natural Gas Hydrates: Status of Potential as an Energy Resource, Future Energy, 108-130

[4] Villanueva et al., Science, (2023) 381, 1305-1308; Shibley & Laughlin, Planet. Sci. J., (2021) 2:221

Doctorant : HAIDAR Rima

Directeur de thèse : CHAZALLON Bertrand, PRIM Claire