Agricultural-based biorefinery

In the project "Agricultural-based biorefinery," we at RISE have developed a concept in which agriculture serves as a large-scale supplier of ILUC-free biomass to a biorefinery. Where the extraction of biomass does not compete with food or feed production and does not have negative effects on long-term soil fertility. The concept, illustrated in the figure, aims to integrate the production of food, feed, and energy. It involves the co-location of local biogas plants with grass protein plants, which supply residual streams to a regional HTL plant that produces bio-oil through hydrothermal liquefaction (HTL). By combining small-scale and large-scale processes, our objective is to enhance profitability and achieve various synergetic effects.

Grass and legume crops serve as the driving force in this concept, generating both animal feed and biofuel. Additional biofuel is derived from manure and other residual streams originating from agriculture, which are subsequently reintroduced to agriculture as plant nutrients. Through expanded grassland cultivation, farms without animals can contribute to an increased biogas production while simultaneously improving the humus content in their soils.

In the project, we engage in collaboration with biogas plants, advisors, and researchers. Our objective is to assess the potential of agriculture-based residual streams in the Region Västra Götaland. A survey is conducted to evaluate the biogas plants' capacity and interest in handling fiber-rich substrates. Practical tests are performed at RISE Processum to examine the production of bio-oil from dewatered digestate, while the biogas potential of the aqueous phase from HTL trials is assessed at RISE in Uppsala. The concept is investigated from a systems perspective, involving the evaluation of costs and mass balances. To calculate the potentials for the concept, we utilize farms located near Vårgårda-Herrljunga Biogas (VH Biogas) as case study farms.

The project contributes to the goal of a fossil-free agriculture by producing biofuels from residual streams for both the farm's own consumption and society’s needs. At the same time, Sweden's degree of self-sufficiency is strengthened through domestic production of fuel, plant nutrients and protein feed. Furthermore, the project contributes to increased soil fertility by introducing grass and legume crops in grain-dominated crop rotations.