JPS5845408B2 - Hydrogenation purification method for alkylbenzene for detergents - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for purifying alkylbenzene for detergents.

More specifically, the present invention relates to a method for hydrogenating and purifying alkylbenzene for detergents.

Aromatic hydrocarbons, especially alkyl aromatic hydrocarbons obtained by nuclear alkylation of benzene with chlorinated paraffins or olefins, especially alkylbenzenes, are industrially produced in large quantities as raw materials for detergents, and their value is extremely high. .

This alkylbenzene is sulfonated with a sulfonating agent such as fuming sulfuric acid or sulfuric anhydride (sulfur trioxide) in order to become an active ingredient in detergents, and then neutralized with an alkaline substance.

One of the important items that determines the quality of alkylbenzene for detergents is that the degree of yellow coloration of the neutralized product after sulfonation must be extremely low. Purification by method is essential.

This purification method generally employs a very complicated process in which alkylbenzene distilled and recovered from the reaction solution after the alkylation reaction is washed with concentrated sulfuric acid and then neutralized or washed with water.

However, this method has a serious drawback in that it is a complicated process, takes time and money, and generates a large amount of waste such as waste sulfuric acid and waste water. Currently, there is a growing demand for establishment of such a system.

As one such method, a method of hydrogenating crude alkylbenzene for detergents has been proposed.

For example, Japanese Patent Publication No. 40-28350 discloses that an alkyl aromatic hydrocarbon obtained by condensing an aromatic hydrocarbon and an alkylating agent in the presence of a Friedel Krach type catalyst or an acidic catalyst is used as a hydrogenation catalyst. In the presence of
A method has been proposed for producing alkyl aromatic hydrocarbons with excellent sulfonation properties by carrying out hydrogen purification treatment at a reaction temperature of 300° C. or less under normal pressure or increased pressure.

However, it is stated that it is possible to use known catalysts such as palladium, platinum, nickel, copper-chromium, cobalt, and molybdenum as the hydrogenation catalyst used in this case. and it is unclear as to which catalyst will give the best results.

U.S. Pat. No. 3,454,666 also discloses a temperature range of about 50 to 200' F (about 10 to 93 C) and a temperature range of about 5 to 50 Peig (0.35 to 3.5 k) in the presence of a hydrogenation catalyst.
A method for hydrotreating crude alkylbenzene at a hydrogen pressure of g/crAG) is shown.
It is stated that as the hydrogenation catalyst used in this case, it is particularly suitable to use a catalyst in which 0.1 to 1% by weight of palladium is supported on an alumina carrier.

Furthermore, Japanese Patent Publication No. 48-34730 discloses that in the presence of a hydrogenation catalyst, a temperature range of about 20 to 125 °C, about 25 to 101
It has also been proposed to carry out hydrogenation at a hydrogen pressure of 000 Psi (approximately 1.75 to 70 kg/crrtG), but the hydrogenation catalysts used in this case include palladium supported on carbon, nickel supported on diatom, or platinum supported on carbon, and a catalyst which gives particularly favorable results is palladium supported on carbon, and when it contains from 0.2 to 6% by weight of palladium, based on the total weight of the catalyst. It is said to give the desired results.

Although several hydrogenation treatment methods have been proposed, the reality is that these methods have not yet been adopted industrially, and the main reason for this is that This is because there is a quality problem in that alkylbenzenes subjected to hydrogenation treatment by various methods do not exhibit a satisfactorily low degree of coloring of the sulfonated products.

The inventors of the present application focused on the great advantages of hydrogenation purification of alkylbenzene, and as a result of intensive research to overcome the deficiencies of the methods described in the above-mentioned literature and make this method industrially applicable, we found that The present invention was achieved based on the discovery that hydrogenation performance greatly changes depending on the amount of palladium used.

That is, the present invention was achieved as a result of investigating the reason why none of the above-mentioned known methods gives fully satisfactory results.

Alkylbenzene for detergents mainly has 10 to 14 carbon atoms.
The main component is alkylbenzene having one linear or branched alkyl group, and other impurities include polycyclic aromatic compounds such as alkylindene, alkylindane, alkylnaphthalene, alkyltetralin, anthracene, and alkylanthracene. Contains a small amount of olefins and conjugated dienes with non-aromatic unsaturated bonds.

The factors that influence the quality of alkylbenzene for detergents are the types and contents of these impurities, and it is known that the presence of alkylanthracene and olefins in particular has a serious adverse effect on anthracene.

Therefore, in purification by sulfuric acid washing and activated clay treatment,
The purification principle is to remove the above impurities by taking advantage of the large difference in sulfonation reactivity and adsorption between these impurities and alkylbenzene.On the other hand, in purification by hydrogenation, impurities, especially anthracenes and olefins, are removed. The purification principle of this method is to utilize the difference in hydrogenation reactivity between alkylbenzenes and alkylbenzenes to convert these impurities into compounds that do not have a negative impact on quality, while not allowing the nuclear hydrogenation reaction of the alkylbenzenes themselves to occur. be.

In the latter case, when the nuclear hydrogenation reaction of the alkylbenzene itself occurs, a neutral oil that is not sulfonated and a cycloolefin that significantly increases the yellow coloring of the sulfonated product are produced, resulting in the serious problem of contaminating the alkylbenzene.

The basic technical idea of conventionally known hydrogenation refining methods is to improve the selectivity of the hydrogenation reaction between coloring substances and alkylbenzene by controlling the hydrogenation reaction temperature and pressure within a relatively mild range. On the other hand, in order to achieve a suitable reaction rate, it was necessary to use a catalyst having a high loading of palladium metal.

However, even if the reaction conditions were mild, good selectivity could not always be achieved, and the quality of the resulting product did not give a fully satisfactory value. The known method also had a fatal flaw in that the price of the catalyst was significantly high.

Under these circumstances, the present inventors attempted a method that fundamentally overturned the technical concept of the known method, and unexpectedly obtained very favorable results, leading to the completion of the present invention.

That is, the present invention has acquired a technology that can limit the amount of palladium supported to an extremely low value, and uses the thus obtained palladium catalyst to purify crude alkylbenzene for detergents by hydrogenation treatment.

However, the present invention was completed based on the surprising fact that by employing such a method, a high quality alkylbenzene for detergents can be obtained which gives an extremely light-colored sulfonated product which could not be obtained by known methods. It is.

To illustrate the gist of the present invention, the presence of a palladium catalyst supported on the surface of a solid carrier at a ratio of 0.001 to 0.04% by weight, preferably 0.005 to 0.03% by weight of palladium metal. Under a temperature range of 95 to 160 °C, preferably 100 to 140 °C, and a hydrogen pressure range of 5 to 20 kg/cd (gauge pressure), preferably 7 to 1.5 kg/cfi (gauge pressure), By hydrogenating crude alkylbenzene, extremely high quality alkylbenzene for detergents can be obtained.

By using such a low supported palladium catalyst, a high-quality product can be obtained and the price of the catalyst can be significantly reduced, resulting in a very economical advantage.

The hydrogenation catalyst used in carrying out the present invention has a concentration of 0.00% by weight of palladium metal on the surface of a solid support.
1-0.04% by weight, preferably 0.005-0.03
It is a palladium catalyst supported in a proportion of % by weight.

As the solid carrier used in this case, a molecular sieve made of activated alumina or synthetic zeolite having a specific surface area of 100 m''/g or more as measured by the BET method is preferable, and gives a result of L.

Further, the shape of the carrier may be spherical, pellet-shaped, honeycomb-shaped, or powdered.

The method for supporting palladium on the carrier is not particularly limited, but may be carried out by immersing the carrier in an aqueous solution of a palladium compound, such as palladium chloride or palladium nitrate, or by spraying the aqueous solution uniformly onto the fence. Catalysts that have been dried or reduced with a suitable reducing agent such as formalin, hydrazine, hydrogen, etc. without drying can be suitably used.

In this case, when reducing with hydrogen, it is not always necessary to carry out the reduction treatment in advance, and it is also possible to carry out the reduction at the same time as the hydrogenation treatment of the alkylbenzene.

The amount of palladium supported on the catalyst is within the above range, but if it is out of this range, the effects of the present invention will not be exhibited.

The crude alkylbenzene for detergents to be hydrogenated may be produced by any method, but it is usually produced by a method such as that disclosed in Japanese Patent Publication No. 417569, that is, by using an alkyl halide or an alkyl halide as an alkylating agent. using an olefin and using benzene or other aromatic hydrocarbons as alkylating agent, such as toluene, xylene, naphthalene or mixtures thereof,
It is produced by an alkylation reaction carried out using an aluminum halide, such as anhydrous aluminum chloride, as the alkylation catalyst.

Alkylbenzene produced by this alkylation reaction is separated from other unreacted raw materials, by-products, etc. by distillation, but alkylbenzene purified by mere distillation yields a significantly dark-colored sulfonated product. It needs to be purified.

A wide range of reaction conditions can be adopted for the hydrogenation treatment, but the treatment temperature is 95 to 160' C1, preferably 10
In the range of 0 to 140°C, hydrogen pressure of 5 to 20 kg/
c (gauge pressure), preferably 7-15 kg/cm
By selecting from the range of (gauge pressure), extremely high quality products can be obtained.

The ratio between the amount of catalyst and the amount of liquid to be treated, that is, the amount of catalyst to be used, can be selected arbitrarily, but when hydrogenation treatment is carried out in a batch reaction format, the ratio of catalyst amount / amount of liquid to be treated (
Good results can be obtained by selecting the volume ratio) in the range of approximately 10 to 2 degrees.

The processing time at that time may be about 20 minutes to 5 hours.

In addition, when hydrogenation treatment is carried out in a continuous reaction format, a packed column reactor or the like is used to reduce the liquid hourly space velocity (SV) to 0.5.
A suitable result can be obtained by adjusting the time to about 4 hours.

A small amount of catalyst residue may be suspended in the alkylbenzene solution hydrogenated by such a method, but in that case, it can be removed by physical means such as filtration or centrifugation. .

The obtained alkylbenzene is sulfonated with a suitable sulfonating agent, such as oleum or sulfuric anhydride, and then treated with N.
A good detergent can be obtained by neutralizing it with a basic compound such as aOH, KOH, ammonia, or an organic amine.

However, the product obtained by the method of the present invention is an extremely light-colored sulfonated product, and its industrial significance is extremely large.

The reason why the low loading palladium catalyst of the present invention gives better results than the high loading catalyst is as follows.
The lower the palladium concentration, the greater the difference in adsorption to the catalyst surface between alkylbenzenes and anthracenes, which are color-causing substances, so that the nuclear hydrogenation reaction of alkylbenzenes is suppressed as much as possible, while the anthracenes, which are color-causing substances, are suppressed as much as possible. It is believed that the nuclear hydrogenation reaction proceeds rapidly and therefore the selectivity is significantly improved.

However, in the known method, the selectivity of the catalyst was not exhibited because a palladium catalyst with a high lees retention was used, and therefore a method was adopted in which the selectivity was increased by making the reaction conditions such as the reaction temperature mild. This limited the selectivity and made it impossible to obtain fully satisfactory results.

The idea on which the method of the present invention is based in the hydrogenation purification of detergent raw material alkylbenzene, which is the idea of increasing the selectivity of the catalyst itself by using a palladium catalyst with a low lees retention content, was completely unknown until now. It is truly surprising that it is extremely effective.

As explained in detail above, by employing the method of the present invention, a great effect can be obtained in that extremely high quality alkylbenzene for detergents can be produced economically and without producing waste.

The present invention will be explained below with reference to Examples, but the present invention is not limited in any way by the following Examples.

*Example 1 A chlorinated paraffin obtained by partially chlorinating a normal paraffin having a carbon number ranging from 10 to 13 was subjected to an alkylation reaction with benzene using an aluminum chloride complex catalyst.

After removing unreacted benzene and unreacted normal paraffin by distillation, hydrogenation treatment was performed under various conditions using crude alkylbenzene for detergents recovered by distillation as a raw material.

An example of manufacturing a palladium catalyst used in hydrogenation purification is shown below.

Add palladium chloride to distilled water of 1.334. 4 kg of granular activated alumina (KHA-24, manufactured by Sumitomo Chemical, specific surface area 160 m'/?) was immersed in a palladium solution dissolved in l' to support it, and then dried separately at 110°C to obtain 0.02% by weight. A palladium-alumina catalyst was produced.

The hydrogenation treatment was carried out by a batch reaction method in which the crude alkylbenzene and catalyst were charged into an autoclave with an internal volume of 2501711, and stirred for a certain period of time at a predetermined reaction temperature and hydrogen pressure.

After the hydrogenated solution was sent to each house, it was sulfonated with gaseous anhydrous sulfuric acid diluted with dry nitrogen gas and neutralized with NaOH to form sodium sulfonate. 10m
m cell) was measured, and the value was multiplied by 1ooo to determine the degree of coloration.

Table 1 shows the results when various catalysts were used in which the supported amount of palladium was 0.02% by weight.

The hydrogenation treatment conditions are a treatment temperature of 100°C and a hydrogen pressure of 8°C.
The treatment time was 4 hours, the amount of raw material used was 150 ml, and the amount of catalyst used was 7 i.

From the results in Table 1, it can be seen that alkylbenzenes for detergents having excellent quality can be obtained by the method of the present invention.

*For comparison, Table 2 shows the results when a catalyst supporting a metal other than palladium was used under the same conditions as above.

It is clear from the results in Table 2 that the catalyst used in the present invention is excellent.

Example 2 Hydrogenation treatment was carried out using the same raw materials as in Example 1.

The conditions for hydrogenation treatment are a treatment temperature of 100℃ and a hydrogen pressure of 8K.
g/c 77f (gauge pressure), treatment time 4 hours, amount of raw material used was 150 ml, and the amount of catalyst used was adjusted according to the amount of palladium supported.

Note that the specific surface area of the carrier is 16 om2/? granular activated alumina was used.

The results are shown in Table 3. It is clear from the results in Table 3 that the method of the present invention is superior.

Example 3 Hydrogenation treatment was carried out using the same raw materials as in Example 1.

Using 0.03% by weight palladium-alumina or 0.005% by weight palladium-alumina as a hydrogenation catalyst, the treatment temperature and hydrogen pressure were varied, the treatment time was 4 hours, and the catalyst was used for 150ml of raw material liquid. amount 71
And so.

Note that granular activated alumina with a specific surface area of 160 m''/? was used as the carrier.

The results are shown in Table 4. From the results in Table 4, it is clear that by employing the treatment conditions of the present invention, alkylbenzenes for detergents having extremely excellent quality can be produced.

Example 4 A continuous-flow reaction system was used in which a catalyst was packed in a steel pipe reaction tower with a height of 5 m and an inner diameter of 0.05 m, and the crude alkylbenzene and hydrogen were fed at a constant rate from the top of the tower. Hydrogenation treatment of crude alkylbenzene was carried out.

Table 5 shows the treatment conditions and the degree of coloration of the alkylbenzene sulfonated product obtained.

Note that the catalyst carriers used in the treatment all have a specific surface area of 1
60rn'/? It is a granular activated alumina (KHA-24 manufactured by Sumitomo Chemical) having the following properties.

The results in Table 5 also show that by employing the method of the present invention, extremely high quality alkylbenzene for detergents can be obtained.

Furthermore, no change in product quality was observed even after long-term operation, confirming that the low-load palladium catalyst had a sufficiently long life.

Furthermore, there were no problems with the detergent properties of the sulfonated product of the present invention, the necessary performance as a detergent such as biodegradability.

Claims (1)

[Scope of Claims] 1. In a method for purifying crude alkylbenzene for detergents by hydrogenation treatment in the presence of a hydrogenation catalyst, the hydrogenation treatment is performed using activated alumina loaded with 01001 to 0.04% by weight of palladium metal. Or in the presence of a synthetic zeolite catalyst, treatment temperature 95-160°C, treatment pressure 5-20
A method for purifying crude alkylbenzene for detergents, the method being carried out under conditions of kg/crA (gauge pressure). 2. The method according to claim 1, which uses a hydrogenation catalyst using activated alumina as a carrier, which has a specific surface area determined by the BET method of at least Loom/f. 3. The method according to claim 1 or 2, wherein the hydrogenation treatment is carried out at a reaction temperature of 100 to 140°C and a reaction pressure of cuff to 15 kp/rst (gauge pressure).