PuraSystem uses an innovative process to remove nitrogen from the manure with the aim of reducing the environmental impact. Using the PuraSystem process, liquid manure is treated via stripper and scrubber using energy and acid. The products are nitrogen-depleted manure and ammonium sulphate or citrate. The latter replaces the artificial fertiliser that would otherwise be required.
In a comparative life cycle assessment, we compared the overall environmental impact of the PuraSystem process in two acid variants (sulphuric acid and citric acid) with a reference system (conventional system for manure storage and spreading). We considered material and energy inputs and transport of the PuraSystem, manure storage and spreading by drag hose.
The results show that the treatment of liquid manure with the PuraSystem significantly reduces the environmental and climate impact, even if there are no advantages in storage. This statement applies if sulphuric acid is used for the process. This is significantly more ecological than citric acid. The extent of the benefits or savings that result from depletion depends on various factors such as the nitrogen content of the manure, the effects on storage time and the electricity mix used. In terms of climate impact, the savings range from 79 kg CO2eq to 16.2 kg CO2eq per m3 of manure, depending on the variant.