At the 11th International Conference on Waste and Biomass Reuse Engineering (WasteEng 2026), held in A Coruña, Spain, from July 7 to 10, 2026, researchers from IMT Atlantique and the GEPEA laboratory (Sary Awad, Angelica Raharjo, and Yves Andres) presented the latest important advances in the European COCPIT project. The presentation, entitled “Dark fermentation as an essential step in a SAF biorefinery concept: insights from the COCPIT project,” highlighted how dark fermentation represents a key step in the integrated transformation of microalgae into sustainable aviation fuels.

Research Key Points:

• Biomass Characterization (Parachlorella kessleri): The study compared the composition of the microalgae in a state of regular growth, under nutrient deprivation, and the residual fraction obtained after lipid extraction. The post-extraction residue showed a marked concentration of carbohydrates, confirming it as the ideal raw material for the dark fermentation process.

• Pretreatment Optimization: The application of a dilute thermochemical pretreatment significantly increased the release of fermentable carbohydrates compared to untreated biomass, making them readily available for biological conversion.

• Green Hydrogen Production (H₂): Dark fermentation applied to the lipid extraction residue demonstrated the highest efficiency in green hydrogen production, confirming the high conversion potential of the carbohydrate-rich fraction.

• Energy Self-Sufficiency and Process Circularity: The mass balances integrated into the COCPIT concept show that the hydrogen generated by the dark fermentation of the residue is more than sufficient to cover the entire needs of the subsequent lipid hydrotreatment step (HEFA process). This result ensures the system’s self-sufficiency in the required hydrogen, promoting a circular, high-value biorefinery model.

The COCPIT project’s integrated approach demonstrates that true sustainability lies in the circularity of processes: transforming manufacturing residues into clean hydrogen is key to producing low-impact aviation fuels.