A pilot scale distillation column was used to separate a 10 – 20 weight percent aqueous solution of ethanol. Ice was used to cooldown the samples that would be later analyzed with a refractometer which was calibrated with tap water. The main piece of equipment was a twelve-tray bubble-cap distillation column with condenser and thermo-syphon reboiler. The whole experimental setup was controlled via computer control system which allowed observation of liquid levels, temperature, and pressure in different sections of the distillation column.
An important part of the experiment was data collection and recording which was performed using a refractometer. A micropipette with one milliliter tip was used to take more than 50 samples which were stored …show more content…
One major concern was the release of ethanol vapor into the lab environment. To prevent this, a sensor had been installed at the top of column which would set off an alarm if the top exceeded a set temperature. One team member was sent to the third level to watch the column trays and overhead condenser to ensure tray flooding did not occur.
One indicator that the column was approaching steady-state was consistent temperature values for the bottoms and all twelve trays. After 30 minutes had passed, the first samples from the distillate and bottoms were taken. An additional three samples were taken at ten minutes intervals from this point. If weight percent values were within 1% of the previous sample, the system was assumed to be at steady-state. If the samples continued to vary, the system was allowed more time to equilibrate and further samples were taken.
The next step was to take samples from the bottoms, distillate, feed, and twelve trays at steady-state. In addition to samples, the reflux ratio, reflux flow rate, overhead product flow rate, temperature profile, and pressure drop were recorded. The inline graduated cylinder and a stopwatch were used to measure the overhead product flow rate. After all samples had been collected, the feed tray location was changed and the column allowed to reach steady state once …show more content…
Failure to re-open the return line and close the sample valve could result in overflow of the graduated cylinder and improper functioning of the column. Steady state may be altered by failing to correct the valve positions as well.
Tray flooding may occur during the experiment causing column pressure buildup. Ensure one student is constantly monitoring the column during operation to watch for any excessive flooding on the trays.

As for chemical hazards, ethanol is highly flammable liquid and vapor. Single spark could start fire, therefore, use of any open flame and electrical equipment should be avoided near ethanol. To prevent eye and skin exposure, safety goggles and nitrile gloves had to be worn. The following PPE equipment was required throughout the duration of the experiment: a hard hat, safety goggles or glasses with side shields, appropriate clothing which covers arms and legs, closed-toe shoes, thermal gloves for operating steam valves, and purple nitrile gloves for handling ethanol/water solutions. In case of fire or fire, the team would have to shut down the distillation column and