Essentially yes.
Compare "charcoal kiln" with
"Conveyor Furnace". (Warning, annoying music)
Essentially, you build several lengths of very large diameter magma safe tubing to serve as passive radiators, and run a powered chain driven minecart track on it. You control the heat in the furnace through spacing the magma heated elements, and allow natural convection to drive air currents inside the furnace. This allows some portions of the furnace wall to act as heat sinks, while others to act as heaters, with heat holding at a lower temperature than pure magma. A reducing environment (Free of atmospheric oxygen, so chemically bound oxygen must combine with hot carbon atoms to form carbon oxide gasses, likewise with sodium and potasium ions, who are reduced and then turned into free ions from the heat, which gas out. Putting a chemical reservoir for these ions to be attracted to, like low sodium, high silicon oxide glass insulation, would effectively remove them from the equation.) is achieved by sealing load inside a
saggar, with a sealable lid, possibly with a one-way valve, and an unlockable keyhole.
Basically, when the load enters on the conveyor, It is stacked up inside a sealable airtight box that can survive the firing temperatures. Inside this box the alkaline earth absorbing material (Spun silicon oxide glass, made without flux) is set up as a series of walls arranged to come into contact with circulating gasses inside the saggar. The wood is stacked inside the saggar, and the lid is put on. The lid and saggar are designed to be held on via a simple twist-key type arrangement. The lid has a one-way checkvalve on it, to allow hot gasses to escape, but not to allow gasses back into the saggar. The conveyor conveys the saggars slowly down the track, where they get heated by IR exposure to the tube walls in the sections that are submerged in magma. Repeated flash heating, coupled with continuous movement of the conveyor, and the refractory nature of the saggars, produces a thermally controlled furnace environment suitable to controlled charcoal making.
Chemically:
Cellulose contains enough hydrogen and oxygen to almost completely destroy the load, even under reducing conditions.
C6H1206*(length of chain, since cellulose is just a complex repetition of simple sugar in a long chain.)
In addition to that, you have sodium and potassium ions, nitrate complex ions, and other things you need to remove, like chlorine.
You heat the material to just under the kindling point, so that the bound oxygen and hydrogen from the cellulose gasses off, leaving carbon behind. Because most of the energy liberated by this inefficient burn is immediately consumed by the formation of hydrogen and oxygen covalent bonds, and is not sufficiently hot to break those down again, (Eg, NOT on fire!), then those gasses escape from the load under pressure, and out through the checkvalve. At these low temps, we can use mild steel to make the valves and latches on the saggars. (they WILL degrade over time, but this should be an expected feature of the product lifecycle, and saggars should be inspected before reuse.)
Once the gassing has stopped, the checkvalve snaps shut, and the saggar continues down the track through the more intensely heated section.
There is now insufficient oxygen or hydrogen present inside the saggar to combust the carbon left inside. This stage matures the charcoal, destroys any thermally stable complex organic substances, and is what makes "activated charcoal" "activated". High ambient temps above the kindling point are reached inside the saggar, which garantees there is no longer any organic residues other than raw carbon matrices left behind. If this results in gas buildup, the checkvalve lets it out. This high temperature reducing environment is what liberates the sodium and potassium ions from the initial oxidation that occurs during the char formation stage. (In the previous stage, oxygen and hydrogen are boiled off, along with chlorine, and any thermally decomposable polyatomic ions, like nitrate. This leaves sodium and potassium oxides behind, which we now deal with.) The very high temps inside the saggar are now sufficient to break down the sodium and potassium oxides into carbon monoxide (reaction with load) and free sodium and potassium ions. These ions undergo an equilibrium reaction with the silicon oxide glass insulation netting installed inside the saggar, as well as with the saggar's walls. This removes them from the charcoal.
The saggar on the track is then slowly moved down a cooldown section, where cooling is controlled by rate of progression down the section of track, to prevent thermal shock in the saggars. (which would shatter them, exposing their still active contents to the atmosphere, and ruining it.)
By the time the saggars reach the far end of the system, they have cooled sufficiently to be left in ambient temp air, but are still too hot to handle by unprotected workers. The conveyor moves the saggars onto cooling racks, where they are allowed to slow cool in the controlled environment for at least 3 days.
They are then opened, saggars are unloaded, saggars are checked/repaired, (and in some cases, destroyed/recycled as raw material), and then returned to the input side of the continuous process furnace to be reloaded, and re-run.
Less "Modern" versions would involve simply dipping the wood in refractory clay impregnated bags, and then breaking the bags up when they reach the far end, and using the force of inserting new ware at the opening to drive ware down the line-- or even just using a dwarf powered chain drive to move the conveyor, where the dwarf itself controls the rate of progression down the line.
In the traditional process, clay shard, clay powder, and dirt are used in place of the saggar, and are the sodium/potassium ion mitigator, and atmosphere type regulator.