Natural Gas as a Fuel for Dual-Fuel Automotive Engines. A Review

General information on natural gas properties, reserves, production and distribution is given. Application of natural gas to automotive vehicles and comparison with other gases as well as its application to spark ignition and compression ignition engines are discussed. As far as natural gas application to dual fuel engines is concerned, the influence of engine operating parameters (bmep, speed), control parameters (pilot diesel fuel quantity and timing, fuel-air equivalence ratio) and engine design (combustion chamber shape, supercharging) on efficiency, emissions, noise and cycle-to-cycle variations are discussed. Benefits of natural gas as a fuel for dual-fuel engines suggest its recommendation for automotive vehicles.