Engineers at University of Wisconsin-Madison have found a way to convert 95% of the energy of cellulosic biomass into jet fuel using stable, inexpensive catalysts, basic equipment and minimal processing. The end hydrocarbon product is so similar to jet fuel that it is ready for application by present internal engine designs.
The team's previous research had focused on processes that convert plant-based sugars into transportation fuels, however they found that sugar molecules commonly degrade to form levulinic acid and formic acid which don't readily transform into high-energy liquid fuels.
Adopting a new approach they decided instead to exploit this process and began with the two products levulinic acid and formic acid as their platform. They found that in the presence of metal catalysts the two acids react to form a product called gamma-valerolactone (GVL). Using laboratory-scale equipment and stable, inexpensive catalysts, Dumesic's group converted aqueous solutions of GVL into jet fuel.
While other ethanol or cellulosic-based fuels have low energy density and cannot fully replace petroleum-derived hydrocarbons due to present internal engine design, "the hydrocarbons produced from GVL in this new process are chemically equivalent to those used in the present infrastructure," says Alonso. "The product we make is ready for the jet fuel application and can be added to existing hydrocarbon blends, as needed, to meet specs."
Not only that but the simple process preserves about 95 percent of the energy from the original biomass, requires little hydrogen input, and captures carbon dioxide under high pressure for future beneficial use.
In fact the only limitation to production of the cellulosic biofuel is the availability of cost-effective GVL which is currently manufactured in small quantities as an herbal food and perfume additive. But the team are already working on that too, and aim to develop more efficient methods for making GVL from biomass sources such as wood, corn stover, switchgrass.
Barely a week goes by that scientists aren't lauding a new biofuel but commonly the drawbacks are expensive components, unsustainably polluting byproducts compared with minimal energy profit and the problem of growing the biomass crop on land that would be better used for food production.
Ethanol-based biofuels jostle with cellulosic biofuels,and bacteria-farmed biofuels to find the answer as scientists hope that replacing gasoline with biofuel derived from processed waste biomass could see global emissions cut by 80%. This fuel could be closer than any of them to striking the right balance.
James Dumesic, Steenbock Professor of Chemical and Biological Engineering at UW-Madison led the team consisting of Jesse Bond and David Martin Alonso, both postdoctoral researchers, and graduate students Dong Wang and Ryan West. Dumesic and team published details of the advance in the Feb. 26 edition of the journal Science.
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