Acid catalysis chemistry industrial applications

The field of reaction chemistry in ionic liquids was initially confined to the use of chloroaluminate(III) ionic liquids. With the development of neutral ionic liquids in the mid-1990s, the range of reactions that can be performed has expanded rapidly. In this chapter, reactions in both chloroaluminate(III) ionic liquids and in similar Lewis acidic media are described. In addition, stoichiometric reactions, mostly in neutral ionic liquids, are discussed. Review articles by several authors are available, including Welton [1] (reaction chemistry in ionic liquids), Holbrey [2] (properties and phase behavior), Earle [3] (reaction chemistry in ionic liquids), Pagni [4] (reaction chemistry in molten salts), Rooney [5] (physical properties of ionic liquids), Seddon [6, 7] (chloroaluminate(III) ionic liquids and industrial applications), Wasserscheid [8] (catalysis in ionic liquids), Dupont [9] (catalysis in ionic liquids) and Sheldon [10] (catalysis in ionic liquids). 

The synthesis of acetaldehyde by oxidation of ethylene, generally known as the Wacker process, was a major landmark in the application of homogeneous catalysis to industrial organic chemistry. It was also a major step in the displacement of acetylene (made from calcium carbide) as the feedstock for the manufacture of organic chemicals. Acetylene-based acetaldehyde was a major intermediate for production of acetic acid and butyraldehyde. However the cost was high because a large energy input is required to produce acetylene. The acetylene process still survives in a few East European countries and in Switzerland, where low cost acetylene is available. 

It is not sufficient merely to have such material on the libraiy shelves it must also be carefully indexed. All new books and pamphlets received are examined carefully for information that would not ordinarily be expected in such publications. In The Chemistry of the Non-Benzenoid Hydrocarbons (1922) by B. T. Brooks, for example, there are references to naphthenic acids, production of fatty acids by wax oxidation, and synthetic lubricating oils. In Volume VI of Colloid Chemistry (1946) edited by Jerome Alexander, there are chapters on the Geiger-Miiller x-ray spectrometer, electron microscopy, catalysis and its industrial applications, soil stabilization, polythene, and potential nuclear energy. Such information is typed on 3 X 5 cards on some books as many as forty or fifty cards may be required. In this way an extremely useful file of information has been built up that might otherwise be overlooked as valuable data sometimes appear in unexpected places. 

Metathesis of olefins, through the use of transition metal catalysis, is an important application in the petrochemical as well as in the polymer chemical industry for the production of special olefins and polymers (cf. Section 2.3.3). This chemistry is also applicable to unsaturated fatty acid esters, such as acetic acid methyl ester. However, the high price and unsustainability of the catalysts, compared with the fatty acids as substrates, have made commercial utilization not yet possible nevertheless they are of great interest for researchers in this field. 

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