Academic literature on the topic 'Intermediates (Chemistry) Photochemistry'

A large part of the chemical industry is concerned with organic chemicals from simple to highly complex structures. In dealing with relatively simple structures, there does not appear to be any need usually for a deeper understanding of chemistry than that to which an engineer is normally exposed. Most reaction engineering texts are written with this basic assumption. Catalysis, which is invariably an integral part of the reaction engineer’s arsenal, has been limited to the production of large volume chemicals which are often relatively simple in structure. Increasing attempts by chemists today to extend the use of catalysis to the production of medium and small volume chemicals has triggered a change in perspective that augers well for a closer liaison between chemists and engineers. We examine this a little further below by defining an organic chemicals ladder, and the merging roles of the two in exploiting this ladder, particularly for chemicals stacked on its intermediate rungs. Another change that is taking place is the increasing role of process intensification, nowhere more evident than in the production of organic chemicals. Process intensification means improvement of a process, mainly the reaction, by any possible means, to increase the overall productivity. This usually takes the form of reaction rate enhancement by extending known or emerging laboratory techniques to industrial scale production. These techniques can be engineering intensive, chemistry intensive, or both. Examples are the use of ultrasound (sonochemistry), light (photochemistry), electrons (electrochemistry), enzymes (biotechnology), agents for facilitating a reaction between immiscible phases (phase-transfer catalysis), microparticles (microphase engineering), membranes (membrane reactor engineering), a second phase (biphasing), combinations of reactions with different techniques of separation (multifunctional or combo reactor engineering), and mixing. Their use in the production of medium and small volume chemicals like pesticides, drugs, Pharmaceuticals, perfumery chemicals, and other consumer products is being increasingly explored both by industry and academe. Some of these techniques have progressed little beyond the laboratory stage, although they have been a part of the synthetic organic chemist’s repertoire for a number of years. Thus, in addition to the use of catalysis in its various forms, this book will also explore different techniques of reaction rate and/or selectivity enhancement.