Semin : A Technical Review of Compressed Natural Gas as an Alternative Fuel for Internal Combustion Engines
The natural gas is a promising alternative fuel which fulfills the strict engine emission regulations in many countries. In a compressed form, known as CNG (compressed natural gas) has long been used in stationary engines, but the application of CNG as a transport engines fuel has been considerably advanced over the last decade by the development of lightweight high-pressure storage cylinders. This is equipped with the engine conversion technology which is well established and the availability of the conversion equipment. For spark ignition engines there are two options, a bi-fuel conversion and a dedicated to CNG engine. For compression ignition engines converted to run on natural gas, there are two main options discussed, dual-fuel engines and normal ignition. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the CNG engines research and the development of CNG as fuel used are highlighted to keep the output power, torque and emissions of natural gas engines comparable to their gasoline or diesel counterparts. The high activities for future CNG engines research and development to meet future CNG engines is recorded in the paper.