The Taguchi method, a powerful tool to the optimization for quality, is used to improve the mechanical properties of a PCoMoAl hydrotreating catalyst in the impregnating and drying processes. An orthogonal array is selected to analyze the effects of the process factors, ie, impregnating temperature, impregnating time, drying temperature, and drying time. Through this study, not only can the main process factors that affect the mean strength and the Weibull modulus be found, but also the optimal factor levels can be obtained. Results show that the drying temperature is the most significant process factor affecting both the mean strength and the Weibull modulus. It has been shown that the mean strength, Weibull modulus, and mechanical reliability of the ydrotrating catalyst can be improved singificanuly with the optimization of the impregnating and drying process factors. Experimental results are also provided to confirm the effectiveness of the Taguchi method.

Monolithic catalysts were prepared by washcoating an alumina sol and then im pregnating Cu Mn Ag mixed oxides onto cordierite substrates. The effects of the preparation parameters including the Ag/Cu/Mn ratio, the total amount of active phase and the loading of washcoat, and the reaction conditions, e. g., the space velocity and the oxygen/toluene ratio on the catalytic performance for the corn bustion of toluene were investigated. It is shown that the Cu Mn Ag oxides are very active for the combustion of toluene and that the highest catalytic activity is achieved over a monolithic catalyst containing 14. 7wt% of washcoat and 21. 2 wt % of active phase with a Ag/Cu/Mn molar ratio of 13. 8/43. 1/43. 1. It is also seen that the optimum catalyst has a good catalytic stability and exhibits an excellent activity not only at a rather high space velocity but also within a wide range of oxygen/toluene ratios.

Mathematical models for the mechanical properties of a CoMoP/AI0 hydrotreating catalyst in the sulfidation process are developed with response surface methodology, A Doehlert design is performed tocollectively study the effects of sulfidation temperature, time and heating rate on the mean strength, Weibull modulus and pellet density, Analysis of variance reveals that the models developed for the mean strength and Weibull modulus are adequate, The validity of the models is also verified by experimental data, Analyses of response surfaces show that in the great part of the experimental domain examined, as the sulfidation temperature increases the mean strength decreases, while the Weibull modulus increases at first and then decreases, The middle level of the sulfidation time results in smaller mean strength and higher Weibull modulus, The Weibull modulus decreases with increasing heating rate; however, the effect of the heating rate on the mean strength is statistically less pronounced, It is concluded that there is a great potential for improving the catalyst mechanical reliability in the sulfidation process, while the pellet density does not vary significantly.

This paper presents a mathematical modeling and factorial analysis of the toluene combustion activity of acordierite monolith supported copper-manganese-silver mixed-oxide catalyst in the drying and calcination processes, usingresponse surface methodology. A central composite rotatable design is performed to collectively study the effect of drying temperature, calcination temperature and calcination time. Experimental results are provided to confirm the validity of the models developed.