JPS6023090B2 - Liquid phase oxidation method of aliphatic hydrocarbons - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to aliphatic hydrocarbons (hereinafter referred to as paraffins) containing aromatic hydrocarbons.

) in the presence of a boron compound in a liquid phase with a molecular state element-containing gas. To be more specific, the present invention involves the coexistence of at least one selected from ammoniacal bases with ozone when paraffins containing aromatic hydrocarbons are oxidized in a liquid phase with a molecular oxygen-containing gas in the presence of a boron compound. The following relates to a method for producing corresponding alcohols by carrying out an oxidation reaction. As one of the typical industrial methods for producing alcohols from paraffins, a method of liquid phase oxidation using molecular oxygen-containing gas in the presence of paraffins and a boron compound is known. Conventionally, in the liquid phase oxidation method of paraffins with a molecular oxygen-containing gas in the presence of a boron compound (hereinafter referred to as the boric acid oxidation method), the boron compound acts as a catalyst to increase selectivity to alcohol, and at the same time, It is known to have the effect of suppressing autoxidation reactions, and on the other hand, aromatic hydrocarbons contained in paraffin as impurities are also known to act as substances that interfere with the oxidation reaction of paraffins in the presence of boron compounds. ing. Therefore, in boric acid oxidation, when a boron compound and aromatic hydrocarbons coexist in the reaction system, they exhibit a mutual effect and become an extremely strong oxidation reaction inhibitor. If this oxidation reaction inhibiting effect cannot be removed, the oxidation reaction will not occur at all, or it will be impossible to continue the oxidation reaction. However, in the boric acid oxidation method,
The presence of boron compounds not only improves the selectivity to alcohol, but also stabilizes the produced alcohol by converting it into boric acid ester, thereby preventing the sequential oxidation of alcohol. It is essential in the alcohol synthesis reaction.

In general, methods to solve the above problems include using paraffins containing less aromatic hydrocarbons,
A method of carrying out boric acid oxidation by reducing the amount of boron compound has been proposed, as disclosed in Japanese Patent Publication No. 45-327.

However, in the boric acid oxidation method, the amount of boron compound is closely related to the selectivity of the alcohol produced, so usually
The boron compound needs to have a volume of at least 1.3 equivalents necessary to form an orthoborate ester with the produced alcohol,
If the amount is less than that, especially if the amount is less than 1.2 times, the selectivity to alcohol decreases. Therefore, a more fundamental solution is required to industrially establish a method for carrying out an oxidation reaction in the presence of an optimal boron compound using paraffin having a high content of aromatic hydrocarbons. On the other hand, in the boric acid oxidation method, additives other than boron compounds are added as promoters to improve the reaction rate and yield, such as peroxides, heavy metal compounds, ozone, alkali metal compounds, and alkali metal compounds. Various proposals have been made regarding the addition of easily oxidizable organic compounds and the like. However, these promoters do not have the effect of eliminating the oxidation reaction interfering effect of aromatic hydrocarbons in the reaction system in the boric acid oxidation method. Further, in the specification of Japanese Patent Publication No. 44-26281, the addition of ammoniacal bases as a co-catalyst is proposed. However, in the boric acid oxidation method, this method is effective in eliminating the oxidation reaction interference only when the content of aromatic hydrocarbons in the reaction system is relatively small; If the concentration becomes too large, the effect will not be exhibited. In the boric acid oxidation method, the present inventors conducted intensive research to eliminate the oxidation reaction interfering effect of aromatic hydrocarbons in the reaction system. The present invention was completed based on the finding that the coexistence of aromatic hydrocarbons has a remarkable effect in eliminating the interference with the oxidation reaction of aromatic hydrocarbons.

Therefore, the present invention provides a method for liquid-phase oxidation of aliphatic hydrocarbons containing aromatic hydrocarbons at an unprecedentedly high concentration with a molecular oxygen-containing gas in the presence of a boron compound. This is a liquid-phase oxidation method for aliphatic hydrocarbons containing aromatic hydrocarbons, which is characterized by carrying out an oxidation reaction in the coexistence of at least one type of aromatic hydrocarbons and ozone. According to the present invention, as shown in FIG. 1 below,
For example, in a boric acid oxidation method using paraffin with an aromatic hydrocarbon concentration of 0.04% by weight, if ammonia or ozone is added individually to the reaction system and the oxidation reaction is carried out, the oxidation reaction will not occur at all. On the other hand, when the oxidation reaction is carried out in the presence of ammonia and ozone in the reaction system, the interfering effect of the aromatic hydrocarbons on the oxidation reaction is eliminated and the reaction proceeds normally.

Further, by applying the method of the present invention, it has become possible to use paraffins containing large amounts of aromatic hydrocarbons, which were previously considered unusable industrially as raw materials for boric acid oxidation.

Generally, in the boric acid oxidation method, the normal pass (Pass)
It is said that an economical conversion rate of paraffins is in the range of 10 to 30%.

Therefore, the raw materials used in the present invention, the paraffins co-fed to the reaction system, are separated from alcohols by distillation etc. after the oxidation reaction and new paraffins equal to the amount consumed in the reaction. It is a mixture with recovered paraffins that has been pre-processed so that it can be used for other purposes. These paraffins have 6 to 6 carbon atoms.
30 n-paraffins and ISO-paraffins, in particular when paraffins having 8 to 20 carbon atoms are used, the corresponding alcohols based on sec-alcohols can be obtained in high yields. The concentration of aromatic hydrocarbons in the paraffin used in the present invention is suitably 1% by weight or less, preferably in the range of 1 to 0.001% by weight.

If the amount is 0.001% by weight or less, the boric acid oxidation reaction can be carried out without using the method of the present invention.

The boron compounds used in the present invention include orthoboric acid,
At least one selected from metaboric acid, boron oxide, and boric acid esters is used, and metaboric acid is particularly preferred.

Further, the boron compound used has an amount of boron of 1 mole or more per 3 moles of alcohol produced in the oxidation reaction. Particularly preferred is the presence of 1.5 to 3 moles. The ammoniacal base used in the present invention is at least one selected from ammonia, amines, nitrogen-containing double cyclic bases, or salts thereof. Typical examples include ammonia, methylamine, ethylamine, propylamine, isopropylamine, butylamine, dimethylamine, diethylamine, dipropylamine, diisopropylamine, trimethylamine, triethylamine, tripropylamine,
Triisopropylamine, ethylenediamine, allylamine, ethyleneimine, propyleneimine, ethanolamines, propanolamines, choline, hydrazine, methylhydrazine, formamide, acetamide, acetohydrazide, glycine, alanine, pyrrole, triazole, tetrazole, piverizine, pyridine, Piverazine, triazine, tetrazine, indole, quinoline, carbazole, ammonium carbonate, ammonium acetate, ammonium borate, urea, thiourea, etc., and the amount used is 0.0001 to 1 mol, especially 0.001 to 1 mol, per 1 mol of boron atom. A range of 0.001 to 0.1 mol gives preferable results. Ozone is 0.001 to 10 mol, especially 0.01 mol per gram of aromatic hydrocarbons mixed in raw materials.
~1 mole gives favorable results.

As a method for supplying these ammoniacal bases and ozone into the reaction system, the ammoniacal bases and ozone may be supplied into the reaction system separately or as a mixture.

Taking advantage of their physical properties, ammonia bases can be dissolved or suspended in paraffins, adsorbed or mixed with boron compounds, or entrained in blowing gas. , is continuously or continuously supplied to the reaction system. Additionally, ozone is usually preferably entrained in the blowing gas. The oxygen concentration in the blow gas can be varied within a wide range, but a range of 2 to 8% by volume gives particularly good results.

The rest is inert gas such as nitrogen and carbon dioxide. The amount of blown gas is related to the type of reactor, but the volume ratio is preferably 1 to 50, particularly 3 to 30 per minute per raw material. In the present invention, the reaction can be carried out in a batch, semi-batch or continuous manner.

The reaction temperature is 130~200℃, especially 150~180q
o is preferred. In addition, the reaction pressure can be either normal pressure or elevated pressure, and the boiling point of the paraffin raw material,
It may be selected appropriately taking into consideration the reaction temperature, oxygen partial pressure, etc. Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not limited only to the Examples.

In addition, the conversion rate and selectivity in the examples shall be in accordance with the following definitions. Conversion rate (%) = number of moles of paraffin supplied - number of moles of unreacted paraffin X. 〇Selectivity (%) of moles of paraffin supplied = consumed and produced≦≧table
Poisonous damage No. of poisonous coatings
100 tons of mixed n-paraffin containing 12, 13, and 14 carbon atoms were placed in a glass cylindrical reactor equipped with a reflux condenser and a moisture container, and 3.5 tons of metaboric acid was added thereto, followed by blowing gas. As ozone 0.1% by volume, ammonia 0.01% by volume, oxygen 4. Existing capacity %, nitrogen 95
．． A mixed gas of volume % is blown in at a rate of 0.7 per minute,
The reaction was carried out at a temperature of 17,000 for 2 hours.

After the reaction was completed, the reaction solution was hydrolyzed with hot water, and the resulting oil layer containing alcohols with a corresponding number of carbon atoms was subjected to chemical analysis and gas chromatography analysis. The results were as shown in Table 11. Incidentally, FIG. 1 shows the relationship between the concentration of aromatic hydrocarbons in the paraffin supplied and the conversion rate of paraffin.

Table 1 Comparative Example 1 Using a mixed n-paraffin containing aromatic hydrocarbons at the concentrations shown in Table 2 and having an average molecular weight of 185 and consisting of 12, 13 and 14 carbon atoms, 5.0% of oxygen was used as the blowing gas. The reaction was carried out under the same conditions as in Example 1, except that a mixed gas having a composition of 95.0% by volume and 95.0% by volume of nitrogen was used.

The results were as shown in Table-2. FIG. 1 shows the relationship between the concentration of aromatic hydrocarbons in the paraffin supplied and the conversion rate of paraffin. Table 2 Comparative Example 2 Using a mixed n-paraffin containing aromatic hydrocarbons at the concentrations shown in Table 3 and having an average molecular weight of 185 and consisting of 12, 13 and 14 carbon atoms, ozone was used as the blowing gas at 0.1
% by volume, 4.9% by volume of oxygen, 95% by volume of nitrogen. The reaction was carried out under the same conditions as in Example 1 except that a mixed gas having a composition of % by volume was used.

The results were as shown in Table-3. Table 3 Comparative Example 3 Using a mixed n-paraffin containing aromatic hydrocarbons at the concentrations shown in Table 4 and having an average molecular weight of 185 and consisting of 12, 13 and 14 carbon atoms, 0 ammonia was used as the blowing gas.
．． 01% by volume, oxygen 5. Crab volume%, nitrogen 95.0 volume%
The reaction was carried out under the same conditions as in Example 1 except for using a mixed gas of .

The results are shown in Table-4. FIG. 1 shows the relationship between the concentration of aromatic hydrocarbons in the paraffin supplied and the conversion rate of paraffin. Table 4 Examples 2 to 7 Average molecular weight 18 containing 0.0 box weight% of aromatic hydrocarbons
Mixed n- with 5 and 12, 13 and 14 carbon atoms
100 ml of paraffin was placed in a glass cylindrical reactor, 3.5 ml of metaboric acid and various ammonia bases shown in Table 5 were added, and 0.1% by volume of ozone was added as a blowing gas.
A mixed gas consisting of 4.9% by volume of oxygen and 95.0% by volume of nitrogen was blown in at a rate of 0.7% per minute at a temperature of 170q.
The reaction was carried out at C for 2 hours.

After the reaction was completed, the reaction solution was hydrolyzed with hot water, and the resulting oil layer containing alcohols with a corresponding number of carbon atoms was subjected to chemical analysis and gas chromatography analysis. The results were as shown in Table-5. Table-5 Example 8 Average molecular weight 18 containing 0.32% by weight of aromatic hydrocarbons
Mixed n- with 5 and 12, 13 and 14 carbon atoms
100 μm of paraffin was placed in a glass cylindrical reactor, 1.5 μm of metaboric acid and 0.0 μm of ozone were added. A mixed gas consisting of 0.02% by volume of ammonia, 6.7% by volume of oxygen, and 93.0% by volume of nitrogen was blown in at a rate of 0.7% per minute and reacted for 1 hour at a temperature of 170oo. .

After the reaction was completed, the reaction solution was hydrolyzed with hot water, and the resulting oil layer containing alcohols with a corresponding number of carbon atoms was subjected to chemical analysis and gas chromatography analysis. The results were as shown in Table-6.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between the aromatic hydrocarbon concentration in paraffin feedstock and the conversion rate of paraffin.
1 is when the blown gas has no additives, 2 is when ozone is 0.
When 1% by volume of ammonia is added, 3 represents the case when 0.01% by volume of ammonia is added, and 4 represents the case when 0.1% by volume of ozone and 0.01% by volume of ammonia are added. Figure 1

Claims (1)

[Claims] 1. When producing the corresponding alcohol by liquid-phase oxidation of aliphatic hydrocarbons containing 10% by weight or less of aromatic hydrocarbons with molecular oxygen-containing gas in the presence of a boron compound, ammoniacal bases A liquid phase oxidation method for aliphatic hydrocarbons, characterized by carrying out an oxidation reaction in the coexistence of at least one selected from the following and ozone.