Antonio Chica

Discovery of new paraffin isomerization catalysts based on SO42−/ZrO2 and WOx/ZrO2 applying combinatorial techniques

Abstract Applying accelerated techniques for catalyst synthesis and testing and a stochastic experimental design, two catalytic systems based on SO42−/ZrO2 and WOx/ZrO2 were seen as active and selective for n-paraffin isomerization. After three optimization cycles, a new catalyst formulation based on promoted SO42−/ZrO2 with improved activity and selectivity has been found. Characterization of the best catalysts generated in each cycle has been done. Activity and selectivity of the best catalyst found has been tested in the isomerization of a simulated industrial feed composed by n-pentane, n-hexane and n-heptane. For the second best catalytic system, i.e. WOx/ZrO2, the influence of tungsten content, promotor (Ce), nature of the starting precursor salt (sulfate, nitrate or chloride), and catalyst calcination temperature was studied using a factorial design. The relevance of the interaction between salt precursor and calcination temperature is discussed.

Isomerization of C5–C7 n-alkanes on unidirectional large pore zeolites: activity, selectivity and adsorption features

The hydroisomerization–hydrocracking of nC5–nC7 is studied with a 12MR unidirectional zeolite (ITQ-4). Selectivity and kinetic parameters indicate that differences in pore topology are more important than acidity for determining isomerization selectivity. The adsorption of the paraffins is determined by van der Waals interactions.

Development of a low temperature light paraffin isomerization catalysts with improved resistance to water and sulphur by combinatorial methods

By means of combinatorial techniques (high-throughput catalyst preparation and testing systems, and a genetic algorithm (GA)), a search of new more tioresistant catalysts for low temperature isomerization of light paraffins has been conducted. After three evolving cycles catalysts have been found that not only are active and selective but also are more resistant to deactivation by water and sulphur than the corresponding conventional ones. The results have been reproduced in a pilot plant and the stability is shown.

Can artificial neural networks help the experimentation in catalysis

This work is focused on the practical application of artificial intelligent techniques in chemical engineering. Specifically, it describes an application of artificial neural networks for modelling the kinetics of a chemical reaction using methods not based in a kinetic model. Thus, neural networks have been used to model the behaviour of one catalyst under different reaction conditions for a specific reaction, i.e. n-octane isomerisation. Secondly, trained neural networks were used to model successfully another reaction with a similar reaction network.