Dealkylation of coal-derived oil by the hydrogen generated from methanol decomposition

Several pure compounds were treated in a flow type reactor with methanol under normal pressure of nitrogen at 800–990 °C. Benzene derivatives with shorter alkyl chains can be effectively dealkylated to benzene or toluene, but benzene derivatives with long chains tend to cyclize to diphenyl, naphthalene or phenanthrene at high temperature. The main reaction of tetralin was dehydrogenation to naphthalene but decalin or perhydrophenanthrene cracked mainly to smaller ring compounds at lower temperature, although at high temperature, dehydrogenation was dominant. Heterocyclic ring compounds such as quinoline, benzothiophene and diphenyleneoxide were relatively stable. On the other hand, phenols were quickly degraded to CO and naphthalene above 800 °C.