Enhancement of bituminous coal pyrolysis for BTX production by Fe2O3/MoSi2-HZSM-5 catalysts

Abstract

The main objective of this work was to study BTX production for bituminous coal pyrolysis using co-modified HZSM-5 catalysts. A tube furnace reactor, and a thermogravimetric analyzer coupled with a mass spectrometer analyzer (TG-MS) were used to perform the pyrolysis characteristics of Ningxia bituminous coal with and without a catalyst. The collected products were determined by using a gas chromatography-mass spectrometry analyzer (GC–MS). In addition, an XRD analyzer and an N2-physical adsorption analyzer were employed to evaluate the Fe2O3/MoSi2 co-modified HZSM-5 catalyst. The results show that adding metal components into HZSM-5 improved the BTX production from bituminous coal pyrolysis, and the activity order of the catalysts was Fe2O3-MoSi2/HZSM-5> Fe2O3/HZSM-5 > MoSi2/HZSM-5>HZSM-5. The weight loss of coal increased by 10 % during pyrolysis in the presence of 10 wt.% (Fe2O3-MoSi2)/HZSM-5 catalyst with a Fe2O3/MoSi2 mass ratio of 1:1. The conversion rate of coal char was significantly increased, and especially the increase in the relative content of BTX products was 254 % in the liquid phase. In addition, the Ea of coal was lower by 8.253 kJ/mol during catalytic pyrolysis in the range of 350–600 ℃. A significant synergistic effect was observed between Fe2O3 and MoSi2 compositions on the production of BTX. A relative content and mass yield of 59.66 area% and 7.78 mg/(g·coal) of BTX were respectively achieved during the bituminous coal catalytic pyrolysis.