AQANA’s DACS® at the Rothaus brewery

AQANA’s DACS® performing at ultra-low temperatures helps Rothaus brewery achieve its ambitious plants of becoming net zero by 2030

Rothaus has a strong environmental commitment and plans to be net zero by 2030 via 7 key steps:

• implementation of reusable sorting system
• use of green energy coming from renewable sources
• generation of heat via a solar thermal system
• installation of solar panels for electricity generation
• revamp of the wastewater treatment plan with an anaerobic system
• usage of electrical driven trucks for distribution of products
• and installation of a wind farm

 

Rothaus project presented several challenges that needed to be addressed in the most efficient way possible:

 

• Maximal reuse of the existing infrastructure, minimizing the investment cost and carbon footprint generated during the plant erection.
• Operation of the anaerobic system at low temperatures, allowing Rothaus to recover as much heat as possible from their effluent, a key element for achieving a net zero operation by 2030.

 

In order to maximize the usage of existing infrastructure as well not interfering with the environment with high visible tanks, AQANA suggested using three of the existing concrete SBR tanks, converting them into the pre-acidification tank (PA), recirculation tank, high-rate Downflow Anaerobic Carrier System (DACS®) reactor and effluent tank, as it can be seen down below:

A thorough investigation, including laboratory tests carried out at AQANA’s laboratory facilities in Leeuwarden, was performed, testing how the anaerobic biomass will behave at such low temperatures. During the tests it was proven the possibility of operating DACS® system at temperatures as low as 25 ºC, achieving reasonable high COD removal efficiencies of 70-80%.

 

The Rothaus brewery is located in the Baden-Württemberg state, Southwest Germany, in the middle of the black forest, with rough winters and considerable amounts of snow, posing another challenge to the project and the ever-present temperature management topic. A custom-made design was made, fitting most of the equipment inside an existing concrete tank, saving Rothaus the need to build a purpose-made technical building.