Reaction Processes and Their Equipment

In this section, industrial reaction processes are classified primarily with respect to the kinds of phases participating, and instances are given of the kind of equipment that has been found suitable. As always, there is much variation in practice because of local or historical or personal circumstances which suggests that a certain latitude in new plant design is possible. 

Ethylene is made by pyrolysis of hydrocarbon vapors in tubes of 50-100 mm dia and several hundred meters long with a reaction time of several seconds heat is supplied by mixing with superheated steam and by direct contact of the tube with combustion gases. 

Reactors to make polyethylene are 34-50 mm dia with 10-20 m long turns totalling 400-900 m in length. The tube is jacketed and heated or cooled at different positions with pressurized water. 

A flow reactor is used for the production of synthesis gas, CO + H2, by direct oxidation of methane and other hydrocarbons in the presence of steam. Preheated streams are mixed and react in a flow nozzle. Burning and quenching are performed in different zones of a ceramic-lined tower. 

Almost innumerable instances of such reactions are practiced. Single-batch stirred tanks, CSTR batteries, and tubular flow reactors are all used. Many examples are given in Table 17.1. As already pointed out, the size of equipment for a given purpose depends on its type. A comparison has been made of the production of ethyl acetate from a mixture initially with 23% acid and 46% ethanol these sizes were found for 35% conversion of the acid (Westerterp, 1984, pp. 41-58)  

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CLASSES OF REACTION PROCESSES AND THEIR EQUIPMENT 597 TABLE 17.11. Jacketed Vessels Overall Heat Transfer Coefficients... 

Classes of Reaction Processes and Their Equipment 592 Homogeneous Gas Reactions 592... 

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