All cheap local biomasses that contain unexploited fermentable sugars should be included in biorefineries. Yet, many current and projected biorefineries have relatively narrow feedstock portfolios. Increasing the feedstock diversity will create value to several stakeholders in the supply chain, by expanding the feedstock market to enter the large-scale 2G bioethanol plants. In turn, this will increase feedstock resource security, creating more competition at the supplier side, and consequently lower overall prices for 2G bioethanol.

In the current study whey, whey permeate, beer production mash, deep litter, potato pulp, rape seed press cake, and saw dust are all investigated as feedstock supplements on 2G bioethanol production of wheat straw. These biomasses can all be found in close proximity to a projected full-scale 2G ethanol plant in Denmark.

The impact of including these alternative biomasses is assessed on the basis of composition, high dry matter enzymatic hydrolysis yields, fermentations yields, and assessment of selected inhibitors and potential fermentation nutrients. The impact of different blend-in ratios for blending in the alternative biomasses in a wheat straw based ethanol production will also be presented, while the optimal point of including the different biomasses in the production will be discussed.