Researchers Developing Machinery To Harvest Corn Stalks And Leaves

…development of a stover harvesting system has been constrained by a lack of research funding.

“Significant resources have been dedicated to the process of converting cellulose into ethanol,” he said. “But very little has gone into answering how do you get a supply of stover from the field to the biorefinery. This will be critical to the success of the bioeconomy.”

Although tests with the prototype machine have been successful, Birrell said there is more development work to do:

Harvest capacity. The stover harvesting equipment is capable of speeds equal to a normal grain harvest when less than 50 percent of the stover is collected. When all of a field’s stover is collected, harvest speeds are about half of a normal grain harvest. Birrell said that would be unacceptable to farmers. And so he’s working to get the speed to at least 80 percent of a normal grain harvest — no matter how much stover is collected. That would allow farmers to decide how much stover they want to harvest without significantly affecting the time it takes to harvest their fields.

Transportation. Birrell said researchers need to figure out how to pack the harvested stover so it can be economically transported. He said stover comes off the combine at a density of about 3 to 4 pounds per cubic foot; it needs to be about 10 to 12 pounds per cubic foot for efficient trucking.

Storage. Birrell said researchers need to figure out how huge quantities of biomass can be stored. He said the U.S. Department of Energy has estimated a biorefinery would need at least 2,000 tons of biomass per day. A year’s supply would cover 100 acres with 25 feet of biomass.

Fertility. Birrell said researchers need to determine how much stover can be removed from fields while still returning sufficient organic matter to the soil and protecting the soil from winter erosion.

Science Daily