Charcoal: we drive off all the water and hydrocarbons that normal vegetable-matter has to give us basically pure carbon without the crystal structure baggage of diamond or graphite. isit?
if so… the advantage is: not having to subtract the heat capacity of exhaust water (cause we drove off the hydrogen allready) from the net… isit?
I know it is basic, but I can’t seem to find a confirmation or denial of this thing that we people have been doing since the dawn of reproducible controlled fire.
I think the big advantage is that you have gotten rid of a big luminous flame in favor of a small nonluminous one mixed in with a big infrared radiator.
According to the internets the key to understanding is the flame / no-flame.
Charcoal burns the same way coal burns, without flames. Wood burns both ways, with flames at first then at the end a glowing bed of coals so-called. Burning with flames is less efficient. The wood has to be heated to convert to gas.
Softwoods like pine burn quick, almost all flames not much heat. Hardwood like Oak or Maple which are more dense put off flames at first but mostly just make a good bed of coals (as they are called) which put out big heat.