Commercial processes involving

Most commercial processes involve copolymerization of ethylene with the acid comonomer followed by partial neutralization, using appropriate metal compounds. The copolymerization step is best carried out in a weU-stirred autoclave with continuous feeds of all ingredients and the free-radical initiator, under substantially constant environment conditions (22—24). Owing to the relatively high reactivity of the acid comonomer, it is desirable to provide rapid end-over-end mixing, and the comonomer content of the feed is much lower than that of the copolymer product. Temperatures of 150—280°C and pressures well in excess of 100 MPa (1000 atm) are maintained. Modifications on the basic process described above have been described (25,26). When specific properties such as increased stiffness are required, nonrandom copolymers may be preferred. An additional comonomer, however, may be introduced to decrease crystallinity (10,27). 

Reaction Injection Molding. RIM uses the anionic polymeri2ation of nylon-6 to carry out polymeri2ation in the mold. A commercial process involves the production of block copolymers of nylon-6 and a polyether by mixing molten caprolactam, catalyst, and polyether prepolymer, and reacting in a mold (27,28). 

Isopropyl Alcohol. Propylene may be easily hydrolyzed to isopropyl alcohol. Eady commercial processes involved the use of sulfuric acid in an indirect process (100). The disadvantage was the need to reconcentrate the sulfuric acid after hydrolysis. Direct catalytic hydration of propylene to 2-propanol followed commercialization of the sulfuric acid process and eliniinated the need for acid reconcentration, thus reducing corrosion problems, energy use, and air pollution by SO2 and organic sulfur compounds. Gas-phase hydration takes place over supported oxides of tungsten at 540 K and 25... 

A number of processes have been devised for purifying thionyl chloride. A recommended laboratory method involves distillation from quinoline and boiled linseed oil. Commercial processes involve adding various high boiling olefins such as styrene (qv) to react with the sulfur chlorides to form adducts that remain in the distillation residue when the thionyl chloride is redistilled (179). Alternatively, sulfur can be fed into the top of the distillation column to react with the sulfur dichloride (180). Commercial thionyl chloride has a purity of 98—99.6% minimum, having sulfur dioxide, sulfur chlorides, and sulfuryl chloride as possible impurities. These can be determined by gas chromatography (181). 

Plant cell suspensions offer the potential to produce valuable phytochemicals, traditionally extracted from the naturally grown whole plant, under controlled and reproducible conditions. To date, commercial processes involving these systems have been limited to just a handful of applications, including the much-cited shikonin [1] and ginseng [2,3]. 

Anodic processes can also be used for tetraethyllead electrosynthesis. Here solutions of organometallic compounds are used the overall reaction is replacement of the metal in these compounds by another metal, lead. One such process uses a melt of the compound NaAl(C2H5)4, from which radicals QHj are produced anodically. The process is highly efficient, but it is not easy to isolate the TEL produced from the melt. More convenient is a commercial process involving the anodic oxidation of the Grignard reagent C2H5MgCl ... 

All commercial processes involve either separation of nitrogen from air by cryogenic distillation or combustion of air with natural gas to remove oxygen. In the former process, air is liquefied and the liquid air is subjected to fractional distillation to separate its components. 

The most well-known electrodeposition process from the molten state is that of aluminum, which is deposited from a mixture of AI2O3 in AlF3-NaF at 965 °C. Other commercial processes involving molten salts exist and are exemplified by the deposition of tantalum and zirconium. Processes for Ti deposition from TiCl3 in KCl-LiCl entectics exist. All these escape almost completely97 from the H co-deposition problem of aqueous electrodeposition. 

Acrylonitrile. Another monomeric raw material that is produced from ethylene is acrylonitrile. The present commercial process involves the oxidation of ethylene to ethylene oxide which reacts with hydrogen cyanide and dehydrates to acrylonitrile. 

Manufacture and Processing. Most commercial processes involve copolymerizaiion of ethylene with the acid comonomer followed by partial neutralization, using appropriate metal compounds. 

Many commercial processes involving surface dyeing and printing (e.g., on film and containers) employ thermooxidation as a pretreatment step. Dyes adhere poorly to HDPE surfaces but their adhesion can be improved by thermooxidation of the surface layer by treatment with an open flame or 111 a strong electric field. 

Many transferases are involved in the biosynthesis of compounds of interest to the food, fine chemicals, and pharmaceutical industries. To date, however, there are no commercial processes involving the deliberate use of transferases. The often expensive cofactor requirement hampers their practical applications, although whole cell conversions might offer a solution to this problem. 

Table IV. Main commercial processes involving zeolites...

The second part of the book centers around a few catalytic applications each dealing with important commercial processes involving Ce02 in some stages. The use of ceria in auto-exhaust treatment and the role of sulfur in catalyst deactivation is specifically addressed in chapters 10 and 11 for spark ignited engines and chapter 12 for diesel engines. The relevance of ceria in total oxidation catalysis is the main... 

Because the reaction results in the addition of a hydrogen atom and the formyl group (CHO) to the double bond, it would more properly be called hydrofoimylation. However, the name Oxo has been generally accepted. The commercial process involves a second step in which aldehydes are reduced with hydrogen to primary alcohols. 

Hexamethylenediamine (HMDA) is a precursor for nylon 6/6. There are numerous routes to HMDA, but all of the commercial processes involve the synthesis of adiponitrile and the subsequent hydrogenation of adiponitrile to HMDA. The dominant process is the reaction of hydrogen cyanide with 1,3 butadiene to form adiponitrile followed by hydrogenation of adiponitrile to hexamethylene diamine. 

Fresh leaves, seed, and fruit peel Generally, GSE is professionally manufactured. The exact manufacturing process is a closely kept secret, and there is some (disputed) evidence that the commercial process involves more than a simple extraction procedure. It is unknown whether simple home extraction processes will produce the same efficacy as the commercial extract. The seeds, peel, and leaves may all be used. 

Poly(phenylene sulfide) (PPS) is the thio analogue of poly(phenylene oxide) (PPO) [57]. The first commercial grades were introduced by Phillips Petroleum in 1968 under the trade name Ryton. Other manufacturers also have introduced PPS (e.g., Tedur by Bayer). The commercial process involves the reaction of p-dichlorobenzene with sodium sulfide in a polar solvent. 

Continuous formation of flat sheets sheet glass) can be performed by drawing a ribbon directly from the melt. Different commercial techniques involve variations in the method used to control the initial point of ribbon formation, and in the direction of draw. All commercial processes involve initial vertical draws, but the ribbon is subsequently... 

Direct oxidation of the chloride is the usual commercial method of making phosphoryl chloride. Other commercial processes involve the reaction between phosgene and iron phosphate (4.317), but the simple reaction (4.318) has not yet been made commercially viable. 

Therefore this paper will firstly describe some of the important historical developments, then provide descriptions of the commercialized processes involving alkali jarosite/alunite precipitation, including discussion of the downstream impurity removal requirements necessary for efficient recovery of nickel and cobalt from solution. 

Alkylation of both isobutane and aromatics is of major industrial importance. Fifty years ago, liquid catalysts were used exclusively for commercial alkylation reactions. Liquid catalysts, namely, sulfuric acid and HF, are still used in commercial processes involving isobutane, which produce the highest quality gasoline. Numerous attempts have been made over the years to develop solid catalysts, but the catalysts always get quickly deactivated. Highly successful processes using solid catalysts have, however, been developed for the alkylation of aromatics. The solid catalysts have been employed for 2-7 years in at least some plants before being regenerated. 

Electrometallurgy. A major application of electrochemical principles and techniques occurs in the manufecture of such metals as aluminum and titanium. Plentiful aluminum-containing bauxite ores exist in lai e deposits in several countries, but it yms not until electrochemical techniques were developed in the United States and France at the end of the nineteenth century that the cost of manufecturing this light metal was sufficiently reduced to make it a commercially valuable commodity. This commercial process involved the electrolysis of alumina (aluminum oxide) dissolved in fused cryolite (sodium aluminum fluoride). During the century that followed this process s discovery, many different uses for this lightweight metal ensued, from airplanes to zeppehns. 

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