Hydrogen is a pure and renewable energy source, which also has many excellent combustion properties for improving combustion and emission performance of Internal Combustion (IC) engine. Hydrogen has a high flammability, So that there is always risk of potential explosion. For avoid this hydrogen can store in three different ways: High pressure, Liquid storage, and metal oxide storage. In case of SI engine exhaust exergy is inversely proportional to the hydrogen addition. As hydrogen addition increases brake thermal efficiency was increases and emission of carbon dioxide (CO2) was reduced. However when engine lean out, carbon monoxide (CO) emission from hydrogen enriched engine was reduced. Oxides of nitrogen (NOx) emission increase with the increase of hydrogen addition due to the raised cylinder temperature. In case of CI engine (diesel engine), both NOx and soot emissions are taken under control with 15% and 40% energy content rates in the gas fuel compare to diesel only. Moreover gas fuel mixture reach a high value (75% energy content) as peak cylinder gas pressure decreases. With the addition of 75% hydrogen, diesel combustion characteristics of the engine converted into gasoline combustion. Thus it has been shown that hydrogen is good choice as an alternative engine fuel.
