Application of Methanol as Clean and Efficient Alternative Fuel to Engines with Compression Ignition

Methanol is difficult to be ignited by compression due to its low cetane number. The strategy of diesel–methanol compound combustion (DMCC) was proposed, which starts up with pure diesel fuel and switches to the mode of diesel–methanol dual fuel after the engine fully warms up. The strategy of DMCC will substitute methanol to diesel fuel up to 40% for new engine and 30% for retrofitting engine when it is applied to heavy-duty vehicle and constructive machine as well as marine power unit. The engines equipped with DMCC system are able to reduce NOx without assistance of selective catalyst reduction (SCR) urea system, as well as PM emission at the same time, which can meet the requirements of China V emission legislation and have the potential to meet the demand of China VI in future. The chapter introduces the strategy of DMCC, the main components dealing with methanol while applied to those engines mentioned above, and real examples on different power units. Additionally, the characteristics of diesel–methanol dual fuel (DMDF) combustion mode, emission control strategy, and system related to catalyst, retrofitting, and modifying engine from pure diesel to running DMCC mode are also illustrated. Again, it provides with the research results about the characteristics of DMDF combustion mode to assist the readers to understand the dual fuel combustion in depth as well as the examples applied to various power units, such as heavy-duty trucks, constructive machine, marine propeller, and locomotive engines.