Cost to produce liquid biofuel from invasive eastern redcedar biomass

Abstract

Biomass harvested from invasive plant species has been proposed for use as lignocellulosic feedstock for the production of advanced biofuels as a way to mitigate the indirect land use issues associated with the production of dedicated energy crops. Encroachment of eastern redcedar (Juniperus virginiana L.) has reduced the forage productivity of North American Great Plains grasslands ranging from Texas in the South to Alberta in the North. The objective of this study is to develop and demonstrate a modeling system that can be used to determine the minimum selling price of biofuel. A fast pyrolysis process that exclusively uses eastern redcedar biomass to produce gasoline and diesel blend stock is assumed. A mixed integer mathematical programming model is constructed and applied to a 15 county case study region from which eastern redcedar may be collected. The modeling system considers the growth rate of unharvested trees to determine the optimal biorefinery location, the optimal harvest locations for each of 20 years, and the minimum selling biofuel price. To fulfill 2 Gg d−1 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 dm3 Mg−1 conversion rate, and with biorefinery ownership, operating and maintenance cost of 630 $ m−3, the expected cost to deliver feedstock is estimated to be 61 $ Mg−1, and the estimated minimum selling biofuel price is 830 $ m−3.