Can a charcoal generating process be a low carbon footprint incinerator? Noting that cellulose, hydrocarbons and carbohydrates are mostly C, H and O, it occurred to me that one might take low grade recyclables no longer welcome, and trash in general, and convert them to energy and carbon using a sophisticated incinerator that uses advanced sensors and computer monitoring, air and heating controls to burn the waste with little carbon footprint.
Heat generated could be recycled to start future  batches, and excess heat could drive power generation.
An interesting side discussion would be how to use the carbon without releasing it to the atmosphere.  Carbon fiber, filtration?
Another aspect is what sorts of other pollution is a problem, like sulfur compounds, carbon monoxide?
If kept at 200°C with water under pressure, any organic molecules break down after a while, that's called hydrothermal carbonisation, basically how coal was formed geologically
With pure sugar, the gross reaction is
$\ce{4CHO -&gt; 3C + CO2 + 2H2O }$.
Lignin is approximately $\ce{C31H34O11}$ (varies a lot of course), so
$\ce{C31H34O11 -&gt; 31C + 6H2 + 11 H2O}$
or
$\ce{C31H34O11 -&gt; 28C + 3CH4 + 11 H2O}$,
and other hydrocarbons, depending on the exact conditions.
You can also throw in finely shredded plastic, works the same.
The process obviously produces heat, and some $\ce{CO2}$, because once formed, it only very slowly reacts with hydrocarbon to carbon and water (you need higher temperatures and a potent catalyst for that).
Sulfur containing products can be handled by the same processes as in regular coal power plants, burn and wash out and turn into elementar sulfur.