Abstract
This paper presents advantages and disadvantages of hydrogen, used in internal combustion engines. Also in this paper, are handled physical and chemical properties of hydrogen , obtaining methods, storage and transportation and using hydrogen in internal combustion engines as single fuel and as bi-fuel. For partial or total using as fuel in internal combustion engines, hydrogen must have all most the same properties as normal fuels. Thus, hydrogen must have high energetic performance must present some conditions at transportation and must not be a pollution source.
Keywords: Hydrogen, fuel, engines.