My brewery anaerobic digestion experience, part III

By February 25, 2015Anaerobic, Treatment

This is the last in my series of articles on brewery anaerobic treatment for now. Here is part 1 and here is part 2.

Anaerobic treatment definitely works for treatment of brewery wastewater. In general, anaerobic pretreatment removes about 90% of the BOD. Anaerobic treatment is not a big consumer of energy, and it generates biogas- a renewable energy. Anaerobic is a fairly expensive treatment technology. There are patents and royalties out there to consider, plus the biogas handling gets expensive.

An idea to grow in to an anaerobic installation is to treat spent yeast in the anaerobic digester at first.  This will generate heaps of biogas off a fairly small input.  As your brewery grows you can remove the yeast incrementally, still generating biogas, but now it’s off the comparatively dilute process wastewater from the brewery- which is where most breweries face restrictions.  This is a common strategy to provide enough food for a digester, before the brewery has grown enough to provide the nutrients required for efficient operation.

Following up anaerobic treatment with aerobic treatment is often a good idea. With these combined technologies 98% BOD removal is possible.

Aerobic treatment of brewery effluent is possible. This is a topic for another article, but it’s generally cheaper to install than anaerobic but more expensive to operate due to energy demands.

In any case, treatment with anaerobic or aerobic technology is an expensive proposition. There are capital funds, operating funds, labor, repairs and maintenance, and equalization ahead of the system. With these factors in mind, these technologies make the most sense for large brewers. Anaerobic treatment is very common at large breweries on the scale of Heineken, Anheuser-Busch, etc. The technology is slowly making headway in to the craft beer market, Sierra Nevada and New Belgium to name a few.

Proven suppliers of anaerobic technologies for breweries include Biothane and Paques. Biothane has more installations in the US than anyone, Paques has more installations globally. There are many other suppliers, some engineering companies such as Symbiont can even build and install these systems themselves. There is also a new wave of suppliers entering the market, such as Cambrian Innovations. As time goes by they will get more installations and generate a track record. Call me conservative, but based on my Newbio experience you can appreciate my ‘don’t be a guinea pig’ position with regards to new technologies. That being said, there are often significant incentives available to the guinea pigs.

Thanks for sticking with me as I described all of this. Treatment at a brewery is a very complicated endeavor, and there are a lot of more details out there. My biggest pieces of advice are to have a good wastewater model, check references, visit installations, and pay attention to contract verbage.  Please don’t hesitate to contact me with any questions or comments.

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