Pyrolysis Kinetic of Basic Zinc Carbonate from Spent Catalyst and Preparation of Active ZnO by Microwave Heating

Abstract

The TG and DTG curves of self-made ZnO precursor were studied by the thermo-gravimetric analysis method in N2 atmosphere from 25°C to 650°C at the heating rate of 5, 10 and 15°C/min. The TG curve showed that the decomposition process started at about 150°C and finished at 300°C, in accordance with the temperature range of the decomposition from basic zinc carbonate to zinc oxide. The first level chemical reaction based on Coats-Redfern method was applied to estimate the activation energy of the decomposition. The correlation factor was about 0.99, and the calculated average activation energy was 33.89kJ/mol. Active zinc oxides were perpetrated by microwave heating at 350°C for 30min. Their composition and surface morphology were investigated by using scanning electron microscope and X-ray diffraction and its quality can reach the first-grade standard of HG/T2572-94.

Reactive adsorption desulfurization coupling aromatization on Ni/ZnO-Zn6Al2O9 prepared by ZnxAly(OH)2(CO3)z·xH2O precursor for FCC gasoline

“…Also, low crystal ZnO with high S BET (generally 30-70 m 2 /g or greater) is known as "active" ZnO, but it is not stable at high temperature. Some methods about the synthesis of "active" ZnO are available in present literature [17]. Pure ZnO is a rather traditional product, and many corresponding processes are available at present, but low S BET is a defect in bulk ZnO, while nanoparticle ZnO is born with weak thermal stability.…”