Some Significant Industrial Examples

One obvious area for the use of sonochemistry is the amelioration of conditions required for the synthesis of temperature-sensitive products. The first large-scale example reported provides a perfect example to illustrate the scaling-up potential of the technique. The procedure relates to the synthesis of naphthoquinone derivatives as pharmaceutical intermediates (Fig. V7)P- Here sonication generates higher yields and uses milder working conditions (lower temperature, shorter procedure, higher purity and selectivity). 

The power requirements are not large (400 W for 400 kg of final product in a 4-m batch) and therefore are rather interesting. Moreover, in the process, ultrasound 

78 Gelzhauser, P. German Patent DE 3.739.979 Chem. Abstr. 1990,112, 42195d. 

80 See, however, Gaplovsky, A. Donovalova, J. Toma, S. Kubinek, R. Ultrasonics Sonochemistry 1997,4,109-115. 

82 Ikeda, N. Sugishima, N. Fujii, Y. Ikuta, S. Inoe, A. ]pn. Kokai Tokkyo Koho P 63,270,635 Chem. Abstr. 1989,110,156533b. 

---

Of some concern in this field is the issue of intellectual property, as there are a large number of patents protecting the area in terms of the preparation, identities and uses of these solvents. For example, one patent claims broad coverage of cheap phosphonium ionic liquids, and this might prevent their use in many applications. However, the large number of patents also demonstrates significant industrial interest in these media and industrial processes using them are now online. ... 

In both the synthetic organic laboratory and industry, the first and foremost procedure for the preparation of oxiranes is the direct oxidation of alkenes. Significant new results have been achieved in the development of methods of oxidizing alkenes in the liquid phase. The major aim is the attainment of an oxidation reaction under the mildest possible experimental conditions, which allows an increase in the selectivity of oxirane formation and permits the selective oxidation of more sensitive compounds. Since the various methods of preparing oxiranes were reviewed quite recently, the individual oxidation procedures will be mainly illustrated here with some more recent examples. Surveys concentrating on stereo-controlled epoxidations and assymmetric synthetic methods have been published. "... 

It should be possible to use compressed metal powders as, for example, a catalytic filter, but the present authors are not aware of any industrial examples of this. Raney metals powders, however, have been employed in some liquid-based processes in shallow beds through which reactants pass. Because Raney metals are fine grained, pressure drop can be a problem so it is more common to use them in an unstructured way in slurry reactors, as, for example, formerly in the oils and fats industry [3]. Raney metals can have high surface areas when freshly prepared, but this decreases quickly in use, particularly when exposed to elevated temperatures. Pressure drop considerations are less significant for beds of metal granules, but there is less effective use of metal than with fine powders. For granules, surface areas in the region of 30-35 cm g are typical for silver used in... 

There is a long history of ACS concern over conditions at the Industrial-Academic Interface - a concern probably no less enduring than the communities whose juxtaposition creates and maintains that boundary surface. In recent years, for example, the ACS s OPERATION INTERFACE generated over 60 local conferences on the subject the 1979, 1980 and 1981 ACS Presidential Conferences were either devoted to it or addressed it to some significant degree several ACS task forces on industrial-academic cooperation were formed and most are still active. 

There is an important categoiy of free-radical emulsion polymerizations where the hydrophobic polymer does not dissolve in its own monomer [3-6] or is only sparingly soluble in its own monomer [3]. Some examples of these kinds of polymerizations are the emulsion polymerization of fluorinated monomers (e.g. tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), 1,2-difluoroethylene) [4,5] and acrylonitrile [6]. The polymers formed by these polymerizations all have significant industrial importance, particularly as engineering polymers (e.g. Teflon, aciylonitrile-butadiene-styrene copolymer (ABS)). As a result much of the research into these processes remains outside the public domain. 

The purpose of this analysis is to correlate some accessible quantum chemical results with physico-chemical properties of some aromatic compounds. The systems presented are hydrocarbons (aromatic aimu-lenes), amines, moleeules, ions, hydroxyarenes, and heterocycles with nitrogen, all of them selected according to their industrial significance. For example, by diazotization and coupling reactions the aromatic amines and phenols lead to azo dyes. The heterocyclic compounds take part in... 

Some polymers from styrene derivatives seem to meet specific market demands and to have the potential to become commercially significant materials. For example, monomeric chlorostyrene is useful in glass-reinforced polyester recipes because it polymerizes several times as fast as styrene (61). Poly(sodium styrenesulfonate) [9003-59-2] a versatile water-soluble polymer, is used in water-poUution control and as a general flocculant (see Water, INDUSTRIAL WATER TREATMENT FLOCCULATING AGENTs) (63,64). Poly(vinylhenzyl ammonium chloride) [70304-37-9] h.a.s been useful as an electroconductive resin (see Electrically conductive polya rs) (65). 

Oxychlorination of Methane. The oxychlorination of methane with HCl and oxygen has received some attention since the 1970s (22—24), though there are no examples of an industrial process. This can be a coproduct process making all the chloromethanes in significant yields or one that makes primarily methyl chloride. Interest in this route has increased in the past few years because of progress in the methane to light hydrocarbons process. 

Heterogeneous reactions of industrial significance occur between all combinations of gas, liquid, and solid phases. The solids may be inert or reac tive or catalysts in granular form. Some noncatalytic examples are listed in Table 7-11, and processes with solid catalysts are listed under Catalysis in Sec. 23. Equipment and operating conditions of heterogeneous processes are covered at some length in Sec. 23 only some highlights will be pointed out here. 

---