Catalytic testing, experimental procedure

Based on the ACR "virtual" catalytic tests and optimization can be performed using HRS (further details are given in the experimental part). Alternatively the whole experimental space can be mapped (see Fig. 1). After subsequent verification step a high resolution experimental space is created and further optimization takes place by HRS creating 1-3 more catalyst generations. After the last verification procedure the... 

Here, we report the application of this procedure for immobilizing Mucor miehei lipase. A catalytic test was aimed at producing esters by direct esterification reactions with a large range of carboxylic acids (from C4 to C16), and a diversity of alcohols (from C4 to C8). Several reaction model systems are analyzed in order to illustrate the kind of products that can be made by using an experimental preparation of lipase immobilized on POS-PVA particles. 

Thus, with the usual experimental procedures, a comparison of conversion data as a function of space velocity (residence time) does not tell us whether the kinetics differ from first order in the region of conversion below 50% for the range of order tested (zeroth to second). On the contrary, first-order kinetics can be used to represent the conversion as a function of residence time for a wide range of situations. Some investigators have been aware of this approximate first-order behavior of integral reactors, as shown by the statement that even complex catalytic systems approximate a pseudo- first order relationship when only space velocity is varied. .. (10). 

Testing. Studies of the catalytic activity and selectivity were conducted in a tubular unit reactor. Since this is a reactor consisting of a catalyst-packed tube of dimensions identical with those of a single tube inside a large-scale reactor, it becomes possible to reproduce the industrial conditions A thermocouple was placed in the catalyst bed, A detailed description of the experimental procedure has been presented elsewhere [4]. The tube was packed with two layers of catalyst (0.6 dm3 each). The total bed length was about 2.65 m. The feed was o-xylene of purity 98.4 wt.%. The air flow rate was 3.5 m3(STP)/h. The calcined catalyst samples were tested under conditions of continuous operation over a period of a couple of weeks during this period the concentration of o-xylene was varied from 20 to 70 g/m3(STP). 

The details of the synthesis of the V-MFI samples from acidic and alkaline media and the V-MEL samples from alkaline media have already been reported [6,7], The procedure used in the synthesis of vanado-aluminosilicates with BEA structure has also been reported [8], Similarly, the experimental methods adopted for the various characterization techniques and the catalytic tests have also been reported already [6,7],... 

Application of artificial neural networks (ANN) for modelling of the kinetics of a catalytic hydrogenation reaction in a gas-liquid-solid system has been studied and discussed. The kinetics of the hydrogenation of 2,4-DNT over a palladium on alumina catalyst has been described with feedforward neural networks of dififerent architectures. A simple experimental procedure to supply learning data has been proposed. The accuracy and flexibility of the hybrid first principles-neural network model have been tested and compared with those of the classical model. 

The Cu-Al-MCM-41 catalysts where prepared by standard ion exchange procedure and tested for the selective catalytic reduction (SCR) of NO with propane in the presence of O2, under the same experimental conditions employed for Cu-ZSM-5 catalysts with similar copper loading and Si/Al atomic ratio. 

A low decay of catalytic activity was observed for a catalyst sample after successive runs. To make sure that the activity level was the same for tests under different experimental conditions the catalyst sample was changed, following the procedure detailed in [5]. 

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