Progress of coal liquefaction was analyzed in the first reactor of 1t/d Process Supporting Unit (PSU) for development and optimization of the NEDOL Process. The reaction progress was evaluated by analyzing the composition of reactor content directly sampled as well as that of sample from the gas-slurry separator immediately after the reactor.
The yield of oil, i.e., the hexane-soluble fraction, in the reactor was found to reach nearly 55wt%daf, which amounted more than 95% of the final yield attained in the normal operation using the three reactors. Increase in the reaction temperature and/or the feed ratio of gas to slurry (G/L) resulted in a prolongation of the actual residence time of slurry in the reactor with appreciable decrease in the residue yield and increase in the oil yield. This was reasonably explained by a mechanism that the increased temperature and/or G/L would accelerate evaporation giving rise to a slight increase in the gas-phase holdup and a significant decrease in the slurry-phase flow rate in the reactor. Based on those results, progress of coal liquefaction in the reactor was kinetically analyzed, focussing on change in yield of IOM (Insoluble Organic Matter).
