Abstract
<div class="section abstract"><div class="htmlview paragraph">Currently, even the small diesel engines are required to reduce CO<sub>2</sub> emissions toward carbon-neutral society. One of the methods to realize this would be to use alternative fuels. Therefore, this research focuses on a liquid which is called MCH (Methylcyclohexane), it is expected as one of the "hydrogen carriers" that can transport hydrogen from foreign country efficiently. MCH is produced overseas by adding hydrogen to the toluene, and the hydrogen is extracted after transport to the destination. However, there is significant energy loss in extracting hydrogen process from MCH [<span class="xref">1</span>]. Therefore, it would be more hydrogen efficient use through MCH as fuel for the small diesel engines directly, rather than for power generation by extracting hydrogen, since it does not have that significant energy loss of MCH blended fuel in this research. MCH also has high potential for use as fuel, because it has sufficient calorific value on its own, it has low viscosity, it can be stored at room temperature and pressure, and it can use existing petroleum infrastructure [<span class="xref">2</span>, <span class="xref">3</span>]. Moreover, MCH is low carbon number compared with the diesel fuel, it has the potential for reducing CO<sub>2</sub> emission from the small diesel engines. In this research, engine tests are conducted with MCH blended with the diesel fuel, and it will be reported the fundamental engine test as indicator diagram and thermal efficiency and CO, HC, smoke emissions. MCH would be applied to the diesel engine without any adjusting of itself. The results have been mentioned that the blending rate of MCH with 10% volume would be appropriate for the performance of the small diesel engine.</div></div>