Chlorin acid generation

In two proposed alternative processes, the chlorine is replaced in the hypochlorination reaction by hypochlorous acid [7790-92-3] HOCl, or tert-huty hypochlorite. In the first, a concentrated (>10% by weight) aqueous solution of hypochlorous acid, substantially free of chloride, chlorate, and alkah metal ions, is contacted with propylene to produce propylene chlorohydrin (113). The likely mechanism of reaction is the same as that for chlorine, as chlorine is generated in situ through the equiUbrium of chlorine and hypochlorous acid (109). 

Chlorine gas is usually used, but electrolysis of alkaline salt solutions in which chlorine is generated in situ is also possible and may become more important in the future. The final pH of solutions to be sold or stored is always adjusted above 11 to maximize stabiUty. The salt is usually not removed. However, when the starting solution contains more than 20.5% sodium hydroxide some salt precipitates as it is formed. This precipitate is removed by filtration to make 12—15% NaOCl solutions with about one-half of the normal amount of salt. Small amounts of such solutions are sold for special purposes. Solutions with practically no salt can be made by reaction of high purity hypochlorous acid with metal hydroxides. 

Hypochlorous acid undergoes a variety of reactions with organic substances including addition, oxidation, C- and iV-chlorination, and ester formation. On an industrial scale, hypochlorous acid, generated m situ via chlorine hydrolysis, reacts with propylene forming primarily the a-propjlene chlorohydrin isomer. 

An integrated process for producing chlorine dioxide that can consume chlorine (46) involves the use of hydrochloric acid as the reductant. The spent chlorine dioxide generator Hquor is used as feed for chlorate production, and hydrogen gas from chlorate production is burned with chlorine to produce hydrochloric acid. The principal disadvantage in the integrated hydrochloric acid-based processes is that the chlorine dioxide gas contains Y2 mole of chlorine for each mole of chlorine dioxide produced. A partial purification is achieved by absorption in chilled water in which the solubiHty of chlorine is less than chlorine dioxide however, this product stiU contains 10—15% chlorine on the basis of total chlorine and chlorine dioxide. 

The process requires water vapor removal from the generator to be balanced with the water introduced with the chloric acid feed. Significantly greater chlorine dioxide generator capacity is achievable than using the older design generators. 

Mechanisms in Chlorine Dioxide Generation from Chlorite. The reactions between sodium chlorite and chloriue-based oxidizers and acids are complex and involve the formation of the proposed unsymmetrical intermediate, [CI2O2] (16,18,22,36,108,135—140). 

The chlorine atoms generated in this first step are quite reactive in the presence of oxalic acid they can act as chain carriers for reaction (1). The experiment was performed by adding to a solution of CP and H2C204 a very low concentration of Fe2i at a constant rate R. Since reaction (3) is very fast, the rate of generation of Cl is equal to R. The chain-carrying steps are presumed to be... 

This wastewater stream contains lead (Pb) salts and chlorinated hydrocarbons generated from corrosion of the anodes as well as asbestos particles generated as a result of degradation of the diaphragm with use. Wastewater is also generated from the scrubber where the chlorine is wet scrubbed and from the ion exchange resin used to purify the brine solution. These wash water often contains dilute hydrochloric acid with small amounts of dissolved calcium magnesium and aluminum chloride. Like in other cells, the scrubber water also contributes to the wastewater stream. 

PPG [Pittsburgh Plate Glass Company] A process for making calcium hypochlorite. Hypochlorous acid and chlorine monoxide, generated by reacting chlorine and carbon dioxide with sodium carbonate monohydrate, are passed into lime slury. Invented in 1938 by I. E. Muskatt and G. H. Cady at the Pittsburgh Plate Glass Company. 

The reactivity of acidified chlorite solutions is reduced for bleaching some textiles by adding compounds like polyamines, pyrophosphates, and hydrogen peroxide that suppress the formation of chlorine dioxide (57). Another method is to buffer the solution at pH 5—6 to reduce the rate of chlorine dioxide formation. Hydrolysis of anhydrides and esters or oxidation of alcohols can be used to slowly generate acids to promote chlorine dioxide formation (58). Aldehydes also promote chlorine dioxide generation from neutral chlorite solutions, but the effect is greater than simply lowering the pH as they... 

Disulfides are generally oxidized with cleavage of the S —S bond. Hypofluorous acid in acetonitrile solution oxidizes sulfur atoms in bis(trifluoromethyl) disulfide to the highest oxidation state and, in addition, inserts an oxygen bridge between the sulfur atoms (Table 19).304 A sulfonyl chloride 18 is similarly obtained by the reaction of a substituted diphenyl disulfide with hypochlorous acid generated from chlorine and aqueous acetic acid.305... 

Summary This procedure is a duplicate of the procedure for the preparation of Iodine whereby chlorine is generated. Chlorine gas is prepared by dripping hydrochloric acid onto a strong oxidizing salt. During the reaction, chlorine gas is steadily evolved. 

Another hypothesis for the generation of chlorine acids is related with the interaction of dissolved oxygen with water and CCI5 to produce phosgenium, which would then decompose to CO2 and CI2 at temperatures above 100°C [40]. 

The chemistry of chlorine discussed in this section includes hydrolysis and optimum pH range of chlorination, expression of chlorine disinfectant concentration, reaction mediated by sunlight, reactions with inorganics, reactions with ammonia, reactions with organic nitrogen, breakpoint reaction, reactions with phenols, formation of trihalomethanes, acid generation, and available chlorine. 

Acid generation. Whether or not acid will be produced depends upon the form of chlorine disinfectant used. Using chlorine gas wiU definitely produce hydrochloric acid. Sodium hypochlorite and calcium hypochlorite will not produce any acid on the contrary, it can result in the production of alkalinity. Superchlorination using HOCI will definitely produce acids. 

Here s a modification for your chlorine gas generator. Put hydrochloric acid in the bleach bottle, and some cyanide in the pan Instead of sani-flush. Slick, huth Instant San Quentin all over the place. Better hold your nose when you punch your hole In the bleach bottle, or do It remotely somehow. 

The normal lining construction consists of a membrane on the steel shell and one layer of acid brick in a resin mortar. The membrane materials used have been a silica filled latex rubber or, more recently, a silica filled urethane. Either of these membranes is installed by troweling it onto the steel shell. The mortars used have been polyester or vinyl ester based and are used in the back joints, bed joints, and side joints. That is, the brick are completely surrounded by the mortar, except, of course, for the face. The equipment in which this type of construction is used includes the chlorine dioxide storage tank, the chlorine dioxide generator spent acid tank, and the chlorine dioxide bleach tower. 

Leaching and electrolysis processes can be used for metal recovery from waste electrical and electronic equipment. Metals such as Ag, Au, Cu, Pb, Pd, Sn, are dissolved from shredded electronic scrap in an acidic aqueous chloride electrolyte by oxidizing them with aqueous dissolved chlorine species. In the electrochemical reactor, chlorine is generated at the anode for use as the oxidant in the leach reactor and the dissolved metals are deposited from the leach solution at the cathode. The very low concentrations of the precious metal ions require the use of porous electrodes with high specific surface areas and high mass transport rates to achieve economically adequate reactor productivities and space-time yields [72]. 

Hypochlorous acid in ether. The hypochlorous acid generated by passing chlorine into sodium bicarbonate solution can be extracted with ether and the solution dried quickly and the titer determined. The Ruschig process for a modified Curtius degradation of 3/3-acetoxy-A"-bisnorcholenic acid (1) to pregnenolone (7) involves... 

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