Separating Processes

Holland, C. D., "Fundamentals and Modeling of Separation Processes," Prentice-Hall, Englewood Cliffs, N.J. (1975). 

Flotation. Flotation is a gravity separation process which exploits differences in the surface properties of particles. Gas bubbles are generated in a liquid and become attached to solid particles or immiscible liquid droplets, causing the particles or droplets to rise to the surface. This is used to separate mixtures of solid-solid particles and liquid-liquid mixtures of finely divided immiscible droplets. It is an important technique in mineral processing, where it is used to separate different types of ore. 

King, C. J., Separation Processes, 2d ed., McGraw-Hill, New York, 1980. 

Rousseau, R. W., Handbook of Separation Process Technology, Wiley, New York, 1987. 

Reverse osmosis is a high-pressure membrane separation process (20 to 100 bar) which can be used to reject dissolved inorganic salt or heavy metals. The concentrated waste material produced by membrane process should be recycled if possible but might require further treatment or disposal. 

Rectification is of the greatest industrial importance in particular, it is the principal separation process employed in the petroleum industry. 

Separation Processes that split a feed into simpier or narrower fractions. 

The foremost separation process is crude distillation and in second place, if deeper conversion is envisaged, solvent extraction (deasphalting). 

Among the other separation processes, one can cite the following ... 

These constants are dependent upon pressure, temperature and also the composition of the hydrocarbon fluid, as the various components within the system will interact with each other. K values can be found in gas engineering data books. The basic separation process is similar for oil and gas production, though the relative amounts of each phase differ. 

Multi-stage separation may also be constrained by low wellhead pressures. The separation process involves a pressure drop, therefore the lower the wellhead pressure the less scope there is for separation. 

In both cases the late stages of kinetics show power law domain growth, the nature of which does not depend on the mitial state it depends on the nature of the fluctuating variable(s) which is (are) driving the phase separation process. Such a fluctuating variable is called the order parameter for a binary mixture, tlie order parameter o(r,0 is tlie relative concentration of one of the two species and its fluctuation around the mean value is 5e(/,t) = c(r,t) - c. In the disordered phase, the system s concentration is homogeneous and the order... 

Therefore, the locus of the values ( ) with a vanishing second derivative of A delimits the region of the miscibility gap in which spinodal decomposition occurs. This locus is referred to as the spinodal (figure C2.1.10 (bl). The length scale of the concentration fluctuations at the beginning of the separation process is controlled by... 

To circumvent this need for calibration as well as to better understand the separation process itself, considerable effort has been directed toward developing the theoretical basis for the separation of molecules in terms of their size. Although partially successful, there are enough complications in the theoretical approach that calibration is still the safest procedure. If a calibration plot such as Fig. 9.14 is available and a detector output indicates a polymer emerging from the column at a particular value of Vj, then the molecular weight of that polymer is readily determined from the calibration, as indicated in Fig. 9.14. 

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