Factors Affecting Theoretical Plate Requirement in Fractional Distillation

University:
The Pennsylvania State University
Course:
CHEM 450 | Thermodynamics
Academic year:

2024
Views:

277

Pages:

1
Author:

Alexis H.

Problem Set #38 Assigned: April 5, 2024 Due: April 8, 2024 at 2:30 pm 1. What factors determine the number of theoretical plates required to achieve a desired degree of separation in a fractional distillation? Note: you need to consider a temperature vs. mole fraction, zA, phase diagram. 2. Consider the liquid gas phase diagram shown below for a mixture of A and B: p PB liquid Zb gas B YB (a) (b) (c) (d) (e) Label the regions which represent the liquid and gas phases. Add labels for PA* and PB* Which liquid is more volatile, A or B? Draw an isopleth going through the green point in the diagram. On the diagram, designate the mole fraction of B in the liquid phase xB and the mole fraction of B in the gas phase, yB at the pressure and zb value denoted by the green point. (f) Using the lever rule, estimate whether the number of moles of B is greater in the gas phase or in the liquid phase at the green point. 1. The principal factor is the shape of the two phase liquid-vapor region in the phase diagram, the closer the liquid and vapor lines are to each other, the more theoretical plates is needed