Pure ZHO extraction solvent

[Loc Dog]

Another article that I could not cut and paste -

http://monash.edu/science/about/schools/chemistry/safety/explosive-substances.html

Peroxidisable compounds

Peroxide formation in laboratory solvents and reagents has been the cause of many accidents over the years. It is important that you can recognise which compounds have the potential to form peroxides.
Organic compounds that can form allylic or benzylic radicals (cyclohexene and tetralin) or radicals stabilised by an adjacent oxygen (most ethers) are potential peroxide formers. Diisopropyl ether is particularly dangerous. Aldehydes can also form peroxides, although they are not normally a problem. In general, pure compounds are more subject to peroxide buildup.
Alkali metals and their amides are converted to peroxides on prolonged exposure to air.

Testing and treatment for ethers containing peroxides

The peroxide test reagent is prepared by mixing the following solutions in a ratio of 10:1:1 (AS/NZS 2243.2 - Appendix D)

• ferrous ammonium sulfate (1% w/v solution)
• sulfuric acid (0.5 mol/L)
• ammonium thiocyanate (0.1 mol/L)

A red coloration on mixing approximately equal volumes of ether and reagent indicates the presence of peroxides. If peroxides are present, they can be removed by passing through a chromatography column containing activated alumina. About 80 g of alumina should be sufficient for a Winchester of ether. The ether should be tested before and after passing through the column.

http://monash.edu/science/about/schools/chemistry/safety/explosive-substances.html

 

[Loc Dog]

What about the "D" rating of dimethyl ether with BUNA or Viton seals?

Nevermind!!! Did not realize they made PTFE triclamp gaskets.

 

[SkyHighLer]

6 can cost 2x as much as 12 cans of butane, and (from what I've read) has slightly lower yields on the same amount of material/solvent used.

How is this better than butane ?? It is flammable, expensive, low yielding, and no overall safer than butane. I've heard of a much higher pressure, potentially pulling more unwanted materials/waxes through.

MZ12X comes in a 500ml can, most canned butanes are 300ml, and aren't pure butane, but a mixture of n-butane, iso-butane, and propane. If you're loading a closed loop system the ~20% of the propane is vented to atmosphere during loading...

We'll see about yield and what it's extraction window is...

As to flammability, I didn't see any warnings about it pooling like there are for butane...

I had a long talk with Ron at PureZHO today. They're contemplating removing the compressed CO2 from the 'formula' due to the pressure it adds. They don't yet have a Canadian distributor...

Oh, and the MSDS now says "Dimethyl Ether" ;-)

 

[Kcar]

The CO2 would be one of my concerns in closed loop.

 

[Loc Dog]

I could not live with myself, if I read this and did not share!!!

If I advocated, and worst happened, would feel/be guilty.

If some experts are willing to advocate, go ahead.

Personally, would not try for 3 years (but only talking recycling).

If there are early users, that use a recycler, they should have their solvent tested for peroxides. Posted how to do it a few posts ago.

 

[Loc Dog]

The CO2 would be one of my concerns in closed loop.

One of my concerns is, that it produces carbon monoxide when decomposing, which is incompatible, and may increase peroxide problem.

Will not make another post here. Some are strong advocates.

Company is a bunch of idiots. Their flagship product disappeared. They contradict themselves, and do not know what they are selling.

DO YOU WANT TO BE RESPONSIBLE IF SHIT GOES WRONG!!!

 

[Loc Dog]

GW,

I apologize, so much for dragging you into this!!!!!!!!!

You should not be imposed by this burden!!!!!


Be well, and run with the pack!!!!

Are they on stock exchange??? Would bet all I have they will tank in a month.

 

[Gray Wolf]

GW,

I apologize, so much for dragging you into this!!!!!!!!!

You should not be imposed by this burden!!!!!


Be well, and run with the pack!!!!

Are they on stock exchange??? Would bet all I have they will tank in a month.

No one drags the tattered old gray wolf anywhere he isn't willing to go, without having at least one arm gnawed and I haven't posted any definitive answers because I wasn't able to connect with my lab tech again before he left for the weekend, and our biotech is soaking up rays in Hawaii.

I myself am headed out on vacation Monday, so will try to get an answer from SPR's Joe before then. My organic chemistry simply isn't deep enough.

I am also still working on seals. Our valves are PTFE, but not the pump seals, which are of concern.

Probably could use passive reclaim like the Lil Terp, with alcohol and dry ice without mechanical issues.

 

[Loc Dog]

No one drags the tattered old gray wolf anywhere he isn't willing to go, without having at least one arm gnawed and I haven't posted any definitive answers because I wasn't able to connect with my lab tech again before he left for the weekend, and our biotech is soaking up rays in Hawaii.

I myself am headed out on vacation Monday, so will try to get an answer from SPR's Joe before then. My organic chemistry simply isn't deep enough.

I am also still working on seals. Our valves are PTFE, but not the pump seals, which are of concern.

Probably could use passive reclaim like the Lil Terp, with alcohol and dry ice without mechanical issues.

I am only concerned with this product in recycler's! Apologize, if I insulted anyone. Need to see testing. Have posted how to determine if peroxides are present. Do not know if GW's people can simulate many extractions, in short time, and test.

SAFETY IS #1!!!!!!!!!!!!!!!!!!!!!!!

Best wishes to GW!!!!

P.S. - If you are not going to do it safe, have someone else do it!!!!!

 

[Loc Dog]

I am only concerned with this product in recycler's! Apologize, if I insulted anyone. Need to see testing. Have posted how to determine if peroxides are present. Do not know if GW's people can simulate many extractions, in short time, and test.

SAFETY IS #1!!!!!!!!!!!!!!!!!!!!!!!

Best wishes to GW!!!!

P.S. - If you are not going to do it safe, have someone else do it!!!!!

I would wait for peroxide question to be answered, before exposing the gaskets in your appion.

 

[Gray Wolf]

Still researching pumps and seals, as well as cryo-pumping so as to not require seals, but did manage to contact Joe on vacation and pick his keen alleged mind on peroxides.

He said that Dimethyl ether peroxides are formed when the Dimethyl ether is exposed to moisture and air, in metal containers.

It forms metal salts that are brissant contact explosives, so a recycle system would have to remove that moisture before introducing air, but they would not likely be of concern in a single pass glass tube.

Adding "brissant explosive" to the formula makes it less attractive in a closed loop system, but I will continue to look further.

 

[G.O. Joe]

The hydrogen of methyl (CH3) functions is not peroxidizable in the way that methylene (CH2) or methine (CH) hydrogen is, which exist in the other ethers.
http://safety.dri.edu/Hazards/PeroxideFormingCompounds.pdf
For instance, isobutane (CH3)CH should be much more peroxidizable - t-butyl hydroperoxide is well known, and has been made from isobutane without difficult procedures. I doubt that a reference can be found for methoxymethylhydroperoxide formation in a container of DME under any condition likely to be encountered. Test it with peroxide tests, but I'd bet that the MSDS is leading you astray - others can be found that don't mention peroxide.
http://www.airgas.com/documents/pdf/001021.pdf

 

[Loc Dog]

This is what I found. Can not paste the chart, that is at their URL.

If it is pure dimethyl ether, it is more likely to form peroxides, from what I have read, not a Chemical Engineer.

http://monash.edu/science/about/scho...ubstances.html

Peroxidisable compounds

Peroxide formation in laboratory solvents and reagents has been the cause of many accidents over the years. It is important that you can recognise which compounds have the potential to form peroxides.
Organic compounds that can form allylic or benzylic radicals (cyclohexene and tetralin) or radicals stabilised by an adjacent oxygen (most ethers) are potential peroxide formers. Diisopropyl ether is particularly dangerous. Aldehydes can also form peroxides, although they are not normally a problem. In general, pure compounds are more subject to peroxide buildup.
Alkali metals and their amides are converted to peroxides on prolonged exposure to air.

Testing and treatment for ethers containing peroxides

The peroxide test reagent is prepared by mixing the following solutions in a ratio of 10:1:1 (AS/NZS 2243.2 - Appendix D)

ferrous ammonium sulfate (1% w/v solution)
sulfuric acid (0.5 mol/L)
ammonium thiocyanate (0.1 mol/L)

A red coloration on mixing approximately equal volumes of ether and reagent indicates the presence of peroxides. If peroxides are present, they can be removed by passing through a chromatography column containing activated alumina. About 80 g of alumina should be sufficient for a Winchester of ether. The ether should be tested before and after passing through the column.

If you are Chemical Engineer and do the test, it needs to be looked at over time.

Can you produce link to credible article, saying there is no way it would happen, in a recycler, exposed to air and moisture.

 

[Loc Dog]

Google ""dimethyl ether" accident peroxide". This was top listing -

http://www.ncsu.edu/ehs/www99/right/handsMan/lab/Peroxide.pdf

Putting quotes around dimethyl ether, reduces diethyl ether results.

Praxair says it will produce peroxides, spontaneously ignite or on heating.

http://www.praxair.com/~/media/North%20America/US/Documents/SDS/Dimethyl%20Ether%20C2H6O%20Safety%20Data%20Sheet%20SDS%20P4589.ashx

Late, and do not have time to post thousands of articles.

 

[Loc Dog]

In safety, pessimism is prudent!

Have worked for major pharm/chems, and saw the 7 year process they had for approvals. n-butane is stable, and safe, used properly. If you have doubts, have someone do it!!!!

I do not want to see one accident!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Please do not blast!!!!! If you must, do not do without -

OUTSIDE
Hose
Blanket
fire extinguisher
someone to help, if problem

 

[Loc Dog]

GW's best chemist backs my initial analysis. I leave it to them. I have no credibility, just found it first, and researched.

He will be back soon and give official analysis.

Do not care if they take months, and do long term tests.

Best to GW, and all at SP!!!!!!!!!!!!!!!!!!

 

[Loc Dog]

Anyone that wants to test, should expose inside to moisture and oxygen. In perfect system (not going to happen) would not be issue. Not vacuuming, and moisture exposure are major issues.

 

[Loc Dog]

Who would not want to use something the causes rogue brissant explosives.

 

[SkyHighLer]

Still researching pumps and seals, as well as cryo-pumping so as to not require seals, but did manage to contact Joe on vacation and pick his keen alleged mind on peroxides.

He said that Dimethyl ether peroxides are formed when the Dimethyl ether is exposed to moisture and air, in metal containers.

It forms metal salts that are brissant contact explosives, so a recycle system would have to remove that moisture before introducing air, but they would not likely be of concern in a single pass glass tube.

Adding "brissant explosive" to the formula makes it less attractive in a closed loop system, but I will continue to look further.

"For Dymel® A, Kalrez® is the only elastomer known which shows good resistance to swelling in laboratory immersion tests. However, mechanical factors in actual plant use could influence material selection. Silicone O-rings encapsulated in Teflon® are recommended generally for Dymel® A, including undercap filling machines. DuPont should be contacted for specific information."

http://www2.dupont.com/Dymel_Propellants/en_US/assets/downloads/h54883_Dymel_meet_the_challenge.pdf

Kalrez = FFKM

http://o-ring.info/en/products/by-compound/kalrez-ffkm/


"6.4 Propane cylinders used for DME-LPG blends should have appropriate seals made of HNBR (depending on additives and characteristics) or Teflon. Viton, the material usually used with LPG, is not compatible for use with DME-LPG blends containing DME at 20% weight." http://www.aboutdme.org/aboutdme/fi...00002001/IDA_DME_LPG_Blend_Recommendation.pdf

"Hydrogenated Nitrile Butadiene Rubber (HNBR), also known as Highly Saturated Nitrile (HSN), is special class of nitrile rubber (NBR) that has been hydrogenated to increase saturation of the butadiene segment of the carbon polymer backbone. Subsequent improvements to the material properties, over that of a nitrile rubber (NBR), include greater thermal stability, broader chemical resistance, and greater tensile strength.

HNBR is classified by ASTM as a DH-type polymer. This classification indicates 150ºC service temperature as well as less than 30% swell in IRM 903 oil. HNBR can be formulated to meet application temperatures ranging between -50°C and 165ºC."

http://www.sealseastern.com/hnbr.htm

 

[SkyHighLer]

The hydrogen of methyl (CH3) functions is not peroxidizable in the way that methylene (CH2) or methine (CH) hydrogen is, which exist in the other ethers.
http://safety.dri.edu/Hazards/PeroxideFormingCompounds.pdf
For instance, isobutane (CH3)CH should be much more peroxidizable - t-butyl hydroperoxide is well known, and has been made from isobutane without difficult procedures. I doubt that a reference can be found for methoxymethylhydroperoxide formation in a container of DME under any condition likely to be encountered. Test it with peroxide tests, but I'd bet that the MSDS is leading you astray - others can be found that don't mention peroxide.
http://www.airgas.com/documents/pdf/001021.pdf

Thanks, Dupont is frequently referenced for their research on DME, their dimethyl ether is called Dymel A,


"Dymel® A is not prone to peroxide formation in the pure state or in aerosol formulations."

http://www2.dupont.com/Dymel_Propellants/en_US/assets/downloads/h54883_Dymel_meet_the_challenge.pdf

That it can safely be stored in refillable propane style tanks for use as a household cooking and heating gas, and fuel for vehicles without a single mention of storage problems says something, you think? End user refillable storage tanks would not be free of moisture and air... Hmmm?