SYSTEM FOR RECOVERING PHOSPHOR.
Phosphor recovery system
Alltech Dosieranlagen GmbH has developed a system for recovering phosphor from pig slurry on the basis of the P-RoC-process (Phosphorous Recovery from waste and process water by Crystallisation of Calcium Phosphate) developed at the Karlsruhe Institute for Technology. Alltech was nominated for Europe’s largest environmental and economy prize, GreenTec Award 2014 in the category Recycling & Resources for this project.
PHOSPHORUS – ESSENTIAL NUTRIENT AND FINITE RESOURCE.
Phosphorus (P) is one of the most important nutrients for the organism. It plays a key role both as energy supplier and also as a component of DNA for the transfer of genetic information. As essential nutrient, phosphorus cannot be substituted and therefore in the event of a lack to a limiting growth factor in all organisms. In view of the key role of phosphorus and the limit of P - resources the necessity for its recovery is apparent. Then the geogenic availability of phosphorus are according to estimations, are only sufficient for another 70 years.
CYRYSTALLISATION PROCESS FOR NUTRIENT RECOVERY.
Phosphorus is used in Western Europe to 80% for the production of fertiliser. Alltech developed a demonstration plant to treat pig slurry for phosphorus recovery and to create a secondary raw material. Slurry is usually pre-treated prior application, to use for energy primarily in co-fermentation plants. Following fermentation a substrate is created that is used agriculturally and should close the nutrient circle. The substrates phosphorus and nitrogen are mainly used in agriculture. This limits the quantities available depending on the surface area, i.e. high phosphorus content in the substrate causes that additional areas must be leased to distribute the substrate and further addition of minerals added to fertiliser for i.e. special cultivation are required. If the nutrients are separated, especially phosphorus and nitrogen before or parallel to the fermentation process from the slurry, on the one hand the fermentation process is stabilised, which can cause an increase in the methane distribution and on the other provides the nutrients in a transportable and dosable form. Hereby the regional reduction of the substrate is ensured and additionally fertiliser is gained. The winning of nutrients occurs through a crystallisation process that can easily be fitted into the stream of slurry.
IMPORTANT SIGNIFICANCE FOR ENVIRONMENTAL PROTECTION.
The phosphorus entry into water from diffuse sources is in accordance with LAWA information (2003) approx. 58 %. Of this 46 % comes from erosion and run-off. Hereby, the over dunging of agricultural land has a direct connection with the eutrophication of waters. A further source of environmental pollution is through slurry emissions, as with the implementation with ground bacteria laughing gas is produced which has a high relevance for global warming (greenhouse effect) and the destruction of the ozone layer. An environmentally friendly distribution of slurry (as required, distribution close to the ground) and stall dung economy only partly reduces this problem.
DEMONSTRATION PLANT FROM ALLTECH BEGINS OPERATION.
The origination for the idea for a recovery of phosphorus from pig slurry was on the one hand the fact that this raw material cannot be substituted and on the other the limited availability. The development of the demonstration plant was subsidised by the European Union and the State of Baden-Württemberg. The demonstration plant for phosphorus recovery entered initial operation on 22nd January 2014 at the Landesanstalt für Schweinezucht in Boxberg (Baden-Württemberg).