Pennsylvania Agriculture Agency Chooses Analyzers for Biodiesel Tests

The Pennsylvania Department of Agriculture (PDA) must ensure compliance with Pennsylvania's renewable fuel standard, which mandates increases in the percentage of biofuels available to consumers. Effective May 1, all diesel fuel sold at retail stations in the state must contain 2 percent biodiesel.

Testing the fuel at the 1,200 retail motor fuel locations throughout the state is one of PDA's responsibilities.

The agency chose the InfraCal Biodiesel BlendAnalyzer manufactured by Wilks Enterprise, Inc. to use for compliance monitoring because the analyzer could be used in the field and had the required accuracy of 0.2 percent. PDA recently purchased eight analyzers ─ one for each of seven regions to be shared by 33 field staff and one for its headquarters. While testing has not yet come into full swing, Mike Rader, the lead person on all renewable and alternative energy efforts for PDA, estimates that they will run approximately 2,000 samples annually for the on-road program. If pending legislation that includes a biodiesel mandate for both bio-heat and off-road fuel goes through, another billion gallons of biodiesel blended fuel will be added to the 1.6 billion gallons now in circulation for on-road diesel use. This would easily add another 2,000 biodiesel blend tests per year for PDA.

The approved methods for biodiesel measurement are ASTM D 7371 in the United States and EN 14078 in Europe. Both specify mid-infrared for the measurement of the biodiesel or FAME (fatty acid methyl ester) blend ratio. Infrared analysis works well for FAME because the biodiesel ester has characteristic infrared absorption due to the carbonyl band at 5.7 micrometers or 1745cm-1. As the concentration of biodiesel goes up, the infrared absorbance at that wavelength increases. The infrared absorbance can be directly calibrated to readout in percent biodiesel.

Since the InfraCal Biodiesel Blend Analyzer is 6 inches square, weights less than 5 pounds, and has no moving parts, it fits the requirements needed for traveling to retail stations to make on-site measurements, according to a Wilks Enterprise press release. The operation simply involves putting a sample on the exposed sample plate, pressing the “run” button and in less than a minute, the display reads the percent biodiesel in the fuel sample.

When the PDA finds a fuel that is out of compliance, a sample is sent to the headquarters for further testing. If that sample is verified as out-of-compliance, the department checks the required bill of lading tracking system that follows the fuel as it travels from the biodiesel producer to the blender, to the distributor, and finally to the retail location. With this paper trail, PDA can identify the entity responsible for the out of compliance fuel and a correction can be enacted.

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