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Process and reactors scaling

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shvet

Petroleum
Aug 14, 2015
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Please advise a worth books for process&reactors capacity scaling from a bench through lab and pilot to commercial unit and massive industrial application.

What scales are acceptable lab:pilot and pilot:commercial? 1000:1, 100:1, 10:1? What is max scale for stirring vessel reactor and why? 10m3, 100m3? What are typical capacities for each stage? What is the difference between continious and batch operation of reactor (scale, capacity, volume, budget etc.)? What should be budget for each stage?
 
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Shvet,

I can't speak to specific books regarding scale-up, but I can speak from personal experience.

Overall, scale-up is a finicky business. Geometric scaling almost never is applicable due to the non-linear relationship between reactor volume (vessel radius) and mixer flow/shear, heating/cooling surface area, etc.

As such, simplistic ratios (10:1, 100:1) are not really helpful. Often scales will be determine by other factors - budget available, supporting utilities/equipment footprint required for pilot scale, etc.

It is not unusual for a scale-up process to require an entirely different reactor design once a certain size is passed due to the non-linear scalings. Two examples, perhaps:
1. Batch reactors often utilize a jacket vessel for small reactors, but have to add internal cooling mechanisms (jacketed baffles, coils, etc) when a certain reactor size is reached.
2. A certain fixed-bed reaction may begin to develop hot spots as vessel radius increases, which lowers natural turbulent mixing times and HX area/unit volume. This non-linear scaling may require a change in reactor design to something like a multi-tube reactor or even a complete design change to a fluidized bed reactor.

Overall, the key for a successful scale-up is to determine the key factors for the process - mixing time, mixing shear rate, cooling/heating load, necessity of uniform temperature distribution over fixed-bed reactors, etc. These key factors can't be found in a book; you have to be knowledgeable in the process and select appropriate scales based on practical and process considerations.

 
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