Problems with laboratory-scale processing

The solution of these problems is based on a simple idea the developed laboratory-scale process is used for manufacturing of a chemical product by parallelization of many small units. Although promising great advantages over scale-up, this procedure, denoted numbering-up , is not trivial by far. It cannot be carried out in a simple way due to the tremendous technological effort necessary a chemical plant with hundreds or even thousands of small-scaled vessels, stirrers, heaters, pumps. 

By their very nature, the vapor-phase oxidation processes result in the concentration of reaction heat in the catalyst zone, from which it must bfe removed in large quantities at high-temperature levels. Removal of heat is essential to prevent destruction of apparatus, catalyst, or raw material, and maintenance of temperature at the proper level is necessary to ensure the correct rate and degree of oxidation. With laboratory-scale apparatus, removal of this heat is relatively easy in some instances, it is even necessary to provide an external supply of heat in order to maintain the operating temperature at the proper level. With plant-scale operation and with reactions involving deep-seated oxidation, removal of heat constitutes a major problem. With limited oxidation, however, it may become necessary to supply heat even to oxidations conducted on a plant scale. 

Industrial heterogeneous catalysts and laboratory-scale model catalysts are commonly prepared by first impregnating a support with simple transition metal complexes. Catalytically active metal nanoparticles (NPs) are subsequently prepared through a series of high temperature calcination and / or reduction steps. These methods are relatively inexpensive and can be readily applied to numerous metals and supports however, the NPs are prepared in-situ on the support via processes that are not necessarily well understood. These inherent problems with standard catalyst preparation techniques are considerable drawbacks to studying and understanding complex organic reaction mechanisms over supported catalysts. (4)... 

A problem with this process is the decomposition of ADN as the temperature is raised above the melting point. The problem is that the melting point at 92°C is only 40°C below the temperature of decomposition. At 110°C the decomposition becomes autocatalytic after 15 minutes, at 98°C after a few hours. This is not a problem on the laboratory scale, where the melting period can be reduced to a few minutes. On the industrial scale, where hundreds of kilos of ADN should be melted in a batch, the time is much longer. It is likely that most explosives producers would hesitate and most likely refrain from scaling up this process unless nothing is changed. 

There are usually problems scaling up new fermentations as well as with translation of process-improvement data for well-established fermentations from laboratory operations to existing plant equipment.24 In general, fermentations are scaled up on the basis of achieving similar oxygen transfer capabilities in the plant equipment that proved to be optimal at the bench scale. 

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