Slaughterhouse waste: fertilizer or energy resource?

Organic fertilizers where waste from slaughterhouses is part of the mixture are common on organic arable farms (e.g. the product line “Biofer”). In a scientific article published in the journal “Resources, Conservation and Recycling”, researchers from SLU studied the environmental pay-offs to utilize slaughterhouse waste as fertilizer by producing Biofer, compared to using the waste as an energy resource by combustion and using fossil energy to produce fertilizers.

Emissions of acidifying substances and greenhouse gases are lower when the nutrients in the slaughterhouse waste are used for the production of Biofer than if the waste is used as an energy source, while emissions of eutrophicating substances and total energy use are higher. The results were largely dependent on the assumptions made about the products that the slaughterhouse waste replaced.