Grading Gasoline

Dyes. Dyes are added to gasoline to impart color for a number of reasons. Originally, these compounds were used to identify leaded gasoline so that it would not be used for other inappropriate purposes, such as solvents. Dyes are used to identify different gasoline grades so that pipeline companies can separate tenders, and so that service stations can easily check that the correct grade was placed in the underground tanks (aq). Dyes are usually based on a2o chemistry and are added in concentrations below 10 ppm (see Azo dyes). 

The process can be modified to give predominandy or solely /-butyl alcohol. Thus, /-butyl hydroperoxide (and /-butyl alcohol) produced by oxidation of isobutane in the first step of the process can be decomposed under controlled, catalytic conditions to give gasoline grade /-butyl alcohol (GTBA) in high selectivity (19—22). 

With reference to the mechanism of cracking dodecane assess the relative environmental merits of the thermal and catalytic cracking processes to give gasoline grade products. 

Dyes Used to identify gasoline grades and types... 

TABLE 3-9. Selected Typical Properties of Aviation Gasoline Grades from ASTM D-910 Standard Specification for Aviation Gasoline... 

With the exception of gasoline grade /-butyl alcohol (GTBA), the butanols are generally marketed in bulk in the pure isomeric form. ASTM specifications (29) for -, iso- and jag butyl alcohol are given in Table 3. Butanol specification purity is routinely obtained by gas chromatography (30). 

A project at Amoco was undertaken to verify his NIR results and turn the instrument and measurement into something that could be used on-line. At first, there was total failure at duplicating his results with the precision that was needed to be useful. Then, the samples were split by gasoline grade and the results improved dramatically. When the sample sets were split by both grade and refinery it became clear that a very useful correlation between all three octane numbers and the NIR spectra could be constructed for specific grades and refineries. 

Meyer et cd. described the development of a multi-fuel processor by International Fuel Cells, LLC [627]. Methanol and gasohne (quality California reformulated gasoline grade II) were the major fuel alternatives. The technology chosen consisted of feed desulfurisation, autothermal reforming and catalytic carbon monoxide removal by two water-gas shift stages and two preferential oxidation reactors. The system had a power equivalent of 50 kW. However, performance data were only provided with respect to the autothermal reformer Desulfurisation proved to increase the reformer conversion up to 98%. No residual heavy hydrocarbons then remained in the product. The hot spot of the autothermal reformer approached 1000 °C. 

---