JPS6287246A - Production of silver catalyst for producing ethylene oxide - Google Patents

Abstract

PURPOSE:To obtain the titled highly selective catalyst with reduced pressure drop by using a porous inorg. refractory carrier of an interlox saddle or a Berl saddle type for the silver catalyst for producing ethylene oxide. CONSTITUTION:When ethylene oxide is produced by the gaseous phase catalytic oxidation of ethylene with molecular oxygen in the presence of a halogenation inhibitor, the porous inorg. refractory carrier of an interlox saddle or a Berl saddle shape is used. The carrier is impregnated with a soln. of a silver compd. incorporated with a reducing compd. and the material is heated and reduced to disperse and deposit metallic silver on the outer surface of the carrier and on the inner wall surface of the pore. Then the product is washed with water and/or a lower alcohol, dried and further impregnated with a soln. contg. an alkali metal and/or its compd. The liq. component is evaporated to dry the product. The highly selective catalyst with reduced pressure drop is thus obtained.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to a method for producing a silver catalyst for producing ethylene oxide, which is used in producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor. It is. [Conventional technology] The silver catalyst used industrially to produce ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor has a high selectivity due to its performance. properties, high activity, durability of catalyst life, and low pressure loss in the catalyst layer are required. In response to these demands, various studies have been made to date to improve the performance, and much effort has been made to improve carriers, reaction accelerators, silver compounds, etc. Various methods have been proposed for supporting silver. For example, Japanese Patent Publication No. 46-19606, Japanese Patent Publication No. 55-22146, Japanese Patent Publication No. 59-29291, U.S. Patent No. 4305844,
Attempts have been made to improve the method of supporting silver in various publications such as US Pat. No. 4,400,308. As for reaction accelerators, alkali metals and thallium are mainly considered effective, and various proposals have been made regarding the type and addition of the elements and methods of addition. For example, JP-A-49-30286, JP-A-50-50307, JP-A-50-74589, JP-A-50-95213,
JP-A-50-160187, JP-A-52-11729
No. 3, Special Publication No. 59-29293, Japanese Patent Publication No. 127-1983
No. 144, JP-A-56-5471, JP-A-57-10
These include the specifications of each publication of No. 7240. Many reports regarding rough carriers have been proposed. For example, Special Publication No. 42-1412, Special Publication No. 43-13
No. 137, Special Publication No. 45-21373, Special Publication No. 45-2
No. 2419, Japanese Patent Publication No. 11217 of 1972, Japanese Patent Publication No. 1983-
No. 89843, US Pat. No. 2,766,261, US Pat. No. 3,172,893, US Pat. No. 3,664,970, and US Pat. It is.

[Problems to be solved by the invention]

However, none of these methods discloses the improvement of selectivity and catalyst layer pressure drop by the shape of the carrier, and only pellets, spheres, and Raschig rings, which are the shapes that have been mostly adopted on an industrial scale, have been disclosed. It's just that it's being done. Furthermore, in Japanese Patent Publication No. 59-29293, a porous inorganic refractory carrier is impregnated with a silver compound solution containing a reducing compound, and heat reduction treatment is performed to coat the outer surface of the carrier and the inner wall surface of the pores with metallic silver. water and/or
Alternatively, a method is disclosed in which the material is washed with a lower alcohol, dried, and further impregnated with a solution containing an alkali metal and/or an alkali metal compound, and the liquid component is evaporated to dryness. This method has the highest selectivity, highest activity,
This method is one of the methods for producing an industrial silver catalyst having a catalytic performance that has the best durability and long catalyst life, but it is still not fully satisfactory in terms of selectivity. There are still many unknown points regarding silver catalyst supports for ethylene oxide production, and there are many problems that need to be improved. For example, the components constituting the carrier, the specific surface area of the carrier, pore diameter, pore distribution, pore volume, porosity, particle size, physical properties such as shape,
Other improvements include optimization of the chemical properties of carrier materials such as α-alumina, silicon carbide, silica, and zirconia. Therefore, an object of the present invention is to provide a method for producing a silver catalyst for producing ethylene oxide, which is used in producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor. It is in. Another object of the present invention is to produce a silver catalyst with low pressure loss in the catalyst layer, which produces ethylene oxide with high selectivity by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor. The purpose is to provide a method. The present inventors selected a carrier with a suitable shape for use in a silver catalyst for producing ethylene oxide, and as a result of conducting research on a new silver catalyst for producing ethylene oxide that is suitable for that carrier, the present inventors achieved a highly selective carrier than ever before. It is possible to obtain a method for producing a catalyst that is highly resistant and has low pressure loss in the catalyst layer.
They discovered this and completed the present invention. [Means for Solving the Problems] The present invention provides a porous thermal R used when producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular M-strands in the presence of a halogenation reaction inhibitor. In a method for producing a silver catalyst in which fine silver particles are dispersed and adhered to the outer surface and inner wall surface of pores of a refractory carrier, a reducing compound is added to a porous inorganic refractory carrier that determines the shape of an interlock saddle or a Berl saddle. After impregnation with a silver compound solution containing 13 and heat reduction treatment to disperse and support metallic silver on the outer surface of the body and the inner wall surface of the pores, it is washed with water and/or lower alcohol, and after drying, it is roughly coated with an alkali. Ethylene oxide is produced by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor, characterized in that it is impregnated with a solution containing a metal and/or an alkali metal compound and the liquid components are evaporated to dryness. Ethylene oxide used in manufacturing ￥J m
This invention relates to a method for producing a silver catalyst. Studies on suitable supports for use in silver catalysts for the production of ethylene oxide have shown that porous supports with the shape of interlocked saddles or Berl saddles are preferable to the sphere or Raschig ring shaped supports commonly used in the prior art on an industrial scale. An amorphous refractory carrier is impregnated with a silver compound solution containing a reducing compound, heated and reduced to disperse and support metallic silver on the outer surface of the carrier and the inner walls of the pores, and then washed with water and/or lower alcohol. After drying, the catalyst was further impregnated with a solution containing an alkali metal and/or an alkali metal compound, and the liquid components were evaporated to dryness. It was discovered that a catalyst with low pressure loss can be obtained. The catalyst used to produce ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor is a silver catalyst, and most of them are supported catalysts using a carrier. It goes without saying. It is also well known that the carrier used is a porous particulate refractory. However, even if it is simply called a porous granular refractory carrier, there are a wide variety of differences in the carrier's specific surface area, pore distribution, pore volume, particle size, etc.
Physical properties such as shape and material constituting the carrier, e.g. α
-The physical and chemical properties of alumina, silica, silicon carbide, zirconia, clay, etc. have a great influence on the performance of the catalyst. Therefore, it is a big problem for those skilled in the art how to select a carrier having properties. In particular, the shape of the support has a great relationship with catalyst performance, and during catalyst production, silver, alkali metals and/or
Alternatively, in the step of supporting an alkali metal compound, choosing a carrier shape that is uniform and easy to support will result in a catalyst with excellent selectivity. In addition, one way to obtain a catalyst with excellent selectivity is to select a carrier shape that prevents gas from stagnation within the particles of the reaction cocatalyst and makes it easy to remove reaction heat. It is advantageous to have a larger ratio between the apparent surface area and the apparent volume (excluded volume) of the carrier.The shape of most carriers used on an industrial scale so far has been spherical or Raschig ring; In order to increase the ratio, the particle size of the sphere can be made smaller.However, if the particle size is made too small, the pressure loss during the reaction will be very large, which is disadvantageous in terms of both equipment and utility. Although it is effective to reduce the thickness of the Raschig ring to increase this increase, it is disadvantageous because it reduces the crushing strength and the catalyst surface area per unit volume of the reaction tube. It cannot be said that the larger the ratio between the apparent surface area and the volume of the carrier (j), the better, and there will naturally be limitations. As a result of examining carriers of various shapes, the present inventors have decided to use an interlocked saddle or a Berl saddle. It has been found that a catalyst using a porous inorganic refractory carrier having a shape has high selectivity and low pressure loss in the catalyst layer. Porous inorganic refractory carriers having an interlock saddle and a Berl saddle shape have a high selectivity and a low pressure loss in the catalyst layer. compared,
When the particle size and wall thickness are the same, the filling specific gravity is small, which means that the catalyst surface area per unit volume of the reaction tube is small. It is surprising that a catalyst with excellent selectivity and low pressure loss in the catalyst layer was obtained despite the shape of the catalyst, which is considered to be disadvantageous for rJ. In catalysts using spheres or Raschig ring supports, even if the ratio of the apparent surface area to the particle volume is the same as that of catalysts using porous inorganic refractory supports with the shape of interlocked saddles or Berl saddles. However, catalysts using porous inorganic refractory carriers having the shape of interlocked saddles or Berl saddles do not have high selectivity or low pressure loss. In addition, a catalyst using a porous inorganic refractory carrier having the shape of an interlox saddle or Berl saddle and a catalyst using a ball or Raschig ring carrier with the same packing specific gravity is a porous inorganic refractory carrier having the shape of an interlox saddle or Berl saddle. The catalyst using this method does not result in any high selectivity and low pressure drop. The specific surface area of the porous inorganic refractory carrier having the shape of interlock noodle or Berl saddle of the present invention is 0.01 k/g to 10 rrl/Q, particularly 0.1 to 5 m
/Q range is valid. If it is less than 0゜01rrh/Q, the filling specific gravity of the porous inorganic refractory +p body having the shape of interlock saddle or Berl saddle is small, so the surface area per unit volume of the reaction tube becomes very small, which is disadvantageous in terms of activity. If it exceeds 10 m/C1, the pore diameter of the carrier becomes too small, and reaction gas and product gas tend to stagnate within the particles of the catalyst during reaction. Furthermore, the ratio of the apparent surface area to the apparent volume of the porous inorganic refractory carrier having the shape of an interlock saddle or a Berl saddle used in the present invention is 0.1 to 10 mm.
-1. If the ratio of the apparent surface area to the apparent volume is less than 0.1 mm-1, the wall thickness will increase and the selectivity will decrease. Further, if the ratio of the apparent surface area to the apparent volume exceeds 10 mm-1, the wall thickness becomes very thin and the strength necessary for an industrial catalyst cannot be maintained. The physical properties of the porous inorganic refractory carrier that determines the shape of the Interlox saddle are: apparent porosity of 20 to 80%, pressure pore volume of 0.06 to 1.0 cc/Q, and circumference length of A > 3.
~70mu+, especially 3.5~30II1m, inner circumference length C) 1.5~68mm, especially 1°8~28+++m,
Thickness W) 0. 1~4mm, especially 0°8~3ml
1. Outer diameter (D>0.5~20mm+, especially 3~15mm
, length E) 0.5 to 65 mm, particularly preferably 3 to 2 Q mm. The physical properties of the porous inorganic refractory carrier having the shape of a Berl saddle are an apparent porosity of 20 to 80% and a specific pore volume fJi.
o, 06~1.0CC/G, outer circumference △) 3~7
Qmm, especially 3.5-30mm, inner circumference length C)1.
5-68mm, especially 1.8-28mm, thickness W) 0
．． 1-4mm+, especially 0.8-3mm, outer diameter (D) 0
．． 5-20mm, especially 3-15mm, length E) 0.5
A range of ˜65 mm, especially 3-20 mm is preferred. In addition, as the 1r4 body material, α-alumina, silicon carbide, silica, zirconia, and clay are preferable, but
α-alumina is particularly suitable. Furthermore, the amount of carrier components other than the main carrier component is preferably the same as that contained in carriers commonly used in the art. Examples of the shape of the carrier used in the present invention are shown in the drawings. Figure-
1 to 3 show porous inorganic refractory carriers having an interlock saddle shape, and FIGS. 4 to 6 show porous inorganic refractory carriers having a Berle saddle shape. First, the catalyst according to the present invention is manufactured as follows. As the silver compound solution containing the reducing compound used in the present invention, all known solutions can be used, but effective solutions include a monoethylene glycol solution of silver nitrate containing a lower acid amide as a reducing component, and an alkanol solution. Solutions containing various silver compounds dissolved in alkanolamines or other amines containing amines as a reducing compound, silver nitrate aqueous solutions containing formalin as a reducing component, etc. can be used. Lower acid amides used as reducing compounds include:
Examples include formamide, acetamide, propionic acid amide, glycolic acid amide, dimethylformamide, and the like. As alkanolamines or amines,
Examples include 7-no-g-triethanolamines, 7-no-g-trily n-propanolamines, 7-no-g-trily isopropanolamines, n-butanolamines, and isobutanolamines. These reducing compounds have a reducing action at room temperature to 200° C. and reduce dissolved silver compounds to metallic silver. As the silver compound used as a raw material, any inorganic silver 33 or organic silver salt that reacts with the lower acid amide to form a famous salt can be used, but examples include silver nitrate,
Silver carbonate, silver sulfate, silver acetate, silver lactate, silver succinate, silver glycolate, etc. can be used. The silver support rate is 5 to 30% by weight, preferably 5 to 30% by weight based on the catalyst.
It is possible to precipitate 25 wt ω% in the form of fine particles on the inner and outer surfaces of the carrier. In addition, the solvent used is a lower aliphatic compound having 2 to 6 carbon atoms and having 1 to 3 alcoholic hydroxyl groups in one molecule, such as monoethylene glycol, dielene glycol, triethylene glycol, and trimethylene glycol. , monopropylene glycol, methyl cellosolve, ethyl cellosolve, and methyl carpitol are preferably used when lower acid amides are used. Furthermore, amines such as alkanolamines and water can also be suitably used as solvents. As the alkali metal or alkali metal compound, one or more selected from potassium, rubidium, and cesium metals or compounds can be used. Examples include various compounds such as nitrates, sulfates, hydroxides, oxides, and acetates. These are used in the form of aqueous solutions or lower alcohol solutions such as methanol, ethanol, and propatool. Alkali metals or alkali metal compounds are used for completion
0.0001 to 0.03 grams per 1.1 kilograms, especially o. ooos~0. It is preferably within the range of 0.02 grams. Next, a method for producing a silver-supported catalyst according to the present invention using a lower acid amide as a reducing compound will be specifically described. Silver nitrate is dissolved in between 1 and 20 parts by weight of a solvent, especially 1 to 10 parts by weight of a solvent, such as ethylene glycol. To this solution, add a reducing compound such as borumamide in an amount of 0.5 to 5 times the mole, especially 1 to 3 times the mole relative to the silver component, and after stirring well, add a predetermined amount of porous inorganic refractory having the shape of an interlox saddle or a Berl saddle. impregnated with a sexual carrier,
By heat treatment at 100 to 150° C. for 1 to 10 hours, silver becomes fine particles and is reduced and supported on the outer surface of the carrier and the inner wall surface of the pores. After the active silver is thus dispersed and adhered to the outer surface of the carrier and the inner wall surface of the pores, the carrier is washed with water, preferably with boiling water. This has the effect of removing organic substances such as formamide and ethylene glycol in the catalyst and cleaning the surface of the produced activated silver to further increase its activation. After washing, it is heated to 50-150'C and dried. Next, this catalyst is impregnated with an aqueous solution or a lower alcohol solution such as methanol or ethanol containing a reaction accelerator having a predetermined ω, and these solvents are removed by evaporation at 50 to 150°C. What should be noted in these processes is that the catalyst
Do not heat above ℃. In the method of producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular acid A1 using the silver catalyst of the present invention, the presence of a halogenation reaction inhibitor is essential. Examples of the halogenation reaction inhibitor include chlorinated products such as ethylene dichloride, 1=vinyl chloride, diphenyl chloride, monochlorobenzene, and dichlorobenzene, and halogenated products such as fluorinated products, brominated products, and iodized products. The concentration of the halogenation reaction inhibitor present when producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen is 0.1 to 10 Dl)m (volume), preferably 0.
．． It is essential that it be present at 5 to 5 ppm (volume a). A method for producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen using the silver catalyst of the present invention.
Furthermore, in the absence of a halogenation reaction inhibitor, the selectivity of ethylene oxide becomes low. The reaction conditions that can be employed in the method for producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor using the silver catalyst of the present invention are not known in the art. All conditions can be adopted. Industrial r? Typical conditions on scale, i.e. reaction temperature 150-300'C, preferably 180-300'C.
280°C, reaction pressure 2 to 40 k (1/cfG, preferably 10 to 30 kQ/ciG, intermediate speed 191,000 to 30
000Hr-1 (STP), preferably 3000-8
000Hr-1 (STP) is adopted. The composition of the raw material gas that passes through the catalyst is ethylene 0.5-40.
Capacity%, oxygen 3-10% by volume, carbon dioxide 5-30% by volume
, the balance being nitrogen, an inert gas such as argon, or water vapor, or a lower hydrocarbon such as methane or ethane. [Examples] Hereinafter, the present invention will be described in detail using Examples and Comparative Examples to make it more specific, but the present invention is not limited to these Examples unless it goes against the spirit thereof. Note that the rate of change and selectivity described in Examples and Comparative Examples were calculated using the following formula. Rate of change (%) = Selectivity (%) - Number of moles of ethylene converted to ethylene oxide
Formamide 636q was added to this solution and stirred well to prepare a silver impregnation solution. This impregnation solution has an apparent porosity of 60% and a BET specific surface area of 0.
．． 7 pores/g, pore volume 0.40CC/(], approximately 10 in advance
Heated to 0°C, outer diameter (D) 6.0 mm, thickness W) 2
．． 0mm, outer circumference length A) 13.3mm and inner circumference length C) 5.8mm, length E) 10.011111
, the ratio of apparent surface area to apparent volume is 1.7 m
After impregnating the α-alumina carrier (Figures 1 to 3) in the shape of an interlocking saddle of 9,000 m, the impregnated mixture was gradually heated to 130°C, stirred at that temperature for 2 hours, and then warmed to 160°C. The mixture was further stirred for 2 hours to disperse and adhere the reduced silver to the carrier.
After boiling and washing with 0 d of water, it was dried at 90 to 100°C. Next, 4.52 rJ of cesium carbonate was applied to the dried catalyst at 24,001 nf! Add a solution dissolved in ethyl alcohol to impregnate the resulting silver-supported catalyst at 80 to 100°C.
It was dried. This catalyst was packed into a heated double-tube stainless steel reactor with an inner diameter of 33 mm and a catalyst head length of 10,000 mm. A mixed gas consisting of methane, nitrogen, argon, and ethane and roughly 31) pm of ethylene dichloride was introduced, and the reaction was carried out for 30 days at a reaction pressure of 24 KG10+fG and a space velocity of 5500 Hr-'. 30
The results after 1 day are shown in Table 1. Example 2 Silver nitrate 1600a was dissolved in monoethylene glycol 1.71, and formamide 636q was added to this solution and stirred thoroughly to prepare a silver impregnation solution. This impregnation solution has an apparent porosity of 60% and a BET specific surface area of 0.
．． 7 conditions/g, pore volume 0.40cc10. Preheated to approximately 100°C, outer diameter (D) 6.0 mm. Thickness W) 2.0mm, outer circumference length A>15.4mm
a3 and inner circumference length C) 6.2n+m1 α-alumina carrier in the shape of Berlzadol with a ratio of apparent surface area to apparent volume of 1.7 mm”1 Figures 4 to 6) 9
000d, the impregnation mixture was gradually heated to 130°C, stirred at that temperature for 2 hours, heated to 160°C, and further stirred for 2 hours to allow the reduced silver to be dispersed and adhered to the carrier. The obtained silver-supported catalyst was washed several times with water at 900°C (7.
The dried catalyst was then impregnated with a solution of 4.31 g of cesium carbonate dissolved in 2300 td of ethyl alcohol, and the resulting silver-supported catalyst was dried at 80 to 100°C. This catalyst was packed into a heated double-tube stainless steel reactor with an inner diameter of 33 mm and a catalyst length of 10,000 mm. %, the balance being methane, nitrogen, argon, and ethane, and a mixed gas consisting of 3 ppm of ethylene dichloride was introduced, and the reaction was carried out for 30 days at a reaction pressure of 24 K(]/cmG and a space velocity of 5500 Hr-1. The results after 30 days are shown in Table 1. Example 3 Silver nitrate 1600 Ω was dissolved in monoethylene glycol 1.81, and 636 g of formamide was added to this solution and stirred well to prepare a silver impregnation solution. Apparent porosity 60%, BET specific surface area 0
．． 7TIt/g, pore volume 0.40CC/CI, preheated to about 100°C, outer diameter (D) 6.0mm, thickness W
) 2.0mm, outer circumference length A) 13.3mm and inner circumference length C) 5.8mm, length E) 10.0mm,
The ratio of apparent surface area to apparent volume is 4.7 mm
After impregnating the α-alumina carrier in the shape of an interlocked saddle (Figures 1 to 3) to 9,000 d, the impregnation mixture was gradually heated to 130°C and stirred at that temperature for 2 hours.
The temperature was raised to 0° C., and the mixture was further stirred for 2 hours to disperse and adhere the reduced silver to the carrier. The obtained silver-supported catalyst was boiled and washed several times with 9,000 liters of water and then dried at 90 to 100°C. Next, 9.61g of rubidium carbonate was added to this dried catalyst at 2400mf! The silver-supported catalyst obtained was dried at 80 to 100°C. This catalyst was packed into a heated double-tube stainless steel reactor with an inner diameter of 33 mm and a catalyst length of 10,000 mm. A mixed gas consisting of methane, nitrogen, argon, and ethane and roughly 3 ppm of ethylene dichloride was introduced, the reaction pressure was 24 Kg/iG, and the space velocity was 55.
The reaction was carried out at 00 Hr-' for 30 days. The results after 30 days are shown in Table-1. Example 4 1600 g of silver nitrate was dissolved in 1.81 g of monoethylene glycol, and 636 g of formamide was added to this solution and thoroughly stirred to prepare a silver impregnation solution. This impregnating solution was applied with a porosity of 60% and a BET specific surface area of 0.
．． 7'rd/g, pore volume 0.40cc/g, pre-approximately 1
Heated to 00°C, outer diameter (D)6. On+m, thick W
>2.0mm, outer circumference length A) 13.3mm and inner circumference length C) 5.8mm, length (E) 10.0mm,
Ratio of apparent surface area to apparent volume is 1.7 mm
Figures 1 to 3) After impregnation at 9000 m, the impregnated mixture was gradually warmed to 130°C and stirred at that temperature for 2 hours.
The temperature was raised to 60° C., and the mixture was further stirred for 2 hours to disperse and adhere the reduced silver to the carrier. The obtained silver-supported catalyst was heated several times at 9000°C.
After washing with boiling water in step d, it was dried at 90 to 100°C. Next, this dried catalyst was impregnated with a solution of 4.51y potassium acetate dissolved in 2400R1 ethyl alcohol, and the obtained silver-supported catalyst was dried at 80 to 100°C. This catalyst was packed into an externally heated double-tube stainless steel reactor with an inner diameter of 33 mm+ and a catalyst photoperiod of 10,000 mm.
In the packed bed, a mixed gas consisting of 20% by volume of ethylene, 7% by volume of oxygen, 7% by volume of carbon dioxide, the balance consisting of methane, nitrogen, argon, ethane, and roughly 31)l)m of ethylene dichloride. was introduced, and the reaction was carried out for 30 days at a reaction pressure of 24 Kg/cIiG and a space velocity of 5500 Hr-1. The results after 30 days are shown in Table-1. Comparative Example 1 Silver nitrate 1600 (+ monoethylene glycol 2.14
Formamide 636q was added to this solution and stirred well to prepare a silver impregnation solution. This impregnating solution had an apparent porosity of 60%, a BET specific surface area of 0.7 m/g, a pore volume of 0.40 cc/9, and was preheated to about 100°C.
The ratio of apparent surface area to apparent volume is 1.3 mm
”, outer diameter (D) 7.0 mm, inner diameter (B) 3.Q mm, length E) 7.0 mm, α-
After impregnating 9000 m of alumina carrier (Figures 7 to 9), the temperature of the impregnation mixture was gradually raised to 130°C, and after stirring at that temperature for 2 hours, the temperature was raised to 160°C, and further stirred for 2 hours to transfer reduced silver to the carrier. It was dispersed and adhered. The obtained silver-supported catalyst was boiled and washed several times with 9,000 ml of water and dried at 90 to 100"C. Then, a solution of 5.13 g of cesium carbonate dissolved in 2,700 ml of ethyl alcohol was added to the dried catalyst. The catalyst was impregnated and the resulting silver-supported catalyst was dried at 80 to 100°C. This catalyst was packed into a heated double-tube stainless steel reactor with an inner diameter of 33 mm and a photoperiod of 10,000 mm. A mixed gas consisting of 20% by volume of ethylene, 7% by volume of oxygen, 7% by volume of carbon dioxide, the balance being methane, nitrogen, argon, and ethane, and roughly 3 ppm of ethylene dichloride was introduced into the layer, and the reaction pressure was increased. 24Kg/cmG, space velocity 5
The reaction was carried out at 500 Hr-1 for 30 days. The results after 30 days are shown in Table-1. Comparative Example 2 1600g of 1M silver and 3.14j of monoethylene glycol
! Formamide 636Q was added to this solution and stirred thoroughly to prepare a silver impregnation solution. This impregnating solution had a porosity of 60%, a BET specific surface area of 0.7 g/l, a pore volume of 0.40 cc/9, and was preheated to about 100°C.
Ratio of apparent surface area to apparent volume is 1.7 mm
-1. After impregnating 9000 d of α-alumina carrier in the shape of a sphere with a diameter of 3°5 mm, the impregnated mixture was gradually brought to ambient temperature of 130°C, stirred at that temperature for 2 hours, and then heated to 160°C,
The mixture was further stirred for 2 hours to disperse and adhere the reduced silver to the carrier. The obtained silver-supported catalyst was washed several times with boiling water of 9,000 ml of water and then dried at 90 to 100°C. Next, this dried catalyst was impregnated with a solution prepared by dissolving 7.05 g of cesium carbonate in 3700 ml of ethyl alcohol, and the resulting silver-supported catalyst was dried at 80 to 100°C. This catalyst has an inner diameter of 33 nu++ and a catalyst photoperiod of 10,000 mm.
A double-tube stainless steel reactor with a heated exterior was filled with 20% by volume of ethylene, 7% by volume of oxygen, 7% by volume of carbon dioxide, and the balance was methane, nitrogen, argon, A mixed gas consisting of ethane and 3 ppm of ethylene dichloride was introduced, and the reaction was carried out for 30 days at a reaction pressure of 24 K (1/c #IG and a space velocity of 5500 Hr-1. The results after 30 sips are shown. Comparative Example 3 Silver nitrate 1600 () was mixed with monoethylene glycol 1.56
j! Formamide 636Q was added to this solution and stirred thoroughly to prepare a silver impregnation solution. This impregnation solution has an apparent porosity of 60% and a BET specific surface area of 0.
．． 7 butts/g, pore volume 0.40CC/! ], about 10 in advance
Heated to 0°C, the ratio of apparent surface area to apparent volume is 1.7 mm-', outer diameter (D) 7, Q mm, inner diameter (
B) α-Alumina carrier in the shape of a Raschig ring with a length of 4.2 mm and a length of E) 7°Q mm (Figures 10 to 12) 9
000Iai! After the impregnation, the impregnation mixture was gradually heated to 130°C.
After stirring at that temperature for 2 hours, the temperature was raised to 160° C. and further stirred for 2 hours to disperse and adhere the reduced silver to the carrier. The obtained silver-supported catalyst was boiled and washed several times with 9000 d of water and then dried at 90 to 100°C. Then, a solution prepared by dissolving 4.04 g of cesium 1diJ acid in 2130 d of ethyl alcohol was added to the dried catalyst to impregnate it, and the resulting silver-supported catalyst was dried at 80 to 100°C. This catalyst has an inner diameter of 33 mm and a catalyst FifS% of 10,000 m.
A double-tube stainless steel reactor with a heated exterior was filled with 20% ethylene, 7% oxygen by volume, and
A mixed gas consisting of 7% carbon dioxide gas, the balance being methane, nitrogen, argon, and ethane, and 3 ppm of ethylene dichloride was introduced, and the reaction was carried out for 30 days at a reaction pressure of 24 kg/crAG and a space velocity of 55008 r. Ta. The results after 30 days are shown in Table-1. Comparative example 4 Silver nitrate 1600 (+ monoethylene glycol 1.8j
! 636 g of formamide was added to this solution and stirred well to prepare a silver impregnation solution. This impregnation solution has an apparent porosity of 60% and a BET specific surface area of 0.
．． 7 butts/g, pore volume 0.40CC/(], approximately 10 in advance
Heated to 0°C, outer diameter (D) 6.0 mm, thickness W) 2
．． 0mm, outer circumference length A>13.3mm and inner circumference length C) 5.8n+m, length E) 10, OInm,
Ratio of apparent surface area to apparent volume is 1.7 mm
After impregnating the α-alumina carrier (Figs. 1 to 3) with 900 g of interlock saddle shape (7), the impregnation mixture was gradually heated to 130°C and stirred at that temperature for 2 hours.
The temperature was raised to 60° C., and the mixture was further stirred for 2 hours to disperse and adhere the reduced silver to the carrier. The obtained silver-supported catalyst was heated several times to 9000
After washing with boiling water in step d, it was dried at 90 to 100°C. Next, this dried catalyst was impregnated with a solution of 4.52 g of cesium carbonate dissolved in 2400 m of ethyl alcohol, and the silver-supported catalyst was dried at 80 to 100°C. The catalyst is packed in a heated double-tube stainless steel reactor with a diameter of 10,000 mm.
A mixed gas consisting of 20% by volume of ethisine, 7% by volume of oxygen, 7% by volume of carbon dioxide, and the balance being methane, nitrogen, argon, and ethane was introduced into the packed bed, and the reaction pressure was 24 kg/cmG.
The reaction was carried out for 30 days at a space velocity of 5500 Hr-1. The results after 30 days are shown in Table-1. Comparative Example 5 Silver nitrate 1600 (+ monoethylene glycol 1.71
Formamide 6360 was added to this solution and stirred well to prepare a silver impregnation solution. This impregnation solution has an apparent porosity of 60% and a BET specific surface v4.
0.7TIt/g, pore volume 0.40CC/g, preheated to about 100°C, outer diameter (D) 6.0mm, thickness W
) 2.0 mm, outer circumference length A > 15.4 mm, inner circumference length (C) 6.2 mm, and a ratio of apparent surface area to apparent volume of 1° 7 mm''. - After impregnating 9000 d of alumina support (Figures 4 to 6), the impregnated mixture was gradually heated to 130℃ and stirred at that temperature for 2 hoursvi The temperature was raised to 160℃ and stirred for another 2 hours to disperse reduced silver in the carrier. The resulting silver-supported catalyst was boiled and washed several times with 9,000 d of water, and
Dry at °C. Next, 4.31 g of this dried catalyst was
of cesium carbonate dissolved in 2,300 d of ethyl alcohol to impregnate the silver-supported catalyst.
It was dried at 100°C. Cono catalyst inner diameter 33I1m, catalyst length 10000mm
A double-tube stainless steel reactor with a heated exterior was filled with the following: ethylene 20 volume R%, R element 7 volume ω%, carbon dioxide gas 7 volume%, the balance being methane, nitrogen, argon, A mixed gas consisting of ethane was introduced, and the reaction pressure was 24KQ/ci.
G, the reaction was carried out for 30 days at a space velocity of 5500 Hr-1. The results after 30 days are shown in Table-1. Effect of the invention 1 The outer surface and inner wall surface of the pores of a porous inorganic refractory carrier used in the production of ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor. In a method for producing a silver catalyst by dispersing and adhering fine silver particles, a porous inorganic refractory carrier having the shape of an interlocked saddle or a Berle saddle of the present invention is impregnated with a silver compound solution containing a reducing compound,
After thermal reduction treatment to disperse and support metallic silver on the outer surface of the carrier and the inner wall surfaces of the pores, the carrier is washed with water and/or lower alcohol, dried, and further impregnated with an alkali metal and/or alkali metal compound-containing solution. A silver catalyst for producing ethylene oxide produced by evaporating and drying a liquid component is a catalyst with unprecedented high selectivity and low pressure loss in the catalyst layer, and is highly effective industrially.

[Brief explanation of drawings]

The drawing shows the shape of the carrier. Figure 1 is a perspective view of the Interlox saddle carrier. Figure 2 is a front view of the Interlox saddle carrier. Figure 3 is a side view of the Interlox saddle carrier. Figure 4 is a perspective view of the Berl saddle carrier. Figure 5 is a front view of the Berl saddle carrier. Berl saddle carrier side view Figure 7 is a perspective view of the Raschig ring carrier Figure 8 is a front view of the Raschig ring carrier Figure 9 is a side view of the Raschig ring carrier Figure 10 is a perspective view of the Raschig ring carrier Figure 11 is a front view of the Raschig ring carrier Figure 12 is the Schich ring Support side view Patent applicant: Nippon Shokubai Chemical Co., Ltd. Figure 1 Figure 4 Figure 7

Claims (1)

[Claims] 1. Outer surface and pores of a porous inorganic refractory carrier used in producing ethylene oxide by catalytic gas phase oxidation of ethylene and molecular oxygen in the presence of a halogenation reaction inhibitor In a method for producing a silver catalyst in which fine silver particles are dispersed and adhered to the inner wall surface, a porous inorganic refractory carrier having an interlocked saddle or Berl saddle shape is impregnated with a silver compound solution containing a reducing compound, and then heated. After carrying out a reduction treatment to disperse and support metallic silver on the outer surface of the carrier and the inner wall surface of the pores, it is washed with water and/or lower alcohol, and after drying, an alkali metal and/or
Alternatively, a method for producing a silver catalyst for producing ethylene oxide, comprising impregnating it with an alkali metal compound-containing solution and evaporating the liquid component to dryness. 2. The method for producing a catalyst according to claim 1, wherein the porous inorganic refractory carrier having an interlock saddle shape has a specific surface area of 0.01 to 10 m^2/g. 3. The method for producing a catalyst according to claim 1, wherein the porous inorganic refractory carrier having the shape of a Berle saddle has a specific surface area of 0.01 to 10 m^2/g. 4. Any one of claims 1 to 2, wherein the porous inorganic refractory carrier having the shape of an interlocked saddle has a ratio of apparent surface area to apparent volume of 0.1 to 10 mm^-^1. Method for producing the catalyst described. 5. The ratio of the apparent surface area to the apparent volume of the porous inorganic refractory carrier having the shape of a Berl saddle is 0.1.
Claim 1 or 3 which is ~10mm^-^1
2. Method for producing the catalyst described in Section 1. 6. The method for producing a catalyst according to claim 1, which has a specific surface area of 0.50 to 2 m^2/g. 7. The method for producing a catalyst according to claim 1, wherein the apparent porosity is in the range of 20 to 80%. 8. The catalyst according to claim 1, wherein the supported amount of at least one selected from the group consisting of alkali metals and alkali metal compounds is 0.0001 to 0.03 gram equivalent weight per kilogram of finished catalyst. Production method. 9. Claim 1 in which the alkali metal is cesium
2. Method for producing the catalyst described in Section 1.