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 balancesfor 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 ’s for the reboiler and condenser.

Figures 1to 4. Include McCabe-Thiele diagrams for each run showing the experimentally-determined stage conditions along with operating and "" 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.

  1. 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?
  2. Determine reasonable estimates for the heat losses to the surroundings. Discuss any implications.
  3. Discuss probable errors in the tray efficiency determinations, distinguishing between systematic and random errors.
  1. 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?
  1. 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).

  1. Tables presenting the following:
  1. The experimentally determined compositions and the calculated Murphree vapor efficiencies for the trays for each run.
  1. A summary of the calculation results obtained from your RADFRACmodel 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.
  1. Sample Calculations

For one total reflux run and for one finite reflux ratio run, show the following calculations in detail:

  1. Material balance (EtOH, H2O, and total) over the column (for the finite reflux ratio case).
  1. Energy balances over the condenser, reboiler, and column.
  1. Vapor and liquid molar flowrates in the column.
  1. Tray Murphree vapor efficiencies from liquid sample analyses. Tabulate efficiencies along with tray number and mole fraction EtOH in the liquid.
  1. Calculation of and overall heat transfer coefficients for the reboiler and condenser.

For each run determine predictions of for your run from the published correlation(s).

  1. Miscellaneous graphs or figures

McCabe-Thiele plots constructed to determine numbers of ideal stages.

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.

Calibration curves and any other diagrams developed by you and used in your report but not specifically discussed elsewhere. (Don’t include copies of diagrams that are given in this manual.)

  1. DO NOT include original data. If needed, it will be requested.

Additional points are reserved for professionalism in the laboratory and the general appearance of your laboratory report.