With all its inefficiencies, the only real advantage of using hydrogen as a fuel source is that it can be burned without producing waste carbon to eneter the atmosphere. But extracting hyrogen directly from coal, by any process and regardless of other coproducts, still releases trapped carbon. And that defeats the only real point of moving to a "hydrogen economy".
The other stated purpose of the "hydrogen economy", energy independence, simply doesn't make sense for coal sourced hydrogen. Again, hydrogen's inefficiencies mean it would make more sense to make cars that burn coal directly. A coal driven car would release less carbon and yield more usefull energy than a car fueled by coal sourced hydrogen.
I want to be the first one on my block to drive a coal-powered car. Very cool.