Now, new research by scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) is claiming that plant-based bio-jet fuels could offer a competitive alternative to fossil fuels.
"It's challenging to electrify aviation using batteries or fuel cells in part because of the weight restrictions on aircraft, so liquid biofuels have the potential to play a big role in greenhouse gas emissions reductions," said lead author Corinne Scown, a researcher in Berkeley Lab's Energy Technologies Area as well as DOE's Joint BioEnergy Institute (JBEI).
"The team at JBEI has been working on biological routes to advanced bio-jet fuel blends that are not only derived from plant-based sugars but also have attractive properties that could actually provide an advantage over conventional jet fuels."
Optimizing each stage
JBEI multidisciplinary teams are hard at work seeking to optimize each stage of the bio-jet fuel production process from developing ideal source plants to obtaining the highest possible yield from bioconversion. Scown and her co-authors further used novel analysis methods to assess whether their goal of making plant-based fuels competitive to petroleum ones could succeed.
"Our hope is that early in the research stages, we can at least simulate what we think it would look like if you develop these fuel production routes to the point of maturity," Scown said.
"If you were to push them to the ethanol benchmark -- the technology to create ethanol from plant material like corn stalks, leaves, and cobs has been around a long time, and we can ferment sugars with a 90 percent efficiency -- how close would this get us to the market price of petroleum fuels? That is important to know now.
"Thankfully, the answer is they can be viable. And we've identified improvements that need to happen all along the conversion process to make that happen."
Reaching a target price
The efforts of JBEI have seen the theoretical cost of bio-jet fuel reach a mere $16 per gallon. That same gallon was an exorbitant $300,000 when JBEI was established. Still, there is some way to go as the cost of standard jet fuel is about $2.50 per gallon.
The researchers used computer simulations to model five paths featuring the necessary technology and subsequent costs of scaled-up production necessary to reach that target price. They found that all five pathways could indeed create plant-based fuels at a rate of $2.50 per gallon.
"The development of plant-based compounds that have a performance advantage over their petroleum-based counterparts is an important factor in determining their marketplace viability," said Blake Simmons, a co-author and the Chief Science and Technology Officer at JBEI.
The study is published in the journal Energy & Environmental Science.