Doctoral theses

Recycling plastic materials is essential for reducing the amount of waste, but currently used mechanical recycling processes have very important limitations (sorting control, color). Chemical recycling will allow a more complete material recovery and this PhD thesis aims at contributing to its development.

Understanding and modeling trace gas emissions from tundra soils to the atmosphere is critical to predict surface-atmosphere feedbacks on current and future global warming. Tundra soils are underlain by permafrost, a thermal condition of the ground which remains at or below 0 °C for two or more years throughout the high latitudes.

A better understanding of the processes resulting in geothermal and/or biogenic gas emissions at the seafloor is crucial in order to quantify gas evolution in the deep ocean and better assess its contribution to global warming.

The Rock-Eval® (RE) thermal analysis was developed at IFPEN during the 1970’s as a standard benchmark tool in oil exploration, and became more and more frequently used during the last 20 years in soil science in order to characterize soil organic matter and its thermal stability.

As our climate is changing the impact of water, or the lack of it, on how we develop and use the landscape is becoming increasingly uncertain. Mountain belts can be thought of as water towers, securing steady flow of irrigation, drinking and industrial water to adjacent population centres.

Fluid-rock interactions play a key part in the evolution of our environment.

The Albien aquifer constitutes a deep reservoir located under the chalk of the Parisian basin composed of unconsolidated clay-sandstone deposits and is considered as a strategic resource for Ile de France in the event of long-term unavailability of classic resources.

The earth’s system is a key provider of energy through its constant release of heat. In most continental areas of our planet, this heat is limited; the thermal gradient is about 30°C/km in most sedimentary basins, and even lower in cratonic areas.

Extreme climatic events such as heavy rainfall or periods of drought can induce changes in the landscape morphology and soil composition. In particular, they can cause mudslides, soil depletion or silting up of watercourses in the absence of suitable facilities. It thus appears crucial to anticipate and prevent these phenomena.

The geochemical composition of water can have a strong impact on the viability of geothermal resource exploration. Depending on its elements, it can cause scaling or corrosion problems or on the contrary, present opportunities for the recovery of co-products such as Lithium.

Plastics, which appeared more than a century ago, have gradually established themselves in a multitude of applications thanks to their interesting properties and their low cost.

In the context of the energy transition, Negative Emissions Technologies (NETs) gain interest each time CO2 atmospheric concentration is measured, as there is no decrease nor even stabilization of this concentration expected in the next years. These NETs are technologies that remove carbon from the atmosphere and sequester it.