Pyrolysis is the first step in the thermochemical conversion of any organic material. It plays a key role in coal conversion, where processes like combustion, gasification and hydrogenation include pyrolytic reactions as a starting step, and is the basic process in cokemaking. In the long history of industrial use of thermochemical coal conversion, various methods have been developed for feedstock characterization and for the main chemical reactions. Furthermore, approaches have been established to describe pyrolysis behavior quantitatively and to provide tools for reactor modeling. The main experimental techniques are reviewed and their relevance for the treatment of other solid feedstocks like biomass and wastes is discussed.