Conversion to a circular economy is being discussed to an ever-increasing degree. It is most easy to appreciate what a circular economy is when it is contrasted with the current linear economy, which extracts natural resources, produces, consumes, and creates waste. A circular economy creates a circulation in which – in the optimal case – waste does not exist, since materials, energy and other flows are linked, and can be repeatedly used. Since the extraction of new natural resources and the creation of waste are minimised, a circular economy is better for the environment. This is why Sweden has set as an objective that it should convert to a circular economy.
The European Union currently imports 90 percent of its phosphorus, from limited global reserves. Furthermore, fossil resources in the form of natural gas are used to produce nitrogen for commercial fertiliser. This is a typical example of an activity in the linear economy. When the conditions are suitable for the recycling of phosphorus and nitrogen, together with renewal of biomass, it becomes possible to approach a circular economy, and in this way considerably benefit the climate. And a biogas facility does more than simply reduce fossil-based emissions.Roozbeh Feiz Aghaei and Madeleine Larsson, researchers at Biogas Research Center. Photo credit John Marthinson
– It’s extremely important to promote other biogas solutions than just biogas energy, to demonstrate the key role that biogas can play. People are often surprised at how large a difference a biogas facility can make when it comes to nutrient recycling. It’s been traditional for farms and industrial plants to give away nutrients. Biogas solutions can here make a real difference, not only by increasing the use of fossil-free nutrients, but also by distributing nutrients to those who lack fertiliser. This means that I believe that from now we will start to value other important aspects, in addition to biogas energy, says Madeleine Larsson, assistant professor in the Department of Management and Engineering and researcher at Biogas Research Center.
Links between biogas solutions and industry
The research group at the Biogas Research Center (BRC) has investigated three industries to see how biogas solutions can contribute to nutrient recycling in each case. It has also examined whether it is possible to draw any general conclusions relating to biogas solutions in industrial symbioses.
– One aspect that makes this study interesting is that we look at the correlation between biogas solutions and large industries. This has not previously been done to any large extent. In all three cases we have studied how industrial symbiosis including biogas production has provided several benefits to existing industries and has enabled further local developments, says Roozbeh Feiz Aghaei, assistant professor in the Department of Management and Engineering and researcher at BRC.
The results from the study show that when a biogas facility is located close to a biobased industry, several positive effects may arise, depending on the type of industry. The marine industry, for example, could recycle up to 58 percent of its nitrogen and up to 96 percent of its phosphorus, while at the same time reducing the amount of transport required by 90 percent. The research group believes that it will now be easier to provide evidence of the benefit of biogas solutions for companies and actors in the public sector who are still uncertain of the role that biogas can play in future industries.
– The research suggests strongly that biogas solutions can create the conditions required for synergy with traditional large-scale industries. This is particularly true on a local level. It’s great to have clear quantitative evidence of this, and to be able to provide exact figures for the effect of biogas facilities on nutrient recycling. We mustn’t forget while that energy powers our economy, nutrients keep it alive, says Roozbeh Feiz Aghaei.
This research has been carried out at the Biogas Research Center (BRC), an interdisciplinary competence centre with the overall goal of promoting efficient biogas solutions in Sweden. BRC is financed by the Swedish Energy Agency, Linköping University, the Swedish University of Agricultural Sciences, and more than 20 partners from the academic world, industry, municipalities and several other public and private organisations.
The article: The role of biogas solutions for enhanced nutrient recovery in biobased industries—three case studies from different industrial sectors. Roozbeh Feiz, Madeleine Larsson, Eva-Maria Ekstrand, Linda Hagman, Francesco Ometto, Karin Tonderski. Resources, Conservation & Recycling. DOI: https://doi.org/10.1016/j.resconrec.2021.105897
Translated by George Farrants