make up between to % of the dry weight of sweet potato roots. the sweet potato yields an important starch, which is used as a food starch in noodles etc. and technically for sizing textiles and papers, for the manufacture of adhesives and in laundries. the process of extracting and refining the starch...
there are lots of different ways to make this type of charcoal. basically, though, they all involve burning down coconut shells until they're mostly hot-burning carbon you need for fueling grills and other things. one way to carbonize coconut shells is to put it in a drum that locks out most of the oxygen...