Chemical manufacture polymerization

Hazards Associated with Organic Chemical Manufacturing Polymerization Processes for Polyvinyl Chloride and Polyether Glycols, Mitre Corp., McLean, VA, Report No. MTR-79W00364-04, May 1979. 

Specialty sulfonic acid-based surfactants make up a rather large portion of surfactant production in the United States. Approximately 136,000 metric tons of specialty sulfonic acid-based surfactants were produced in 1992, which included alpha-olefin sulfonates, sulfobetaines, sulfosuccinates, and alkyl diphenyl ether disulfonates (64). These materials found use in the areas of household cleaning products, cosmetics (qv), toiletries, emulsion polymerization, and agricultural chemical manufacture. 

The control of chemical reactions (e.g., esterification, sulfonation, nitration, alkylation, polymerization, oxidation, reduction, halogenation) and associated hazards are an essential aspect of chemical manufacture in the CPI. The industries manufacture nearly all their products, such as inorganic, organic, agricultural, polymers, and pharmaceuticals, through the control of reactive chemicals. The reactions that occur are generally without incident. Barton and Nolan [1] examined exothermic runaway incidents and found that the principal causes were ... 

Batch microwave reactors, reactions in, 16 554-555 Batch mixers, 16 721 Batch mononitrotoluene process, 17 265 Batch multipurpose plants, for fine chemical manufacture, 11 427 Batch nitrobenzene process, 17 252 Batch-operated settling tanks, 22 59 Batch pilot plants, 19 458 Batch plants, certified, 20 703 Batch polymerization, of vinyl acetate, 25 608... 

Company E is a large chemical manufacturer with worldwide operations. CSB staff visited a mediumsized manufacturing site. Operations included storage and handling/processing of monomers, as well as extensive batch polymerization. The site uses standardized manufacturing methods and typically handles a specific set of chemicals. 

Propylene is manufactured by steam cracking of hydrocarbons as discussed under ethylene. The best feedstocks are propane, naphtha, or gas oil, depending on price and availability. About 50-75% of the propylene is consumed by the petroleum refining industry for alkylation and polymerization of propylene to oligomers that are added to gasoline. A smaller amount is made by steam cracking to give pure propylene for chemical manufacture. 

As we learned in Chapter 8, the official production of propylene is usually about half that of ethylene, only because a large part of the propylene is used by petroleum refineries internally to alkylate gasolines. This captive use is not reported. Of the propylene used for chemical manufacture, nearly 40% is polymerized to polypropylene, to be discussed in a later chapter. Of the remaining amount of propylene, seven chemicals from the top 50 are manufactured. These are listed in Table 10.1. Their industrial manufacturing methods are summarized in Fig. 10.1. Note that four of these chemicals, cumene, phenol, acetone, and bisphenol A, are also derived from a second basic organic chemical, benzene. 

Although the bulk of chemical manufacture is done on a continuous basis, there are sectors of the industry in which batch reactors are essential, notably for fermentations and polymerizations. Such plants may employ as many as 100 batch reactors. The basic processing steps include the charging of several streams, bringing up to reaction temperature, the reaction proper, maintenance of reaction temperature, discharge of the product, and preparation for the next batch. Moreover, the quality of the product depends on the accuracy of the timing and the closeness of the control. 

Much of the propylene is consumed by the petroleum refining industry for alkylation and polymerization to oligomers that are added to gasoline. A smaller amount is used for chemical manufacture. 

The manufacture of linear low-density polyethylene (LLDPE) by slurry polymerization in hexane (see Sections 6.2 and 6.8) is carried out by Hoechst, Mitsui, and a number of other chemical manufacturers in a series of continuous stirred tank reactors. The manufacture of butyraldehyde from CO, H2, and propylene using a soluble rhodium phosphine complex (see Sections 5.2 and 5.5) is also carried out in a continuous stirred tank reactor. 

A variety of chemical and biological reactions involving supercritical fluid technology are being explored and developed. They include polymerization reactions, biomass conversion, hydrogen production, applications of supercritical water oxidation, self-assembly applications, synthesis of specialty chemicals, manufacture of materials with tailored properties, and much more. These developments and new ones are expected to mature and be commercially deployed in years to come. 

This book presents and diseusses researeh in the study of polymers. Topies diseussed include extrusion heads used in manufacturing polymeric castings effects of polypropylene fibers on expansion properties of cement-based composite containing waste glass biodegradation of film polymer coating new polymer technologies with water and physical-chemical properties of natural polymers. 

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