Researchers at the University of Illinois are making progress in the continual effort to develop sustainable and cost-effective processes for harvesting and collecting biomass feedstock.

Alan Hansen, a professor in agricultural and biological engineering (ABE) at the University of Illinois, is part of a team working with the Energy Biosciences Institute (EBI) to determine the main obstacles in current processes and equipment that could limit their application in biomass feedstock harvesting.

“Part of our work is to assess how well existing equipment functions and what modifications we need to make to this equipment to ensure that it can handle miscanthus harvesting adequately,” said Hansen.

“These machines are generally set up to harvest crops like hay and forage. There is some degree of uncertainty related to these machines working in miscanthus, which is a much denser, taller crop, or even switchgrass, a shorter grass.”

Harvesting traditional crops is generally a two-pass process, said Hansen. The mower/conditioner cuts the crop, feeds it to a set of rolls that crimp and mash the cut material, and then lays it on the ground in windrows. The baler makes a second pass to pick up and bale the material.

“In some of our earlier work with miscanthus, the mower/conditioner was not set up well,” said Hansen, “so after the miscanthus stems were cut, instead of being mashed up, they came straight out the back, all lined up, and it was difficult for the baler to pick up that material.”

Hansen said they experimented with a sickle mower as well as a disk mower. “We eventually chose the disk mower because the through-put is much greater,” he said. “But there were challenges with that in that you have an auger that propels all the cut material to the center of the head to then feed it out the back.

“The auger wasn’t doing a very good job of picking up these long stems after they were cut. So they had to add some fingers and vanesto help with that process. They also changed the size of the auger in order to help propel the material more efficiently into the center of the machine.”