Alternative Fuel: Coal-Burning Airliners?

An Air Force B-52H bomber gets the seal of
approval to burn synthetic fuel.
Photo: United States Air Force
The U.S. Air Force has just completed testing and approving an interesting alternative fuel, a man-made synthetic, for use in its huge eight-engine Boeing B-52H bombers. The next military airplane to be certified for the synfuel will be the Boeing C-17 cargo and troop carrier, essentially an Air Force airliner. Since fuel costs and availability are the biggest operating considerations for an airline, "We are being watched by many of our airline colleagues who are not only partnering with us but researching our data," says secretary of the Air Force Michael Wynne.
A zoomy new piece of high technology? Not at all. The jet fuel is made using a process called Fischer-Tropsch, which was originally developed in Germany in the 1920s and used by the Luftwaffe during World War II, when gasoline was in short supply. South Africa also made extensive use of Fischer-Tropsch during the dark days of apartheid, when the country was shunned by oil-exporting nations.
The Fischer-Tropsch process is basically a way of gasifying coal or natural gas and then refining the product into a high-quality, low-sulfur synthetic kerosene. (The nice thing about jet engines -- turbines -- is that they can be made to run on just about anything that'll burn, from hair tonic to whiskey. The hard part is making sure the fuel works at temperature and altitude extremes.)
Here's the not-so-good news:
As with ethanol, today's flavor-of-the-month alternative fuel, the Fischer-Tropsch process uses far more energy to make the synfuel than there is in the fuel thus created.
Because the U.S. has huge reserves of both coal and gas, it indeed helps to free us from dependence on the Middle East (which is essentially why the Air Force likes it, just as the Luftwaffe did). But according to the National Renewable Energy Laboratory, greenhouse-gas emissions created from the time the process starts to manufacture a gallon of synthetic jet fuel until the resulting fuel is consumed are nearly twice as high as what a gallon of petroleum-based jet fuel would create.
One answer might be to apply the Fischer-Tropsch process to biomass -- corn, sugar, potatoes, grass, whatever -- which will also work, though at the eventual cost of carpeting the country with veggies.
There are no easy answers to our insistence on instant, constant, unlimited energy.













coal will not be powering airliners: the coal to liquids industry is waiting for the most massive taxpayer subsidy of just about any energy industry in history: what they're asking FAR exceeds the "per gallon" subsidy of ethanol or biodiesel.
Coal to liquids fuels are a commercial flop in the making. Ask yourself: why are wall street financiers, in a market with historically high oil prices (and expectations for continued high prices) refusing to fund these coal to liquids projects?
The answer is quite obvious: they DON'T MAKE COMMERCIAL SENSE without these massive subsidies.
There most definitely are biofuel options, second generation especially, that have disruptive potential for aviaiton.
google around and you can see. watch developments over the next year, much progress on the aviation biofuel front to come....
Posted by: fiosole | August 15, 2007 at 10:55 PM