Large-scale industrial processes

Table 1. Some Large-Scale Industrial Processes Catalyzed by Surfaces of Inorganic Solids ...

F. Haber s catalytic synthesis of NH3 developed in collaboration with C. Bosch into a large-scale industrial process by 1913. (Hater was awarded the 1918 Nobel Prize in Chemistry for the synthesis of ammonia from its elements Bosch shared the 1931 Nobel Prize for contributions to the invention and development of chemical high-pressure methods , the Hater synthesis of NH3 being the first high-pressure industrial process.)... 

The growth of industrial scale biotransformation processes has increased significantly over recent years with more than 130 reported in 2002 [1]. Major activity is focussed on the production of chiral pharmaceuticals although a number of large scale industrial processes have been developed for the food and agricultural industries. 

The flow reactor is typically the one used in large-scale industrial processes. Reactants are continuously fed into the reactor at a constant rate, and products appear at the outlet, also at a constant rate. Such reactors are said to operate under steady state conditions, implying that both the rates of reaction and concentrations become independent of time (unless the rate of reaction oscillates around its steady state value). 

From a fundamental point of view, it would be very interesting to find a way to achieve an electrochemical reduction of another very inert compound—the reduction of molecular nitrogen to ammonia—a reaction that is analogous to the well-known large-scale industrial process of ammonia production. Some papers on... 

The acid-catalyzed addition of water to the double bond of an alkene is a method for the preparation of low molecular weight alcohols that has its greatest utility in large-scale industrial processes. 

Chromatography also has its own special equipment requirements that vary dependent on the type and scale of the procedure, and the efficiency level desired from the separation. This paper deals predominantly with chromatographic separations as they pertain to large-scale industrial processes and their special needs and considerations. 

As in all large-scale industrial processes, the formation of the cellulose esters involves recovery of materials. Acetic anhydride is generally employed. After reaction, acetic acid and solvent are recovered. The recovered acetic acid is employed in the production of additional acetic anhydride. The recovered solvent is also reintroduced after treatment. 

The transition metal-catalyzed addition of the Si-H bond of a hydrosilane across a C=C or C=C bond is a transformation of considerable importance in both large-scale industrial processes and in small-scale organic synthesis.Perhaps the most common industrial application of catalytic hydrosilylation is the platinum-catalyzed cross-linking of vinylsilane polymers with hydrosilanes. The interest in catalytic hydrosilylation in organic synthesis... 

Catalysts have been used in the chemical industry for hundreds of years and many large-scale industrial processes can only be carried out thanks to the presence of catalysts. However, it is only since the 1970s that catalysis has become familiar to the general public, mainly because of developments in environmental protection, such as the well-known and widely used catalytic converter for automobiles [1]. 

Industrial Applications. Several large scale industrial processes are based on some of the reactions listed above, and more are under development. Most notable among those currently in use is the already mentioned Wacker process for acetaldehyde production. Similarly, the production of vinyl acetate from ethylene and acetic acid has been commercialized. Major processes nearing commercialization are hydroformylations catalyzed by phosphine-cobalt or phosphine-rhodium complexes and the carbonylation of methanol to acetic acid catalyzed by (< 3P) 2RhCOCl. 

Pseudoliquid-phase catalysis (bulk type I catalysis) was reported in 1979, and bulk type II behavior in 1983. In the 1980s, several new large-scale industrial processes started in Japan based on applications of heteropoly catalysts that had been described before (5, 6, 72) namely, oxidation of methacro-lein (1982), hydration of isobutylene (1984), hydration of n-butene (1985), and polymerization of tetrahydrofuran (1987). In addition, there are a few small- to medium-scale processes (9, 10). Thus the level of research activity in heteropoly catalysis is very high and growing rapidly. 

Conventionally the reaction is performed in two stages, the so-called high- and low-temperature water-gas shift. In large-scale industrial processes, Fe203/Cr203 catalysts are applied for high-temperature shift (which is then performed between... 

The use of immobilized biocatalyst in large-scale industrial processes is presently a widespread technique. Thus, the description of the mass transport in spherical particles as support material is well known. Ferreira et al. [32] summarizes the most important variables and equations for the mass transport, the effect of the reaction rate on the concentration distribution in the spherical particles. 

The use of recombinant microorganisms for cofermentation is one of the most promising approaches in the field of bioethanol production, though their use for large-scale industrial processes still requires fine-tuning of the reliability of the entire process (2). The technical hurdles of cofermentation increase when real biomass hydrolysates have to be fermented. In fact, whatever the biomass pretreatment, the formation of degradation byproducts that could inhibit the fermentation usually requires the addition of a further detoxification step. Therefore, the production of ethanol from hydrolysates should be considered in its entirety, from the optimal pretreatment to the choice of the proper fermentation process. 

The organosilane modification of silica is of great importance in science and industry. Because of its widespread applications, there is a lot of interest in the underlying reaction mechanisms in the modification process. A fundamental understanding of these mechanisms can lead to an improvement of known applications and the development of new ones. Thus, fundamental knowledge supports industrial development. Mechanistic studies are performed on model systems with low complexity. Therefore organic solvent and vapour phase modification procedures are mostly used. Thus, the concentration of the reactants and the presence of water in the system may be easily controlled. From a careful description of the simple model systems, extrapolation towards large-scale industrial processes may be performed. 

All commercial caprolactam processes are based on benzene or toluene. These processes employ cyclohexanone, cyclohexane or toluene as starting materials. Large-scale industrial processes are multistage processes in which ammonium sulfate and sometimes organic compounds are formed as byproducts. At least seven processes are used commercially254,266. And each of these processes still has room for improvement. 

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