Starting point is the observation that every year several million tons of anaerobic digestate are produced worldwide as a by-product of the biogas industry, most of which is used as fertilizer in agriculture. However, in the context of a circular bioeconomy, a more sustainable use of the residual biomass from digestate would be desirable. Against this background, the authors examine digestate from four agricultural biogas plants in the Muensterland region. They show that valuable substances are not degraded during fermentation in typical agricultural and biowaste biogas plants, but remain in the digestate, resulting in the new possibility of upgrading digestate for biotechnological applications.
