April 23, 2025, 12:02:00 PM
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Inorganic Chemistry Forum / Re: Less toxic substitute for Hydrazine?
« Last post by Hunter2 on Today at 12:16:09 AM »
Quote
It can be synthesized from the reaction of hydrazine sulfate and hexamine

Makes no sense. He don't want to use hydrazine ( derivates).
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Chemical Engineering Forum / Re: Mixing Scale-up
« Last post by marquis on Yesterday at 06:08:37 PM »
You never can tell.  Sometimes, the transition from lab scale to pilot to production is seamless with no issues.  On the other hand, there have been many times when the transition from lab scale to pilot scale was.a royal pain in the butt.  Keep your eyes open and look for anything out of the ordinary and you should be ok.  But yes, bad things can happen...
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Chemical Engineering Forum / Re: Mixing Scale-up
« Last post by marquis on Yesterday at 12:42:59 PM »
Don't know if this came through or not. So try again.  First try is a Mixer /
reactor manufacturer.  They can take your reaction and recommend a type of reactor as well as a way to try it.  This will be quite expensive.

Then  there are customs mixers.  They will take your materials, in the pilot scale, and run it for you.  Again, typically, quite expensive.

Good luck with your project!
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Organic Chemistry Forum / Re: A-chlorination carbonyls with H2O2/HCl
« Last post by rolnor on Yesterday at 12:43:47 AM »
It seems natural to try a larger excess H2O2 and HCl? Do it in the cold.
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Organic Chemistry Forum / Re: A-chlorination carbonyls with H2O2/HCl
« Last post by Hunter2 on April 21, 2025, 07:35:17 AM »
Quote
While using HCl I received mostly monobrominated product, some significant part of substrate and little trace of something more unpolar (dibromo derivative?)

You mean monochloriated product, do you?

Which Carbonyl reactant do you use.
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Organic Chemistry Forum / A-chlorination carbonyls with H2O2/HCl
« Last post by Parathormon on April 21, 2025, 05:34:07 AM »
Hello everyone,

I have some question regarding to aforementioned reaction - as of my experience procedure copy from HBr/H2O2 where man use 1eq carbonyl, 1.1eq HBr and 1.4eq H2O2 but using HCl instead do not lead to full conversion.


As of my TLC for such procedure using HBr I received 100% conversion and selectivity to monobrominated product.

While using HCl I received mostly monobrominated product, some significant part of substrate and little trace of something more unpolar (dibromo derivative?)



As of my literature research it can happen due to slow reaction between h2o2 and HCl and even below 30% conc of hcl chlorine is not appearing at all, instead of this HCl is slowly decomposing H2O2 to oxygen and water.


Question to You - is it possible to somehow challenge this problem and use this procedure or it is rather not recommended? I also didnt find any work or patent on such reaction (monochlorination of carbonyls by h2o2/hcl).
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Chemical Engineering Forum / Mixing Scale-up
« Last post by Collyrium on April 20, 2025, 11:03:55 PM »
Let's say I want to scale-up a reaction rom lab scale to pilot scale, there are defined parameters (Re, P/V etc) to get the RPM and power. Now my doubt is, How do I choose type of agitator, and how should I compare between different type of agitator?
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Chemical Engineering Forum / Re: NO2 reduction
« Last post by Borek on April 20, 2025, 12:34:16 PM »
Try contacting Elutia.  They make a TEA (Thermal Energy Analyzer) instrument. We used it to test for n- nitrosamines.  It first came out under Thermo, but I think Ellutia bought it from them.  The idea of the analyzer was to take the substances routed from a GC, pyrolyze them as they came out, then they were run through a could trap ( ours used EtOH and dry ice) and the left over gas went to the instrument.  The Instrument took the gasses (NOx) and reacted it with O3( O2 came in and was exposed to an electric arc to make ozone).  This chemoluminesced to produce red light which was measured.  There were other steps, but you get the.idea.  They might be able to help you.

Are you sure it is related to the OP question?
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Chemical Engineering Forum / Re: NO2 reduction
« Last post by marquis on April 20, 2025, 10:36:32 AM »
Try contacting Elutia.  They make a TEA (Thermal Energy Analyzer) instrument. We used it to test for n- nitrosamines.  It first came out under Thermo, but I think Ellutia bought it from them.  The idea of the analyzer was to take the substances routed from a GC, pyrolyze them as they came out, then they were run through a could trap ( ours used EtOH and dry ice) and the left over gas went to the instrument.  The Instrument took the gasses (NOx) and reacted it with O3( O2 came in and was exposed to an electric arc to make ozone).  This chemoluminesced to produce red light which was measured.  There were other steps, but you get the.idea.  They might be able to help you.
10
Chemical Engineering Forum / Re: NO2 reduction
« Last post by Borek on April 19, 2025, 05:43:35 PM »
Can't think of anything that can be done.

Reaction speed basically depends of concentrations (or pressure) and temperature - if you keep these constant, reaction speed doesn't change.

You can speed up the reaction with catalyst or slow it down with an inhibitor - but that requires adding something to the mix (changing container material won't change much, as this particular reaction takes place in the bulk).

Sometimes it is possible to speed up the reaction with ionizing radiation (UV and dental cement for example), but that's opposite of what you need.
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