GB1570932A

GB1570932A - Process for removing unwanted sulphonic or sulphric acids from reaction products

Info

Publication number: GB1570932A
Application number: GB783077A
Authority: GB
Original assignee: Nippon Oil Corp
Current assignee: Eneos Corp
Priority date: 1976-02-27
Filing date: 1977-02-24
Publication date: 1980-07-09
Also published as: CA1086777A; FR2342262A1; NL7702053A; FR2342262B1; DE2707765A1; JPS6031522B2; JPS52103390A

Abstract

PURPOSE:To remove undesired acidic substances in a reaction mixture obtained by catalytic reaction using a strong acid type cation exchange resin as catalyst by contacting the mixture with hydrosulfite.

Description

(54) PROCESS FOR REMOVING UNWANTED SULFONIC OR SULFURIC ACIDS FROM REACTION PRODUCTS (71) We, NIPPON OIL COMPANY LTD., a Japanese Body Corporate, of 3-12, I-chome, Nishishinbashi, Minatoku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to particularly described in and by the following statement:- This invention relates to a process for removing unwanted acid substances from a reaction mixture obtained by a reaction catalyzed by a sulfonic acid-type cation exchange resin.

Many reactions catalyzed by sulfonic acid-type cation exchange resins have been known, and utilized in the industrial production of chemical compounds. In these catalytic reactions, acid substances such as free aromatic sulfonic acid or sulfuric acid contained in the sulfonic acid-type cation exchange resins tend to be entrained in the reaction product as a result of extraction or liberation thereinto, and this consequently causes various troubles.

Processes for producing compounds commercially by such catalytic reactions frequently resort to the practice of performing the reaction under conditions such that the unreacted starting mixture will be present in a considerably high concentration in the reaction system in order to increase the rate of reaction or inhibit side-reactions. The resulting reaction mixture is separated into the desired final product and the unreacted starting mixture by distillation, extraction or adsorption, the latter being recycled to the reaction system.

If the reaction mixture containing the sulfonic acid-type cation exchange resin is to be separated by distillation in such a separating step, a backward reaction or other side-reactions will take place by the effect of heat. If, on the other hand, the separation is effected by extraction or adsorption, the acid substances will impair the extracting agents or adsorbents.

Generally, strongly acidic substances are removed by neutralization with strongly basic substances such as sodium hydroxide, calcium oxide, or calcium hydroxide. It is difficult, however, to separate salts formed as a result of neutralization reaction, and moreover, the quantity of a basic substance to be added is considerably difficult to determine since the concentration of the effluent acid varies greatly according, for example, to the type of the catalyst, the temperature of the reaction, the type of the raw material, the flow rate of the effluent acid, and the reaction time.

It is also possible to use ordinary adsorbents capable of adsorbing acids, such as activated carbon, activated terra alba or silica-alumina. But these adsorbents have only a low adsorbing capacity, and a decrease in the concentration of an acid to be adsorbed results in a marked reduction in the acid-adsorbing ability of the adsorbents.

Accordingly, it is an object of this invention to provide a process which can overcome the disadvantages of the prior art methods, and which can easily remove unwanted acid substances substantially completely from a reaction product mixture containing them.

As a result of extensive investigations in order to achieve the object of the invention, the present inventors have found that hydrotalcite has an excellent ability to remove acid substances from reaction mixtures which result from reactions catalyzed with sulfonic acid-type cation exchange resins.

The present invention provides a process for separating unwanted free sulfonic acid or sulfuric acid from a reaction mixture obtained by a reaction catalyzed with a sulfonic acid-type cation exchange resin and containing the reaction product, one or more unreacted starting materials if remaining, the unwanted free sulfonic acid or sulfuric acid from the ion-exchange resin, and a reaction solvent if used, which comprises contacting the reaction mixture with hydrotalcite to transfer the unwanted free sulfonic acid or sulfuric acid into the hydrotalcite, separating the reaction mixture from which the free sulfonic acid or sulfuric acid has been removed, and recovering it.

Prior to contacting the reaction mixture with hydrotalcite, the unreacted starting materials and/or the reaction solvent may be at least partially removed by stripping.

The process of this invention is completely free from the defects of the prior art methods described above. Sulfonic acid or sulfuric acid extracted or liberated from a sulfuric acid-type cation exchange resin is almost completely transferred into hydrotalcite, and removed from the reaction mixture. Thus, a reaction mixture not containing the unwanted sulfonic acid or sulfuric acid can be recovered. As a result, all the inconveniences in the step of recovering the reaction product and subsequent steps can be eliminated.

The mechanism by which acid substances from the sulfonic acid-type cation exchange resin migrate from the reaction mixture to hydrotalcite has not been clearly known. It is presumed however that these acid substances are either adsorbed to hydrotalcite or react with it, or both of these phenomena take place.

The sulfonic acid-type cation exchange resin, as referred to in the present invention, includes, for example, styrene-derived sulfonic acid-type resins, and phenolsulfonic acid-type resins. The styrene-derived sulfonic acid-type ionexchange resins are obtained by sulfonating resins resulting from the copolymerazation of styrene with a compound containing at least two ethylenically unsaturated groups in the molecule, such as divinyl benzene, and usually have units represented by the following formulae.

and

The phenolsulfonic acid-type resins are usually obtained by condensing phenolsulfonic acid with formaldehyde, and have the following chemical structure.

(wherein n represents the degree of polymerization) Hydrotalcite used in this invention may be in its natural or synthetic form. In its naturally ocurring form it is also called manasseite and is an ore of a hydrated basic carbonate of magnesium and aluminum with impurities which occurs naturally in small quantities in the Ural district of U.S.S.R., for example. Hydrotalcite normally has the following chemical structure.

Mg6AI2(0H),6C03-4H20 or A12O3.6MgO.CO2. 1 2H2O Hydrotalcite can be synthetically prepared. One example of the method of synthesis is disclosed in "Nippon Kagaku Kaishi", Vol. 92, p. 514, 1971, and comprises continuously feeding an aqueous solution of aluminum sulfate, an aqueous solution of magnesium chloride or magnesium sulfate, and an aqueous solution of sodium carbonate into a reactor, stirring the mixture, and further feeding sodium hydroxide into the reactor so as to maintain the pH of the solution at 10I I . By varying the rates of feeding the aqueous solution of aluminum sulfate and the aqueous solution of the magnesium salt, double oxides of varying Mg/AI ratios can be obtained in the suspended state. The double oxides are collected by filtration, washed with water, and calcined at 500 to 7000C to afford synthetic hydrotalcites.

Usually, pure hydrotalcite has a magnesium/aluminum molar ratio of about 3, and is characterized by showing the following peaks in its X-ray diffraction pattern (JCPD 14191).

dA I/I, 7.69 100 3.88 70 2.58 20 2.30 20 1.96 20 1.85 10 1.75 10 1.65 10 1.53 20 1.50 20 1.28 10 Rad.FeKa, A 1.93728, Filter Mn.

The X-ray diffraction chart of hydrotalcite is shown in the accompanying drawing.

Synthetic hydrotalcites usually contain some impurities and this results in the mole ratio of magnesium/aluminum departing from 3 and being in the range 1 to 10.

Notwithstanding this, some of them show the X-ray diffraction pattern which is characteristic of pure hydrotalcite having a magnesium/aluminum mole ratio of about 3.

Such synthetic hydrotalcites are within the definition of hydrotalcite in this invention even if their magnesium/aluminum mole ratio deviates from about 3, and can be used to remove acid substances in accordance with the present invention.

There is no particular restriction on the types of reactions catalyzed with sulfonic acid-type cation exchange resins to give reaction mixtures from which unwanted acid substances can be removed by the process of this invention.

Examples of such catalytic reactions are listed below.

(1) Production of ethers from olefinically unsaturated hydrocarbons and alcohols.

(2) Production of alcohols by hydration of olefinically unsaturated hydrocarbons.

(3) Production of polyhydric alcohol ethers, especially glycol monoethers, from olefinically unsaturated hydrocarbons and polyhydric alcohols.

(4) Production of cyclic ethers by dehydrocyclization of diglycols.

(5) Production of alkyl aromatics by alkylation of aromatic compounds.

(6) Oligomerization of olefinic hydrocarbons.

(7) Isomerization of olefinic hydrocarbons for shifting their unsaturated bonds.

(8) Isomerization of hydrocarbons to provide products having a skeleton with a higher degree of branching.

(9) Aldol condensation of ketones and/or aldehydes.

All of the reactions exemplified above are essentially based on the catalytic action of the sulfonic acid group (RSO3eHo+) of the catalyst, and as a result of contacting of the reactants with the catalyst, free aromatic sulfonic acid or sulfuric acid is liberated or extracted into the reaction mixture obtained. The amount of unwanted acid substances contained in the reaction mixture differs according to the reaction conditions, but generally it is from about 100 to about 1000 ppm by weight.

Raw materials used in the above exemplified reactions are as follows: In reaction (1), olefinically unsaturated hydrocarbons containing 2 to 22 carbon atoms, preferably 3 to 10 carbon atoms, such as propylene, n-butene, i-butene, pentene, hexene or octene, and alcohols containing 1 to 32 carbon atoms, preferably 1 to 20 carbon atoms, such as methanol, ethanol, n-propanol, i-propanol, n-butanol, sec-butanol, hexanol, octanol, and. oleyl alcohol, are used. In reaction (2), the same olefinically unsaturated hydrocarbons as in reaction (1) are used. In reaction (3), the same olefinically unsaturated hydrocarbons as in reaction (1), and polyhydric alcohols, for example aliphatic glycols, containing 2 to 32 carbon atoms, preferably 2 to 20 carbon atoms, such as ethylene glycol, 1,2 propylene glycol, glycerol, diethylene glycol or triethylene glycol, are used. In reaction (4), diglycols having 2 to 32 carbon atoms, preferably 2 to 20 carbon atoms, such as diethylene glycol, dipropylene glycol or dibutylene glycol, are used. In reaction (5), monocyclic or polycyclic aromatic compounds containing 6 to 30 carbon atoms, such as benzene, toluene, xylene, cumene, tetralin, naphthalene, anthracene, trimethylbenzene, or tetramethyl benzene, are used. Examples of the alkylating agents used in reaction (5) are olefinically unsaturated hydrocarbons containing 2 to 22 carbon atoms, preferably 3 to 15 carbon atoms, such as propylene, n-butene, i butene, pentene, hexene, decene, or dodecene, and saturated halides containing 1 to 22 carbon atoms, preferably 1 to 15 carbons atoms, such as methyl chloride, methyl bromide, ethyl bromide, propyl chloride, butyl chloride, and dodecyl chloride. In reaction (6), the same olefinically unsaturated hydrocarbons are used. In reaction (7), olefinic hydrocarbons containing 4 to 22 carbon atoms, preferably 4 to 10 carbon atoms, such as butene-l, pentene-l or heptene-l, are used. In reaction (8), aliphatic or alicyclic saturated hydrocarbons containing 4 to 22 carbon atoms, such as butane, pentane, heptane or decane, and various petroleum fractions containing them, especially petroleum fractions used for gasoline, are employed.

The raw materials used in reaction (9) are ketones or aldehydes containing 1 to 20 carbon atoms, preferably 2 to 8 carbon atoms, such as acetaldehyde, acetone, propionaldehyde, and butyraldehyde.

The reaction conditions differ according to the type of reaction. In view of the catalytic nature of sulfonic acid-type cation exchange resins, the reaction is carried out usually at 0 to 2500 C, preferably 50 to 150"C. Temperatures outside this range are not preferred since at below 0 C, none of the aforesaid reactions proceed effectively, and at more than 2500 C, the raw materials and the sulfonic acid-type cation exchange resins are liable to be decomposed. The reaction pressure may be reduced pressures, but usually, normal atmospheric pressure to 50 atmospheres, preferably atmospheric pressure to 10 atmospheres, are employed.

The materials to be contacted with the catalyst may be in the form of gas or liquids.

Preferably, the catalyst is packed in a column, and the materials in fluid form are passed through it. There can also be employed a method in which the catalyst is suspended in the fluid materials, or a method in which the fluid materials are contacted with the catalyst fluidized by the materials.

The reaction mixtures obtained by the reaction (1) of producing ethers from olefinically unsaturated hydrocarbons and alcohols, the reaction (2) of producing alcohols by hydration of olefinically unsaturated hydrocarbons, and the reaction (3) of producing polyhydric alcohol ethers from olefinically unsaturated hydrocarbons and polyhydric alcohols are especially suitable for removal of unwanted acidic substances by the process of the present invention.

Examples of the reaction (1) are a reaction of obtaining diisopropyl ether from propylene and isopropyl alcohol, a reaction of obtaining methylisobutyl ether from isobutylene and methyl alcohol, and a reaction of obtaining isopropyl tertiary butyl ether from isobutylene and isopropyl alcohol.

These reactions are performed by contacting the reactants with a sulfonic acidtype cation exchange resin catalyst usually at a temperature of 20 to 2000 C, preferably 50 to 1800 C, and a pressure of 0 to 50 atmospheres.

These reactions are described, for example, in British Patent No. 957,000 and West German OLS no. 2,403,196.

Examples of the reaction (2) are a reaction of obtaining isopropyl alcohol by reacting propylene with water, and a reaction of obtaining tertiary butyl alcohol by reacting isobutylene with water.

These reactions are performed by contacting the reactants with a sulfonic acid-type cation exchange resin catalyst usually at a temperature of 50 to 2000C and a pressure of 0 to 50 atmospheres.

These reactions are described, for example, in West German Patent No.

2,147,737.

Examples of the reaction (3) include a reaction of obtaining ethylene glycol monoisopropyl ether from propylene and ethylene glycol, a reaction of obtaining ethylene glycol monoisobutyl ether from isobutylene and ethylene glycol, and a reaction of obtaining diethylene glycol monoisopropyl ether from propylene and diethylene glycol.

These reactions are performed by contacting the reactants with a sulfonic acid-type cation exchange resin catalyst usually at a temperature of 0 to 1500C, preferably 30 to 1200C and a pressure of 0 to 20 atmospheres.

These reactions are described, for example, in West German OLS No.

2,450,667.

In the catalytic reactions exemplified above to which the process of the present invention can be applied, a mixture containing the unreacted materials and a reaction solvent (if used) as well as the desired reaction product is usually withdrawn from the reaction zone in the form containing undesired acidic substances which have been liberated or extracted from the catalyst. According to the present invention the above reaction mixture can be directly contacted with hydrotalcite. If desired, prior to contacting with hydrotalcite, any matter, which can be readily removed by a simple operation such as stripping or standing, may be removed.

Where the reaction mixture contains the catalyst as a solid, it is preferably removed before contact with hydrotalcite.

A preferred method of contact is to pass the reaction mixture to be treated through a layer packed with hydrotalcite as in the case of the catalytic reactions described hereinabove. Or hydrotalcite can be contacted suspended in, or fluidized by, the fluid reaction mixture.

Hydrotalcite can be used as a powder or as particles preferably having a particle diameter of up to about 10 mm. For example, it can be used in the form of spheres or cylinders (extrudate). There is no particular limitation on the temperature at which the reaction mixture is contacted with hydrotalcite. For example, contacting temperatures of about 0 to 3000 C, preferably 0 to 1500C, can be employed.

According to the present invention contacting of the reaction mixture with hydrotalcite results in the transfer of almost all acid substances from the reaction mixture to hydrotalcite. The amount of hydrotalcite can be adjusted depending upon the acid concentration of the acidic solution containing acid substances to be removed. In a batchwise method, hydrotalcite is added usually in an amount of 0.1 to 50% by weight, preferably 1 to 20% by weight, to the acidic solution. In a flowing method, the acidic solution is usually passed at a rate of 1 to 1000 g, preferably 10 to 100 g, per gram of hydrotalcite per hour.

The following examples illustrate the process of this invention more specifically.

Example 1 90 g of a propylene/propane mixture containing 50% by weight of propylene was liquefied under pressure, and mixed with 1 mole of isopropyl alcohol. To the resulting solution was added 10 g of a styrene-derived sulfonic acid-type cation exchange resin (Amberlist (Registered Trade Mark) 15, a product of Rohm & Haas), and the mixture was allowed to stand at 1000C for 1 hour in a stirred reactor. After the reaction, the cation exchange resin was removed by filtration. Thus, a solution consisting of isopropyl alcohol and diisopropyl ether was obtained. The acid concentration of this solution was 1.0+10-' eq/l. 10.0 g of powdery hydrotalcite (synthetic hydrotalcite having the composition Mg6Al2(OH)1 6.CO2.4H2O) was added to this solution, and the solution was stirred for 10 minutes. Hydrotalcite was then removed by filtration to afford a neutral solution having an acid concentration of 1.2x10-7 eq/l. Distillation of the resulting neutral solution afforded 48.5 g of diisopropyl ether having a purity of 99.7%. From the bottom of the distillation tower, the unreacted isopropyl alcohol was recovered.

Example 2 One mole of propylene and 1 mole of methanol were liquefied under pressure and mixed. To the resulting solution was added 15 g of a phenolsulfonic acid-type ion exchange resin (Amberlite (Registered Trade Mark) IR-I), and the mixture was allowed to stand at 850C for 2 hours in a stirred reactor. After the reaction, the cation exchange resin was removed by filtration. Thus, 70 g of a mixture of methanol and methyl isopropyl ether was obtained. The acid concentration of this solution was 2.1+10-2. To the resulting solution was added 0.8 g of hydrotalcite (synthetic hydrotalcite having the composition Mg6Al2(OH)16.CO3.4H2O) shaped into cylindrical fragments having an average diameter of about 0.8 mm and an average length of about 1 mm, and the solution was stirred for 30 minutes.

Hydrotalcite was then removed by filtration to afford a neutral solution having an acid concentration of 2.2+ 10-7 eq/l. Simple distillation of the resulting solution gave 55 g of methyl isopropyl ether having a purity of more than 99.5%.

Example 3 The unreacted isopropyl alcohol recovered in Example 1 was again reacted under the conditions set forth in Example 1.

No deterioration of the catalyst was observed, and the same results as in Example 1 were obtained.

Example 4 A cylindrical reactor having an inside diameter of 5 cm and a height of 20 cm was charged with 200 g of the same styrenederived sulfonic acid-type cation exchange resin as used in Example 1. A starting mixture consisting of 1 mole of isopropyl alcohol and 140 g of mixed butylene containing isobutylene with a purity of 40% in the liquefied state under pressure was passed at a flow rate of 2,000 gZhr at 500C through the reactor packed with the cation exchange resin. The effluent from the reactor was passed through a neutralizing pot filled with 20 g of the same hydrotalcite as used in Example 2. Then, the neutralized effluent was distilled.

In the above procedure, the conversion of isopropyl alcohol was 98%, and isopropyl tertiary butyl ether having a purity of more than 99.7% was obtained.

Furthermore, in the above procedure, the acid concentration of the effluent from the reaction before passage through the neutralizing pot was 3x10-3 eq/l, and that after passage was 1.1 x O-7 eq/l.

Example 5 A starting mixture consisting of 62 g of ethylene glycol and 1 mole of isobutylene was liquefied under pressure, and passed into a reactor charged in advance with 15 g of a styrene-derived cation exchange resin (obtained by sulfonating a copolymer of styrene and 5% divinyl benzene and being in the form of particles having a particle diameter of 20 to 50 mesh). With stirring, the mixture was allowed to stand at 500C for 5 hours. Then, the cation exchange resin was removed Five grams of the same hydrotalcite as used in Example 1 was added to the remaining solution having an acid concentration of 1.0:: 10.2 eq/l, and the solution was stirred for 30 minutes. Then, hydrotalcite was separated, and the remaining neutral solution having an acid concentration of 3.0x 10-7 eq/l was distilled.

The conversion of ethylene glycol was 98%, and ethylene glycol mono(tertiary butyl) ether having a purity of more than 99% was recovered.

Example 6 A starting mixture consisting of 1 mole of propylene glycol and 1 mole of propylene was liquefied under pressure, and passed at 90"C at a rate of 2,000 g/hr into a cylindrical reactor having an inside diameter of 5 cm and a height of 20 cm which had been packed with 220 g of a styrene-derived sulfonic acid-type cation exchange resin (obtained by sulfonating a copolymer of styrene and 10% of divinyl benzene and being in the form of particles having a particle diameter of 20 to 50 mesh). The effluent from the reactor was passed through a cylindrical neutralizing pot packed with 100 g of the same hydrotalcite as used in Example 2. Subsequent distillation afforded propylene glycol monoisopropyl ether having a purity of 99.5%. The recovery of this product was 98%.

In the above procedure, the acid concentration of the effluent from the reactor was 5:: 10.2 eq/l before flashing, 4x10-3 eq/l after flashing, and 1.1x10-7 eq/l after neutralization.

Comparative Example When the reaction mixture obtained by the reaction shown in Example 6 was distilled without treatment with hydrotalcite, the recovery of propylene glycol monoisopropyl ether formed as a result of the reaction was only 17%.

As a result of distillation, about 4.8 moles of propylene per mole of the propylene glycol monoisopropyl ether recovered was obtained from the top of the distillation tower. At the bottom of the tower, propylene glycol was deposited in an amount almost equimolar to propylene.

Example 7 A starting mixture consisting of 1 mole of propylene and 20 moles of water was passed at a flow rate of 300 g/hr at 100 to 1200C through a cylindrical reactor having an inside diameter of 5 cm and a height of 20 cm which had been packed with 220 g of the same cation exchange resin as used in Example 1. The reaction solution had an acid concentration of 2.5:: 10.2 eq/l. The reaction solution was passed at a flow rate of 2,000 g/hr through a cylindrical neutralizing pot packed with 100 g of the same hydrotalcite as used in Example 2. The acid concentration of the resulting solution was 1.6x10-7 eq/l.

Example 8 A 200 ml. stainless steel vessel equipped with a stirrer was charged with 80 g of diethylene glycol and 30 g of a styrenederived sulfonic acid-type cation exchange resin (Amberlist 15), and with stirring at 1300C the reaction was performed for 10 hours. After the reaction, the reaction solution was filtered to remove the cation exchange resin. The resulting solution had an acid concentration- of 5.7x}0-1 eq/l. To the resulting solution was added 10.0 g of the same hydrotalcite as used in Example 1, and the solution was stirred for 15 minutes.

Hydrotalcite was then removed by filtration to afford a neutral -solution having an acid concentration of 1.1x10-7 eq/l. Distillation of the resulting neutral solution afforded 52 g of p-dioxane having a purity of 99.5%.

Example 9 A 200 ml glass flask equipped with a reflux condenser and a stirrer was charged with 20 g of a styrene-derived sulfonic -acidtype cation exchange resin (Amberlist 15) and 60 g of p-xylene. Gaseous propylene was passed into the solution through a blowing tube at a flow rate of 400 ml/min., and reacted for 3 hours. After the reaction, the reaction mixture was filtered to remove the cation exchange resin. As a result, 2,5 diisopropy- 1 ,4-dimethylbenzene was obtained in a yield of 99% with a p-xylene conversion of 100%. The resulting solution had an acid concentration of 2.5x 10-' eq/l, and to this solution was added 5.0 g of the same hydrotalcite as used in Example 1. The solution was stirred for 15 minutes, and hydrotalcite was removed by filtration. A neutral solution having an acid concentration of 1.5x 10-7 eq/I was obtained.

Example 10 A l-liter stainless steel vessel equipped with a stirrer was charged with 125 g of a styrene-derived sulfonic acid-type cation exchange resin (Amberlist-15), 195 g of benzene and 86 g of a mixture of n-olefins having 10 to 14 carbon atoms, and with stirring at 1200C, the reaction was performed for 6 hours. After the reaction, the reaction mixture was filtered to remove the cation exchange resin. A chromatographic analysis of the resulting solution showed that 88.5% of the starting nolefin mixture had been converted to alkylbenzenes. This solution had an acid concentration of 3.0x10-' eq/l. To the solution was added 15.0 g of the same hydrotalcite as used in Example 1, and the solution was stirred for 30 minutes. Then, hydrotalcite was removed by filtration to afford a neutral solution having an acid concentration of 1.3+10-7 eq/l.

WHAT WE CLAIM IS: 1. A process for separating unwanted free sulfonic acid or sulfuric acid from a reaction mixture obtained by a reaction catalyzed with a sulfonic acid-type cation exchange, resin and containing the reaction product, one or more unreacted starting materials if remaining, the unwanted free sulfonic acid or sulfuric acid ascribable to the ionexchange resin, and a reaction solvent if used, which comprises contacting the reaction mixture with hydrotalcite to transfer the unwanted free sulfonic acid or sulfuric acid into the hydrotalcite, separating the reaction mixture from which the free sulfonic acid or sulfuric acid has been removed, and recovering it.

2. The process of claim 1 wherein prior to contacting the reaction mixture with hydrotalcite, the unreacted starting materials and/or the reaction solvent is at least partly removed by stripping.

3. The process of claim 1 wherein the amount of the free sulfonic acid or sulfuric acid contained in the reaction mixture is 100 to 1,000 ppm by weight.

4. The process of claim 1 wherein the reaction product is an aliphatic ether obtained by reacting an ethylenically unsaturated aliphatic hydrocarbon containing 2 to 22 carbon atoms with an aliphatic monohydric alcohol containing 1 to 32 carbon atoms.

5. The process of claim 1 wherein the reaction product is a glycol monoether obtained by reacting an ethylenically unsaturated aliphatic hydrocarbon containing 2 to 22 carbon atoms with a polyhydric alcohol, containing 2 to 32 carbon atoms.

6. The process of claim 1 wherein the reaction product is an aliphatic monohydric alcohol obtained by reacting an ethylenically unsaturated aliphatic hydrocarbon containing 2 to 22 carbon atoms with water.

7. The process of claim 1 substantially as herein before described in any of examples 1 to 10.

8. The reaction mixture defined as in claim 1 and separated from free sulfonic acid or sulfuric acid

Claims

claims 1 to 7.