What is the name of the process of conversion of wood to coal? 

Carbonization

The correct answer is option 1. Carbonization.

The carbonization process is used to turn wood into coal. Burning coal was simpler since it burned longer than wood and produced cleaner heat than wood.

The process of converting an organic material by pyrolysis or destructive distillation into carbon or a residue that contains carbon is known as carbonization. It frequently refers to the process of turning raw coal into coal gas and coal tar in organic chemistry.