Soeren Meyer chose Vogelsang

He uses a liquid feeding system and a RotaCut for solid matter feeding

The focus of our family farm is pig fattening in a closed system and bull fattening. In 2010, I learned about biogas as a supplementary and farm mainstay through my master's thesis. After that, I started planning a biogas plant for our farm. Our plant consists of two digesters operating in parallel and a final storage, which the plant began working in November 2011. In addition to maize silage and slurry, CCM and rye flour was added to the daily feed ration at the beginning. These fed into the digester using a walking floor and two screw conveyor systems.

Immediately after the last detailed work completed and the system functioned properly, I looked at optimisation options, including on the input side. To reduce the substrate costs, I tried to replace maize silage and especially CCM and rye flour with green rye. Both the mixers and the solid matter feeding were suitable to a limited extent so that I could only use small amounts of green rye.

After detailed advice and visits from the Vogelsang experts on site, I decided to convert to a liquid feeding system. This system consisted of a large pusher floor, an EnergyJet solid matter feeder and a downstream RotaCut RCX cutter, which went into operation in May 2016. The feeding process now performs trouble-free, the entire biogas plant operates more efficiently and my working day is much less stressful despite the fact that I could increase the dung volume from 4 t to 8 t per day. An additional 8 t of green rye  has also been introduced to replace even more of the old feed ration, which the new system can process much more easily than the old one. I reduced the expensive maize ration from 30 t to 20 t per day, without the need to feed expensive CCM or rye flour . Nevertheless, floating layers and jammed slide valves are a thing of the past. Even the main pump operates smoothly and with less wear since the changeover. The RotaCut equipped with a foreign matter separator also showed me the high amount of stones and metal parts contained in the solid matter and have so far ended up in the digester. Thanks to the more homogeneous organic suspension, the power requirement of the mixers and service time has significantly decreased. In total, I save now approximately 200 kWh per day –12,000 euros per year in terms of energy costs. Considering all factors, I expect a return on investment within about four years.