Octane number, of gasoline

Table 1 shows the major gasoline additives that were introduced from the 1920s through the 1980s. The increase in octane number of gasoline with use of these additives is shown. 

Another important use of RMs is the maintenance of conventional scales. The octane number of gasoline is an example of such a scale. The scale is defined through chemicals. This definition can be realized through RMs. Another example is the pH scale, which is defined by buffers with pH = 4, pH = 7, and pH = 10. These buffers are defined as mixtures of salts, dissolved in water. These define the pH scale can be used by laboratories for the purpose of calibrating their pH meters. 

Tenex-Plus A process for increasing the octane number of gasoline by a combination of hydrogenation and isomerization. See also Ben-Sat. 

The application of alcohol and gasoline-alcohol mixtures in the gasoline (Otto) engines began in the first half of the twentieth century. It is possible to find information about various studies on the change in octane numbers of gasoline-alcohol... 

Chica, A. and Corma, A. (1999) Hydroisomerization of pentane, hexane, and heptanes for improving the octane number of gasoline. J. Catal, 187, 167-176. 

R. Meusinger and R. Moros, Determination of octane numbers of gasoline compounds from their chemical structure by C NMR spectroscopy and neural networks. Fuel, 80, 613-621 (2001). 

For all values of m > 1, the function Q is convex and the mixture property is synergistic and for all values of 1 > m > 0, the function Q is concave and the mixture property is antagonistic, with the geometric mean as a special case where m = 1/2. For instance, the octane number of gasoline often follows the rule... 

The efficacy of an additive, such as tetraethyl lead on the octane number of gasoline, shows a concave curve so that the first cubic centimeter of additive would achieve much more than the second cubic centimeter, and the third cubic centimere would do even less. This can also be described by the term diminished return, which is described by d f/dx < 0, which is the characteristic of a function with a diminishing value of df/dx with increase in x. 

Problems related to engine knock can be readily diagnosed by measuring the octane number of gasoline. However, it is also possible to look at the distillation profile of gasoline and anticipate problems linked to engine knock. 

Dehydrogenation (Reforming)17-20—to increase octane number of gasoline, to produce alkenes from alkanes [Eq. (1.2)], as well as aromatics, such as benzene, toluene, and xylenes [Eq. (1.3)] ... 

Two studies in 1985 and 1992 focused on the use of superacids in isomerization.20,21 An important advantage of these catalysts is that they may be used at lower temperature because of their greatly increased ability to bring about carbo-cationic process. For example, aluminum chloride, still one of the important isomerization catalysts in industry, can be used at about 80-100°C. In comparison, superacids are active in alkane isomerization at room temperature or below. In addition to avoid side reactions under such conditions, lower reaction temperatures favor thermodynamic equilibria with higher proportion of branched isomers, which is fundamental in increasing the octane number of gasoline. 

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