Techno-economic evaluation of stillage treatment with anaerobic digestion in a softwood-to-ethanol process.
ABSTRACT: BACKGROUND: Replacing the energy-intensive evaporation of stillage by anaerobic digestion is one way of decreasing the energy demand of the lignocellulosic biomass to the ethanol process. The biogas can be upgraded and sold as transportation fuel, injected directly into the gas grid or be incinerated on-site for combined heat and power generation. A techno-economic evaluation of the spru