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AURI Staff Column Seeing Around Corners

For years, most businesses considered ag processing leftovers nothing more than waste. Now some of those businesses are looking at novel ways to capture revenue from those “waste” streams.

Here, at AURI’s coproduct utilization lab in Waseca, “waste” has been stripped from our vocabulary. Byproducts with low or even negative value now can become an additional revenue stream.

AURI provides support and expertise to evaluate opportunities for agricultural processing leftovers.

Biogas and biodigestion

A wide range of companies are interested in generating biogas through various technologies, including anaerobic digestion. Despite current low natural gas prices, many businesses are pursuing innovative ways to produce biogas. Fuel prices traditionally rise and fall. Rather than wait for critical situations, having technology and information in hand when natural gas prices rise again could make biogas more attractive.

Energy production is not the only reason anaerobic digestion systems are installed. Some enterprises, such as dairy farms, use digesters to manage manure. For agricultural processors, it could be an opportunity to use low or even negative-value products (those that have disposal costs) to produce something positive, like biogas.

AURI has experience with several anaerobic digestion projects. And we are developing our own digester, larger than bench scale, to test biomass and other materials for biogas potential.

Dewatering technology

Water is essential for life, but for most biomass applications, water is the enemy. Emerging dewatering technologies could drastically reduce biomass moisture, making it easier to handle. The new methods are cheaper than thermal drying.

Some efficiency claims made by dewatering system manufacturers have yet to be substantiated independently. However, if they are proven to be efficient and low cost, dewatering technologies could improve biomass combustion and gasification efficiencies and lower biomass transportation costs.

Drying technology

AURI has held several events for Minnesota processors, highlighting drying technologies that are currently available. Whether for an ethanol plant, food product manufacturer or feed processor, drying biomass material can be a significant expense. Finding an efficient system that matches the needs of a processor can improve material handling and save money. A report on these dryer events and the demonstrated technologies is available at

AURI will continue to evaluate and disseminate information to processors about drying technologies that could be applied to their operations. Processors and drying companies are encouraged to get involved through our on-line discussion board:


Handling and processing biomass — whether baling, grinding, pulverizing or pelleting — is important to any venture. AURI recently increased its capacity to support biomass granulation processes for developing products.

Much like AURI’s current pelleting capacity, AURI can now assist in developing granulation blends for fuel, fertilizer or other value-added applications. n

Kevin Hennessy is associate scientist for coproducts at AURI’s Waseca laboratory. He holds a master’s degree in biosystems and agricultural engineering from the University of Minnesota and a bachelor’s degree from Goshen College in Goshen, Indiana. Hennessy taught science, math and reading in Minnesota public schools for 17 years. He has been with AURI since 2008.