Gassing with HCL/CaCl2 (H2SO4 not required)

[Mercury]

I read the info on Rhodiums site regarding this gassing method, but I constantly read posts where bees are still gassing with HCl/NaCl/H2SO4.

According to the procedure, you simply need to react HCL with CaCl2 using 1:1 weight ratio, and you're done! Has anyone had a dream conducting this gassing procedure? It seems so damn simple.

[silenziox]

It works like a charm. Just for the record, I use 500ml erlernmeyer with side arm and 100ml pressure equalized addition funnel.

The procedure is found at

Rhodium's: Anhydrous Hydrogen Chloride  HCl(aq) + CaCl2

(https://www.thevespiary.org/rhodium/Rhodium/chemistry/equipment/calcium.hcl.generator.html)

[Rhodium]

What's the difference in simplicity between adding HCl(aq) to H₂SO₄ and adding HCl(aq) to CaCl₂ - or H₂SO₄ to a NaCl/HCl(aq) slurry for that matter?

It's just a matter of personal preference, and varying access to different sets of chemicals.

[Mercury]

It works like a charm. Just for the record, I use 500ml erlernmeyer with side arm and 100ml pressure equalized addition funnel.


Do you feel that a drying tube situated in series with the gas chamber and the outlet tube is necessary? According to what I have read, the HCl gas created with CaCl2 is much drier than creating the gas with H2SO4.

How much do you start with? I'm talking quantity for the HCl and CaCl2. You use an equal amount of both, right?

[silenziox]

Do you feel that a drying tube situated in series with the gas chamber and the outlet tube is necessary? According to what I have read, the HCl gas created with CaCl2 is much drier than creating the gas with H2SO4.

I haven't noticed any difference "passing the gas" using the H₂SO₄ method vs CaCl₂.

I've never encountered need for drying tube for any gassing method.

(I never calculate anything when gassing, j will water the and I dry everything in vacuum dessicator anyway.

How much do you start with? I'm talking quantity for the HCl and CaCl2. You use an equal amount of both, right?

HCl_(aq) amount depends of the freebase you're gassing, obviously. CaCl₂ is dirt cheap and you can even dry it and use it one more time

I usually just fill the 1/4 of the erlenmeyer with CaCl₂, Don't let it go too wet, use always excess. If it gets too damp, just replace it with fresh batch.

It's always good to dry the product in vacuum dessicator  

[Osmium]

Ca2SO4 is insoluble, I'd rather use NaCl.

[silenziox]

We were discussing about Calcium chloride (CaCl2), not Calcium sulfate (Ca2CO4)    ...

Then again, CaCl2 + H2SO4 = CaSO4 + 2HCl ...

edit: Quick search provided interesting links with patents and all concerning sodium bicarbonate, NaHCO3, calcium chloride, CaCl2, hydrochloric acid, HCL and "gypsum" (Ca2CO4·2H2O), CaSO4 and waste reduction program examples..[/red]

http://www.geocities.com/CapeCanaveral/Galaxy/6137/

Method of manufacturing of technically pure hydrochloric acid and other chemicals using waste from soda production, Patent App. P-280653, 19.07.1989, B. Borkowski, J. Król-Bogomilski

--------------------------------------------------------------------------------


Calcium chloride, which is the second product in the Solvay method can be used in the chemical industry, in order to reach calcium sulfate (white pigment, white gypsum), hydrochloric acid and gaseous HCl in a simple industrial unit process.



The reaction proceeds at the temperature not exceeding 100°C, according to the equation:

CaCl2 + H2SO4 = CaSO4 + 2HCl

Calcium chloride that is the second product of the Solvay process should be dissolved in water. Then one should add the 20°Be hydrochloric acid to this solution.

Concentrated sulfuric acid H2SO4 should be added to this solution dropwise.

During this reaction the solution should be continuously mixed and cooled down to 20°C.

The 20°Be hydrochloric acid is obtained in this reaction in the same reactor. This is the first variant.

The sulfate CaSO4 is washed with a diluted solution of Na2CO3 and filtered off or centrifuged. Then one can use it as white pigment or white gypsum.

The hydrochloric acid can contain a small amount of CaCl2, but it is sufficiently pure for many technical applications and uses.

However, there is also a second variant; We can dissolve gaseous hydrogen chloride in the saturated brine.

Hydrochloric acid may be also obtained by the well known reaction, using NaCl and concentrated sulphuric acid. However, that reaction requires heating to the temperature of about 600°C. It may be also obtained in the reaction of H2 with Cl2, but the temperature of that reaction is 2400°C. It is important that the reaction with CaCl2 does not require heating. On the contrary, the mixture should be cooled.

[Osmium]

Well, it's up to you, if you like removing a hard rock of gypsum from a flask the day after you gassed, be my guest.

Funny patent you quote there.

> The 20°Be hydrochloric acid is obtained in this reaction in the same reactor.

This is aqueous HCl.

BTW, the markets are overflowing with cheap gypsum due to it being an end product in sulfur removal from the exhaust of power stations. I doubt this process is being used industrially.

[abacus]

Mercury

HCL with cacl2 releases a tiny amount of HCL gas, its enough to gas a few grams of amine at most.

SWIM has experimented with all the gassing procedures discussed in the hive and has concluded the best is by far dripping H2SO4 onto HCL wetted NaCL, second would be dripping HCL into 98% h2SO4.

Forget the CaCl2 approach, its useless.

[silenziox]

HCL with cacl2 releases a tiny amount of HCL gas, its enough to gas a few grams of amine at most.


I've gassed a 116g batch with this setup, changing twice the
CaCl2. It takes time, and requires swirling the bottle every 15 seconds (this is where the shaker comes handy).

The CaCl2 'dessicates' the water out of HCl(aq), hence releacing the HCl(g).

Best setup seen so far is

Post 265503

(PoohBear4Ever: "Re: Bugs look out here comes the HCL !!!", Newbee Forum) ..
Tips from

Post 266084

(VideoEditor: "Re: Bugs look out here comes the HCL !!!", Newbee Forum) ..

[methlab]

I think the CaCl2 + HCl workes very good, i will never do it with H2SO4 again. I build a Osmium-like gassing apparatus, which workes very well. (0.5l sqeezable plasticbottle with hose/pipette on top, CaCl2 filled 2/3 in the bottle, which is covered 2/3 with HCl. After 5mins you can start to gas). I can recommend this method.

[Osmium]

Put some NaCl and H2SO4 into the bottle and it will work even better.

[Buster_Hymen]

>>HCL with cacl2 releases a tiny amount of HCL gas, its
>>enough to gas a few grams of amine at most.

>>SWIM has experimented with all the gassing procedures
>>discussed in the hive and has concluded the best is by
>>far dripping H2SO4 onto HCL wetted NaCL, second would be
>>dripping HCL into 98% h2SO4.

>>Forget the CaCl2 approach, its useless.

That's not true. A 1L wash bottle with a few inches of CaCL2 and HCl in the bottom will make enough gas to easily bring 15g of meth out of the base in toluene. And the bottle is STILL producing strongly at the end.

It's a great method for small amounts. No drying necessary.

[Photon]

Can one use MgSO₄ in place of CaCl₂? One of the issues with using Calcium Chloride is that it can be time consuming to get all the gas released from the (aq) HCl, but I know Magnesium Sulfate is a more efficient drying agent compared to calcium chloride.

[Organikum]