Optimal Conditions for Demetallization of the Heavy Fraction of Low-Temperature Coal Tar of Shubarkol Komir JSC in the Presence of “Coal Shale” Catalytic Additive

Abstract

The optimal conditions for demetallization of the heavy fraction of coal tar from Shubarkol Komir JSC were determined by means of full factorial experiment. Optimal conditions for demetallization of the aforementioned fraction were found to be a proportion of “Coal shale” catalytic additive to the heavy fraction of coal tar with boiling point above 300 °С equal to 0.04, process temperature in the range of 420–430 °С, duration from 20 to 30 minutes and initial pressure between 3 and 5 MPa. Experiments conducted under these conditions demonstrated the demetallization rates of 87–89 %. Conversion of the heavy fraction of coal tar in hydrogen medium at pressure of 4.0 MPa and temperature of 420 °C was examined, with and without the use of the “Coal Shale” catalytic additive. The findings demonstrate that the incorporation of the “Coal Shale” catalytic additive is associated with a notable enhancement in the production of liquid hydrogenate, reaching up to 57 %. Atomic emission spectral analysis was used to investigate the content of rare and dispersed elements including Ge, Ga, Y, Yb, Zr, Nb the ash of the heavy fraction of coal tar and the “Coal shale” catalytic additive, as well as in the solid product of demetallization of the heavy fraction of coal tar using the catalytic additive. The results showed that the use of “Coal shale” as the catalytic additive leads to an increase in the content of Ga, Yb, Y elements by 3-3.8 times, and Zr — by 7.5 times compared to the initial heavy fraction of coal tar in the absence of the catalytic additive.