Reference : UMR5254-SOPPUY-049
Workplace : PAU
Date of publication : Thursday, August 4, 2022
Scientific Responsible name : Anthony RANCHOU-PEYRUSE (IPREM UMR5254) and Anne BATTANI (LFCR UMR5150)
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 3 October 2022
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
The PhD position proposed here will be part of the task “Identification of biological and geochemical markers associated with the presence of H2 in soil and subsurface”.
The work that will be carried out in this task aims to specify the biogeochemical characteristics of a natural environment rich in H2, and to identify the relevant markers associated with its presence. An innovative multidisciplinary methodology is developed, combining meta-omics, cultural and geochemical approaches, and will lead to the very complete characterization of this environment.
This doctoral work will be based on advanced geochemical tools to characterize the hydrogeochemistry of the sites studied and to specify the role of hydrogeological networks in the genesis and migration of hydrogen.
From the sampling of water sources selected on the basis of a hydrogeological study being carried out by Engie/Storengy, the classic isotopic tracers, such as 18O, 2H, 3H and 14C, will be used to determine the origin and residence time of the waters. The physico-chemical parameters (temperature, salinity, etc.) and the composition of major and trace elements of these sources will make it possible to constrain calculations of water-rock interactions, and to specify the lithologies encountered by the circulations. These results will be compared with compositional and isotopic data on dissolved rare gases (He, Ne, Ar, Kr, Xe). The measurements of rare gases, which are chemically inert, will provide information on the origin of these gases and quantify the various potential components. A dating obtained by the analysis of the radiogenic rare gases 4He and 40Ar will be carried out, and compared with the residence times estimated by classical isotopy. The concentrations of rare gases in solution, depending on the physico-chemical conditions in situ, will also provide information on the various processes that have affected the waters. Finally, the composition and isotopy of the major gases dissolved in the water samples (H2, CH4, N2) will be measured. The association and origin of these gases will be discussed with regard to the hydrogeological study and the geochemical and biological results provided by the other tasks of the chair. A comparison of the signatures obtained with those of waters and gases from other H2-producing intra-cratonic systems, such as that of Kansas for example, will be carried out, and will make it possible to highlight potential common features.
Depending on the interest of the PhDl student and the first results, we plan to complete these analyzes carried out in situ with an experimental study in which the gas phase and the composition of the microbial communities would be fully controlled and monitored over time. Such an approach would both strengthen our knowledge of the biogeochemical phenomena at work.
Required profile :
- a Master's degree (or an engineering degree) in geochemistry
- skills in hydrogeology would be appreciated
- taste for analytics (mass spectrometry)
- a strong interest in multi-disciplinarity, in particular microbiology and an open mind.
- The ability to work in a team
- writing and communication skills in English
Hydrogen (H2) is the smallest molecule and it is a very promising resource because its combustion produces only water and releases a huge amount of energy. Nowadays, H2 is mainly obtained by reforming hydrocarbons and this process leads to the production of CO2. H2 can also be generated by electrolysis of water using excess energy produced by renewables. It can then be transported and stored in large quantities in natural underground reservoirs, such as aquifers and depleted hydrocarbon deposits.
Although quantities are yet to be determined, H2 is also produced as a geological resource from natural emissions. H2 can thus be both an energy vector and a resource and, as such, plays a central role in Engie's R&D strategy.
This PhD thesis project benefits from a unique working environment. Indeed, it is the result of a larger project, the industrial chair ORHYON co-financed by ANR and Engie, which brings together industrialists and scientists, in particular researchers in geochemistry, geology and microbial ecology. This five-year project mobilizes six doctorates and post-docs focused on H2 mobility and biogeochemical reactivity in natural porous media, from deep environments to the surface. Concretely, the results provided by this project will lead to a better understanding of the processes controlling the migration and retention of H2 in geological formations, but also to new tools and methodologies to reduce the risks associated with geological storage, to specify the potential of H2 as an energy resource and provide technical advice for its exploration and production. The PhD student will come out strengthened by a unique experience that he/she will be able to put to good use in academic or applied research.
The PhD will take place at the University of Pau and Pays de l'Adour, Laboratory of Complex Fluids and their Reservoirs (LFCR) and at the Institute of Analytical Sciences and Physico-Chemistry for the Environment and the Materials (IPREM), Pau, France
Constraints and risks
Work with gas (N2, CO2, H2)
For more information, please contact : email@example.com et firstname.lastname@example.org
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