DE2359863B2 - METHOD FOR PRODUCING GLYOXYLIC ACID - Google Patents

Description

K ₂₂

R23

K ₂₈ IN K ₂₆ ,

R ₂₄ . R ₂₇

2 /, A '

contains, wherein R ₁₀ , R ₁₁ , R _{12 is} a saturated or unsaturated, straight-chain or branched, aliphatic hydrocarbon radical, where two of these radicals can optionally together form a single saturated alkylene radical or fine oxydialkylene radical, or a radical of the formula

- (CH ₂₎ ,, - [O - (CH ₂ I _n Jr OH

with μ es ^ f \ ijo r 3 and ία -! to \ Q b £ d £! £ t £ n where at least one of the radicals R ₃₀ , R _n and R _{12 is} an arylaliphatic radical of the formula

where R _{9 is} a divalent, saturated or unsaturated, straight-chain or branched aliphatic hydrocarbon radical and the totality of the radicals R ₁₀ , R ₁ and R _{12 has} less than a total of 40 carbon atoms, R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ one the above for R ₁₀ , R ₁ ? and R ₁₂ have the meanings given, with the possibility for two djgSgr Rggjg, T usamm gn to form a single divalent radical, only for two radicals that come from the same nitrogen atom

with; j = 2 00; r I and in = 1 to 10, where at least one of the symbols R _Jg , R ₁₉ , R ₂₀ and R _{21 is} a monovalent aromatic hydrocarbon radical that is either purely aromatic, arylaliphatic or aromatic with linear or branched , saturated or unsaturated aliphatic radicals as substituents, and all of the radicals R ₁₈ , R ₁₉ , R ₂₀ and R _{21 have} more than 15 and less than 40 carbon atoms, R22. Ra. R 2 ». ^R 25, ^R 26 and R 27 have the same meanings as given for R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ ; and R _{28 has} the same meaning as indicated _{for R 17;} and all of the radicals R ₂₂ , R ₂₃ , R24. R ₂ 5. R26. R27 and R _{28 have} more than 8 and less than 40 carbon atoms, y has the meaning of 1, 2 or 3, A ^y 'represents the hydroxyl radical or an anion, so that AH means an inorganic or organic acid.

2. The method according to claim 1, characterized in that that the adjuvant is soluble in water at the concentration contemplated.

3. The method according to any one of claims 1 or 2, characterized in that the Ad is selected becomes from the group:

Tribenzylamine, bis (dimethylamino) diethyl

ether;

the hydroxides and halides of di-

methyl-benzyl-octadecylammonium;

the hydroxides and halides of di-

methyl-phenyl-dodecy! ammonium, dimethyl-

phtiuyl-hexadecylaminonium;

the hydroxides and salts, in particular

the dihalides of 1,6-bis- (triethylam-

monio) hexane, 1,4-di- (n-butyI) - 1,4-diazohm-

bicyclo [2.2.2] octane, 1.4 - di - (η - dodecyi) -

1,4-diazonia-bicyclo [2.12] octane.

65 The present invention relates to another

for the production of glyoxylic acid by cathodic reduction of an aqueous oxalic acid solution.

■ f.

ü) quaternary ammonium salts of the FprrneJ *

R ₂ 3 ~ ^ -R ₂₁₁ - ^ R _2ft , 2 / _y A ^

ti?

f Ιιϊι Patent 2240 759 is a method of manufacturing /.ur Glypayisiiure kathodssche by reductive *. S 't, on an aqueous oxalic acid solution which is free from

"A strong mineral acid is, \ n an electrical power supply

direction, which has a cathode, a cathode chamber, "cmc ils Trpnndiaphfagma trained cation

aubtnüschinefeibmn, one Ancjücnkarnrncr and one
Mncde aujjyeist, whereby dcrKalliply) contains in closed, wherein Ri _o ,; RuiiRi ₃ a gcsiiÜigt ^ tiOdcr-un-

Circle is performed, where he 4n> the surface; der fiältcni ^ le ^ dkettigeifiitjcjlicr ve r ^ VV-C igi en j | ΐίΐΙί prTa-r

Kitthpdc circulates and vvobei er .arijeirier) ri ;; end of ■■ - ■ « ^: --'-- ■ - -a.Sct-L · ': ^ • ii.c-rrii .. ■";: .. . ':. .:.-_ ,. ': ■■ sy:. ·.

The cathode chamber was removed and then ar ^ ifodcrcn

At the end of this same chamber, is reintroduced, '»And the temperature of the catholyte between; 0 and

70 ⁹ C, preferably between 5, and 35 ⁰ C,

described, which is marked by the fact that the ^ catholyte 0.00005 to \% besdmmterr ^ - ^ '■'"'** - ^&

Contains additives. 'Diirch' i this. ? 5
^ Adjuvants in particular make it possible:

a ^ sscrßlbiTrc ^ t means, wherebyj ^ two bi-ncrijialls ^ usammeri ejncnunzigen

,, 'ffclicser Rqstelgegebi-ncrijialls ^ usammeri ejncn ^ single f "jge; sattigtcn |; Äj | yJen ^

l ^ ^ g

jge; sattigtcn |; Äj | yJ, en ^
| bpdeh; can || bder a remainder ^ of the Fpniiel

, fpr

to Io

aliphatic radical of the formula

to use commercially available oxalic acid for the production of glyoxylic acid without this having to be luikrystallisiert several times,
To use oxalic acid of various origins, without it being necessary to subject it to a special cleaning treatment or to take special precautions with regard to the type of device and the ions originating in it,

the WTissstoffbildung on the cathode in the To reduce the electrolysis of oxalic acid, which enables better electrical yields to be obtained (A reduction in the electrical yields corresponds to the formation of hydrogen).

The present invention is the use of new nitrogen-containing adjuvants in the Production of glyoxylic acid by cathodic reduction of oxalic acid.

The invention therefore relates to a process for the production of glyoxylic acid by cathodic reduction of oxalic acid according to patent 22 40 759, which is characterized in that the catholyte 0.00005 up to 1% by weight of an adjuvant or an additive from the group of

a) tertiary amines of the formula

C ₆ H, - R ₉ -

10.

R,

\
Γ

is, where R _{0 is} a divalent, saturated or unsaturated, straight-chain or branched aliphatic hydrocarbon radical and the totality of the radicals R ₁₀ , Rn and R _{12 has} less than a total of 40 * carbon atoms, R _X3 , R ₁₄ , R ₁₅ and R _{16 have} one of the have the meanings given above for K ₁₀ , R> 1 and R ₁₂ , the possibility for two of these radicals to together form a single divalent radical exists only for two radicals which are carried by the same nitrogen atom; wherein the number of carbon atoms of the radicals R ₁₃ , R ₁₄ , R ₁₉ and R _{16 is} as defined below; and the presence of an araliphatic radical among the radicals R ₁₃ , R ₁₄ , R ₁₅ and R _{16 is} not necessary, R _n

is a divalent aliphatic or arylaiiphatic hydrocarbon radical whose aliphatic chain or aliphatic chains can be interrupted by oxygen atoms, the free valences of the radical R _{17 being carried} by aliphatic carbon atoms and the total number of carbon atoms in the radicals R ₁₃ , R ₁₄ , R _t5 , R ₁₆ and R _{17 are} above 6 and below 40, Ri ₈ , R ₁₉ , R ₂ O and R _{21 represent} a saturated or unsaturated, straight-chain or branched aliphatic hydrocarbon radical, two of these radicals optionally together being a single saturated alkylene radical or an oxydialkylene radical or a radical of the formula _ _(CHA _ _[O _ _{(C Hj)} ^ _OH

NR ₁

b) bitertiary amines of the formula

fc -R ₁₇ --N

R ₁ * Rio

c) quaternary ammonium salts of the formula

R20

3 »- • "• 21»

-If--

with η = 2 or 3 and m = 1 to 10, where at least one of the symbols R _a , Ri ₉ , R ₂₀ and R _{21 is} a monovalent aromatic hydrocarbon radical. which is either purely aromatic, araliphatic or aromatic with linear or branched, saturated or unsaturated aliphatic radicals as substituents, and all of the radicals R ₁₈ , R ₁₉ , R ₂₀ and R _{21 have} more than 15 and less than 40 carbon atoms, R ₂₂ ,. R23. R24. R25 “R26” to R _{27 have} the same meanings as given for R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆

to, own; and R _{28 has} the same meaning as indicated _{for R 17;} and all of the radicals R ₂₂ , R23. R ». R25. Ra >> R27 and ^R 28 has more than 8 and less than 40 carbon atoms, y has the meaning of 1, 2 or 3, A ^{ye is} the hydroxyl radical or a

Anion represents so that AH, an inorganic or means organic acid.

The exact nature of Α ' ^θ is not a characteristic of the invention and one can get such an anion through

Another possible meaning for A ^y ° besides a hydroxyl residue is the nitrates, sulfates, phosphates, sulfonates, dicarbonates,, oxalates, halides and especially the chlorides and bromides ; '';r; and call iodide,,; r

. -, - >>"s | The inventively used adjuvants ■ are häuptsächlich'diejenigienVdie are soluble in water at the drawn in 'considered ^one concentration; in particular, it is preferable to choose A * ⁰ so that jdieKe solubility is present.. ,
"' As adjuvants that can be used, one can in particular mention: benzylemih, (dimethylamino) ethyl ether, the hydroxides and salts, especially the halides of dimethylbenzyl-do- # ecyjammonium, diaynyl-bcrizyl-dodecylammonium, jk i-dimethyl-benzyl-teiradonium , Diethyl

ift rbenzyl - tetradecylammonium, dimethyl - benzyl-

gf hexadecylammonium, diethyl benzyl hexadecyl

ψ ammonium, dimethyl-benzyl-octadecyiammonium,

I »; Diethyl - benzyl - octodccylammonium, dimethyl

|| benzyl - eicosylammonium, diethyl - benzyl - eicosyl-

|| ammonium, dimethyl - benzyl - docosylammonium,

ψ Diethyl-benzyl-docosylammonium; the hydroxides

|; and salts of dimethyl-phenyl-dodecylammonium,

H dimethyl - phenyl - hexadecylammonium; the hy-

ψ droxyde and salts, especially the dihalides

of l, 6- (triethylammonium) -hcxane, l, 4-di- (n-butyl, 4-diazonia-bicyclo [2.2.2] octane, 1,4-Di- (n-dodecyl) -l, 4-diazonia-bicyclo [2.2.2] octane (see examples on p and 9).

The temperature of the catholyte is generally between 0 and 70 ^J C. and preferably between 5 and 35 ° C.

As metals, the cathodes in the invention Process can form one can mainly lead, cadmium, mercury and the amalgams as well as the alloys of these various metals, especially with silver, tin and antimony to name. The anode of the electrolytic cells used in the invention consists in practice of one electrically conductive, electrochemical in the anolyte and under the working conditions envisaged stable material. As materials that are suitable for the anode, one can use the metals and : 'Metalloids, such as platinum, placed

Titanium. Graphite, lead and its alloys, in particular with silver, antimony and tin.

The separating diaphragm of the anode and cathode chambers is preferably a cathion exchange membrane. The nature of the same is not a characteristic of the invention. So one can use aiie known membranes, msbcBondc c the nomögciicn Μ € ίΏυΓαϊ> € and the heterogeneous membranes. These membranes can optionally be reinforced by an insert. In order to be able to carry out electrolysis operations for a longer ± <> duration, it is preferred

ti membranes to use under the action

a fro various constituents of the catholyte and

of the anolyte are stable and do not swell. The membranes which can be used can in particular be those in

I; US Patent 26 81320 and in the French

%: French patents 15 68 994, 15 75 782,

! · - ■ 15 78 019, 15 83089, 15 85 187 and 2040 950 to name.

UiG rviinavreniiTnat uvt TVB-rwn «* vwcc> τ» ν »Β> νΐαΞΐΙϊ

'p (measured as in the French patent

15 84 187) is preferably over 60%.

The one used in the process according to the invention “Atholyl essentially contains water. Oxulaiitire, 'Glyoxylic acid, one or more adjuvants one for'Former ί to IV, possibly a Rlnrkc Mineral sliirc like sulfuric acid; one · beyorzugi it, however, not to use such a sentence,

The Katholyi: can ^r m start of electrolysis only contain oxalic acid without glyoxylic; as üer Kätholyt can end ^ electrolysis only glyoxyl-'säure without oxalic acid, The Konzentralionen In oxalic acid and glyoxylic acid can constant Seih when working marikontinuicrlich, or variable when discontinuously arbeitel, or during of starting a continuous operation, ""

The concentration of oxalic acid is lower than the saturation at the temperature in question; in general this concentration is more than 2% by weight; this value relates in particular to the constant concentration when working continuously and the final concentration bc-i when working discontinuously. The concentration of glyoxylic acid is generally 3 to 25% by weight, preferably 5 to 15% by weight, these values relating in particular to the constant concentration of glyoxylic acid during a continuous operation and the final concentration of this acid in the case of discontinuous operations. As has already been stated above, the concentration of the adjuvant in the catholyte is generally between 0.00005 and 1% by weight. These concentrates are preferably between P ⁰ MOl and 0.5%; the use of these small amounts has the advantage of being able to omit removal of the adjuvant from the glyoxylic acid produced, since this adjuvant then has practically no adverse effect on the qualities of this acid.

The catholyte can also, if appropriate, reaction by-products in small amounts, in general less than 1%.

An aqueous acidic solution is preferably used as the anolyte. The exact nature of this anolyte is k ^ in a characteristic of the invention, since the The main purpose of the anolyte is to ensure electrical conductivity between the two electrodes. In general, aqueous sulfuric acid and phosphoric acid solutions are used. The concentration these solutions are generally between 0.1 and 5 mol / l, preferably between 0.5 and 2 mol / l.

The current density at the cathode is generally! between 3 and 50 A / dm ² , preferably between 10 and 35 .Μάη ?.

Any of them can be used in practicing the invention known electrolysis devices, for example those in the above-mentioned patents and in particular dr Belgian patent 7 57 ί 06 described, use.

However, Ivian prefers the use of electrolytic devices with fixed electrodes, making the achievement of compact devices, in particular Filter press type devices made possible. The electrodes and the Separating diaphragm arranged in parallel planes.

In a likewise advantageous manner, the KaihoSyten and the Asolytss can circulate in their respective chambers, which enables better results to be achieved.

i ^ Finally '** one can "between the" electrodes ^
-'and the separating diaphragm "separators :, or, << Ap- / Katholytnundiie standstuckr ^ for example tissue" or grid ^ on - ^^ Kanimern of the ^ cell

demand "->. < ^T ^ ^% ^ * ά &''',"? £ j / "^ DieTCreise, in ^ de

corresponding

Dic ^r following examples serve to illustrate the

^ In derVBeispielen vcrwendete / whandelsubhche '' oxalic lsi cine'na'ch in the atentschrift of the French ^ 3 31 498 and in British Patent Specification 'techniques described 11487/1915 produced, acid, wherein the different lead performed reactions to a QxalsaurelÖsung, dieahi Va "uum dried and is then filtered off with suction; esihandelt is a Öxalsäure dihydrate with a Reihheits-, degree of about 0,9,2%.

Examples 1 to 9

A number of attempts are made to reduce oxalic acid; these various attempts differ in the nature of the adjuvant used. The electrolytic cell in which this; Experiments to be carried out have the following! \ Characteristics:

The two electrodes are rectangular lead plates.

The usable surface of these electrodes is 0.8 dm ² .

The cathion exchange membrane is of the heterogeneous type: crosslinked sulfonated styrene-divinylbenzene copolymer. dispersed in a material reinforced by an insert in the form of a fabric made of polyvinyl chloride.

Permselectivity, measured in 0.6 m-KCL: 77.5%.

Substitution resistance, measured in 0.6 m-KCL; 7 ohm · cm ^e.g.

Distance between electrodes and membrane: 3 mm.

Table 1

zo

30 35 "equips is " ty * 7ir '' ^ ^ * 1- '? &< ₍ . m circle of the catholyte, lsl 'also a heat exchanger provided ' ^/ * ¹ ^ '"% ■ ^r ' The electrolysis conditions are as follows:

Current density: 25 A / dm ² .
- Voltage: about 5.25 V.
Temperature: 25 ° C.

Circulation speed of the electrolytes on the electrodes: 1 m / sec.
Catholyte introduced at the beginning: 21 of an 8 percent strength by weight aqueous oxalic acid solution (commercially available oxalic acid).
This solution is continuously electrolyzed,

After one hour, 25 g of commercially available oxalic acid and then 25 g are added to the catholyte this acid every half hour.

During this entire period of time fangi-man the hydrogen escaping as a gas via a water trough and tracks the electricity yield that corresponds to this evolution of hydrogen gas. When this yield reaches a value of 6 to 12%, the special adjuvant is added to the catholyte in each experiment. One measures the volume of the generated hydrogen in the hour following the addition of the adjuvant and calculates the corresponding Current efficiency. The results obtained with the various adjuvants below are listed in the following tables:

circulate, each have a ^ expansion vessel ^,

■ ---- '■ -> - "' - · - ■ -'-- ■" * ' Discharge lines * dis-

Example of the adjuvant

1 N- (CH ₂ -Q ₁ H ₅ ) J

■ 2 ■ - - tiCHihN-tCH ^ -0- (CH ₂ J ₂ -N (CHj) ₂
CH ₂ -C ₆ H ₅ t

ΐ
CH ₃

CH ₃ -N®

Duration of the momentary concentration Mean current Elcktrclyse current yield of the adjuvant yield (in%)

before addition (in %) em- in fflM / i in the on the

of the adjuvant speaking of the catho- addition of the

H ₂ generation lytes with adjuvant follow-

at the point of its addition the hour

the encore

of the adjuvant

2h 15 mn 8 1 1.5

h 20 mn 8.4 5 5.1

1 3.2

h 48 mn 12

CH ₃ C ₆ H ₅

CH ₃ -N® I ^e 3 h 20 min

C ₁₂ H ₂₅

CH ₃ C ₀ H ₅

CH ₃ - Ν® 0ΗΘ 3 h 20 min

C ₁₂ H ₂₅
In general the abbreviation mM millimole is used

8.9

2.8

3.9

4.7

609 529/500

Table 2
At piel Art dc Adjuvan

As

Ci

7 -ΐ

' ¹

2; 3.5'9J3.63 10

■: H'k

^l &' Duration of- Momentary Con / enlniiion Mean Current- *

" Electrolysis current bulge de adjuvant yield (in%)" Λ

,>, before addition, (in %) ent- in mM / I in in the on the ' _ijS

of the adjuvant speaking of the catho- addition of the ν_ϊ

atf π #. i Λ.Ά.μμΛΜΛ m ^ M Il A W ΜΛ ft W ^ A ΨΡ

Hj-Erzcugung lyten with adjuvant follow- ψμ <Μ

? uiti time of his adding the hour

the encore

de adjuvant ■>,> t ,, _,

- 6.4

λ : w

M- ⁹

(C ₂ Hj) ₃ N- (CHA-N (C ₂ Hs) ₃ 2Br ^ 5h CH ₂ -CH ₂

8 'Ti-C ₄ H ₉ -N-CH ₂ -CH ₂ -N-Ii-C ₄ H ₉ 2 h 18 mn 9.5

% ■ -> ■ t-Λ CH ₂ -CH ₂ V-- '

_{2 2}

3-C ₁₂ K ₂₅ -Il-CK ₂

CH ₂ CrI ₂

nC, ₂ H ₂₅

CH ₂ -Ii 2! ^ß h 17 mn 7.2

6.5

1.5

Claims (1)

23 69 # 63 - ,,.; ί - Yerfohrenpr ^ rstellung, vpn Qiyoxyjsüiirc ''; * jj * \ Λ "h". ^. t- I "ftf- _ J! ^ ν I *. - »** ΤΪ ~ * ~ 1 · -ΐ1-ΛΪ ^ *. ^ RilAd ^ \ β # Λ I SVJ« ■ ft Β «Α tfVSft._ L ^- ' ά) .tertiary amines of the formula ' 10, be worn bestcjn, wherein the number of ■ 'Kohienstoffaiome the ikesic R ,,,, R, _4, R, _s and R _{16' v} as nachstcheHu is defined and the presence / fine araliphatic radical among the radicals R _13, V 4 Ris und'Rjü not necessary Wt, R ₁₇ is a /.wci-'$ valent aliphatic or arylajjphatischer coal% $ ⁱ jcnwasscrsto'ffrest | "R, whose aliphatic trowel / -.? 'or aliphatischc chains by oxygen atoms.' . ', Can be interrupted ;, wherein the free V «i- ^ .10 turbulence of the radical R ₁₇ from aliphatic hydrocarbons.''''are supported stoffatomcn and Gcsamt- ■''' -. 'junzahl the Kohlcnstprfätoni | of the radicals R ₁₃ , R ₁₄ , N ₂ b) bitertiary amines of the formula Ri 3 Ris NR ₁₇ -N R ₁₄ R ₁₆ c) quaternary ammonium salts of the formula γΐ 8 K ₁₉ - ^ - K ₂₁ , If, A '" R20
d) quaternary ammonium salts of the formula "'( R ₂₀ - and R ₂₁ a saturated or unsaturated, -is" vgcradketfigen or branched aliphatic carbon dioxide ¹ IjKi lenwässcr'stoffresf dars.tejlcn ^ with two of these -'- ^ - "Resie given , Ju'siymmen can form a single saturated alkylene radical or an oxydialkyl radical or a radical of the formula