Effects of Rapid-heating and/or High-pressure Conditions on Coke Making, Examined Using a Synthetic Model Compound

Abstract

This study investigated the mechanisms by which rapid-heating and/or high-pressure conditions can improve the thermal fluidity of coal, using a synthetic compound as a model for low-molecular weight (Mw) compounds in coal. The compound had one quinoline ring and two naphthalene rings, C₃₆H₃₃N, Mw of 479, and a boiling point (bp) of ~520°C. Rapid heating (> 10°C/min) overcame the evaporation rate of the compound, whereas high pressure (> 1 MPa) increased the bp and suppressed the pyrolysis reaction. These conditions allowed the compound to remain until temperatures > 400°C, although it completely evaporated at 370°C under general heating conditions in a coke oven (3°C/min and 0.1 MPa). The effects of increasing the heating rate from 3 to 10°C/min at 0.1 MPa corresponded to the effects of increasing the pressure from 0.1 to 1.0 MPa at 3°C/min. The compound remaining at temperatures > 370°C can act as a mobile phase and hydrogen donor, thereby increasing the fluidity of coal. It can also serve as a reactant in the coking reaction and increase the coke yield.