Gasoline, manufacture octane number

Gasoline, manufacture of, 99-100 octane number of, 100 Gatterman-Koch reaction. 596 Gauche conformation, 95 butane and, 95-96 steric strain in, 96... 

Irrespective of the fuel supply chain, alternative fuels have generally lower tailpipe emissions in terms of local pollutants (such as NO, CO, S02, VOC and particle emissions) than conventional gasoline and diesel engines for instance, natural gas completely eliminates particle emissions synfuels are manufactured with very low sulphur and aromatic contents alcohol-based fuels have high octane numbers, which... 

During World War II, isopropyl benzene, more commonly and commercially known as cumene, was manufactured in large volumes for use in aviation gasoline. The combination of a benzene ring and an iso-paraffin structure made for a very high octane number at a relatively cheap cost. After the war, the primary interest in cumene was to manufacture cumene hydroperoxide. This compound was used in small amounts as a catalyst in an early process of polymerizing butadiene with styrene to make synthetic rubber. Only by accident did someone discover that mild treating of cumene hydroperoxide with phosphoric acid resulted in the formation of... 

World-Wide there is approximately 1000 tons of fluid cracking catalyst manufactured each day. Of this, about 35% contains some form of aluminum deficient zeolite Y, one whose SiOz/AlaOa ratio exceeds 5.5 1, and whose performance is generally characterized by enhanced olefin formation and higher gasoline research and motor octane number. The aluminum deficient... 

Cumene, discussed under C-3 chemistry, is the second-largest-volume chemical product made from benzene. About 25 percent of manufactured benzene is alkylated with propylene to form cumene. Although its high octane number makes it desirable in gasoline, most cumene is oxidized to the... 

After the addition of tetraethyllead to gasoline was prohibited, the oil companies were forced to make unleaded gasolines. In order to prevent engine knocking, the car manufacturers lowered the compression ratio of the engine, and oil companies changed the hydrocarbon composition of gasolines to incorporate more branched alkanes and aromatics to increase the octane number. Benzene and toluene were some additives, as well as ethanol in some cases. 

Isopentane is available in large amounts in Cj cuts from catalytic craddnj (see Section 2J.1X and can be produced by n-pentane isomerization. However, since it is widely sought after for the manufacture of gasolines due to its high octane number, this raw material is difficult to secure and costly for petrochemicals. 

The liquid products tend to be unsaturated and, because sulfur compounds are relatively more concentrated in heavy portions of crude oil, also tend to be rather high in sulfur content. The octane number of the gasoline depends upon the character of the feed, and typically ranges from 60-65 for paraffinic stocks to as high as 80 for highly naphthenic stocks. The coke can be used as fuel but in many cases is of a high quality suitable for use in the manufacture of carbon electrodes for the aluminum or other electrometallurgical industries. 

The transformation of light alkanes (C2-C4) over H-ZSM-5 and Ga or Zn modified H-ZSM-5 catalysts to aromatic hydrocarbons has been studied intensively in recent years, since it would expand the raw material base for the manufacture of aromatics [1, 2]. The aromatics produced can be used as feed-stock for plastics, as chemical source for many chemical processes, as additives for increasing the octane number in gasoline, etc. 

The hydrocarbon yields shown represent those expected averaged over the useful life of the ZSM-5 catalyst. Finished gasoline contains C4 s for vapor pressure control. For an 82.7 kPa (12 psi) RVP (Reid Vapor Pressure) finished gasoline, the yield is 86 wt% of hydrocarbons and the clear Research octane number is 93. Additional gasoline could be made by alkylating the propene and butenes produced with isobutane. As the amount of alkylate would be low, its manufacture would most likely be considered only for very large plants. 

FCC catalyst manufacturers are facing the challenge of developing materials that convert these more refractory feedstocks, while yielding cracked gasoline of improved octane numbers. Two concepts are being used in the design of an octane analyst ... 

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