Green Jet Fuels

Popular Mechanics journal ran a story recently on green jet fuels (Air Force Holds Throttle on Future of Green Jet Fuel by Basem Wasef, September 17, 2008). A nice summary of the overall developments:

The U.S. Air Force cites environmental concerns, energy security and energy independence among its reasons for adopting synthetic fuel technology, but the real reasons seems to be excessive price of oil in the future.

Consumption levels of synthetic fuel are identical to standard fuel, but synthetics burn more cleanly, as their sulphurless composition produces less soot and particulate matter. Maintenance is reduced because combusted fuel leaves fewer engine deposits. The fuel leaves thinner contrails, offering visual evidence of the fuel's cleaner burn characteristics. But the process does produce carbon dioxide during manufacturing and when it burns.

Former Air Force Secretary Michael Wynne spearheaded the agency's investigation into alternative fuels in 2005 by creating an 11-member task force. Just a year and a half later, a B-52 Stratofortress flew out of Edwards Air Force Base on 50 percent standard-issue military JP-8 fuel and 50 percent Synthetic Paraffinic Kerosene fuel derived from natural gas. (Unlike petroleum products, the synthetic fuel lacks aromatics, preventing it from being used in ratios greater than 50 percent.) The B-52 was the perfect candidate for testing, since its eight engines offer ultimate mechanical redundancy; the first flight was performed with only one engine using synthetic fuel, so that if the engine failed there would be seven backups.

Though the process of validating and testing synthetic-fuel blends continues within Air Force and civilian circles, its future is fraught with question marks. At least for the time being, the Air Force has been sourcing its natural gas-derived fuel from the Shell Corporation in Bintulu, Malaysia. (The U.S.-based Syntroleum Corporation, which supplied fuel for the B-52 flight, completed research and limited production at a pilot plant for synthetics but won’t open a full-scale facility until early 2010.) The Air Force will also be sourcing 5000 gal. of synfuel from Rentech in Colorado. The magazine was quick to make the following correction.

UPDATE: The original version of this story referred incorrectly to the state of alternative-fuel supplier Syntroleum Corp., which closed down a pilot facility in Catoosa, Okla., in September 2006—not the entire company’s operations—after successfully “perfecting their process” of synthetic fuel production, according to a Syntroleum spokesperson. Earlier this year, the company received state approval and funding for its first full-scale plant in Geismar, La., which is scheduled to begin production in 2010.

Watch the exclusive video of the flight from the Air Force.

Popularmechanics ran another story along the similar lines ( 5 Clean Jet Fuels to Wean Planes Off Oil, By Chris Ladd, September 17, 2008). Below is a some important parts including my additions:

Airlines spent $25 billion more on fuel last year than the year before, and they're expected to spend $50 billion more than that—$183 billion—by the end of 2008.

Coal
The Air Force is turning over 700 acres of base in Montana for a plant that will turn solid coal into liquid fuel. Coal-to-oil, while more expensive than petroleum-based fuels, is a domestic alternative. However, coal-to-oil fuel is not the most environmentally friendly of oil's possible replacements. The process produces carbon dioxide, a greenhouse gas, but advocates claim CO2 capture and sequestration could be possible (especially if mandated by the government). An analysis by the U.S. Department of Energy's Argonne National Laboratory in 2007 found that this fuel, even after using carbon capture and storage techniques during creation, would still produce at least 20 percent more carbon dioxide than petrol and diesel made from oil.
Biofuel

Richard Branson’s Virgin Atlantic performed a flight test with Boeing 747 using bio-fuel made from coconut oil from London to Amsterdam on an 80/20 mix of standard jet fuel to biofuel made from coconut and babassu oil. Air New Zealand is expected to test a mixture of biofuel derived from jatropha, a Central American plant, in the coming months, with plans to use at least one million barrels of "sustainable" fuels in the company's aircraft per year by 2013. Critics have been skeptical—reactions to Virgin's flight cited minimal reductions in carbon emissions and possible future complications as fuel feedstocks compete for space with food crops or rainforest.

Algae
The yield of oil per acre is many times that of other feedstocks; it has the ability to thrive in dirty, brackish water, and it is capable of turning pollution from power plants or sewage treatment facilities into clean fuel. And while commercial quantities of algal oil don't yet exist at the commodity prices necessitated by the airline industry, heavyweights like Boeing and Airbus are already investigating powering tomorrow's jets with the stuff. Airlines Jet Blue, KLM, Virgin and others are also scrambling to make a viable fuel from the slime. DARPA, the Pentagon's advanced projects agency, has also funded research to refine a replacement for JP8 jet fuel from feedstocks like algae, hoping for a cheaper, cleaner, domestically produced fuel to help gas up.

By the way USAF is also interested in Algea (see Biofuel research could result in alternative energy source) .Air Force-funded biofuel researchers are investigating ways to produce large quantities of hydrogen gas using photosynthetic microbes, commonly known as algae and cyanobacteria. In large quantities, the hydrogen gas could function as a renewable, cheap and clean energy source for future military systems.

Designer Hydrocarbons
Yeast and bacteria have been producing ethanol for millennia, but a bunch of startup companies are genetically engineering the microscopic organisms to metabolize sugars into hydrocarbons—including jet fuel. Researchers are able to fine-tune the exact length of the hydrocarbon chains that the organisms produce, yielding finished fuels chemically identical to those derived from petroleum. San Francisco–based LS9 is at work on a pilot facility, while fellow Bay Area company Amyris is setting up shop in Brazil, where it plans to turn some 2 million tons of sugar into commercial quantities of diesel, gasoline and jet fuel by 2012. And while today's bugs only thrive on simple sugars, future advances in technologies that break down cellulose could open up the potential to convert anything that grows into a source of feedstock.

Solar
Last month, the British-made QinetiQ Zephyr set the record for the longest unmanned flight of any kind—82 hours and 37 minutes—powered by nothing more than sunlight. The craft operated off solar-charged batteries at night. A Swiss psychiatrist is currently at work developing a solar-powered plane to take himself and a co-pilot around the world in 2011. He made a similar journey in a propane-powered hot-air balloon in 1999. With the plane's average speed is planned to be just 42 mph, the craft is hardly set to shake up the industry. The real future of solar-powered planes is likely in HALE-UAVs (High Altitude Long Endurance Unmanned Aerial Vehicles) such as the Zephyr—providing long-term environmental monitoring or surveillance.

If you want to watch some videos here are some from the US Air Force:

Synthetic Fuels - Video Story from USAF

Green Energy - Video Story from USAF

My thoughts on green fuels have not changed: They are expensive, not that green, doesn't improve USAF mission capability, add extra burden to taxpayers, but good business for military-industry complex.