CBN Smells Like Eggs

Hey there!

We received a sample of a high CBN distillate today, but it smells terrible, like rotten eggs - like sulfur dioxide. My guess is that this was made via the iodine induced aromatization method that has been shared here and the sulfur is coming from the iodine removal process. Possibly residual HCl and sodium thiosulfate solution making sulfur dioxide? @anon93688 I know you have been working on this. Also @QGA if you have any ideas too.

Does anyone know what this could be and have you experienced something similar with high CBN products?

Thanks!

Edit: here is a photo of it. Color looks pretty good…

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I can confirm that.

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Confirm that it is a sulfur dioxide byproduct?

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It’s sulfur dioxide. People are having trouble purifying it when running the iodine oxidation.

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Makes sense, thanks guys!

Does anyone have a PDF of this paper btw? https://pubs.acs.org/doi/pdf/10.1021/acs.jnatprod.7b00946

I don’t have ACS access anymore and I have only sent he link shared on here :frowning:

Yes. It is.

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try refluxing in solution with some freshly shaved pure copper?

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I tried to post an interesting paper but cant find the original link.

“The chemistry of copper-containing sulfur adsorbents in
the presence of mercaptans”

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I sent you a DM and thanks for all your posts! :smiley:

Do you mean the actual paper?

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Yes thats the one, i have it downloaded but couldnt find an open source link.

That’s not an open source link. I didn’t find one that was, except for Sci-Hub of course :slight_smile: (if you get the 504 Bad Gateway error just refresh until you get the PDF)

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Man, i have so many papers, studies and instructions saved and downloaded, i never remember where they came from originally. I keep using the term ‘‘papers’’ and it feels wrong.

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You’re good, honestly university faculty will often send you research paper PDFs for free because they’re getting less than musicians for royalty every time their paper is viewed. The money goes to the subscriptions.

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Plus. The people publishing the papers almost always have the right to distribute them. They’d probably be stoked knowing people are reading their stuff. Plus they’d likely be able to strike up a good conversation on some of the finer points of their research.

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Me too, I’ve got like 3 GB in pdf files related to this kind of thing. Sometimes it feels like all I do in my spare time is read.

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idk if this is ok to mention or not here, but sci-hub.tw is great for getting around paywalls

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Regarding SO2 removal…looks like various alkali would do the trick. These processes are used industrially to sequester SO2 from emissions, however a gas phase is being filtered as opposed to liquid/solid. Seems like you could do an aqueous wash with Mg(OH)2, producing MgSO3 as a biproduct which is water soluble. Other weak bases might work well as they create OH- ions in solution. NaOH is probably not going to work well as it’s more reactive and will probably oxidize your product. I haven’t tried any of these out yet so maybe someone who has can chime in.

CaCO3(s) + SO2(g) → CaSO3(s) + CO2(g)

When wet scrubbing with a Ca(OH)2 slurry, the reaction also produces CaSO3 and may be expressed in the simplified dry form as:
Ca(OH)2(s) + SO2(g) → CaSO3(s) + H2O(l)

When wet scrubbing with a Mg(OH)2 slurry, the reaction produces MgSO3 and may be expressed in the simplified dry form as:
Mg(OH)2(s) + SO2(g) → MgSO3(s) + H2O(l)

To partially offset the cost of the FGD installation, some designs, particularly dry sorbent injection systems, further oxidize the CaSO3 (calcium sulfite) to produce marketable CaSO4-2H2O (gypsum) that can be of high enough quality to use in wallboard and other products. The process by which this synthetic gypsum is created is also known as forced oxidation:

CaSO3(aq) + 2H2O(l) + ½O2(g) → CaSO4 · 2H2O(s)

A natural alkaline usable to absorb SO2 is seawater. The SO2 is absorbed in the water, and when oxygen is added reacts to form sulfate ions SO4- and free H+. The surplus of H+ is offset by the carbonates in seawater pushing the carbonate equilibrium to release CO2 gas:

SO2(g) + H2O(l) + ½O2(g) → SO42−(aq) + 2H+

HCO3− + H+ → H2O(l) + CO2(g)

In industry NaOH is often used to scrub SO2, producing [sodium sulfite]
2NaOH(aq) + SO2(g) → Na2SO3(aq) + H2O(l)

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