Acid Hydrochloric Phosphoric

Hydrogen Chloride as By-Product from Chemical Processes. Over 90% of the hydrogen chloride produced in the United States is a by-product from various chemical processes. The cmde HCl generated in these processes is generally contaminated with impurities such as unreacted chlorine, organics, chlorinated organics, and entrained catalyst particles. A wide variety of techniques are employed to treat these HCl streams to obtain either anhydrous HCl or hydrochloric acid. Some of the processes in which HCl is produced as a by-product are the manufacture of chlorofluorohydrocarbons, manufacture of aUphatic and aromatic hydrocarbons, production of high surface area siUca (qv), and the manufacture of phosphoric acid [7664-38-2] and esters of phosphoric acid (see Phosphoric acid and phosphates). 

Ghloromethylation. The reactive intermediate, 1-chloromethylnaphthalene [86-52-2] has been produced by the reaction of naphthalene in glacial acetic acid and phosphoric acid with formaldehyde and hydrochloric acid. Heating of these ingredients at 80—85°C at 101.3 kPa (1 atm) with stirring for ca 6 h is required. The potential ha2ard of such chloromethylation reactions, which results from the possible production of small amounts of the powerhil carcinogen methyl chloromethyl ether [107-30-2J, has been reported (21). 

Acid Treatment. The treatment of petroleum products with acids has been in use for a considerable time in the petroleum industry. Various acids such as hydrofluoric acid, hydrochloric acid, nitric acid, and phosphoric acid have been used in addition to the most commonly used sulfuric acid, but in most instances there is Httie advantage in using any acid other than sulfuric. 

The typical acid catalysts used for novolak resins are sulfuric acid, sulfonic acid, oxaUc acid, or occasionally phosphoric acid. Hydrochloric acid, although once widely used, has been abandoned because of the possible formation of toxic chloromethyl ether by-products. The type of acid catalyst used and reaction conditions affect resin stmcture and properties. For example, oxaUc acid, used for resins chosen for electrical appHcations, decomposes into volatile by-products at elevated processing temperatures. OxaUc acid-cataly2ed novolaks contain small amounts (1—2% of the original formaldehyde) of ben2odioxanes formed by the cycli2ation and dehydration of the ben2yl alcohol hemiformal intermediates. 

Chemical Processing. Activated carbon consumption in a variety of chemical processing appHcations is about 8% of the total (74). The activated carbon removes impurities to achieve high quaHty. For example, organic contaminants are removed from solution in the production of alum, soda ash, and potassium hydroxide (82). Other apphcations include the manufacture of dyestuffs, glycols, amines, organic acids, urea, hydrochloric acid, and phosphoric acid (83). 

Alkyl tertiary alkyl ethers can be prepared by the addition of an alcohol or phenol to a tertiary olefin under acid catalysis (Reycler reaction) sulfuric acid, phosphoric acid, hydrochloric acid, and boron trifluoride have all been used as catalysts ... 

Phenyl isothiocyanate has been prepared from thiocarbanilide by the action of phosphorus pentoxide, hydrochloric acid, iodine, phosphoric acid, acetic anhydride, and nitrous acid. It has also been prepared from ammonium phenyl dithiocarbamate by the action of ethyl chlorocarbonate, copper sulfate lead carbonate, lead nitrate, ferrous sulfate,and zinc sulfate. ... 

The resins are hardened by acidic conditions. Phosphoric acid, or more commonly ammonium chloride, an acid donor, is employed. The ammonium chloride functions by reaction with formaldehyde to give hydrochloric acid. Hexamine is also formed during this reaction. 

The most commonly used chromate passivation process is the Cronak process developed by the New Jersey Zinc Co. in 1936, in which the parts are immersed for 5-10 s in a solution containing 182 g/1 sodium dichromate and 6ml/l sulphuric acid. A golden irridescent film is formed on the zinc or cadmium surface. Many variants (all fairly acidic) have been developed subsequently all are based on dichromate (or chromic acid) with one or more of the following sulphuric acid, hydrochloric acid (or sodium chloride), nitric acid (or nitrate), phosphoric acid, formic acid and acetic acid. A survey by Biestek shows that several of these variants are as good as the Cronak process, although none is superior. 

The decomposition of the carbonate may be effected with dilute hydrochloric acid, dilute perchloric acid, or phosphoric(V) acid. The last-named acid is perhaps the most convenient because of its comparative non-volatility and the fact that the reaction can be more easily controlled than with the other acids. If dilute hydrochloric acid is employed, a short, water-cooled condenser should be inserted between the decomposition flask and the absorption train (see below). 

The first reported method for the direct phosphonomethylation of amino acids used phosphorous acid and formaldehyde (7). Typically, aqueous solutions of the amino acid, phosphorous acid, and concentrated (coned) hydrochloric acid were heated to reflux with excess aqueous formaldehyde or paraformaldehyde. The reaction proceeded equally well with either primary or secondary amines. However, with primary amines such as glycine, the yield of glyphosate was usually quite low, even at reduced temperature, and 1 1 1 stoichiometry. The resulting glyphosate acid (GLYH3) reacted faster than glycine, so the bis-phosphonomethyl adduct 2 always predominated. With excess phosphorous acid and formaldehyde, good isolated yields of this 2 1 adduct 2 have been obtained (8). 

The acidic reagents vary widely In their ability to lower NDPA levels In trifluralin The concentration of the acid Is critical to produce the desired effect In some Instances, the acid promoted additional nitrosamine formation, e g 10% hydrochloric acid, 40% phosphoric acid, ascorbic acid, etc Hydrochloric acid and hydrogen chloride gas were the most efficient at destroying NDPA Impurity ... 

Write formulas for each of the following acids (a) hydrochloric acid, (b) phosphorous acid, and (c) hypochlorous acid. 

The solution is then transferred into the coupling vessel equipped with a mechanical stirrer and, possibly in the presence of a surfactant, precipitated with acetic acid, hydrochloric acid, or phosphoric acid. The coupling component may also be precipitated indirectly i.e., the appropriate mixture of acid and emulsifier is filled into the kettle first and the alkaline solution of the coupling component is then added gradually to the clear solution by gravity flow. The clarified solution of the diazonium compound is then introduced into or onto this coupling suspension. 

The condensation reaction with aniline may also be accomplished in two separate steps. It is possible to separate succinylosuccinic ester, followed by condensation in boiling ethanol in the presence of an acid (acetic acid, hydrochloric acid, phosphoric acid). 

Reducing Agents Hydrogen, lithium aluminum hydride, sodium borohy-dride, di-isobutyl aluminum hydride, iron metal Acids Sulfuric acid, hydrochloric acid, phosphoric acid, methanesulfonic acid, acetic acid, formic acid... 

The processes in the second class involve the use of concentrated acids, such as 65 to 75% sulfuric acid, 85% phosphoric acid, 45% hydrochloric acid and anhydrous hydrofluoric acid. The wood is actually dissolved in the acid and allowed to stand until the cellulose is converted into polysaccharides of low molecular weight. Then the solution is diluted with water and boiled to convert the product into simple sugars. Sulfuric acid has not been used in commercial adaptations of these processes, although it was shown in 1882 by Flechsig that cotton cellulose could be converted almost quantitatively into sugar by the acid. 

Elemental composition P 14.88%, Cl 85.12%. The compound may be hydrolyzed with water and the products phosphoric and hydrochloric acids are measured for phosphate and chloride ions by ion chromatography and colorimetric methods (see Phosphoric Acid, Hydrochloric Acid). 

Table 1 Catalysts used for the dehydration of polysaccharides Organic acids Oxalic acid, levulinic acid, maleic acid, p-toluenesulfonic acid Inorganic acids Phosphoric acid, sulfuric acid, hydrochloric acid, iodine, or hydroiodic acid generated in situ...

BsaeHons,—1. By the action of on excess of water it pro duces hydrochloric acid and phosphoric acid i—... 

Polyolefins are resistant to aqueous solutions of inorganic acids such as hydrochloric, phosphoric, and sulfuric acids. These polymers are also resistant to chromic and nitric acids but react with them as well as with dinitrogen tetroxide at elevated temperatures. Polymers with tertiary hydrogen atoms, such as PP, are more readily oxidized than those with only secondary hydrogen atoms, such as hope. 

The checkers found that crude chloromethylnaphthalene obtained from the preparation in Organic Syntheses could be used with good results. Naphthalene, paraformaldehyde, hydrochloric acid, and phosphoric acid are heated under reflux according to the procedure described. After the crude product is washed with water, 10% potassium carbonate, and water, it is dissolved directly in 500 ml. of glacial acetic acid, diluted with 500 ml. of water, and treated with hexamethylenetetramine by the procedure described above. The over-all yield of almost colorless 1-naphthaldehyde is 162 g., b.p. 162-164°/18 mm. Wq 1.6503 (52% yield based on naphthalene). 

Non-Oxidizing Mineral Acids Hydrochloric Acid Hydrofluoric Acid Phosphoric Acid... 

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