2001 Volume 80 Issue 9 Pages 864-870
Coal liquefaction reactors are operated in high-temperature and high-pressure conditions, and the pulverized coal is fed to the reactor after making slurry using recycle solvent with wide boiling point range. Therefore, vapor-liquid distribution of solvent fraction in the reactors is one of the key issues to evaluate kinetic rate and reaction performance because it directly affects the actual residence time of the liquid phase in the reactors.
Using continuous coal liquefaction facility, which has systems for sampling the liquid phase in the reactor, 94 runs were conducted. The liquid samples from the reactors as well as the product liquids were collected and analyzed. The ratio of vaporized solvent fraction to total solvent fraction (Rv (Solv)) was calculated using these data. Rv (Solv) strongly depended on the reaction conditions, and was changed from 25wt% to 95wt%. Mainly, Rv (Solv) was affected by temperature, pressure, gas flow rate through the reactor. It also depended on boiling point distribution and properties of the solvent.
Vapor-liquid equilibrium calculation using SRK method was developed, and its results agreed well with Rv (Solv) obtained by the experiments. These results show that the vapor-liquid equilibrium calculation is useful for analyzing the reaction dynamics and designing coal liquefaction reactors.