JP2012131730A - Method of producing vinyl chloride monomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce a vinyl chloride monomer under lower temperature and lower pressure condition.SOLUTION: In a method of producing the vinyl chloride monomer, 1,2-dichloroethane is subjected to dehydrochlorination through catalytic reaction made by solid acid catalyst to produce the vinyl chloride monomer. For example, a solid catalyst, such as γ-alumina and silica alumina, that shows Lewis acidity is suitably used as the solid acid catalyst.

Description

  The present invention relates to a method for producing a vinyl chloride monomer.

Polyvinyl chloride resin is excellent in mechanical strength, chemical resistance, and the like, and has been conventionally used for various applications such as piping materials and building materials.
The vinyl chloride monomer, which is a raw material for producing this polyvinyl chloride resin, has been conventionally produced by thermally decomposing 1,2-dichloroethane synthesized by a direct chlorination method or oxychlorination method of ethylene (patent document). 1-3).

JP-A-5-262682 JP-A-6-80593 WO2006 / 098466

  However, these thermal decomposition reactions require high-temperature and high-pressure conditions of 500 ° C. and 15 atmospheres in order to obtain sufficient reaction efficiency, which requires high-performance equipment and complicated control of conditions. There were problems such as being said.

  This invention is made | formed in view of the said subject, and it aims at providing the manufacturing method of the vinyl chloride monomer which can manufacture a vinyl chloride monomer efficiently at lower temperature and / or low pressure.

The method for producing the vinyl chloride monomer of the present invention comprises:
It is characterized by producing 1,2-dichloroethane by dehydrochlorination by a catalytic reaction with a solid acid catalyst.
In such a method for producing a vinyl chloride monomer,
Using the solid acid catalyst exhibiting Lewis acidity,
The solid acid catalyst showing Lewis acidity is γ-alumina,
The solid acid catalyst exhibiting Lewis acidity is silica alumina,
Whether the silica alumina has a silica / alumina ratio of 0.5-20,
It is preferable to include any one or more of setting the reaction temperature to 300 to 400 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a vinyl chloride monomer which can manufacture a vinyl chloride monomer efficiently in lower temperature / low pressure can be provided.

In the method for producing a vinyl chloride monomer of the present invention, 1,2-dichloroethane can be produced by dehydrochlorination by a catalytic reaction with a solid acid catalyst.
1,2-dichloroethane itself can be produced by any conventionally known method. For example, it can be obtained by direct chlorination or oxychlorination of ethylene.
The purity of 1,2-dichloroethane used is not particularly limited, and those produced by known methods may be used as they are without purification. Moreover, from a viewpoint of manufacturing a vinyl chloride monomer efficiently, Preferably it is 80-100 wt%, More preferably, a 90-100 wt% thing is mentioned.

  1,2-Dichloroethane may be either a gas or a liquid during the reaction, but the dehydrochlorination reaction of 1,2-dichloroethane is usually carried out in the gas phase, so it is suitable for use as a gas. . For example, it is preferable to use 1,2-dichloroethane vaporized by a vaporizer. In addition, 1,2-dichloroethane may be used without being diluted, or may be used after being diluted with an inert gas or the like. Although it does not specifically limit as an inert gas used for dilution, For example, nitrogen, helium, argon etc. are mentioned. These inert gases can be used alone or in admixture of two or more. The degree of dilution is not particularly limited.

  The solid acid catalyst is not particularly limited, and any known in the art may be used. For example, metal salts such as halides, sulfates, phosphates, oxides, sulfides; isopolyacids, heteropolyacids, complex oxides, immobilized sulfonic acids, zeolites (amicite, ammonium leucite, fluorite, barrels Zeolite, bellbergite, bikitaite, boggsite, brewsterite, brewsterite-Sr, brewsterite-Ba, chabazite, chalybazite, soda chabazite, potash, chaavennite, clinoptilolite (-Na, -K, -Ca, etc.), Courusite, Dakiardiite, Ashdakiardiite, Sodadakiardiite, Eddingtonite, Exfoliated stone, Elionite, Soda Elionite, Cullionionite, Ash Elionite, faujasite (-Na, -Ca, -Mg, etc.), Ferrierite (-Mg, -K, -Na, etc.), Gallonite, gaultite, Gismondite, Gumelinite (-Na, -Ca, -K, etc.), Gobbinsite, Gonaldite, goosecreekite, gottardiite, heavy soil Agarite, pyroxene, perovite, strontium pyroxene, soda pyroxene, potassium pyroxenite, hsianghualite, kalborsite, aragonite, white nepheline, levite (-Ca, -Na, etc.), lovdarite, maricopaite, mazzite, merlinoite, mesolite, montesommaite, mordenite, mutinaite, soda zeolite, offretite, pahasapaite, partheite, paulingite (-K, -Ca etc.), zeolitic (-Na, -K, -Ca etc.), polxite, roggianite, scholes Zeolite, stellar zeolite, bundle zeolite (-Ca, -Na, etc.), Thomson zeolite, tschernichite, tschortnerite, Weirake zeolite, weinebeneite, willhendersonite, Yugawara zeolite, etc.) and those with adsorbed hydrogen ions at the cation exchange sites of these zeolites Can be used. You may use these individually or in combination of 2 or more types.

Among them, those showing Lewis acidity are suitable. Moreover, since it can obtain easily, an alumina, a silica alumina, or a zeolite is preferable. As the zeolite, the largest pore structure is desirably an oxygen 12-membered ring, and among them, mordenite, beta zeolite, Y-type zeolite and the like are more preferable.
When silica alumina or zeolite is used as the solid acid catalyst, the silica / alumina ratio is suitably 0.5 to 20, preferably 0.5 to 10.
As long as it corresponds to the above, what was synthesize | combined by synthesis methods, such as normal hydrothermal synthesis, a precipitation method, and a coprecipitation method, a commercial item, etc. can be used for a solid acid catalyst.

  The solid catalyst may be used as it is, or may be used by supporting it on a suitable carrier such as silica. The shape of the catalyst can be any shape and size such as granular, pellet, cylindrical.

  In the method for producing a vinyl chloride monomer of the present invention, the reaction form is not particularly limited, and can be carried out in any reaction form. For example, fixed bed type (for example, fixed bed gas phase flow type, fixed bed liquid phase flow type), fluidized bed type (for example, fluid bed gas phase flow type, fluid bed liquid phase flow type), suspension bed batch type, A facility that can realize a suspension bed continuous type and the like can be mentioned. Among these, a fixed bed gas phase flow method, a fixed bed liquid phase flow method, and a suspension bed batch method are suitable.

The reaction temperature is suitably about 300 to 400 ° C.
The LHSV value in the reaction is preferably from 0.2 to 10, more preferably from 0.5 to 5. The LHSV value can be determined by dividing the weight (g) of 1,2-dichloroethane reacted per hour by the catalyst volume (ml).

  The dehydrochlorination reaction of 1,2-dichloroethane may be performed under normal pressure or under pressure. For example, normal pressure (≈0.1011325 MPa) to about 2.0 MPa, preferably about 0.1 to 0.8 MPa. Thereby, a side reaction can be reduced. The dehydrochlorination reaction may be performed in the air or in an oxygen atmosphere. However, when the above-described dilution gas is used, it is suitable to perform in an inert gas, for example, a nitrogen or argon atmosphere.

The supply amount or supply rate of 1,2-dichloroethane to the reaction system can be appropriately adjusted depending on, for example, the volume, temperature, pressure, etc. of the catalyst. For example, in either case of supplying in liquid and gas, about 0.1 to 10 g / hour is mentioned.
The vinyl chloride monomer obtained by the reaction can be recovered by methods known in the art and may be further purified. For example, a method such as liquefaction separation of by-products by cooling is exemplified.

Below, the Example of the manufacturing method of the vinyl chloride monomer of this invention is shown concretely.
The dehydration reaction of 1,2-dichloroethane was performed using a flow-type catalytic reactor, and the catalyst was filled in a quartz straight tube (inner diameter 10 mm).
Reaction gas and reaction liquid are gas chromatograph (manufactured by Shimadzu Corporation, trade name GC-2010), capillary column (manufactured by Agilent J & W, trade name DB-1, 30 m × 0.25 mm (inner diameter), film thickness 1.0 μm) hydrogen Quantification was performed using a flame ionization detector (FID).

The 1,2-dichloroethane conversion rate and vinyl chloride monomer selectivity were calculated by the following equations.
1,2-dichloroethane conversion (%) = {(feed 1,2-dichloroethane amount (mol) -detected 1,2-dichloroethane amount (mol)) / feed 1,2-dichloroethane amount (mol)} × 100
Vinyl chloride monomer selectivity (%) = {vinyl chloride monomer amount (mol) / (each product amount (mol) × carbon number / 2)} × 100

Example 1
A quartz reaction tube having an inner diameter of 10 mm was filled with 3 g of γ-alumina and heat-treated at 400 ° C. for 2 hours in nitrogen. Thereafter, the solid acid catalyst was allowed to cool to the reaction temperature to obtain a catalyst layer.
The vaporized 1,2-dichloroethane was passed through the catalyst layer at a flow rate of 0.6 g / hour and a nitrogen flow rate of 8000 ml / hour, and reacted under conditions of a pressure of 0.1 MPa and a reaction temperature of 360 ° C. The LHSV value for this reaction was 2.8.
When the reaction product was analyzed by gas chromatography, the 1,2-dichloroethane conversion was 70% and the vinyl chloride monomer selectivity was 82% after 1 hour of the reaction elapsed time.

Example 2
The reaction was performed in the same manner as in Example 1 except that silica alumina having a silica / alumina ratio of 7 was used instead of γ-alumina.
When the reaction product was analyzed by gas chromatography, 1,2-dichloroethane conversion was 65% and vinyl chloride monomer selectivity was 80% after an elapsed time of reaction of 1 hour.

Example 3
The reaction was conducted in the same manner as in Example 1 except that hydrogen type Y zeolite with a silica / alumina ratio of 15 was used.
As a result of analyzing the reaction product by gas chromatography, 1,2-dichloroethane conversion was 63% and vinyl chloride monomer selectivity was 75% after 1 hour of reaction elapsed time.

  According to the present invention, a vinyl chloride monomer can be efficiently produced at a lower temperature / lower pressure.

Claims (6)

  A method for producing a vinyl chloride monomer, characterized in that 1,2-dichloroethane is produced by dehydrochlorination by a catalytic reaction with a solid acid catalyst.   The method for producing a vinyl chloride monomer according to claim 1, wherein the solid acid catalyst exhibiting Lewis acidity is used.   The method for producing a vinyl chloride monomer according to claim 2, wherein the solid acid catalyst exhibiting Lewis acidity is γ-alumina.   The method for producing a vinyl chloride monomer according to claim 2, wherein the solid acid catalyst exhibiting Lewis acidity is silica alumina.   The method for producing a vinyl chloride monomer according to claim 4, wherein the silica alumina has a silica / alumina ratio of 0.5 to 20.   The method for producing a vinyl chloride monomer according to claim 1, wherein the reaction temperature is 300 to 400 ° C.