Space continuous catalyst regeneration

I. G. Farben also produced butene by butane dehydrogenation. A moving catalyst bed system was used in a tubular reactor. The total catalyst charge was 1.5 tonnes with a residence time of 4 h in the tubes. Yields of 85% at 20-25% conversion were obtained at a liquid space velocity of 2 h and 620°-650°C operating temperature. This was an impressive result for a new reactor design that has now been developed as the continuous catalyst regeneration process and is widely used in refineries. 

Denton et al. describe a procedure for aminating alkyl aromatic hydrocarbons, particularly toluene, which is converted to benzonitrile. Toluene and ammonia, at various reactant ratios and liquid space velocities, are passed at atmospheric pressure over a supported molybdenum trioxide catalyst at about 525-550 C. The conversion per pass is -10 per cent, and the yields are 60-85 per cent based on the toluene consumed. The process, as operated commercially, involves the continuous feed of toluene and NHj to one of two reactors followed by continuous removal of ammonia and toluene, for recycle, from the benzonitrile. Catalyst in one reactor is regenerated over a 3-6 hr period by oxidizing carbon deposits with air diluted with an inert gas, while the other reactor is on stream. 

This section describes the major process variables and their effect on vmit performance reactor pressure, reactor temperature, space velocity, H2/HC molar ratio, and catalyst type. The relationship between the variables and process performance is generally applicable to both SR and continuous regeneration modes of... 

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