Producing protein-based products from microalgae cultivated on anaerobically digested abattoir effluent: Process integration and techno-economic analysis

Abstract

The integration of microalgae production with anaerobically digested effluents might result in development of sustainable processes not only to remove nitrogen but also to produce value-added products rich in protein. This work analyses the feasibility of producing protein-based products derived from microalgae grown on anaerobically digested wastewater by performing techno-economic evaluation. The results show that it would be possible to propose an upstream process flow diagram producing 2.7 kg microalgae from 1 m−3 wastewater with possible production cost of 1.8–8.1 USD kg−1 depending on the scale of anaerobic digested effluent. It would be possible to produce protein isolate, concentrate, and animal feed from anaerobically digested effluents with possible production cost of 33 USD kg−1, 28 USD kg−1, and 6 USD kg−1 respectively at the scale of 1600 m3 d−1 effluent. Although currently the production of protein-based products might not be feasible, increasing the scale of production might result in some feasible outcomes. However, the associated costs regarding collecting more AD wastewater from different sources should be evaluated to increase the scale of production.