Kinetic study of coke decomposition formed on modified Beta zeolite with zinc and lanthanum

The sulfur-reducing catalytic additives are added to the FCC catalyst to reduce the amount of sulfur compounds in the reaction products that are of interest. However, like the main FCC catalyst, the catalytic additive also undergoes deactivation by coke, which makes it important to determine the characteristics of this by-product in this class of catalysts. Therefore, the kinetic study of the thermoxidation of coke formed on the catalysts was investigated after the catalytic cracking of cyclohexane containing 2% sulfur, from benzothiophene, by determining the activation energy. The catalysts were created by wet impregnation of lanthanum and zinc into commercial Beta zeolites, and they were then studied using X-ray fluorescence (XRF), X-ray diffraction (XRD) and infrared spectroscopy (FTIR) to investigate potential structural alterations. They demonstrated that Beta zeolite did not significantly change the structure as a result of the addition of zinc and lanthanum. The properties of the coke and the amount that had been generated on the catalysts were assessed using Raman spectroscopy and thermogravimetry on the coked catalysts. The activation energy needed to regenerate the catalysts was calculated using the Ozawa-Flynn-Wall and Friedman isoconversional methods using thermogravimetric mass loss curves and heating rates of 10, 20, and 40 K/min. The results showed that the original Beta zeolite had the highest activation energy for coke combustion, whereas the lanthanum-modified Beta zeolite had the lowest activation energy. Additionally, it was discovered that the degree of coke disordering and activation energy have an inverse correlation.