Methanol fumigation in compression-ignition engines: A critical review of recent academic and technological developments

The expanding energy demand, surging oil prices, depleting oil reserves, environmental pollution and climate change problems associated with the utilization of fossil fuels have revived interest to find out clean alternative fuels. Methanol is one of the most competitive alternative fuels due to its liquid nature, high oxygen contents, and high octane number and could produce from renewable sources. In this review, recent engine experimental and computational studies concerned with methanol fumigation on diesel engine were summarized. Technical and safety issue such as physical and chemical effect, environmental and health risk associated with the use of this technology were discussed. Modeling and simulation, engine performance and emissions, and recent advanced concept for methanol fumigated diesel engine were then reviewed respectively. At the beginning, the chemical and physical effect by the addition of methanol on the diesel fuels combustion were analyzed. The results showed that the fumigation of methanol could significantly prohibit the formation of PAHs. Then, for engine experiments, the effect of methanol fumigation on performance, combustion and emission characteristics of DMDF diesel engines were analyzed. It is examined that the fumigation of methanol fuel could reduce diesel engine emissions without adverse impacts on the performance of diesel engines. Further, new engine concepts such as RCCI operated with methanol fumigated diesel engine has also been summarized. Finally, this article puts forward some suggestions for the researches of diesel methanol dual fuel engine in the future.