Measurements of critical properties of ethyl propionate with the gasoline components

Ethyl propionate is a good choice as additive to improve the combustion performance of gasoline. In this work, the critical temperature (T_c) and critical temperature (p_c) of five binary systems (ethyl propionate + n-hexane, ethyl propionate + n-heptane, ethyl propionate + n-octane, ethyl propionate + n-propanol, ethyl propionate + n-butanol) and one ternary system (ethyl propionate + n-hexane + n-propanol) were measured. The results show that the addition of ethyl propionate increases the T_c of n-hexane, n-propanol and n-heptane while decreases the T_c of n-octane and n-butanol. The binary system of ethyl propionate and n-heptane and the ternary system of ethyl propionate + n-hexane + n-propanol are positive azeotropes. The p_c of all studied systems changes linearly with the concentration of ethyl propionate. The applicability of Redlich–Kister equations, Cibulka equations and Singh-Sharma equations were checked.