Distillation Experiment
REPORT ITEMS for FULL REPORT
NOTE:
Preferably only use either accepted SI units, but if you decide to give use English
units do not use nonstandard English units. Report mass balances in mol/s and energy
balances in kW.
i)
Abstract. (Do not include an introduction).
ii) Summary of Results. Start this section with a single paragraph in which each of the following
tables and figures is presented. Do not discuss anything yet.
Table 1. (Finite reflux ratio runs) Show the unreconciled (raw) mass balance numbers
and the associated closure error. Use the standard format for a mass balance table,
showing species molar flowrates and totals [in mol/s].
Table 2. Show a reconciled steady state material balance for both runs [in mol/s].
Table 3. Energy balances for all the runs showing heat duties for the reboiler and
condenser, heat flows associated to the process streams (only for partial reflux
runs) and heat losses.
[Inputs: QR and F HF; Outputs: QC, D HD, B HB, and heat losses; in kW].
Table 4. Overall heat transfer coefficients and Tmean ’s for the reboiler and condenser.
Figures 1 to 4. Include McCabe-Thiele diagrams for each run showing the
experimentally-determined stage conditions ( y n , x n ) along with operating and
" q " lines as appropriate. Show the corresponding results for the Java applet
and/or the Aspen RADFRAC model on the same diagram for comparison.
Regarding the actual data points, draw them by hand on top of the corresponding figure
and label them with actual stage number.
Table 5. Liquid compositions, vapor compositions (calculated from the experimental
liquid compositions) and the calculated Murphree vapor efficiencies for the trays
associate with the active region for each run.
Table 6. Comparisons of the number of actual stages with the numbers of theoretical
stages determined by the McCabe-Thiele method. (At finite reflux ratio, report
stage counts above and below the feed separately.)
Table 7. Overall heat transfer coefficient for all runs (give SI units).
iii) Discussion. Write one paragraph for each of the following discussion items in the given order.
a.
b.
c.
Discuss the probable accuracy of the material and energy balances, and possible reasons for any
major errors. How did you arrive at the reconciled balances?
Determine reasonable estimates for the heat losses to the surroundings. Discuss any
implications.
Discuss probable errors in the tray efficiency determinations, distinguishing between
systematic and random errors.
Distillation Experiment, p. D-2
d.
What do your data show about the tray efficiencies? Compare with efficiency data in the
literature, e.g. pp. 14-34—14-38 in Perry's Chemical Engineer's Handbook, 7th Ed.
How might differences in tray design or operating conditions explain any differences
with reported values? Is the diameter of the column adequate for those operating
conditions?
e.
Discuss the heat transfer coefficients obtained. Compare to expected/literature values.
Are the observed values reasonable, and do the differences observed between runs make
sense? Why or why not?
vii) Appendices (Hand written with pencil or ink is acceptable, but it is still part of the report so it must
be neat).
a.
Tables presenting the following:
1.
The experimentally determined compositions and the calculated Murphree vapor
efficiencies for the trays for each run.
2.
A summary of the calculation results obtained from your RADFRAC model of each run.
Give this as a single table or spreadsheet printout, showing the following for each calculation case: feed
and product material balances (molar flowrates of EtOH and H2O), reboiler and condenser duties, reflux
ratio, numbers of rectification and stripping stages, and the tray efficiencies values used in the model.
b.
Sample Calculations
For one total reflux run and for one finite reflux ratio run, show the following calculations in detail:
1.
ratio case).
Material balance (EtOH, H2O, and total) over the column (for the finite reflux
2.
Energy balances over the condenser, reboiler, and column.
3.
Vapor and liquid molar flowrates in the column.
4.
Tray Murphree vapor efficiencies from liquid sample analyses. Tabulate
efficiencies along with tray number and mole fraction EtOH in the liquid.
5.
condenser.
Calculation of Tmean and overall heat transfer coefficients for the reboiler and
For each run determine predictions of E MV for your run from the published correlation(s).
2.
Miscellaneous graphs or figures
McCabe-Thiele plots constructed to determine numbers of ideal stages.
Distillation Experiment
For each run show a plot of tray temperature versus tray number, labeling curves drawn for different
times before and after sampling, to show how constant the operation was during the sampling period.
Also show the tray temperature versus time trend curves running from 30 min before sampling until after
sampling was completed.
ves and any other diagrams developed by you and used in your report but not specifically discussed elsewhere.
copies of diagrams that are given in this manual.)
DO NOT include original data. If needed, it will be requested.
ts are reserved for professionalism in the laboratory and the general appearance of your laboratory report.