Antiknock

In addition to their antiknock properties, organic lead compounds possess bactericidal properties and motor fuels with lead are known to inhibit bacterial growth during storage in contact with water. With the disappearance of lead-based compounds, it is necessary to incorporate biocides from the cyclic imine family, (piperidine, pyrrolidine, hexamethyleneimine), alkylpropylene diamines or imidazolines (Figure 9.2). 

Concerning non-metallic compounds, the antiknocking properties of nitrogen compounds such that derivatives of aniline, indole and quinoline, and certain phenol derivatives have been mentioned. 

Whitcomb, R.M. (1975), Non-lead antiknock agents for motor fuels . Chemical Technology Review No. 49, Noyes Data Corporation, Park Ridge, NJ. 

Lead, like tin, forms only one hydride, plumbane. This hydride is very unstable, dissociating into lead and hydrogen with great rapidity. It has not been possible to analyse it rigorously or determine any of its physical properties, but it is probably PbH4. Although this hydride is unstable, some of its derivatives are stable thus, for example, tetraethyllead, Pb(C2Hj)4, is one of the most stable compounds with lead in a formal oxidation state of + 4. It is used as an antiknock in petrol. 

Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline antiknock compounds. Lead in gasoline, however, has been drastically reduced, due to environmental considerations. This will greatly affect future production of bromine. 

Antiknock agent Antiknock index Antileishmanial agent Antileukemic activity Antdon... 

In 1957, Ethyl Corp. announced anew antiknock compound, methylcyclopentadienyknanganese tricarbonyl [12108-13-3] (MMT). MMT is almost as effective as lead on a per gram of metal basis, but because manganese was more expensive than lead, MMT was not widely used until limits were placed on the lead content of gasoline. MMT was used in unleaded fuel between 1975 and 1978. After a large fleet test suggested that MMT could increase exhaust emissions because it interfered with catalysts and oxygen sensors, EPA banned its use in unleaded fuel in 1978. MMT is used in Canada in unleaded fuel. 

Ethyl Chloride. Most ethyl chloride [75-00-3] is produced by the hydrochlorination of ethylene (qv) using anhydrous HCl. Historically, the primary use of ethyl chloride was for the manufacture of tetraethyllead (TEL), a primary component of antiknock mixes in gasolines. Use has declined as a... 

The largest consumption of sodium worldwide, as of the mid-1990s, is the production of tetraethyUead and tetramethyUead antiknock compounds for gasoline. This production is outside of North America. Sodium is also used for the production of other organometaHic compounds such as methylcyclopentadienyknanganese tricarbonyl (MMT), another gasoline additive. 

Alkylate. Alkylation means the chemical combination of isobutane with any one or a combination of propylene, butylenes, and amylenes to produce a mixture of highly branched paraffins that have high antiknock properties with good stabiUty. These reactions are cataly2ed by strong acids such as sulfuric or hydrofluoric acid and have been studied extensively (98—103). In the United States mostly butylenes and propylene are used as the olefins. 

Includes paints and poHshes, antiknock and other compounds, soldering and/or welding, electrical and electronic products, mechanical products, magnetic tape, small packages, industrial diamonds, and drilling mud. 

Metal carbonyls have been used as antiknock compounds in unleaded gasoline (see Gasoline and other motor fuels). The Ethyl Corp. marketed methylcyclopentadienyknanganese tticarbonyl (MMT) however, as in the case of tetraethyllead (180), its use is prohibited because of environmental concerns. 

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). 

Structural, Al alloy Oxidation catalyst Fluxes, enamel frit Glass, ceramics Detergents Fire retardants Rubber catalyst Photographic Antiknock agents Medicinals Fertilizers... 

Cyanohydrins are used primarily as intermediates in the production of other chemicals. Manufacture of methyl methacrylate, used to make acrylic mol ding resins and clear sheet, eg, Plexiglas acrylic sheet, from acetone cyanohydrin is the most economically important cyanohydrin process (see Methacrylic polymers). Cyanohydrins are also used as solvents in appHcations including fiber-spinning and metals refining. Cyanohydrins and derivatives reportedly act as antiknock agents in fuel oil and motor fuels and serve as electrolytes in electrolytic capacitors. 

Ethyl Chloride. Previously a significant use for industrial ethanol was the synthesis of ethyl chloride [75-00-3] for use as an intermediate in producing tetraethyllead, an antiknock gasoline additive. Ethanol is converted to ethyl chloride by reaction with hydrochloric acid in the presence of aluminum or zinc chlorides. However, since about 1960, routes based on the direct addition of hydrochloric acid to ethylene or ethane have become more competitive (374,375). 

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

The most common toxic metals in industrial use are cadmium, chromium, lead, silver, and mercury less commonly used are arsenic, selenium (both metalloids), and barium. Cadmium, a metal commonly used in alloys and myriads of other industrial uses, is fairly mobile in the environment and is responsible for many maladies including renal failure and a degenerative bone disease called "ITA ITA" disease. Chromium, most often found in plating wastes, is also environmentally mobile and is most toxic in the Cr valence state. Lead has been historically used as a component of an antiknock compound in gasoline and, along with chromium (as lead chromate), in paint and pigments. 

Heavy-walled drums once used for lead antiknock chemicals have been used for water storage or as barbecue pits, with subsequent risk to the user from residual toxic material. Equipment from the industry cited has for many years been cleaned, cut up, and sent under supervision to steel mills for recycle to eliminate the possible misuse of scrapped containers. 

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. 

Antikatalysator, m. anticatalyst, antikatalytisch, a. anticatalytic. Antiklopf-eigenschaft, /. antiknock property. 

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