Energy & Fuels, Vol.23, No.7, 3652-3657, 2009
Catalytic Hydrogenation of HyperCoal (Ashless Coal) and Reusability of Catalyst
HyperCoal (HPC) is ashless coal obtained by a mild thermal extraction of coal to remove unextractable, heavy compounds, and minerals. The temperature and duration of HPC hydrogenation was systematically varied with and without solvent in an autoclave under hydrogen pressure. Unlike raw coal. hydrogenation of HPC in the absence of solvent proceeded without coke formation when the reaction was performed for 60 min at 450 degrees C in 10 MPa hydrogen (initial pressure). The hydrogenation catalyst was recycled five times with no detection of deactivation. Longer reactions at slightly higher temperatures (120 min at 460 degrees C), with replenishing the hydrogen. afforded a 90 wt % oil (hexane-soluble fraction) yield.