Postdoctoral researcher for the optimisation of microalgae production for biofuels - ALGOSOLIS

Nantes Université; France; Sur place; EUR 35 000 - 45 000; Plein temps

Résumé du poste

A French university is seeking a postdoctoral researcher in microalgal bioengineering. The role involves optimizing culture parameters in photobioreactors and outdoor systems, evaluating nutrient sources, and developing hydrodynamic models. Applicants must hold a PhD in a relevant field and have strong experience in chemical engineering. Excellent English communication skills are required. The position is full-time and based in Nantes, with a starting date of March 2, 2026.

Prestations

Transport subscription up to 75% supported

Access to university restaurants at preferential rates

Access to sports and university libraries

Qualifications

• PhD or equivalent in Biotechnology, Bioengineering, Environmental Engineering, or related fields.
• Strong experience in chemical engineering.
• Solid background in microalgal or microbial cultivation.

Responsabilités

• Conduct experimental optimization in photobioreactors and raceway ponds.
• Evaluate new nutrient sources for lipid production.
• Develop hydrodynamic models for mixing efficiency.

Connaissances

Chemical engineering expertise

Microalgal cultivation

Process control

Hydrodynamics knowledge

Analytical methods (GC, HPLC)

Project management experience

Problem-solving skills

Statistical skills

Fluent English

Formation

PhD in Biotechnology or related field

Outils

Photobioreactor systems

HPLC

GC

Description du poste

Organisation/Company Nantes Université Research Field Engineering » Chemical engineering Researcher Profile Recognised Researcher (R2) Positions Postdoc Positions Country France Application Deadline 30 Nov 2025 - 23:59 (Europe/Paris) Type of Contract Temporary Job Status Full-time Hours Per Week 37h15 Offer Starting Date 2 Mar 2026 Is the job funded through the EU Research Framework Programme? Horizon Europe Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Scientific Context

Microalgae are emerging as one of the most promising renewable resources for producing biofuels, bioproducts, and CO₂‑mitigating biomass because of their rapid growth, high lipid content, and ability to valorize residual nutrients (Chisti, 2007; Wijffels & Barbosa, 2010). However, the challenge lies in reconciling high productivity with environmental sustainability and economic feasibility, especially when up‑scaling from controlled laboratory photobioreactors (PBRs) to outdoor, low‑energy systems.

While closed PBRS ensure rigorous control of environmental variables and high areal productivity, recent comparative studies indicate that open raceway ponds (ORPs) can offer superior energy efficiency, cost‑effectiveness, and scalability for large‑volume biomass generation under certain usage scenarios (Narala et al., 2016; Usman et al., 2024). Their low infrastructure and operational energy demands make them particularly attractive for decentralized or seasonal production, where access to solar light and local resource recycling outweigh precision control (Skifa et al., 2024). Life‑cycle assessments confirm that energy use in closed PBRs—particularly from pumping, lighting, and cooling—represents the main environmental hotspot (Gurreri et al., 2024), whereas outdoor raceways relying on sunlight can achieve carbon footprints one to two orders of magnitude lower for comparable dry biomass outputs.

Low‑tech yet integrated cultivation chains enhance this advantage further when coupled with harvesting and water‑reuse processes such as simple sand filtration. Slow or bio‑sand filters can efficiently remove suspended solids and organic residues, allowing partial nutrient recovery and safe reuse of culture media at minimal energy cost (Esen, 1991; Liu et al., 2019). Reusing cultivation water significantly reduces freshwater and nutrient inputs without necessarily compromising algal growth, positioning filtration‑based recycling as a key enabler of sustainable large‑scale microalgae systems (Lu et al., 2020). The harvesting constitutes another bottleneck for large‑scale developments. Significant challenges originate from the small cell size and low biomass concentration (0.5‑5.0 g L⁻¹) of microalgae suspension in cultivation medium (T. Mathimani 2018). Traditional methods such as centrifugation, flocculation‑flotation or filtration suffer from large energy demands, long processing time or use of chemicals. New sustainable methods need to be implemented.

Such circular system designs, combining low‑energy open ponds and low‑impact water treatment, present a viable alternative to intensive PBRs in specific scenarios—for example, seasonal outdoor operations, co‑location with wastewater or flue gas sources, or regions prioritizing low capital and energy inputs over year‑round consistency. Exploring this trade‑off between process intensity and circular efficiency is central to the research objectives of this postdoctoral project.

Scientific Challenges and Objectives

The main scientific bottlenecks to address include:

• Achieving optimal balance between growth rate and lipid accumulation under nutrient stress.
• Scaling up laboratory findings from controlled photobioreactors to outdoor semiindustrial raceways while ensuring productivity stability.
• Modeling hydrodynamics and energy‑efficient mixing regimes in large‑scale open ponds.
• Developing and testing water, gas, and nutrient recycling strategies integrated with downstream processing.
• Quantifying the impact of culture parameters on HTL biocrude yield and quality.

Main Tasks and Responsibilities

The postdoctoral researcher will:

• Conduct experimental optimization of culture parameters (light, nutrient composition) in bench‑top photobioreactors and outdoor raceway ponds.
• Evaluate the use of new sources of nutrients including NaHCO₃ as an alternative inorganic carbon source to replace CO₂ gas streams.
• Apply nitrogen stress and other stressing strategies to maximize lipid production without compromising overall productivity.
• Develop hydrodynamic models to improve mixing efficiency and energy use in open ponds.
• Perform biochemical analyses (lipid, protein, carbohydrate quantification) and monitor growth kinetics.
• Assess the influence of seasonal variations (light, temperature) on productivity and robustness of cultures.
• Coordinate with consortium partners to correlate cultivation conditions with upstream processes.
• Evaluate mass and energy balances, nutrient cycles, and LCA‑relevant data for sustainability assessments.
• Design and test optimization strategies for biomass harvesting and process water reuse, including filtration and nutrient recovery.
• Assist the project PI and participate to the project management (meeting and reporting).

Chisti, Y. (2007). Biodiesel from microalgae. Biotechnology Advances, 25(3), 294–306. DOI: 10.1016/j.biotechadv.2007.02.001

Wijffels, R.H., & Barbosa, M.J. (2010). An outlook on microalgal biofuels. Science, 329(5993), 796- 799. DOI: 10.1126/science.1189003

Narala, R.R. et al. (2016). Comparison of microalgae cultivation in photobioreactor, open raceway pond, and hybrid systems. Frontiers in Energy Research, 4, 29. DOI: 10.3389/fenrg.2016.00029

Gurreri, L. et al. (2024). Life Cycle Assessment Based on Primary Data of an Industrial‑Scale Microalgae Plant. Chemical Engineering Transactions, 109, 499-506.

Esen, I.I. (1991). Algae removal by sand filtration and reuse of filter material. Water Research, 25(7), 885-890. DOI: 10.1016/0043-1354(91)90298-J

Liu, L. et al. (2019). Applying bio‑slow sand filtration for sustainable water treatment. Polish Journal of Environmental Studies, 28(4), 2673-2683. DOI: 10.15244/pjoes/89544

Usman, H.M. et al. (2024). A Comparative Analysis Assessing Growth Dynamics of Raceway and Photobioreactor Systems. Bioresource Technology Reports, 28, 101367. DOI: 10.1016/j.biteb.2024.101367

Skifa, I. et al. (2024). Microalgae cultivation in raceway ponds: advances, challenges, and future trends. Algal Research, 78, 103157. DOI: 10.1016/j.algal.2024.103157

Mathimani, Mallick, (2018) A comprehensive review on harvesting of microalgae for biodiesel – Key challenges and future directions, Renewable and Sustainable Energy Reviews, 91,1103. doi.0.1016/j.rser.2018.04.083.

Where to apply

E-mail [e-mail]

Requirements

Research Field Engineering » Chemical engineering Education Level PhD or equivalent

Skills/Qualifications

• Degree: PhD in Biotechnology, Bioengineering, Environmental Engineering, Microbiology, or a related field.
• Strong experience in chemical engineering for processes design and operation
• Solid background in microalgal or microbial cultivation, photobioreactor operation, and process control.
• Knowledge of bioprocess design, hydrodynamics, or model-based optimization.
• Understanding of microbial stress physiology and biochemical analysis techniques.
• Expertise in water treatment, waste valorization, or residue reuse would be a strong asset.
• Competence in analytical methods such as GC, HPLC, or TOC analysis.
• Experience in project management
• Strong problem‑solving, statistical, and writing skills.

Specific Requirements

• Fluent English (written and spoken).

Languages ENGLISH Level Excellent

Research Field Engineering » Chemical engineering Years of Research Experience 4 - 10

Additional Information

• Commitment to professional equality, diversity and inclusion and addressing gender‑based and sexual violence
• Membership in the EUniWell European Alliance committed to wellness
• Certified HR Excellence in Research since 2022 as part of the HRS4R strategy
• Transport subscription up to 75 % supported
• Sustainable mobility package, in line with the institution’s commitment to sustainable development
• Access to university restaurants with a preferential rate
• Access to sports, university libraries and other activities on campus
• Website of the research unit : https//:algosolis.com

1 QUAI DE TOURVILLE, BP 13522, 44035 NANTES CEDEX 01