This note is an extension of my previous note "Separating Oil from Water by Freezing the Water" that could be found here.
In general I am attempting to separate oil and water by freezing. This research note is a new addition to that. In particular I was testing two things: 1. How much oil can I recover from water each time if I re-freeze the oil/water (OW) mixture repeatedly? 2. Does the repetition of this process changes the oil spectra?
Initially I was thinking to repeat the freeze / defrost / collect cycle as many times as possible, but as it turned out only one extra cycle produced enough recovered product oil to collect without using a cotton swab method (this collection method requires mixing the spec with mineral oil. I am trying to avoid mineral oil, since it slightly changes the measured spectra).
I was able to recover various amounts for different kinds of oils. I assume this is mainly due to two factors: viscosity, and the amount already recovered before this particular collection cycle. For example the 5W30 oil is quite viscose and if cold, doesn't collects well (doesn't flow or drips well). This particular oil also changes color from transparent honey to milky white. More info on that in separate note here. On the other hand the much lower ConEd Dielectric Fluid was not possible to recover because I recovered most of the of the product in the first collection cycle before.
Here are the amounts of oils per oil/water mixture (OW ratio 1:20) I was able to recover in the second cycle:
5W30: 4 drops Crude North Dakota: 6 drops ConEd Dielectric Fluid: 0 drops 20W50: 6 drops 80W90: 5 drops
One very important note on how NOT to drip melted ice water into your sample: Leave your frozen sample in the fridge at all time. Take it out only when collecting the sample. Do not hold the frozen sample with your bare hand, because it will start melting very quick. Even if you are not holding the sample with a bare hand, water will start melting approximately in 1 minute in a room temperature. That said, you have to collect all the oil you can within 1 min.
here are some measured spectra that Spectral workbench produced a match: Crude recovered Cycle 1:
Crude recovered Cycle 2:
Crude Oils Compared:
80W90 recovered: Did not matched spectra from the 1st cycle.
Next steps will be to better compare the measured spectra and update the note.
I am interested to test figure out a way how to prepare best specs for the OTK and to test the ability of different different DIY techniques to separate oil from water. This is one of the methods I am trying.
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oil fluorescence crude sampling
Here is a screenshot of three scans of diesel oil, set https://spectralworkbench.org/sets/2877 :
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spectrometer oil-testing-kit oil-testing-kit-beta
Run through the Oil Testing Kit Beta program so I can better articulate what someone might need to do to run this as a workshop. Did this test with members of the Gulf Coast Chapter!
Initially I had difficulty getting my oil cuvette holder to line up with the laser. I took a que from @Cindy_ExCites research note on technical adjustments and found that if I raised my holder slightly and angled the laser up just slightly, it lined up much better.
Also, when I got everything lined up correctly, the laser was not lining up where it should be at 405nm, but was instead around 200. So I recalibrated it and tried again. One thing I figured out was that I needed to refresh my scanning page with the new calibration and that seemed to work.
I had put the number stickers on my samples and recorded what they were in my notebook. I mixed up my samples and grabbed one without looking at the number, scanned it, and this is what the scan was::
Based on my other scans, I was able to correctly identify that this one was 80w90.
I'm seeing the value having the steps walk you through taking samples. I found myself searching through all the options on SWB to find the ones that I was supposed to use for the beta program (some are right on the page, the others are hidden among many other options that I found a little confusing. One suggestion I could make would be to have a "bear bones" SWB version that is automatic and only includes the macros one needs to run through a basic scan and comparison test. Also a clippy for beginners.
I found myself wishing that the calibration I selected for my first scan stayed the default for the ones that followed. I had to select the same calibration for all of the scans. --Tags stay the same, can the calibration?
Some things that are not as intuitive or probably will need explaining on a workshop are ::: your scan page stays open, you only save once your sample scan goes the length of the window, your "sample" then opens on a new tab where you can detail info about what it is. You return to your "scan tab" when you're ready to scan your next sample.
Question: I did not change my sample on each scan, just did three scans. Wanted to make sure this was correct.
Next Steps: Keep an eye out for the workshop, coming soon! Also, love some feedback!
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spectrometer oil-testing oil-testing-kit otk
Here is a screenshot of my set of three scans of 80W90, https://spectralworkbench.org/sets/2876 :
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spectrometer oil-testing-kit oil-testing-kit-beta
Here is my screenshot of my set https://spectralworkbench.org/sets/2874, three scans of crude oil using a blue laser.
My experimental setup is a bit odd so i'll attach a photo. i had to angle the spectrometer to get a scan. I also had to cut the slots on the cuvette holder 1/8" lower for two reasons:
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spectrometer oil-testing-kit oil-testing-kit-beta
I wanted to show a different idea for a cuvette frame, with emphasis on simplicity of construction to allow for home-building.
I purposely made this in a huge hurry, using only a paper cutter, tape and a pocket knife. It took about 2 minutes to complete (and it shows!)
A final design would of course be of higher precision, and fit into a box, not just a sleeve. I was trying to make it easy to take apart and fuss.
Here are the total parts I used. It's a larger piece to serve as the body. Would eventually be a full enclosure box. Then there are three squares, two with cuvette-size hole cut out, one solid. There are two strips of paper that are rolled up to fit into the sleeve. One is ~3/8" and the other ~1 1/2", and the length is arbitrary (as they roll up).
this is the "exploded view" trying to show the order these things drop into the housing.
The housing just looks like this:
The angluar piece is just a couple strips stapled together to provide a strong base where the cuvette touches down. I just took one strip of 1 1/2" paper, ripped it and stapled it as shown, then bent to fit in base of the sleeve.
The first frame piece just keeps the base of cuvette from kicking out, so it's only a bit above the base.
Well, it's just a quick mockup. Would need hole through the housing and the lifter strip in order to allow light to come from the fluoresced cuvette, and to get from the light source to the sample. This could be done simply, by just cutting out from the strip, or be reimagining that main strip to be some other form of support for the top cuvette holder, with that in mind.
After hearing feedback from a beta OTK user that it took them 3+ hours to fold the kit, we started jotting down ideas on how to drastically simplify the construction. Also in order to allow more people to participate in research in this direction, without needing a kit from us. Design goal was "what is the quickest way I can get a light-tight cuvette frame, with no special tools?"
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spectrometer desktop-spectrometer cuvette oil-testing-kit