Sodium hydroxide caustic product

Chemical Reactivity - Reactivity with Water A slow, non-hazardous reaction occurs, forming propanolamine Reactivity with Common Materials No reactions Stability During Transport The product is stable if it is kept in contact with solid caustic soda (sodium hydroxide) Neutralizing Agents for Acids and Caustics Dilute with water and rinse with vinegar solution Polymerization This material will polymerize explosively when in contact with any acid Inhibitor of Potymerization Solid sodium hydroxide (caustic soda). 

In this cell, not all of the dissolved sodium chloride is electrolyzed. Consequently, the solution that seeps through the perforated cathode contains sodium hydroxide together with some unchanged sodium chloride. The solution is concentrated by evaporation, whereupon most of the less soluble sodium chloride crystallizes and the very soluble sodium hydroxide remains in solution. This concentrated solution of sodium hydroxide (caustic soda) may be sold as such, or the remainder of the water may be driven off by heating to form solid sodium hydroxide. If a purer product is desired, the solid is dissolved in alcohol, which does not dissolve the remaining traces of sodium chloride. Pure sodium hydroxide is then secured by filtration, followed by evaporation of the alcohol. 

Production of a corrosive product (aqueous sodium hydroxide). Caustic stress corrosion cracking risks arise at around 120°C on stainless steel (Phenix superheater and resuperheater material is an austenitic stainless steel). 

Chlorine and sodium hydroxide (caustic soda) are among the top ten chemicals produced in the world. They are involved in the manufacturing of a wide variety of products (e.g., pharmaceuticals, detergents, deodorants, disinfectants, herbicides, pesticides and plastics). In 2010, the world production of chlorine amounted to approximately 50 ktons/year. 

The worldwide production of sodium hydroxide (caustic soda) in 2005 was -54 million tons. More than 98% of the sodium hydroxide is made along with chlorine by the electrolysis of brine. The remainder is made by reacting soda ash with lime. ° Most sodium hydroxide is sold as a 50% solution. However, it is usually sold in the form of Na20, where 77.5 g of Na20 is the same as 100 g... 

Sodium compounds are among the most used within the chemical industry. Aimu-ally about 30 million tonnes of sodium hydroxide (caustic soda) NaOH are manufactured in the world. The bulk is produced by electrolysis of a common salt solution, with chlorine and hydrogen as important by-products. This process is described in Chapter 50 Halogens. 

Let us talk about such an example. Paper industry needs a chanical called sodium hydroxide (caustic soda) to clean the pulp. The most convenient way to produce sodium hydroxide of a good quality is to use electrolysis of a brine solution containing sodium chloride. That is, if you put electric current through the solution, you can get a sodium metal which can easily be converted to sodium hydroxide by reacting the metal with a steam. The other product of the electrolysis of the brine solution... 

Figure 12.142 Production process for sodium hydroxide (caustic soda)...

Sodium hydroxide (caustic soda) is highly soluble in water, and sodium hydroxide solutions are strong bases. The annual world production of sodium hydroxide is on the order of 60 million tons. It is universally used as a neutralisation agent in the chemical industry, paper making, etc. Soda lye contains in general 30 wt% of sodium hydroxide. 

The chlor-alkali process is an industrial process of using sodium chloride electrolysis to produce chlorine and sodium hydroxide (caustic soda). Besides the two main products, hydrogen is also produced through this process. 

Sodium Hydroxide. Before World War 1, nearly all sodium hydroxide [1310-93-2], NaOH, was produced by the reaction of soda ash and lime. The subsequent rapid development of electrolytic production processes, resulting from growing demand for chlorine, effectively shut down the old lime—soda plants except in Eastern Europe, the USSR, India, and China. Recent changes in chlorine consumption have reduced demand, putting pressure on the price and availabiHty of caustic soda (NaOH). Because this trend is expected to continue, there is renewed interest in the lime—soda production process. EMC operates a 50,000 t/yr caustic soda plant that uses this technology at Green River it came onstream in mid-1990. Other U.S. soda ash producers have aimounced plans to constmct similar plants (1,5). 

Electrolytic Preparation of Chlorine and Caustic Soda. The preparation of chlorine [7782-50-5] and caustic soda [1310-73-2] is an important use for mercury metal. Since 1989, chlor—alkali production has been responsible for the largest use for mercury in the United States. In this process, mercury is used as a flowing cathode in an electrolytic cell into which a sodium chloride [7647-14-5] solution (brine) is introduced. This brine is then subjected to an electric current, and the aqueous solution of sodium chloride flows between the anode and the mercury, releasing chlorine gas at the anode. The sodium ions form an amalgam with the mercury cathode. Water is added to the amalgam to remove the sodium [7440-23-5] forming hydrogen [1333-74-0] and sodium hydroxide and relatively pure mercury metal, which is recycled into the cell (see Alkali and chlorine products). 

In the manufacture of 2-naphthalenol, 2-naphthalenesulfonic acid must be converted to its sodium salt this can be done by adding sodium chloride to the acid, and by neutralizing with aqueous sodium hydroxide or neutralizing with the sodium sulfite by-product obtained in the caustic fusion of the sulfonate. The cmde sulfonation product, without isolation or purification of 2-naphthalenesulfonic acid, is used to make 1,6-, 2,6-, and 2,7-naphthalenedisulfonic acids and 1,3,6-naphthalenetrisulfonic acid by further sulfonation. By nitration, 5- and 8-nitro-2-naphthalenesulfonic acids, [89-69-1] and [117-41-9] respectively, are obtained, which are intermediates for Cleve s acid. All are dye intermediates. The cmde sulfonation product can be condensed with formaldehyde or alcohols or olefins to make valuable wetting, dispersing, and tanning agents. 

Acid-cataly2ed hydroxylation of naphthalene with 90% hydrogen peroxide gives either 1-naphthol or 2-naphthiol at a 98% yield, depending on the acidity of the system and the solvent used. In anhydrous hydrogen fluoride or 70% HF—30% pyridine solution at — 10 to + 20°C, 1-naphthol is the product formed in > 98% selectivity. In contrast, 2-naphthol is obtained in hydroxylation in super acid (HF—BF, HF—SbF, HF—TaF, FSO H—SbF ) solution at — 60 to — 78°C in > 98% selectivity (57). Of the three commercial methods of manufacture, the pressure hydrolysis of 1-naphthaleneamine with aqueous sulfuric acid at 180°C has been abandoned, at least in the United States. The caustic fusion of sodium 1-naphthalenesulfonate with 50 wt % aqueous sodium hydroxide at ca 290°C followed by the neutralization gives 1-naphthalenol in a ca 90% yield. 

Sodium hydroxide, potassium hydroxide, or other caustic compounds are blended to make these types of removers. Polymer-type thickeners are added to increase the viscosity that allows the remover to be appHed with a bmsh, trowel, or spray. Some of these products use a paper or fabric covering to allow the remover finish mixture to be peeled away. The most common appHcation for this group of removers is the removal of architectural finishes from the interior and exterior of buildings. The long dwell time allows for many layers of finish to be removed with one thick appHcation of remover. 

Alkali Treatment. Caustic washing is the treatment of materials, usually products from petroleum refining, with solutions of caustic soda. The process consists of mixing a water solution of lye (sodium hydroxide or caustic soda) with a petroleum fraction. The treatment is carried out as soon as possible after the petroleum fraction is distilled, since contact with air forms free sulfur, which is corrosive and difficult to remove. The lye reacts either with any hydrogen sulfide present to form sodium sulfide, which is soluble in water, or with mercaptans, foUowed by oxidation, to form the less nocuous disulfides. 

The cleavage products of several sulfonates are utilized on an industrial scale (Fig. 3). The fusion of aromatic sulfonates with sodium hydroxide [1310-73-2J and other caustic alkalies produces phenohc salts (see Alkylphenols Phenol). Chlorinated aromatics are produced by treatment of an aromatic sulfonate with hydrochloric acid and sodium chlorate [7775-09-9J. Nitriles (qv) (see Supplement) can be produced by reaction of a sulfonate with a cyanide salt. Arenesulfonates can be converted to amines with the use of ammonia. This transformation is also rather facile using mono- and dialkylamines. 

Soluble Sta.nna.tes, Many metal staimates of formula M Sn(OH) are known. The two main commercial products are the soluble sodium and potassium salts, which are usually obtained by recovery from the alkaline detinning process. They are also produced by the fusion of stannic oxide with sodium hydroxide or potassium carbonate, respectively, followed by leaching and by direct electrolysis of tin metal in the respective caustic solutions in cells using cation-exchange membranes (27). Another route is the recovery from plating sludges. 

The chemistry of side reactions and by-products may also offer opportunities for increasing the inherent safety of a process. For example, a process involving a caustic hydrolysis step uses ethylene dichloride (EDC 1,2-dichloroethane) as a solvent. Under the reaction conditions a side reaction between sodium hydroxide and EDC produces small but hazardous quantities of vinyl chloride ... 

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