Tuesday, November 13, 2007

Fischer-Tropsch and Jet Fuel Research

Recently, there seems to be quite a bit of news around aviation grade biofuels. Primarily the highest profile being Virgin Atlantic Airlines and The U.S. Department of Defense (see Syntroleum).
A biofuel meeting jet fuel specifications is starting to become a holy-grail technology of sorts. On par with ethanol produced from corn-stover. There is a very simple argument that a bio-jet fuel can be classified as a paradigm shifting technology. That if perfected would allow one of the largest energy uses in the first world economies to leap frog beyond petroleum.

The big stumbling block to this paradigm shifting concept is the low tolerances required to operate a plane a mile in the sky. If you can make a jet fuel, as the logic goes, you now can make any fuel. The scale, scope and specifications required offer up aviation as the pinnacle of what a biofuel must be to truly arrive on the world stage.
Essentially its pretty simple. If there is a fuel problem while airborn, as we used to while I worked as a flightline refueler in the Air Force, the crew has the rest of their lives to figure it out. Being the solution development time in this situation is minutes instead of the typical "five years out" a DOE grant holder gets away with the stakes become a little higher.

These are the constraints of aviation fuels (commonly called either Jet-A or the military nomenclature of JP-8). A biofuel/syn fuel must operate at extremely varied altitudes and temperatures (typically -30 degrees Fahrenheit and lower). It must store well and be predictable when aging (i.e. we must be able to give it a shelf life and quality assurance system). The fuel also must have better emissions than petro-Jet A, a similar cost per Btu, and of course the basic consistency regardless of the feedstock the fuel is derived from. You also have specification constraints as well to operate in existing jet turbine engines (i.e. it must look like Jet-A to existing engines; this being expressed typically in specific gravity, cetane, ingrained water content, etc.....).

Enter good old Fischer-Tropsch as the hoped solution. With a product typically called "syn-diesel" this technology is proven but expensive. It also pulls a consistent product out of such feedstocks as coal, agricultural waste, solid waste, and just about anything with a significant Btu content. So like most issues of energy, the issue becomes who can commercially demonstrate the better iteration of a technology invented by old dead Nazis.

A story covering the basics of this ongoing endeavor of the search for a bio-aviation-fuel popped up this morning. Check it out in the Aviation International News online.

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