RESEARCHER PROFILE: PhD / R1: First stage Researcher
RESEARCH FIELD(S)1: Engineering
MAIN SUB RESEARCH FIELD OR DISCIPLINES1: Physics
JOB /OFFER DESCRIPTION
Used solvents generated by the chemical industry are often incinerated, even though processes exist to recycle them (distillation, extraction, pervaporation, etc.). Recycling these solvents helps reduce environmental impact, both in terms of resource conservation and pollutant emissions. Conventional processes are sometimes ineffective when dealing with mixtures that form azeotropes or have properties that prevent their separation by distillation. Extraction requires adding a third component to enable separation, which then necessitates additional separation processes to remove the added component. Pervaporation is an alternative separation process that can optimize depollution. Given the current focus on reducing environmental impacts, applying the pervaporation process appears to be a relevant solution to the need for reducing emissions from many polluting industries.
Pervaporation is a membrane separation process known for its energy efficiency. It allows complex separations depending on the choice of membrane. For example, at an industrial scale, it can be used to dehydrate bioethanol, extract solvent traces from aqueous effluents, or perform organic-organic separations. The transfer mechanisms involved and the mass flux densities are significantly different from those found in porous membranes used in microfiltration and ultrafiltration. The sub-nanometric scale at which these phenomena occur leaves no room for conventional observation techniques. However, existing models rely on global measurements carried out at the process scale under steady-state conditions for validation.
The commonly accepted separation principle is based on a difference in the chemical affinity of the membrane material toward the various components of the liquid mixture to be separated. The mass transfer occurs through three successive mechanisms. First, selective absorption takes place, which is strongly influenced by the specific affinities between the membrane material and the different entities present in the feed mixture. Second, selective diffusion occurs through the membrane material due to the unequal mobility of the species within the membrane. This second process is the major limiting factor in mass transfer, driven by the local activity gradient that exists for each entity at every point of the membrane. Finally, the last step consists of desorption in the vapor phase of the diffused material on the downstream side of the membrane, which is maintained under reduced partial pressure. Each of these three steps contributes to selectivity and permeability, which quantify the performance of the process.
Recent experimental and modeling results obtained in the laboratory have highlighted that the amounts of heat involved in mass transfer are significantly lower than expected based on the previously described mass transfer model. These findings raise fundamental questions about the liquid-vapor phase transition within a dense polymer membrane. This leads to numerous perspectives, both in terms of a better understanding of the phenomena and industrial optimizations. Optimization will involve selecting efficient membranes, choosing appropriate operating conditions (upstream and downstream pressure, heating mode, recirculation), and modeling coupled mass/heat transfers. The ultimate goal is to achieve both adequate production and selectivity while using the least possible amount of energy. This process engineering approach aligns with the laboratory's research themes related to sustainable development challenges.
TYPE OF CONTRACT: TEMPORARY / JOB STATUS: FULL TIME
APPLICATION DEADLINE: 01/07/2025 00:00
ENVISAGED STARTING DATE: 01/09/2025
ENVISAGED DURATION: 36 months
JOB NOT FUNDED THROUGH AN EU RESEARCH FRAMEWORK PROGRAMME
WORK LOCATION(S): Laboratoire M2P2, Equipe Procédés Membranaires, Aix-Marseille Université - Europôle de l'Arbois BP 80, Bat. Laennec, Hall C, 13545 Aix-en-Provence
WHAT WE OFFER: Gross monthly salary: 2 200€ in 2025 – 2 300€ from 2026 onwards
Additional information: The Euraxess Center of Aix-Marseille Université informs foreign visiting professors, researchers, postdoc and PhD candidates about the administrative steps to be undertaken prior to arrival at AMU and the various practical formalities to be completed once in France: visas and entry requirements, insurance, help finding accommodation, support in opening a bank account, etc. More information on AMU EURAXESS Portal
QUALIFICATIONS, REQUIRED RESEARCH FIELDS, REQUIRED EDUCATION LEVEL, PROFESSIONAL SKILLS, OTHER RESEARCH REQUIREMENTS
We are looking for a highly motivated PhD candidate with a background in Process Engineering to work on the energy optimization
Soft skills:
Strong understanding of separation processes (distillation, extraction, pervaporation, etc.).
Interest in experimental and modeling approaches.
Knowledge of thermodynamics, membrane processes, and transport phenomena is a plus.
Ability to work independently and in a team.
REQUESTED DOCUMENTS OF APPLICATION, ELIGIBILITY CRITERIA, SELECTION PROCESS
Please contact the PI
HOW TO APPLY: [email protected]
