Catalytic influence of iron oxide (Fe2O3) on coal pyrolysis and char combustion at various temperatures

Abstract

The conversion of coal into cleaner energy forms is essential for achieving sustainable development. This study investigates the role of Fe2O3 as a catalyst in enhancing the efficiency of coal pyrolysis and char combustion. A fixed-bed tube furnace (TF) was selected for pyrolysis, and a Thermogravimetric Analyzer coupled with Fourier Transform Infrared Spectroscopy (TG-FTIR) was used for combustion analysis. The produced syngas and tar were characterized using Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC/MS). Our results show higher volatile release volume (VRV) from coal with catalyst compared with without catalyst and the rise with temperature within the 600–1000 ℃ range. Although hydrogen production decreased with the addition of the catalyst, at 1000 ℃, the catalyst's impact was negligible. The catalyst notably facilitated the breakdown of heavy aromatic rings in tar, eliminating triple-bond aromatic structures. In contrast, tar from raw coal exhibited a 20% yield of such structures. Scanning Electron Microscopy (SEM) revealed a cubic structure of Fe2O3 in char, with an increased surface area compared to raw coal char (338.75 m2/g vs. 313.51 m2/g). TG-FTIR analysis indicated a lower activation energy for catalysts with char combustion. Overall, Fe2O3 improves tar structure, increases char surface area, and lowers activation energy.