oa Boiling Of Binary Hydrocarbon Mixtures On Water

The boiling of binary hydrocarbon mixture on water exhibits a special immiscible liquid-liquid heat transfer phenomenon where the heat transfer parameters change rapidly in a short duration of time. The boiling of hydrocarbon mixtures involves a process called ageing where the vaporization of most volatile component takes place faster leaving behind the less volatile component. This process establishes a concentration gradient which changes with time. The boiling heat flux thus produced for mixtures is quite different from this of the pure component. In the boiling of a pure liquid the entire boiling process is heat transfer controlled. In contrast, when a multicomponent mixture boils, the vapor and liquid phases are present in different composition and boiling process is controlled by both temperature and concentration gradients. The boiling of two different binary mixtures of hydrocarbons comprising of methane-ethane and methane-propane was studied. Theoretical correlations for nucleate and film boiling, which takes into account the modified heat transfer coefficient and wall superheat heat, were used to determine the heat flux. The modified heat transfer coefficient called ideal heat transfer coefficient was found to be a function of the concentration of the light components. The ageing of the mixture was expressed as a ratio of heavier to the lighter hydrocarbons. Predicted heat flux values were compared against experimental data and showed moderate-good fitting with the model with some identified trends.