Cu/TiO ₂ photocatalysts can be considered a promising low-cost alternative to the well-known Pt/TiO ₂ system for hydrogen production under UV-Vis irradiation.

In this work, the anaerobic digestion of three microalgae (Chlorella sp., Nannochloropsis sp., and Scenedesmus sp.) and their residues, resulting from the oil extraction process and the in situ transesterification reaction for biodiesel production, using two inoculums (sewage sludge and poultry manure) for biogas production was investigated. It was found that the biogas production from digestion of oil-extracted microalgae residue with sewage sludge reached values ​​similar to those obtained with raw microalgae (around 500 NL kg⁻¹ VS). Both the volume of biogas generated from the microalgae residue from the extraction process of its oil and the quality of the biogas produced reflect the value of this residue to be valorized by anaerobic digestion. This approach based on a biorefinery concept and focusing on the anaerobic digestion process could be a key technology for energy production from biomass.