Abstract
Fossil fuels are seized or stored underground for millions of years and are all non-sustainable resources. They are derived from non-renewable resources that cause irreversible degradation to the environment. Fossil fuel related prominent drawback of limited petroleum reserves, the concentration of global warming, harmful emissions and stores in specific areas. This has led to a situation where the use of alternative fuels such as natural gas, biodiesel, hydrogen, alcohol and dimethyl ether is under intense scrutiny. Compared to other candidates, DME (CH3–O–CH3) appears to have great potential and should be examined as fuel of choice for eliminating the dependency on petroleum. In particular, DME can be used as a clean, high-efficiency fuel for the diesel engines and exhibits minimum environmental impact due to its molecular structure which has no carbon–carbon bonds and much oxygen with respect to diesel fuel. Good burning characteristics, high thermal efficiency, non-toxicity, renewability and high cetane content make it a superior clean, green and scalable fuel as compare to that of fossil fuel. Sustainable application of DMEs requires critical evaluation of performance, efficiency, fuel injection characteristics, combustion and exhaust emission characteristics. Both pure and blended DME fuel is tested in combustion engine to acquire the optimal conditions of various parameters for extracting out maximum and efficient output. Hence, to maximize the sustainability of DMEs, the effects of fuel injection parameters and in-cylinder air motion, such as the pump plunger diameter, nozzle type, fuel injection timing, nozzle tip protrusion, nozzle opening pressure, fuel delivery angle, vapor pressure and swirl ratio on emissions and performance of the DME engine must be critically evaluated and compared with those of diesel engine. The present chapter focuses on adopting suitable changes in fuel injection strategies to enhance the emission and performance characteristics of DMEs fueled engine. Advance methods to sustain DME in the preexisting diesel engine system are discussed by modifying some effective improvements in the engine for getting maximum optimal output. Due to distinguished characteristics of DME from the diesel, the effects of fuel compressibility on compression work spray pattern, atomization characteristics are also compared, which may pave way for maximum exploration of DME as fuel for combustion engine through manipulation of fuel injection strategies.