Metal ores require mining operations.
Charcoal requires logging operations.
Both of these operations require fuel.
But, even if they didn't, and we somehow magically had a free supply of charcoal and Zinc Oxide, this process would still be a bust. Once you strip out from this process the water, Zinc, and all the other tomfoolery, it's basically just a fancy way of burning Carbon to make Carbon Dioxide. We'd be ahead of the game both for energy independence and for the environment, if we just burned the coal directly and ignored this whole Zinc sourced Hydrogen boondoggle.