Gasoline cloud point

The tendency to separate is expressed most often by the cloud point, the temperature at which the fuei-alcohol mixture loses its clarity, the first symptom of insolubility. Figure 5.17 gives an example of how the cloud-point temperature changes with the water content for different mixtures of gasoline and methanol. It appears that for a total water content of 500 ppm, that which can be easily observed considering the hydroscopic character of methanol, instability arrives when the temperature approaches 0°C. This situation is unacceptable and is the reason that incorporating methanol in a fuel implies that it be accompanied by a cosolvent. One of the most effective in this domain is tertiary butyl alcohol, TBA. Thus a mixture of 3% methanol and 2% TBA has been used for several years in Germany without noticeable incident. 

While such data are not included in this report, our work has also shown that in FCC operations the acidic matrix is able to better crack and isomerize more n-paraffins, thus reducing the n-paraffin content in middle distillate and thereby the characteristic high cloud point associated with it, while also raising octane number by removing or isomerizing n-paraffins in the gasoline fraction. 

Commercial value of a petroleum liquid can be estimated quickly through measurement of the following physical characteristics . specific gravity, gasoline and kerosene content, sulfur content, asphalt content, pour point, and cloud point. 

Catalytic hydrocracking is a modern refinery tool to produce clean fuels (Gasoline and Diesel). The versatility of this process is due to the catalyst formulation. When Diesel fraction quality is targeted, catalyst must produce a highly isomerized product to increase the cetane number, but still having a good cloud point. 

Isomerization reactions (reaction class 2) give an important pathway for high-octane components in the gasoline. This class of reactions is critical for producing high-octane components in the gasoline products. In addition, we find more valuable iso-butene components due to the isomerization of butanes. The isoparaffins from the isomerization class of reactions also reduce the cloud point of the diesel product [1]. 

---