I’ve been given to understand that coal has to be burned in a stove designed for coal; burning it in a “wood” stove will eventually destroy the stove because it burns hotter than wood.
You can line a wood stove with some firebrick and build a grate on which to burn the coal. Not difficult. Another thing to take into consideration is that if you’re burning the coal on a pile of wood, the wood ash will tend to insulate the wood stove’s bottom from the coal too.
All stoves, wood and coal, should be lined with firebrick for longevity. I’ve gotten un-lined wood stoves hot enough to turn bright red when burning dried hickory.