Effects of isopropanol addition on gasoline-alcohol motor fuel blends

For a successful application of gasoline/alcohol mixtures as motor fuel the realisation of a stable homogeneous liquid phase is one of the major problems. The alcohol component of the mixture is hygroscopic and depending on the environmental temperature and humidity contains a certain amount of water; also gasoline is not always moisture free. Therefore an alcohol-gasoline mixture is a three-component system, the third one being water. Generally, as the environmental temperature decreases the probability of phase separation increases. In this investigation isopropanol is added to various systems of gasoline-methanol-water in order to study the decrease of the phase separation temperature; also the effect of temperature on water tolerances is determined.