In case of immiscible mixture loading, the calculation model uses same method as miscible product loading model.
In this case, and considering that the two mixtures are immiscible, dilution factors are not considered during loading operation (for loaded products or initial mixture in the vessel). Equilibrium vapour composition is thus determined based on the initial composition of each mixture.
For this model it is considered that the temperature of initial products and added products does not change during loading operation. Calculation of vapour pressure for each product is done at the specified temperature.
2 m3 of toluene at 20°C are added in an atmospheric vented vessel above 6 m3 of water at 20°C. The system pressure is 760 mmHg.
The initial and added products weights are as follows:
Partially vapour pressure for the different products are:
Calculated atmospheric emissions are as follows: