Qingdao, China

Biogas plant to reduce air pollution

Pingdu is one of the most efficient agricultural centres in Shangdon Province and one of the regions with the largest amount of manure and crop residues such as maize straw, sugar beet pulp or straw.

The tonnes of crop residues are not only a major challenge for local waste management, but also for the environment: in many places, farmers illegally burn crop waste, which causes severe environmental and air pollution. To circumvent these problems and increase the usefulness of straw, a 37-hectare biogas plant with three digesters and three secondary fermenters was commissioned in October 2017. Up to 20,000 m3 of natural gas is produced here per day, which is fed directly into the gas grid. The waste heat generated in the process is used directly to heat the fermenter.

A GIANTMIX FR SP and an OPTIMIX 2G with GDD are installed in each of the six tanks. The gas-tight GDD ceiling feed-through enables maintenance of the submersible agitator without lowering the level in the tank. In addition, the polymer-coated agitator blade of the GIANTMIX FR SP is especially suitable for highly abrasive media such as maize straw and is corrosion-resistant.