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Using it all

Jack Johnson and Al Doering know how to use leftovers. Turning vegetable peels into fertilizer, wood fibers into mulch, and cow manure into electricity are just a few of their specialties.

Johnson is engineering director and Doering a technical service specialist at AURI’s coproducts utilization program in Waseca, which includes a laboratory and pilot plant. Originally called the waste utilization program, the name now reflects a commitment to using all the byproducts of production and processing. “It is no longer the mentality that you make one product and throw everything else out — it all has value,” Johnson says.

The staff get requests from entrepreneurs, businesses and ag groups wanting to take advantage of the plant’s mixers, extruder, dryer, pellet mill and grader. Demand is so high they have had to turn down requests. “We have 12 active projects in full-scale product or process development,” Johnson says. He and Doering are named on two patents and have three more pending.

Not all projects focus on byproducts — a few use raw commodities. For example, the Waseca technical staff helped Pet Care Systems in Detroit Lakes, Minn., redesign its wheat-based cat litter to clump better, produce less dust and work in automatic litter boxes. They refined and validated the product and are listed as inventors on the new patent.

Projects involve horticultural products, livestock feed and renewable energy, Johnson says. He and Doering typically make test products, analyze them, change formulations and do trial runs in the pilot plant. They produce reports for clients detailing analysis results and remaining issues to be addressed.

The most exciting area right now is renewable energy, consuming “40 to 50 percent of our time,” Johnson says. The Waseca staff work on generating power from solids such as cow waste for electricity and ag processing waste for heating fuel.

For example, Minnesota “leads the country in corn stoves,” Johnson says. “There are three to four manufacturers currently and several emerging.” As an alternative to corn, “we’ve been blending and pelletizing coproducts.” The applications range from home heating to major industrial use.

One project involves Hill Wood Products in Cook, Minn., which burns sawdust to provide energy for U.S. Steel (see story page 15). “Iron mines have been using wood fuels for years but as wood is coming into short supply, we’re bringing ag crop residues into the mix,” says Johnson, who has been characterizing the Btu content of various ag materials. “Ag residues could be used in place of wood or natural gas or propane; it’s cleaner than coal.”

The Waseca staff has spent considerable time investigating anaerobic digesters, which turn methane from cow manure into electricity. They’re speaking at energy seminars around the state on the digesters’ potential to power communities. They were also involved in bringing a 50-megawatt poultry litter power plant to central Minnesota.

Future coproduct uses that could reap substantial profits include medicinal nutrients from soybean hulls and specialized sugars and proteins from pulp waste.

While AURI-funded projects are always accompanied by technical assistance, about half of Johnson’s and Doering’s projects receive technical assistance alone. The team prefers to help medium and small companies, but large companies can offer opportunities to utilize high quantities of byproducts.

“The most satisfying part of the job is to assist companies and businesses working with rural Minnesota, the lifeblood of our state, and seeing them be successful — a feed mix in a bag or ag commodities turned into fuels. … What we’re offering are things we can do best.”