Recovery and transformation of slurry into biomethane and organic fertilizers

Several people from the project posing in a field with cows in the background

Repsol, Naturgy, and Reganosa are collaborating with Impulsa Galicia to develop the circular economy with a project that will transform surplus livestock manure and other waste into biomethane, organic fertilizers, and neutral CO2 of biological origin on a large scale.

This initiative has been created to optimize slurry management in the northern Spanish region of Galicia, reduce dependence on foreign energy, facilitate compliance with new European standards, and help decarbonize industry, households, and mobility.

What is the project about?

The project involves the phased deployment of a network of plants throughout Galicia to recover surplus slurry from cattle, pigs, and poultry mixed with a smaller amount of organic fraction of separated collection and organic industrial waste from the agri-food sector to produce renewable energy.

The first renewable gas generation plant will be located in Meirama (Cerceda), a fair transition zone, and then the other anaerobic digestion plants will be located at different points, according to a distribution based on the Galician map of livestock farms, thus optimizing logistics between the origin of the waste and the new facilities.

The project has an annual treatment potential of 6,000,000 tonnes of waste with a production, in addition to organic fertilizers and neutral CO2, of 1.1 TWh/year of biomethane to be injected into the natural gas grid. 

This renewable gas will be employed to decarbonize different sectors, such as residential, industrial, and transportation, and it will be used at the Repsol refinery in A Coruña.

FarmerRemains of pruning and slurry. Electricity and heatBiogas is used for boilers or electric generators. DigesterThey are taken to a plant for processingThe waste is introduced into a digester where it decomposes in the absence of oxygen (anaerobic process), giving rise to two elements. BiogasMade up of methane, carbon dioxide and hydrogen. DigestateMineral mix (nitrogen, phosphorus, potassium, calcium...). Water treatmentSewage sludge. BiomethaneCO2 is extracted from biogas and biomethane remains, which can be injected into the natural gas network or used as fuel in industry, households or autogas-powered vehicles. FertilizerTo fertilize the fields in agricultural exploitations. Garbage collectionOrganized fraction of urban solid waste. IndustrialFood, chemistry, paper. FarmerRemains of pruning and slurry. Electricity and heatBiogas is used for boilers or electric generators. DigesterThey are taken to a plant for processingThe waste is introduced into a digester where it decomposes in the absence of oxygen (anaerobic process), giving rise to two elements. Water treatmentSewage sludge. BiomethaneCO2 is extracted from biogas and biomethane remains, which can be injected into the natural gas network or used as fuel in industry, households or autogas-powered vehicles. FertilizerTo fertilize the fields in agricultural exploitations. Garbage collectionOrganized fraction of urban solid waste. IndustrialFood, chemistry, paper. BiogasMade up of methane, carbon dioxide and hydrogen. DigestateMineral mix (nitrogen, phosphorus, potassium, calcium...). FarmerRemains of pruning and slurry. Electricity and heatBiogas is used for boilers or electric generators. DigesterThey are taken to a plant for processingThe waste is introduced into a digester where it decomposes in the absence of oxygen (anaerobic process), giving rise to two elements. Water treatmentSewage sludge. BiomethaneCO2 is extracted from biogas and biomethane remains, which can be injected into the natural gas network or used as fuel in industry, households or autogas-powered vehicles. FertilizerTo fertilize the fields in agricultural exploitations. Garbage collectionOrganized fraction of urban solid waste. IndustrialFood, chemistry, paper. BiogasMade up of methane, carbon dioxide and hydrogen. DigestateMineral mix (nitrogen, phosphorus, potassium, calcium...). FarmerRemains of pruning and slurry. Garbage collectionOrganized fraction of urban solid waste. . Electricity and heatBiogas is used for boilers or electric generators. FertilizerTo fertilize the fields in agricultural exploitations. Water treatmentSewage sludge. IndustrialFood, chemistry, paper. BiomethaneCO2 is extracted from biogas and biomethane remains, which can be injected into the natural gas network or used as fuel in industry, households or autogas-powered vehicles. DigesterThey are taken to a plant for processingThe waste is introduced into a digester where it decomposes in the absence of oxygen (anaerobic process), giving rise to two elements. BiogasMade up of methane, carbon dioxide and hydrogen. DigestateMineral mix (nitrogen, phosphorus, potassium, calcium...). FarmerRemains of pruning and slurry. Garbage collectionOrganized fraction of urban solid waste. Electricity and heatBiogas is used for boilers or electric generators. FertilizerTo fertilize the fields in agricultural exploitations. Water treatmentSewage sludge. IndustrialFood, chemistry, paper. BiomethaneCO2 is extracted from biogas and biomethane remains, which can be injected into the natural gas network or used as fuel in industry, households or autogas-powered vehicles. DigesterThey are taken to a plant for processingThe waste is introduced into a digester where it decomposes in the absence of oxygen (anaerobic process), giving rise to two elements.