JPH09173837A - Catalyst for fluid catalytic reaction for synthesizing hydrocarbon having 2 or more carbon atoms from methane and method for synthesizing hydrocarbon by the catalyst - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: A catalyst for a fluid catalytic reaction for synthesizing a hydrocarbon having 2 or more carbon atoms from methane, which has a high methane conversion rate in terms of activity and is in a stable fluid state during use. To be able to maintain. SOLUTION: A slurry containing a component A made of an alkaline earth metal oxide, a component B made of an alkali metal oxide, and a component C made of an inorganic oxide as raw materials is spray-dried and then fired at a temperature of 600 ° C. or higher. Therefore, A, B,
The powder is a composite oxide of C component.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to fluidized contact for reacting methane or a natural gas containing methane with oxygen or an oxygen-containing gas to synthesize a hydrocarbon having 2 or more carbon atoms mainly containing ethane and ethylene. The present invention relates to a reaction catalyst and a method for synthesizing a hydrocarbon having 2 or more carbon atoms using the catalyst.

[0002]

2. Description of the Related Art Methane is an abundant resource that exists abundantly in the world as a main component of natural gas, but due to its low reactivity, most of it is consumed as a fuel and used as a raw material for the chemical industry. The law is limited. However,
In 1982, when Keller and Virgin partially oxidized methane using a redox metal oxide as a catalyst, ethane,
The production of ethylene is reported in Journal of Catalysis, Vol. 73, pages 9-19. Since then, many catalysts useful for this reaction called oxidative coupling reaction of methane have been reported. When these are classified, most of them use an alkali metal and an alkaline earth metal and a rare earth metal such as a lanthanoid, or a catalyst in which these are combined.

In particular, many catalysts containing an alkaline earth metal as a main component have been reported. For example, JP-A-62-267
Japanese Laid-Open Patent Publication No. 243425 discloses a catalyst formed by impregnating an alkaline earth metal oxide such as calcium oxide with an alkali metal, and JP-A-2-225425 discloses a composite oxide catalyst containing an alkali metal oxide in magnesium oxide. Kaihei 4-2
Japanese Patent No. 95434 discloses a method for producing ethane and ethylene by using an alkaline earth metal oxide, lithium oxide, a lanthanoid oxide catalyst and the like.

[0004]

All of these catalysts are used in a fixed bed. However, when a reaction with large heat generation such as an oxidative coupling reaction of methane is carried out in a fixed bed, there is a big drawback that the catalyst component scatters due to a local temperature rise of the catalyst layer. Also, regarding the concentration of the reaction gas, it is necessary to carry out the reaction at a low oxygen concentration.
The production yield of the above hydrocarbons also decreases.

As a method for solving these drawbacks, a fluidized bed reaction is preferable because the temperature of the catalyst bed is uniformly controlled and the reaction can be carried out at a high oxygen concentration. However, there is no suitable catalyst for fluid catalytic reaction for oxidative coupling reaction of methane. The catalyst for fluid catalytic reaction used in a fluidized bed has a bulk specific gravity and an average particle diameter suitable for maintaining a stable fluidized state, in addition to catalytic performance such as activity and selectivity, and a shape close to a sphere. Therefore, excellent particle strength is required.

The object of the present invention is to obtain a methane having a bulk specific gravity, a particle size, a specific surface area and a spherical shape suitable for a fluidized catalyst in a fluidized bed reaction, and having a high methane conversion rate and selectivity on the active surface. A catalyst for fluid catalytic reaction for synthesizing a hydrocarbon having 2 or more carbon atoms, and a method for synthesizing a hydrocarbon by the catalyst.

[0007]

To achieve the above object, the catalyst for fluid catalytic reaction for synthesizing a hydrocarbon having 2 or more carbon atoms from methane according to the present invention is composed of an alkaline earth metal oxide A. Component B, consisting of an alkali metal oxide
Ingredients and binders as C components, A component content is 50-94 wt% B component content is 1-15 wt% C component content is in the range of 5-45 wt% Is.

The catalyst of the present invention is in the form of powder and is usually (a)-
It has the physical properties shown in (e). (a) Bulk specific gravity (g / ml) 0.4 to 1.2; measured using a graduated cylinder. (b) Specific surface area (m ² / g) 0 to 20; measured by BET method. (c) Pore volume (ml / g) 0.0 to 0.2; measured by N ₂ adsorption method. (d) Abrasion resistance (wt% / hr) 0.0 to 1.3; ACC method (e) Average particle diameter (μm) 30 to 200, preferably 30 to 150; Average particle diameter measured by a sieve.

The present invention comprises three components, A, B and C, and the composition range thereof is as follows: A component content is 50 to 94 wt% B component content is 1 to 15 wt% C component content is 5 to It must be in the range of 45 wt% and the content of A component is 50%
When it is less than the above range, the activity and selectivity of the catalyst are deteriorated, and when the content of the A component exceeds 94%, the catalyst cannot have the property of being usable as a fluidized catalyst.

The component B, together with the component C, is present in a highly dispersed state between the grains of the component A and in the pores, so that it has a binder action and an activity improving action. If the content of the component B is less than 1%, its effect is not exerted, and if it exceeds 15%, a melt is present on the surface of the particles to cause partial uneven distribution, and the particles cause caking, which is not preferable. When the B component is in the range of 1 to 15%, the B component exists in a highly dispersed state,
The desired effect can be sufficiently exerted with respect to the activity performance.

If the content of the C component is less than 5%, the fluidity and the particle strength will be poor, and if it exceeds 45%, the active component will be small, so that the desired activity performance cannot be obtained. When the C component is used in the range of 5% to 45% within the range of the A component and the B component, fluidity,
It has excellent particle strength and exhibits sufficient activity.

Further, it is essential that the catalyst of the present invention has the above-mentioned physical properties (a) to (e). (a) If the bulk specific gravity is less than 0.4, gas blow-through and catalyst scattering will exceed 1.2. If the bulk specific gravity exceeds 1.2, the catalyst layer will not expand because the catalyst is too heavy, and the fluidity of the catalyst will deteriorate. (b) If the specific surface area exceeds 20, it is not preferable because an excessive reaction occurs and the selectivity decreases. (c) When the pore volume exceeds 0.2, the contact time becomes long and excessive reaction occurs, which is not preferable. (d) If the abrasion resistance exceeds 1.3, the scattering and mixing of the catalyst on the downstream side (refining system) becomes a problem. Further, the load on the cyclone is increased and the catalyst is atomized, which is not preferable. (e) If the average particle diameter is out of the range, the fluidity of the fluid catalyst is deteriorated regardless of whether the average particle diameter is large or small.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst of the present invention is obtained by spray-drying a slurry obtained by mixing precursors of A component, B component and C component, and has an average particle size of 30 to 200 μm, preferably 3 μm.
It can be prepared by making spherical particles of 0 to 150 μm and calcining at a temperature of 600 ° C. or higher, preferably 800 to 1300 ° C.

In the preparation of the catalyst of the present invention, as component A, CaO, MgO, CaO, MgO, etc. obtained by calcining an organic salt or inorganic salt of Ca, Mg or a hydroxide can be used. Particularly, CaO obtained by firing shellfish or shells disclosed in JP-A-5-286871 is most preferable. It is considered that the shells that are particularly preferable as the component A have a fine pore structure formed by firing and contribute to the development of high performance. It is considered that this pore structure is formed by firing due to the complex involvement of conchiolin in the shell, the shell layer, the prismatic layer, and the nacreous layer, and a myriad of fine tubules.

As the raw material of the component B, reagents such as Li, Na, K, Rb and Cs hydroxides, nitrates, carbonates and sulfates can be used.

As the precursor of the C component, there are at least one kind of silica such as silicic acid solution and colloidal silica, and inorganic oxides such as silica-alumina colloid and alumina colloid. Alternatively, water glass containing components B and C, potash water glass, lithium silicate, or the like can be used.

In the present invention in which the three components are combined, the particle interface of the A component and / or the eluted A component and B component and C component form a complex oxide, and a catalyst having excellent strength can be obtained. Further, since it is also excellent in thermal stability, it is most preferable for a high temperature reaction such as an oxidative coupling reaction.
These ingredients are ineffective alone or in two components,
The inclusion of three components is an essential condition.

When the above-mentioned catalyst obtained by the present invention is used for the reaction in the presence of methane and oxygen under the following conditions, ethane and ethylene can be mainly produced. Further, the catalyst of the present invention can be used for producing any hydrocarbon other than the case of producing ethane and ethylene, as long as it has 2 or more carbon atoms such as propane, propylene, butane, butene, pentane and pentene. Can also be applied. [Reaction conditions] Methane / oxygen molar ratio = 1 to 100, preferably 2 to 5
0, more preferably 3 to 10 mixed gas space velocity (GHSV) = 500 to 100,0
00h ^-1 , preferably 2,000 to 50,000h ^-1 , more preferably 3,000 to 20,000h ^-1 reaction temperature = 500 to 1000 ° C, preferably 600 to 9
00 ° C, more preferably 700 to 850 ° C Reaction pressure = atmospheric pressure to 30 atmospheric pressure, preferably atmospheric pressure to 5 atmospheric pressure

The present invention will be described in more detail below with reference to examples. The following examples give a specific explanation to the invention described in the claims, but the present invention is not limited to the specific details described in the examples.

[Example 1] Coarse crushed sea bream crushed product (average particle size 10 μm; light transmission type particle size distribution measurement device, capa 700 manufactured by Horiba Seisakusho) after firing at 900 ° C for 10 hours ) 500 g was put in a wet pulverizer filled with alumina beads, 2.5 kg of pure water was added, and pulverization treatment was performed at 300 rpm for 1 hour. The concentration of CaO slurry is 15.9 wt% and the particle size of CaO is 1.4.
μm. 2.4 kg of the above CaO crushed slurry was placed in a 10 liter steam jacketed tank, and 215 g of a silicic acid solution (SiO ₂ concentration 4.8 wt%) that had been Na-depleted using an ion exchange resin while stirring well and Catalyst Kasei Kogyo Co., Ltd. 26 g of silica sol (SiO ₂ concentration 40.0 wt%) having a particle size of 80 nm was added. Furthermore, Kanto Chemical's first-class lithium nitrate (Li ₂ O concentration 35.7
wt%) 58 g was dissolved in 700 g of pure water, and a lithium nitrate aqueous solution was added. After concentrating the slurry at 100 ° C., it was cooled and dispersed with a homogenizer to obtain a solid content concentration.
A (CaO + SiO ₂ + Li ₂ O) slurry consisting of 14.3 wt% was obtained.
Then, after performing spray drying, calcination was performed to obtain a catalyst A. Properties of catalyst A are shown in Tables 1 and 2. An X-ray diffraction diagram is shown in FIG. A complex oxide of CaO-Li ₂ O-SiO ₂ was observed.

[0021]

[Table 1]

[Table 2]

Comparative Example 1 10 kg of the crushed CaO slurry (CaO concentration 15.9 wt%) prepared in Example 1 was placed in a 20-liter steam-jacketed SUS tank, concentrated, and then stirred well and the silicic acid solution (SiO 2) was added. ₂ concentration 4.8wt%) 1.84kg and particle size 80nm silica sol (SiO ₂ concentration 40.0wt%) 0.22kg
Was added. After stirring well, perform dispersion treatment,
A (CaO + SiO ₂ ) slurry having a solid content concentration of 18.0 wt% was obtained. Then, after spray-drying, calcination was performed at a high temperature to obtain a catalyst B. Table 1 and Table 2 show the properties of the catalyst B. The wear resistance of the catalyst was 2.3 wt% / hr, and the wear amount was large and the strength as a fluid catalyst was insufficient.

Example 2 Deer special grade magnesium carbonate powder manufactured by Kanto Chemical Co., Inc. was calcined at 1000 ° C. for 2 hours, coarsely pulverized with a bee, and then coarsely pulverized with a wet pulverizer filled with alumina beads. 400 g of the crushed product and 2 kg of pure water were added and crushed at 300 rpm for 1 hour. The particle size of the MgO ground slurry was 1.2 μm. 2.4 kg of MgO crushed slurry (MgO concentration 16.0 wt%) 1
The mixture was placed in a tank with a steam jacket of 0 liter, and heated at 100 ° C. with good stirring to concentrate it. The slurry concentration after concentration was 23.0 wt%. Silicic acid liquid (Si
220 g of O ₂ concentration of 4.8 wt% and SI-80P silica sol (SiO ₂ concentration of 40.
0wt%) 26.4g was added. Furthermore, lithium nitrate (Li ₂ O concentration
An aqueous lithium nitrate solution prepared by dissolving 59 g of 35.7 wt%) in 700 g of pure water was added. Next, dispersion treatment is performed to obtain a solid content of 1
A (MgO + SiO ₂ + Li ₂ O) slurry consisting of 5.9 wt% was obtained. Then, after performing spray drying, calcination was performed to obtain a catalyst C. Table 1 and Table 2 show the properties of the catalyst C.

[Examples 3 to 5] CaO prepared in Example 1
Using the crushed slurry, the addition amount of silica sol and lithium nitrate was changed by the method according to Example 1 (CaO + SiO ₂ + Li ₂
O) A slurry was obtained. Spray drying and then calcination were performed to obtain catalysts D, E and F. Catalyst D in Tables 1 and 2
The properties of E and F are shown. The amount of SiO ₂ in the catalyst is 5.0 each
, 10.5, 21.2wt%, the amount of Li ₂ O in the catalyst is 1.0 each
, 5.2, 11.1 wt%.

Comparative Example 2 Using the CaO ground slurry prepared in Example 1, the addition amounts of silica sol and lithium nitrate were changed by the method according to Example 1 (CaO + SiO ₂ + Li ₂ O).
A slurry was obtained. Spray drying was carried out, followed by calcination to obtain catalyst G. The amount of SiO ₂ in the catalyst was 30.0 wt% and the amount of Li ₂ O in the catalyst was 16.0 wt%. Table 1 and Table 2 show the properties of the catalyst G. When the catalyst G was taken out from the container after firing, the particles fused and were completely solidified.

[Example 6] The CaO ground slurry prepared in Example 1 was used in the same manner as in Example 1 except that sodium hydroxide was used instead of lithium nitrate in the same manner as in Example 1 (CaO + SiO ₂ + Na ₂ O) slurry was obtained. After spray drying, calcination was performed to obtain a catalyst H. Table 1 and Table 2 show the properties of the catalyst H.

Example 7 2.05 kg of CaO ground slurry (Ca0 concentration 15.9 wt%) prepared in Example 1 was added to potassium water glass (SiO ₂ concentration 20.5 wt%, K ₂ O concentration) manufactured by Dokai Kagaku Co., Ltd. 9.0wt%)
122 g was added and diluted with 400 g of pure water to prepare a solid content concentration of 14.0 wt%. The pH of the slurry was 13.9 and the viscosity was 1760 cp. Then, after dispersing with a disperser, spray drying was performed, and then firing was performed to obtain a catalyst I. Table 1 and Table 2 show the properties of the catalyst I.

Example 8 2.05 kg of the CaO ground slurry (CaO concentration 15.9 wt%) prepared in Example 1 was added to Honjo Chemical Co., Ltd. lithium silicate (SiO ₂ concentration 19.7 wt%, Li
₂ O concentration 2.42 wt%) 163 g was added and diluted with pure water 360 g to prepare a solid content concentration of 14.0 wt%. The pH of the slurry was 13.4 and the viscosity was 1150 cp. Then, after dispersing with a disperser, spray drying was performed, and then firing was performed to obtain a catalyst J. Table 1 and Table 2 show the properties of the catalyst J.

Example 9 The CaO ground slurry prepared in Example 1 was used in the same manner as in Example 1 except that potassium hydroxide was used instead of lithium nitrate in the same manner as in Example 1 (CaO + SiO ₂ + A K ₂ O) slurry was obtained. After spray drying, calcination was performed to obtain catalyst K. Table 1 and Table 2 show the properties of the catalyst K.

[Example 10] With respect to the catalyst H obtained in Example 6 and the catalyst K obtained in Example 9, a fluidized bed reactor (inner diameter 22 mm) equipped with a sheath tube having an outer diameter of 6 mm inside the reaction tube Table 3 shows the reaction results when a methane oxidative coupling reaction was carried out under the following conditions. The reaction temperature was measured by a thermocouple inserted in the catalyst layer. The analysis of the product was carried out using an online gas chromatograph. Note that (C ₂ + selectivity) in the table has 2 to 2 carbon atoms.
5 shows the total selectivity of 5 hydrocarbons.

[0031]

[Table 3]

[Reaction conditions] Methane / oxygen molar ratio = 2 to 10 Raw material gas supply rate = 20 to 70 NL / hr Reaction temperature = 750 to 850 ° C. Reaction pressure = Atmospheric pressure Catalyst amount = 20 cc

[0033]

EFFECTS OF THE INVENTION According to the present invention, the component A composed of an alkaline earth metal oxide, the component B composed of an alkali metal oxide, and the component C composed of an inorganic oxide form a composite oxide, so that a strong bond is formed. A catalyst for fluid catalytic reaction having excellent physical properties can be prepared by force.

[Brief description of the drawings]

FIG. 1 is a diagram showing an X-ray diffraction pattern of catalyst A of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C10L 3/06 6958-4H C10L 3/00 A (72) Inventor Susumu Fujii Kitaminato-cho, Wakamatsu-ku, Kitakyushu City 13-2 Catalytic Chemical Industry Co., Ltd., Catalytic Research Laboratory (72) Inventor Koichi Ohama 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu City Catalytic Chemical Industry Co., Ltd.

Claims (4)

[Claims] 1. A component comprising an alkaline earth metal oxide, a B component comprising an alkali metal oxide and a binder as C components, the content of the A component is 50 to 94 wt%, and the content of the B component is 1. A catalyst for fluid catalytic reaction for synthesizing a hydrocarbon having 2 or more carbon atoms from methane, characterized in that the content of C component is in the range of 5 to 45 wt%. 2. The powdery catalyst for fluid catalytic reaction according to claim 1, which has the following physical properties (a) to (e). (a) Bulk specific gravity (g / ml) 0.4 to 1.2 (measured by graduated cylinder) (b) Specific surface area (m ² / g) 0 to 20 (measured by BET method) (c) Pore volume (ml / g) ) 0.0 to 0.2 (measured by N ₂ adsorption method) (d) abrasion resistance (wt% / hr) 0.0 to 1.3 (measured by ACC method) (e) average particle size (μm) 30 to 200 (measured by sieve) 3. The component A is at least one alkaline earth metal oxide selected from Mg and Ca, and the component B is Li, Na, K, Rb, C.
The fluidized contact according to claim 1, 2 or 3, wherein at least one alkali metal oxide selected from s and C component comprises at least one binder selected from silica, silica-alumina and alumina. Reaction catalyst. 4. A method for synthesizing a hydrocarbon having 2 or more carbon atoms by contacting methane with a catalyst according to claim 1, 2 or 3 in a fluidized bed in the presence of oxygen to carry out an oxidative coupling reaction.