Originally Posted by suprfast
I really think you generalized this. Limiting or controlling the oxidizing agent(oxygen as it was referred to) is only part of the equation. The density of the fuel(charcoal) is another part of the equation. You can burn at the same temp but it would last for a different rate, vice versa. Simple BBQ math would also assume that too much oxygen without adequate room for the carbon monoxide to exit would cause the smoldering to cease. Like i said, i think you generalized and left quite a few steps out, as i have too generalized.
I am no chemist but I don't think density would play much of a factor as you say unless you were burning something like rocks or steel that would require a very high heat so more oxygen would be needed.
Yes if the proper amount of intake/oxygen with the proper amount of exhaust/carbon monoxide is applied then lump should burn very close to the same rate as charcoal. I always have leftover lump in my uds for the next cook. You can have all the exhaust you need but lack of oxygen/intake and the fire will still smolder.