The composition changes of hetero compounds in recycle solvent derived from the liquefaction experiment with Battle River coal using a lt/d pilot plant were examined.
In general, oxygen compounds increased and nitrogen compounds decreased. However, for some nitrogen compounds, the tendency of composition changes were different. Indole decreased immediately, but carbazole increased in recycle solvent. On the other hand, the decrease of o-ethylaniline was relatively slow.
In order to consider the mechanism for hydrodenitrogenation, the model experiments were carried out with the same N-iMo catalyst used in the liquefaction experiment of the pilot plant.
Carbazole was hard to be decomposed. Indole was hydrogenated to o-ethylaniline and succesively denitrogenated to yield ethylcyclohexane. In this reaction, indole was rapidly converted and the rate-determing step was presumed to be the hydrodenitrogenation of o-ethylaniline.
