JPH0256475A - Distillation of butene oxide - Google Patents

Abstract

PURPOSE:To receiver the objective compound in a high yield by distilling butene oxide in the co-existence of an alkali metal halide when the butene oxide synthesized from an organic hydroperoxide in the presence of a molybdenum catalyst is distilled out. CONSTITUTION:When butene oxide useful as a stabilizer for chlorinated solvents or as a raw material for surfactants and glycols is distilled out from a reaction mixture solution obtained by epoxidizing a 4C olefinic compound with an organic hydroperoxide in the presence of a molybdenum catalyst, an alkali metal halide, especially extremely inexpensive and readily available sodium chloride or potassium chloride, is allowed to co-exist in the above-mentioned distillation system in an amount of at least >=0.01wt.%, preferably >=0.1wt.%, based on the reaction mixture solution to provide the objective compound in a high recovery rate of >=95% without substantially losing the objective compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for distilling butene oxide. More specifically, the present invention relates to a method of distilling and separating butene oxide synthesized from an organic hydroperoxide in the presence of a molybdenum catalyst from the synthesis liquid.

[Prior Art] The above butene oxides are epoxy compounds having 4 carbon atoms, and are important compounds as stabilizers for chlorinated solvents or as synthetic raw materials for various chemicals such as surfactants and glycols.

Conventionally, butene oxide has been synthesized from halohydrin, a corresponding olefinic compound having 4 carbon atoms, by dehydrohalogenation reaction with a basic substance such as calcium hydroxide. Furthermore, a method for synthesizing butene oxide by epoxidation reaction of an olefinic compound having 4 carbon atoms using an organic hydroperoxide as an M agent is also well known.

Distillation separation is a common method for recovering the butene oxide synthesized by the above-mentioned synthesis reaction from the reaction solution. However, in the former halohydrin method, since water and butene oxide form an azeotropic mixture, water is separated by azeotropic distillation along with other suitable azeotropic agents, and then the target product is distilled. need to be separated. on the other hand,
Regarding the latter epoxy compound obtained by oxidation with an organic hydroperoxide, the target compound can be separated by direct distillation separation from the reaction solution.

The process of producing butene oxide through epoxidation reaction with the organic hydroperoxide described above not only does not produce large amounts of by-products of alkali or alkaline earth metal salts of halogens, which have almost no value, as in the halohydrin process, but also does not require the distillation process. It also has the advantage of being very simple.

Therefore, in JP-A-56-133279, Mo, V
A method of synthesizing an olefinic compound by an epoxidation reaction with an organic hydroperoxide using an organometallic compound of a metal selected from
No. 7453 proposes a method for synthesizing butene oxide by an epoxidation reaction using an organic hydroperoxide catalyzed by metallic molybdenum, which is substantially insoluble under the reaction conditions.

[Problem to be solved by the invention]

Distillation is the simplest method for separating butene oxide synthesized from organic hydroperoxide from the synthesis reaction solution. A light boiling fraction whose main component is an unreacted raw material olefin, which usually has 4 carbon atoms, Next, butene oxide, which is the target product, is obtained as a main fraction, and the remainder becomes a bottom residue.

However, if it is attempted to obtain butene oxide directly from the reaction mixture by distillation in this way, the total weight of butene oxide in each fraction including the bottoms of distillation will be less than the weight of butene oxide charged. That is, there has been a problem in the reduction of butene oxide, which is thought to be due to thermal history and the like during distillation operations.

[Means to solve the problem]

The present inventors have conducted intensive studies on the above-mentioned problems in separating butene oxide synthesized by organic hydroperoxide in the presence of a molybdenum catalyst from the synthesis reaction solution, and have found that, quite unexpectedly, the main distillation The present inventors have discovered that butene oxide can be recovered by distillation at an extremely high rate if this process is carried out in the coexistence of an alkali metal halide, leading to the completion of the present invention. That is, the method for distilling butene oxide of the present invention involves distilling and separating butene oxide from a reaction solution obtained by converting an olefinic compound having 4 carbon atoms into a corresponding epoxy compound with organic hydroperoxide in the presence of a molybdenum catalyst. , which is characterized by distillation in the coexistence of an alkali metal halide.

The olefinic compounds having 4 carbon atoms in the present invention are °, 1-butene, trans-2-butene, cis-
It is a general term for 2-butene and isobutylene, and may be one type or a mixture of two or more of these groups. Therefore, the epoxy compounds corresponding to these are 1,2-butene oxide, trans-2-butene oxide, cis-2-butene oxide, and isobutylene oxide, and one type or a mixture of two or more from these groups. There may be.

Examples of organic hydroperoxides used as epoxidizing agents in the present invention include cumene hydroperoxide, ethylbenzene hydroperoxide, and tert-
Butyl hydroperoxide and the like are relatively easily available industrially and are often used. These organic hydroperoxides usually contain hydrocarbon precursors, which serve as solvents. Therefore, using any of these organic hydroperoxides,
When an olefinic compound having 4 carbon atoms is epoxidized, the synthesis reaction solution contains at least unreacted raw material olefin,
For reaction with the target epoxy compound, alcohol compound derived from organic hydroperoxide, hydrocarbons contained in organic hydroperoxide, unreacted residual organic hydroperoxide, and other cleavage products from organic hydroperoxide. It is obtained as a mixture of the used catalysts, etc.

As a homogeneous catalyst used for the epoxidation reaction in the present invention, an organometallic compound of a metal selected from MO1 and W is known to be effective.
For example, organometallic molybdenum compounds such as molybdenum naphthinate, stearate, octoate, carbonyl complex, and acetylacetonate are preferably used.

Also, as shown in Japanese Patent Application No. 6,347,453, metallic molybdenum, which is substantially insoluble under the reaction conditions, can also be used as a catalyst.

Therefore, when a homogeneous molybdenum catalyst is used, the catalyst is directly carried into the distillation process, and butene oxide is distilled and separated from the reaction mixture containing the catalyst and many of the compounds mentioned above. In addition, when metallic molybdenum, which is substantially insoluble, is used as a catalyst, after the epoxidation reaction is completed, molybdenum is separated from the reaction mixture by static separation and/or filtration. Distill butene oxide.

After distilling off the light-boiling fraction from this reaction mixture, the target butene oxide is distilled out, and the total recovered butene oxide in each fraction after distillation is less than 90%, or even worse, less than 80%. In this case, the total weight, that is, the weight recovery rate of the distillate fraction and the pot residue, was over 95%, so the butene oxide vapor was insufficiently condensed during the distillation operation and was dissipated outside the distillation system. Rather, it seems that the butene oxide has changed into some other compound due to heat history, for example.

Moreover, most of the causes of the decrease in weight recovery rate are unreacted raw material olefins having a low boiling point and having 4 carbon atoms.

Although this decrease in weight recovery rate varies in degree, it is a common problem not only in distillation operations but also in heating operations of synthesis reaction mixtures containing butene oxide epoxidized with organic hydroperoxide in the presence of molybdenum catalysts. However, by carrying out the distillation operation of the present invention in the coexistence of an alkali metal halide, even in a batch distillation operation in which the total recovery rate of butene oxide is 90% or less, the reaction mixture Butene oxide can be obtained with almost no loss at a high recovery rate of 95% or more.

The alkali metal halide used in the present invention is
These are fluorides, chlorides, bromides, and iodides of lithium, sodium, potassium, rubidium, and cesium. Typical compounds that can be used include lithium fluoride, lithium chloride, sodium fluoride, sodium chloride, sodium bromide,
Examples include sodium iodide, potassium chloride, potassium bromide, potassium iodide, and cesium chloride. Among these, particularly effective are alkali metal salts such as sodium chloride and potassium chloride, which are available at extremely low cost and in large quantities.

The individually listed alkali metal halides are substantially insoluble in the synthesis reaction product solution containing the epoxy compound in the present invention, and by allowing them to coexist at least in the heated liquid part during the distillation operation. The purpose of the present invention can be achieved.

The alkali metal halide is at least 0.0% of the reaction mixture being heated. It is sufficient that the coexistence is at least 0.1% by weight, preferably at least 0.11% by weight.Although there is no particular restriction on the upper limit, it is added at least 5% by weight since it is substantially insoluble in the reaction mixture to be distilled. This results in a slurry, which causes problems with operability in the process.

〔Example〕

Hereinafter, the effects of the present invention will be explained in more detail with reference to Examples.

Example 1 Isobutylene was reacted with cumene hydroperoxide in the presence of molybdenum oxide acetylacetonate in a cumene solvent to form isobutylene oxide, and a synthesis reaction solution having the following composition was obtained.

Isobutylene: 4.2% by weight Isobutylene oxide: 16.5% by weight Cumene
: 36.7% by weight Dimethylphenyl carbinol: 38.5% by weight α-methylstyrene: 1.5% by weight Others
: 2.6% by weight 1.5g of sodium chloride was added to 300g of this reaction solution, and a batch was prepared using a packed column (201φ x 40hd) filled with a 1.8-φ Heli Pack (HELI PACK No. 1, manufactured by Tokyo Tokushu Kinami ■). It was distilled. 5.5 g of the fraction (Fraction-I) with a tower top pressure cuff of 45 mmHg and a tower top temperature of up to 44°C, 44”C or higher 4965
43.5 g of a fraction (fraction -■) was obtained, and 240.9 g was recovered as a bottom liquid. Isobutylene oxide (hereinafter referred to as 1-BO) in fraction -■ il 11 degrees is 5
It was 1.7% by weight. In addition, I in the distillate - ■ and in the bottom of the pot
-Bo'a degree was 96.9% by weight and 0.9% by weight, respectively. That is, the total 1-BO recovery rate in the main distillation with respect to the charged I-BO was 95.3%. Further, the total recovery rate of the distillation charge, the fraction-L fraction-■ recovered by distillation, and the recovered pot residue was 96.6%. The results are shown in Table-1.

Comparative Example-1 In Example 1, everything was carried out in the same manner as in Example-1 except that sodium chloride was not added.
-The recovery rate of BO was as low as 82.3%. Table 1 shows the results.
Shown below.

Examples 2 to 10 Distillation was carried out in the same manner as in Example 1, except that the alkali metal halides shown in Table 1 were added in place of sodium chloride. In all cases, the recovery rate of I-BO was good. The results are shown in Table-1.

[Effects of the Invention] In the present invention, when extracting a distillate from a reaction mixture containing butene oxide synthesized with an organic hydroperoxide in the presence of a molybdenum catalyst, only a very small amount of an alkali metal halide is allowed to coexist. Butene oxide can be recovered at a high rate, and extremely beneficial effects can be obtained in operations that must be performed during industrial production.

Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] When distilling butene oxide from a reaction solution obtained from an olefinic compound having 4 carbon atoms as a corresponding epoxy compound with an organic hydroperoxide in the presence of a molybdenum catalyst, it is distilled in the presence of an alkali metal halide. A method for distilling butene oxide, characterized by: