Anaerobic Industrial Wastewater Treatment in the Brewing Industry

Cause

Oettinger produces beer and soft drinks at its Mönchengladbach site. Wastewater is produced in the brewhouse and in the bottling plant. This wastewater is partially screened and then fed into the municipal sewage treatment plant. The energy content of the wastewater stream is so high that it makes sense to utilize it for energy production under today's conditions. For this purpose, an anaerobic wastewater pre-treatment plant was built on the company premises, which ensures efficient energy recovery through the biogas produced in the reactor and subsequent utilization in the boiler house.

Process

The screened process wastewater is fed into the newly constructed mixing and equalization tank. There, the wastewater contents are equalized and pre-acidified. To prevent solids deposits, the tank contents are circulated with a submersible motorized agitator. The wastewater enters the anaerobic stage via a recooling heat exchanger. In the anaerobic reactor, the wastewater constituents (COD/BOD) are converted into methane and CO2 by bacteria. The resulting biogas collects in the upper tank area and is fed into the gas utilization system via pipelines. Prior to this, a scrubber system with NaOH is used to remove most of the unwanted H2S. Furthermore, a gas cooling system removes condensate from the biogas down to a dew point of 8 degrees. The pre-treated wastewater is fed into a flash aeration system, which ends the anaerobic state, and then fed into the sewage system.