Thermokinetic and Thermodynamic Parameters for Catalytic Pyrolysis of Medium Density Fiber over Ni/Beta Zeolite

Abstract

Catalytic pyrolysis is an attractive alternative for converting biomass into energy and chemicals to replace fossil sources. This has encouraged the search for efficient catalysts that can directly remove oxygenated products during pyrolysis, since they are the main problem in the processing and use of the products obtained. The catalytic and non-catalytic pyrolysis of medium density fiber (MDF) over beta zeolite-supported nickel (3 and 5%) was performed using the biomass/catalyst of 1.0/0.2 ratio. The thermokinetic and thermodynamic parameters were determined using the isoconversional and non-isothermal methods of Flynn-Wall-Ozawa (FWO), Kissinger-Ahakira-Sunose (KAS) and Friedman. In addition, the master plots by the Criado method were used to determine the most suitable theoretical solid-state mechanism. The thermodynamic parameters were also obtained using the Friedman method. The results showed that the addition of the catalyst decreased the activation energy and affected the initial, final and maximum decomposition temperatures, which was related to the superficial acidic sites of beta zeolite that promote cracking and hydrocracking reactions. Nickel further decreased this parameter due to the activity of this metal in hydrodeoxygenation/deoxygenation, oligomerization and dehydration. The Friedman method provided the best correlation coefficient among the methods and was used to determine the thermodynamic parameters. The results showed that Ea increases in the order: MB3Ni < MB5Ni < MB < M.