Study of combustion and emission characteristics of a diesel engine operated with dimethyl carbonate

As an oxygenated additive, dimethyl carbonate (DMC) is usually blended with diesel fuel to improve combustion and reduce emissions of diesel engines. However, it is difficult to fuel diesel engines directly with DMC due to its low cetane number and high latent heat of vaporization. To study DMC combustion in diesel engines, this paper proposes an approach that combines internal exhaust gas recirculation (EGR) with a small injection of diesel fuel to ignite the DMC. Based on this approach, a two stroke, single cylinder diesel engine was developed. Preliminary studies demonstrated that this engine can be fueled with DMC with almost zero level of smoke and a low exhaust gas temperature. This DMC fueled engine has lower nitrogen oxides (NOx) emissions and 2–3% higher effective thermal efficiency than the engine operated with diesel fuel in moderate and high load zones. Further experiments were conducted on a set of advanced digital particle image velocimetry (DPIV) measurement system to study the DMC spray.