A Comparative Study on Influence of Natural Gas Composition on the Performance of a CNG Engine

Abstract

Natural gas is the cleanest fossil fuel and it has high energy conversion efficiencies for power generation in internal combustion engines. Natural gases have varying composition depending on the place where they are produced. This paper studies the effects of natural gas composition on the combustion and emissions characteristics of CNG engines and presents the overall combustion characteristics obtained from running a 1.65 L, 4-cylinder EF 7 CNG engine. Engine power, Torque, BMEP and BSFC were measured under steady state operation conditions at full load conditions. The obtained simulation results were compared with experimental ones in the literature and showed that the CNG composition had a considerable influence on engine performance and fuel economy. A correlation has been proposed to help gain insight into the relationship between the Methane Number (MN) and engine power, and it provides a practical method for estimating the engine power when the composition of natural gases varies.