The case for camelina-derived aviation biofuel: Sustainability underpinnings from a holistic assessment approach

This study performed a holistic assessment of a novel cracking alternative (olefin metathesis or OMT) that converts plant oil to aviation biofuel using lipids from Camelina sativa L. (camelina). A high-resolution spatially explicit life cycle assessment and technoeconomic analysis (HR + LCA + TEA) was employed to elucidate camelina' s sustainability case. The potential camelina land was determined via the wheat-fallow Integrated Rotational Cycle (IRC) at county level for the 48 lower states in the U.S. Results revealed these lands were aggregated on the top wheat producing states of Montana, Kansas, and North Dakota at 19.5 x 10(6) ha, 18.2 x 10(6) ha, and 19.2 x 10(6) ha, for 2009, 2012, and 2015, respectively. If the high producing wheat lands (counties with >60,000-80,000 ha) in those states were grown with camelina at U.S. average yield of 1.2 Mg/ha, around 6.35 million m(3) (1.68 billion gal) of advanced biofuel will be produced, equivalent to 11.18 % of the expanded Renewable Fuel Standard (RFS2) volume mandate for advanced biofuel (15 billion gal). LCA results using 1 MJ functional unit and "well-to-air" (WTA) system boundary showed that the operations cumulative energy demand (CED) for the OMT case producing simultaneous biojet, avgas, and diesel was 0.75 MJ/MJ, lower than for hydroprocessed renewable jet (HRJ) fuel (0.77 MJ/MJ) but 6.8 times higher than for petroleum jet (PTJ) fuel (0.11 MJ/MJ). The entire OMT energy demand was offset by the bioelectricity produced (0.57 MJ/MJ) from burning the meal. OMT' s net GHG reduction relative to PTJ was 23.34 % but increasing camelina yield from 1.2 to 1.8 Mg/ha increased reduction to 75.71 %. TEA results adapting 100,000 m(3)/yr biofuel throughput showed that OMT and HRJ had profits of $21.94 M and $24.13 M, respectively, using mass product allocation. The limiting metric for OMT and HRJ was net present value (NPV), and the minimum camelina yield to ensure profit was 1.18 Mg/ha. OMT can achieve maximum profit by selling biojet fuel at a price not lower than $2.75/gal and selling camelina meal feed pellets at a minimum price of $330/Mg. No tax incentive was needed for biojet and avgas because even at their base median values (biojet = $2.19/gal, avgas = $2.59/gal), NPV is still positive.