Environmental effects of using methanol as a biofuel into the combustion chamber of a heavy-duty diesel engine

Methanol as a biofuel is an environmentally friendly substitute for pure diesel and can be obtained from biomasses. The use of biofuels such as methanol for the combustion process is associated with positive impacts on the environment. Using pure methanol or a blend of diesel/methanol fuel in motorized vehicles has been proposed by researchers. In this paper, pure methanol was injected into the combustion chamber of a ISM 370 HD diesel engine and the exhaust emissions were evaluated by using AVL FIRE CFD code software at four engine speeds (1200, 1400, 1600 and 1800 rpm). Additionally, the influences of EGR mass fraction and various injection timings were investigated. In order to validate the simulation results, incylinder mean pressure and rate of heat release (RHR) were compared with experimental data, and the results gave an acceptable agreement. The obtained results from the conducted simulation showed that the use of methanol fuel in the combustion chamber dramatically reduced the amount of exhaust emissions such as NO, soot, CO, and CO2 to 90%, 75%, 40%, and 26%, respectively. In addition, a mass fraction of EGR (20%) caused a reduction in the amount of exhaust NO to about 12%. It was determined that when a system is equipped with a fueling system at 3 deg before top dead center (BTDC), the exhaust NO and soot are reduced by 5.8% and 3%.

Keywords:

HD diesel engine , Exhaust emissions , EGR , Injection timing , Methanol biofuel