Thermochemical conversion processes such as pyrolysis, steam gasification, and decarbonization of lignocellulosic materials have the potential to be cost competitive with conventional means of producing hydrogen. Hydrogen will play an important role in a future energy economy mainly as a storage and transportation medium for renewable energy sources. Hydrogen may become the favored energy carrier in a possible "greenhouse driven" future due to its lack of carbon dioxide emission at the point of use. It is shown that decarbonizing fossil fuels to hydrogen with carbon dioxide being stored in deep geological formations represents the least expensive way of producing carbon dioxide-free hydrogen.