Chlorination, fine chemical synthesis

Electrochemistry is widely used in industry, for example in effluent treatment, corrosion prevention and electroplating as well as in electrochemical synthesis. Electrochemical synthesis is a well-established technology for major processes such as aluminium and chlorine production there is, however, increased interest in the use of electrochemistry for clean synthesis of fine chemicals. The possible green benefits of using electrochemical synthesis include ... 

The industrial use of 1,3-dienes and of their electrophilic reactions has strongly stimulated the field in recent years. Because of the low cost of butadiene, abundantly available from the naphtha cracking process, very large scale applications in the synthesis of polymers, solvents and fine chemicals have been developed, leading to many basic raw materials of the modem chemical industry. For example, the primary steps in the syntheses of acrylonitrile and adiponitrile have been the electrophilic addition of hydrocyanic acid to butadiene24. Chlorination of butadiene was the basis of chloroprene synthesis25. 

A recent example of a product that is demanding in terms of process chemistry is a new herbicide from BASF. The seven-step synthesis requires bromination, chlorination, carbonylation, oxydation (with H2O2), hydrogenation, and a reaction with ethylene. As no fine-chemical manufacturer was in a position to offer the whole range of process technologies, the manufacture will be split between two fine-chemical companies. 

Owing to their numerous applications as fine chemicals for the synthesis of bioactive compounds such as pesticides and pharmaceuticals, isomerically pure chloroaromatics are very valuable materials. /-Butyl hypochlorite/HNa fauja-site in acetonitrile represents an efficient and highly regioselective system of mono-chlorination of a wide range of mono- and disubstituted aromatic substrates in mild conditions (Reaction S). 

Although Fritz Haber was a fine scientist and the success of his ammonia synthesis made him a rich man, he ultimately had a tragic life. At the start of World War 1 he joined the German Ghemical Warfare Service, where he supervised the use of chlorine as a chemical weapon during the battle of Ypres in France. This first use of a chemical weapon led to further tragic developments in chemical warfare and also to personal tragedy for Haber. His wife... 

As mentioned in the introduction, the effect of attrition on the particle size distribution is quite often as relevant as the attrition-induced loss is. The reason is quite obvious it is the strong dependence of the process performance on the bed particle size distribution. In the chemical industry, for example, the content of fines, i.e., the mass of particles below 44 microns, has often been observed to have a strong effect on the fluidized bed reactor performance, de Vries et al. (1972) reported an increase in the conversion of gaseous hydrogen chloride in the Shell chlorine process from 91 to 95.7% with an increase of the fines content in the bed material from 7 to 20%. The same effect was observed by Pell and Jordan (1988) with respect to the propylene conversion during the synthesis of acrylonitrile. They reported on an increase of the conversion from 94.6 to 99.2% as the fines content was changed from 23 to 44%. 

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