A smart way to get wasted

Michael Whelchel

Waste abounds in our current industrial processes. Our manufacturing base was born out of an era when natural resources and energy were seen as unlimited and inexpensive. No longer. Waste is now seen as an opportunity to create new businesses and new technologies. 

Take for instance, PurposeEnergy who has the trademarked slogan Saving the Earth. One Beer at a Time. PurposeEnergy uses patented technology to convert high solids organic waste into methane through anaerobic digestion, which is then used to create heat and electricity. The company’s first target market is the brewery industry, which currently pays for the disposal of its high solids waste, known as trub, from the beer fermentation process. 

PurposeEnergy offers two innovative opportunities to the brewing process: the reuse of previous costly waste material, and the provision of a dependable, cost controlled source of energy. Currently, breweries are only able to convert their organic waste at a low or even negative value.

PurposeEnergy allows breweries to create additional value by converting this waste into high-value, renewable biogas that is used to power the brewery’s processes. The biogas contains all of the fuel value of natural gas as well as the added value of being 100% carbon neutral. The renewable energy introduced by PurposeEnergy can be monetized in the form of carbon offset credits as well as marketed to environmentally conscious beer drinkers.

The technology
While anaerobic digestion has been in use for decades, the ability to apply it to high solids is new. Prior technologies have dealt primarily with wastewater from the brewery process, while high solids waste has generally been given away, or in some cases sold, to local farmers as a feed supplement.  In 2006 there was a breakthrough in dealing with high solids concentrations for generating biogas and PurposeEnergy has exclusive rights to apply this technology to the brewery industry.

PurposeEnergy’s digestion technology is able to process high solids thereby creating five new sources of value from the waste stream. These byproducts/services include:

• byproduct remediation. The process diverts an organic waste stream from entering the landfill and/or municipal wastewater treatment facility.
• biogas production. The digestion converts the organic waste into methane which is used to generate heat and electricity.
• organic fertilizer. This is generated from the leftover material of the digester.
• reduction in greenhouse gases. Through the onsite generation of heat and electricity, the breweries are reducing or eliminating their need for fossil fuels to run their facilities.

The start
An MIT graduate with both engineering and start-up experience, Eric Fitch, PurposeEnergy’s founder and CEO, developed a biological process to generate a biogas, which could then be burned to create heat and electricity instead of attempting to create electricity directly from a chemical reaction.  Eric found a new anaerobic digestion technology that allowed for a much higher conversion rate and dealt with high solids concentration brewery wastes.

The impact
Roughly, $120 million in biogas can be produced annually through anaerobic digestion of domestic brewer’s spent grain alone.  The output doubles when spent yeast and trub is included.  This waste stream represents a lost annual electrical capacity of about 2.5 billion kilowatt-hours, or 234,000 households annual electrical consumption, according to the U.S. Department of Energy. 

Michael Whelchel is managing partner of Watershed Capital, an investment bank connecting sustainable companies with sustainable capital. Whelchel can be contacted at michael@watershedcapital.com or through LinkedIn at linkedin.com/in/michaelwhelchel. For purposes of full disclosure, Watershed Capital does not represent PurposeEnergy.