Assignment: Ion Exchange Pilot Plant SOP
Oregon State University, Gleeson.
Note: This SOP is just a guide. More work can and should be done during the lab periods.
MATERIALS
Equipment (for all three lab periods)
- Safety glasses
- Labeling material (tape and marker)
- Plastic syringe
- Mass balance
- 2 Gal plastic bucket (2)
- Test tube rack
- Test tubes
- pH paper
- Calcium test kit
- 1 L poly graduated beaker
- 50 mL poly graduated cylinder
- 250 mL poly graduated cylinder
- Squirt bottle for rinsing
- PVC stir rod - Ion exchange apparatus with panel, pump, rotometer, and column
- Pre-cut tubing
- Teflon tape
- Ruler
- Funnel
- Watch or timer
Chemicals
- Potable water
- Hydrochloric acid
- Calcium carbonate
- Sodium chloride
Lab Period 1: Standard curve and system volume
Standard Curve Preparation
1. All solution preparation will take place in GLSN 003, and the HCl must not leave the fume hood. Determine the weight of CaCO3 required to prepare 7-8 L of a 640 ppm (mass) Ca2+ solution in your plastic bucket. Identify one team member to do the solution preparation in GLS 003.
a. Add water to bucket while waiting to use the fume hood.
b. First, add about 25 mL of 37 percent HCl to drop the pH below 2.0. Measure and add required CaCO3. This concentration (640 ppm) is an order of magnitude higher than very hard water. This allows a reasonable experiment duration. Be sure the CaCO3 is completely dissolved by stirring and checking for cloudiness. Add more acid if necessary.
Note: This is usually where students make errors that result in several hours of extra work.
2. Prepare and label five dilutions to develop a standard curve for calcium concentrations between zero and 640 ppm Ca2+. Run replicates to enable error analysis.
3. You have been provided with calcium test kit. For each test:
a. Shake Bottle 1, and add 10 drops to each test tube.
b. Shake Bottle 2.
c. Add a drop from Bottle 2 and shake the tube. If the color is blue, stop. If the color is pink, add another drop and shake. Continue until a blue color is achieved.
d. Record the number of drops to turn each test tube solution blue. Make the estimate in standard deviation from your replicates.
4. Create a standard curve by plotting ppm versus drops from Bottle 2. The points should lie in a straight line. If they do not, repeat the analysis.
5. Cover your 640 ppm Ca2+ solution with the bucket label the 6 L of 640 ppm Ca2+ solution for the next lab period.
6. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.
The following is required of your team before you leave the laboratory:
1. Inspect the ion exchange laboratory column. Draw a schematic of the system to scale, from the source/pump to the waste stream.
2. Unscrew and inspect the top and bottom fittings to open the column. Note the screens in the top and bottom fittings to retain the resin.
3. Estimate system component volumes to enable estimation of retention times.
4. Use the resin properties provided by the manufacturer to select 15 sample times you will use to measure exchange capacity during Lab Period 2. The specific times can be adjusted as your experiment progresses. What do you expect to see?
5. Discuss column operating procedure with an Instructor prior to leaving. It is important to minimize air in the system during resin characterization. It may be useful to practice running the column without resin and develop a procedure to avoid entrapping air.
Review these items with an Instructor.
Lab Period 2: Resin characterization
Preparation
1. Measure out 30 mL of ion exchange resin in a graduated cylinder and transfer to a 1 L beaker.
2. Pour potable water into the beaker to cover the resin. Gently agitate for a few minutes to rinse the resin. Pour off the water and replace with new water.
3. Remove exchange column from setup by disconnecting the tubing and releasing the clamp.
4. Transfer the resin into the column. Make sure you use Teflon tape on the threaded seals (ask the TA if unsure). DO NOT OVERTIGHTEN THE FITTINGS.
5. Connect the column and tubing so the direction of flow is up through the column. Push the tubing on only as far as necessary to ensure it is easily removable for later steps. Before reconnecting the top tube, fill the column and tubing with water (as best as possible).
6. Turn on pump, bypass the flow meter, and let water flow for a couple of minutes. (Make sure to eliminate as much air as possible.) Resin will rise in the column. Stop the pump and allow the resin to settle in the column.
7. Turn on the pump, bypass the flow meter, and run 1 L of potable water (without calcium) down through the column. Consider how your flowrate might be verified and also that entrained air and bubbles can affect pumping capability.
Resin Capacity Characterization
1. You are limited to 15 samples, so do a final review of these times with an Instructor. The specific times can be adjusted as your experiment progresses.
2. Stir CaCO3 solution to eliminate gas bubbles that may have formed.
3. Note the time and start your resin characterization process. Pump the 640 ppm Ca2+ solution at 100 ml/min through the column. Execute your sampling and test plan and continue until you have pumped out as much solution as possible. Check your rotometer frequently to ensure constant flow and also check your pump to make sure it stays submerged.
4. Remove the calcium-loaded resin from the column. Store the resin in your labeled bucket covered with any remaining 640 ppm Ca2+ solution.
5. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.
Before you leave the laboratory review the following with an Instructor:
1. Plot the calcium (Ca2+) concentration against time.
2. Estimate the total calcium (mg Ca2+) removed from the water.
3. Do you feel your surface flow rate was appropriate?
4. Knowing the volume of the resin bed, calculate the exchange capacity of the resin as eq/L of resin volume. Compare this result with information given by the manufacturer, and consider reasons for any difference.
Lab period 3: Regeneration of ion exchange resin
Regeneration
1. Separate the calcium-loaded resin from Lab Period 2 from the 640 ppm Ca2+ solution and transfer it into the column. Remove as much of the 640 ppm Ca2+ solution as possible. Plumb the system for downflow.
2. Rinse your bucket, re-label it, and prepare 6 L of 6000 ppm (mass) salt (NaCl) solution. Decide as a team on the pH level you will use and share that with an Instructor.
3. Limit yourselves to 12 samples and decide on a sampling and testing scheme. Your initial sample(s) may have high concentration, so you should dilute it before testing.
4. Carry out regeneration at 150 ml/min until your salt solution is exhausted (consider this a practical regeneration limit). Collect all of the solution that passes through the bed, record the volume collected, and measure the final concentration.
5. If you feel that you have not yet removed enough calcium, consider recycling your solution through again and again monitoring the effluent.
6. Clean up the lab area. All lab stations must be cleaned up before 15 minutes to the hour.
Before you leave the laboratory review the following with an Instructor:
1. Plot the calcium (Ca2+) concentration against time, assess the total amount of calcium removed from the resin, and estimate the regeneration efficiency.
Be sure to calibrate your rotameter at the beginning and throughout your work to ensure confidence in the reading.
Steam Utilization Report Outline
Example 2
I. Abstract
A. Recover energy from a pulp mill steam purge using an available heat exchanger
B. High-level methods
1. Double-pipe heat exchanger run in counter and co-current configurations atflow rates between 6 and 22 GPH
2. Thermocouples used to measure temperature at each inlet and outlet
C. Report on deliverables
1. Report on efficiency of prototype system with evidence (describe how this was assessed)
2. Report on scaled-up design configuration, dimensions [L m] and [d m], andflow rate [F GPH]
3. Estimate annual savings of[$S/yr] and state recommendation WRT implementation
II. Background
A. System characteristics and operating conditions
1. 40 lb/hr steam at 1 atm ~100 degrees C
B. Basics of heat exchanger calculations
1. Sensible heat + latent heat
2. Define equation and the variables mass flow rate, heat capacity at constant pressure, and difference in temperature
3. Efficiency = heat to steam/heat from water
C. Discuss overall heat exchanger coefficient
1. Define equation and the variables including surface area and log mean temperature
III. Materials and Methods(cite SOP in this section)
A. Apparatus for heat exchanger
1. Used prototype double-pipe heat exchanger configured for counter-current and co-current flow
i. Show schematic of apparatus(e.g., pressure cooker, pressure gauge, heat exchanger, rotameter, condensate trap, condensate, cold water source, locations of thermocouples) with all components labeled and concise descriptive caption
ii. Describe in text and refer to schematic
2. Used flow rates of 6, 12, and 22 GPH for each configuration
3. Measured inlet and outlet temperatures every two min over 10 min andcalculated a representative average value
4. Measured condensate volume produced over a period of 10 min to estimate steam mass flow rate
B. Calibration of rotameter
1. Checked the flow rates at rotameter settings of 6, 12 and 22 GPH by measuring the volume of water collected over a period of 10 min
2. Ran three replicates
IV. Results and Discussion
A. Prototype capability compared to existing preheaters
1. Cite preheater specs, compare to efficiency (heat gained by water/heat lost by steam)
2. Report on heat transfer rate as a function of flow rate and configuration
i. Graph of water flow rate (GPH) vs. heat transfer rate (kW)for both water and steam for each configuration (show average of three replicates with error bars representing 90% confidence intervals)
ii. Observed trend with flow rate for each configuration
3. Report on efficiency as a function of flow rate and configuration
i. Discussion of % efficiency as heat transfer rate of the water divided by the heat transfer rate of the steam (X100)
ii. Graph of water flow rate (GPH) vs. efficiency (%) (show average of three replicates with error bars representing 90% confidence intervals)
iii. Counter-current flow is more efficient than co-current flow
B. Consideration of error
1. Rotameter error was significant, estimated to be 0.5 GPH
2. Other error due to lack of insulation on the tubing would be smaller than this
3. Explain effects of error on deliverables
4. Overall heat transfer coefficients
i. Higher for counter-current flow vs. co-current flow, so former preferred
ii. Ballpark comparison of values to literature on published system (cite source)
C. Scaled-up design
1. Strategy to calculate a scale-up factor based on the ratio of the project specified steam mass flow rate of 40 lb/hr and the steam mass flow rate in the prototype
2. Use this to calculate a scaled-up area [A m2], choose reasonable diameter [d m], and calculate required length [L m]
3. Consider safety factor of 1.5X and state assumptions, including constant heat exchanger coefficient and log mean temperature difference
4. Scaled-up system flow rate of [F GPH]
D. Conclusions and Recommendations
1. Estimate of net annual savings
i. Estimate heat transfer rate for scaled-up system [R kW]
ii. Assume $0.07/kW·hr
iii. Report [$S/yr] of net savings and criteria for recommending scaling up
2. Recommend/do not recommend installing heat exchangers
V. Acknowledgements
A. Jane Doe and John Smith for their assistance in collecting and analyzing the data
B. Shujie Li for useful discussions
C. Corey Downs for feedback on technical report writing
VI. Appendices
A. Sample calculations
1. Heat transfer rate for water
2. Heat transfer rate for steam
3. Overall heat transfer coefficient
4. Scaled-up system calculations
5. Estimate of savings per year
B. Tabulated raw dataincluding for rotameter calibration
C. Supporting figures
a. Comparisons of system configurations
b. Error analysis estimates and calcs.
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Section
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Key Questions
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Abstract
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What's the purpose of this project?
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Background
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What information do readers need to understand your methods, findings and recommendations?
What are the science basics?
What's the importance of this project to the broader company goals?
What are the most important equations and physical phenomena that you are working with?
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Materials and
Methods
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What did you do?
Why did you do it that way?
What errors, assumptions, risks or challenges exist because of how you did it?
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Results and
Discussion
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After all the work you did on this project, what can you conclude?
What does the data you collected mean?
Are you reporting on everything you were asked to do?
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Acknowledge-
ments
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Who worked on this project?
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Appendices
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Is there any information some readers might want but is excess detail for the main report?
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