Farming Monthly National October 2016 | Page 42

| Slurry Liquid manure volume reduced by half Efficient Slurry and Digestate Processing with „Kumac“ from WELTEC. erman biogas specialist WELTEC BIOPOWER now offers a proven solution for the processing of slurry and digestate for livestock owners and biogas plant operators. The fully automated processing system „Kumac“ reduces the liquid manure and digestate volume by 50 percent. In a four-stage procedure, clear water, liquid fertiliser concentrate and valuable solid matter are extracted from the source material. G WELTEC BIOPOWER‘s processing concept is equally suitable for users from different areas, such as pig and cattle owners and biogas plant operators Regions characterised by agriculture are faced with a high accumulation of slurry and digestate, while the areas suitable for spreading the nutrients are limited. In the future, restrictive laws will impose even stricter regulations for handling the nutrient surplus. Against this background, operators are finding it more and more costly to store and dispose of liquid manure and digestate. WELTEC BIOPOWER‘s Kumac processing system represents a sustainable, economic solution for reducing the quantity, thereby improving the transportability and volume of the nutrient surplus. The functional principle is based on several tried and tested subprocesses, which, in combination with custom developments, are highly effective within the framework of an overall process. To separate the solid and liquid matter in the first step, flocculants are added to the liquid manure and digestate. In this way, certain nutrients are fixed, and it becomes easier to separate the solid matter from the liquid phase with the belt filter press. Moreover, the additives alleviate the odour emissions. The drained solid matter has a dry matter content of about 30 percent and can be used as fertiliser, compost or litter or, in the case of 42 | Farming Monthly | October 2016 slurry, as biogas feedstock. Subsequently, the remaining liquid phase is passed through a flotation tank in order to separate further small particles and suspended matter. Any remaining solid particles are removed by a fine filter. In the next step, the filtrate traverses a three-stage reverse osmosis process in order to concentrate salts and nutrients. The resulting liquid fertiliser is rich in nitrogen and merely accounts for one quarter of the original volume. The major portion of the treatment products consists of clear water (50 percent), which can be introduced to the water cycle after being processed in the ion exchanger. The scalable modular system can be used from an amount of 50,000 t of slurry or digestate a year. If the processing needs increase, a combination of several Kumac lines can easily be implemented. However, Kumac processing also excels with its www.farmingmonthly.co.uk