Chlorine in oxidation

In divided cells the reaction at the counterelectrode is seldom a problem in aqueous solvents, oxygen evolution at the anode is convenient if chloride is desired as the anion, it is advisable to add ethanol to the anodic compartment as it reacts with the evolved chlorine. In oxidations, hydrogen evolution is a convenient counterelectrode reaction it may also be used in nonaqueous solvents [68-73]. In methylene chloride it has been noted that chloride ion formed by reduction of methylene chloride at the counterelectrode could diffuse to the anode compartment and participate in the follow-up reactions [426] this can be avoided by adding a little acetic acid to the cathode compartment. 

Cadmium chloride as catalyst in conversion of dipotassium 1,8-naph-thalenedicarboxylate to 2,6-naph-thalenedicarboxylic acid, 72 Chlorination, nuclear, aluminum chloride as catalyst for, 9 of pyruvic acid by sulfuryl chloride, 54 Chlorine in oxidation of methyl disulfide to methanesulfinyl chloride, 62 3-Chloroacetophenone from aluminum chloride catalyzed chlorination of acetophenone, 10... 

Halogens form films on stainless alloys, but their efficiency is limited because of fhe high volatility of mefal chlorides. Chlorine in oxidizing flue... 

Ozone is playing an important role as a clean and powerful oxidant in water treatment, in the pulp and food industry and in the medical industry, because ozone, unlike chlorine, does not generate harmful residues such as haloform, etc. during the reactions and is six times as strong as chlorine in oxidizing power. Disinfection methods are divided into four categories high-temperature disinfection, UV disinfection, iodine disinfection, and chlorine disinfection. 

A disproportionation. Chlorine in oxidation number zero is simultaneously oxidized (to oxidation number +1 in CIO") and reduced (to oxidation number -1 in C1-). 

When magnesium oxide is chlorinated in the presence of powdered coke or coal (qv), anhydrous magnesium chloride is formed. In the production of magnesium metal, briquettes containing CaCl2, KCl, NaCl, MgO, and carbon are chlorinated at a temperature such that the electrolyte or cell melt collects at the bottom of the chlorinator, enabling the Hquid to be transferred directly to the electrolytic cells. 

The purple permanganate ion [14333-13-2], MnOu can be obtained from lower valent manganese compounds by a wide variety of reactions, eg, from manganese metal by anodic oxidation from Mn(II) solution by oxidants such as o2one, periodate, bismuthate, and persulfate (using Ag" as catalyst), lead peroxide in acid, or chlorine in base or from MnO by disproportionation, or chemical or electrochemical oxidation. 

Chlorination. In some instances, the extraction of a pure metal is more easily achieved from the chloride than from the oxide. Oxide ores and concentrates react at high temperature with chlorine gas to produce volatile chlorides of the metal. This reaction can be used for common nonferrous metals, but it is particularly useful for refractory metals like titanium (see Titanium and titanium alloys) and 2irconium (see Zirconium and zirconium compounds), and for reactive metals like aluminum. 

The chlorohydrin process involves reaction of propylene and chlorine in the presence of water to produce the two isomers of propylene chlorohydrin. This is followed by dehydrochlorination using caustic or lime to propylene oxide and salt. The Dow Chemical Company is the only practitioner of the chlorohydrin process in North America. However, several companies practice the chlorohydrin process at more than 20 locations in Germany, Italy, Bra2il, Japan, Eastern Europe, and Asia. 

The oxidation of trichloromethanesulfenyl chloride by nitric acid or oxidative chlorination in the presence of water yields trichi oromethanesulfonyl chloride [2547-61-7] CCI2SO2CI, which is a lacrimatory soHd (mp 140—142.5°C), which is surprisingly stable to hydrolysis and can be steam-distiUed. 

Manufacture. Methanesulfonic acid is made commercially by oxidation of methyl mercaptan by chlorine in aqueous hydrochloric acid to give methanesulfonyl chloride which is then hydrolyzed to MSA. 

Chloride Process. In the chloride process (Fig. 3), a high grade titanium oxide ore is chlorinated in a fluidized-bed reactor in the presence of coke at 925-1010°C ... 

Chlorine. Chlorine is a weU known disinfectant for water and wastewater treatment, however, it can react with organics to form toxic chlorinated compounds such as the tribalomethanes bromodichloromethane, dibromochloromethane, chloroform [67-66-3] and bromoform [75-25-2]. Chlorine dioxide [10049-04-4] may be used instead since it does not produce the troublesome chlorinated by-products as does chlorine. In addition, by-products formed by chlorine dioxide oxidation tend to be more readHy biodegradable than those of chlorine, however, chlorine dioxide is not suitable for waste streams containing cyanide. 

R.. Gall, in R. G. Rice and. A. Cotmvo, eds., Oc nej Chlorine Dioxide Oxidation Products of Organic Materials Ozone Press International, Cleveland, Ohio, 1978, pp. 356-382. 

The next step of the UOP method of CCR regeneration is oxidation and chlorination. In this step, the catalyst is oxidized in air at about 510°C. A sufficient amount of chloride is usually added as an organic chloride, such as trichloroethane, to restore the chloride content and acid function of the catalyst to that of the fresh catalyst. If the platinum crystaUites ate smaller than about 10 nm, sufficient chlorine is present in the gas to completely tedispetse agglomerated platinum on the catalyst, as a result of the Deacon equUibtium ... 

The performance of many metal-ion catalysts can be enhanced by doping with cesium compounds. This is a result both of the low ionization potential of cesium and its abiUty to stabilize high oxidation states of transition-metal oxo anions (50). Catalyst doping is one of the principal commercial uses of cesium. Cesium is a more powerflil oxidant than potassium, which it can replace. The amount of replacement is often a matter of economic benefit. Cesium-doped catalysts are used for the production of styrene monomer from ethyl benzene at metal oxide contacts or from toluene and methanol as Cs-exchanged zeofltes ethylene oxide ammonoxidation, acrolein (methacrolein) acryflc acid (methacrylic acid) methyl methacrylate monomer methanol phthahc anhydride anthraquinone various olefins chlorinations in low pressure ammonia synthesis and in the conversion of SO2 to SO in sulfuric acid production. 

If decontamination caimot be left to natural processes, chemical neutralizers or means of physical removal must be employed. In general, the neutralizers are of two types chlorine-based oxidants or strong bases. Some neutralizers have been especially developed for the decontamination of chemical agents. 

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