Gasoline continued

Use of bromine-containing additives (ethylene dibromide) in leaded gasoline results in the release of bromomethane in exhaust fumes (about 70-220 pg/m of exhaust) (Harsch and Rasmussen 1977), and this may have been significant source of bromomethane release in the past. Combustion of unleaded gasoline releases much less bromomethane (about 4-5 pg/m ), so current emissions from this source are presumably much lower than previously, and are likely to decrease further as leaded gasoline continues to be phased out. 

Beginning in the 1920s, the compound tetraethyl lead was added to gasoline to improve performance. Unfortunately, the lead showed up in motor vehicle exhaust, where its inhalation posed a serious health hazard. In response to this problem, the Clean Air Act mandated a reduction in lead emissions. It was also discovered that lead in motor vehicle exhaust tended to coat the surface of the catalyst in the catalytic converter, rendering the catalyst ineffective. To remedy both problems, unleaded gasoline was introduced in 1974. Leaded gasoline continued... 

Fluid coking Vacuum residue Petrocoke, gas oil, gasoline. Continuous treatment in... 

The continuous cleaning of the admission system by an additive contained in the gasoline will help maintain the setting at its optimum value and will prevent the engine operation from drifting from its original settings. 

At the end of the 1960 s, oil refining underwent significant transformation linked to the continuous increase in the need for light products (gasoline-diesel oil) at the expense of heavy products (fuel-oils) as shown in Table 10.1. 

Direct fuel appHcations of methanol have not grown as anticipated (see Alcohol fuels). It is used in small quantities in California and other locations, primarily for fleet vehicle operation. Large-scale use of methanol as a direct fuel is not anticipated until after the year 2000. Methanol continues to be utilised in the production of gasoline by the Mobil methanol-to-gasoline (MTG) process in New Zealand. A variant of this process has also been proposed to produce olefins from methanol. 

Future technology developments in paraffin alkylation will be greatly influenced by environmental considerations. The demand for alkylate product will continue to increase because alkylate is one of the most desirable components in modern low emission gasoline formulations. Increased attention will be focused on improving process safety, reducing waste disposal requirements, and limiting the environmental consequences of any process emissions. 

Toluene demand in 1996 increased because of the new Amoco and Mobil (Chalmette) disproportionation plants as well as other capacity changes at Coastal (Eagle Point), Phillips (Sweeney), Gulf Chemicals (Arochem plant, Puerto Rico), Koch, and Texaco (Huntsman, Port Arthur). Dewitt (71) forecasts continued increase for this appHcation at the rate of about 14% between 1995 and the year 2000. These will have a significant effect on toluene price and availabiUty in the later 1990s. On the other hand, toluene demand for gasoline blending is expected to decline by about 283 million Hters by 1997-1998. 

Until 1960, coal was the source material for almost all benzene produced in Europe. Petroleum benzene was first produced in Europe by the United Kingdom in 1952, by Erance in 1958, by the Eederal Republic of Germany in 1961, and by Italy in 1962. Coal has continued to decline as a benzene source in Europe, and this is evident with the closure of coke ovens in Germany (73). Most of the benzene produced in Europe is now derived from petroleum or pyrolysis gasoline. In Europe, pyrolysis gasoline is a popular source of benzene because European steam crackers mn on heavier feedstocks than those in the United States (73). 

All of the benzoic acid producers in the United States employ the Hquid-phase toluene air oxidation process. As toluene becomes more important in the gasoline pool as an octane booster, the benzoic acid producers have to compete with gasoline marketers for the available toluene. If the attractiveness of toluene as an octane booster continues, the cost of producing benzoic acid will most likely increase. 

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