Engine Performance and Exhaust Gas Emissions Characteristics of (CNG/Diesel) Dual-Fuel Engine

Single-cylinder diesel engines are widely utilized in Malaysia to generate electricity on small scales in open markets and rural areas. This paper represents a brief study carried out to: (1) understand the nature of exhaust emissions (NO_x, CO and CO₂) when adopting a dual fuel system using Compressed Natural Gas (CNG) in a single-cylinder, stationary diesel engine, and (2) compare the dual-fuel emission and engine performance results to those of diesel. The use of CNG is considered a possible solution for reducing the toxic emissions from these engines. This work shows that by using the dual fuel system, NO_x, CO and CO₂ concentrations in the exhaust gases were, on average, reduced by 54%, 59% and 31% respectively when the engine runs at maximum-load operating conditions. The average power output from the engine operating at dual fuel was 10% higher than that operating on diesel over the tested range of engine speeds.