Continental, taking environmental concerns seriously, is concluding testing to include hydrotreated vegetable oil (HVO) as a fuel option for its CD-100 series engines. The CD-135, CD-155, and CD-170 engines are currently approved for Jet-A use.
While a specific approval date for HVO was not provided, bio-derived fuels have been gaining popularity in the diesel engine segment. HVO is produced through hydrocracking vegetable oils with hydrogen, instead of the methanol used in biodiesel production. It can be made from various feedstocks, including waste fats, cooking oil, jatropha, palm oil, soybeans, and even algae. HVO emits slightly less carbon dioxide during combustion compared to petroleum diesel, up to 15 percent. However, its total lifecycle emissions are significantly lower, ranging from 50 to 90 percent less, as the fuel releases carbon that was already absorbed during plant growth.
Globally, HVO production is on the rise, although it still holds a relatively small market share. Unlike biodiesel, HVO contains no petroleum constituents, making it less carbon-intensive. The United States is a prominent HVO producer, while the market for true HVO remains underdeveloped in the country. R-99 biodiesel, which contains 1 percent petroleum-derived diesel by federal law in the U.S., accounts for approximately 2.3 billion gallons out of the 68 billion gallons of biodiesel produced. Currently, biodiesel is between 70 and 130 percent more expensive than fossil diesel.
From the user's perspective, HVO fuels will be indistinguishable from Jet-A. Dr. David Dörner, vice president of global research and development for Continental, confirmed that their 4-cylinder Jet-A engines demonstrated seamless performance similar to traditional Jet-A during extensive analysis.
In a similar pursuit of environmentally friendly fuels, Diamond Aircraft is exploring alternative fuel approval for its Austro engines, with sustainable aviation fuel (SAF) as the focus. As of yet, Diamond has not released any results regarding its SAF testing.
