We've many times documented and referred to West Virginia University's "West Virginia Process" for the direct liquefaction of Coal.
Again, our understanding of the West Virginia Process is that it utilizes, as do some others we've documented for you, the hydrogen donor solvent known most commonly as "Tetralin", which, again as we've documented, is an hydrogenated version of the long-known primary Coal oil, Naphthalene, to effect the hydrogenation and dissolution raw Coal.
A little more information concerning that WVU technology can be found, for one instance, in a fairly recent report we made, accessible via: WVU Hydrogenates Coal Tar | Research & Development | News; wherein is detailed: