I don’t think refining creosote is going to be as useful as you might think.
I also thought of being able to refine creosote into more valuable compounds but the reality is there isn’t really much point. My research suggests that wood-tar creosote (the variant I assume is being created) is little more than a bunch of different phenols, with the majority proportion being guaiacol and creosol. Neither of which are really better than creosote itself with their main uses in industry used mostly for flavoring and as a disinfectant. I couldn’t find anything on refinement of creosote other than an obscure paper in portuguese discussing the purification and enriching of wood tar using various chemicals.
Truth be told creosote is generally considered a waste product that makes a good wood preserver, it isn’t a very good fuel to begin with and I can’t find much on anyone refining it into something better.
Of course if anyone has further information I’ld love to hear it.