Diesel Adulteration Detection Using Gaseous Vapor Emission

Donatus Uchechukwu Onyishi; O'tega Ejofodomi

Abstract

Diesel adulteration is the illegal or unauthorized introduction of foreign substances into pure diesel,causing the product to not conform to the requirements and specifications for use in the Oil and GasIndustry. Current methods to detect diesel adulteration require chemical laboratory experiments tomeasure parameters such as density, API gravity, viscosity, flash point, and evaporation point. Thesemethods require specialized, expensive equipment and cannot be utilized be quickly and readilyemployed at point of sale terminals (POS) prior to product purchase. Gaseous Vapor Emission (GVE)is a relatively new technique that analyzes the gaseous vapor emissions released by samples ofpetroleum products to detect the presence of adulterants, if any. The technique is portable, and can beused to detect adulteration at POS terminals such as fuel stations. GVE was performed on a 1 Lsample of pure diesel obtained from a Nigerian National Petroleum Corporation (NNPC) retailoutlet. Results showed that in an enclosed space of approximately 19,000 cm3, pure diesel emitted17.52–46.58 ppm of methane, 5.35–11.93 ppm of LPG, 35.51–84.6 ppm of butane, and 10.38–26.59ppm of toluene. The emission concentrations these four gases attained their peak within 10–20seconds of diesel exposure to open air. The timing and characteristics of these emissions serve as thechemical signature of pure diesel for GVE testing, and was successfully utilized to detect samples ofunadulterated diesel. The reported GVE chemical signature for pure petrol is different from thatobserved by pure diesel. Future work involves exploiting this difference to distinguish between pureand petrol-adulterated diesel at Point of Sale (POS) terminals. Future work also involves obtainingthe GVE chemical signature for kerosene for detection of kerosene-adulterated diesel at POSterminals.

Abstract

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