A team led by the University of Illinois (UI) has engineered sugarcane plants that produce 12% oil by weight—and expect to reach 20% in the future—which would provide 17 times the barrels of oil per acre as that produced by soybeans, currently the most common source of biodiesel.

Biodiesel from “oil cane” ultimately could reduce the cost of biodiesel production from $4.10 to $2.20 per gallon and provide additional environmental and economic benefits, they claim.

Sugarcane metabolism was altered to convert sugars into lipids for use in producing biodiesel. Image credit: Pixabay.Sugarcane metabolism was altered to convert sugars into lipids for use in producing biodiesel. Image credit: Pixabay. UI researchers led by crop scientist Stephen Long formulated the biofuel in response to the call from the Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) program for high-risk, high-reward projects that could develop new drop-in fuels for its PETRO program.

“We thought that if we could go back to the drawing board, we’d need a very productive crop. And we would also need something that could grow on land that isn’t being used intensively for food. We came up with sugarcane and sweet sorghum,” Long recalls.

His team altered sugarcane metabolism to convert sugars into lipids, or oils, which could be used to produce biodiesel. The natural makeup of sugarcane is typically only about 0.05% oil. Within a year of starting the project, the team was able to boost oil production 20 times, to approximately 1%.

Currently, the so-called “oil cane” plants are producing 12% oil, and the goal is to achieve 20%.

“If all of the energy that goes into producing sugar instead goes into oil, then you could get 17 to 20 barrels of oil per acre,” Long explains. “A crop like this could be producing biodiesel at a very competitive price and could represent a perpetual source of oil and a very significant offset to greenhouse gas emissions, as well.”

In their analysis, the team looked at the land area, technology and costs required for processing oil-cane biomass into biodiesel under a variety of oil production scenarios, from 2% oil in the plant to 20%. These numbers were compared with normal sugarcane, which can be used to produce ethanol, and soybean.

An advantage of oil cane is that leftover sugars in the plant can be converted to ethanol, providing two fuel sources in one. Oil cane has additional advantages that have been engineered by the team, including increased cold tolerance and more efficient photosynthesis, which leads to greater biomass production and even more oil.

The analysis showed that oil cane with 20% oil in the stem, grown on underutilized acres in the southeastern United States, could replace more than two-thirds of the country’s use of diesel and jet fuel. This represents a much greater proportion than could be supplied by soybean, even if the entire crop went to biodiesel production. Furthermore, oil cane could achieve this level of productivity on a fraction of the land area that would be needed for crops like soybean and canola, and it could do so on land considered unusable for food crop production.

The current full production cost of biodiesel from soybean is $4.10 per gallon. Using oil cane instead, that cost decreases to $3.30 per gallon for 2% oil cane and to $2.20 per gallon for 20% oil cane. The ethanol produced from 1%, 5% and 10% oil cane would add to the cost benefit.

Although $2.20 per gallon does not represent a large savings over the current price of gasoline in the United States, Long cautions consumers and politicians to look at the bigger picture.

“We know from our past experience that it’s not going to last,” he says. “We need to start building for a future when gas is no longer as low as $1.50 per gallon, and we need to avoid any future dependency on other countries for our oil. We are lucky to have the land resources to do this and, in doing so, to ensure that future generations have a supply of oil that is domestic and renewable.”

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