Germany-headed biogas producer and technology supplier Weltec Biopower GmbH has announced that it has commissioned its fourth biogas plant in Japan. "The Japanese appreciate the custom plant design and the benefits of our modular approach, especially because the plant structure with stainless-steel modules facilitates the consideration of the special risks in areas that experience a lot of seismic activity", explains Vladimir Bogatov, who is responsible for sales at Weltec.
According to Weltec, the biogas plant recently went live in Saitama Prefecture, 40 km north of Tokyo. The facility which is equipped with a 450-kW cogeneration power plant is the fourth project to be rolled out by the German manufacturer in Japan.
In terms of substrates, the operator makes use of organic leftovers from the vicinity. Since the raw material mix varies, Weltec ensures a steady biogas output with its biological service. This special service of the biogas specialist also comprises another plant of the same customer.
Residual organics a preferred substrate
Organic residues are the preferred substrates in Japan. The biogas plant in Saitama, too, digests some 12 000 tonnes of organic waste per annum into energy. The substrate mix consists of organic waste and cattle manure from a nearby farm that belongs to the operator.
The largely liquid organics are introduced to the digester by means of a central pump. Solid feedstocks are transported by a dosing feeder with a capacity of 27 m3.
To ensure efficient digestion of this mixture, Weltec Biopower has set up a stainless-steel digester with a capacity of 2 823 m3. Its diameter measures 25.34 m, and its height is 6.3 m.
The upstream substrate storage tank has a capacity of 336 m3, a diameter of 9.31 m, and a height of 5.03 m, and the 525-m3 digestate storage tank (diameter 11.64 m, height 5.03 m), are too both are made of high-quality stainless steel.
Finally, the digestate is separated and the solid phase is dried with special technology in order to further reduce the volume. Most of this residue is used as compost and some of it as fertilizer.
All-inclusive
All in all, Weltec Biopower has provided the customer with an all-inclusive package with “made in Germany” quality along with individual after-sales service.
Subsequently, the Japanese operator also entrusted Weltec with the biological supervision of its other biogas plant, which had been set up by a different provider in 2017. As this plant’s yield was above average, the company’s biology experts had the substrate mix of the old plant carefully analyzed by a Japanese lab.
Based on the results, the raw material mix and the retention time have been optimized. Due to the constantly changing composition of the waste, Weltec will continue to supervise the two plants biologically in order to maximize the gas yield.
