Examples of Industrial Processes

In this chapter, we will take a closer look at some large-scale induslrial processes that involve homogeneous transition metal catalysts [3, 6]. 

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Despite the technical emphasis of this chapter, we have included some examples of industrial processes. 

Throughout this text we will attempt to describe some examples of industrial processes that are either major processes in the chemical and petroleum industries or are interesting examples of fine chemicals, foods, or pharmaceuticals. The processes we will consider in this book are listed in Table 1-2. 

Figure 1 Examples of industrial processes employing reactive distillation (a) methyl ferf-butyl ether (MTBE) from isobutene and methanol (b) cumene via alkylation of benzene with propylene (c) ethylene glycol via hydration of ethylene oxide.

There are few examples of industrial processes with pure gas-phase reactions. The most common and oldest example is combustion. Although termed homogeneous, most gas-phase reactions take place in contact with solids, either the vessel wall or particles as heat carriers. With inert solids, the only complication is with heat transfer. Several of these reactions are listed in Table 19-1. Whenever possible, liquefaction of gas-phase systems is considered to take advantage of the higher rates of liquid reactions, to utilize liquid homogeneous catalysts, or to keep equipment size down. 

The selective oxidation of hydrocarbons with dioxygen is of immense industrial importance [ 1 ]. A general problem in this area is to obtain high selectivi-ties, particularly at high substrate conversions. The reasons for this are twofold oxidation can occur at different C-H bonds in a molecule, leading to a low primary selectivity, and the initially formed product is often more reactive than the substrate and is oxidized further, ultimately to carbon dioxide and water, leading to low secondary selectivities. Hence examples of industrial processes tend to involve the oxidation of hydrocarbons in which one particular C-H bond is significantly more reactive, for example, cumene hydroperoxide from cumene, and/or the product is relatively stable towards further oxidation, for example, maleic anhydride from n-butane, phthalic anhydride from o-xylene... 

Strategic importance of biocatalyzed synthetic transformations in terms of eco-compatibility and cheaper processes has been widely stressed previously. Among the developed biotransformations catalyzed by nitrilases or nitrile hydratases/ amidases systems, a special interest is focused toward stereoselective reactions able to give access to molecules otherwise impossible to obtain by classical chemical routes. Hereby, selected examples aim to offer an overview of research in this direction. Examples of industrial processes using nitrile hydrolyzing biocatalysts are also illustrated. 

Discussion Point DPI While there are many examples of industrial processes that depend on heterogeneously catalyzed hydrogenation reactions, there are very few (apart from the enantioselective processes) which are homogeneously catalyzed. Suggest some reasons for this. 

Transferases catalyze the transfer of functional groups such as methyl, hydroxymethyl, formal, glycosyl, acyl, alkyl, phosphate, and sulfate groups by means of a nucleophilic substitution reaction. They are not widely used in industrial processes however, there are a few examples of industrial processes that utilize transferases. 

Fundamental aspects of industrial catalytic processes are detailed including catalyst preparation, characterization, structure-property relationships, deactivation and defoul-ing, and catalyst regeneration methods. Examples of industrial processes that use different types of catalysts for chemical manufacture are also detailed. Identification and utilization of alternative resources for complementing our energy needs are addressed, which include renewable energy resources, oxygenated fuels, biofuels, fuel cells, and batteries. 

Table 2.12 Examples of industrial processes using solid base catalysts. Source adapted from Hattori [251].

Table 2.14 Example of industrial processes or processes under development based on asymmetric catalysis selected chiral ligands are shown at the end of the table. Source adapted from Blaser and Scmidt [312].

These two simple conversions will cover a large part of the stationary equipment. Gas fired home furnaces, water heaters, and stoves will all be handled in this simple manner at low cost. Coal and oil fired equipment will be less simple to convert. It will require the purchase of a low cost gas burner to replace the coal grates and oil injectors. Examples of industrial processes that can be converted in this simple manner include power plants, steel making, glass making, chemical processes, ore refining, and steam for heating. 

A brief overview of enzyme reactors used for application of immobilized biocatalysts in the laboratory and on the industrial scale is given in Fig. 7-35. Examples of industrial processes are given in [2] and [20]. 

Table 26.6 Examples of industrial processes that use heterogeneous catalysts.

In Table 5.3-3 some examples of industrial processes of chemical absorption are listed. These processes are often used for the separation of acidic compounds from... 

A variety of gases are used to transfer solids from one location to another nitrogen, air, chlorine, and hydrogen. When properly fluidized, solids respond like fluids. Solid transfer requires small, granular, porous solids that respond positively to aeration. Several examples of industry processes that use this procedure are modern plastics manufacturing (granules, powder, flakes), catalytic cracking units, and vacuum systems. 

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