Biochar integrated into composting to reduce greenhouse gas emissions (Char‑CC)

Composting and biochar production are two sustainable ways for the valorisation and recycling of organic wastes produced in northern Sweden, which can be combined and used synergistically to reduce greenhouse gas emissions and nutrients losses.

Our daily production and consumption activities result in the generation of large quantities of organic residues, including household waste, forestry and pulp & paper industry residues, agricultural waste, bioenergy byproducts, fishery discards, and livestock farming waste. If not properly managed, these wastes become serious greenhouse gas and pollution sources. Instead, they can be circulated and transformed into high-quality soil amendments, fertilizers and plant substrates.

This project's goal is to synergistically integrate the recycling of these waste streams through two complementary technologies: biochar production and composting. The project seeks to fine-tune the process of incorporating biochar into the composting of these residues to produce a high-quality soil fertiliser or plant substrate that also acts as a carbon sink, mitigating greenhouse gas emissions, decreasing the use of fossils-originated fertilisers and nutrients losses, and promoting sustainable food production and soils preservation.

When biochar is integrated into the composting process, volatile organic compounds, greenhouse gases and other odour emissions can be significantly reduced. Additionally, the use of biochar can improve the quality of the composting process and the final product due to its specific physical and chemical properties. Through laboratory and pilot experimental scales, we will evaluate the best conditions for the composting of various residues by adjusting factors such as the amount and particle size of the added biochar, the type of biomass and the pyrolysis temperature for biochar production. Through a Life Cycle Assessment (LCA) and a techno-economic analysis, the environmental, economic and social impacts of this technology development and application will be evaluated and communicated.

The project will be developed in close collaboration with local and regional companies and governmental organisations, which are both waste producers and potential users of the project outcomes. A good appropriation of the produced knowledge would increase the adoption of sustainable practices for production and consumption and the development of related public policies for climate change and pollution fight actions.