How does one make biochar from banana leaves ?

How does one make biochar from banana leaves ? Im curious... also, what do you all think about carboard and paper charcoal as a source of biochar for our bins ?

I hope this might help:

I bought 4 #10 cans, opened them half way and froze the contents (tomato sauce) in gallon ziplock bags. I then filled each can with a different experimental ingredient: filbert nut shells, bamboo, small branches, cut to length, and banana leaves (shoved in as tight as I could get them).

https://permies.com/t/213651/Experimenting-small-scale-production-biochar

I don't think I'd bother making biochar from banana leaves. Way too much water in them. Good mix for compost though, or just lay them flat on the ground.

I make biochar from old hay, bean vines, corn stover, sunchoke stalks, hemp, and lots of other non-woody biomass. If you're using a flame cap method, you may need to do a lot of stirring to keep things hot. Or you can combine dry leaves with sticks and woody material for a more manageable burn. If you're using a retort, just try to pack them in as tightly as possible so you get a decent yield.

I was just thinking about growing hardy bananas  for the  leaves and trunks as an alternative to cardboard mulch.

I think the amount of charcoal one would get from a given retort volume of leaves,paper or cardboard is much less than a similar volume of woody material.

If you pack the leaves/paper/cardboard tightly I think their flatness would interfere with the free flow of gasses needed in a retort.

If you are using a flame cap method, I think it would take a lot of time/effort.
Even small diameter twigs take more time and effort to get the same amount of char than it would have taken with larger chunks of wood.

If you took the effort to process these materials into pellets, they should pyrolize quite nicely in a TLUD.

i understand you may just be working with what you have, but considering all the things i have around here, banana leaves i think would not make a large amount of biochar.
in terms of other "tropical materials", i'd probably get a lot more biomass from palm frond 'spines' (after you take the large fringes off, for weaving or ties or whatever-- they're very fibrous and can be seriously large) but definitely a heck of a lot more from coconut husks. banana stalks seem to have a lot of water in them and i'm not sure how they would burn, havent tested. also haven't tested coconut shells.