Marker dyes from cardanol and aniline derivatives

Abstract

Marker dyes for petroleum products were synthesized by coupling reaction of cardanol, which was obtained from partially purification of decarboxylated cashew nut shell liquid, with diazonium salts of aniline derivatives, whose structures possessing different substituents on the benzene ring. These synthetic marker dyes were added into gasoline and high-speed diesel at levels of 2 to 5 ppm, and their presence could be detected by extraction into an appropriate alkali aqueous solution, providing visual colors that could be quantitatively determined by UV/VIS spectrophotometry. The testing results using the ASTM test methods revealed that the physical properties of the dyed fuel oils were similar to those of the undyed fuel oils. Moreover, those synthetic marker dyes were found to be stable in fuel oils up to at least three months, suggesting that these marker dyes could be readily applied in the commercial fuel oils.