Distillate out the amine from an amine salt?

[IV]

Hallo,

higher fatty acids and an amine form an amine salt. Let us assume an amine
that has a boiling point lower than the boiling range of the fatty acids. Is
it possible to distillate out the amine completely from the amine salt to
get the whole quantity of free fatty acids?

Thank you.

[Frank]

Post by IV
Hallo,
higher fatty acids and an amine form an amine salt. Let us assume an
amine that has a boiling point lower than the boiling range of the fatty
acids. Is it possible to distillate out the amine completely from the
amine salt to get the whole quantity of free fatty acids?
Thank you.

I'd say only if you threw in a stronger caustic to free the amine from
the acid. Doing this you could also extract the amine without distillation.

[Poutnik]

Frank posted Sat, 22 Jun 2013 08:45:57 -0400

Post by Frank

Post by IV
Hallo,
higher fatty acids and an amine form an amine salt. Let us assume an
amine that has a boiling point lower than the boiling range of the fatty
acids. Is it possible to distillate out the amine completely from the
amine salt to get the whole quantity of free fatty acids?
Thank you.

I'd say only if you threw in a stronger caustic to free the amine from
the acid. Doing this you could also extract the amine without distillation.

OTOH, direct destilation could thermally disociate the salts,
but with high danger of amine destruction,
as amins are know not to be stable compounds.

[Poutnik]

IV posted Sat, 22 Jun 2013 14:42:19 +0200

Post by IV
Hallo,
higher fatty acids and an amine form an amine salt. Let us assume an amine
that has a boiling point lower than the boiling range of the fatty acids. Is
it possible to distillate out the amine completely from the amine salt to
get the whole quantity of free fatty acids?

If both the free fatty acid and the amine are to be obtained,
I suppose the optimal way is multistep one.

1/ chemical release of amine by strong base

R-NH3(+) Ac-COO(-) + NaOH -> R-NH2 + Ac-COONa + H2O

2/ amine separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.

Presence of the organic solvent can provide
also stability of the amine.

E.g. Mixing of n-butanol or i-amylalcohol
with aquaous solution/suspension of amine salt,
where is added NaOH solution.

3/ cleanup of amine ( purification / separation from solvent / drying )

4/ chemical release of acid from Na salt by strong acid

Ac-COOH + HCl -> Ac-COOH + NaCl

5/ acid separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.

6/ cleanup of the acid ( purification / separation from solvent / drying

[Poutnik]

Poutnik posted Sat, 22 Jun 2013 15:43:33 +0200

Post by Poutnik
1/ chemical release of amine by strong base
R-NH3(+) Ac-COO(-) + NaOH -> R-NH2 + Ac-COONa + H2O
2/ amine separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.

With step one, of course... :-)

[Poutnik]

Poutnik posted Sat, 22 Jun 2013 15:43:33 +0200

Post by Poutnik
If both the free fatty acid and the amine are to be obtained,
I suppose the optimal way is multistep one.
1/ chemical release of amine by strong base
R-NH3(+) Ac-COO(-) + NaOH -> R-NH2 + Ac-COONa + H2O
2/ amine separation from aquaeous phase
by extraction or destilation, optionally integrated with step 1.
Presence of the organic solvent can provide
also stability of the amine.
E.g. Mixing of n-butanol or i-amylalcohol
with aquaous solution/suspension of amine salt,
where is added NaOH solution.
3/ cleanup of amine ( purification / separation from solvent / drying )

But if just fatty acids are needed,
than one can start by step 4 directly.

Post by Poutnik
4/ chemical release of acid from Na salt by strong acid
Ac-COOH + HCl -> Ac-COOH + NaCl

R-NH3(+) Ac-COO(-) + HCl -> R-NH3(+) Cl)-) + Ac-COOH

Post by Poutnik
5/ acid separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.

And extration by non alcoholic solvents,

Post by Poutnik
6/ cleanup of the acid ( purification / separation from solvent / drying

[Frank]

Post by Poutnik
IV posted Sat, 22 Jun 2013 14:42:19 +0200

Post by IV
Hallo,
higher fatty acids and an amine form an amine salt. Let us assume an amine
that has a boiling point lower than the boiling range of the fatty acids. Is
it possible to distillate out the amine completely from the amine salt to
get the whole quantity of free fatty acids?

If both the free fatty acid and the amine are to be obtained,
I suppose the optimal way is multistep one.
1/ chemical release of amine by strong base
R-NH3(+) Ac-COO(-) + NaOH -> R-NH2 + Ac-COONa + H2O
2/ amine separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.
Presence of the organic solvent can provide
also stability of the amine.
E.g. Mixing of n-butanol or i-amylalcohol
with aquaous solution/suspension of amine salt,
where is added NaOH solution.
3/ cleanup of amine ( purification / separation from solvent / drying )
4/ chemical release of acid from Na salt by strong acid
Ac-COOH + HCl -> Ac-COOH + NaCl
5/ acid separation from aquaeous phase
by extraction or destilation, optionally integrated with step 4.
6/ cleanup of the acid ( purification / separation from solvent / drying

Nice details and very nice to see chemical discussion here ;)

[IV]

"Poutnik" <***@privacy.invalid> schrieb im Newsbeitrag news:***@news.eternal-september.org...

Let us think not of a laboratory synthesis, but of a technical process:
there must no salt waste be produced, therefore alkali can not be used.

To prevent formation of the amide, tertiary amines have been proposed. Can
distillation of amines like trimethylamine or diethyltrimethylamine under
atmospheric air, atmosperic pressure and temperatures under 200 °C destroy
the amine, e.g. by forming the amide, amine oxides or nitroso amines?

Thank you.

[Poutnik]

IV posted Sun, 23 Jun 2013 18:43:35 +0200

Post by IV
there must no salt waste be produced, therefore alkali can not be used.

That is strange,
as the proposes procedure is considered as a common technical process.

Post by IV
To prevent formation of the amide, tertiary amines have been proposed. Can

I supposed the amined is given and cannot be chosen.

Post by IV
distillation of amines like trimethylamine or diethyltrimethylamine under
atmospheric air, atmosperic pressure and temperatures under 200 °C destroy
the amine, e.g. by forming the amide, amine oxides or nitroso amines?

Important it thermal stability of the salt.
BTW, why not vacuum destilation ?