By pyrolysing dry manure under persistently high temperatures and oxygen-free conditions, we can extract a certain amount of carbon from the circuit, thereby preventing it from being converted into CO2. The extracted gas has a high calorific value, which means that the gas can be used to produce electricity and heat by a gas generator. Manure contains various minerals including phosphorus. The treatment of biomass in very controlled temperatures makes it possible to produce a fertiliser product that maintains the structure of the phosphorus. This achieves a very high phosphorus availability and recycling potential.
The problem: release of CO2 and rapid depletion of the soil phosphorus pool One of the major climate challenges is that regardless of whether the biomass from animals, humans and plants is used as fertiliser, treated as waste or involved in the production of biogas, then the carbon content will react with oxygen and hereby produce CO2, wich is released into the atmosphere. In addition, the use of biomass for energy production without the return of a degradable residue results in the soil being drained for mineral material. This means that fertility must be maintained artificially by the addition of NPK fertilisers (nitrogen, phosphorus, potassium), which are relatively CO2 heavy to produce.
The Earth's phosphorus resources are under increasing pressure.
The solution: Biogas via pyrolysis Biochar formed under oxygen-free conditions and controlled heat can isolate and bind carbon, after which the carbon is retained in the soil instead of escaping into the atmosphere as CO2. Biochar consists mainly of C-atoms, which it takes more than 1,000 years to convert into CO2. This means that it is possible to increase the earth's pool of carbon as carbon is taken out of atmospheric circulation. Due to the porous structure of biochar, it can retain nutrients and release them slowly. That makes it an interesting fertiliser. The mineralisation process makes it possible to maintain the availability of the phosphorus and thus make it recyclable. Our preliminary studies show that a thermal mineralisation plant from Frichs Pyrolysis, can produce 300-400 KW and 60-80 kg of biochar containing 4-5 kg of phosphorus by mineralizing, 200 kg of pure and dry chicken dung per hour. The biochar is completely dry, odourless and easy to handle, making it an attractive fertiliser for agriculture, forestry and gardeners. Biochar from 1 ton of dry chicken dung reduces the conversion of carbon into CO2 by a minimum of 0.3 tonnes of CO2.
Market 17 million tonnes of manure *) are produced annually in Denmark. Frichs Pyrolysis' plant can be adjusted to different types of biomass and will thus be able to handle all types of manure as long as they are dried up. In the same way, the plant can be set up to handle other types of biomass, such as sludge or straw etc. In Danmark, there are 400 wastewater treatment plants that generate a total of more than 140,000 tons of sludge per year.
Cooperation Frichs Pyrolysis and Springkilde Æg (Eggs) have been collaborating on this technology for the past 5 years. The cooperation originally occurred because Springkilde wanted to convert its manure from a waste product into a value-adding product. Frichs Pyrolysis, who has worked in engine technology for decades, was already developing a thermal mineralization plant. One of the prerequisites for making such a plant work is a completely dry biomaterial. Springkilde has therefore invested in the development of an efficient drying plant. By reusing hot air from the buildings' ventilation systems, the manure from the farm's chickens is converted into a dehydrated biomass product that can be used as a raw material in Frichs Pyrolysis' mineralization plant. The parties have now established an official cooperation to complete the development of a thermal mineralization plant with the capacity to process 6 tons of biomass per day. It is expected that the first plant will be operational in the second quarter of 2020 and that after test run and adjustments it will be possible to produce new installations from the fourth quarter of 2020.
*) Manure from cattle, pigs and poultry measured in dry matter. The total quantity is more than 60 million tonnes of wet matter. Source: Danmarks Statistik and Søhøjlandets Regnskabskontor.