FAME is a product manufactured through the trans-esterification of vegetable oils and animal fats with methanol which is blended with diesel to produce biodiesel.
When FAME is added to conventional diesel to make ‘BX’ blends, the ‘X’ stands for the percentage of biodiesel added. For example; a B5 blend contains 5% biodiesel and 95% regular refinery diesel.
The Introduction of Biodiesel
In response to increasing concerns over global warming and carbon emissions many countries have introduced the use of biodiesel as an alternative fuel. In some cases this has become a mandatory requirement by governments. As a result the amount of biodiesel in the distribution system is set to increase over the next few years and there is a chance for cross-contamination between petroleum products.
FAME in Jet Fuel
Aviation fuel does not normally contain FAME, however wherever aviation fuel is transported (see Figure 1) there is risk of FAME contamination from mixing with previous cargos or poor pipeline/tank cleaning, whether at a terminal or onboard ship.
A number of incidents resulting in FAME contamination of aviation fuel have been reported over the years:
- Jet fuel storage tanks were quarantined at Birmingham International Airport after it was discovered that the samples in question contained FAME. The airport ceased refuelling and was closed for the weekend. The cause of contamination was the co-transport of biodiesel and jet fuel in the multiproduct pipelines.
- Two events at Belfast City airport.
- A high level of FAME was discovered in Corsica resulting in disruption to supplies.
- An event in the Azores occurred which lead to disruptions in the fuel supply.
How does FAME get into jet fuel?
FAME is a surfactant (surface active agent) which means that it adheres to metal surfaces. This is a problem as the fuel distribution network (pipelines, tankers and barges) are often shared. If jet fuel follows a cargo of biodiesel or BX diesel FAME can be dissolved into the jet fuel.
What are the concerns over FAME?
There are other issues relating to FAME and long term storage due to its relatively poor oxidative stability and if water is present, ideal conditions for microbial growth are created.
What’s occurred as a result?
In some cases, as a result of potential FAME contamination, shared distribution has been stopped to mitigate the risk. This has resulted in a significant increase in costs and protocols, such as EI 1530, which have been updated to advise the industry of best practices.
The UK Energy Institute (EI) formed a Joint Industry Programme (JIP) to look into how much FAME could be allowed in jet fuel without causing operational or service issues. The report demonstrated that 100 mg/kg of FAME was a reasonable limit for FAME contamination of aviation fuel. The industry is taking a cautious approach with the latest updates to ASTM D1655 and Defence Standard 91-91 approving 50 mg/kg, ASTM D1655 will allow an emergency level of 100 mg/kg with engine and airframe OEM’s approval.
FTIR Rapid Screening Method (FIJI)
In response to FAME contamination in jet fuel, SetaAnalytics began to develop a procedure and unique apparatus based on the use of Solid Phase Extraction (SPE) cartridge technology and IR spectroscopy. This development resulted in a new patented technique using flow analysis by FTIR – Fourier Transform Infrared Spectroscopy and the publication of IP 583 and ASTM D7797.
ASTM D7797, IP 583 ‘Determination of the Fatty Acid Methyl Esters content of Aviation Turbine Fuel using flow analysis by Fourier Transform Infrared Spectroscopy – Rapid Screening Method’
FIJI – Unique Attributes
- Short test duration: approximately 15 minutes
- All types of FAME can be detected in the ranges of C8 to C22, including and not limited to; coconut, mustard, palm, rapeseed, sunflower oil, soya and jatropha
- Minimal calibration required
- 1 test provides the total FAME content, irrespective of the type of FAME present
- Fully automatic
- Laboratory and field instrument
- Certified range 10-150 mg/kg
- No pre-sample preparation required
- Self cleaning therefore no cleaning solvents required
- Simple operation – pass/fail indication requires no operator interpretation (green/red colour light system)
- FIJI has the best precision of all test methods at the two key specification levels of 50 mg/kg and 100 mg/kg.
FIJI product page: http://www.johnmorris.com.au/FIJI-FAME-in-Jet-Instrument.aspx?pd=183550
FIJI brochure: Click Here
FIJI demonstration video: http://youtu.be/vntzb9_TlWg?list=PLebLrOOcc3OHKN3j3Vky1ELgbuyYWC8Ep
Target Market – who should test for FAME in jet fuel?
- Airport terminals
- Storage, handling
- Ships/barges – tank cleaning and flushing sea or jetty loading lines
- Military establishments
Competitive Advantages of FIJI
- FIJI requires no additional equipment or specialist training in order to operate.
- Operators using FIJI can either test samples at a laboratory or in the field.
- FIJI is diverse – it can test both AVTUR and diesel fuel 1
- Results are automatically calculated by FIJI and therefore no analytical chemistry is required.
- FIJI covers all FAME detection ranges (C8 to C22) without any additional equipment or testing.
- As no sample preparation, gases or additional equipment is required, FIJI is much more cost effective to run.
- Frequent calibration/verification is not required using FIJI but is with all three other analytical methods.
- In order to test diesel fuel, a software upgrade is required for compliance to ASTM D7963 Standard Test Method for Determination of Contamination Level of Fatty Acid Methyl Esters in Middle Distillate and Residual Fuels using Flow analysis by Fourier Transform Spectroscopy – Rapid Screening Method.
Method Precision Comparison Table
The table below provides a method comparison of precision at selected FAME concentrations with the 50 mg/kg level highlighted.
INDUSTRY COMPLIANCE: FUEL SPECIFICATION UPDATES FOR 2015
ASTM D1655 and Defence Standard 91-91, the specifications for Aviation Turbine Fuels, AVTUR, Jet A, and Jet A-1, have been updated to allow the new 50mg/kg FAME limit and now include IP 583 and ASTM D7797.
Changes to ASTM D1655
- Table 3 – Incidental Materials has been updated and the level of FAME permitted in JET fuel has been increased from 5 mg/kg to 50mg/kg.
- An emergency release of 100 mg/kg is permitted when authorized by the airframe and engine manufacturers.
- Table 3 includes the FIJI Rapid Screening methods, IP 593 / ASTM D7797, as accepted test methods for the new 50mg/kg FAME level.
- The levels may increase to 100 mg/kg after two years, once the industry has been able to evaluate the field performance of fuels with higher FAME levels.
Download ASTM D1655: www.astm.org/Standards/D1655.htm
Changes to Defence Standard 91-91 – Issue 7, Amendment 3
- Table 1 – Incidental Materials will include a maximum of 50 mg/kg with an emergency release of 100 mg/kg.
- Table 2 includes the FIJI Rapid Screening methods, IP 593 / ASTM D7797, as accepted test methods for the new 50mg/kg FAME level.
- From 2nd May 2015 FAME measurement will become a mandatory part of recertification which is conducted at the upstream supply terminals and prior to movement to airport.
- FAME tests are now mandated in DefStan 91-91.
Note: 70% of jet fuel around the world is specified to DefStan 91-91.
Download DefStan 91-91: www.dstan.mod.uk [Note Registration is required]
Contact our team at John Morris Scientific for Stanhope Seta instrumentation
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