Naval Air Warfare Center awards contract to Albemarle for processing Cobalt Technologies’ bio n-butanol to renewable jet fuel using Alcohol-to-Jet process
|Overview of the NAWCWD alcohol-to-jet process. Source: NAWCWD. Click to enlarge.|
The Naval Air Warfare Center Weapons Division (NAWCWD), China Lake has awarded a contract to Albemarle Corporation to complete the first biojet fuel production run based on bio n-butanol provided by Cobalt Technologies. For this production run, Albemarle will use NAWCWD alcohol-to-jet (ATJ) technologies (developed by Michael Wright, Benjamin Harvey and Roxanne Quintana, earlier post) to process Cobalt’s bio n-butanol into renewable jet fuel at its Baton Rouge, La. processing facility.
Cobalt converts non-food feedstock such as woody biomass into renewable butanol for both chemicals and fuels, including jet fuel. The combined science team from Cobalt and the NAWCWD focused on scaling and optimizing the dehydration chemistry for the conversion of bio n-butanol to 1-butene, followed by oligomerization of the bio-butene into jet fuel, based on the process developed at NAWCWD in China Lake, CA. (Earlier post.)
|Alcohol to Jet|
|Alcohol is attractive as a feedstock for the production of renewable jet fuel partly because all the steps required are currently in use at commercial scale in the petrochemical industry. (Earlier post.)|
|The ATJ process broadly consists of four main steps: dehydration of the alcohol; oligomerization; distillation; and hydrogenation. Key to the cost-effectiveness of ATJ is reducing the production cost of the alcohol, as well as of the ATJ process itself.|
|Just as there are many types of crude oil that can be refined to produce petroleum jet fuel, and just as there are many types of feedstocks that can be used in Fischer-Tropsch and natural oil hydrogenation processes to produce renewable jet, so are there different alcohols produced by a variety of pathways and feedstocks that can be converted into renewable jet.|
|ATJ is one of the alternative jet fuel pathways being supported by the Federal Aviation Administration, and ASTM has formed an ATJ task force. (Earlier post.)|
Once the team completed its initial research, the search for a large-scale processing partner began, which resulted in the awarding of the contract to Albemarle. NAWCWD said that Albemarle was the only contractor that had the expertise, materials and facilities necessary to provide this large scale synthesis in the amount of time required. Specific production activities covered under the contract include:
Dehydration. Utilizing the reactor rig constructed in an prior stage of work, selective dehydration of bio-butanol to 1-butene shall be conducted utilizing a supplied catalyst operating at a temperature of approximately 380 °C. This step will occur in the High Pressure Laboratory (HPL) section of the Process Development Center (PDC) and will be performed over a duration of 1 week.
Butene Drying. The butene will be dried over molecular sieves, in a small packed bed set up. This shall be done in the HPL section of the PDC immediately following completion of the previous dehydration step and shall be performed over a duration of 1 week.
Oligomerization. Using a Ziegler-Natta type catalyst system that will be supplied by NAWCWD and activated at the PDC, for the oligomerization of 1-butene to the ethyl branched higher olefins. This step shall be conducted in the South Lab section of the PDC in a 30-gallon reactor system and will be performed over a duration of 1 week.
Stripping / Olefin Mixture Recovery. The dimer product 2-ethyl-1 hexene will be stripped out of the olefin mixture. This shall be done in a 30 gallon reactor system and shall be performed over a duration of 1 week.
Dimer Oligomerization. The recovered C8 liquor shall be treated with Dow Amberlyst-15 catalyst (protonated form, dry). This step shall occur in the High Pressure Laboratory (HPL) section of the PDC and will be performed over a duration of week.
Hydrogenation. The olefin mixture shall be hydrogenated to yield paraffins. A Raney Nickel catalyst system will be used. This step shall occur in the SPU-North section of the PDC in a 50-gallon glass lined steel reactor system and shall be performed over a duration of 1 week.
Distillation. The paraffins shall be vacuumed and distilled to remove C28 and C32 paraffins to obtain jet fuel that meets the standard navy specifications. This step shall occur in the kilo lab section of the PDC using a small wiped film evaporator distillation system and shall be performed over a duration of 1 week.
Funded by the NAWCWD, this initial manufacturing contract by Albemarle kicked-off in February 2012. Upon completion, the resulting jet fuel will be tested by the US Naval Air Warfare Center – Aircraft Division (NAWCAD) as a continuing process for military certification through the Department of Defense. Once this testing is completed, larger production runs will be undertaken to continue with flight testing.
This initial production run is the first significant milestone under the Cooperative Research and Development Agreement (CRADA) signed between NAWCWD and Cobalt in 2010 to develop technology for the conversion of bio n-butanol into full performance jet and diesel fuels.
This CRADA was made possible by the US Federal Technology Transfer Act of 1986, which allows private organizations to access the expertise, capabilities and technologies of US Federal laboratories to improve the economic, environmental and social well-being of the United States.
The development of cost-effective and sustainable sources of fuel for military use is a high priority for the US Navy, which is aiming to cut the use of foreign-based fossil fuels in half by 2020. This summer, the Navy is planning on using the recent purchase of 450,000 gallons of biofuel for the Rim of the Pacific (RIMPAC) maritime exercise as part of the Great Green Fleet demonstration, a carrier strike group composed of nuclear ships, hybrid electric ships running biofuels and aircraft flying on biofuels.
Additionally, by 2016 the Great Green Fleet will be fully deployed using 50/50 blends of biofuels for ships and aircraft.
NAWCWD Alcohol-to-Jet Fuel Technology: A Linchpin Technology for a “Green” Jet and Diesel Fuel Solution ( NAWCWD presentation)
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 doi: 10.1021/ef800380b