Coal Pyrolysis in a Laboratory-Scale Two-Stage Reactor: Catalytic Upgrading of Pyrolytic Vapors

In situ upgrading of coal pyrolysis vapors over Ce/Zr/Ni and Ce/Zr/Ni/Zn catalysts was studied in a two-stage reactor. The catalytic effects of Ce/Zr/Ni and Ce/Zr/Ni/Zn on the pyrolysis products were examined, revealing that CO2, CO, and H-2 were dramatically increased and pyrolytic water was decreased when using these catalysts. The tar collected in the cooling traps showed a slight increase after catalysis. Compared to the no-catalyst condition, heterocyclic compounds and multicyclic aromatic hydrocarbons in the tar were significantly reduced, and benzene derivatives and aliphatics were increased. The molar ratio of H/C in tar was analyzed to further evaluate the tar quality. Possible reaction routes are proposed.