Uytengsu Teaching Center Chemical Reactor Standard Operating Procedure

Transcription

1 Uytengsu Teaching Center Chemical Reactor Standard Operating Procedure Prepared by: David Bergsman Date: 3/30/2016 Section 1: Purpose This document describes the proper use and maintenance of the teaching lab Chemical Reactor used for lab demos. Section 2: Application This reactor's primary purpose it to be used to demonstrate the use of the constantly stirred tank reactor (CSTR), the plug flow reactor (PFR), and the batch reactor, common reactor tropes in chemical engineering. The reactor should not be used for any other purpose besides lab demostrations. Section 3: Equipment, Chemicals and Supplies The chemical reactor equipment includes the reactor state itself, two detachable reactors and one tall plug flow reactor, an attachable flow valve for the PFR demo, a permanently attached heating/cooling apparatus, several detachable hoses, several labelled bottles, several generic bottles, several clip-in tube connectors, manuals for the reactor stage and each reactor type, waste jugs, and a computer. Chemicals generally used include sodium hydroxide (NaOH), Ethyl Acetate (EthAce), deionized water (DI), and an Indigo Carmine dye (IC). The demos also use other chemicals, such as Potassium Chloride (KCl), which have not yet been purchased, but can be used according to the lab demonstration booklets. Section 4: Operational Procedures In general, the use of the reactors should follow the procedures outlined in the reactor stage manuals as well as the manuals for each individual reactor. Each reactor manual contains example reactions and proposed experiments. Please consult the manual for general housekeeping instructions. Included below is a list of general procedures and notes for the use of the reactor. 4.1 Startup: To begin using the reactor, plug the reactor into a typical wall outlet using the power cable. Ensure that the breakers are all set correctly, then turn the reactor power on. No visible change should occur. Plug the reactor into the computer using the front panel's USB port. Once plugged in, the USB Power light should turn on. 1

2 Open the reactor software of the reactor that you intend to use (PFR, CSTR, Batch. The software for all reactor types are easily located in Windows start menu (they are pinned)). Select the experiment you intend to perform. If you have no specific experiment in mind, select the experiment that most closely relates to your reaction of interest (see the Reactor manuals). When the software loads, it will display a small Powerpoint presentation of information. To access the controls, select "View" and then "Diagram". This will bring up the control panel for the reactor. To connect the software to the reactor, press the "COM" Start button (looks like a phone). Select the appropriate COM port (COM4 usually) if it asks. The bottom right corner of the screen will then show that the connection has been established, and the "USB Active" light on the front panel of the reactor will be lit. General reactor controls on the control panel are as follows: Pressing the small "Power" button will activate any controls you set. Turning off that power button will immediately stop any pumping, stirring, etc. The WatchDog will ensure that the settings of the panel do not exceed any limits. Changing the pumping rate will speed up the pumps. Maximum speed is around 150 cm 3 /min. Stirring rate is a percentage from 20%-100%, or 0% to stop (anything below 20% won't run). To use the temperature probe, plug in the probe with its extender cable into one of the ports in the back of the reactor. Feed the temperature probe through the appropriate port in the reactor. The Software can now record the temperature. The concentration probe works the same way (see the general reactor manual for more information). There is a low and high concentration port it can be plugged into. Play around with both to see which sensitivity is better for your reaction conditions. To record data, press the "Go" button on the top of the control panel. You can then see the recorded data through various options in the software. Press "Stop" to stop the data collection. The reactor comes with four labeled dark bottles for storing the reactants, which contain approximately 2.5 L each. Before running a demo, it is recommended to fills these bottles separately beforehand, then place them into the large secondary container divot in the middle of the reactor stage. Place the two small rubber hoses through the small holes in the cap and attach these hoses to the left side of the two pumps. Note that as the bottles begin to drain, they may need to be leaned to one side to get all or most of the liquid out. The NaOH solution should always be plugged into the first of the two pumps. The EthAce should always be plugged into the second of the two pumps. Always bring a large jug of DI water when performing any reaction experiment, as described later. For the CSTR reactor, install the reactor onto the four screws in the top of the reactor stage and screw it down. Place the thicker hoses into the two clip-in inlets of the bottom of the reactor and place the other end of these hoses into the pumps. Ensure that the middle black 2

3 drain valve is closed. Place the thickest hose onto the tall metal nozzle on the right side of the reactor and place the other end of the hose into a waste jug. The height of the tall metal tube is what determines the total volume in the CSTR: when the liquid gets to that height, it starts to drain into the waste bin. Plug the stirrer into the back of the reactor stage into its appropriately labelled plug. If heating/cooling is desired, follow the appropriate instructions in the CSTR manual. For the PFR reactor, place the PFR reactor on the floor. Install the small 6-way switch to the reactor stage and plug its outlet hoses to the bottom of the PFR. Attach the inlet hoses to the right side of the pumps. Insert the temperature probe and the concentration sensor into the top of the PFR, then place the outlet of the PFR into a waste jug sitting on the countertop. 4.2 Suggested reaction conditions: For the CSTR, try using 0.1M NaOH and 0.1M EthAce, with 0.1g IC loaded into the NaOH (that way the solution entering the reactor looks yellow before turning blue. Run the system at 50 cm3/min for both flows. For the PFR, try using 0.2M NaOH and 0.5M EthAce, with 0.5g IC loaded into the NaOH. Run the system at 50 cm3/min for both flows. 4.3 Clean-up When finished running an experiment in the CSTR, transfer the two hoses in their respective bottles into the DI Water and continue to pump DI water into the CSTR. Attach a hose to the middle drain and put the other end of the hose into the waste jug as well. Drain the liquid out of the reactor, and refill it with DI water several times. This will also clean out the hoses and pumps. Once finished, remove all the hoses and reactant jugs and rinse thoroughly with DI water. When finished running the PFR experiment, transfer the two hoses in their respective bottles into the DI Water and continue to pump DI water into the PFR. Once it is mostly filled with DI Water, remove the hoses from the pump and drain the liquid into a waste jug. Then remove all the hoses and reactant jugs and rinse thoroughly with DI water. Section 5. Primary Hazards Sodium Hydroxide HEALTH: 3 FLAMMABILITY: 0 REACTIVITY: 1 See MSDS for information. Very hazardous with skin contact, eye contact, ingestion, inhalation. 3

4 Ethyl Acetate HEALTH: 1 FLAMMABILITY: 3 REACTIVITY: 0 See MSDS for more information. Hazardous in case of ingestion. Irritating to skin and eyes. Indigo Carmine HEALTH: 1 FLAMMABILITY: 0 REACTIVITY: 0 See MSDS for more information. Irritating to eyes. Hazardous to ingestion or inhalation. Slightly irritating to skin. There is a chance for equipment falling from the countertop onto someone. Ensure that everything is secured to the counter when not in use with Quakehold Secure Straps. Section 6. Personal Protective Equipment The following equipment should be used when working with these chemicals: Safety glasses. Long pants and closed-toe shoes. Nitrile gloves (replace gloves upon exposure to ethyl acetate, which may permeate the gloves). Lab coat. Section 7. Engineering Controls to Prevent and Mitigate Hazards Ensure DI Water is pumped through lines and hoses after use to prevent possible exposure. Section 8. Special Handling Procedures None Section 9. First Aid and Emergency Procedures Spill: Concentrated NaOH: clean up with spill kit. All other chemicals: wipe up with wet and then dry paper towels and dispose as chemical waste. Exposure: rinse exposed areas with copious amounts of water. Seek medical attention if necessary. Section 10. Training Training to be received only by previous trainer or lab manager. 4

5 Section 11. References MSDS is attached for sodium hydroxide, ethyl acetate, and indigo carmine. 5