Starting date: October 1rst 2026
Duration : 3 years
Funding : Doctoral Contract Toulouse INP (PEPR B-Best)
Thesis supervision : Hélène Roux-de Balmann (DR CNRS), Sylvain Galier (Pr UT)

Keywords : Biorefinery, microalgae, membrane processes, circular engineering

This thesis is part of the WAEster project (4 partner laboratories and 2 technology transfer centers), funded by the PEPR B-Best France 2030 Priority Research Program and Equipment “bio-based
products, industrial biotechnologies, sustainable fuels”. The objective is the development of an integrated microalgae culture process on effluents from the
dark fermentation of organic waste to produce Fatty Acid Ethyl Esters (FAEEs), basic molecules for green oleochemistry or biofuel production.

In such an approach, the separation and purification steps have a significant impact, their cost potentially reaching 50% of the total cost. In a previous project, solvent extraction was used to purify
the FAEEs. However, membrane processes, recognized as a sustainable alternative, without the use of solvents and more energy-efficient than thermal separation processes, are particularly well-suited to
the biorefinery context. Their usefulness has been demonstrated in a wide range of applications for concentrating, separating, purifying, or demineralizing liquids containing varying proportions of
organic species (carbohydrates, peptides, amino acids, proteins, organic acids, etc.) and minerals. Studies have highlighted the close dependence of their performances (yield, selectivity) on the
composition of the liquid, particularly its ionic composition and pH. However, very few studies have been conducted on membrane filtration processes for the purification of FAEEs.
In this context, the work proposed in this thesis aims to study the integration of membrane processes at different levels within the overall process.

An experimental study will be necessary to understand the relationship between the characteristics of the fractions (composition, pH), the process parameters and its performance (yield, purity). This study
will be conducted with synthetic solutions of increasing complexity as well as media obtained at various stages of the process. We will initially focus on the purification of the FAEE fractions obtained
after transesterification. The influence of operating conditions, membrane properties, and the composition of the trace element mixture on the yield and purity of the purified FAEEs obtained after
membrane separation will be studied. Secondary streams will also be characterized with a view to their recycling, within a circular engineering approach.

Required background: the candidate needs a general education in chemical engineering (Master degree) with a research experience. Strong skills in chemical engineering, motivation, autonomy,
synthesis, team spirit, good oral and written skills (in French and English).
How to apply: send your cover letter and CV (including contact details of your internship supervisor) @ sylvain.galier@utoulouse.fr @ helene.roux-de-balmann@utoulouse.fr