Silicon in Gasoline
A new standard for determining the silicon content in gasoline and other products has been approved by ASTM International Committee D02 on Petroleum Products and Lubricants. ASTM D7757, Test Method for Silicon in Gasoline and Related Products by Monochromatic Wavelength Dispersive X-Ray Fluorescence Spectrometry, was developed by Subcommittee D02.03 on Elemental Analysis.
ASTM D7757 covers the determination of total silicon by monochromatic, wavelength-dispersive X-ray fluorescence spectrometry in naphthas, gasoline, RFG, ethanol and ethanol fuel blends, and toluene at concentrations of 3 to 100 mg/kg.
Kishore Nadkarni, Ph.D., Millennium Analytics Inc., and chairman of D02.03, says that silicon contamination of gasoline, denatured ethanol and their blends has led to fouled vehicle components such as spark plugs, exhaust oxygen sensors and catalytic converters. Silicon fouling leads to costly parts replacement and repairs.
"Any level of silicon in fuel gasoline is unacceptable since combustion results in silica deposits on the oxygen sensor in the engine exhaust, which can lead to a breakdown in the closed loop electrical feedback to the engine electronic control unit," says Nadkarni. "The result is a complete loss of vehicle driveability."
According to Nadkarni, the test method described in ASTM D7757 is already being used successfully for determining silicon compounds in gasoline, gasoline-oxygenate blends, denaturants, hydrocarbon blend components and denatured fuel ethanol.
Nadkarni also notes that ASTM D7757 will fill industry needs as well as facilitating the continued development of new technology that will benefit consumers.
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ASTM Committee D02 Next Meeting: Dec. 2-6, 2012, Norfolk, Va.
Technical Contact: Kishore Nadkarni, Millennium Analytics Inc., East Brunswick, N.J., Phone: 732-613-8710
ASTM Staff: David Bradley, Phone: 610-832-9681