Product compositions from catalytic hydroprocessing of low temperature coal tar distillate over three commercial catalysts

Catalytic hydroprocessing of low temperature coal tar (LTCT) < 360 A degrees C distillate was performed over commercial Ni-W/gamma-Al2O3, Ni-Mo/gamma-Al2O3 and Co-Mo/gamma-Al2O3 catalysts in a fixed-bed reactor to produce clean liquid fuel. Experimental feedstock and liquid products were divided into twelve groups based on converted material with the molecules and saturation levels to investigate the effect of catalysts on reaction network of the main compounds in feedstock by GC/MS analysis. Meanwhile, the influence of catalyst component on the product composition like group composition, distribution of carbon number, heteroatom removal, gaseous and oil properties was also investigated. The experimental results showed that phenols were mainly transformed into cycloalkanes and alkylbenzene, while alkyl-naphthalenes were converted to phenyl cycloalkanes and phenyl olefins. In addition, total carbon number in a slightly decreasing tendency. The Ni-W/gamma-Al2O3 catalysts showed a higher hydrogenation activity and intermediate carbon number (C-9-C-16) selectivity, whereas the higher HDN and ring open activity was observed using Ni-Mo/gamma-Al2O3 catalyst. The highest percentage of sulfur removal (about 97.8 %) was reached over the Co-Mo/gamma-Al2O3 catalyst. Besides, methane was the predominant constituent in the light hydrocarbon gaseous product. And the properties of raw LTCT could be considerably upgraded after hydrotreatment.