The global aviation industry uses a whole lot of fuel: more than 5 million barrels a day. It is an incredibly energy-intensive industry and almost all of its energy comes from petroleum-based fuels.
While other large energy sectors such as electric power, ground transportation and commercial buildings have well-defined pathways to adopting renewable energy sources, the aviation industry does not have such a straightforward way to make a transition to sustainability. Electrifying planes using batteries or fuel cells is very challenging for a number of reasons, notably the weight restrictions on aircraft. So liquid biofuels as replacements for petroleum-based fuels remain the most promising approach.
A new study at the Lawrence Berkeley National Laboratory concludes that sustainable plant-based biofuels could provide a competitive alternative to conventional petroleum fuels if current development and scale-up initiatives are successful.
Multidisciplinary teams based at the Department of Energy’s Joint BioEnergy Institute are focused on optimizing each stage of the bio-jet fuel production process. This includes bioengineering ideal source plants and developing methods for efficiently isolating the carbohydrates in non-food biomass that bacteria can digest and bioconvert into fuel molecules.
The critical issue is cost. The theoretical cost of bio-jet fuel has come down dramatically in recent years but is still around $16 a gallon. The cost of standard jet fuel is about $2.50 a gallon. So, the real challenge is bridging that gap.
Reducing the cost of the fuel could come both from the material and process improvements that are underway as well as by finding ways to turn the leftover lignin residuals from the bioconversion process into valuable chemicals.
Photo, posted March 28, 2009, courtesy of Yasuhiro Chatani via Flickr.