Biogas plant adapted for residual material use

Challenge

Steimbker Biogas GmbH & Co KG generates electricity and heat in its biogas plant. The waste heat from the combined heat and power plant is used to heat the greenhouses of a neighbouring nursery, among other things, and the fermentation residues are used as fertiliser on the fields. Previously, mainly silage from maize and other energy crops as well as separated cattle manure were used as energy sources, but now the biogas plant had to be converted to utilise residual materials such as manure in order to comply with the legally prescribed maize cap of 30 per cent from 2026. 
As solid residues are more challenging to process and ferment, it was necessary to modify the biogas plant's feed-in technology. Brandt GmbH planned and realised the entire feeding technology. 

Solution

Brandt installed the LEF 90 - a solid matter feeder that can hold 90 m³ of manure. The container is made of stainless steel to withstand corrosion in the long term. The auger in the LEF container transports the fibrous residue into the MaCBox, an in-house development by Brandt: In the MaCBox (=Mix and Cut in a Box), the substrate is already shredded, mixed with liquid and fed efficiently and evenly to the fermenter as a homogeneous suspension via the pipework system. Instead of only mixing and fermenting the solid substrate in the fermenter, this step is carried out much more energy-efficiently by the MaCBox: the mixing times in the fermenter are halved and electricity consumption is reduced. The fermentation residues resulting from biogas production are not a waste product, but are used as agricultural fertiliser in neighbouring vegetable cultivation, closing the nutrient cycle. 
As the entire feeding technology was configured with standard components such as the LEF and the MaCBox from Brandt and optimally harmonised with each other, the conversion could be implemented cost-efficiently. 
The Steimbke biogas plant is therefore already equipped for future legal requirements, it operates more economically and continues to supply the nursery with energy and the agricultural sector with nutrient-rich fertiliser. A future-oriented example of how renewable energy generation and the circular economy go hand in hand! 

Location

Ostereistedter Straße 6
27404 Rockstedt