Powering jets with fuel made from mustard plants could slash carbon dioxide emissions by up to 68 percent, according to a new study.
Researchers at the University of Georgia found Brassica carinata, a non-edible seed crop, could be grown and processed into oil in the U.S. and wind up being cheaper than current petroleum-based airplane fuel, if proposed sustainable-fuel tax credits are approved.
The aviation industry emits 2.4 percent of all carbon dioxide emissions worldwide, according to the Environmental Energy Study Institute and is responsible for 3 percent of the US’s total greenhouse gas production.
Currently, though, sustainable aviation fuel (SAF) only accounts for about 0.05 percent of the roughly 50 billion gallons of jet fuel consumed each year.
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Brassica carinata, a non-edible seed crop, can be grown and processed into oil to be used as biofuel for airplane engines. Switching to the mustard green would lower carbon emissions by up to 68 percent, according to researchers
‘If we can secure feedstock supply and provide suitable economic incentives along the supply chain, we could potentially produce carinata-based SAF in the southern United States,’ Puneet Dwivedi, a professor of Sustainability Sciences at the university’s Warnell School of Forestry and Natural Resources, said in a statement.
Using the mustard plant-derivative in the gas tank would lower the industry’s carbon footprint ‘while creating economic opportunities and improving the flow of ecosystem services across the southern region,’ Dwivedi added.
Currently, petroleum-based aviation fuel costs rightly 50 cents a liter, while producing SAF from carinata ranges from 12 cents to $1.28 per liter.
With proper economic incentives, the mustard fuel would come away much cheaper in the end.
In 2018, a Qantas jet completed a 15-hour transpacific flight using a biofuel made with 10 percent oil derived from carinata — saving an estimated 20 tons in carbon emissions
A chart indicating the carbon generated from growing and processing from sustainable aviation fuel made from carinata
In September, President Biden proposed boosting SAF nationwide with a sustainable fuel tax credit that would require a 50 percent reduction in life-cycle carbon emissions.
Carinata exceeds that threshold, according to the team’s research, published in the journal GCB Bioenergy.
Airplane engines capable of running without fossil fuels are being planned for 2025, though current plans can theoretically run on a 50-percent sustainable blend.
The U.S. Department of Agriculture has invested $15 million to investigate how to grow carinata stateside.
Dwivedi, who has been involved in the project, says it can be grown as a ‘fallow’ crop during the mild winters in Southern states like Alabama, Florida and Georgia, home to Hartsfield-Jackson Atlanta International Airport, one of the world’s busiest air hubs.
A rendering of the life cycle of carinata-based sustainable aviation fuel
‘Since carinata is grown in the ‘off’ season it does not compete with other food crops, and it does not trigger food versus fuel issues,’ he said in the release.
As a ‘cover crop,’ carinata would also slow soil erosion from runoff from rainfall and snowmelt, he said.
Carinata can be pressed and used as fuel within a day of harvesting. After crushing the seeds and extracting the oil, the residue can be ground into feed for cattle. Critics say biofuels drive up prices on food and is damage the environment in other ways
The plant can be pressed and used as fuel within a day of harvesting and after crushing the seeds and extracting the oil, the residue can be ground into feed for cattle.
IS BIOFUEL BAD FOR THE ENVIRONMENT?
Environmental groups have often rejected proposals to make biofuels out of food sources such as corn or on land that could be used for food.
While biofuel might sound good on paper, researchers have found that instead of using fossil fuels to inject eons-old carbon into the air, it recycles carbon from the atmosphere.
In practice the research points to a much more negative impact on the environment.
Increases on global food prices have a high toll particularly on the urban poor in developing nations, researchers found.
Here the price of food staples can represent a third or more of total household spending. Even small increases then have a significant impact on people’s welfare.
A 2017 report from the Royal Academy of Engineering found biofuels made from food crops leads to more emissions than those produced by fossil fuels.
The academy warned that clean biofuels such as algae are still far off.
The most frequently used types of biodisesel are palm oil, soybrean, rapeseed and sunflowers, all of which are more polluting than diesel.
‘It’s a tough crop. It grows where other crops won’t grow. It doesn’t need much water and it’s well understood by farmers,’ Steve Fabijanski, CEO of biofuel corporation Agrisoma, said in a statement in 2018. ‘They can grow it and do well with it.’
One drawback is plant-based fuels require more land to develop: In 2018, Qantas completed a 15-hour transpacific flight from the U.S. to Australia using 6,000 gallons of a biofuel blend with 10 percent derived from carinata.
That saved an estimated 20 tons in carbon emissions, but it took up 150 acres of land to create the SAF, an area larger than the Vatican City.
A 2017 analysis developed by BirdLife International argued that demand for biofuels made from food crops has led to an increase in global food prices and is damaging the environment.
But the Biden administration is eager to wean aircrafts off fossil fuels as part of the White House’s broader push to lower aviation emissions 20 percent by 2030 and achieving a fully zero-carbon aviation sector by 2050.
Its strategy would rely heavily sustainable aviation fuel (SAF), like carinata, as well as cooking oil and animal fat.
A source told Reuters in August that ‘discussions are still in the early stages,’ but the administration has confirmed SAF is at the top of its list as a replacement.
Also In August, the United Nations’ Intergovernmental Panel on Climate Change (IPCC) released a bombshell climate assessment suggesting the Earth is likely to warm by 2.7 degrees Fahrenheit within the next 20 years — a decade earlier than previously expected.
Heatwaves, flooding and droughts will become more frequent and intense as a result, according to the IPCC assessment.
President Biden has proposed major investments ‘to propel innovation and deployment of sustainable aviation fuels,’ Ali Zaidi, deputy national climate advisor for the White House, told Reuters.
‘The administration is committed to advancing climate solutions in every sector and segment of the economy – with the urgency that the climate crisis demands.’
HOW MUSTARD PLANTS ARE CONVERTED INTO JET FUEL
After the Brassica carinata plant is harvested, its seeds are removed and crushed to release carinata oil.
When pressed, the seeds yield half their weight in oil, which is then requires a minimal amount of refining to be used as jet fuel, according to AGFax.
‘Farmers can grow carinata with the same equipment as wheat and canola, and it can be grown in the off-season to replenish field nutrients,’ Steve Fabijanski, president of biofuel firm Agrisoma said in 2018, when Qantas used carinata in a biofuel mix to fly from the US to Australia.
‘And while they produce a high oil content, the meal left over from the oil extraction is an excellent high-protein feed for livestock,’ Fabijanski said.