Developing research shows that lignin seems to have the capability to be used to make 100% sustainable aviation fuel. An untapped renewable environment might be precisely what the aviation sector requires to cut carbon dioxide emissions.

Scientists from three institutions, the U.S. The National Renewable Energy Laboratory (NREL), the Massachusetts Institute of Technology (MIT), and Washington State University recently presented the findings in utilizing lignin as a road forward toward a drop-in 100% renewable aviation fuel. Lignin makes up the stiff sections of plant cell walls. Other plant elements are utilized for bioenergy, but lignin has generally remained disregarded due to the difficulty in chemically breaking it down and turning it all into usable chemicals.

This latest published study revealed a procedure created by scientists to extract oxygenation from lignin such that the resulting compounds may be used at a different concentration level for aviation fuel. The observations were just released in the journal Joule.

Aviation Fuel Pollution Gradual Reduction

Because the airline sector has vowed to dramatically decrease carbon dioxide emissions, the report underlines the need of choosing sustainable jet sources of energy. Throughout 2019, aircraft used 106 billion jet fuel gallons globally, a quantity that is expected to even more than triple by 2050. To realize the industry's goal of net emissions reduction beyond that period, significant implementation of environmentally friendly aviation fuels (SAF) with high mix restrictions with conventional energy sources would be essential.

Aviation fuel is a complex combination of petroleum hydrocarbons, including aromatics as well as cycloalkanes. Existing marketed methods do not create the materials required for a 100% SAF. SAF blendstocks are instead blended mixed traditional hydrocarbon fuels. As nature's most abundant source of renewable aromatics, lignin may hold the key to developing a fully bio-based jet fuel.

Their latest released study demonstrates how a lignin route might supplement current and emerging systems. The lignin route outlined in this new paper, in particular, permits the SAF to be compatible with fuel systems at greater mix percentages. Lignin is often burnt for heat and electricity or employed in low-value properties due to its resistance, according to NREL's report.

A potential sustainable aviation fuel.
(Photo : National Renewable Energy Laboratory)
Containers are of poplar biomass (left), the extracted lignin oil, and the resulting sustainable aviation fuel.

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Earlier Research Supporting Possible Aviation Fuel

Prior studies have obtained lignin fluids with significant oxygen concentrations that tend to range from 27% to 34%, but to be utilized as aviation fuel, that proportion must be lowered to less than half-percent.

Several methods of reducing oxygen concentration have been attempted, however, the catalysts used need costly transition metals and therefore have shown to be poor yielding. Scientists from the three schools devised an effective approach that employed earth-abundant molybdenum carbide as a catalyst in a continuous cycle, obtaining an oxygen saturation of roughly 1%.

This discovery was financed by the US Department of Energy's Bioenergy Technologies Office as well as the Center for Bioenergy Innovation. NREL is the U.S major national laboratory of the Department of Energy for energy efficiency and renewable energies development and research.

SAF has been used on over 450,000 flights, with over 100 million liters generated in 2021. SAF has the potential to cut emissions by anywhere from 80% throughout its entire lifespan. According to the International Air Transport Association, over 17 billion US dollars of SAF are under forwarding purchase agreements in 2022, and more than 50 airlines currently have SAF expertise.

IATA partner airlines as well as the aviation sector as a whole have committed to aggressive emissions reduction targets. Sustainable jet fuel has been considered to be among the critical components in achieving these objectives. The use of sustainable aviation fuels is critical to meeting the industry's climate targets.

RELATED ARTICLE: Oxford Scientists Convert Carbon Dioxide Into Carbon-Neutral Jet Fuel

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