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Industrial practice

Table 5.28 gives the modifications in physical/chemical characteristics resulting from deeper and deeper hydrotreatment (Martin et al., 1992). The sulfur contents could thus be reduced to first as low as a few hundred ppm, then to a few ppm. The level of aromatics in the selected example drops from 39% to 7% while the cetane number increases from 49 to 60. Note here that such a treatment, possible through experimental means, does not correspond to current industrial practice because of its high cost and its very high hydrogen consumption. [Pg.265]

Satterfield C N 1991 Heterogeneous Catalysis in Industrial Practice (New York MoGraw-Hill)... [Pg.2714]

The sulphuric acid and ethyl hydrogen sulphate required in reactions 1 and 3 respectively are regenerated in reactions 2 and 4, but the water formed is retted in the acid mixture and ultimately results in such a dilution that the caiversion into ether is no longer efficient. Furthermore, some ethylene is always formed this partly polymerises to give materials capable of reacting with sulphuric acid and reducing it to sulphur dioxide. In industrial practice, sulphuric acid is sufficient for the production of about 200 parts of ether. [Pg.309]

Several polymerization techniques are in widespread usage. Our discussion is biased in favor of methods that reveal additional aspects of addition polymerization and not on the relative importance of the methods in industrial practice. We shall discuss four polymerization techniques bulk, solution, suspension, and emulsion polymerization. [Pg.396]

In current industrial practice gas chromatographic analysis (glc) is used for quahty control. The impurities, mainly a small amount of water (by Kad-Fischer) and some organic trace constituents (by glc), are deterrnined quantitatively, and the balance to 100% is taken as the acetone content. Compliance to specified ranges of individual impurities can also be assured by this analysis. The gas chromatographic method is accurately correlated to any other tests specified for the assay of acetone in the product. Contract specification tests are performed on product to be shipped. Typical wet methods for the deterrnination of acetone are acidimetry (49), titration of the Hberated hydrochloric acid after treating the acetone with hydroxylamine hydrochloride and iodimetry (50), titrating the excess of iodine after treating the acetone with iodine and base (iodoform reaction). [Pg.98]

In modem industrial practice, compositions often contain pigments, reinforcements, rheological modifiers, surfactants, and other materials in addition to fillers. These materials can function synergisticaHy in the system. Hence, more complex models are needed to predict the optimal filler loading. ExceUent discussions of filler loading and selection in plastics are given (9,10). [Pg.367]

Mona.Zlte, The commercial digestion process for m on a site uses caustic soda. The phosphate content of the ore is recovered as marketable trisodium phosphate and the rare earths as RE hydroxide (10). The usual industrial practice is to attack finely ground m on a site using a 50% sodium hydroxide solution at 150°C or a 70% sodium hydroxide solution at 180°C. The resultant mixed rare-earth and thorium hydroxide cake is dissolved in hydrochloric or nitric acid, then processed to remove thorium and other nonrare-earth elements, and processed to recover the individual rare earths (see... [Pg.543]

Reduction to Gaseous Metal. Volatile metals can be reduced and easily and completely separated from the residue before being condensed to a hquid or a soHd product in a container physically separated from the reduction reactor. Reduction to gaseous metal is possible for 2inc, mercury, cadmium, and the alkah and aLkaline-earth metals, but industrial practice is significant only for 2inc, mercury, magnesium, and calcium. [Pg.168]

This method, however, is not industrially practical because a large amount of dehydrating agent, such as ethyl orthoformate, is required to remove water formed in the reaction. Because water is an inhibitor of the reaction, the reaction system has to be kept under substantially anhydrous conditions. [Pg.459]

The rate of hydroformylation increases with increasing hydrogen and decreases with increasing carbon monoxide partial pressures (9), suggesting that rates of hydroformylation would be satisfactory at high H2 and low CO partial pressures. In industrial practice, however, high pressures of both H2 and CO ate required in order to stabilize the HCo(CO)4 catalyst at the temperatures necessary for practical rates (10). Commercial processes, for example, operate at >24 MPa (3480 psi) and >140 C. [Pg.466]

Industrial Practices forGaseous Ouygen Transmission and Distribution Piping Systems, Document CGA-4.4, Compressed Gas Association, Arlington, Va., 1993. [Pg.483]

In industrial practice it is generally the aluminum content of alums that is important. Because aluminum sulfate is widely available, other alums are more specialty items and are no longer produced in quantities comparable to those of aluminum sulfate (14). [Pg.176]

Batch reactors often are used to develop continuous processes because of their suitabiUty and convenient use in laboratory experimentation. Industrial practice generally favors processing continuously rather than in single batches, because overall investment and operating costs usually are less. Data obtained in batch reactors, except for very rapid reactions, can be well defined and used to predict performance of larger scale, continuous-flow reactors. Almost all batch reactors are well stirred thus, ideally, compositions are uniform throughout and residence times of all contained reactants are constant. [Pg.505]

Tke compounds contain the following generalized ingredients in the approximate proportions noted. Industry practice is to formulate starting with 100 parts by weight of the mbber (phr). Table 17 offers examples for various treads. [Pg.248]

Viscosity of Coal- Tar Pitch and Change with Temperature. Because pitch is mainly used as a hot-appHed binder or adhesive, the viscosity and its change with temperature are important in industrial practice. Some useful correlations, by which the viscosity of pitch at any temperature can be predicted, have been developed. The data on which such correlations are based may be from one of the fixed equiviscous points that characterize a pitch (Table 5). [Pg.341]

Catalysts. In industrial practice the composition of catalysts are usuaUy very complex. Tellurium is used in catalysts as a promoter or stmctural component (84). The catalysts are used to promote such diverse reactions as oxidation, ammoxidation, hydrogenation, dehydrogenation, halogenation, dehalogenation, and phenol condensation (85—87). Tellurium is added as a passivation promoter to nickel, iron, and vanadium catalysts. A cerium teUurium molybdate catalyst has successfliUy been used in a commercial operation for the ammoxidation of propylene to acrylonitrile (88). [Pg.392]

K. R. Feinberg, Deregulation of the Transportation Industry, Practicing Law Institute, Washington, D.C., Mar. 30—31,1981. Course handbook compilation of papers on transport deregulation and its effects. [Pg.265]

A wide variety of mammalian cells are used in industrial practice and to accommodate the diversity, a variety of cell culture technologies have evolved depending on the cell line and product characteristics. [Pg.230]

P.. Lewi, Multivariate Data Analysis in Industrial Practice, Research Studies Press,John Wiley Sons, Inc., Chichester, UK, 1982. [Pg.431]

R. E. Hucko and co-workers, "Status of DOE-sponsored Advanced Coal Cleaning Processes," ia R. R. K1 impel and P. T. Luckie, eds.. Industrial Practice of Fine Coal Processing, SME, Inc., Littieton, Colo., 1989. [Pg.265]

Evaluation of the Dusting Properties of Powder (or Other Solid Dyes). A number of methods exist to test this increasingly important behavior because of the greater awareness of working conditions and good industrial practice present today. [Pg.377]

A. L. Albright, W. L. Crynes, and W. H. Corcoran, Pyrolysis Theoy and Industrial Practice, Academic Press, Inc., New York, 1983. [Pg.447]

The prediction of drop sizes in liquid-liquid systems is difficult. Most of the studies have used very pure fluids as two of the immiscible liquids, and in industrial practice there almost always are other chemicals that are surface-active to some degree and make the pre-dic tion of absolute drop sizes veiy difficult. In addition, techniques to measure drop sizes in experimental studies have all types of experimental and interpretation variations and difficulties so that many of the equations and correlations in the literature give contradictoiy results under similar conditions. Experimental difficulties include dispersion and coalescence effects, difficulty of measuring ac tual drop size, the effect of visual or photographic studies on where in the tank you can make these obseiwations, and the difficulty of using probes that measure bubble size or bubble area by hght or other sample transmission techniques which are veiy sensitive to the concentration of the dispersed phase and often are used in veiy dilute solutions. [Pg.1636]

In industrial practice, the size-distribution cui ve usually is not actually construc ted. Instead, a mean value of the population density for any sieve fraction of interest (in essence, the population density of the particle of average dimension in that fraction) is determined directly as AN/AL, AN being the number of particles retained on the sieve and AL being the difference between the mesh sizes of the retaining sieve and its immediate predecessor. It is common to employ the units of (mm-L)" for n. [Pg.1659]

The following subsections discuss the basic considerations involved in various unit operations of solid-solid separation and describe present industrial practice and equipment in general use. [Pg.1756]

The simplest ultrafiltration is the stirred cell, a batch operation. The most compex is a continuous stages-in-series operation incorporating diafiltration. Industrial practice incorporates the full gamut of complexity. [Pg.2041]

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. [Pg.2079]


See other pages where Industrial practice is mentioned: [Pg.59]    [Pg.1]    [Pg.36]    [Pg.44]    [Pg.47]    [Pg.375]    [Pg.378]    [Pg.512]    [Pg.17]    [Pg.225]    [Pg.86]    [Pg.335]    [Pg.518]    [Pg.264]    [Pg.368]    [Pg.175]    [Pg.486]    [Pg.335]    [Pg.352]    [Pg.34]    [Pg.153]    [Pg.447]    [Pg.558]    [Pg.1564]   
See also in sourсe #XX -- [ Pg.115 ]




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