DESC awarded a contract to Sustainable Oils for use of camelina as the feedstock to produce fuel, and Solazyme was awarded a contract for use of algae as the feedstock. UOP was awarded a contract for fuel made from tallow, or animal fat, provided by Cargill.

The UOP process technology for the production of high-quality renewable jet fuel was originally developed in 2007 under a contract from the US Defense Advanced Research Projects Agency (DARPA) to produce renewable JP-8 fuel for the US military. The process is based on UOP’s Ecofining process, which utilizes conventional refinery hydroprocessing technology and which is commercially available for the production of renewable diesel produced from biofeedstocks. (Earlier post.)

UOP’s Renewable Jet Process Chemistry. Source: Boeing. Click to enlarge.

Natural oils contain oxygen and have a high molecular weight. The process basically first removes the oxygen, resulting in diesel-range waxy paraffins. A second reaction cracks the diesel paraffins to smaller, highly branched molecules. While the Ecofining unit can produce up to 15 vol% of SPK jet fuel as a co-product with renewable diesel, the new process is designed to maximize the yield of SPK to 50-70 vol%.

This is achieved by optimizing the catalytic processes of deoxygenation, isomerization and selective cracking of the hydrocarbons present in natural oils and fats to yield a high quality, ultra-low sulfur jet fuel that meets Jet A-1 specifications, including freeze point of -47 °C (-52.6 °F) and flash point of 38 °C (100 °F). The renewable jet process deoxygenation and isomerization/selective cracking catalysts are supplied by UOP.

Co-products from this new process are diesel and naphtha range material. The process can be adjusted to produce a specific freeze point of the SPK or can alternately be operated to maximize diesel production.

A key difference between the new jet process and the Ecofining process is the need to reduce the natural oil carbon chain lengths to the required range for jet fuel. The renewable jet process uses a selective cracking step which reduces the natural oil C₁₆-C₁₈ carbon chain lengths to carbon chain lengths in the C₁₀ to C₁₄ range for jet fuel. UOP has shown the process using C₁₈ oils like soy, palm and canola oils; C₁₂ oils like coconut oil; inedible oils like jatropha and camelina and a variety of algal oils, to produce SPK fuel.

The technology was used to produce renewable jet fuel for demonstration flights conducted with Boeing, Air New Zealand, Continental Airlines and Japan Airlines earlier this year. In each flight, these biofuels met or exceeded performance specifications for petroleum-based jet fuel and displayed no adverse effects on any of the aircraft systems.

UOP, a recognized leader in refining process technologies, launched its Renewable Energy & Chemicals business in late 2006. In 2007, UOP commercialized the UOP/Eni Ecofining process to produce green diesel fuel from biological feedstocks, and in 2008 UOP formed the joint venture Envergent Technologies LLC with Ensyn Corp. to offer pyrolysis technology for the production of renewable heat, power and transportation fuels (earlier post). UOP is a wholly-owned subsidiary of Honeywell International, Inc. and is part of Honeywell’s Specialty Materials strategic business group.

Resources

• Status of Sustainable Biofuel Efforts for Aviation (Boeing, March 2009)