FR2481700A1 - Purification of ether sulphonate solns. - by treatment with ethylene oxide or propylene oxide - Google Patents

Abstract

Aq. solns. of ether sulphonates (I) of formula R OCH2CHR1)z-O-CH2CHR1CH2SO3A (where R is 1-30 C (substd.) alkyl, 2-30 C (substd.); alkenyl, 7-28 C aralkyl or aryl subst. by one or more 1-18 C alkyl gps. z is 1-40, A is an alkali metal cation), contg. at least bisulphite impurities are purified by contact with ethylene oxide or propylene oxide at room temp - 250 degrees C for 1/4 - 24 hrs. The two phases formed are sepd.; the upper contg. purified (I) and the lower contg. the impurities. (I) are surfactants, esp. useful in petroleum recovery. Removal of ionic impurities improves their effectiveness and standardises the HLB.

Description

The present invention relates to the purification of organic sulfonates and more particularly organic ether sulfonates.

Organic sulfonates such as organic ether sulfonates are becoming more and more important due to their use in liquid detergents, particularly for the preparation of relatively salt-free detergents with good solubility characteristics. Even more recently, it has been found that compounds of this general type are useful materials when used as surfactants for processes of enhanced oil recovery.

 In many cases, the chosen process used for the production of ether sulfonates often leads to a product in which there are impurities which cannot be tolerated otherwise due to the end applications envisaged for these impure products. In many cases, the impurities are in the form of various organic and inorganic ionic substances. Thus, for example anions such as sulfite and sulfate anions may be present and somewhat interfere with the activity of ether sulfonate in the chosen application. In other cases, diionic impurities such as disulfonates and disulfinates, may be present. In still other cases, inorganic and organic impurities of this type or other impurities are present.

 As an example of the above, it has been determined that for a chemical to be useful as an additive to promote oil recovery, it must have a correct hydrophobic-hydrophilic balance or ratio. Exaggerated amounts of diionic impurities destroy this desired balance, which leads to less activity of the active ingredient.

Knowing a purification process j. organic ether sulfonates by ridding them of harmful ionic products of the organic or inorganic type, such as those mentioned above or such as other products, would constitute substantial progress in the art.

The main object of the present invention is therefore to provide a process for purifying organic ether sulfonates, these sulfonates thus being rid of harmful ionic impurities which tend to interfere with the final action of the ether sulfonate obtained. The invention has the specific purpose of to provide the purification process which has just been mentioned and which can be carried out simply and economically without resorting to sophisticated equipment and at multiple stages.

The objects mentioned above and the advantages of the present invention will become apparent on reading the detailed description below.

où R est un radical alcoyle en C1 - C30s un radical alcényle en C2-C30, un alcoyle substitue en C -C3D, un alcényle substitué en C2'C30, un radical alcaryle contenant un ou plusieurs groupes alcoyle en C1-C1B, substitué sur le groupe aryle précité et un radical aralcoyle contenant de 7 à 26 atomes de carbone, Ra est H ou CH3, z est compris entre 1 et 40 et A est un cation de métal alcalin ou de métal alcalinoterreux, procédé caractérisé en ce qu'on met en contact la solution aqueuse précitée avec de oxyde d'éthylène ou de l'oxyde de propylène et en ce qu'on sépare une couche aqueuse supérieure résultante d'éther sulfonate purifie d'une couche acqueuse inférieure contenant ltimpu- reté précitée.According to its most general embodiment, the present invention comprises a process for the purification of aqueous solutions of ether sulfonates which contain at least one impurity constituted by a bisulfite, these ether sulfonates having the formula

where R is a C1-C30 alkyl radical, a C2-C30 alkenyl radical, a C -C3D substituted alkyl, a C2'C30 substituted alkenyl, an alkaryl radical containing one or more C1-C1B alkyl groups, substituted on the aforementioned aryl group and an aralkyl radical containing from 7 to 26 carbon atoms, Ra is H or CH3, z is between 1 and 40 and A is an alkali metal or alkaline earth metal cation, process characterized in that brings the above aqueous solution into contact with ethylene oxide or propylene oxide and separating an upper aqueous layer resulting from purified ether sulfonate from a lower aqueous layer containing the above impurity.

In more detail, the ether sulfonates described in a general manner above which are subjected to the purification process described in the present description are known materials and it is not necessary to describe them in detail in the present description. . In addition, their method of preparation can be chosen from a certain number of techniques described. Neither the class of ether sulfonates described in this description nor their process for preparation are part of the present invention.

Likewise, the ionic impurities which may be present and which are separated from the ether sulfonates by means of the process of the present invention can be of various types. The quantity of impurities present and their particular ionic form depend to a large extent on the process chosen for the preparation of the ether sulfonates to be purified. In any case, it has been found according to the present invention that the purification process is applicable to the separation of monoionic and polyionic impurities, both inorganic and organic. Thus, for example, these impurities can be in the form of anions such as sulphate, sulphite, bisulphate, bisulphite and in the form of analogous ions. De marne, the impurities can be in the form of sulphonates and diionic organic sulfinates. The invention is in particular applicable to the elimination of such diionic organic compounds and sulfite or bisulfite ions.

où R a la signification indiquée ci-dessus, R1 est H ou
CH3 et z est compris entre 1 et 40, avec un halogénure d'alcoyle ayant la formule
XCH2CR1= CH2 où X est un halogène et R1 est H ou CH3, en présence d'une base de manière à produire un éther allylique ayant la formule : :

ou R, R1 et z ont les significations indiquées ci-dessus et à faire réagir cet éther allylique avec un bisulfite de métal alcalin tel que le bisulfite de sodium ou de potassium de manière à produire un éther sulfonate de formule

où A est un cation de métal alcalin ou de métal alcaline terreux.According to a particular procedure for preparing the ether sulfonates defined above, the diionic organic compounds and the bisulfite remain present in the form of impurities. This process described in prior British patent NO 156 66 55 in the name of the applicant consists in reacting an alkoxylated alcohol having the formula

where R has the meaning indicated above, R1 is H or
CH3 and z is between 1 and 40, with an alkyl halide having the formula
XCH2CR1 = CH2 where X is a halogen and R1 is H or CH3, in the presence of a base so as to produce an allyl ether having the formula::

or R, R1 and z have the meanings indicated above and to react this allyl ether with an alkali metal bisulfite such as sodium or potassium bisulfite so as to produce an ether sulfonate of formula

where A is an alkali metal or alkaline earth metal cation.

The ether sulfonate containing the impurities is purified by contact with ethylene oxide or propylene oxide in any manner allowing suitable intimate contact. This purification contact can for example be carried out in an autoclave. Furthermore, the purification itself can be carried out with a wide range of process variables such as time, temperature, pressure, etc. Usually, the purification is carried out at a temperature between about room temperature and about 250gC. More often, the purification temperature is between 25 and 200 ° C. and most frequently, it is between approximately 50 and approximately 150 ° C. Likewise, the contact time can be varied considerably between approximately 1/4 hour and approximately 24 hours. More often, the purification stage is completed one to one: 10 hours. In addition, although the purification can be carried out at atmospheric pressure, it is usually more advantageously carried out at pressures above atmospheric pressure or autogenous pressures. Usually, the pressure is between about 0.35 and 35 kg / cm2 (gauge pressure). Most often the pressure is between 0.35 and 7 kg / cm2.

In addition, the quantity of purification reagent constituted by ethylene oxide or propylene oxide or by a mixture of the two can be varied within wide limits. Usually, a slight excess of reagent is present, relative to the quantity of impurities present, this quantity being able to be determined by means of known analytical techniques If, for example, bisulfite is present, it can be determined by means of known procedures such as titration. In addition, if diionic organic substances are present, high pressure liquid chromatography can be used. After determining the quantity of impurities present, ethylene oxide or propylene oxide can be added in equal or excess molar quantities. For example, an excess of 6 to 10% of oxide is used . Usually, if a diionic organic product is present, it suffices to react it with only enough ethylene oxide or propylene oxide to transform the impurity into a monoionic material. Thus, it is only necessary to add half a mole of the reagent constituted by the oxide by the 'diionic impurity present. Furthermore, if an impurity such as sodium bisulfite is present, at least one mole of ethylene or propylene oxide or a mixture of the two per mole of sodium bisulfite present as an impurity.

 The process of the invention implies that the purification is carried out while the ether sulfonate is dissolved in an aqueous medium. This medium can be liteau itself, but it is preferably constituted by a mixture of calf and an organic solvent miscible with water such as an alcohol formed by a lower alkyl group, preferably containing from 1 to 4 carbon atoms. As typical reagents of this type, there may be mentioned isopropyl alcohol.

 When an ether sulfonate in water-alcohol solution is treated with ethylene oxide, propylene oxide or a mixture of these oxides, two distinct layers are observed. The lower layer is found to contain substantially all of the foregoing impurities in a modified chemical form, while the upper layer contains the purified ether sulfonate or the active ingredient. The two layers are then simply separated from each other so as to obtain an ether sulfonate solution having surprising purity.

 The following nonlimiting examples illustrate the purification process of the invention. It should be understood that numerous modifications can be made with regard to the embodiment described without departing from the scope of the invention.

obtenue par chauffage de ce mélange à 1OOOC et sous une pression d'air de 1,4 kg/cm2 pendant une heure, suivie par un maintien à 1200C et à une pression d'air de 3F5 kg/ cm2 pendant une heure, se trouvait sous forme d'une solution homogène.L'analyse a indiqué la présence d'acide fort (1,06 meq/g) et de 0,02 % de Cl
EXEMPLE 2
A 327 g du produit brut décrit dans 1' exemple 1 contenu dans un autoclave agité d'une capacité de 1 litre, on a ajouté 12 g d'oxyde d'éthylène en une période d'une heure à environ 1100C. Après une période de digestion d'une heure et demie à 110 C et après refroidissement à température ambiante, on a fait passer le contenu de l'autoclave dans un entonnoir de séparation avec isolement de deux couches. La couche inférieure (73,5 g) s'est révélée comme contenant 2,0 meq/g d'acide fort et 1,4 % de l'ingrédient actif, c'est à dire du sel sulfoniqua désiré comme cela résulte de données analytiques. La couche supérieure se présentait sous forme d'un liquide jaune pâle contenant uniquement 0,5 meq/g d'acide fort et presque 99 % du sel sulfonique désiré.EXAMPLE I
A mixture of allylated nonylphenol ethoxylate (4 mole adduct) (75 g), NaHSO3 (35.4 g), KN03 (2 g), H2O (150 ml) and tbutanol (150 mol) was introduced. ) in a dry, clean air-purged autoclave. The resulting material

obtained by heating this mixture to 1OOOC and under an air pressure of 1.4 kg / cm2 for one hour, followed by holding at 1200C and at an air pressure of 3F5 kg / cm2 for one hour, was in the form of a homogeneous solution. The analysis indicated the presence of strong acid (1.06 meq / g) and 0.02% of Cl
EXAMPLE 2
To 327 g of the crude product described in Example 1 contained in a stirred autoclave with a capacity of 1 liter, 12 g of ethylene oxide were added over a period of one hour at approximately 1100C. After a digestion period of 1.5 hours at 110 ° C. and after cooling to room temperature, the contents of the autoclave were passed through a separation funnel with isolation of two layers. The lower layer (73.5 g) was found to contain 2.0 meq / g of strong acid and 1.4% of the active ingredient, i.e. the desired sulfoniqua salt as shown by data analytical. The upper layer was in the form of a pale yellow liquid containing only 0.5 meq / g of strong acid and almost 99% of the desired sulfonic salt.

EXAMPLE 3
In the same manner as that described in Example 1, the allylic compound (75 g), NaHSO 3 (35.4 g) was heated,
KN03 (2 g), t-butanol (150 ml) and H2O (150 ml) at 100 C in the presence of air (2.1 kg / cm2) for one hour, then at 1200 for one hour (gauge pressure d air (3.5 kg / cm 2) Analysis of the resulting homogeneous mixture revealed 0.955 meq / g of strong acid and 0.32 meq / g of sulfonate.

EXAMPLE 4
As in Example 2, the product formed in Example 3 was treated (315 g of crude reaction mixture) with propylene oxide - (15 g) at 110 C for approximately Z hours. Analysis of the crude two-phase mixture indicated that most of the strong acid
(undesirable) was concentrated in the lower phase
(47 g in the layer, 1.90 meq / g). Remarkably, the upper phase contained an amount greater than 99% of the desired active ingredient constituted by ether sulfonate and representing an amount of 256 g of straw yellow liquid.

EXAMPLE 5
The sulfonation of the allyl ether of the adduct of 3 moles of ethylene oxide and dodecylphenol was carried out by the following method
A mixture of 160 g of allyl ether of the adduct of 3 moles of ethylene oxide and dodecylphenol (342 meq), 160 g of isopropyl alcohol, 350 g of water was heated to 550C. 6.3 g of sodium sulfite (50 meq) and 30 g of a 25% solution of sulfonate from a previous preparation (14 meq) acting as an emulsifier and neutralized to pH 7.2 by means of '' A 33> 5 aqueous solution of sodium metabisulfite.

Air was bubbled through the mixture at the rate of 6 ml / minute. The metabisulfite solution was added over 7 hours at a rate sufficient to keep the pH constant.

 Iodometric analysis of the product revealed a total bisulfite content of 0.068 meq / g.

 The reaction which has just been described was then repeated. When it was finished, 2 ml of ethylene oxide was added; the pH rose to 9.12. After removal of the alcohol solvent by distillation, the bisulfite content was only 0.027 meq / g.

EXAMPLE 6
The sulfonation of allyl ether was carried out only of the adduct of 4 moles of ethylene oxide and n-octanol using the process described in Example 5. At the end of the reaction, the sulfite concentration was 0.410 meq / g and pH 7.2. To 870 g of the product was added 6 g of propylene oxide and digested at 60 ° C. overnight. The pH rose to 12.9 and the sulfite content fell to 0.149 meq / g.

Claims (5)

 1. Process for the purification of aqueous solutions of ether sulfonates containing at least one impurity constituted by bisulfite, these ether sulfonates having the formula

where R is a C1 30 alkyl group> a C2 -C30 alkyl alken group a substituted C ~ C30 alkyl group  i 30 ′ a C2-C30 substituted alkenyl group, an alkaryl group containing one or more C1-C18 alkyl groups, substituted on the abovementioned aryl group and an aralkyl group containing from 7 to 26 carbon atoms, R1 is H or CH3, z is between 1 and 40 and A is an alkali metal or alkaline earth metal cation, essentially characterized in that the above-mentioned aqueous solution is brought into contact with ethylene oxide or propylene oxide and separating a resulting upper layer of purified ether sulfonate from a lower aqueous layer containing the above-mentioned impurity.  2. Method according to claim 1, characterized in that the aqueous solution is a mixture of water and an alcohol.  3. Method according to claim 2, characterized in that the alcohol has from 1 to 4 carbon atoms.  4. Method according to claim 3, characterized in that the alcohol is isopropyl alcohol. 5. A method according to any of claims 1 to 4, characterized in that R1 is H.