John. Thank you for your comment. I appreciate that having lifted a plant, you might as well process the whole plant. My thought was that since plant sugar is the building block of growth, if you pick the sweetest plants, that are adapted or bred for sugar production, the sugar and carbon would be concentrated in its sugars. The other advantage is that sugar production is an "optimised" industrial process and therefore sugar, as a fuel source and food is readily available in the kinds of quantities I think I can persuade drivers to pay for.
Curious why you would advocate converting plants to charcoal. Is there a difference between sugar carbon and charcoal that I'm missing or can the same acid production method be used and on the whole plant rather than a slow airless burn? Charcoal production isn't feasible on any sensible scale in South East England hence my interest in acid as a short cut to carbon production.
Any further thoughts?