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Biomass Energy DSystems Project update

Principal Investigators

  • Stephen Long
  • Madhu Khanna
  • Gary Letterly
  • Linda Smith

Harvest, Transport and Processing.

In April of 2007, the miscanthus and switchgrass plots which are located on the Dudley Smith farm were harvested by Eric Denton, a local custom baler from Pana, IL with the bales stored until September. In September, the bales were shipped to Springfield, IL for pre-processing at Evans Recycling. The processed material was then shipped to Mt. Pulaski products in Mt. Pulaski, IL for pelleting.

As there was not a single processing location for the baled material, the pelleting process was more intensive than originally anticipated. Furthermore, the processed material that was delivered to the pellet mill was not ground finely enough, and therefore the pellets tended to crumble more than would be ideal. Since that time, we have given more baled material to pre-processors to see if they are able to grind it finely enough. Also, the pellet mill operators believe that much of the horsepower that they use in their normal processing can be bypassed in this particular operation.

As soon as the field conditions are acceptable, the miscanthus and switchgrass plots will be harvested this year and we will attempt to work out some of the processing issues from 2007. We plan to cooperate with the same groups in 2008 to work out the kinks in the processing. The costs of these processes will be documented for use in economic analysis.

Combustion

In February of 2008, the biomass furnace that was purchased for installation at the Christian County Extension Office was completed and operational. As this furnace was designed for corn grain, there were some technical issues with burning grass pellets. We are currently cooperating with Mel Repshar of Taylorville, IL from whom we purchased the furnace to optimize the combustion of the pellets.

In the winter of 2008/2009, the furnace will be used to heat the Christian County Extension Office and monitored to determine the biomass usage and the costs will be documented for use in the economic analysis.

Field Trial Expansion

In collaboration with the Energy Biosciences Institute, in the spring of 2008, the miscanthus rhizomes from the plots which were planted in 2006 will be lifted using a mechanical rhizome harvester and planted on a 5 acre plot on or near the Dudley Smith farm. Furthermore, the plots from which rhizomes were harvested will be replanted on a closer row spacing to reach maximum yields. It is expected that this 5 acre plot plus the 2 acres of miscanthus and switchgrass from original trials will provide enough material to heat the Christian County Extension office each year.

Economic Analysis

To estimate the costs of using miscanthus for local heat generation, we are developing estimates of the costs of producing miscanthus at a 10 Km x 10 km scale for Illinois. GIS data on soil and climate were collected for each 10 km x 10 km grid and used to obtain the opportunity costs of converting land to miscanthus from corn and soybeans at various corn and soybean prices. We also develop preliminary estimates of the costs of producing miscanthus and switchgrass in each grid cell. These costs will be adjusted based on data we obtain from actual harvesting of the plots on the Dudley Smith Farm. Our earlier costs of producing miscanthus were developed at the county level and were in 2003 prices. We have now updated them to 2006 prices and extended them to a finer grid.

We will use this data together with actual estimates of the costs of pelleting these grasses to estimate the costs of delivered fuel for residential heating. Capital costs of installing the biomass furnace and energy used to achieve specified heating levels will be documented and used to compare the costs of heating with electricity or natural gas with those using bioenergy from miscanthus and switchgrass. Preliminary estimates suggest that there is a great deal of variability in the costs of producing these grasses and in the costs of land across different regions in Illinois. These costs are expected to be lower in southern Illinois than in central and northern Illinois. Additionally, current costs of pelleting grasses at $100 per ton are rather high. Preliminary estimates show that at these costs, grass pellets are more expensive than shelled corn for residential heating.

The outcomes of this research will provide valuable information about the technical and economic feasibility of a small scale miscanthus and switchgrass operation to produce dedicated biomass feedstocks for energy production. In the longer term, we hope that this project can be used to heat the Christian County Extension office at an annual cost which is competitive with traditional heating sources. This will serve as a research and education center to highlight the potential of sustainable, non-fossil based energy production in Central Illinois.