If you thought flying couldn't get more uncomfortable, then sorry, you're wrong: it looks like United Airlines will start powering its commercial planes with fuel made from animal feces and fats.
According to the New York Times, the dung diesel is part of an initiative to reduce greenhouse gasses, in tandem with new restrictions on aviation emissions the Obama administration outlined earlier this month. UA's announcement also ties neatly with a planned press statement concerning its $30 million investment in California-based Fulcrum BioEnergy, one of the most prominent companies within the biofuel industry.
The fuel UA will soon use for its jets is comprised of 30 percent biofuel, and produced by the firm AltAir Fuels. AltAir's website features a handy-dandy primer that succinctly explains the science behind poop power.
AltAir's biofuel is produced in two stages. During the first phase, free fatty acid molecules and triglycerides (organic compounds formed by glycerol and fatty acid groups) are deoxyginated when introduced to hydgrogen and another catalyst, which in turn release H2O and carbon dioxide in the animal matter; a paraffin chain is also created, and goes through a bout of isomerization, which results in selective cracking in the second stage. This cracking reduces the length of carbon chains that are also produced by the separation, which in turn give way to a green naphtha (or green diesel) by-product, which is then recovered to use as a renewable, feces-based gasoline.
Taking composting to a new level (both atmospherically and metaphorically), United Airlines is testing out the earth-saving vats of poo power on four or five flights between Los Angeles and San Francisco, which seems more than appropriate, given California's reputation as a environmentalist haven.
All doody jokes aside, the UA's soon-to-be implemented use of biofuel as a standard operating practice is a total win-win situation. As mentioned above, it's a great way to reduce carbon pollution, and it assists airlines in halving the cost of jet fuel: as reported by Fulcrum BioEnergy, it takes less than one dollar to produce a gallon of biofuel, while UA apparently purchased fuel at $2.11 per gallon this past year.
Get all of your poop jokes out now because this is the future, my friends, and it's looking a lot more earth-friendly.