Photo: DAFC

Biofilters to reduce climate impact from pigs

Biofilters, which break down methane, may be an important step towards reducing the carbon footprint of Danish pig production in a cost-effective way. SEGES Danish Pig Research Centre is part of a GUDP funded project, which will develop and test a new type of filter in pig production.

Denmark’s pig production accounts for methane emissions which are the equivalent of 1.45 million tonnes of CO₂-equivalents per year. The Green Development Demonstration Programme (DUPD) is funding the BIOMET project, which will provide a solution.

The Technical University of Denmark, SEGES, COWI, PFH Miljø & Anlæg and Copenhagen University are set to demonstrate the potential of biofilters as an important and cost-effective technological solution to reducing the worst 'climate sinner' – methane gas - which is formed in the stomachs of animals and in slurry.

Biofilters are expected to reduce the climate impact from pig slurry by 15 per cent. There will also be significant side benefits in that air filtration from slurry tanks through biofilters will also reduce ammonia emissions and odour.

Specifically, the parties will develop, design and test the biofilter system. The filter consists of compost filled with methane-digesting bacteria. The compost is put into large containers or buried at the side of a slurry tank. The concentrated methane from the covered slurry tank is sucked out and conducted through the biofilter.

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The aim is full-scale testing facilities in 2021
The technology is already known as it was developed to convert methane from old landfills. DTU has been working on the technology for almost 15 years. COWI also has experience with biofilters from the installation of biofilters at landfill sites. With regard to the current project, the idea is to transfer the technology to slurry tanks under different conditions.

"Our target is to have climate-neutral Danish agriculture by 2050. This requires specific solutions and I believe that the BIOMET filter is a step towards reducing methane emissions from slurry tanks,” says Trine Barret, Head of Department, Livestock Innovation at SEGES. “We’re looking forward to putting our professional agricultural insight to good use and helping to create solutions that can be used and implemented in Danish agriculture.”

In addition to reducing methane emissions from pig production, BIOMET will also be developed for dairy farms where it will be used in cowsheds and in slurry tanks.