To carbonize something is to change it into carbon, usually by heating it without much air so it does not blaze away to ash. You can carbonize wood into charcoal. The word is a verb: it is the action. Someone carbonizes a sample; a process carbonizes plant matter over a long time. In British spelling you may also see carbonise; that is the same verb, not a different idea. Everyday English often prefers burn, char, or turn to charcoal. Carbonize is the more technical choice — chemistry, materials, industry. Though actually, it is not the same as to carbonate (to add bubbles). The two sit next to each other on the page and trick the eye, but one makes black carbon and the other makes fizz. If you need the name of the process, that noun is carbonization; if you need the result as a describing word, that is carbonized.

碳化（動詞）