Method of treating brown coal for liquefaction

摘要

A starting slurry composed of raw brown coal and a solvent is heated and pressurized, subjected to gas-liquid separation and dehydration and then to hydrogenation/liquefaction. The CO2-containing gas produced in the preheating/dehydration step and/or a CO2-containing gas supplied from outside the system is blown into the slurry in the above-mentioned preheating/dehydration step, whereby carbonate-forming metal components in the brown coal are converted to the carbonates thereof in advance. In this manner, the hydrogenation/liquefaction efficiency is improved, and stabilized long-term continuous operation is attained.