SA99200181B1 - A method for cleaning up excess water resulting from the preparation of ALCOHOLS - Google Patents

Abstract

Abstract: This invention relates to a method for cleaning up the excess water fractions resulting from the preparation of alcohols. The preparation of the alcohols involves an aldolization reaction which is followed by a hydrogenation reaction after which the alcohol is distilled through a distillation process. The fractions of excess water include three parts of special steps during the preparation of alcohol. The method for cleaning the excess water portions involves (a) combining two of the three portions and adjusting them to a certain pH of the union, (v) making contact of at least one of the portions with an amalgamation filter, and (c) extracting the mixture of the three portions.

Description

A method for cleaning the excess water resulting from the preparation of complete alcohols, Cha oll. The product of condensation of acetaldehyds to similar or dissimilar aldehydes or ketones groups; or through different aldolization of aldehydes and ketones groups. Which is followed by a hydrogenation process (hydrogen treatment). (hydrogenation) and the term aldol treatment is used to include the addition of aldol and the condensation of aldol (Cs) in turn means the condensation of two parts of aldehydes in such a way that the oxygen of one part of them interacts with the hydrogen of the other part forming a hydroxyl group: 004:0 with 0 The simultaneous formation of a new bond between the two carbon atoms” and throws the water out.” gladly aldolization aldolization describes the base- or acid-catalyzed addition of active methylene groups to the carbonyl groups of aldehydes carbonyl or “al all” With the formation of beta-hydroxy-carbonyl compounds. And if the addition of aldolization is followed by removal of water; Which occurs in it and is counterproductive when using VO catalysts from ¢ acid and that is called aldolization. The condensation products of aldolization are alpha and beta carbonyl compounds a, B-unsaturated carbonyl. It should be noted that the aldolization of two parts of the same aldehyde or the same ketone is of particular interest. Load interactions of this type are used industrially. An example of industrial application is the preparation of =V ethyl hexanol 2-ethyl hexanol “Yo” which represents the most important industrial alcohols after low alcohols “methanol to butanol; This is done by aldol treatment of n-butyraldehyde and then successive hydrogenation. The phthalic esters of a compound = 2-ethyl hexanol are widely used in the form of plasticizers for plastics (Lau).

. As for the preparation of alcohols, which is accompanied by the introduction of the aldolization step, “aldehydes are first reacted; starting material; in the presence of aqueous solutions; basicity; During the process of condensation of the aldol in order to form alpha and beta aldehyde a, B-unsaturated aldehyde unsaturated ¢ and during the preparation of the aforementioned compound – Y ethyl hexanol 2-ethyl hexanol » Jelis poly-butyer aldehyde is based on it 2-ethyl hexanol to form -Y-ethylhexenal 2-ethyl hexenal under the action of an aqueous solution of sodium hydroxide; For example. Then, the organic shall comprising Lins Wl unsaturated a, B-unsaturated aldehyde is separated from the aqueous phase containing the catalyst. After this, the organic phase was washed with water and the unsaturated alpha- and beta-aldehyde was hydrogenated to obtain the desired alcohol; Ve, and in the case of the compound ?- 2-ethyl hexenal, to obtain ?- Jf 2-ethyl hexanol. The crude alcohol obtained by a process of distillation is then purified and the remainder of the distillation is subjected to washing again with water. Under the aldolization process and the subsequent hydrogenation process; Three parts of excess water are produced. It is (1) 0 the aqueous phase containing the catalyst and resulting from Jolin treated with aldol. ela (Y) leaching resulting from the purification process WY and beta aldehyde a B-unsaturated aldehyde Unsaturated and produced during the aldol treatment process and (©) the wash water resulting from cleaning the remaining part of the distillation process of alcohol Y. These parts of the excess water include a substance dissolved in eld and other insoluble in water; as well as by-products an emulsion, which can be formed in the stages of a single process, in addition to unreacted starting materials and very small amounts of the products formed. Unsaturated Yo-beta aldehydes are associated with the aldolization process and the alcohols formed from them after hydrogenation.These products are present only in very small quantities, especially for the by-products of the aldolization process and the hydrogenation process, which are present in the total amount of excess water.

£ aldol treatment of poly-butyraldehyde; compound ?- ethylhexinal; For example; by 70,7 wt. max.; Based on the total amount of all organic compounds present in the excess water; any ; the amount of unreacted starting materials; The by-products of the aldol treatment process and the hydrogenation process, as well as the products of aldol treatment and hydrogenation °. or branched containing the same number of carbon atoms as in an aldehyde; Unbranched or branched alcohols contain one carbon atom more than the aldehyde used » cyclic esters (lactones) contain the same

0 the number of carbon atoms as in an aldehyde ¢ carboxylic acids ; It is present in the form of ¢ salts, especially alkali metal salts; have the same number of carbon atoms as the aldehyde and the corresponding free carboxylic acids; Aldehydes, which are produced by hydrogenation WY and unsaturated beta aldehyde through aldol treatment » cyclic lactones and cyclic diols

1 includes; More carbon atoms than the desired alcohol resulting from the aldolization and hydrogenation process. Carboxylic esters resulting from the desired alcohol. and the corresponding carboxylic acid and carboxylic esters resulting from the desired alcohol and the carboxylic acid having the same number of carbons as the starting aldehyde.

Y. In addition; The following may be present in very small quantities as by-products; disproportionately branched alcohols; aldehydes; ethers Lactones and acids have either 1 or 2 carbon atoms less or 1 to ; more carbon atoms than the desired alcohol; And resulting from the process of aldol treatment and dependent hydrogenation. In addition, the excess water may also contain hydrogenation products of the by-products

Yo produced from the reaction of aldol treatment as well as condensate products with a high boiling point.

And in the case of preparing ?- ethyl hexanol by aldol treatment of a poly-butyer aldehyde compound in the presence of sodium hydroxide solution followed by hydrogenation; The amount will be included

° Total excess water; eg Jeo : n-butanal ¢ I-butanal ¢ n-butanol ; isobutanol butanol « 7- methylbutanol 2-methylbutanol ¢ n-butyric acid ¢ sodium butyrate » 4-heptanol —Y » 4-heptanol methyl-;- hepnaphaelson —Y » 3-methyl-4-heptanone © methyl —¢— heptanol -1 + 3-methyl-4-heptanol methyl -;- methylpentanal =Y » 2-ethyl-4-methyl-pentanal Ethyl-;- methylpentafsol-1 » 2-ethyl-4-methylpentanol ylhemexanal Jf -7 ». 2-ethylhexanal ~Y « 2-ethylhexenal ethylhex-?-enol 2-ethylhex-3-enol ¢ ?-ethylhexanol -1 « 2-ethylhexanol aqyl Ju ua butyrate —Y « 2-ethylhexyl butyrate ethyl 0-hexyl –Y « 2-ethylhexyl ethylhexanoate 2-ethylhexanoate « ?-yl 0-hexanoic acid—Y ¢ 2-ethylhexanoic acid 2- ethylhexane ethylhexane-1-1- “?- diol 3-01-cyclic diol 1mn-© cyclic “ cyclic lactone 0.2146008 ; ethers © , saturated and unsaturated ; Cpp ethers; butyl (gale n-butyl ether; "- ethylhexyl and butyl 2-ethylhexyl ether sale; trimolecular formula yo). The concentration of such organic compounds in aqueous media is conventionally described by the value .COD The value COD (where COD stands for Chemical Oxygen Demand) represents the amount of dichromate; expressed in oxygen equivalents that is consumed by the oxidizable components per liter of water. The value is determined by COD in a standard way, which is described, for example, in [Ullamnn's Enzyklopadie der technischen Chemie [Ullmann's Encyclopedia of 0 Industrial Chemistry] pp. 7716© 8; Volume 6-4th Edition (VAAN) It is noteworthy That before the excess water enters the transformational treatment plant; inside the river streams or other water-receiving spaces, it is necessary to significantly reduce its content of organic impurities YO to comply with the exact legal requirements regarding the maximum concentrations of pollutants in the contents of the excess water.

European Patent No. 719848 states: - A - A method by which the concentration of organic impurities present in the contents of excess water resulting from aldolization and subsequent hydrogenation reactions can be reduced. in the process; The above-mentioned three parts are combined with excess water and subjected to a pH of zero to +. © There is an organic phase which separates after this process and is removed and, if appropriate, then the excess water is extracted with monohydric alcohols which contain 8 or more carbon atoms in the molecule and/or with hydrocarbons which contain more than 6+ carbon atoms per molecule. It should be noted that the process is easy to perform industrially and makes it possible to remove at least 0,746 of the organic compounds present in the associated excess water. The extraction medium present after extraction and loading is subjected to organic compounds. by-products; and under special cases; to the distillation process for extraction. We find that the resulting distillation residue as well as an offset at the top of the distillation column contain a large part of the organic by-products and are supplied to thermal use. The extracted medium is recirculated by 1 by lateral divergence into the pada process); Completed with a newly prepared extraction medium. An important aspect of the method of European Patent No. 7194848 = a- consists in exposing 0 excess water of alkaline in general to a degree of pH of zero to 2 preferably from 1 to ¥ and this in turn supplies protonates Carboxylic acids (for example, JU) exist in the form of alkali metal salts (ALE) soluble in water, thus converting them into free carboxylic acids, and those free acids represent substances other than ALG that are soluble in water. Thus, there is evolution; to a greater or lesser extent; of an organic phase which is removed from the excess water; Which in turn may achieve a linear decrease in the .COD value and the presence of the mentioned pH also causes the solubility of the extraction medium in water to increase its extraction. The reason for this is that he determined that the solubility of the extraction media in water is dependent, Yo on the degree of pH, and is significantly lower in acidic media when present in basic media. Therefore, in acidic solutions; It contributes to a small degree to increase the Aad of the .COD

Although the decrease in pH followed by removal of the resulting organic phase; The excess water present in the process of European Patent No. =F = TV AAA plus water-soluble dissolved organic compounds; It still contains an amount of water insoluble organic compounds from which an emulsion is formed in the excess oo water. Thus, it is not possible to remove these materials from the excess water until the extraction step that follows the adjustment of the pH degree, and where compounds with a molecular weight Jal and high-boiling condensate products are also removed by Adee extraction; High temperatures are required in the distillation process of the extraction medium charged with these impurities; Which in turn leads undesirably to the increased formation of high-boiling condensate in the lower phase of the distillation process. Thus, there is no need to continuously increase the distillation temperature; Under practical operating conditions, relatively large amounts of the lower phase of the distillation process are continuously discharged from the distillation reactor; which also removes conjugate Jt = X hexanol each time; However it loses from the [ale] operation the rotation. This means that =X ethylhexanol recycled downstream for distillation needs to be supplied by freshly prepared 7-ethylhexanol 0. General description of the invention: - The purpose of the invention lies in supplying an improved way to clean the amounts of waste water from the aldolization process, as well as downstream hydrogenation, which allows for a more effective extraction of the extraction medium. Y. We find that these purposes and others are also advantages of the invention. You will notice from the following detailed description. Detailed description: The method of the invention is used to clean quantities of excess water from the preparation of alcohols, Cys « alcohols. This preparation includes an aldolization reaction; Also, YO is a subsequent hydrogenation process and then a final alcohol distillation process; The amounts of excess water consist of AD parts.

A

¢ aldolization An aqueous phase containing the catalyst resulting from the unsaturated (V) aldolization reaction formed a,B-unsatuated aldehyde and beta-aldehyde Wl excess water from purification (7) and aldolization during aldolization Excess water from cleaning the distillation residues of alcohol. (Y) 0 It also includes the accompanying excess water molecules that have been extracted with monohydric alcohols containing from A to 11 carbon atoms 8- 16 per molecule and/or with hydrocarbons having from 1 to 11 carbon atoms 6-12 per molecule; on: (a) in the aca direction of the extraction process; first the union of at least two of the molecules 0 the three excess water and adjust them to a pH of 0 to + and optionally remove the organic phase formed during this and (b) during the method; at least one of the three portions of the excess water is brought independently and/or of Jal is the excess water resulting from the preparation of the alcohols used in the method of the invention, where this preparation includes an aldolization reaction followed by hydrogenation and final distillation of the alcohol; These are the three fractions of excess water (1); (F) 5 (TF) which may include the water-soluble and non-water-soluble ALE organic compounds which have been identified in detail by separation. The combination filters used are In the method of the invention in liquid/liquid phase separators used for membrane dehumidification, in which the physical effect of amalgamation is on elements of a cylindrical base layer of specially formed fibers.Amalgamation filters of this type are known in the prior industry (see; for example Example Chemie-Technik ¢ Volume (19849) -18 pages; 1- (YY). It consists, for example, of plastic fibers of polypropylene or polytetrafluoroethylene 0 polytetrafluoroethylene, glass fibres, or metallic fibres.A working avoidance pressure of about 0.1 bar is necessary for flow through the fiber substrate.

Lexie flow passes through the lower fiber layer of the fusion filter; The water-insoluble organic compounds that eventually disperse with the excess water aggregate; Or it is imprisoned by a spacer organic layer which is actually on the lower fiber layer and forms a wet film. And we find that this moistened film moves with the moving surplus water stream to the outlet of the lower fiber oo layer; After that, large droplets of the organic phase separate at intervals of time and are separated by gravity only. It should be noted that this organic phase, in turn, can be separated from the excess water, which results in the excess water entering the next extraction process da of low COD; Thus, it is necessary to remove a small amount of organic compounds from the excess water during the Ye extraction. We find that the extraction medium left for the extraction process is loaded with only a small amount of organic components; The temperatures required in the distillation reactor used to extract the extraction medium are similarly low. Significantly this reduces the formation of other high-boiling by-products during the treatment of the extraction media used by distillation. Thus only small amounts of VO used in the lower phase of the distillation will need to be removed; As a result, the loss of the extraction medium during the treatment is significantly lower than in the case of the method subject of European Patent No. 94/88 71+-a-; @Alla Don't use the merge filter. This is accompanied by the advantage that: After the extraction medium is treated by distillation; Noticeably small amounts of newly prepared extraction medium required to be added. Ye It is worth noting that the middle connection of a fusion filter extends ; through the method subject of the invention; With a design that is used to improve the cleaning of excess water, which achieves effective multi-faceted effects. Another advantage of the method of the invention is based on the fact that amalgamation filters are suitable for a continuous operating model and all the methods involved in cleaning up the excess water fractions can be continuously performed in succession to the reactions of aldolization© and hydrogenation. Several embodiments have proven useful for the method subject of the invention.

oe The embodiment 1a includes first merging the parts of excess water (1) and (©) with each other from zero to + pH according to step (1); adjusting their pH to “; and optionally freeing them from The organic phase that is formed is then combined with water 1 and better than; and their connection in a cumulative manner through a fusion filter and then (Y) the excess with the part of the excess water exposing them to extraction. © and (¥) with (1) Involving again a first union of excess water molecules IY and there is a pH solubility of step (a); adjusting them to pH ly each other to; and optionally liberating them from the organic phase that forms; 1 0 to 6; preferably from which has already been contacted through (Y) and then the residual excess water union with the excess water fraction amalgamation filter and charge the mixture to the extraction process. Ve and (©) with each other ) 1) In the embodiment? a, the fractions of excess water in the amount of 0 to 6 pH are first combined according to step (1); adjusted to a pH of 7; optionally released from the organic phase that forms; and then passed 1 is preferred from which may (Y) through a merger filter. Then the remaining excess water is combined with the excess water portion passed through an amalgamation filter and then the mixture is shipped to extraction. pH and adjusted to pH 0 and (©) are first combined (7) (1) to ©; optionally released from the organic phase that forms; 1 zero to +; preferably then they are connected Collectively through an amalgamation filter and subjected to extraction. For excess water, inorganic acids pH are used and to adjust the degree of Y. Hydrochloric acid Jie inorganic acids phosphoric acid aes or + nitric acid ¢ sulfuric acid sulfuric acid Preference is given to sulfuric acid pal and since the sedimentation of solid particles present in the lower fiber layer of the connection; in the opposite direction of the current BDU _ fusion may hinder the effectiveness of separation; and it is from YO of amalgamation filter; a filter stage suitable for removing solid particles

AR

In the case of the extraction medium in the method subject of the invention; Alcohols are used from the carbon atoms in the molecule. It may be other than 11 AA containing the number 5 . branched or branched; Saturated or unsaturated and not necessarily using pure alcohols or isomeric alcohols. Suitable extraction media are also aad isomeric alcohols from alcohols of varying molecular size. One of the alcohols whose effectiveness has been proven is ©

Jills trimethyl —0 (0 » 2-ethyl hexanol - “decanolate nonanols isooctanol” 3,5,5-trimethylhexanol octanols And mixtures of isodecanols octanols and isodecanols decanols .isomeric decanols and isomeric decanols 00005

CNY In addition to alcohol; Hydrocarbons having from + to 10 carbon atoms per molecule can also be used as an extraction medium. Hydrocarbons may also be unbranched or af may be branched hydrocarbons; saturated or unsaturated. In which hydrocarbons have their own effectiveness, we find mixtures of different hydrocarbons, which are produced in the form of low-boiling fractions during petroleum distillation; Especially light fuel oil. And away from mixtures of alcohols or mixtures of various hydrocarbons; Vo el all can also use mixtures of alcohols and hydrocarbons to extract organic compounds from the surplus. The mixing ratio may extend over a wide range which is restricted mainly by the mixing of the components. The alcohols and/or hydrocarbons used in the invention have proven their efficiency as excellent extraction media for the organic materials usually present in the excess water fractions. It is also necessary that they be dissolved only to a very weak extent via the water phase. 0 Organic compounds are extracted from the excess water fractions by the method subject of the invention through familiar solvent extraction apparatus. Among the devices that have proven their usefulness, we find the extraction devices that were configured as a single stage or in the form of multiple stages, such as the extraction batteries for many pairs of the sedimentation basin in the mixer, which are connected one after the other. like that ; Extraction shafts having stable internal parts may be used; such as Yo padding columns; or have moving internal parts; like flipping poles; Amidst the extraction of means less and connected together or; He prefers ; On the contrary.

1"

The extraction medium can be easily reproduced by distillation and thus can be used repeatedly. The distillation residue as well as the dispersed top materials from the distillation column include the organic compounds to be removed and charged for thermal use; While the extraction medium is re-extracted by lateral deflection of the column and then re-circulated for the process

oe extraction.

The modern method is suitable for treating the excess water parts of the aldolization reaction, as well as hydrogenation in the reverse direction (LAN), depending on the aldolization process used and the starting materials used. Then the treatment process can be performed with aldol 6 0 . For example ; With metal hydroxide ssl carbonates or alkali metal amines as complementing agents

Ve catalysts as well as with aldehydes or ketones.

It should be noted that the possibility of making various modifications to the method subject of the invention without separating from the spirit of the invention will be realized that this invention aims to be specific and will be clarified by the appended protection elements.

Claims (1)

VY Elements of Protection 1-1 A method for cleaning excess water parts resulting from the preparation of alcohols; The aforementioned preparation includes an aldolization reaction as well as a follow-on hydrogenation v reaction; the excess water parts include the following three parts: (1) the aqueous phase containing the catalyst and the product From the aldolization reaction © .aldolization 1 ) º Wash water resulting from the purification process WY and soft a,B-unsaturated aldehyde pda produced during the aldolization process and + (¥) The wash water resulting from cleaning the remaining part of the alcohol distillation process -alcohol 4 The method includes the following steps: 0 ( ) and in the opposite direction of the extraction process; first combining at least two of the three particles 11 of the excess water and adjusting them to A degree of pH of 0 to 1.0 (b) During the method; at least one of the three fractions of the excess water is brought on an independent 1” shift and/or connected collectively with an amalgamation filter 5. (c) Extraction of a mixture of the three parts of excess water with monohydric alcohols ve having from A to 11 carbon atoms 8 to 16 carbon atoms 8 in the molecule with 11 hydrocarbons in them 1 to VY carbon atoms to 12 carbon atoms 6 in 1 molecule. 1 7- The method according to claim 1; In it, the surplus water parts (1) and (7) are first combined with 0 to each other and adjusted to a pH of zero to 6 according to step (a) and then combined v with the surplus water part (1) To form a mixture, said mixture is contacted through an amalgamation filter and then subjected to extraction. to 1 to pH. Method of claim 7; In which the degree of the Fy ¢ organic phase is set; - the method according to the element of protection? ; In it, the organic phase 1 pH formed during the “YY EN” temperature setting is removed 1 and () with (1), in which the parts of the excess water 1 are first united by the method according to the protection element -©*1 in an amount from zero to 6 according to step (a), then their pH is combined with each other and the set to 0 which has actually passed through the amalgamation filter 'to form a mixture; then ' ( Y ) with excess water part 0 ; said mixture is subjected to extraction. 3. to 1 to the pH value The method according to the claim © ¢ and in which the degree of + -1 is set; the organic phase of the claim © is removed and the organic phase Gay is removed Method 7-1 PH formed during the adjustment of the degree of the and (© (with (1)); and in which the portions of excess water 1 are first united by the method according to the element of protection - + 1 for step (a) and then combined Gay + their amount from zero to pH each other and adjusted to a degree To form a mixture ¢ the said mixture is contacted through an amalgamation filter and then (Y) with the excess water fraction +; it is then subjected to extraction. A of the claimant lp method 4-1 organic phase, in which the organic phase A method is removed according to the claim-1-01 pH formed during the pH adjustment; In it, the degree of the 1 method is set according to Claim 11-1. nitric acid “sulfuric acid”; hydrochloric acid v .phosphoric acid or phosphoric acid ¢ nitricacid 0” FY to pH value; In it, the degree of the 11th method is set according to the protection element VY organic phase; In it, the organic phase is removed by the method 1 according to the element of protection 1-1 “PH” formed during the adjustment of the degree of “