Low temperature—long time, high temperature-short time liquefaction of coal: The Hokudai process

Abstract

A Japanese cola was hydrogenated in wash oil with fine iron dust and sulphur as catalyst under a reaction pressure of 12–13 MPa at 420 °C for 2 h and then at 500 °C for 0–20 min. The liquid yield boiling up to 600 °C amounted to 55–66 wt%. Pyridine conversion was ≈ 100 wt%, benzene conversion 82–90 wt% and n-hexane conversion 53–70 wt%. Compared with direct hydrogenation at 500 °C for 10 min the low temperature-long time plus high temperature-short time liquefaction process (the Hokudai process) is a very effective method for obtaining high liquid yield under relatively low hydrogen pressure without coking, using disposable catalyst and non-donor solvent.