Antiknock additives

Fuels, Lubricants, and Transmission Fluids. Polyol esters of neopentanoic acid have been used as high vacuum pumping hquids that are stable in chemically aggressive environments (70). Esters such as 6- -ani1inophenoxy)hexy1 pivalate are used as antioxidants for synthetic ester lubricants (71). PivaUc anhydride [1538-75-6] has been claimed as an antiknock additive for gasoline (72). 

By similar methods, ethyleae dibromide [106-93-4] can also be obtained. This compound is used ia gasoliae as an antiknocking additive. 

Multidimensional chromatography has also been applied for the analysis of industrial chemicals and related samples. Industrial samples which have been analyzed by multidimensional chromatography include coal tar, antiknock additives in gasoline (3), light hydrocarbons (4, 5), trihaloalkanes and trihaloalkenes in industrial solvents (6-8), soot and particulate extracts, and various industrial chemicals that might be present in gasoline and oil samples. 

Unbumt gasoline and cracked hydrocarbons such as ethylene and propylene are also substantial constituents of exhaust. Gasoline contains additives such as benzene, toluene and branched hydrocarbons to achieve the necessary octane numbers. The direct emission of these volatile compounds, e.g. at gas stations, is a significant source of air pollution. Leaded fuels, containing antiknock additions such as tetra-ethyl-lead, have been abandoned because lead poisons both human beings and the three-way exhaust catalyst, especially for the removal of NO by rhodium. 

The best known example is the electrosynthesis of tetraethyllead (TEL) Pb(C2Hj)4, which has been in wide use as an antiknock additive of gasoline, and still is in a number of countries. This substance is readily produced by reaction of ethyl radicals with the lead electrode ... 

Colorless oily liquid with a musty or fruity odor. Commercial material may be dyed red, orange, or blue. This material is hazardous through inhalation, skin absorption (liquid), penetration through broken skin, and ingestion, and produces local skin/eye impacts. Used industrially as an antiknock additive for gasoline. 

Dicyclopentadienyliron finds limited application as a catalyst. It was used earlier as an antiknock additive for gasoline. The complex also is used to synthesize other metal jr-complexes and their derivatives. 

Manganese decacarbonyl is used as an antiknock additive to gasohne and as a catalyst. 

Lead Tetraethyl (Tetraethyl lead, Lead Tetraethide, Tetraethyl Plumbane). Pb(C2Hs)4, mw 323.45, colorless liq, fr p -136°, bp about 200°, also stated as 227.7° with decompn, d 1.653g/cc at 20° insol in w si sol in ale, sol in benz and eth. May be prepd by die action of Pb chloride on Zn ethyl or on a Grignard reag. Used extensively as an antiknock addition to gasoline, and has been proposed by Fr investigators as a flash reducer in proplnts (Ref 2)... 

In practice, short-chain alkanes and alkenes are normally used as feedstock for shape-selective catalytic formation of isooctanes at relatively low temperatures. Until the 1980s, lead alkyls (Section 18.1) were added to most automotive fuels to help suppress engine knock, but they have been phased out in North America because of the chronic toxicity of lead and lead compounds. The most commonly used nonlead antiknock additive is now methyl tert-butyl ether [MTBE CH30C(CH3)3], which is made by the reaction of methanol with 2-methylpropene, (CHs C—CH2 (see Section 7.4). The latter is obtained by catalytic cracking of petroleum fractions to give 1-butene, which is then shape-selectively isomerized on zeolitic catalysts. 

Production of Alcohols by Hydration ofAlkenes. Several alcohols (ethyl alcohol, isopropyl alcohol, sec-butyl alcohol, ferf-butyl alcohol) are manufactured commercially by the hydration of the corresponding olefins.2 45 46 Ethanol, an industrial solvent and a component of alcohol-gasoline blends, and isopropyl alcohol—a solvent and antiknock additive—are the most important compounds. Isopropyl alcohol is often considered the first modem synthetic petrochemical since it was produced on a large scale in the United States in the 1920s. 

Clear Octane—The octane number of a gasoline before the addition of antiknock additives. 

Ogilivie et al(Ref 4) found that bromopicrin, choloropicrin, Br other compds caused an increase in the knocking tendency in aviation gasoline. These compds counteracted the effect of antiknock additives also had some effect on the base stock fuel... 

Lead tetraethyl Pb(C2H6)4 Antiknock additive in motor fluels... 

Discuss the historical aspects of organometallic compound toxicity, including organoarsenicals used as pharmaceutical agents, gasoline antiknock additives, and compounds used in applications such as catalysis and chemical synthesis. 

Large quantities of tetramethyl lead (TML) were used back in the 1960s as an antiknock additive in high-octane gasoline before they were banned because of air pollution problems. TML was produced in a batch reactor that had the interesting feature of requiring the removal of a byproduct during the batch. The main reaction involves a solid sodium-lead alloy and liquid methyl chloride ... 

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