Chemical industry Industrial examples

Safety Management through Learning from Experience in the Chemical Industry Example of a New Incident Analysis Methodology, B. Wilpert, H. J. Uth, R. Miller, and E. Ninov... 

The sixth group of readers includes personnel managers not trained as scientists but employed by the phEumaceutical or other research-based chemical industries. Examples are the agricultural, food, perfumery, animal... 

Guideword Standard interpretations for chemical industry Example interpretation for PES... 

Not so for synthesis in the chemical industry where a compound must be prepared not only on a large scale but at low cost There is a pronounced bias toward reactants and reagents that are both abundant and inexpensive The oxidizing agent of choice for example in the chemical industry is O2 and extensive research has been devoted to develop mg catalysts for preparing various compounds by air oxidation of readily available starting materials To illustrate air and ethylene are the reactants for the industrial preparation of both acetaldehyde and ethylene oxide Which of the two products is ob tamed depends on the catalyst employed... 

The term feedstock in this article refers not only to coal, but also to products and coproducts of coal conversion processes used to meet the raw material needs of the chemical industry. This definition distinguishes between use of coal-derived products for fuels and for chemicals, but this distinction is somewhat arbitrary because the products involved in fuel and chemical appHcations are often identical or related by simple transformations. For example, methanol has been widely promoted and used as a component of motor fuel, but it is also used heavily in the chemical industry. Frequendy, some or all of the chemical products of a coal conversion process are not isolated but used as process fuel. This practice is common in the many coke plants that are now burning coal tar and naphtha in the ovens. 

In 1973 the Semiconductor Equipment and Materials Institute (SEMI) held its first standards meeting. SEMI standards are voluntary consensus specifications developed by the producers, users, and general interest groups in the semiconductor (qv) industry. Examples of electronic chemicals are glacial acetic acid [64-19-7] acetone [67-64-17, ammonium fluoride [12125-01 -8] and ammonium hydroxide [1336-21 -6] (see Ammonium compounds), dichloromethane [75-09-2] (see Cm.OROCARBONSANDcm.OROHYDROCARBONs), hydrofluoric acid [7664-39-3] (see Eluorine compounds, inorganic), 30% hydrogen peroxide (qv) [7722-84-1] methanol (qv) [67-56-1] nitric acid (qv) [7697-37-2] 2-propanoI [67-63-0] (see Propyl alcohols), sulfuric acid [7664-93-9] tetrachloroethane [127-18-4] toluene (qv) [108-88-3] and xylenes (qv) (see also Electronic materials). 

The dominant role of petroleum in the chemical industry worldwide is reflected in the landscapes of, for example, the Ruhr Valley in Germany and the U.S. Texas/Louisiana Gulf Coast, where petrochemical plants coimected by extensive and complex pipeline systems dot the countryside. Any movement to a different feedstock would require replacement not only of the chemical plants themselves, but of the expensive infrastmcture which has been built over the last half of the twentieth century. Moreover, because petroleum is a Hquid which can easily be pumped, change to any of the soHd potential feedstocks (like coal and biomass) would require drastic changes in feedstock handling systems. 

Most commercial processes produce polypropylene by a Hquid-phase slurry process. Hexane or heptane are the most commonly used diluents. However, there are a few examples in which Hquid propylene is used as the diluent. The leading companies involved in propylene processes are Amoco Chemicals (Standard OH, Indiana), El Paso (formerly Dart Industries), Exxon Chemical, Hercules, Hoechst, ICl, Mitsubishi Chemical Industries, Mitsubishi Petrochemical, Mitsui Petrochemical, Mitsui Toatsu, Montedison, Phillips Petroleum, SheU, Solvay, and Sumimoto Chemical. Eastman Kodak has developed and commercialized a Hquid-phase solution process. BASE has developed and commercialized a gas-phase process, and Amoco has developed a vapor-phase polymerization process that has been in commercial operation since early 1980. 

Promoters. Many industrial catalysts contain promoters, commonly chemical promoters. A chemical promoter is used in a small amount and influences the surface chemistry. Alkali metals are often used as chemical promoters, for example, in ammonia synthesis catalysts, ethylene oxide catalysts, and Fischer-Tropsch catalysts (55). They may be used in as Httie as parts per million quantities. The mechanisms of their action are usually not well understood. In contrast, seldom-used textural promoters, also called stmctural promoters, are used in massive amounts and affect the physical properties of the catalyst. These are used in ammonia synthesis catalysts. 

Feedstocks. A separate breakdown between fuels and feedstocks (qv) for the chemical industry (2) shows that the quantity of hydrocarbons (qv) used direcdy for feedstock is about as great as that used for fuel (see Fuels, synthetic Gasoline and other motor fuels). Much of this feedstock is oxidized accompanied by the release of heat, and in many processes, by-product energy from feedstock oxidation dominates purchased fuel and electricity. A classic example is the manufacture of nitric acid (qv) [7697-37-2] HNO. Ammonia (qv) [7664-41-7] burned in air on a catalyst at a pressure... 

Most gas turbine appHcations in the chemical industry are tied to the steam cycle, but the turbines can be integrated anywhere in the process where there is a large requirement for fired fuel. An example is the use of the heat in the gas turbine exhaust as preheated air for ethylene cracking furnaces as shown in Figure 4 (8). 

The hydrolysis of nitriles can be carried out with either isolated enzymes or immobilized cells. Eor example, resting cells of P. chlororaphis can accumulate up to 400 g/L of acrylamide in 8 h, provided acrylonitrile is added gradually to avoid nitrile hydratase inhibition (116). The degree of acrylonitrile conversion to acrylamide is 99% without any formation of acryUc acid. Because of its high efficiency the process has been commercialized and currentiy is used by Nitto Chemical Industry Co. on a multithousand ton scale. 

Dente and Ranzi (in Albright et al., eds.. Pyrolysis Theory and Industrial Practice, Academic Press, 1983, pp. 133-175) Mathematical modehng of hydrocarbon pyrolysis reactions Shah and Sharma (in Carberry and Varma, eds.. Chemical Reaction and Reaction Engineering Handbook, Dekker, 1987, pp. 713-721) Hydroxylamine phosphate manufacture in a slurry reactor Some aspects of a kinetic model of methanol synthesis are described in the first example, which is followed by a second example that describes coping with the multiphcity of reactants and reactions of some petroleum conversion processes. Then two somewhat simph-fied industrial examples are worked out in detail mild thermal cracking and production of styrene. Even these calculations are impractical without a computer. The basic data and mathematics and some of the results are presented. 

Few mechanisms of liquid/liquid reactions have been established, although some related work such as on droplet sizes and power input has been done. Small contents of surface-ac tive and other impurities in reactants of commercial quality can distort a reac tor s predicted performance. Diffusivities in liquids are comparatively low, a factor of 10 less than in gases, so it is probable in most industrial examples that they are diffusion controllech One consequence is that L/L reactions may not be as temperature sensitive as ordinary chemical reactions, although the effec t of temperature rise on viscosity and droplet size can result in substantial rate increases. L/L reac tions will exhibit behavior of homogeneous reactions only when they are very slow, nonionic reactions being the most likely ones. On the whole, in the present state of the art, the design of L/L reactors must depend on scale-up from laboratoiy or pilot plant work. 

Particular reactions can occur in either or both phases or near the interface. Nitration of aromatics with HNO3-H2SO4 occurs in the aqueous phase (Albright and Hanson, eds.. Industrial and Laboratoiy Nitration.s, ACS Symposium Series 22 [1975]). An industrial example of reaction in both phases is the oximation of cyclohexanone, a step in the manufacture of caprolactam for nylon (Rod, Proc. 4th Interna-tional/6th European Symposium on Chemical Reactions, Heidelberg, Pergamon, 1976, p. 275). The reaction between butene and isobutane... 

The alloys discussed are typical examples of the large number of proprietaiy high alloys used in the chemical industry. For more comprehensive lists and data, refer to the listed references. 

Due to their wide range of analytical challenges centralized analytical laboratories are required to adopt a series of QM systems simultaneously. For example, the Competence Center Analytics of BASF AG in Ludwigshafen is certified and accredited to operate under four different QM systems. Undoubtedly, QM systems play a vital role in a modern industrial analytical laboratory. The sale of many products of the chemical industry is not possible without a GLP-certified analytical laboratory. However, in practical tenus the different QM systems can potentially reduce the efficiency of the analytical process and lead to increased costs. 

The commercial exploitation of our increased understanding of protein stmcture will not, of course, be restricted to the pharmaceutical industry. The industrial use of enzymes in the chemical industry, the development of new and more specific pesticides and herbicides, the modification of enzymes in order to change the composition of plant oils and plant carbohydrates are all examples of other commercial developments that depend, in part, on understanding the structure of particular proteins at high resolution. 

Ribbon blenders are essentially self-contained mixers. They are employed in a variety of solid-liquid, solid-solid, and liquid-liquid blending applications in the chemical process industries. Examples include plastics, pigments, pharmaceuticals, specialty chemicals, confectionary. 

Basic process chemistry using less hazardous materials and chemical reactions offers the greatest potential for improving inherent safety in the chemical industry. Alternate chemistry may use less hazardous raw material or intermediates, reduced inventories of hazardous materials, or less severe processing conditions. Identification of catalysts to enhance reaction selectivity or to allow desired reactions to be carried out at a lower temperature or pressure is often a key to development of inherently safer chemical synthesis routes. Some specific examples of innovations in process chemistry which result in inherently safer processes include ... 

---