Biogas production is essentially based on organic materials and biological processes; hence it can contribute to the transition toward a biobased economy. In comparison with other biofuels, biogas is more flexible and can be produced from many different types of feedstock, including biomass containing various shares of carbohydrates, lipids and, both from primary and secondary raw materials. However, a significantly expanded biogas production is dependent on good business conditions, in turn related to societal acceptance and support. There are many factors that can make a biogas solution more or less suitable for both producers and the broader society. Among the many influencing factors, the choice of feedstocks (biomass) for producing biogas and biofertilizer is of strategic importance. But, to assess the suitability is complicated, because it is linked to many different challenges such as cost, energy balance, environmental impacts, institutional conditions, available technologies, geographical conditions, alternative and competing interest, and so on. Suitability includes aspects related to feasibility for implementation, potential for renewable energy and nutrient recycling, and resource efficiency. In this article, a multi-criteria framework is developed for assessing the suitability of producing biogas from different types of biomass (feedstocks). This framework allows learning about the limitations and opportunities for biogas development and more informed decision making, both in industry and policy. Existing, or forthcoming, biogas and biofertilizer producers who are considering altering or expanding their production systems can benefit from a better understanding of different choices of feedstock that are or can be (potentially) at their disposal; thus, identify hotspots, weak points, and possible candidates for implementation in future. The framework is reasonably comprehensive, yet it is simple enough to be used by practitioners. It could help to minimize the risk of sub-optimization or neglecting important risks or opportunities. This article, the first of two associated articles, is focused on the framework itself. The framework is applied to assess the suitability of producing biogas from “stickleback”, which is a non-edible fish in the Baltic Sea region. In the companion article (Part II), four other feedstocks are assessed, namely ley crops, straw, farmed blue mussels, and source-sorted food waste.
This research is performed within the Biogas Research Center (BRC), which is a transdisciplinary center of excellence with the overall goal of promoting resource-efficient biogas solutions in Sweden. The BRC is funded by the Energy Agency of Sweden, Linköping University, and more than 20 partners from academia, industry, municipalities and other several public and private organizations.