The German biogas specialist WELTEC BIOPOWER continues to be very active on the Japanese market. Thanks to its many years of project experience in earthquake zones – in Japan and Greece – WELTEC BIOPOWER is able to adapt its technical solutions to seismically active areas in the shortest possible time using special structural engineering.
Processing of fermentation residues ensures operational material cycle
Two digesters are available in Yamagata Prefecture to feed the 80 tons of cattle manure per day, which is used exclusively to generate electricity and heat in the 250-kilowatt plant. WELTEC‘s scope of supply also includes two storage tanks, a pump container, a separation unit and the combined heat and power plant (CHP). In addition to the biogas project, a WELTEC BLUE WATER plant with a processing capacity of 50,000 tons of digestate (manure and wastewater from milk production) per year is currently being constructed. The treatment technology separates the digestate from the biogas plant in a multi-stage process into solid and liquid fertilizer and dischargeable water. The resulting solid phase offers a wide range of marketing options, such as use as fertilizer in the field or as bedding in stables. This enables the operator to make additional savings on transport costs by reducing the volume of the source material.

The distribution of output materials varies depending on the dry matter content of the fermentation residue. In this project, the amount of solid fertilizer is around 3%, the nutrient concentrate 29% and the water 68%. Thanks to the sophisticated modular design, the industrial technology can be easily expanded in the future. A WELTEC BLUE WATER plant in Reichenbach in Vogtland, Germany, was already put into operation in March 2024.
Special solution for digesters for processing pig and cattle manure
From 2025, the operators of the 450-kilowatt plant will be filling a mix of 18 tons of cattle manure and food waste from the surrounding area into their digesters every day. WELTEC‘s innovative modular digester system makes it possible to individually adapt the diameter and height to meet customers‘ volume requirements or local building regulations, such as height restrictions. Instead of the usual height of 6.30 m, the digesters have been adapted to a height of 5.03 m. At both plant locations, the electricity is fed into the grid and the heat is utilized for efficient fermentation in the digesters. The fermentation residue from the 450-kilowatt plant is processed in sewage treatment plants near the sites before being used as fertilizer. A further plant is currently being planned in Nagano Prefecture. The height of the digester is also adapted as a special solution to 05.03 meters and equipped with a capacity of 450 kilowatts.

WELTEC CONTROL for quick access
The installed, web-based WELTEC CONTROL software gives Japanese operators quick access to all important system parameters. The system with its intuitive user interface also simplifies feeding processes thanks to the FellowFeed and GuidoFill functions as well as exportable reports as evidence for banks and experts. If faults occur, WELTEC offers operators training and support via remote control. Equipped with this technology and local biomass sources, the projects are exemplary for the economical operation of small biogas plants.