Effect of metal oxide nanoparticles on the evolution of valuable gaseous products during pyrolysis of Turkish low-rank coal

Abstract

In this study, TiO2 and ZnO nanoparticles were synthesized via solvothermal method and used as a catalyst for low-rank coal (LRC) pyrolysis to improve the gaseous product quality and yield. Effects of nanocatalysts on the yields of pyrolysis products distribution were discussed in details. Different reaction temperatures (400–700 °C) and catalyst to LRC ratios (1, 5, and 15% w/w) were examined. The optimum catalyst to LRC ratio was found as %1 by weight, while optimum pyrolysis temperature was determined as 700 °C. The gaseous products (hydrogen, methane, carbon dioxide, carbon monoxide and C2–C4 hydrocarbons) were characterized by micro gas chromatography (μGC) to understand the catalytic ability of TiO2 and ZnO nanoparticles while the pyrolytic oil (tar) was characterized by gas chromatography–mass spectroscopy (GC–MS) as well as Fourier-transform infrared spectroscopy (FT-IR). Through the thermogravimetric analysis method (TGA) weight loss was obtained in the samples.H-ZSM-5 as well-known pyrolysis catalysts was also used for the comparison purposes. The results showed that gaseous product yields were increased drastically in the presence of nano TiO2 and nano ZnO.