The potential of oxygenated fuels (n-octanol, methylal, and dimethyl carbonate) as an alternative fuel for compression ignition engines with different load conditions

The use of oxygenated fuels can significantly reduce emissions and maintain high thermal efficiency. However, few literatures have analyzed the effects of different fuels on engine combustion and emission performances under the same oxygen content. In this study, n-octanol, methylal (ME) and dimethyl carbonate (DMC) were selected to study the effects of oxygenated fuels on the engine combustion and emissions, controlling the oxygen content of the mixture fuel about 2.5%, under the condition of 0.4 MPa-1.2 MPa. The study found that in terms of combustion performance, the introduction of n-octanol improves the heat release rate, however, the use of ME and DMC decreases the heat release rate. In addition, the use of fuel NO45 has a higher thermal efficiency than ME13, DMC8, and D100. In terms of emissions, it is concluded that NO45 has the lowest carbon monoxide emissions, followed by ME13, DMC8, and D100. The use of oxygenated fuels as NO45, ME13, and DMC8 greatly reduces the soot emissions. From the combustion and emission performances of the experimental fuels, NO45, ME13 and DMC8 can achieve a good balance between NOX and soot emissions when the loads are 0.4 MPa-1.2 MPa.