JPS6241577B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oxyhalogenation method using a fluidized bed, particularly to an oxyhalogenation method suitably used for producing 1,2-dichloroethane from ethylene. Specifically, the present invention provides an oxyhalogenation method in which side reactions, particularly the production of carbon monoxide or carbon dioxide gas due to fuel reactions, are suppressed while maintaining a stable fluidization state by using a specific fluidization aid. Oxyhalogenation methods using fluidized beds are conventionally known. For example, 1,2-dichloroethane is produced on an industrial scale by carrying out oxychlorination of ethylene in a fluidized bed using an oxyhalogenation catalyst in which cupric chloride is supported on an alumina carrier. In this oxyhalogenation reaction using a fluidized bed, it is extremely important to maintain a good fluidity state during the reaction, and if the fluidity state deteriorates, the reaction yield will drop significantly.
Various measures have been proposed to maintain a good fluidity state, among which it is particularly desirable to add fluidization aids. For example, in Japanese Patent Publication No. 53-24045, glass beads, silica sand, α-alumina It has been shown that 50 to 95% by weight of fluidization aids, such as particles, are added to the particles of the entire fluidized bed. However, the particles shown in Japanese Patent Publication No. 53-24045 do not have pores inside and have smooth surfaces, so the particle density is close to the true density, and it is almost
It is in the range of 2.2 to 3.9 g/cm ³ . Even if a flow aid having such a particle density is used in the case of an oxyhalogenation catalyst, the most typical of which is a catalyst in which cupric chloride is supported on an alumina carrier, no significant improvement in the flow effect can be expected. The reason is that the density of catalyst particles
This is because the density of the flow aid is too large compared to 1.5 g/cm ³ , making it impossible to maintain a good flow state. Although the fluidity state can be improved by increasing the amount of fluidization aid added, there are disadvantages in that as the amount of fluidization aid added increases, the reaction rate decreases and the size of the reaction apparatus increases. On the other hand, the reaction rate can be improved by increasing the amount of catalyst supported on the carrier, but as the amount supported increases, the agglomeration of catalyst particles increases, causing a blow-through phenomenon and deteriorating the flow state. From this point of view, the amount of catalyst supported is limited. Therefore, in order to maintain a good fluidity state between the catalyst particles and the fluidization aid, it is conceivable to use a fluidization aid whose density is about the same as that of the catalyst particles. Common sense suggests that the particles used as catalyst carriers should be used as fluidization aids, and from this point of view, alumina, which is a typical catalyst carrier for oxyhalogenation catalysts,
Silica and the like are preferred. In fact, according to experiments conducted by the present inventors, the flow additive made of alumina is
It was confirmed that a good fluidization state could be obtained using catalyst particles in which cupric chloride was supported on an alumina carrier and a fluidized bed. In particular, even in cases where water is produced as a by-product, such as in the oxychlorination reaction of ethylene, the catalyst particles do not aggregate and the fluidity is good. The reason for this is not clear, but it is thought that the porous nature of the alumina particles adsorbs the generated water, thereby improving the fluidity.
However, apart from these advantages, new problems have arisen. That is, a large amount of carbon monoxide or carbon gas is produced due to side reactions, especially combustion reactions. As a result of various studies on the causes of the above side reactions, the present inventors found that the side reactions are related to the acid sites of alumina, and that when using alumina whose acid sites have been made basic and neutralized, the fluidity state It has been found that side reactions can be suppressed while maintaining good quality. Based on this knowledge, it was confirmed that similar results could be obtained by pre-basifying silica and silica-alumina to neutralize the acid sites in addition to alumina, leading to the completion of the present invention. Ivy. The present invention uses particles selected from basified alumina, silica, and silica-alumina as a fluidization aid in a method for oxyhalogenating hydrocarbons or halogenated hydrocarbons in a fluidized bed in the presence of a catalyst. This is an oxyhalogenation method characterized by using at least one kind. In the present invention, known methods can be used as they are for oxyhalogenating hydrocarbons or halogenated hydrocarbons using a fluidized bed. As hydrocarbons or halogenated hydrocarbons,
May be saturated or unsaturated, e.g. methane,
Ethane, propane, butane, ethylene, propylene, 1-butene, chloroethane, 1,2-dichloroethane, etc. are used, and mixtures thereof may also be used. In addition, the main components of the oxyhalogenation catalyst include copper chloride, iron chloride, silver chloride, lead chloride, platinum chloride, gold chloride, ruthenium chloride, chromium chloride, etc., and supplementary components such as potassium chloride, sodium chloride, and chloride. A suitable combination of chlorides such as magnesium and cesium chloride, supported on a carrier, is generally used. Alumina, silica, silica-alumina, zeolite, activated carbon, acid clay, pumice, etc. are known as carriers; Alumina, silica, or materials based on these materials, which have special characteristics, are used. In addition, alumina, which was previously proposed by the present inventors,
An acidic carrier such as silica is treated with an alkali to make it basic as defined below, in particular, a carrier made basic with Hammett's acid strength function H _p of 12 or more is supported with a catalyst component, and this is made basic. It is preferable to use an oxyhalogenation catalyst which has been made basic by oxidation, since this further suppresses the combustion reaction. A method is adopted in which the catalyst particles and the fluidization aid are made to flow using the raw material gas using a perforated plate, a bubble cap, etc. as a dispersion plate, or a lattice-shaped pipe with holes made therein. It is also preferable to provide a cyclone above the fluidized bed in order to prevent the catalyst particles from scattering out of the fluidized bed along with the reaction gas. Furthermore, if the diameter of the fluidized bed is large, it is preferable to install a multitubular pipe inside and control the temperature by passing a heat medium through the pipe. In the present invention, when performing an oxyhalogenation reaction using the above-mentioned raw material components, an oxyhalogenation catalyst, and a fluidized bed, alumina, silica, and silica-alumina that have been made basic are used as fluidization aids. It is characterized by the use of at least one type of particles. As the alumina, activated alumina such as γ-alumina and η-alumina with a specific surface area of 150 to 350 m ² /g is used. Further, as the silica, one having a specific surface area of 200 to 6600 m ² /g is used. Further, as for the silica-alumina, although the ratio of silica and alumina is not specified, commercially available products with an alumina content of about 13 and 28% by weight are easily available and are preferably used. The specific surface area is approximately
It is 200 to 600 m ² /g. The above flow aids are porous. Generally, the particle density is 0.6~1.6g/cm ³ and the average particle size is 55~65μ.
m, and those having a particle size distribution of 0 to 149 μm are preferably used. There are no particular limitations on the method of basifying the alumina, silica, or silica-alumina (hereinafter also simply referred to as fluidization aid) shown above. In general, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkaline earth metal hydroxides such as barium hydroxide and calcium hydroxide; alkalis such as sodium oxide, potassium oxide, and lithium oxide. Metal oxides; alkaline earth metals such as calcium oxide; further sodium carbonate,
Alkali metal carbonates such as potassium carbonate, particularly preferably alkali metal hydroxides, are used as basifying agents. These basifying agents are generally preferably used in aqueous solution. The basification method is not particularly limited, and a method of immersing the fluidization aid in an aqueous solution of a basification agent is preferred because it is simple. The degree of basification of the flow aid is preferably set to the acid strength function H _p = 6.8 or more, preferably 12 or more, and can be controlled by changing the type or concentration of the basification agent or the number of immersions. It is carried out with The flow aid thus made basic has its acid sites neutralized, and the carrier is further impregnated with the basifying agent. The amount of impregnation is generally 2% by weight or more, preferably 9% by weight or more in terms of hydroxide. In the present invention, "basic" means that the acid strength function H _p of the hook exhibits a basic color when the indicator is neutral red, and is 6.8 or more. (See pages 246-248, edited by the Catalysis Society, published in 1972, published by Makishoten). If the above-mentioned basicized flow aid is fired at a higher temperature, the basicity will decrease slightly, but a strong bond can be formed. However, in basic carriers obtained using alkaline earth metal hydroxides, oxides, carbonates, etc. as basifying agents, new acid sites are generated by high-temperature calcination, so high-temperature calcination is not recommended in this case. Undesirable. In the present invention, the amount of the basified fluidized aid added in the fluidized bed is preferably in the range of 10 to 80% by weight based on the particles in the entire fluidized bed. If the amount of the fluidity aid added is less than 10% by weight, the fluidity effect will not be sufficient. As the amount of the fluidization aid added increases, the fluidity becomes better, but the reaction rate decreases because the proportion of the catalyst components in the total decreases. Generally, the proportion of the catalyst component in the particles of the entire fluidized bed is 8 to 30% by weight, so it is preferable to set the upper limit of the amount of fluidizing aid added within this range. When the proportion of the catalyst component in the particles of the entire fluidized bed is 8% by weight, the amount of fluidization aid added is up to 30% of cupric chloride to γ-alumina.
When using a catalyst supported by weight%, the amount is 73% by weight. Furthermore, when silica-alumina is used as the catalyst carrier, the amount of cupric chloride supported can be further increased, so the amount of fluidization aid added can be further increased. Taking these things into consideration, the upper limit of the amount of flow additive added is generally 80% by weight. In the present invention, conventionally known reaction conditions can be used as they are for the reaction conditions in the fluidized bed. For example, by oxychlorination of ethylene, 1,
When producing 2-dichloroethane, the reaction temperature is generally 200 to 300℃ and the reaction pressure is normal pressure to 5Kg/ ^cm2.
G is adopted. The basicized fluidized auxiliary material of the present invention can cause side reactions in the oxyhalogenation reaction using a fluidized bed.
In particular, it has the characteristic of significantly suppressing combustion reactions. Therefore, the production of 1,2-dichloroethane by oxychlorination of ethylene, 1,2-
It is preferably used in the production of trichlorethylene and perchlorethylene by oxychlorination of dichloroethane, and the production of methylene chloride, carbon tetrachloride, and chloroform by oxychlorination of methane. The present invention will be described below with reference to Examples, but the present invention is not limited thereto. To measure the acid strength function H _p , put approximately 0.1 g of the sample into a test tube, add 3 to 5 ml of benzene, and then add a small amount of benzene solution containing 0.1% of various PKa indicators shown in Table 1. In addition, I observed the colors. Further, in the examples, the selectivity was determined using the following formula. Selectivity = Number of moles of ethylene converted into product / Number of moles of reacted ethylene × 100 (%)

【table】

[Table] Example ₁ γ-Alumina (specific surface area 203 m ² /
g) in a 13% cupric chloride aqueous solution for 3 hours,
It was then dried at 120°C to obtain a catalyst. The amount of cupric chloride supported as a catalyst component was 20% by weight. The same γ-alumina as above was immersed in a 6% sodium hydroxide aqueous solution for 3 hours and dried at 120°C, so that the amount of sodium hydroxide impregnated was 9% by weight, and the acid strength function H _p was +
A flow aid of 15.0 to +18.4 was obtained. 30ml of the above catalyst and fluidization aid mixed at a weight ratio of 2:1
used. At this time, the proportion of cupric chloride in the particles of the entire fluidized bed was 13.3% by weight. The reactor was made entirely of glass and had an inner diameter of 30 mm. A cyclone was attached to the upper part of the reactor, and a glass filter dispersion plate was attached to the lower part to circulate the catalyst particles. This reactor was placed in a temperature-controlled sand bath, and oxychlorination reaction of ethylene was carried out at 260°C and normal pressure. As raw materials, ethylene, hydrogen chloride, and oxygen were used in a molar ratio of 2:4:1, and nitrogen was used in a molar ratio of nitrogen:oxygen.
A total of 3.51 mol/hr was supplied so that the ratio was 79:21.
The fluidity during the reaction was good. The results of the reaction were as shown in Table 2.

【table】

[Table] Comparative Example 1 A case was conducted in which no flow additive was used. A catalyst in which 14.7% of cupric chloride was supported on the same γ-alumina as used in Example 1 was obtained by a dipping method. Oxychlorination of ethylene was carried out using only this catalyst under the same conditions as in Example 1, but the fluidity was poor. The results of the reaction were as shown in Table 3.

[Table] Comparative Example 2 The same γ-alumina used in Example 1 was immersed in a 10% cupric chloride aqueous solution and dried at 120°C, which was used as a catalyst. The amount of cupric chloride supported on γ-alumina was 15% by weight. This catalyst and a fluidizing aid made of the same γ-alumina used in Example 1 were
Oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1 using a mixture at a weight ratio of 2:1. The fluidity was good during the reaction. The results of the reaction were as shown in Table 4.

[Table] Examples 2 to 4 The same γ-alumina used in Example 1 was immersed in an aqueous sodium hydroxide solution to obtain γ-alumina impregnated with 9% by weight of sodium hydroxide. The acid strength function H _p of this was +15.0 to +18.4. Three sets of this were prepared and further immersed in 13%, 17% and 20% cupric chloride aqueous solutions and dried at 120°C, so that the amount of cupric chloride supported was 20%, 25% and 20% by weight, respectively.
A 30% by weight catalyst was obtained. These catalysts were designated as A catalyst, B catalyst and C catalyst, and were mixed with the same fluidizing aid as used in Example 1 at a ratio of 2:1.
The oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1. In all cases, the fluidity was good during the reaction. Moreover, the reaction results were as shown in Table 5.

[Table] Examples 5 to 6 The same γ-alumina used in Example 1 was immersed in a sodium hydroxide solution to obtain γ-alumina impregnated with 9% by weight of sodium hydroxide (acid strength function H
_p was +15.0 to +18.4). Two sets of these were prepared and further immersed in 10% and 18% cupric chloride aqueous solutions and dried at 120°C to obtain catalysts with cupric chloride supported amounts of 16% and 27% by weight, respectively. They were designated as catalyst D and catalyst E, respectively. Using the same fluidized additives as used in Example 1, the weight ratio of D catalyst and fluidized additive was 5:1, and the weight ratio of E catalyst and fluidized additive was 1:1.
A mixture of each of Step 1 was used. Although the addition ratio of the fluidizing aid is different between the two, the ratio of cupric chloride to the particles of the entire fluidized bed is approximately the same at 13% by weight. Oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1. In both cases, the fluidity during the reaction was good. The results of the reaction were as shown in Table 6.

[Table] Example 7 The same γ-alumina used in Example 1 was
Immersed in 1.4% sodium hydroxide aqueous solution at 120℃
It was dried. Sodium hydroxide impregnation amount is 2% by weight
Thus, a carrier having an acid strength function H _p of +6.8 to +12.2 was obtained. A portion of this carrier was used as a flow aid. In addition, another part of the carrier was immersed in a 13% cupric chloride aqueous solution and dried at 120°C, so that the supported amount of cupric chloride was 20%.
wt% catalyst was prepared. An oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1 using a mixture of this catalyst and the above-mentioned fluidization aid at a weight ratio of 2:1, but the fluidity was good. Ta. The results of the reaction were as shown in Table 7.

[Table] Example 8 The same γ-alumina used in Example 1 was immersed in a 6% lithium hydroxide aqueous solution for 3 hours and dried at 120°C. A carrier was obtained in which the amount of lithium hydroxide impregnated was 9% by weight and the acid strength function H _p was +6.8 to +15.0. A part of this carrier was used as a fluidization aid. In addition, another part of the carrier was immersed in a 13% cupric chloride aqueous solution and dried at 120°C to obtain a catalyst. The amount of cupric chloride supported was 20% by weight. When the oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1 using a mixture of this catalyst and the above-mentioned fluidization aid at a weight ratio of 2:1, the fluidity state was good. . The reaction results were as shown in Table 8.

[Table] Example 9 Silica/alumina with an alumina content of 28.6% by weight (specific surface area 510 m ² /g, average particle size 61 μm, acid strength function H _p <-8.2) was immersed in a 6% sodium hydroxide aqueous solution for 3 hours. , dried at 120°C. A carrier was obtained in which the amount of sodium hydroxide impregnated was 9% by weight and the acid strength function H _p was +6.8 to +15.0. A part of this carrier was used as a fluidization aid. In addition, another part of the carrier was immersed in a 13% cupric chloride aqueous solution and dried at 120°C to obtain a catalyst. The amount of cupric chloride supported was 20% by weight.
Oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1 using a mixture of the catalyst thus prepared and the fluidization aid described above at a weight ratio of 2:1. The fluidity was good during the reaction. The results of the reaction were as shown in Table 9.

【table】

[Table] Example 10 The same γ-alumina used in Example 1 was immersed in a 6% aqueous sodium hydroxide solution and dried at 120°C. The amount of sodium hydroxide impregnated was 9% by weight, and the acid strength function H _p was +15.0 to +18.4. this
It was immersed in a 13% cupric chloride aqueous solution and dried at 120°C to obtain a catalyst with a supported amount of cupric chloride of 20% by weight. Silica gel with an average particle size of 60 μm (acid strength function H
( _p : -3.0 to +4.8, specific surface area: 320 m ² /g) was immersed in a 1.4% aqueous sodium hydroxide solution and dried at 120°C to obtain a flow aid. The amount of sodium hydroxide impregnated was 2% by weight, and the acid strength function H _p was +6.8 to +12.2. Oxychlorination reaction of ethylene was carried out under the same conditions as in Example 1 using a mixture of the catalyst and fluidization aid at a weight ratio of 2:1.
The fluidity was good during the reaction. The results of the reaction were as shown in Table 10.

[Table] Example 11 The same γ-alumina used in Example 1 was
% sodium hydroxide aqueous solution and dried at 120°C. A carrier was obtained in which the amount of sodium hydroxide impregnated was 9% by weight and the acid strength function H _p was +15.0 to +18.4. A part of this carrier was used as a fluidization aid. Another part of the carrier was immersed in an aqueous solution containing 8% cupric chloride and 1% potassium chloride for 3 hours and dried at 120°C.
Catalysts with supported amounts of cupric chloride and potassium chloride of 12% by weight and 1.5% by weight were obtained. Oxychlorination reaction of 1,2-dichloroethane was carried out at 420° C. using a mixture of this catalyst and the fluidization aid at a weight ratio of 2:1. The glass reactor used in Example 1 was used as the reaction apparatus. The amount of catalyst used was 30 ml, and the raw materials were 1,2-dichloroethane, which had been gasified by heating in advance, hydrogen chloride, and oxygen in a molar ratio of 1:
Nitrogen:oxygen was added at a molar ratio of 1:11 and a molar ratio of nitrogen:oxygen of 79:21, and a total of 2.79 mol/hr was supplied. The fluidity was good during the reaction. The reaction results were as shown in Table 11.

[Table] Example 3 8% γ-alumina similar to that used in Example 1
The sample was immersed in an aqueous solution containing 1% cupric chloride and 1% potassium chloride for 3 hours, and dried at 120°C.
Catalysts were obtained in which the supported amounts of cupric chloride and potassium chloride were 12% by weight and 1.5% by weight, respectively. Using a mixture of this catalyst and a flow aid made of γ-alumina similar to that used in Example 1 at a weight ratio of 2:1, oxychloride of 1,2-dichloroethane was prepared under the same conditions as in Example 11. A lineation reaction was performed. The fluidity was good during the reaction. The reaction results were as shown in Table 12.

【table】

Claims (1)

[Scope of Claims] 1. In a method of oxyhalogenating hydrocarbons or halogenated hydrocarbons in a fluidized bed in the presence of a catalyst, the fluidization aid is selected from basicized alumina, silica, and silica-alumina. An oxyhalogenation method characterized by using at least one type of particles. 2. The method according to claim 1, wherein the oxyhalogenation method of hydrocarbons is an oxychlorination reaction of ethylene. 3. The method according to claim 1, wherein the catalyst is an acidic carrier which has been basified and has an oxyhalogenated catalyst component supported thereon. 4. The method according to claim 3, wherein the acidic carrier is silica, alumina, or silica-alumina. 5. The method according to claim 1 or 3, wherein the basification treatment is performed using an alkali metal hydroxide. 6 Acid strength function H of basicity of flow aid
The method according to claim 1, wherein _p is 12 or more. 7 The basicity of the acidic carrier is determined by Hammett's acid strength function H.
The method according to claim 3, wherein _p is 12 or more. 8. The method according to claim 1, wherein the amount of the basicized fluidization aid added in the fluidized bed is 10 to 80% by weight based on the particles in the entire fluidized bed.