Optimization of CO2 reforming of methane process for the syngas production over Ni–Ce/TiO2–ZrO2 catalyst using the Taguchi method

Abstract

In the present study, Taguchi method-based design of experiment with L9 orthogonal array was implemented to optimize the process conditions for CO2 reforming of methane over the Ni–Ce/TiO2–ZrO2 catalyst. The catalyst composition, catalyst reduction temperature, reaction operating temperature, and the CO2/CH4 ratio of the reactant gas were the control parameters. The performance index was considered as the response of the Taguchi experiment. The performance index was calculated by considering the product gas H2/CO ratio, deactivation factor, carbon deposition, and maximum CH4 conversion. The catalysts were prepared in two steps using the evaporation-induced self-assembly and urea deposition-precipitation methods. The catalysts were characterized in their fresh and spent stages using various techniques like X-ray diffraction, N2-physisorption, H2 temperature-programmed reduction, inductively coupled plasma-mass spectroscopy, Scanning electron spectroscopy, Transmission electron spectroscopy, and Thermogravimetric analysis. The results showed that the operating temperature had the principal effect on the performance index. The optimal conditions from signal/noise ratio analysis were Cat3 catalyst with Ti/Zr ratio of 1:3, catalyst reduction temperature of 600 °C, the operating temperature of 800 °C, and feed gas ratio as CO2/CH4 = 2. Higher Zr content in the catalyst support and the lower reduction temperature favor enhancing the performance index.