The cost of producing biofuel from eastern red cedar in Oklahoma

Encroachment of eastern red cedar (Juniperus virginiana) has reduced the forage productivity of North American Great Plains grasslands. The objective of this study is to develop and demonstrate a modeling system that can be used to determine the breakeven price of biofuel when using biomass from invasive eastern red cedar as the exclusive feedstock for a fast pyrolysis process biorefinery used to produce gasoline and diesel blend stock. A mixed integer mathematical programming model is constructed and applied to a 15-county case study region from which eastern red cedar may be collected. The modeling system considers the growth rate of unharvested trees, enables determination of the proportion of biomass inventory required, determines the optimal biorefinery location, the optimal harvest locations for each of 20 years, and the breakeven biofuel price. To fulfill 2000 Mg per day feedstock requirements for the expected life of the biorefinery, 73% of the trees growing in year zero in the case study region would be required. For a 313 L Mg-1 conversion rate, and with biorefinery ownership, operating and maintenance cost of $0.63 L-1, the expected cost to deliver feedstock is estimated to be $61 Mg-1, and the estimated breakeven biofuel price is $0.83 L-1