DE1668273C - Process for the production of glyoxal - Google Patents

Description

¹ Ah flow through a mixture of aqueous It is already known to carry out an Auiyic ι _KataJysator fcindo glyoxal by oxidation. In the case of ethylene with aqueous nitric acid in counter- ^ ^mp _t . ",, Y _{f> rlil} . _hen processes will produce ethylene and salt from a palladium catalyst. Continuous in ^ ^ _nitrogen This reaction is, however, even at maximum cape ^rea ™. 'Reaction medium fed in, with the catalyst concentration slowly and proportionally withdrawn in the medium continuously and ineffective because it is recovered from lossy side reactions and accompanied by the reactions through which the glyoxal itself of the catalytic converter ^. ^ _{The exiting) is} oxidized. ^Uonsm VZ * Äthvlen-containing gas stream can I lli i di Rkti t after 5 to "" ^^ [f ^ d di G

is xydated. VZ * Äthvlen containing gas stream can

Generally, the reaction is "are ^^ [f ^ ckoeführt to the overall 8 ended hours, and the selectivity of glyoxal io ^zwec * ^m ^ ^lg J" only after 5 to "! ^ Increase?. The secondary sample Carries only 60 to 65 weight percent A loading ^ f ^ JZZJ _m d nitrous oxide are vorschleunigung the reaction is of course desirable DUCTS Λ "," _ri "'exit gas stream is removed, value, in order to increase the yield of glyoxal. preferably tion vessel ^ m _reac to .iick-

The aim of the invention is to provide a method before the ethylene in

after the ethylene more quickly and efficiently to glycidyl * 5 -geführt ™ J ~, _uTiewtpSe glyoxal produced can be oxidized oxal. ^{: | S c} _u . ^ 'Γ;, Γ- I, Vunu / u technical Zv: ken

The invention relates to a method for producing directly as water _c - ^ ^ _n ^^ ^ _{R £} ._

treatment of glyoxal by the oxidation of ethylene with waste. ^, _{Hodcn with} anschlid vein aqueous, 1 to 60gewichtsprozentiger nitric nigung according bckann lii _{ti || ation} statthulen.

in the presence of palladium metal or a palladium *>-> nzenmcrung duη! . _the ^ ^

medium compound. which is characterized by BehändNj. "Iedergesd, .., en,

that the oxidation is additionally carried out in the presence of one of the Kata.ysa j « _{by Absu jun}

water-soluble lithium salt performs. and «as rc s hdn. ^ ^u ^ Polyacnl.ntril

The catalytic mixture can thereby hcrge through Akm.koWe H _{neutralization d} ,, _Rc .

be assumed that the lithium salt to palladium or "5 or * f ^un l" r.lciumtarbonat or by the palladium compound in the aqueous nitric tK ^ ^ m ^ ^^^ un al acid go. The preferred lithium salts ^ * ""'' ^v; "^ _{nn also for} removal are lithium chloride and lithium nitrate; but also ion exchange ^ «. in ^rt ""wr

other iihiumsal.e. such as nitrite, sulphate or lithium carbonate, cata- lisXn veru _luc bonate, can be used. The palladium 3o den. On the other hand, ^a " ^e " ^ ηίαΐοη _d "mhen is preferably in the form of a divalent palladium treatment by e.ne ^Kura J ^" ^l " ^at ^ _cleaned , l _s diumsalzcsf /. B. Palladium (II) chloride, palladium - solution DESCAL-mt be where s ^ ch P 8 's u _b' (Il) nitrate or palladium (II) sulfate, supply used aqueous Glvoxaldcst Hat and J · "^ ^ck" ^ J ^ ¹ is presumably the Lithium salt results during the reaction. The catalyst can act as a complex with the palladium, which is probably a more effective catalyst than the original Palladium method. _e ^ _on Chen W dium or the original unrein.gungen palladium compound is prepared by treating the uiyoxanosung because it is substantially more soluble and thereby be removed by electro-osmosis, higher concentrations of dissolved palladium in the invention will hereinafter ^ on the basis of

Reaction mixture are obtainable. 4o execution examples are explained in more detail, with all

The concentration of the palladium metal or the quantities given are based on weight. Palladium compound is preferably from 0.01 to

2 percent by weight of the reaction mixture. The example 1

_Molar ratio of the lithium salt to palladium in the αΓ; \ ^ Μ (- ^ Ola «

The reaction mixture is preferably about 1: 1. 45 In a with a ^ ^r \ 2 «™ J5 ,, ^ The admixture of some sodium nitrite to the receptacle was a mixture of 1000 parts of M ^ iger action-gcmisch facilitated the dissolution of the cata-aqueous nitric acid and 2 5 ^eggI 5 ?. .1 "^ ™ Vrde lysators in reaction mixture. The chloride is preferably introduced. This mixture; the molar ratio of sodium nitrite to lithium salt in ethylene in an hourly amount of 180 parts of the reaction mixture would be less than 1% at 40 ° C passed through

The reaction is preferably precipitated using metal. There were U.M leue carried out by technically pure ethylene. A lithium chloride added, whereupon the ^ a adium mixed of ethylene with other gases, e.g. B. Ethylene was rapidly dissolved. By gas-pressure c ^ Ethane-Gcniische, can be used, although it matographie one notes that the exiting it is preferred that no other olefins in a large gas stream apart from unchanged ethylene nor amounts of ace are present as the purity of the glyoxal contained taldehyde and nitrogen oxide After 5 hours is adversely affected by this. Most of the palladium fell as a result

The reaction is carried out in 1 to 60, preferably 10 to the consumption of the nitric acid and ^ s end of the 25 weight percent nitric acid. There response was displayed. A total of 44 liters of nitrogen dioxide or a mixture of nitrogen oxide or ethylene were absorbed, and the reaction mixture, with excess oxygen and the remaining 73 parts of glyoxal (determined by reaction with nitric acid) can be used, so that cyclohexylamine is used to precipitate the ships Base further amounts of ethylene and for obtaining a determination of the unreacted Cyclnaexyiamins, higher concentration of glyoxal in the reaction * - Vr, e by F. Beck and O. Grass in ιder Zc writing fur can be oxidized mixture Thereby, the analytical 6 _5. Chemie, 147, pp. 9 to 12 11955] that subsequent concentration of the glyoxal is made easier, which corresponds to a selectivity of 80%. The process can be carried out batchwise as the lithium chloride and the remaining components can also be carried out continuously. In the former case, palladium salts were recovered by

that the reaction mixture was separated by anionic lithium and sodium salts by precipitation

(JCO ₃ ² ') and cationic (H ⁺ ) exchange resin columns and ion exchange as in Example 1 removed. The ·

was passed through. Then the glyoxal-glyoxal solution was concentrated by distillation,

solution by vacuum distillation (below 50 Torr),

Cleans and concentrates, with a 40% S B e ι s ρ ι e ι ο

aqueous solution resulted, which for normal use by a mixture of 9 parts of Palladtum (II) -

was sufficiently pure. Chloride and 1000 parts of a 21% aqueous solution

_. . , Nitric acid solution became a gas mixture

Example 1 180 parts of ethylene, 30 parts of oxygen per hour

2.5 parts of PaUaaium (II) chloride to 10 and 30 parts of nitrogen oxide were passed through at 40.degree.

1000 parts of an aqueous 33% nitric acid - 2.1 parts of lithium chloride were added,

solution at 30 ⁰ C was added, and this overall durcli whereupon the deposited palladium rapidly

mixed, ethylene was dissolved in an hourly amount. After 3 hours the reaction contained

180 parts passed through as in Example 1. Then mix 105 parts of glyoxal, which has a selectivity of

0.65 parts of lithium chloride were added, and this corresponds to 15-85%. The palladium became the largest

Palladium precipitated beforehand was quickly dissolved, and part of it was precipitated by means of ethylene. The palladium was

on. The reaction was over after 1/2 hours. Filtered off, and the lithium chloride and the com-

36 parts of ethylene were absorbed, and the Reak- plexpalladiumsalzc were as in Example 1 again-

tion mixture contained 58 parts of glyoxal (75% of the recovered, and the glyoxal solution was also

theoretically calculated value). The palladium salts ao according to Example 1 concentrated,

were made by precipitation and ion exchange as in. .

Example 1 recovered. The glyoxal solution was Example 7

purified and concentrated, namely by distillation- A reaction tank equipped with a stirrer

tion, with an approximately 40% aqueous solution vessel containing 1000 parts of 20% nitric acid (in

revealed. as water) and 8 parts of palladium and 2.1 parts

_R. . Lithium chloride. The reaction vessel was also with

ti e 1 s ρ 1 e 1 j provided a dropping funnel, which is the same

It contained 9 parts of palladium (H) chloride to 1000 mixture. Through the reaction mixture

Dividing a 1% aqueous nitric acid solution was ethylene in an hourly amount of 180

added, and through this mixture 3 ° parts ethylene was passed with stirring. After 90 minutes

at 40 C in an hourly ». Amount of 180 parts, the reaction mixture was selected for 4 hours

passed through. Then, 2.1 parts of lithiumdene were continuously added in an hourly amount of

chloride added; the previously knocked down 500 parts deducted. The mixture in the drip tray

Palladium quickly dissolved. After 2 hours, the same amount of continuous

the reactor ended. 37.5 parts of ethylene were added to the reaction vessel. There were

len was absorbed, and the solution contained 69 parts 93 parts of ethylene absorbed. The removed remainder

Glyoxal (89% of the theoretical value). The palladium action mixture contained an average of 5.5 ° 0

dium and lithium salts were as in Be ^; game 1 glyoxal (80% of the theoretical value) and was

regained. The glyoxal solution was purified as in Example 1. The palladium and

Concentrated distillation. ^v 40 lilhrum chloride were reproduced according to Example 1

_. . , recovered and reused for the reaction.

Example 4

9 parts of palladium (II) chloride were converted into 1000 Example 8
Parts of a 21% aqueous nitric acid solution were added through a mixture of 2.44 parts of palla, and through the mixture were ethylene 45 dium (II) nitrate and 180 parts of a 20% at 35 ° C in an hourly amount of 180 parts Aqueous nitric acid solution was passed through it at 35 ° C. 4.2 parts of lithium chloride, ethylene were added in an hourly amount of 25 parts; the previously precipitated palladium was blown through as in Example 1. Then it was quickly dissolved. After 4 hours the reaction was 1.1 parts of lithium nitrate trihydrate and 0.62 part of NaN. 38.2 parts of ethylene trium nitrite were added; the previously precipitated sorbent and the reaction mixture contained 75 parts of palladium quickly dissolved. After 140 minutes glyoxal (95 %> of the theoretical value). The reaction was complete. As in Example 1, 6.4 parts of dium and lithium salts were absorbed, and the reaction mixture developed Eer recovered, and the glyoxal solution was kept 11.15 parts of glyoxal (84% of the theoretical value of Example 1 concentrated. 55 values). Most of the palladium hit. out of solution and was filtered off. Example 5 glyoxal solution was added dropwise for purification

There were 18 parts of palladium (II) chloride to 1000 with stirring liquid dimethylpolysiloxane at about

Parts of a 15% aqueous nitric acid solution 140 ° C and 15 to 30 Torr and added as purified

was added, and by this mixture ethylene 60 niges aqueous glyoxal was obtained as a distillate. the

at 50 ⁰ C in an hourly amount of 180 parts of palladium, lithium and sodium salts were from

passed through. Then 8.4 parts of lithium were added to the distillation residue by extraction

chloride added, followed by 2 parts of sodium nitric acid obtained,

nitrite, whereupon the precipitated palladium is. . . _

quickly dissolved. After 40 minutes the reaction was 65 B e ι s ρ 1 e 1 y

completed. 22 parts of ethylene were absorbed by a mixture of 2.44 parts of palla

and the reaction mixture contained 41 parts of glyoxal dium (II) nitrate and 180 parts of a 20% aqueous

C90 ° / o of the theoretical value). The palladium, gene nitric acid solution was at 35 ° C in ethylene

an hourly amount of 25 parts as in Example 1 passed. Then it was 0.38 parts Lithium chloride and 0.62 parts of sodium nitrite added; the previously deposited palladium dissolved up quickly. The reaction had ended after 210 minutes. 6.2 parts of ethylene were absorbed, and the R action mixture contained 11.1 parts of glyoxal (87 ° / o of the theoretical value). Most of the palladium precipitated out of the solution and was filtered out. The glyoxal solution was obtained by electroosmosis using a cell five compartments cleaned, with phosphate buffer solutions in the outer electrode compartments pH 7, in the inner compartments 1.0 n-sodium chloride and in the middle compartment the aqueous one Glyoxal solution were used. The divisions were alternately by anionic and cationic Membranes separated. Lithium cations accumulated in one of the inner compartments the other inner department accumulated complex palladium anions, with the middle department has been deionized. The lithium- and palladium-containing solutions obtained in this way could be used in the reaction to be led back.

Example 10

A mixture of 1.93 parts of palladium (II) sulphate and 180 parts of a 2% aqueous nitric acid solution was passed in at 35 ° C. in an hourly amount of 25 parts as in Example 1. Then, 0. 38 parts of lithium chloride and 0.62 part of sodium nitrite were added; the previously deposited palladium box was quickly dissolved. After 5 hours the reaction was complete. 6.05 parts of ethylene were absorbed and the mixture contained 9.8 parts of glyoxal (78 ⁰ O of the theoretical value). Most of the palladium precipitated out of the solution and was filtered off. The glyoxal solution was purified by passing it through a bed of activated carbon and through cationic and anionic exchange columns as in Example 1 and finally was concentrated by distillation under reduced pressure.

Hcis Di el 11

With a mixture of 1.6 parts of palladium (II) chloride and 180 parts of a 20% aqueous nitric acid solution was at 35 "C ethylene in an hourly amount of 25 parts as in Example 1 passed through. Then 1.1 parts of lithium nitrate and 0.62 parts of sodium nitrite were added; that Palladic who was previously depressed. quickly dissolved. The reaction had ended after 4.5 hours. 6.0 parts of ethylene were absorbed and the reaction mixture contained 11.35 parts of glyoxal (92% of the theoretical value). The palladium hit sicli for the most part settled out of the solution and was filtered off. The filtrate was made by adding calcium carbonate neutralized to pH 7, and the pitting precipitate of calcium salts of organic Acids and additional palladium were filtered off before the glycoxal solution was replaced by ion exchange resins and concentration by distillation under reduced pressure as in Example 1 was finally purified.

Example 12

By a mixture of 1.6 parts of palladium (II) chloride and 180 parts of a 20 »/ own aqueous nitric acid solution was at 35 ° C ethylene in a hourly amount of 25 parts as in Example 1 passed. Then there was 0.33 part of lithium carbunate and added 0.62 parts of sodium nitrite; the previously deposited palladium dissolved quickly on. The reaction was ended after 6.5 hours. 6.2 parts of ethylene were thereby withdrawn. and the reaction mixture. It contained 11.1 parts of glyoxal (87 ° / c of the theoretical value!,;. The solution was ao purified as in Example 11 by adding calcium carbonate and treating with ion exchange resins.

Example 13

as by a mixture of 1.6 parts of palladium (II) chloride and 180 parts of a 2O ° / o aqueous solution of nitric acid was passed at 35 to 40 C ethylene in an hourly amount of 25 parts as in Example. 1 Then there were 0.50 parts

Lithium nitrite added; the previously deposited palladium quickly dissolved. After 2.75 hours the reaction was over.

6.4 parts of ethylene were absorbed and the reaction mixture contained 11.9 parts of glyoxal (90 ⁶ / o of the theoretical value). Most of the CasPLÜadium precipitated out of the solution and was filtered off. The solution was purified as in Example 11 by adding calcium carbonate and treating with ion exclusion resins.

Claims (4)

Patent claims: 1. Process for the production of glyoxal by oxidation of ethylene with aqueous, 1 to 100 percent by weight nitric acid in the presence of palladium metal or a palladium compound, characterized, that the oxidation is additionally carried out in the presence of a water-soluble lithium salt. 2. The method according to claim 1, characterized in that the molar ratio of the lithium salt :: u Palladium in the reaction ratio is about 1: 1. 3. The method according to claim 1 and 2, characterized in that the reaction mixture also Contains sodium nitrite. 4. Verfaiircn according to claim 3, characterized in that that the molar ratio of sodium nilrite to lithium salt. in the reaction mixture is less than 1.