Chlorine source

Several commercial grades are available fine crystals of 99 to 100% purity, large crystals, pressed lumps, rods, and granular material. Double-Decomposition Methods. Double-decomposition processes all iavolve the reaction of sodium chloride, the cheapest chlorine source, with an ammonium salt. The latter may be suppHed directiy, or generated in situ by the reaction of ammonia and a supplementary iagredient. Ammonium chloride and a sodium salt are formed. The sodium salt is typically less soluble and is separated at higher temperatures ammonium chloride is recovered from the filtrate by cooling. 

The recent (since 1993) tightness of the chlorine market, which was accompanied by rising chlorine prices, sparked interest in alternative sources of chlorine, ie, HCl and EDC, where these are available. Some plants no longer operate in a strictly balanced mode, but instead operate with more than half of thek EDC made from oxychlorination (owing to importation of HCl or EDC as a chlorine source, thus bypassing dkect chlorination). The ideal situation is one in which the plant can adapt to any feed combination, allowing operation at the optimum mix of feedstocks as determined by minimization of the sum of raw material and operating costs. 

Oxychl orin ation of ethylene has become the second important process for 1,2-dichloroethane. The process is usually incorporated into an integrated vinyl chloride plant in which hydrogen chloride, recovered from the dehydrochlorination or cracking of 1,2-dichloroethane to vinyl chloride, is recycled to an oxychl orin a tion unit. The hydrogen chloride by-product is used as the chlorine source in the chlorination of ethylene in the presence of oxygen and copper chloride catalyst ... 

On top of this, PVC is by no means the only chlorine source. Other raw materials and (particularly for blast furnaces close to the sea) even the air used in incineration processes may have significant contributions to the chlorine throughput too. 

Chlorine is used in a particular chemical process. A source model study indicates that for a particular accident scenario 1.0 kg of chlorine will be released instantaneously. The release will occur at ground level. A residential area is 500 m away from the chlorine source. Determine... 

Recently, Duirk et al. [34] showed evidence that iodinated X-ray contrast media (ICM), such as iopamidol, constitute an iodine source to form iodo-THM DBFs, e.g., dichloroiodomethane, and iodo-acid DBFs, e.g., iodoacetic acid, in chlorinated and chloraminated drinking waters. However, the complete reaction pathway is not fully understood yet, and it is under further investigation. Chloraminated and chlorinated source waters with iopamidol were genotoxic and cytotoxic in mammalian cells. This is in agreement with the previously reported high genotoxicity and cytotoxicity of the iodo-acids and iodo-THMs [20, 21]. 

Figure 6.4 U.S. production of sodium hydroxide and chlorine, (Source Lowenheim and Moran and Chemical and Engineering News)...

Pyrotechnic compositions containing a barium compound and a good chlorine source can generate barium monochloride, BaCl, in the flame and the emission of green light will be observed. BaCl - an unstable species at room temperature - is an excellent emitter in... 

For the formation of 5-chloropyrimidines, AT-chlorosuccinimide is normally the reagent of choice, but several other electrophilic chlorine sources including chlorine gas or sulfuryl chloride can be used <1994HC(52)1>. For example, the chlorination of 4-(trifluoromethyl)-2(l//)-pyrimidinone 59 with ferric chloride and sulfuryl chloride in acetic acid gave the 5-chloro derivative 60 in 80% yield <2004EJ03714>. 

Second, reaction 8.9 and other relevant reactions appear to occur preferentially on available solid surfaces, which are often ice crystals but may also be particles of sulfate hazes from volcanic eruptions or human activity. Third, volatile bromine compounds are even more effective (via Br atoms) than chlorine sources at destroying ozone methyl bromide is released into the atmosphere naturally by forest fires and the oceans, but anthropogenic sources include the use of organic bromides as soil fumigants (methyl bromide, ethylene dibromide) and bromofluorocarbons as fire extinguishers (halons such as CFsBr, CF2BrCl, and C2F4Br2). 

Photocatalytic oxidation over illuminated titanium dioxide has been demonstrated to be effective at removing low concentrations of a variety of hazardous aromatic contaminants from air at ambient temperatures. At low contaminant concentration levels and modest humidity levels, complete or nearly complete oxidation of aromatic contaminants can be obtained in photocatalytic systems. Although aromatic contaminants are less reactive than many other potential air pollutants, and apparent catalyst deactivation may occur in simations where recalcitrant reaction intermediates build up on the catalyst surface, several approaches have already been developed to counter these potential problems. The introduction of a chlorine source, either in the form of a reactive chloro-olefin cofeed or an HCl-pretreated catalyst, has been demonstrated to promote the photocatalytic oxidation of... 

A convenient synthesis of chlorohydrins is based on the use of Chlorine T (TosNCINa) as the positive chlorine source in water-acetone.147 It adds to a variety of alkenes to form Markovnikov and anti-Markovnikov products in a ratio of 4 1. 

Knapska, D., Schmid, U., Jebsen, C., Kulessa, G., Rudolph, J. and Penkett S.A. (1985) Vertical profiles of chlorinated source gases in the midlatitude statrosphere, in C.S. Zerefos and A. Ghazi (eds.), Atmospheric Ozone, Reidel, Dordrecht, pp. 117-121. 

Figure 9.3. Homologue profiles of PCDD/DFs in soils from agricultural and urban areas (control sites) in Asian developing countries in comparison to the profile of samples representing environmental sinks (urban soils). Vertical bars represent the percentage of each homologue to total PCDD/F concentrations. F and D refer to dibenzofurans and dibenzo-p-dioxins, respectively. Numbers Figures indicate the degree of chlorination (Source Minh et al., 2003).

With the MMAO-activated catalyst system Nd( OPr)3/MMAO/halide donor a unique dependence of molar mass on the ratio of ftci/ Nd was obtained. Molar mass steadily decreases with increasing nci/nN(j-ratios (between 0.5 to 2.0) regardless of the type of chlorine source (Et2AlCl, fBuCl and Me3SiCl) [231]. 

During the 1970-1980s, a mixture of ammonium fluoroborate and antimony oxide was offered on the market. This mixture was used in polypropylene with dechlorane (a chlorine source) to achieve V-0. In the absence of added halogen source, the mixture can also achieve V-0 and a LOI of 33% in PP at a loading of about 37.5%. It was claimed that the mixture can be easily dispersed, has excellent UV stability, and is non-blooming, nonvolatile, and odorless. However, its water absorption in high humidity areas was a deficiency of this additive. 

If it is desired to carry out a chlorination, the apparatus is modified by replacing the dropping funnel and trap with a simple Y inlet tube attached directly to the reactor. One side of the Y is attached to the purge gas and the other to the chlorine source. If there is any question about the purity of the chlorine, it can be passed through a sulfuric acid wash. The chlorine flow rate during the reaction is about 300 ml./min. with no purge-gas flow. At the end of the reaction, the chlorine is purged from the system, and the product is removed as before. 

The chlorine atom can now be introduced by direct chlorination of tbe enamine with N-chloro-succinimide. This electrophilic chlorine source reacts via the mechanism that enols follow when they react with halogens (Chapter 21). 

Delmelle P., Stix J., Bourque C. P. A., Baxter P. J., Garcia-Alvarez J., and Barquero J. (2001) Dry deposition and heavy acid loading in the vicinity of Masaya volcano, a major sulfur and chlorine source in Nicaragua. Environ. Sci. Technol. 35(7), 1289-1293. 

Polyolefin Foams. Antimony oxide/chlorowax combinations or other aliphatic chlorine sources are generally used to fire retard polyolefin foams. Because of the higher processing temperatures required (up to 280 C or 536°F), when using azo blowing agents, the antimony ox-ide/chlorine system is inadequate, and in these cases phosphorus-containing fire-retardant systems are preferred (38). 

The filter cake is then stirred with 125 parts of water, the resulting oily layer is separated from the calcium chloride solution, dried with sodium carbonate and then distilled. The resulting alcohol is free from chlorine. Source Montonna 1922... 

Availability of chlorine source chemical Capital cost of the chlorination system Operation and maintenance costs of the equipment Chemical costs Location of the facility Operator skills Safety considerations... 

Oxidation of nitrogenous compounds. Both ketoximes and secondary nitro-alkanes are oxidized to ketones. Aldoximes are converted to nitroalkanes, but nitriles are formed under different conditions. In the presence of a chlorine source (NaCl, HQ) ketoximes give a-chloronitroaUcanes and nitroalkenes give the a-chlorinated products. ... 

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