Industrial uses

Although employed, at one time, primarily as a war gas, phosgene is now an important chemical intermediate for the synthesis of a large number of commercial materials. Worldwide, it is used mainly in the manufacture of isocyanates (for urethane polymers and organic intermediates), polycarbonates (for speciality polymers), and monomeric carbonates and chloroformates (largely for the synthesis of pharmaceuticals and pest control chemicals). The established large-scale, commercial applications of phosgene are summarized in Fig. 4.7. 

The largest scale uses are thus based on the reactions of phosgene (or its direct derivatives) with either alcohols or amines. 

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Benzene was first isolated by Faraday in 1825 from the liquid condensed by compressing oil gas. It is the lightest fraction obtained from the distillation of the coal-tar hydrocarbons, but most benzene is now manufactured from suitable petroleum fractions by dehydrogenation (54%) and dealkylation processes. Its principal industrial use is as a starting point for other chemicals, particularly ethylbenzene, cumene, cyclohexane, styrene (45%), phenol (20%), and Nylon (17%) precursors. U.S. production 1979 2-6 B gals. 

Very high temperature and pressure on graphite in the presence of a metal catalyst gives synthetic diamonds big enough for many industrial uses. 

Emulsions have many industrial uses they... 

Liquid phase chromatography can use a supercritical fluid as an eluent. The solvent evaporates on leaving the column and allows detection by FID. At present, there are few instances in the petroleum industry using the supercritical fluid technique. 

Applied to vacuum residue, its purpose is to reduce the viscosity of the feedstock to a maximum so as to minimize the addition of light diluents for production of fuel-oil for industrial uses. 

The objective of this book is to provide a comprehensive introduction to the upstream industry useful for industry professionals who wish to be better informed about the basic methods, concepts and technology used. It is also Intended for readers not directly working in oil and gas companies but who are providing related support services. 

The materials are carbon steel (Hereafter, it is said S45C) and industrial use Titaniume (Hereafter, it is said Ti). The... 

The rapid development of the computer technique and the decreasing prices in spite of the increasing of performance have spread the use of personal computers (PCs) not only for industrial use but also for private use. Also, in spite of increasing requirements mea.surement and test systems become more and more economical, including NDT-systems. 

However, the deposition of salts from temporarily hard water in boilers, and so on (for example the fur found in kettles) makes it desirable to soften such water for domestic and industrial use. Very... 

Plutonium has assumed the position of dominant importance among the trasuranium elements because of its successful use as an explosive ingredient in nuclear weapons and the place which it holds as a key material in the development of industrial use of nuclear power. One kilogram is equivalent to about 22 million kilowatt hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20,000 tons of chemical explosive. 

Alkylation of isoalkanes with alkenes is of particular significance. The industrially used alkylation of isobutane with isobutylene to iso-... 

The reaction of trivalent carbocations with carbon monoxide giving acyl cations is the key step in the well-known and industrially used Koch-Haaf reaction of preparing branched carboxylic acids from al-kenes or alcohols. For example, in this way, isobutylene or tert-hutyi alcohol is converted into pivalic acid. In contrast, based on the superacidic activation of electrophiles leading the superelectrophiles (see Chapter 12), we found it possible to formylate isoalkanes to aldehydes, which subsequently rearrange to their corresponding branched ketones. 

Sandstone. Sandstone wheels were once quarried extensively for farm and industrial use, and special grades of stone for precision honing, sharpening, and lapping are a small but important portion of today s abrasive industry. Production of honing and sharpening stones from deposits of dense, fine grain sandstone in Arkansas account for 76% of the value (about 2 million in 1987) and 88% of the total quantity of such stones in the United States (4). 

Chemical Properties and Industrial Uses. Chloroacetic acid has wide appHcations as an industrial chemical intermediate. Both the carboxyhc acid group and the cx-chlorine are very reactive. It readily forms esters and amides, and can undergo a variety of cx-chlorine substitutions. 

Major industrial uses for chloroacetic acid are in the manufacture of cellulose ethers (mainly carboxymethylceUulose, CMC), herbicides, and thioglycolic acid. Other industrial uses include manufacture of glycine, amphoteric surfactants, and cyanoacetic acid. 

Acrolein as Diene. An industrially useful reaction in which acrolein participates as the diene is that with methyl vinyl ether. The product, methoxydihydropyran, is an intermediate in the synthesis of glutaraldehyde [111 -30-8]. 

The most important industrial use of pentaerythritol is in a wide variety of paints, coatings, and varnishes, where the cross-linking capabiUty of the four hydroxy groups is critical. Alkyd resins (qv) are produced by reaction of pentaerythritol with organic acids such as phthaUc acid or maleic acid and natural oil species. 

Other types of RPC have been proposed but are not in industrial use as of this writing. These include a reciprocated wire-mesh packing (188), a reciprocating screen-plate (205), and the multistage vibrating disk column (MVE)C) developed in Japan (189,206,207). These types of RPC may be useful for gas—hquid contact as well as Hquid-Hquid contact. 

The principle of fluorescent whitening was described in 1929 (1), but the industrial use of FWAs began about 10 years later. Since that time FWAs have found increasing use in the most diverse fields (2—5). The toxicological properties of fluorescent whiteners have been summarized (6). Commercial products investigated thus fat have been found to be completely harmless. Mote than 2000 patents for FWAs exist, there ate several hundred commercial products, and approximately one hundred producers and distributors. 

Chemical Applications. The chemical processing industry uses large amounts of granular and fine powder PTFE. Soft packing appHcations are manufactured from dispersions, and hard packings are molded or machined from stocks and shapes made from granular resin. 

Formic acid was a product of modest industrial importance until the 1960s when it became available as a by-product of the production of acetic acid by hquid-phase oxidation of hydrocarbons. Since then, first-intent processes have appeared, and world capacity has climbed to around 330,000 t/yr, making this a medium-volume commodity chemical. Formic acid has a variety of industrial uses, including silage preservation, textile finishing, and as a chemical intermediate. 

Potential fusion appHcations other than electricity production have received some study. For example, radiation and high temperature heat from a fusion reactor could be used to produce hydrogen by the electrolysis or radiolysis of water, which could be employed in the synthesis of portable chemical fuels for transportation or industrial use. The transmutation of radioactive actinide wastes from fission reactors may also be feasible. This idea would utilize the neutrons from a fusion reactor to convert hazardous isotopes into more benign and easier-to-handle species. The practicaUty of these concepts requires further analysis. 

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