Why an Atlanta startup is betting on hemp bricks to offer cheaper SAF
Cultiv8 aims to revolutionise sustainable aviation fuel economics by offsetting costs with carbon-negative construction materials.
As the aviation industry grapples with the high cost of sustainable fuels, Atlanta-based startup Cultiv8 has proposed an unconventional solution: hemp-based fuel subsidised by construction materials. The company believes this approach could eventually produce renewable jet fuel at prices below conventional fuel.
The company's model uses revenues from carbon-negative hemp bricks – which it plans to sell to commercial construction firms as a sustainable building material – to offset fuel production costs. If successful, this strategy could address two critical hurdles facing the sustainable aviation fuel (SAF) industry: high costs and subsidy dependence.
Breaking the cost barrier
Traditional SAF producers typically command a premium of two to five times the price of conventional jet fuel, making widespread adoption challenging without substantial government support. Cultiv8 claims its approach could upend this economic model, though this remains to be proven at a commercial scale.
"Unlike companies that only produce fuel, when we produce our fuel, we also create hemp bricks," says Steven Fance, CEO and CTO of Cultiv8.
"Each tonne of hemp used in construction effectively locks away 1.25 metric tonnes of carbon dioxide, making these bricks increasingly valuable in carbon-conscious construction markets. The revenue from these bricks would allow us to sell our sustainable aviation fuel at a discount to fossil jet fuel."
This proposed cross-subsidisation strategy would distinguish Cultiv8 from other companies in this sector, which need to rely on government incentives to help bridge the green premium.
The company believes its independence from subsidies could prove crucial as uncertainty surrounds the future of the Inflation Reduction Act. While established producers watch political developments, Cultiv8 maintains its business model would remain viable regardless of policy changes.
The approach also aims to address another critical industry challenge: the food versus fuel debate that has long plagued biofuel producers. Unlike corn-based alternatives or companies that rely on food-chain-linked products like cooking oil, Cultiv8's hemp feedstock would operate entirely outside the food supply chain.
"Hemp reaches maturity in just 90 days, and we can get two harvests annually in southern states," Fance explains. "It actually helps increase yields of other crops when used in rotation, creating a win-win for farmers and food production."
From lab to runway
While Cultiv8 reports it produced its first diesel products in testing in 2021 at its Lake Charles, Louisiana facility, it is not producing commercial aviation fuel yet. Full-scale production is expected to begin when new Lake Charles and Macon, Georgia facilities come online in 2027.
Let’s put the scale of the company's ambitions in perspective. Delta Air Lines, for example, uses 4 billion gallons of fuel yearly. Cultiv8 says they could supply all of it. The catch? They'd need 10 million acres of hemp farmland. That's an area the size of Vermont and New Hampshire combined.
While this might sound unrealistic, Fance points out that U.S. farmers currently manage over 895 million acres of farmland, and hemp's ability to serve as a rotational crop means it could be integrated into existing agricultural operations rather than requiring dedicated land.
Overcoming the cannabis association
However, challenges remain, particularly around hemp's complicated history. Despite its legalisation in 2018, the industry has faced scepticism from financial institutions and investors. "It took a long time for us even to open up a bank account," Fance acknowledges.
"Banks were uncomfortable just banking with a company that uses hemp as a feedstock material. When seeking infrastructure funding, we constantly have to educate people that this is industrial hemp, completely different from cannabis," says Fance, noting that hemp was once so mainstream that the U.S. Constitution was made out of hemp before the material was made illegal in 1937.
This lingering misconception about hemp extends beyond banking. The company, Fance explains, dedicates significant time to educating investors, customers, and partners about hemp's industrial heritage and its distinction from marijuana.
The science behind the solution
In terms of technical approach, rather than using biological processes to convert feedstocks like used cooking oil, Cultiv8's planned process involves heating hemp in the absence of oxygen (pyrolysis) to create synthetic gas, which would then be converted to liquid fuel through the Fischer-Tropsch process. This technology has been used to produce synthetic fuels for almost 100 years.
Beyond aviation, Cultiv8 is targeting multiple markets with hemp-derived products, including renewable diesel, natural gas, and green hydrogen. The diversity of products would help support the company's economics while addressing various sectors' sustainability needs.
The next few years will be crucial as Cultiv8 attempts to prove its business model at commercial volumes. If successful, it could represent one solution to sustainable fuel economics, offering a path to widespread adoption without requiring government support or premium pricing.
Fance sums up his company's key selling point more directly:
"No other startup, no other big oil company can say that they can literally decarbonise Delta Airlines affordably while helping farmers."