Conceptual design of a novel route for microalgae biorefinery associating tannery wastewater treatment with the production of biofuels and carbon dots

Abstract This study proposes a microalgae biorefinery integrated with tannery wastewater treatment. Each step of the route is analyzed, together with its yields, using data from the literature. The process begins with tannery wastewater treatment, followed by biomass recovery and pyrolysis. The three pyrolysis products – bio‐oil, biochar, and gas – are evaluated, and potential applications are suggested based on the yields achievable with current processing technologies. The results indicate that 1000 m 3 of tannery wastewater can produce 11.58 t of dry microalgae biomass, yielding 109.6 L of diesel, 184.3 L of gasoline, and 68.79 kg of carbon dots.