乙醇汽油体系的热力学性质

Thermodynamic Properties of Gasohol

用低温绝热量热计测量了国产93#无铅汽油和乙醇混合体系(50 wt%乙醇+50 wt%汽油及90wt%乙醇+10wt%汽油)在78-320 K温区的热容.用最小二乘法拟合了热容与温度的函数关系.由热容随温度的变化曲线可知,E50和E90混合体系分别在95.61 K和97.08 K发生玻璃化转变;在118.03 K和112.04 K发生固—固相变;在156.26 K和158.66 K发生固—液相变.计算了以298.15 K为基准的该混合体系的热力学函数.

The heat capacities （Cp） of two kinds of gasohol composed of 50 wt% ethanol and 50 wt% gasoline 93^# , and 90wt% ethanol and 10 wt% gasoline 93^# are determined by an adiabatic calorimeter. The glass transition temperatures were found to be 95.61 K and 97.08 K, respectively. The liquid-solid transition and solid-liquid transition occurred at 118.03 K, 112.04 K and 156.26 K, 158.66 K, respectively. The relationship of Cp with respective to temperature T is established by using least square method. According to the relationship, the thermodynamic functions of the gasohol are derived.