Biotechnology for aviation biofuels – new studies focus on life cycle analysis
Posted on 22/05/2017
One study compared well-to-wake greenhouse gas emission performance of a selection of conversion technologies for sustainable aviation fuel compared to fossil fuel. The study found, in order of greatest GHG emission:
Fischer–Tropsch (86–104%) Hydrothermal Liquefaction (77–80%) Sugarcane (71–75%) Corn stover-based Alcohol-to-Jet (60–75%)
The main contributors to GHG emission performance relate to: feedstock cultivation, hydrogen and conversion inputs. You can read more here.
A second study looks at the GHG emissions of four alcohol-to-jet technologies compared to petroleum jet fuel: Ethanol-to-jet (ETJ) from corn; ETJ from corn stover; Sugar-to-jet (STJ) from corn stover via biological and catalytic conversion.
The study found that the feedstock is the main factor in Well-to-Wake GHG emission performance of ETJ: corn- and corn stover-based ETJ are estimated to produce GHG emissions of 16 and 73%, respectively, compared to petroleum jet.
STJ via biological conversion may generate GHG emissions 59% below those of petroleum jet. STJ via catalytic conversion could reduce the GHG emissions by 28% using H2 from natural gas steam methane reforming or 71% with H2 from biomass gasification than those of petroleum jet. You can read more here.
A third study examines the techno-economic analysis of three ATJ pathways using sugarcane, corn grain and switchgrass. The study incorporates technical uncertainty for all by-products and co-products through statistical linkages between conversion efficiencies and input and output levels. Future price uncertainty is based on case-by-case time-series estimation and includes breakeven price distributions.
The study found that sugarcane is the lowest cost feedstock over the entire range of uncertainty with the least risks, followed by corn grain and switchgrass, with the mean breakeven jet fuel prices being $0.96/L ($3.65/gal), $1.01/L ($3.84/gal), and $1.38/L ($5.21/gal), respectively.
The variation of revenues from by-products in corn grain pathway can significantly impact its profitability. You can read more here.