Sensitive to aviation as a source of greenhouse gasses, Continental says it’s finishing up testing that will make HVO or hydrotreated vegetable oil a fuel option in its CD-100 series engines. There are three engines in the line, the CD-135, -155 and -170. All three are currently approved to use Jet-A.
The company gave no date for the final approval of HVO, but bio-derived fuels are a growth industry for the diesel engine segment. HVO is made by hydrocracking vegetable oils using hydrogen rather than the methanol used to produce biodiesel. It can be made from a variety of feedstocks, ranging from waste fats, tallow and cooking oil or virgin energy crops such as jatropha, palm oil and soybeans. Algae can also serve as a feedstock. HVO emits slightly less carbon dioxide in the burning than petroleum diesel does—as much as 15 percent. But its total lifecycle emissions are 50 to 90 percent less than petroleum diesel because the fuel is returning to the atmosphere carbon already absorbed during the plant growth cycle.
Worldwide, HVO production is growing, although its market share is small. HVO and biodiesel are similar, but HVO is less carbon intensive because it contains no petroleum constituents. Biodiesel is called R-99 or green diesel because by federal law in the U.S., it must contain 1 percent petroleum-derived diesel. The U.S. is the largest producer of true HVO, but the market remains underdeveloped in the U.S. R-99 biodiesel accounts for about 2.3 billion gallons of 68 billion gallons produced. Biodiesel is currently between 70 and 130 percent more expensive than fossil diesel.
To the user, HVO fuels will be no different than Jet-A. “Our extensive analysis has thus far demonstrated results that confirm our 4-cylinder Jet-A engines exhibit seamless performance equal to traditional Jet-A,” said Dr. David Dörner, vice president of global research and development for Continental.
Diamond Aircraft is also pursuing alternative fuel approval for the Austro engines used in its aircraft. Rather than HVO, Diamond is testing sustainable aviation fuel (SAF). It hasn’t announced any results yet.
“the fuel is returning to the atmosphere carbon already absorbed during the plant growth cycle.”
Where did the (evil) carbon in fossil fuels come from if not from the atmosphere? The only difference is the timeframe. Fossil carbon was removed eons ago, while HVO (non-fossil) carbon was removed last summer.
“But its total lifecycle emissions are 50 to 90 percent less than petroleum diesel because the fuel is returning to the atmosphere carbon already absorbed during the plant growth cycle.”
I agree – this is just a “sleight of hand” magic trick (skillful deception), probably from the Washington administration. It is still spewing out carbon dioxide, no matter how you look at it.
> Fossil carbon was removed eons ago, while HVO (non-fossil) carbon was removed last summer.
And that timeframe difference matters.
If the fueler chooses a litre of petroleum fuel, and the fuels industry refines more petroleum fuel to backfill, then in that timescale, the carbon for a litre’s worth of petroleum fuel started off in the ground, and ends up in the atmosphere. But if the fueler chooses a litre of HVO, then by the time industry backfills that litre, the carbon for a litre’s worth of HVO started off in the air and ended up in the air — and the carbon which would have made the backfill petroleum fuel remains in the ground.
IDK. Still seems wrong to me. If the source is something that normally gives up it’s CO2 somewhat quickly so that our refining it is simply releasing something that was going to be released shortly anyway, then I can see those numbers. But I can’t think of anything like that.
On the other hand, if that CO2 would be stored in the top soil until someone plowed it or did something else, then I don’t see that there is really that much savings. We are adding CO2 that nature was going to store for a long time.
Besides that, at some point, I don’t know where, there’s bound to be an issue with cracking oil to get other products we need becoming less carbon efficient because much of it is currently done as a byproduct of gas and diesel refining, right?
I’m not an expert on any of this, but I’ve gotten untrusting of either side in the CO2 debate.
“Biodiesel is currently between 70 and 130 percent more expensive than fossil diesel…To the user, HVO fuels will be no different than Jet-A.”
Ah, to be the user instead of the payer…I miss Uncle Sam’s gas card.
Yes, most carbon in petrochemicals came out of the atmosphere … largely in the Mesozoic Era ~200 million years ago. Release it by burning and you get that atmosphere back along with those 10 deg C higher global average temperatures.
But a CO2 molecule is a CO2 molecule. Could you look at my thought above and tell me where I’m going wrong? I’m thinking that on average, the cycle of say switch grass carbon release and recapture is measured in decades or centuries. Am I wrong?
My point exactly. Which atmosphere do you want to bring back?