A study of methylcyclohexane cracking in a micro-channel reactor coated with M/SiO_2 (M=Fe, Co, Ni) catalysts under supercritical conditions

摘要

A series of transition metals M (M = Fe, Co, Ni) modified SiO2 catalysts were prepared by sol-gel method and coated on the inner wall of stainless steel tubes, in order to develop the micro-channel reactors. Cracking of methylcyclohexane (MCH) over the micro-channel reactors with coated catalysts was investigated under supercritical conditions. Meanwhile, the structure properties of the catalysts had been analyzed by some characterization technologies, such as N-2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of NH3 (NH3-TPD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and X-ray fluorescence method (XRF). The results showed that the cracking activity and endothermic capacity of MCH increase by following order: Thermal cracking Fe/SiO2 Co/SiO2 Ni/SiO2, which is responsible for the active components amount on the surface of SiO2 support. In addition, the gas yield, conversion and heat sink of MCH at 750 degrees C over Ni/SiO2 increased by 15.4%, 21.3% and 0.32 MJ/kg compared with thermal cracking, respectively.