Forum: Technology

Flying the Coal-Fired Skies
The Air Force has an ambitious plan to wean American aviation off oil. But will the cure be worse than the disease?

In the not-so-distant future, cars could run on electricity, power plants on wind and solar energy, and city buses on zero-emission hydrogen fuel cells. But airplanes? Those just might run on coal.

Yes, coal. The U.S. Air Force wants to create a synthetic-fuel industry that, unless something better comes along, will mine America’s massive coal supply (we have more than a quarter of the world’s known reserves) and turn it into enough jet fuel for half its domestic operations to run on a 50/50 blend of synthetic and regular fuel by 2016. By the Air Force’s logic, it has no choice. It uses more fuel than all the other branches of the military combined, burning through 2.5 billion gallons of the stuff in 2007 alone—10 percent of the total used by the entire domestic-aviation fuel market—at a cost of $5.6 billion. And although oil prices have dropped in recent months, no one expects the relief to last indefinitely.

Source: http://www.popsci.com/node/31142

Coal to Liquids (CTL)

The production of liquids from coal requires the breakdown of the chemical structures present in coal through the simultaneous elimination of oxygen (O), nitrogen (N) and sulphur (S) and the introduction of hydrogen (H). This action produces a stable liquid product. Coal can be converted into a variety of products including petrol, diesel, jet fuel, plastics, gas, ammonia, synthetic rubber, naptha, tars, alcohols and methanol. There has been extensive research into converting coal to a liquid, but there are basically three approaches, pyrolysis (direct method), hydrogenation (direct method) and gasification and synthesis (indirect method).

CTL technology was developed in the early 20th century and was used in Germany in the 1930's and 1940's. Since 1955 in South Africa, the SASOL company has operated the only CTL plant in the world to date. However, the Senhua Group expect a CTL plant to start in late 2008 at Ordos in China. In Australia from 1955 to 1969, a Lurgi gasification plant produced gas for the Melbourne market from briquetted Yallourn brown coal. From 1985 to 1990 a Japanese consortium operated a CTL pilot plant at Morwell which demonstrated that hydrogenation of La Trobe Valley brown coal was technically feasible.

Underground Coal Gasification: Syngas can also be produced by underground or in-situ coal gasification. In this method fuel gases are produced underground when a coal seam gets enough air to burn but insufficient for all consumable products to be consumed. Carbon dioxide, carbon monoxide, hydrogen and methane are produced to yield a gas of low but variable heat content. Air is pumped into the burning coal bed through a well, and the gas is drawn off from a point behind the fire-front through another well. A problem is the collapse of the coal bed and subsidence on the surface. The gasified coal can then be used to produce liquids or electricity. The power station at Angren in Uzbekistan has the only operating underground coal gasification project in the world.

The JP-8 fuel is what the US Military uses in all of its jet-powered aircraft and on average accounts for nearly 70 percent of the DoD's $8.5 billion fuel budget-a steep bill that is based completely on petroleum.

http://www.popsci.com/node/31142

Air Force drops plan to make fuel from coal in Montana

The Air Force on Thursday dropped plans to build a coal-to-liquid plant to produce fuel for its aircraft, a plan that would've reduced dependence on oil but increased the emissions of the heat-trapping gases that cause global warming.

The Air Force has a goal to certify that all aircraft could fly on a 50-50 blend of fuel by 2011. It's been purchasing fuel made from coal from Sasol of South Africa , most recently 300,000 gallons, said Air Force spokesman Gary Strasburg.

Source: http://news.yahoo.com/s/mcclatchy/20090 ... /3156444_1

What a load of BS. Coal-to-liquid is a great way to get us off of foreign oil and this time the USAF took the lead, but as usual the damn global warming nutjobs shut it down.

How are we supposed to stop paying the Saudis if we never do anything that is not 100% green?

I sure hope we can learn to turn coal into jet fuel