EP1483204A1 - Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore - Google Patents

Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore

Info

Publication number
EP1483204A1
EP1483204A1 EP03702616A EP03702616A EP1483204A1 EP 1483204 A1 EP1483204 A1 EP 1483204A1 EP 03702616 A EP03702616 A EP 03702616A EP 03702616 A EP03702616 A EP 03702616A EP 1483204 A1 EP1483204 A1 EP 1483204A1
Authority
EP
European Patent Office
Prior art keywords
extraction
chlor
wastewater
waste water
solution
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.)
Withdrawn
Application number
EP03702616A
Other languages
German (de)
English (en)
Inventor
Jürgen HEUSER
Werner Verhoeven
Domien Sluyts
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.)
Covestro Deutschland AG
Original Assignee
Bayer MaterialScience AG
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 Bayer MaterialScience AG filed Critical Bayer MaterialScience AG
Publication of EP1483204A1 publication Critical patent/EP1483204A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/04Chlorides
    • C01D3/06Preparation by working up brines; seawater or spent lyes
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01DCOMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D3/00Halides of sodium, potassium or alkali metals in general
    • C01D3/14Purification
    • C01D3/18Purification with selective solvents
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/20Treatment of water, waste water, or sewage by degassing, i.e. liberation of dissolved gases
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/26Treatment of water, waste water, or sewage by extraction
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/66Treatment of water, waste water, or sewage by neutralisation; pH adjustment
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/34Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
    • C02F2103/36Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
    • C02F2103/38Polymers
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00Multistage treatment of water, waste water or sewage

Definitions

  • the present invention relates to a process for the treatment of saline wastewater, characterized in that an aqueous saline solution is obtained by a certain sequence of acidification, extraction, alkalization and stripping steps, which can be used directly in chlor-alkali electrolysis ,
  • Saline wastewater is produced in many chemical processes.
  • phase interface process for the production of polycarbonate or the production of diphenyl carbonate also in the phase interface process and many other chemical reactions in which sodium chloride is formed directly or indirectly (see, for example, Schnell, “Chemistry and Physics of Polycarbonates”, polymer
  • waste water could be better disposed of.
  • a possible option would be the use of such waste water in chlor-alkali electrolysis. Firstly, this would not pollute the environment with salt, secondly, resources would be saved and raw material costs would be saved. For use in chlor-alkali electrolysis, however, only waste water is considered which contains chlorides as anions practically exclusively. Therefore, wastewater, which still contains other anions and organic impurities, must be treated accordingly beforehand.
  • wastewater generated in the production of polycarbonate or diaryl carbonate contains carbonate from phosgene hydrolysis in addition to saline concentrations of 2 to 20%.
  • organic contaminants are also present. So there are still residues of phenols or bisphenols, catalyst and solvent. All these
  • Impurities would have to be reduced to a minimum to enable use in chlor-alkali electrolysis.
  • reaction salts containing saline such as are obtained, for example, from the interfacial processes for polycarbonate or diphenyl carbonate synthesis, can be worked up by means of reactive extraction after acidification in such a way that a solution suitable for introduction into the environment is obtained becomes. It is also pointed out that this solution can be used in chlor-alkali electrolysis after appropriate concentration. However, the process described there is not suitable for directly delivering a solution suitable for use in chlor-alkali electrolysis. The residual organic load still present according to this process would also be concentrated if it was concentrated, making the solution unsuitable for chlor-alkali electrolysis.
  • saline process wastewater can be treated in such a way that the remaining saline solution can be used directly in the chlor-alkali electrolysis by using the process wastewater acidified with HCI and then degassed with an organic solvent, the aqueous phase alkalized and stripped with steam.
  • the salt solution obtained can be used directly in the electrolysis, a concentration is not necessary. In the case of membrane electrolysis, salt cleaning is no longer necessary and the water can be recycled.
  • the extracted phenols can be used again as raw materials in the synthesis.
  • Reactive extraction are operated. 7.
  • the COD value achieved in the treated wastewater is below 30 ppm and thus below the application limit of the COD process. The value is therefore not exactly determinable but very low.
  • the wastewater from the reaction is first with HCl, preferably with commercially available 37% aqueous acid, up to a pH of 1-5, preferably from 3 to 4, very particularly preferably 3 acidified.
  • the carbonates are thus converted into carbonic acid, which escapes as a gas.
  • the carbonic acid can possibly be recovered in order to convert it to CO in a reformer.
  • phenolic anions are converted into the corresponding free phenolic compounds.
  • Apolar organic solvents such as e.g. Methylene chloride, chlorobenzene or a mixture of these two, MIBK (methyl isobutyl ketone) or ether, preferably methylene chloride, chlorobenzene or a mixture of these two, can be used.
  • MIBK methyl isobutyl ketone
  • ether preferably methylene chloride, chlorobenzene or a mixture of these two
  • Base preferably long chain tertiary amines such as e.g. Use alamin or tri-iso-octyl-amine, especially tri-iso-octyl-amine, as the reactive extractant, dissolved in inert apolar organic solvents such as petroleum fractions, e.g. Shell-Sol AB.
  • inert apolar organic solvents such as petroleum fractions, e.g. Shell-Sol AB.
  • inert organic solvents is preferred. This removes the phenolic compounds and other organic compounds from the aqueous solution. This extraction takes place in several, preferably 4-10 stages.
  • Mixer-settlers or extraction columns, preferably extraction columns, particularly preferably pulsed filling or sieve plate columns, can be used for this purpose, see FIG. z. B. Perry's Chemical Engineering Handbook, Mc Graw Hill, New York,
  • Sodium hydroxide solution in a concentration of 1-30%, preferably 5 to 20% NaOH, re-extracted.
  • the alkaline aqueous phase is used in a significant deficit as an extractant in order to achieve the highest possible phenolate concentrations in the alkaline aqueous phase.
  • a ratio of aqueous sodium hydroxide solution to organic phase of about 1:50 to 1: 1000, preferably 1: 400 to 1: 1000, would suffice. The exact However, ratios depend on the concentration of phenol in the organic phase to be worked up, since it is a reactive extraction in which approx.
  • Partial flow to mass flow of the extracted organic phase now corresponds to the above-mentioned ratio.
  • the aqueous extract obtained in this way can be treated further in order to recover phenols.
  • a preferred procedure is that the re-extraction with sodium hydroxide solution is carried out in two stages.
  • extralation is carried out with an aqueous sodium hydroxide solution / phenolate solution, which is formed from the partial stream removed in the second extraction stage with the addition of additional NaOH to restore the concentration of 1-30%, preferably 5 to 20%, as described above.
  • the partial stream obtained in this stage is fed directly to the phenol recovery and a corresponding amount of lye from the second stage as fresh lye, with the addition of additional NaOH to restore the concentration of 1-30%, preferably 5 to 20% NaOH, again.
  • a concentration of 1-30%, preferably 5 to 20% NaOH is extracted with NaOH, as described above, the partial stream removed being replaced by fresh liquor and this partial stream, with the addition of additional NaOH, to restore the concentration of 1-30 %, preferably 5 to 20% NaOH, is added as a fresh extractant to the first stage.
  • a concentrated aqueous-alkaline solution of the phenolates is obtained, from which simply by neutralizing with
  • HCI two phases arise, which are separated in a simple separation container can. In this way you get an upper phase, which contains about 90% of the phenane amount, and which can either be used again in a synthesis (eg DPC) or otherwise eliminated.
  • the other phase consists of an aqueous saline solution slightly contaminated with phenol and is returned to the reaction wastewater to be processed.
  • the content of phenolic compounds in the organic phase is reduced to below 1 ppm by this re-extraction.
  • the organic phase thus freed from phenolic compounds is returned to the extraction of the reaction waste water as the extraction agent.
  • the two-stage re-extraction can be designed, for example, in the form of a countercurrent extraction. These re-extractions are preferably carried out in a mixer-settler, e.g. as described in Perry's Chemical Engineering Handbook, Mc Graw Hill, New York, 1999, 15-22 to 15-29.
  • the extracted saline process wastewater largely freed from phenolic and other organic compounds, is now alkalized with aqueous sodium hydroxide solution of any concentration, for example 1-50% NaOH, to a pH of 7-13, preferably 8-12, and with steam at 1- 4, preferably 2-3, particularly preferably 2.5 bar in a stripping column, see. e.g. "Azeotropic Distillation" in Perry's Chemical
  • the amount of water vapor is related to the amount of solution to be stripped, such as 1-5, preferably 2-4, particularly preferably 3-3.5 to 100.
  • both the catalyst and the residual solvent are removed.
  • the top gases of the column therefore contain the catalyst and residual solvent, are condensed and can be returned to the synthesis reaction.
  • the bottom product is a pure saline solution, which can now be used directly in chlor-alkali electrolysis.
  • the content of residual organics in the saline solution thus prepared is ⁇ 0.3, preferably ⁇ 0.1 ppm, bisphenols and catalyst residues are no longer detectable and the residual content of organic solvents is ⁇ lppm, preferably ⁇ 0.1 ppm.
  • Wastewater from diphenyl carbonate production contains 200 ppm phenol, 30 ppm ethyl piperidine (EPP), 2 ppm diphenyl carbonate and 0.25% sodium carbonate.
  • EPP ethyl piperidine
  • the phenol concentration in the wastewater after the extraction column is ⁇ 200 ppb.
  • the ratio of wastewater to extractant (methylene chloride) is 2: 1.
  • the COD is 28 ppm and can therefore no longer be measured reproducibly because the sensitivity of the method is insufficient.
  • the high NaCl content of the solution also leads to increased measured values so that the actual COD is still significantly lower.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Physical Water Treatments (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Degasification And Air Bubble Elimination (AREA)
  • Extraction Or Liquid Replacement (AREA)

Abstract

La présente invention concerne un procédé de préparation d'eaux résiduaires contenant du chlorure de sodium. Ce procédé est caractérisé en ce qu'une séquence déterminée d'étapes d'acidification, d'extraction, d'alcalinisation et de stripage permet d'obtenir une solution aqueuse de chlorure de sodium directement utilisable dans l'électrolyse à l'alcali et au chlore.
EP03702616A 2002-02-22 2003-02-10 Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore Withdrawn EP1483204A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10207442A DE10207442A1 (de) 2002-02-22 2002-02-22 Aufbereitung von Kochsalz enthaltenden Abwässern zum Einsatz in der Chlor-Alkali-Elektrolyse
DE10207442 2002-02-22
PCT/EP2003/001282 WO2003070639A1 (fr) 2002-02-22 2003-02-10 Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore

Publications (1)

Publication Number Publication Date
EP1483204A1 true EP1483204A1 (fr) 2004-12-08

Family

ID=27740305

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03702616A Withdrawn EP1483204A1 (fr) 2002-02-22 2003-02-10 Preparation d'eaux residuaires contenant du chlorure de sodium et destinees a etre utilisees dans l'electrolyse a l'alcali et au chlore

Country Status (8)

Country Link
US (1) US20050115901A1 (fr)
EP (1) EP1483204A1 (fr)
JP (1) JP2005517624A (fr)
CN (1) CN1646429A (fr)
AU (1) AU2003205750A1 (fr)
DE (1) DE10207442A1 (fr)
TW (1) TW200306952A (fr)
WO (1) WO2003070639A1 (fr)

Families Citing this family (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1687248B1 (fr) * 2003-11-20 2011-06-01 SOLVAY (Société Anonyme) Procédé de production de dichloropropanol à partir de glycérol et d'un agent chlorant en la présence d'un catalyseur choisit parmi l' acide adipique ou glutarique
KR20080037618A (ko) 2005-05-20 2008-04-30 솔베이(소시에떼아노님) 폴리히드록실화 지방족 탄화수소 및 염소화제 간의 반응에의한 클로로히드린 제조 방법
EP1885671A1 (fr) * 2005-05-20 2008-02-13 Solvay SA Procede de fabrication d'une chlorhydrine au depart d'un hydrocarbure aliphatique poly hydroxyle
DE102005047460A1 (de) * 2005-09-30 2007-04-05 Basf Ag Verfahren zur Behandlung von Abwasser aus Aldolisierungsverfahren
EP2043984A1 (fr) 2006-06-14 2009-04-08 Solvay S.A. Produit à base de glycérol brut, procédé pour sa purification et son utilisation dans la fabrication de dichloropropanol
DE102006041465A1 (de) * 2006-09-02 2008-03-06 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
US20100032617A1 (en) * 2007-02-20 2010-02-11 Solvay (Societe Anonyme) Process for manufacturing epichlorohydrin
FR2913684B1 (fr) * 2007-03-14 2012-09-14 Solvay Procede de fabrication de dichloropropanol
TW200911693A (en) * 2007-06-12 2009-03-16 Solvay Aqueous composition containing a salt, manufacturing process and use
TWI500609B (zh) * 2007-06-12 2015-09-21 Solvay 含有環氧氯丙烷的產品,其製備及其不同應用中的用途
FR2918058A1 (fr) * 2007-06-28 2009-01-02 Solvay Produit a base de glycerol, procede pour sa purification et son utilisation dans la fabrication de dichloropropanol
JP2010537799A (ja) * 2007-08-23 2010-12-09 ダウ グローバル テクノロジーズ インコーポレイティド ブライン精製
JP2011502032A (ja) * 2007-10-02 2011-01-20 ソルヴェイ(ソシエテ アノニム) 容器の耐腐食性を向上させるためのケイ素を含有する組成物の使用
DE102007058701A1 (de) * 2007-12-06 2009-06-10 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
FR2925045B1 (fr) * 2007-12-17 2012-02-24 Solvay Produit a base de glycerol, procede pour son obtention et son utilisation dans la fabrication de dichloropropanol
TWI478875B (zh) * 2008-01-31 2015-04-01 Solvay 使水性組成物中之有機物質降解之方法
DE102008038031A1 (de) 2008-08-16 2010-02-18 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonaten
EP2090605B1 (fr) 2008-02-13 2011-07-13 Bayer MaterialScience AG Procédé de fabrication de polycarbonates
DE102008011473A1 (de) 2008-02-27 2009-09-03 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
CN101980995B (zh) * 2008-04-03 2014-06-18 索尔维公司 包含甘油的组合物、获得该组合物的方法以及它们在二氯丙醇生产中的用途
JP2009285533A (ja) * 2008-05-27 2009-12-10 Teijin Chem Ltd 排水の処理方法
FR2935968B1 (fr) * 2008-09-12 2010-09-10 Solvay Procede pour la purification de chlorure d'hydrogene
FR2939434B1 (fr) * 2008-12-08 2012-05-18 Solvay Procede de traitement de glycerol.
DE102009017862A1 (de) * 2009-04-17 2010-10-21 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
DE102009023940A1 (de) 2009-06-04 2010-12-09 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
DE102009032020A1 (de) 2009-07-07 2011-01-13 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
WO2011032311A1 (fr) * 2009-09-17 2011-03-24 宁波万华聚氨酯有限公司 Procédé pour traiter de l'eau salée de déchets produite dans un processus de production de diisocyanate de diphénylméthane (mdi)
US9169131B1 (en) * 2010-04-21 2015-10-27 Trinity Manufacturing, Inc. System and process for removing total organic carbons from a brine waste stream
FR2964096A1 (fr) * 2010-08-27 2012-03-02 Solvay Procede d'epuration d'une saumure
JP6049087B2 (ja) 2010-09-30 2016-12-21 ソルヴェイ(ソシエテ アノニム) 天然起源のエピクロロヒドリンの誘導体
CN104003424B (zh) * 2014-06-09 2017-03-01 国药集团化学试剂有限公司 一种降低氯化钠或氯化钾中溴离子和碘离子含量的方法
CN104710067B (zh) * 2015-02-16 2016-01-20 聊城鲁西聚碳酸酯有限公司 一种聚碳酸酯生产废水处理的系统与处理工艺
WO2018029200A1 (fr) 2016-08-10 2018-02-15 Covestro Deutschland Ag Procédé de purification électrochimique de solutions de traitement contenant des chlorures
CN109231544A (zh) * 2018-09-25 2019-01-18 青岛科技大学 一种聚碳酸酯生产过程中产生的废盐水的处理方法
CN109354261B (zh) * 2018-12-10 2022-02-15 浙江普洛家园药业有限公司 一种对羟基苯甘氨酸合成工业废水的处理工艺
CN110270130B (zh) * 2019-07-21 2021-06-25 河南师范大学 基于利多卡因的疏水性低共熔溶剂及其制备方法和应用
CN111453905A (zh) * 2020-03-20 2020-07-28 鲁西化工集团股份有限公司氯碱化工分公司 一种再生酸碱废水资源化处置工艺及其装置

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2733981A (en) * 1956-02-07 Salt recovery process
GB1053030A (fr) * 1963-03-21
US3259567A (en) * 1964-01-31 1966-07-05 Gen Mills Inc Method and apparatus for treatment of detergent-laden wastes
JP2681682B2 (ja) * 1989-03-14 1997-11-26 出光石油化学株式会社 分岐状ポリカーボネートの製造方法
ES2037904T3 (es) * 1989-05-09 1993-07-01 Bayer Antwerpen N.V. Procedimiento para la extraccion de nitrato y contaminantes organicos de efluentes.
USH1467H (en) * 1993-11-16 1995-08-01 Shell Oil Company Detergent formulations containing a surface active composition containing a nonionic surfactant component and a secondary alkyl sulfate anionic surfactant component
DE19510063A1 (de) * 1995-03-20 1996-09-26 Bayer Antwerpen Nv Verfahren zur Reinigung von phenolhaltigem Prozeßabwasser
DE19823155A1 (de) * 1998-05-23 1999-11-25 Henkel Kgaa Verfahren zur Verringerung des Formaldehydgehalts in sauren Lösungen von Melamin-Formaldehydharzen
US6340736B1 (en) * 1999-11-29 2002-01-22 General Electric Company Method and apparatus for the production of polycarbonates with brine recycling

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO03070639A1 *

Also Published As

Publication number Publication date
TW200306952A (en) 2003-12-01
US20050115901A1 (en) 2005-06-02
AU2003205750A1 (en) 2003-09-09
JP2005517624A (ja) 2005-06-16
WO2003070639A1 (fr) 2003-08-28
DE10207442A1 (de) 2003-09-11
CN1646429A (zh) 2005-07-27

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