State study uses corn, soybean alternatives to process ethanol
Editor's Note: This is the second in a four-part series this week on the renewable fuel industry. Tomorrow, learn about a Luverne man's experience growing miscanthus for ethanol production.
WASECA -- Minnesota is known as a row crop state, and all one needs to do is take a drive through the countryside to see acres upon acres of corn and soybeans growing in the summer sun.
Years ago, the state's corn and soybean crops were fed to livestock, and what wasn't used was hauled away by truck, rail or ship for further processing into breakfast cereals, cooking oils and other goods.
Farmers looked at those export shipments as lost revenue, and when value-added became a buzz word in the 1980s, the movement began to develop renewable fuels from renewable resources. In the last two decades, ethanol plants -- and later biodiesel refineries -- cropped up across Minnesota's landscape to capture more money for the farmers who plant the seeds and till the soil. Adding value to Minnesota's corn and soybean crops has, in essence, boosted the economies of rural communities throughout the state.
Yet, as farmers and processors reap the benefits of renewable fuels, there are some Minnesotans who aren't content to think corn and soybeans are the end-all for renewable fuel production.
At the University of Minnesota Southeast Research and Outreach Center in Waseca, Gregg Johnson is leading a biomass study that involves growing bushy willow and poplar. The goal of the research is to develop a method to extract cellulose from the plants that can be processed into ethanol.
"What we're really interested in is serving multiple benefits," Johnson said. "We want to provide raw product for ethanol or feed, but we want to do it in a way to address environmental issues such as erosion, nitrate leeching and storing water, so we don't have as much going into our lakes and streams."
By planting willow or poplar in strategic areas of the landscape, Johnson said landowners can help improve the environment and, at the same time, play an active role in the production of renewable fuel.
The University of Minnesota began researching woody biomass a couple of years ago, when a company looked at Waseca as a possible site to burn woody trees for the production of steam and electricity.
"That thing fell through, but they were very interested in willow," Johnson said. "We started growing both willow and poplar and looking at the agronomic components of those plants."
In the last two years, considerable amounts of research dollars have been invested just on the engineering phase to extract cellulose for ethanol production. As those questions are being answered, Johnson said other issues such as growing needs and habits, fertilizer needs and weed control have taken a back seat.
The University of Minnesota, however, isn't the only educational institution researching willow and poplar. Johnson said their researchers work with the State University of New York (SUNY) College of Environmental Science and Forestry at Syracuse, specifically on the willow project, while the poplar research is coordinated with the Natural Resources Research Institute (NRRI) of Duluth. In addition to willow and poplar, the research center in Waseca is testing the biofuel potential of alfalfa, corn stover, False Indigo and switchgrass.
With the abundance of corn in the Midwest, some might argue there isn't a need to bring other alternatives into the mix for ethanol production.
To the contrary, Johnson said a speaker at a seminar he recently attended claimed that only 25 percent of the nation's corn crop could be used for ethanol production before it would start impacting the food market.
"It appears there's kind of a limit to corn being used for liquid fuel," Johnson said. "With this tremendous demand that is coming, we need to find other sources of raw material for ethanol production."
Woody biomass, he believes, could be the answer.
"Woody biomass ... has complex sugars and yields a lot more sugars than a corn plant," Johnson said. "You just have to work to get at those sugars."
Another reason Johnson sees potential in the woody crops is location. There are some areas where corn simply won't grow very well -- areas where willow or poplar could thrive.
At the research center, Johnson said workers are planting bushy willow in a high-density, twin-row system. The trees are planted in 6-inch cuttings, allowed to grow through the summer and then cut to create six to eight new shoots to come up in the spring. Once established, Johnson said the willow can be harvested after three years, with plants re-establishing themselves for up to a 20-year period. Poplar, on the other hand, are left to grow for about five years before harvest.
As for harvesting the wood, Johnson said SUNY has created a harvester that is similar to a forage chopper with a modified head. The contraption chips the wood and blows it into a trailer, and from there the process begins to extract the cellulose.
The research center in Waseca has several acres of willow and poplar that are involved in a variety of ongoing experiments. The first harvest of willow will take place this fall, with poplar harvest starting next year.
The results of those harvests will include information on which varieties grow best in Minnesota's climate, and which are most productive in cellulose.
Johnson said the technology of extracting sugars from woody biomass is within a year or two of being completed. Even then, it could be years before farmers are actually planting willow and poplar for ethanol production.
"The industry has to take the technology and develop the plants and the infrastructure," he added. "Our goal here is we want to be able to have that basic information on how to grow this biomass, so when the opportunities come along to locate a plant in the state, we can make it more feasible for them to supply the materials for the plant."
In the two years since research began on woody biomass in Waseca, Johnson said they've learned quite a lot about willow and poplar production. Among the biggest challenges are weed control -- there aren't the variety of herbicides available that there are for corn and soybeans -- along with the cost of establishing the plants and then harvesting them after three years.
"There is a pretty significant up-front cost of establishing the material, but if you spread that over 20 years, it becomes negligible," Johnson said.
Aside from ethanol production, Johnson said the plants could become more profitable as people find uses for the co-products.
"You're producing compounds that can be used to develop plastics and other uses," he added.