Mock-up plants

In the development of these processes and their transference into an industrial-scale, dimensional analysis and scale-up based on it play only a subordinate role. This is reasonable, because one is often forced to perform experiments in a demonstration plant which copes in its scope with a small produdion plant ( mock-up plant, ca. 1/10-th of the industrial scale). Experiments in such plants are costly and often time-consuming, but they are often indispensable for the lay-out of a technical plant. This is because the experiments performed in them deliver a valuable information about the scale-dependent hydrodynamic behavior (arculation of liquids and of dispersed solids, residence time distributions). As model substances hydrocarbons as the liquid phase and nitrogen or air as the gas phase are used. The operation conditions are ambient temperature and atmospheric pressure ( cold-flow model ). As a rule, the experiments are evaluated according to dimensional analysis. 

P. Trambouze [122, 123] from Institut Fran ais du Petrole (IFP) demonstrated on the basis of three petrochemical processes how mock-up plants enabled the acquisition of pertinent data for a reliable scale-up. This work will be presented here in greater detail because it shows that for a reliable scale-up of industrial plants in petrochemical industry - whose investment costs per plant often amount to a three digit million US sum - measurements on a large scale are often indispensable, leaving hardly place for a classical model scale-up. Seen from this point of view, the quotation in [122] is perfecty understandable ... 

In a mock-up plant the catalyst bed consists of the industrially used catalyst. As the liquid phase hydrocarbons and as the gas phase nitrogen are used. A geometric similarity cannot be kept because this would lead to a pilot reactor with the height of the industrial plant. The capacity of the pilot plant has to be reduced. In order to do... 

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