Experimental Study of the Combustion and Emission Characteristics of Lower Alcohols in a Constant Volume Vessel

The synergistic effects of chain length, functional group position, and equivalence ratio on the combustion and emission characteristics of lower alcohols were investigated in a constant volume vessel at phi = 1.0, phi = 0.8, phi = 0.6, phi = 0.4, and P-init = 1.87 MPa conditions in this work. The results indicated as follows. First, the most significant effect on autoignition temperature was the presence of branches in the hydroxyl group, followed by the number of carbon atoms, and then the methyl position in the carbon chain. Second, the combustion duration of branched chain alcohols was more sensitive to the equivalence ratio compared with that of straight chain alcohols. Third, methanol and 2-butanol had better combustion effects for stoichiometric combustion than thin combustion, while ethanol and isobutanol were more suitable for thin combustion. Finally, the total particle mass emissions and particle number concentration of all fuels were relatively low at phi = 0.6.