Scientists from the Budapest University of Technology and Economics (Hungary) and Lund University (Sweden) report a techno-economic study on the production of ethanol from softwood (spruce), focusing on the alternative options for stillage management. Stillage is the liquid residue left after the distillation of ethanol from the (alcohol)-fermented broth. In order to improve the economics of ethanol production, attempts are usually made to obtain "co-products" of value from stillage. For example, the stillage can be evaporated for use as animal feed, or as solid fuel pellets. However, evaporation is still an energy-intensive process, entailing cost. As an alternative to stillage evaporation, the techno-economic study investigated the use of anaerobic digestion to produce biogas. The biogas can then either be (1) upgraded to transportation fuel, (2) injected directly into the "gas-grid", or (3) incinerated on-site for combined heat and power generation. Results showed that anaerobic distillation of stillage had a higher overall energy efficiency of 87% to 92%, compared to the reference case. The production cost was said to vary from 4.00 to 5.27 Swedish kronor (or 0.38 to 0.50 euros) per liter. The complete study is published in the open access journal, Biotechnology for Biofuels (URL above).