One way to reduce CO2 in the atmosphere is to use biodiesel fuel (BDF) [1]. BDF has the advantage of low smoke combustion, since its molecules contain oxygen. Meanwhile, BDF has the drawbacks of high viscosity and a high pour point that make it difficult to use at low temperatures. Dimethyl ether (DME) can be made from biomass, as well as from natural gas or coal; therefore, it is regarded as one of the biomass fuels. DME has low viscosity and a low boiling point, and smoke-free combustion can be obtained, since it has no carbon-carbon bond [2]. On the other hand, it has the disadvantage of low lubricity due to its low viscosity. When these fuels are blended together, the weaknesses of the fuels can be overcome. The objective of this research is to show that blending these two fuels is an effective way of bringing biomass-derived fuels into practical use.
In this paper, the kinetic viscosity and pour point of the blended fuel at various blending ratios are compared with those of diesel fuel, and the appropriate blending ratios that can be used in ordinary environments and engines are discussed. BDF, BDF/DME, DME and diesel fuel were used in a DI CI engine, and the engine performance and emission characteristics were investigated. Based on these investigations, it is concluded that DME blending is an effective way to overcome the disadvantages of BDF.