Biogas, fertiliser, & algae from pigs: the company putting circular farming in practice
Cooperl, one of the world’s largest pig producers, is creating biogas, biofertiliser, and algal feed from animal waste. Here’s how it’s putting circular farming in action.
Cooperl is a circular agricultural pig farming cooperative based in Brittany, France. Founded in 1966 by 24 pig producers, it now has a turnover of €2 billion a year and 7, 200 employees. Around 2, 700 pig producers are members and most are small family farms averaging 200 sows.
Like other circular enterprises, Cooperl’s driving objective is to profit from zero waste farming. As far as possible, outputs from every process are reprocessed and used as inputs for another. This means that pigs are only one aspect of their business: the cooperative also makes high-value products from agricultural waste, turning nitrogen and phosphorus recovered from manure into mineral fertiliser and farming waste into biogas.
Last year, Ramón Armengol of the European General Confederation of Agricultural Cooperatives stated that farming cooperatives are especially good at adding value to waste. This activity can feed into “energy, manufacturing, and technological and digital systems.”
In 2019, Cooperl opened Europe’s largest non-spreading methaniser, Émeraude Bio-énergie, to process pig manure from 100 of their farms. Twenty-five percent of the input into the digester is pig manure while 40 percent is wastewater from the Cooperl slaughterhouse. The rest is water that is recycled from plant processes or pig urine.
The first step in making biogas is collecting feedstock. This is done using the Trac system, a technology designed by Cooperl and rolled out 12 years ago. The system is a pig house installation that immediately separates urine and manure as it falls to the floor. Liquid waste is washed along a gentle slope while solid waste is mechanically scraped outside the barn. Air ventilation wicks away odours from the air. Around 100 pig farms belonging to the cooperative had installed Trac, collecting around 34, 000 tonnes of solid manure. By moving waste outside the pig houses, it reduces concentrated ammonia emissions. One family farm in Brittany said that installing the system allows them to meet European regulations on gas emissions. The farms sell their waste at around €20 per tonne.
The plant produces 7.5 million metres cubed of biogas a year by using microorganisms to break down the waste matter in the absence of oxygen. Once the carbon dioxide is removed from the organic substance, it becomes biomethane. This is then fed into a gas distribution network, providing 60 million kilowatt hours per year equivalent to the energy needs of 10, 000 homes.
Biogas is the most valuable product that can be made from pig manure but Cooperl’s methaniser also creates biofertilisers using a nutrient-rich by-product called digestate. The plant makes 80, 000 – 100, 000 tonnes of pelleted biofertiliser a year. Cooperl’s biofertiliser is in demand throughout the year.
However, some parts of Europe have a bio-nutrient surplus due to strict EU directives limiting fertiliser application. As a result, Cooperl is redirecting some of their 156, 000 tonnes of raw biogas digestate per year into alternative animal feed. Cost-efficient algal animal feed will be an important boost to the circular bioeconomy. European livestock farmers currently depend on soybean imports from South America. Trials like Cooperls’ are essential in finding energy-efficient ways of producing feed-grade algae.