JP3063305B2 - Method for producing purified indene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing coal tar fractions.
The present invention relates to a method for producing purified indene.

[0002]

2. Description of the Related Art Tar acids coexist in a coal tar fraction containing indene, but it is difficult to completely remove the tar acids by distillation, which is an obstacle to the improvement of indene purity. . The tar acid in the coal tar fraction can be removed by washing with an alkaline aqueous solution.However, if the coal tar fraction is washed with an alkaline aqueous solution as it is, a large amount of an alkaline aqueous solution needs to be used, and alkaline wastewater is also removed. A large amount of by-products is not preferable as an industrial method. JP-A-62-327
Japanese Patent No. 31 discloses a method in which a tar gas oil having a boiling point of 135 to 195 ° C. is used as a raw material, which is subjected to a distillation treatment to obtain an indene fraction having an indene content of 76% by weight. A method is shown in which a distillation treatment is performed again after the treatment. In this method, since the washing treatment using an alkaline aqueous solution is performed on the indene component that has been concentrated to a high concentration in advance, there is an advantage that the proportion of the alkaline aqueous solution used may be small, but
Nevertheless, about 3 times the amount of the aqueous alkali solution is used for the indene fraction. Therefore, this method is still not satisfactory in using a large amount of alkali.

[0003]

SUMMARY OF THE INVENTION The present invention provides a method for obtaining high-grade indene from which tar acids have been completely removed by using a small amount of alkali when washing an indene fraction with an aqueous alkali solution. Is the subject.

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is,
According to the present invention, (i) obtained from coal tar distillation
Boiling point from phenol after alkaline washing of carbol oil
At least 0.1% by weight of a high boiling tar acid component
Indene-containing deoxidized carbol oil or (ii) coulter
Alkali washing of naphthalene oil obtained from toluene distillation,
High boiling point higher in boiling point than phenol obtained by distillation
Indene containing at least 0.1% by weight of
Using a naphthalene-containing gas oil as a feedstock, distilling the distillate to remove the high-boiling tar acid component substantially completely, and treating the indene-containing fraction obtained in the distillation step with an aqueous alkali solution An alkali washing step, wherein the alkali use ratio in the alkali washing step is NaO
0.005-0. 01 (g-NaOH / g-
Method for producing purified indene, characterized in that an oil) is provided.

The feedstock oil used in the present invention is a coal tar fraction containing indene, phenol, and high-boiling tar acids such as cresol, xylenol, and ethylphenol. 0.1 to 10% by weight, phenol: 0.1 to
It contains 10% by weight and indene: 20 to 90% by weight. Such distillate deacidification carbol oil and after alkali washing carbolic oil obtained from tar distillation, naphthalene oil obtained from tar distilled alkali washing, include naphthalene-gas oil obtained by distillation Can be
In addition, the high-boiling tar acid component referred to in the present specification means phenols having a higher boiling point than phenol.

In the present invention, the raw oil is subjected to a distillation treatment to remove a high-boiling tar acid component, and then subjected to an alkali washing treatment using an aqueous alkali solution. The distillation treatment is preferably carried out by a two-stage distillation method. For this purpose, in the first distillation column, a boiling point component lower than indene is removed as a top component, and in the second distillation column, a high boiling point component higher than indene is removed. The tar acid component is removed as a bottom component, and an indene fraction from which the high boiling tar acid component has been removed is obtained as a top component. In the present invention, the high-boiling tar acid component in the indene fraction during distillation of the feedstock oil is substantially zero% (0. 0%) from the viewpoint of reducing the proportion of the aqueous alkali solution used in the subsequent alkali washing step. 5% by weight or less). According to our research,
In alkaline washing of indene containing tar acid, high-boiling tar acid components such as cresol, xylenol and ethylphenol are much more difficult to remove by extraction than phenol, and a large amount of alkali is required for complete removal. It was found to be needed.

The aqueous alkaline solution used in the present invention includes:
An aqueous solution of a strong alkali such as sodium hydroxide, potassium hydroxide, ammonium hydroxide or the like is preferable, and its concentration is usually 0.1 to 20% by weight, preferably 0.5 to 10% by weight. The amount of the aqueous alkali solution varies depending on the alkali concentration and the amount of tar acid in the oil to be washed. For example, in the case of a 1% by weight aqueous solution of sodium hydroxide, 0.1 part by weight of 1 part by weight of the indene fraction is used. ~ 5 parts by weight,
Preferably, the proportion is 0.2 to 2 parts by weight. In general, the amount of alkali used is NaOH
In conversion, 0.005 to 0. 01 (g-NaOH / g-
Oil). The indene fraction subjected to the alkali washing treatment is subjected to a water washing treatment and, if necessary, to a distillation treatment again to obtain a product. In this case, in the water washing treatment, the use ratio of the alkali in the alkali washing treatment is small, so that the use ratio of the washing water may be small.

[0008]

According to the present invention, tar acid which acts as an interfering substance when indene is highly purified, has a polymerization preventing effect, and acts as an interfering substance when indene is used as a polymerizable monomer. An indene fraction from which the components have been substantially completely removed can be obtained easily and economically. In the present invention, by distilling the indene fraction, the high boiling point tar acid component is removed in advance, and the indene is concentrated. The advantage is that the amount of washing water used to remove alkali remaining in the indene fraction can be reduced, and the amount of wastewater by-products can be reduced accordingly. is there. Since the purified indene according to the present invention does not contain a tar acid component, it can be easily purified by distillation and can be advantageously used as a polymerizable monomer.

[0009]

Next, the present invention will be described in more detail with reference to examples. Note that the cleaning efficiency R shown below is defined by the following equation. R = A / B × 100 (%) A: amount of acid removed by alkali washing B: amount of acid before alkali washing

Example 1 Low-concentration indene oil containing 30% by weight of indene (oil A) 1
000 parts by weight using a continuous distillation column having 40 theoretical plates
Distillation was performed under a pressure of 00 mmHg at a reflux ratio of 10 to obtain 700 parts by weight of an oil (oil B) containing 43% by weight of indene from the bottom of the column. Next, this oil B was distilled at a reflux ratio of 20 under the pressure of 75 mmHg using the above distillation column to obtain 320 parts by weight of an indene concentrated oil (oil C) containing 83% by weight of indene from the top of the column.
Next, 0.75% by weight was added to 100 parts by weight of the oil C obtained above.
100 parts by weight of an aqueous sodium hydroxide solution was added, and the mixture was shake-mixed for 30 minutes, and then left to stand in a thermostat at 30 ° C. for 1 hour. Next, the oil layer was separated from the still object, and the oil layer was analyzed by gas chromatography. As a result, the washing efficiency was 100%.
In this experiment, the use ratio of alkali in the alkali washing was 0.0075 (g-NaOH / g-
Oil).

Comparative Example 1 The same operation as in Example 1 was performed by adding 100 parts by weight of a 20% by weight aqueous sodium hydroxide solution to 100 parts by weight of the oil A. The washing efficiency was 95%. In this experiment, the use ratio of the alkali in the alkali washing was 0.20 (g-NaOH / g-oil).

Example 2 Indene-containing oil (D oil) 32 containing 41% by weight of indene
00 parts by weight were collected using a batch distillation column having 15 theoretical plates.
Distillation was performed at a reflux ratio of 10 under a pressure of 0 mmHg. Distillation rate 30 to 5 containing 58% by weight of indene obtained by this distillation.
For 100 parts by weight of a 7% indene fraction (oil E), 1% by weight
The same operation as in Example 1 was performed by adding 100 parts by weight of a sodium hydroxide aqueous solution. The cleaning efficiency was 100%. In this experiment, the use ratio of the alkali in the alkali washing was 0.01 (g-NaOH / g-oil).

Comparative Example 2 An indene fraction (oil F) 10 obtained by the distillation treatment shown in Example 2 and containing 72% by weight of indene and having a distilling rate of 57 to 85% 10
0 parts by weight of a 15% by weight aqueous sodium hydroxide solution 100
The same operation as in Example 1 was performed by adding parts by weight. The cleaning efficiency was 92%. In this experiment, the use ratio of alkali in the alkali cleaning was 0.15 (g-N
aOH / g-oil).

Comparative Example 3 An indene fraction (oil G) containing 87% by weight of indene and having a distilling rate of 72 to 76%, obtained by the distillation treatment shown in Example 2 10
The same operation as in Example 1 was performed by adding 100 parts by weight of a 4% by weight aqueous sodium hydroxide solution to 0 parts by weight. The cleaning efficiency was 98%. In this experiment, the use ratio of alkali in the alkali washing was 0.04 (g-N
aOH / g-oil). Next, Table 1 shows the component composition (% by weight) in each oil described above.

[0015]

[Table 1]

Continuation of the front page (72) Inventor Shoji Komura 4-3-1 Kudankita, Chiyoda-ku, Tokyo Within Adchemco Co., Ltd. (56) References JP-A-58-180435 (JP, A) JP-A-60-87230 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C07C 13/465 C07C 7/04 C07C 7/10

Claims (1)

(57) [Claims] (I) A method obtained from coal tar distillation.
The boiling point of phenol after alkali washing of ruvol oil is higher than that of phenol.
Contains at least 0.1% by weight of a high-boiling tar acid component
Indene-containing deoxidized carbol oil or (ii) Coulter
The naphthalene oil obtained from the distillation is washed with alkali and steamed.
High boiling tar with higher boiling point than phenol obtained by distillation
Indene containing at least 0.1% by weight of acid component
A distillation step of using naphthalene gas oil as a feedstock oil and subjecting it to distillation to substantially completely remove the high-boiling tar acid component, and an alkali treating an indene-containing fraction obtained in the distillation step with an aqueous alkali solution. A washing step, wherein the alkali use ratio in the alkali washing step is NaOH
In conversion, 0.005 to 0. 01 (g-NaOH / g-
Method for producing purified indene, characterized in that an oil).