Halogenation industrial

Fishbein L. 1979. Potential halogenated industrial carcinogenic and mutagenic chemicals II. Halogenated saturated hydrocarbons. Sci Total Environ 11 163-195. 

Van-Den-Berg KJ, van Raaij JAGM, Bragt PC, et al. 1991. Interactions of halogenated industrial chemicals with transthyretin and effects on thryoid hormone levels in vivo. Arch Toxicol 65 15-19. 

Although alkenes typically react with chlorine and bromine by addition at room tern perature and below (Section 6 14) substitution becomes competitive at higher tempera tures especially when the concentration of the halogen is low When substitution does occur It IS highly selective for the allylic position This forms the basis of an industrial preparation of allyl chloride... 

Butadiene is an industrial chemical and is prepared by dehydrogena tion of butane Elimination reactions such as dehydration and dehydro halogenation are common routes to alkadienes... 

Air. Biofilters are an effective way of dealing with air from industrial processes that use halogenated solvents such chloromethane, dichioromethane, chloroethane, 1,2-dichloroethane and vinyl chloride, that support aerobic growth (26). Both compost-based dry systems and trickling filter wet systems are in use. Similar filters could be incorporated into pump-and-treat operations. 

Adipic acid undergoes the usual reactions of carboxyflc acids, including esterification, amidation, reduction, halogenation, salt formation, and dehydration. Because of its biflmctional nature, it also undergoes several industrially significant polymerization reactions. 

Another factor potentially affecting the market for halogenated fire retardants is the waste disposal of plastics (see Wastes, industrial). As landfiU availabihty declines or becomes less popular, two alternatives are incineration and recycling (qv). The nature of the combustion products from halogenated products requires carefiil constmction and maintenance of incinerators (qv) to avoid damage to the incinerator itself and a pubHc health problem from the exhaust. The ease of recycling used products also has a potential effect on fire retardants. 

Fluorine reacts with the halogens and antimony to produce several compounds of commercial importance antimony pentafluoride [7783-70-2J, bromine trifluoride [7787-71 chlorine trifluoride [7790-91 -2J, and iodine pentafluoride [7783-66-6J. Chlorine trifluoride is used in the processing of UF (see Uraniumand uranium compounds). Bromine trifluoride is used in chemical cutting by the oil well industry (see Petroleum). Antimony and iodine pentafluorides are used as selective fluorinating agents to produce fluorochemical intermediates (see Fluorine compounds, inorganic). 

Chemical Properties. A combination of excellent chemical and mechanical properties at elevated temperatures result in high performance service in the chemical processing industry. Teflon PEA resins have been exposed to a variety of organic and inorganic compounds commonly encountered in chemical service (26). They are not attacked by inorganic acids, bases, halogens, metal salt solutions, organic acids, and anhydrides. Aromatic and ahphatic hydrocarbons, alcohols, aldehydes, ketones, ethers, amines, esters, chlorinated compounds, and other polymer solvents have Httle effect. However, like other perfluorinated polymers,they react with alkah metals and elemental fluorine. 

Halogenation and Hydrohalogenation. Halogens add to the triple bond of acetylene. FeCl catalyzes the addition of CI2 to acetylene to form 1,1,2,2-tetrachloroethane which is an intermediate in the production of the industrial solvents 1,2-dichloroethylene, trichloroethylene, and perchloroethylene (see Chlorocarbons and chlorohydrocarbons). Acetylene can be chlorinated to 1,2-dichloroethylene directiy using FeCl as a catalyst... 

Table 6. Halogen-Containing Industrial Antimicrobial Agents...

Cables are available in a variety of constmctions and materials, in order to meet the requirements of industry specifications and the physical environment. For indoor usage, such as for Local Area Networks (LAN), the codes require that the cables should pass very strict fire and smoke release specifications. In these cases, highly dame retardant and low smoke materials are used, based on halogenated polymers such as duorinated ethylene—propylene polymers (like PTFE or FEP) or poly(vinyl chloride) (PVC). Eor outdoor usage, where fire retardancy is not an issue, polyethylene can be used at a lower cost. 

Halogenation of nitromethane is utilized to produce two economically important pesticides, chloropicrin [76-06-2J, a soil fumigant, and bronopol, a biocide useful for control of microbial growth in cosmetics and industrial appHcations. 

Beside being acidic, a significant industrial chemical property of phenol is the extremely high reactivity of its ring toward electrophilic substitution. If steric conditions permit, the substitution leads first to the formation of the 2- or 4-mono derivative, then to the 2,4- or 2,6-diderivative, and finally to the 2,4,6-triderivative. The halogenation of phenol produces mono-, di-, and tribal ophenols. 

Compounds of type (42) are widely used in the dye industry (see Azo dyes). The Mannich reaction also takes place at C, as does halogenation and nitration. The important analgesic aminoantipyrine [83-07-8] (43) on photolysis in methanol undergoes ring fission to yield (44) (27). 

Catalysts. In industrial practice the composition of catalysts are usuaUy very complex. Tellurium is used in catalysts as a promoter or stmctural component (84). The catalysts are used to promote such diverse reactions as oxidation, ammoxidation, hydrogenation, dehydrogenation, halogenation, dehalogenation, and phenol condensation (85—87). Tellurium is added as a passivation promoter to nickel, iron, and vanadium catalysts. A cerium teUurium molybdate catalyst has successfliUy been used in a commercial operation for the ammoxidation of propylene to acrylonitrile (88). 

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