Job offer

Organisation/Company Laboratoire de Génie Chimique - CNRS - Toulouse INP - UPS

Research Field Engineering » Chemical engineering

Researcher Profile First Stage Researcher (R1)

Positions PhD Positions

Country France

Application Deadline 30 Jun 2025 - 23:59 (Europe/Paris)

Type of Contract Temporary

Job Status Full-time

Hours Per Week 35

Offer Starting Date 1 Sep 2025

Is the job funded through the EU Research Framework Programme? Not funded by a EU programme

Is the Job related to staff position within a Research Infrastructure? No

Offer Description

The research topic concerns the valorisation of calcium-rich sulphurous demolition waste in order to produce one or more mineral products that can be used in the construction sector, by means of accelerated carbonation in aqueous phase. The research, which is part of the PRECIZE project, is coordinated by IMERYS, a world leader in mineral-based specialities for industry, and funded by the France 2030 DEMIBaC (Development of technological building blocks and demonstrators) industrial decarbonisation programme managed by ADEME (the French Agency for Ecological Transition). The research project is unique in that it is based on 3 PhD theses carried out simultaneously with a common objective: the complete development of an operational CO2 mineralisation process, which IMERYS will then develop on an industrial scale.

The PhD work involves the experimental development and modelling of two treatment routes for the production of calcium carbonates from gypsum waste (main mineral phase CaSO4.2H2O). The first route, referred to as direct, operates in an ammonium medium, while the second one involves an intermediate solid product, lime or Ca(OH)2. The aim of the thesis is therefore to develop and model the complete treatment chain using these two routes, by combining experiments in multi-litre reactors, phenomenological modelling and process simulation. In addition to the key process steps of gypsum dissolution and carbonation - which will require an extensive experimental programme for their study -, upstream and downstream stages (solid-liquid separation, injection of gaseous CO2 into the reaction system and management of impurities) will also be investigated. As this work is part of the France 2030 plan for the decarbonisation of the French industry, the performance targets related to CO2 utilisation, energy efficiency of the treatment chain, recycling of process water, etc., will be defined and used as guidelines for process development.

Missions

Experimentation: The experimental work expected constitutes the core of the thesis work and will focus on the implementation, in multi-litre reactors, of the treatment stages enabling calcium carbonate products to be produced from gypsum according to the two abovementioned treatment routes. The experimental work will focus on evaluating the effect of the operating conditions on the carbonation rate and the properties of the products (PCC or cement-like materials and by-products), including temperature, CO2 partial pressure, gas-liquid transfer rate, pH, addition of additives, slurry concentration and the initial properties of the solid (mineral composition, particle size distribution). In addition to monitoring the rate of CO2 consumption, changes in the composition of the liquid phase and the properties of the solids produced (size distribution, elemental composition, mineralogy) will be evaluated using various physicochemical characterisation techniques (e.g. laser diffraction, ICP/AES, XRD, IR and Raman spectroscopy). The nature of the solids and co-products that come out of the process is essential for the project, as they will have to be valorisable by the industrial partner IMERYS.

Modelling: The expected work will range from the phenomenological modelling of the processing stages tested in the experiments to the modelling of the entire processing chain. In addition to modelling the dissolution and carbonation stages, which are the cornerstones of the process to be developed during the thesis, the modelling work will also pay particular attention to the management of aqueous flows and the possible pre-treatment of the fumes and particles used.

Applications:

Applications should be sent to the following contacts: carine.julcour@ensiacet.fr , florent.bourgeois@toulouse-inp.fr

The application file (in the form of a single pdf file) must contain the following information:

1. Concise CV, including current employment status and qualifications obtained
2. Academic background and transcripts
3. Subject of the research internship and letter of appreciation from the supervisor
4. English language level
5. Motivation letter showing that the applicant's profile is suited to the proposed subject.

Where to apply

E-mail florent.bourgeois@ensiacet.fr

Requirements

Research Field Engineering » Chemical engineering

Education Level Master Degree or equivalent

Skills/Qualifications

The candidate must hold a Master's degree in Chemical/Process Engineering and have an initial research experience with pilot reactor units and scale for the development of an industrial process. The proposed subject thus requires a pronounced taste for experimental work and process development. The candidate should have a particularly strong background in chemical engineering process modelling and simulation of processes based on experimental results. Knowledge of techniques for characterising minerals and analysing aqueous solutions, thermodynamic modelling of multiphase systems and analysis of reaction kinetics in the presence of mass transfer resistances will be decisive factors in the selection of candidates for this post-doc position.