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United States Department of Agriculture

Agricultural Research Service

Research Project: Production and Conservation Practices to Maintain Grass Seed Farm Profits Title: On-farm conversion of straw to bioenergy – A value added solution to grass seed straw

Authors
item Mueller Warrant, George
item Banowetz, Gary
item Whittaker, Gerald
item El Nashaar, Hossien

Submitted to: Seed Production Research at Oregon State University
Publication Type: Experiment Station
Publication Acceptance Date: March 1, 2010
Publication Date: March 31, 2010
Citation: Mueller Warrant, G.W., Banowetz, G.M., Whittaker, G.W., El Nashaar, H.M. 2010. On-farm conversion of straw to bioenergy – A value added solution to grass seed straw. Seed Production Research at Oregon State University. 139:25-30.

Interpretive Summary: Knowing the location of straw from grass seed and cereal production in the PNW is vital for feasibility studies comparing scales of operation of proposed bioenergy conversion plants. Because existing data on straw availability were limited to county-wide summaries, our first step was to map the location of all grass seed and cereal production in the PNW using satellite images. Analysis of the spatial distribution of straw from grass seed and cereal crops across the PNW indicates that bioenergy conversion plants of 1,100 tons per year capacity should be able to obtain needed straw from within a radius of a very few miles, opening up the possibility of using farm-scale equipment such as forage choppers, wagons, silage blowers, and bunkers to handle the straw from the field to the syn-gas generator. The economic advantages of not needing to bale and truck the straw long distances will at least partially offset efficiencies of scale likely present in large plants operating at 100 or more times the capacity of the farm-scale unit. For larger sized plants, the distance required to collect straw generally increased as the square-root of the increase in plant capacity for the first 80% of all possible plants.

Technical Abstract: Knowledge of the geospatial distribution of straw from grass seed and cereal production in the PNW is vital to the accuracy and reliability of feasibility studies comparing scales of operation of proposed bioenergy conversion plants. The first step in identifying optimum locations for straw-based bioenergy conversion plants was to map the location of all grass seed and cereal production in the PNW using remote sensing methods. Individual year estimates and multi-year averages of available straw were then used in procedures that identified the optimal locations for each new bioenergy plant, based on local density of straw and location of all previously sited plants. Each new plant was sited at the position of the maximum straw density over a neighborhood adequate to supply all the straw needed for plants with capacities of 1 million, 10 million, and 100 millions kilograms per year, after removing straw needed for previously sited plants. Analysis of the geospatial distribution of straw from grass seed and cereal crops across the PNW indicates that optimally sited bioenergy conversion plants of 1 million kilograms per year capacity should be able to obtain needed straw from within a radius of a very few kilometers, opening up the possibility of using farm-scale equipment such as forage choppers, wagons, silage blowers, and bunkers to handle the straw from the field to the syn-gas generator. The economic advantages of not needing to bale and truck the straw long distances will at least partially offset efficiencies of scale likely present in large plants operating at 100 or more times the capacity of the farm-scale unit.

Last Modified: 11/28/2014
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