Water-energy nexus in biofuels production and renewable based power

In this paper, the water-energy nexus for renewable based processes is evaluated. Process synthesis and integration techniques are used to synthesize the processes and integrate the energy and water, optimizing the consumption of both natural resources. In the analysis of water consumption, it was found that cooling needs and water using technologies are major drivers. Currently, contaminated water is treated for further use. Therefore, the more the energy is integrated, the lower the cooling needs are reducing the water consumed. FT-fuels was identified as the most efficient process in terms of water-energy consumption, with other options being second generation bioethanol via gasification and catalytic synthesis, biodiesel production from cooking oil, and the integrated process that produces biodiesel and glycerol ethers, as long as the rainfall water is not included in the analysis. Otherwise, solar based fuels are more efficient.