Standard Test Method for Determination of Solvent Red 164 Dye Concentration in Diesel Fuels

Importancia y uso:

5.1 This test method was developed to provide for the enforcement of 26 CFR 48.4082-1(b), which mandates that all tax-exempt diesel fuels be dyed with an amount of Solvent Red 164 at a concentration that is spectrally equivalent to 3.9 lb/10³ bbl (11.1 mg/L) of Solvent Red 26. It is employed to verify that the correct amount of Solvent Red 164 is being added to tax-exempt product at terminals or refineries prior to sale, and to detect the presence of Solvent Red 164 in taxed product intended for on-road use.

5.1.1 Solvent Red 26 is the azo dye shown in Fig. 1. It is the standard against which the concentration of Solvent Red 164 is measured because it is available in a certified pure form. Solvent Red 164 is identical in structure to Solvent Red 26 except that it has hydrocarbon (alkyl) chains incorporated to increase its solubility in diesel and burner fuels. The exact composition of Solvent Red 164 will vary from manufacturer to manufacturer and lot to lot depending upon the extent of alkylation that occurs during production; however, its visible spectrum is virtually identical to the spectrum of Solvent Red 26. Solvent Red 164 is employed in the field (instead of Solvent Red 26) to dye tax-exempt diesel and burner fuels because of its higher solubility and relatively low cost.

FIG. 1 Structure of Solvent Red 26

Subcomité:

D02.05

Volúmen:

05.02

Número ICS:

75.160.20 (Liquid fuels)

Palabras clave:

dyed diesel fuel; second derivative spectroscopy; Solvent Red 26 Dye; Solvent Red 164 Dye; tax-exempt diesel fuels; visible spectroscopy;