China Lake Researchers Develop Potential Biobutanol Pathway for Synthetic Jet Fuel
29 July 2008
Researchers at the Naval Air Warfare Center Weapons Division (NAWCWD) at China Lake, California have developed an efficient batch catalysis process for the conversion of 1-butene (C4H8)—easily derived from butanol (C4H10O)—to a new class of potential synthetic jet fuel blends, with a specific focus on the requirements for the Navy’s JP-5. JP-5 has a significantly higher flash point (60°C) in comparison to the Air Force JP-8 and commercial jet fuel (~38°C).
The resulting product developed by the team of Michael Wright, Benjamin Harvey, and Roxanne Quintana is 100% iso-paraffinic, meets flash point and cold-flow requirements, and has a calculated power density (per volume) higher than similar fuels made by the GTL Fischer-Tropsch process. They report on their work in an ASAP paper published online 29 July 2008 in the journal Energy & Fuels.
The ultimate goal of our research program here at China Lake is to create a full-performance JP-5/tactical biojet fuel that can be derived from a fully renewable and sustainable source of reduced carbon. Given recent advances in the conversion of starch and cellulosic biomass to biobutanol, we have initiated a program to explore using the C4 alcohol as a pivotal and versatile starting point for the creation of new fuels. Because both butyl ether and 1-butene can be easily derived from 1-butanol, we are investigating use of these chemicals as precursors to biojet fuels that will meet the required energy content and key performance specifications of JP-5 jet fuel. In this paper, we present methods for converting 1-butene into a variety of useful saturated hydrocarbon fuels using a highly efficient batch-catalysis process.
The new approach affords a product that is composed of 100% iso-paraffins, retains good fuel density, possesses attractive cold-flow properties, and, critical to Naval applications, can be easily tailored to have a high flash point.—Wright et al. (2008)
The process entailed condensing the 1-butene onto CaH2 and then transferring it over the course of 3 hours to a chilled (dry ice bath) pressure reaction vessel containing activated catalyst—bis(cyclopentadienyl)zirconium dichloride in the presence of methylaluminoxane (MAO). The reaction vessel is sealed and allowed to react with stirring at ambient temperature for 16 hours. The result is the consumption of the 1-butene and the production of dimers and oligomers.
The produced product makes incremental jumps in 4-carbon units—i.e., C8 (dimer), C12, C16, C20, C24, C28, and C32. The dimer—about 25 wt.% of the product mixture—is removed for separate conversion to C16 compounds for reblending with the end product. Hydrogenation (~0.08 wt% PtO2/H2, 2 psig) of the remaining oligomers yields a fuel that has a flash point of 59°C, viscosity of 103 cSt, and a lubricity value of 0.45 mm. By changing the catalyst preparation, they produced a significant change in oligomer distribution, while still maintaining full conversion of 1-butene to oligomers.
In summary, we have developed a highly efficient batch catalysis methodology for conversion of 1-butene to a new class of potential jet fuel blends. By tuning the catalyst and then using the dimer produced, we can bring the carbon use to ~95% or greater. This latter point will be particularly important in the future, where the source of raw materials (i.e., biomass/biofeedstock) is limited. Also noteworthy, the batch catalysis approach herein requires a minimal input of energy and hydrogen to make fuels that possess useful flash points, coldflow properties, and solution density/energy content. This new process affords a saturated hydrocarbon fuel that has a high solution density and thus possesses a higher calculated power density (per volume) than similar fuels made by the GTL Fischer-Tropsch processes.—Wright et al. (2008)
Michael E. Wright, Benjamin G. Harvey, and Roxanne L. Quintana (2008) Highly Efficient Zirconium-Catalyzed Batch Conversion of 1-Butene: A New Route to Jet Fuels. Energy & Fuels ASAP Article 29 July 2008 doi: 10.1021/ef800380b
I assume that "high carbon use" means coal can be used with minimal co2 production. Does "minimal energy input" mean cheap?
I understand that this is meant to be a biofuel but the article hints at the use of coal.
Posted by: d burgdorff | 29 July 2008 at 04:15 PM
These military labs around the country are great resources to tap into for biofuel research.....as is evident by the top-quality material presented here. The more help the better.
Posted by: ejj | 29 July 2008 at 06:16 PM
This a fairly complicated path indeed, to make biobutanol in the first place is not that easy, so far you need a bacteria which makes the process more complicated than using yeast lilke for ethanol, then transforming it into jetfuel will unavoidably result in more losses.
Posted by: Treehugger | 29 July 2008 at 07:34 PM
I didn't even see the word coal in the article, just Fisher Tropsch, and then it was just used as a comparison to FT not "hinting" at using coal. everything I read was bio related. (Even though coal is actually biorelated, just like oil, but I digress with what bio actually means)
I agree completely
Did you miss the "highly efficient" part of the summary, or the "efficient" part of the batch process in the first sentence of the article
Having been in the military for 14 years, private sector for 5, and the education sector for 13, please let me inform everyone out there, compared to any other operation I've ever been associated with, the military is the absolute model of efficiency. It would have been nice to see some conversion efficiencies though so we could make our own conclusions
Posted by: cokemachine | 30 July 2008 at 07:43 AM
"we can bring the carbon use to 95% or greater. This latter point will be particularly useful in the future, where the source of raw materials (i.e. biomass/biofeedstock) is limited."
This suggests the use of coal to me. Given the amount of fuel consumed by the military and its desire to be free of foreign dependance, it's natural that coal would be considered in addition to biomass. I'm sure the commercial aviation industry would be interested.
Under the 2007 Energy bill the military can only use synthetic fuel if it does not result in increased release of CO2.
If this can be done economically it would be an incredible benefit to our economy.
Posted by: d burgdorff | 30 July 2008 at 10:45 AM
It is great to see the military taking energy supplies for defense purposes very seriously. They're very motivated, and I suspect they will be a big player in tranforming our energy portfolio.
Use electricity for short-range transport and rail, biofuels or even (gasp!) H for ships and planes, and whatever possible for defense.
Long-term national security is one reason I DO NOT support much additional offshore drilling in the US. Let's use up every one elses oil first and/or move to new energy sources and save our remaining oil for when we really need it 50 or 100 years from now.
Posted by: JustinVP | 30 July 2008 at 11:00 AM
I am a event producer. Last year, I put together a CTL event where Assistant Secretary of the Air Force, William Anderson(who by the way resigned Monday over the Chinese fuse and nuclear war head flown over US debacle). He spoke about the Air Force full intent to integrate CTL and Biomass type fuels into the Air Force fuel supply chain. They are currently working with the Gov. of Montana to build a CTL pilot plant at a decommissioned air base. These plants will cost in the billions to build. I'm currently working on another CTL summit. It will take place in November. This year there seems to be major resistance to CTL based on my speaker recruiting efforts. This hearing sums up the current obstacles to CTL in the US:
I not a proponent of CTL but through my job have learned much about the industry.
Posted by: Sully | 30 July 2008 at 03:23 PM
Because I believe we need to be completely off of oil well before 50 years from now I'd rather use our own oil and keep the $700 billion we're sending to other countries.
Posted by: d burgdorff | 30 July 2008 at 04:09 PM
Arguably, one of the best things that is happening in the world right now is China & Russia are becoming dependent on oil. This weakens OPEC's influence around the world - especially on the US. If we can launch a Manhattan Project to get off foreign oil - maybe Russia and China will wind up fighting the next oil war(s) in the future!
Posted by: ejj | 31 July 2008 at 07:52 AM
Glad to hear about the progress in catalysts. The US Military is not about to get caught without fuel as long as the world is so rife with pirates, bandits, and rogues.
Coal makes a fine liquid fuel, or a fine gas-for-fuel. But you can get butanol from biomass using multiple micro-organism colonies in serial bioreactors.
Posted by: Alfred P Slofinator | 03 August 2008 at 08:01 AM