Propane-propylene separation efficiency

In this chapter, we examine the thermodynamic efficiency of the propane-propylene separation process by distillation. The tools necessary for this analysis are developed using the first and second laws of thermodynamics. Sources of thermodynamic inefficiency are pinpointed and, finally, some options are discussed to improve the efficiency of the separation. 

A separation of propylene from propane is achieved by distillation as shown below, where two columns in series are used because a single column would be too tall. The tray numbers refer to equilibrium stages. Determine the column diameters, tray efficiency, number of actual trays, and column heights if perforated trays are used. 

For a detailed analysis of the reboiler-flashing configuration, which is usually the most financially attractive of the three configurations, the reader is referred to Example 9.4, in which the lost work and thermodynamic efficiency are computed for the separation of propylene and propane. Note that these configurations are most attractive for the separation of... 

Estimate the exergy efficiency of the distillation column for propylene—propane mixture, which is a close-boiling mixture. The table below shows the enthalpy and entropies of the saturated feed and saturated products from the simulation results with the Redlich—Soave equation of state for the separation of propylene and propane (Seider et al. (2004). 

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