EP0713928B1 - Procédé et dispositif pour la préparation de nitrite de sodium - Google Patents

Procédé et dispositif pour la préparation de nitrite de sodium Download PDF

Info

Publication number
EP0713928B1
EP0713928B1 EP95118544A EP95118544A EP0713928B1 EP 0713928 B1 EP0713928 B1 EP 0713928B1 EP 95118544 A EP95118544 A EP 95118544A EP 95118544 A EP95118544 A EP 95118544A EP 0713928 B1 EP0713928 B1 EP 0713928B1
Authority
EP
European Patent Office
Prior art keywords
sodium nitrite
sodium
nitrate
solution
nitrite
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP95118544A
Other languages
German (de)
English (en)
Other versions
EP0713928A1 (fr
Inventor
Hans Jürgen Eisen
Christian Dr. Tragut
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Publication of EP0713928A1 publication Critical patent/EP0713928A1/fr
Application granted granted Critical
Publication of EP0713928B1 publication Critical patent/EP0713928B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/14—Alkali metal compounds

Definitions

  • the invention relates to a method and a device for producing sodium nitrite from solutions with sodium nitrate.
  • a method of this type is known from DE-A1 31 25 616.
  • the sodium nitrite solution (approx. 25-35% NaNO 2 , 2-6% NaNO 3 , small amounts of NaHCO 3 and Na 2 SO 3 , approx. 58-72%) originating from the alkaline scrubbing of nitrogen oxide gases of the low-pressure nitric acid plant.
  • H 2 O first filtered in a precoat filter to remove solid residues such as silica etc.
  • the filtered so-called raw solution is largely concentrated in evaporators upon crystallization of sodium nitrite.
  • the raw solution used in this process may only be evaporated to such an extent that the ratio of NaNO 2 / NaNO 3 in the salt-free mother liquor is not less than 3.
  • the specification of the low-nitrate sodium nitrite solution only allows a sodium nitrate content of max. 0.3%. This necessitates the production from washed sodium nitrite salt and condensed water; ie sodium nitrite must first be crystallized out, separated off by centrifuges and washed and finally dissolved again in water.
  • the invention is based, the aforementioned disadvantages to overcome and create a process that is significantly higher Allows yield of sodium nitrite at a lower cost.
  • US-A-2 273 799 describes the electrochemical reduction of sodium nitrate on a porous carbon cathode which is mixed with copper or silver as a catalyst material.
  • the method according to the invention differs essentially characterized by the known method that with him the filtered raw solution the electrochemical reduction (hereinafter referred to as ECR for short) introduced sodium nitrate to sodium nitrite on a cathode as described in claims 1 and 4, is subjected before the Sodium nitrite is separated off.
  • ECR electrochemical reduction
  • the filtered crude sodium nitrite solution cooled to -10 ° C for the electrolysis.
  • the pH value should be carefully lowered slightly, just enough that none Nitrogen development occurs. This involves sodium bicarbonate and sodium carbonate converted into sodium nitrate.
  • the electrolysis takes place in such a way that at the cathode of an electrolysis cell Nitrate ions can be selectively reduced to nitrite ions.
  • the cell By construction the cell must be ensured that the in the saline existing nitrite ions on the anode are not oxidized to nitrate will.
  • a reduction of the nitrate to lower oxidation levels of the Nitrogen than in the nitrite must be chosen by choosing the appropriate cathode as well can be avoided by suitable electrolysis conditions.
  • the anodic oxidation of the nitrite can be carried out according to an embodiment of the Invention by means of the separation of anode and cathode space a cation exchange membrane or a diaphragm avoided will.
  • the aqueous solution is in the anode compartment a mineral acid with a typical concentration of 2% to 5%, preferably sulfuric or nitric acid, which is sufficiently high Guaranteed conductivity of the anolyte.
  • Water is added to the anode Reacted oxygen and hydronium ions through the diaphragm, or the cation exchange membrane get into the cathode compartment can.
  • the anode itself is realized in the usual way, e.g. B. as an expanded metal electrode with a low oxygen overvoltage.
  • the electrolysis can also be performed in an undivided cell. Then through Selection of the electrode material and the electrolysis conditions ensured be that there is no oxidation of the nitrite at the anode can, for example by iron anodes in alkaline electrolyte solution.
  • the cathode compartment is made up of the sodium nitrite to be reacted and saline solution containing sodium nitrate.
  • the nitrate ion is reduced to nitrite, with consumption of hydronium ions creates water.
  • This cathode consists of one porous silver electrode with large surface area and high catalytic activity, which is a selective reduction of nitrate to nitrite at a high Current density allows. she consists from a bed of an electrical contact Metal powder or from a sintered metal plate.
  • Metal powder like Sintered metal plates can also be removed by alkaline leaching of a silver-aluminum or silver-alkaline earth alloy according to the way of producing one Raney catalyst can be obtained. This alloy is made before Leaching out by grinding or producing a porous sintered metal plate brought into the appropriate form.
  • the electrode is removed from the nitrite / nitrate solution flows through.
  • the flow can be perpendicular or parallel to the current direction take place and ensures a sufficiently high mass transfer down to the lowest nitrate concentrations on the electrode surface.
  • the electrolysis can be carried out in one step be that the nitrate content of the converted catholyte of the required Specification of low nitrate solution corresponds.
  • the method according to the invention is not only suitable for improvement of the known process for the production of sodium nitrite, but also for the production of nitrite from nitrate solutions, for example from natural saltpetre can be obtained.
  • the advantages of the method according to the invention are on the one hand see that the nitrite yield is maximum. For one thing, it stays in the Obtain the raw sodium nitrite delivered almost quantitatively to others is caused by the electrochemical reaction (ECR) of sodium nitrate the equivalent amount of sodium nitrite additionally generated. Thereby increases the available amount of sodium nitrite based on the nitrogen used considerable compared to the known method, and by at least 30%.
  • ECR electrochemical reaction
  • nitrate-free (nitrate-free) obtained with the process according to the invention Sodium nitrite solution can be added directly to 40% sodium nitrite solution and sodium nitrite salt can be processed further. This can be done in one go happen in such a way that in a sufficiently high concentration level evaporated (duplexes, triplexes) sodium nitrite solution and with solution from the electrolysis to the desired sodium nitrite concentration is set and the remaining sodium nitrite solution in the crystallizer is concentrated to salt. Crystallization, separation, drying, cooling and conditioning of the sodium nitrite salt are done in terms of process engineering as with the known method.
  • a block diagram that uses the flow of such a procedure the invention is shown in the drawing.
  • a raw sodium nitrite solution at the point marked with arrow 1, which still contains 2 to 6% by weight of sodium nitrate, the filtration 2 fed.
  • the filtration 2 After the filtration, part of this solution becomes directly the Electrolysis 3 supplied according to the invention.
  • the resulting sodium nitrite solution is partially evaporated in a concentration level 4 and then with a branched off via line 5 after electrolysis 3 Stream mixed in a mixer 6.
  • the resulting low-nitrite solution (S) with a content of 39 to 41 wt .-% sodium nitrite subtracted at 7.
  • Part of the resulting in concentration level 4 Solution is fed via line 8 to a crystallization stage 9.
  • the resulting salt is separated in the separation stage 10.
  • the remaining mother liquor is via line 11 in the crystallization stage 9 returned.
  • the sodium nitrite salt separated in the separation stage 10 is dried in drying stage 12, cooled and conditioned and subtracted at 13.
  • Part of the filtered raw solution is fed via line 14 to a further concentration stage 15.
  • the resulting nitrite solution which still has a sodium nitrate content of 6 to 10 wt .-%, is in a mixer 16 with a subset the crude nitrite solution drawn off after the filtration 2 through line 17 mixed.
  • the resulting nitrite solution has a sodium nitrite content from 39 to 41% by weight and a sodium nitrate content of 2 to 4 % By weight. It is deducted at 21.
  • nitrite solution Part of that at the concentration level 4 resulting nitrite solution is via line 19 to a mixer 20 fed where they are via line 18 with a portion of filtered crude solution is united. This creates a nitrite solution with 39 to 41 % By weight sodium nitrite and 1 to 2% by weight sodium nitrate, which was subtracted at 21 becomes.

Claims (4)

  1. Procédé de fabrication de nitrite de sodium à partir de solutions, avec du nitrate de sodium, par électrolyse, dans une cellule dans laquelle la solution contenant le nitrate de sodium a été introduite au moyen d'une cathode qui est constituée d'une électrode poreuse ayant une surface de grande aire et une activité catalytique élevée, caractérisé par le fait que la cathode est constituée d'une masse en vrac pourvue d'un contact électrique ou bien d'une plaque de métal fritté constituée d'une poudre de métal argentique, obtenue par lixiviation alcaline d'un alliage argent-aluminium ou argent-alcalino-terreux.
  2. Procédé selon la revendication 1, caractérisé par le fait que le matériau du produit en vrac ou de la plaque en métal fritté est obtenu suivant le procédé de Raney.
  3. Procédé selon la revendication 2, caractérisé par le fait que l'alliage est mis à la forme correspondante avant lixiviation par broyage ou fabrication d'une plaque en métal fritté.
  4. Dispositif de mise en oeuvre du procédé selon l'une des revendications 1 à 3, dans lequel la cellule est pourvue, pour réaliser l'électrolyse, d'une cathode qui est constituée d'une électrode poreuse ayant une surface de grande aire et d'une activité catalytique élevée, caractérisé par le fait que la cathode est constituée d'une masse en vrac ou d'une plaque de métal frittée, qui a été fabriquée par lixiviation alcaline d'un alliage argent-aluminium ou bien d'un alliage argent-alcalino-terreux.
EP95118544A 1994-11-24 1995-11-24 Procédé et dispositif pour la préparation de nitrite de sodium Expired - Lifetime EP0713928B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4441937A DE4441937A1 (de) 1994-11-24 1994-11-24 Verfahren und Vorrichtung zur Herstellung von Natriumnitrit
DE4441937 1994-11-24

Publications (2)

Publication Number Publication Date
EP0713928A1 EP0713928A1 (fr) 1996-05-29
EP0713928B1 true EP0713928B1 (fr) 1998-06-17

Family

ID=6534101

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95118544A Expired - Lifetime EP0713928B1 (fr) 1994-11-24 1995-11-24 Procédé et dispositif pour la préparation de nitrite de sodium

Country Status (2)

Country Link
EP (1) EP0713928B1 (fr)
DE (2) DE4441937A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020198726A1 (fr) * 2019-03-28 2020-10-01 Kemin Industries, Inc. Compositions d'extraits à base de plantes à réduction électrochimique pour la cuisson de la viande et procédés associés

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE174737C (fr) *
US2273799A (en) * 1938-12-17 1942-02-17 Nat Carbon Co Inc Process for electrolytic reduction
GB2038872B (en) * 1978-10-06 1983-01-26 Asahi Chemical Ind Electrolytic process for preparing nitrites
DE3125616C2 (de) 1980-07-05 1994-05-11 Basf Ag Verfahren zur Herstellung von festen Alkalinitriten
DE3729669A1 (de) * 1987-09-04 1989-03-16 Basf Ag Verfahren zur herstellung von alkalimetallnitraten

Also Published As

Publication number Publication date
DE4441937A1 (de) 1996-05-30
EP0713928A1 (fr) 1996-05-29
DE59502587D1 (de) 1998-07-23

Similar Documents

Publication Publication Date Title
DE3622536C2 (fr)
EP0012215B1 (fr) Sel de choline et d'acide hydroxy-2-butane sulfonique et son utilisation comme sel conducteur
DE2808424A1 (de) Verfahren zur gewinnung von kristallen von natriumcarbonatmonohydrat
DE60209109T2 (de) Verfahren zur reinigung einer redox-mediator enthaltenden lösung vor dessen elektrolytischen regenerierung
EP0713928B1 (fr) Procédé et dispositif pour la préparation de nitrite de sodium
DE2753233A1 (de) Verfahren zur herstellung von chlor und natriumcarbonatmonohydrat
DE2240731A1 (de) Verfahren zur herstellung von glyoxylsaeure
EP0721017B1 (fr) Procédé de préparation de solutions pures de tungstène et de molybdène
EP0108968A1 (fr) Procédé pour la production d'oxyde d'aluminium actif
DE102021123151A1 (de) Verfahren und Anlage zur Rückgewinnung von Metallen aus schwarzer Masse
DE2757069C3 (de) Verfahren zur Abtrennung von Gallium aus den bei der Herstellung von Tonerde aus siliziumreichen, aluminiumhaltigen Erzen, insbesondere Nephelinen, bei einer zweistufigen Carbonisierung anfallenden Produkten
EP0138801A1 (fr) Procédé d'affinage électrolytique de l'argent
DE19506242C2 (de) Verfahren zur direkten elektrochemischen Oxidation von sulfithaltigen Lösungen, insbesondere Abwässern aus Gasreinigungsanlagen
DE2837313A1 (de) Verfahren zur elektrolyse waessriger alkalihalogenid-loesungen
DE1266292B (de) Verfahren zur Herstellung von Ammoniumparawolframat durch anodische Oxydation von Wolframabfaellen
DE19532784C2 (de) Elektrolyseverfahren zum Regenerieren verbrauchter Eisen-III-chlorid- oder Eisen-III-sulfat-Ätzlösungen
DD297141A5 (de) Verfahren zur herstellung einer natriumhydroxid-lauge
EP0433750B1 (fr) Procédé de préparation d'acide chromique
EP0160171B1 (fr) Procédé de préparation de solutions salines de manganèse (II) contenant un sel d'ammonium
DE3104578A1 (de) Verfahren zum entfernen von metallen aus metallsalzloesungen
DD297140A5 (de) Verfahren zur herstellung einer natriumhydroxid-lauge
AT409764B (de) Verfahren zur oxidation von vanadium
DE1907523C3 (de) Verfahren zur extraktiven Elektrolyse von Zink aus seinen schwefelsauren Lösungen
DD257361A3 (de) Elektrochemisches kreislaufverfahren zum aetzen von eisen und seinen legierungen
DE3347100A1 (de) Einsatz eines schwingreaktors als elektrolysezelle

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE FR GB LI NL

17P Request for examination filed

Effective date: 19960717

17Q First examination report despatched

Effective date: 19970121

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH DE FR GB LI NL

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: SCHMAUDER & WANN PATENTANWALTSBUERO, INHABER KLAUS

Ref country code: CH

Ref legal event code: EP

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19980701

REF Corresponds to:

Ref document number: 59502587

Country of ref document: DE

Date of ref document: 19980723

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20011017

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20011024

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20011029

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20011116

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20011121

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20011220

Year of fee payment: 7

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021124

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021130

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021130

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 20021213

BERE Be: lapsed

Owner name: *BASF A.G.

Effective date: 20021130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030601

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030731

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20030601

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST