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Sweetening corn

Renville, Minn. — Could sugar beets sweeten corn ethanol manufacturing?

Minnesota beet farmers hope the answer is “yes,” when a study sponsored by AURI’s Center for Producer-Owned Energy is completed. The study being conducted for the Southern Minnesota Beet Sugar Cooperative will determine if adding sugar during fermentation speeds up ethanol production. The research could benefit both the corn and sugar beet industries by boosting ethanol plant efficiency and offering a new use for excess beet sugar.

The Southern Minnesota Beet Sugar Cooperative was founded in 1972 by about 300 sugar beet growers. Today its 584 farmer-shareholders operate 12 beet-receiving stations in southwest Minnesota. The cooperative employs about 350 full-time workers during the beet-processing season and an additional 320 during the fall harvest.

The co-op’s Renville refining factory has the capacity to produce 400,000 tons of sugar a year. That’s about 30 percent more volume than it is allowed to market at federally-supported prices. Growers are looking for new outlets for the excess sugar, says Dennis Timmerman, AURI project director.

Laboratory tests, which will evaluate 2- to 7-percent sugar concentrations in corn mash, will start this summer at Greenway Consulting in Morris, Minn. If lab results look promising, the cooperative will do several plant-scale tests at a Minnesota ethanol facility.

The co-op will also evaluate the economics of using its excess sugar for ethanol. Under current federal trade quotas, Timmerman notes, the extra sugar is worth considerably less than it costs to produce. Timmerman emphasizes that sugar beet growers are not seeking to displace corn in ethanol production. Rather, he says, the goal is to improve the efficiency of corn-ethanol manufacturing — in effect increasing the capacity of the state’s ethanol plants.