CNG ENGINES FOR VEHICLE APPLICATIONS: A COMPARATIVE AND CRITICAL STUDY

Italy has been a pioneer in using natural gas as a fuel for internal combustion engines: at the end of 1939, more than 1000 buses, 1200 trucks and 3000 passenger cars were running on natural gas. After a gradual contraction in the postware period, the use of natural gas become again important in 1973, because of the first energy crisis. Inthe nineties, the environmental concern contributed a lot to a renewed push in using natural gas. In fact the decrease of particulates matter, ozone forming pollutants, i.e. nitrogen oxides and reactive hydrocarbons, and unregulated pollutants, like benzene and polynuclear aromatic hydrocarbons. appears possible with internal combustion engines running on natural gas.