Unit Operations Laboratory -Continuous Distillation 
Dr. Russell Chen

Objectives - Prelab - Hints

Objectives

Guidelines for Experimental Objectives

    Using the continuous distillation column, produce a distillate of at least 90 wt%  methanol from a feed of 30 wt% methanol in water.  The column contains 12 real trays, a total condenser, a reboiler, and four possible feed locations.
Specify the experimental conditions, carry out experiment and plot the trend for five variables.

Design Objective

     You are also asked to use the information obtained in the lab to design a continuous column using similar trays to produce a methanol 90 mole% and a water 99 mole% from a feed of 50 wt% methanol at a flow rate of 1000 cc/m.   Please specify the number of stages, reflux ratio, feed stage and feed temperature.

Question for prelab meeting:

     Can you use the McCabe-Thiele method for the analysis and why?
     What is the theoretical minimum number of ideal stages required to achieve this separation?
     Where is the optimal feed stage using minimum number of ideal stages?
     How do you estimate the stage (Murphree) efficiency and column (overall) efficiency?
 

Prelab Guidelines

These are in addition to the standard guidelines.

Experimental Methods: Specify the the data required to calculate the stage efficiency and which stage(s) data can be obtained.
           Specify the data required to calculate the column efficiency.  Obtain at least 4 estimates on efficiency and show them
           in your data table.

Expected Data: Estimate the compositions at total reflux and at the specified operating conditions assuming 100% efficiency.
 

Hints
(1) McCabe-Thiele, Murphree, subcooled, total condenser, equimolar overflow, mass and energy balances.

  • Send mail to Dr. Chen: wchen@bobcat.ent.ohiou.edu.

  •  

     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     

    (Last modified on 1/2/01)