KR100891001B1 - Preparation method of zsm-5/sapo-34 composite catalyst and the use thereof for the conversion of oxygenates to light olefins - Google Patents

Abstract

A method for manufacturing a complex catalyst for making light olefins from an oxygenated compound and a manufacturing method of the light olefins using the same complex catalyst are provided to manufacture a complex catalyst of ZSM-5/SAPO-34 by performing a hydrothermal synthesis and plastic process about the compound. A method for manufacturing a complex catalyst for making light olefins from an oxygenated compound comprises the following steps of: for manufacturing alumina-silica mixed solution of a ZSM-5 type; manufacturing a synthesis gel of the ZSM-5 type; manufacturing a slurry of the ZSM-5 type after washing filtering and hydrothermal composition of the synthesis gel; manufacturing the alumina-silica compound of a SAPO-34 type; manufacturing a combinatorial synthesis gel of a ZSM-5/SAPO-34 type; and manufacturing a complex catalyst of a ZSM-5/SAPO-34 type.

Description

Preparation Method of ZSM-5 / SAPO-3 4 Composite Catalyst and the Use Thereof for the Conversion of Oxygenates to Light Olefins

The present invention is a method for producing a ZSM-5 / SAPO-34 composite catalyst by mixing a crystalline ZSM-5 obtained by hydrothermal synthesis in the manufacturing process of SAPO-34, and performing a series of processes for hydrothermal synthesis and firing; Under the ZSM-5 / SAPO-34 complex catalyst obtained by the above method, a reaction for converting an oxygen compound into a light olefin is carried out, and the selectivity of the light olefins in the C ₂ to C ₄ range is 70 carbon mol% or more, It relates to a process for producing light olefins in which the selectivity [C ₃ / C ₂ ] ratio for propylene can be maintained in a range of 1.0 or more.

ZSM-5 and silicoaluminophosphate (SAPO) molecular sieves are widely used in various fields as adsorbents and catalysts. When used in the field of dual catalysts, it is used in processes such as fluidized bed catalytic cracking, hydrocracking, isomerization, multimerization, conversion of alcohols or ethers and alkylation of aromatic compounds. For example, ZSM-5 and SAPO-34 molecular sieves are known as good catalysts for the conversion of alcohols or ethers to olefin products, in particular ethylene and propylene.

These two catalysts have different characteristics. ZSM-5 has low hydrothermal stability but high catalyst life, so it is applied to fixed bed reactors, and has relatively low selectivity for light olefins compared to SAPO-34, and mainly propylene. Its high yield is used as a catalyst for propylene production. On the other hand, SAPO-34 is applied to a circulating fluidized bed reactor capable of continuous regeneration due to rapid deactivation due to carbon deposition, and requires high hydrothermal stability. In addition, although the selectivity for light olefins is high, the yield for ethylene is mainly high, and thus catalyst improvement is required to increase selectivity for propylene.

Meanwhile, a method of preparing the catalysts of ZSM-5 and SAPO-34 will be described in detail.

ZSM-5 is generally used as a sodium hydroxide (NaOH) in a raw mixture of silica precursors such as sodium silicate and silica sol and various aluminum salts such as aluminum nitrate salts or alumina precursors such as pseudoboehmite and alumina sol. ) And tetrapropylammonium bromide (TPABr) are added and prepared through hydrothermal synthesis at about 170 ° C.

The method for preparing an olefin using ZSM-5 was first developed in Mobil (US Pat. Nos. 3,979,472, 4,025,575), and various patents and literature related to catalysts and reactors have been proposed. In particular, the company applied for a patent (US Pat. No. 6,048,816) that applied steam-treated ZSM-5 to the same reaction to increase the hydrothermal stability of the catalyst, and the Chinese Dalian Institute of Chemical Physics applied ZSM- modified to phosphorous. 5 has been proposed as a catalyst for the conversion of olefins from methanol (US Pat. No. 5,367,100).

In addition, SAPO is an organic template specifically used to form a skeleton of silica precursors such as fumed silica and silica sol, alumina precursors such as pseudoboehmite and aluminum isoprooxide, phosphoric acid and molecular sieves. Tetraethylammonium hydroxide (TEAOH), morpholine, triethylamine, isopropylamine, dipropylamine, diethylamine and the like are used.

This SAPO series molecular sieve was synthesized and presented for the first time by Union Carbide Co. (US Pat. Nos. 4,310,440, 4,440,871). In addition, the literature for producing light olefins (C ₂ to C ₄ olefins) from oxygen-containing compounds including methanol using SAPO-34 catalyst is known [US Pat. Nos. 4,440,871, 4,499,327] such as UOP and Exxon Mobil. SAPO-34 molecular sieve catalysts are widely used by major companies as reaction catalysts for the production of light olefins from methanol.

In addition, various methods have been studied to improve the activity and lifespan of the catalyst for the conversion of light olefins from methanol, and UOP Co., Ltd. is commonly known in zeolite catalysts to hydrothermally treat SAPO-34 catalysts at a high temperature of about 700 ° C. Has been shown to improve the selectivity and catalyst life [US Pat. No. 5,095,163] and Exxon Mobil has reported that acid treatment of SAPO-34 can improve the yield of light olefins, especially ethylene [US Pat. No. 5,475,182]. number].

In addition, UOP has reported various metal-substituted aluminophosphate molecular sieves as a method of increasing the yield of light olefins and increasing the activity of the catalyst in methanol to light olefin (Methanol to Olefin, MTO) reaction. As the silicon, magnesium, cobalt, zinc, iron, nickel, manganese, chromium or a mixture thereof is used (US Patent Nos. 5,126,308 and 5,191,141). In this case, silicon is the most preferred metal, the molecular sieve crystals of less than 1.0 ㎛ 50% by weight and particles larger than 2.0 ㎛ made of less than 10% by weight of the total, the content of silicon is 0.005 ~ 0.05 It was reported that the activity and durability of the catalyst were excellent when limited to the mole fraction. It has been reported that the yield of light olefins is increased when the mole fraction of the metal component is 0.02 to 0.08 and when the size of the molecular sieve crystal is 0.1 μm or more with respect to the aluminophosphate molecular sieve substituted with the same metal components [US Pat. No. 6,207,872,5,126,308]. ].

The present invention maintains and reacts the selectivity of light olefins having high ZSM-5 and SAPO-34 catalysts, which are used as catalysts for the conversion of oxygen compounds to prepare light olefins from oxygen compounds such as methanol. There is a problem in controlling the composition ratio of the product. Specifically, SAPO-34 has a high yield of ethylene in hard olefins, making it difficult to maintain a propylene / ethylene selectivity ratio of 1.0 or higher, whereas ZSM-5 has a high yield of propylene, allowing a propylene / ethylene selectivity ratio of 1.0 or higher. The high yield of heavy olefins of C ₅ or higher has a disadvantage in that the overall yield of light olefins in the range of C ₂ to C ₄ is low.

The present invention aims to provide a catalyst for preparing light olefins in which the yield of light olefins in the range of C ₂ to C ₄ is improved, and at the same time the propylene / ethylene selectivity ratio can be controlled to control the composition ratio of the reaction product.

The present invention is a step of preparing an alumina-silica mixture solution for ZSM-5 by mixing an aqueous alumina precursor solution and a silica precursor solution; Mixing the alumina-silica mixed solution for ZSM-5, tetrapropylammonium bromide (TPABr) and water, followed by adding an aqueous alkali hydroxide solution to prepare a synthetic gel for ZSM-5; Hydrothermal synthesis of the synthetic gel at 170 to 200 ° C. to produce crystalline ZSM-5; Mixing alumina precursor, silica precursor and tetraethylammonium hydroxide (TEAOH) to prepare an alumina-silica mixture for SAPO-34; A five step of preparing a ZSM-5 / SAPO-34 composite synthetic gel by mixing the alumina-silica mixture for SAPO-34 in four steps, crystalline ZSM-5 in three steps, phosphoric acid and water; And a six step of preparing a ZSM-5 / SAPO-34 composite catalyst by hydrothermally synthesizing the ZSM-5 / SAPO-34 composite gel at 170 to 200 ° C., drying at 100 to 150 ° C., and calcining at 500 to 700 ° C. It is characterized by a method for producing a ZSM-5 / SAPO-34 composite catalyst for producing light olefins.

In addition, the present invention is a ZSM-5 / SAPO-34 composite catalyst obtained by the above production method, the 2θ values obtained by X-ray diffraction analysis (XRD) is 7.9, 9.5, 15.9, 20.6, 23.1 and 30.0, SAPO-34 The ZSM-5 / SAPO-34 composite catalyst has a feature of maintaining a weight ratio of 1 to 9.9 relative to ZSM-5 and having a multi-pore structure having a surface area of 400 to 700 m 2 / g.

The present invention is light olefins which under the ZSM-5 / SAPO-34 composite catalyst obtained by the production method of the above, by reacting a Oxygenated compounds of C ₁ ~ C ₄ (oxygenates) producing an olefin of C ₂ ~ C ₄ range There is another feature of the manufacturing method.

When the light olefin conversion of the oxygenates is carried out under the ZSM-5 / SAPO-34 complex catalyst obtained by the method according to the present invention, the overall reaction yield is improved to 80% or more, and the propylene / ethylene ratio is improved. Selectivity can be controlled by maintaining more than 1.0, and the efficiency of the reaction can be improved by maintaining the long life of the catalyst.

The present invention is to prepare a ZSM-5 / SAPO-34 composite catalyst by a series of processes of crystalline ZSM-5 prepared by hydrothermal synthesis and the ZSM-5 in the reaction of SAPO-34, hydrothermal synthesis and calcining The present invention relates to a method for preparing light olefins by performing a light olefin conversion of oxygenates using the ZSM-5 / SAPO-34 complex catalyst.

Conventionally, ZSM-5 and SAPO-34, etc. are widely known as catalysts for preparing light olefins, but each catalyst has disadvantages such as maintaining high selectivity of light olefins and controlling the composition ratio of reaction products. The present invention is to improve these disadvantages and to prepare a complex catalyst by chemical synthesis rather than simply using a mixture of their catalysts, ZSM-5 due to the high acidity and large pore structure of ZSM-5 in the case of physical mixing The reaction influence of -5 is very high, and the production of heavy olefins increases, so that light olefin selectivity of C ₂ to C ₄ is relatively low. However, when the compound is manufactured by the chemical synthesis as described above, the surface scattering point and pore structure of the ZSM-5 are optimized and the pore structure of ZSM-5 is reduced and the pore structure is optimized. By the effect, the light olefin selectivity up to C ₂ to C ₄ becomes high.

In particular, the chemical synthesis is performed to maintain a specific process order so that the crystallinity of ZSM-5 and SAPO-34 appear at the same time, if the specific order is not maintained, the synthesis conditions of each of ZSM-5 and SAPO-34 In this case, crystallinity does not appear simultaneously.

The method for producing a ZSM-5 / SAPO-34 composite catalyst according to the present invention is a series of processes of hydrothermal synthesis and calcining after mixing the crystalline ZSM-5 prepared by hydrothermal synthesis in the process for producing SAPO-34 To perform.

First, to prepare a crystalline ZSM-5, which is generally used in the art, to prepare an alumina-silica mixture solution for ZSM-5 by mixing an aqueous alumina precursor solution and a silica precursor solution. At this time, the mixing is carried out at 10 to 50 ℃.

The alumina precursor and the silica precursor are generally used in the art, but are not particularly limited. Specifically, the alumina precursor may include nitrate, hydrochloride, sulfate, aluminum alkoxide, boehmite, alumina sol, etc. of the aluminum, and the silica precursor may be used. Silicates, water glass, silica sol and the like can be used.

They are used to maintain a 30 to 500 molar ratio of silica (SiO ₂ ) to alumina (Al ₂ O ₃ ). If the amount is less than 30 molar ratios, it is difficult to synthesize ZSM-5 and lower light olefin selectivity and 500 molar ratios. Even if it exceeds the ZSM-5 synthesis is difficult problem is good to maintain the above range.

Next, after mixing the alumina-silica mixed aqueous solution for ZSM-5, tetrapropylammonium bromide (TPABr) and water, an aqueous alkali hydroxide solution is added to prepare a synthetic gel for ZSM-5. At this time, the mixing and addition is carried out at 10 to 50 ℃, and stirred for 30 minutes to 5 hours after the addition of the aqueous alkali hydroxide solution.

The alkali hydroxide is not particularly limited to those generally used in the art, and specifically, sodium hydroxide, potassium hydroxide, and the like may be used.

Next, the synthetic gel is hydrothermally synthesized at 170 to 200 ° C. to produce crystalline ZSM-5. At this time, the hydrothermal synthesis time is maintained for 10 to 48 hours.

If the temperature is less than 170 ℃ crystal growth is slow, more crystallization time is required, if the temperature exceeds 200 ℃ problem occurs that the crystal size increases, if the reaction time is less than 10 hours, sufficient crystal growth does not occur crystallinity If it falls and exceeds 48 hours, it is preferable to maintain the above range because the catalyst synthesis time becomes too long to cause economic problems.

The hydrothermally synthesized ZSM-5 can be used in the preparation of a composite catalyst by adding ZSM-5 slurry after washing and dehydration or ZSM-5 dried at 100 to 150 ° C. to synthesize SAPO-34.

SAPO-34 preparation is commonly used in the art to prepare an alumina-silica mixture for SAPO-34 synthesis by mixing alumina precursor, silica precursor and tetraethylammonium hydroxide (TEAOH). At this time, the mixture is stirred and mixed for 30 minutes to 2 hours at a temperature of 10 to 50 ℃.

The alumina precursor and the silica precursor are generally used in the art, but are not particularly limited. Specifically, the alumina precursor may be an aluminum alkoxide such as pseudoboehmite, aluminum isopropoxide, aluminum triethoxide, and the like. As the silica precursor, silica sol, fumed silica, or the like can be used.

Since the silica (SiO ₂ ) to the alumina (Al ₂ O ₃ ) is used in the range of 0.05 to 1.0 mole ratio, when the amount is less than 0.05 mole ratio, it is difficult to synthesize SAPO-34, the reactivity of light olefins production is low, and it exceeds 1.0 mole ratio. Even if it is difficult to synthesize the SAPO-34 and the problem of low selectivity of the light olefin occurs, it is preferable to maintain the above range.

The tetraethylammonium hydroxide (TEAOH) is used in the range of 1.0 to 3.0 molar ratio with respect to alumina (Al ₂ O ₃ ). When the amount is less than 1.0 molar ratio, SAPO-34 is difficult to synthesize and exceeds 3.0 molar ratio. It is desirable to maintain this range because of the problem that catalyst synthesis is not economical.

Next, ZSM-5 / SAPO-34 composite gel is prepared by mixing the alumina-silica mixture for SAPO-34, ZSM-5 slurry obtained by hydrothermal reaction or dried ZSM-5, phosphoric acid and water. At this time, the temperature is carried out at 10 to 50 ℃ for 30 minutes to 2 hours.

The alumina-silica mixture for SAPO-34 is used in the range of 1 to 9.9 weight ratio with respect to ZSM-5 obtained by hydrothermal reaction. When the amount is less than 1 weight ratio, the yield of light olefin is lowered and the catalyst is greater than 9.9 weight ratio. It is desirable to maintain the above range because of the problem of low lifetime and propylene selectivity.

Next, the ZSM-5 / SAPO-34 composite gel was hydrothermally synthesized at 170 to 200 ° C. for 10 to 48 hours, then dried at 100 to 150 ° C., and calcined at 500 to 700 ° C. for 5 to 24 hours. To prepare a ZSM-5 / SAPO-34 composite catalyst. If the hydrothermal synthesis temperature is less than 170 ℃ SAPO-34 crystal growth may be slow crystallinity is lowered, if it exceeds 200 ℃ crystal size grows too large, there is a problem that the reactivity is poor, the firing temperature is 500 ℃ If it is less than the organic compounds used as a template may not be sufficiently removed, if it exceeds 700 ℃ it is preferable to maintain the above range because the problem of partial collapse of the crystallinity of the catalyst occurs.

The ZSM-5 / SAPO-34 composite catalyst prepared by the above method had 2θ values obtained by X-ray diffraction analysis (XRD) of 7.9, 9.5, 15.9, 20.6, 23.1 and 30.0, and SAPO-34 was added to ZSM-5. It maintains a weight ratio of 1 to 9.9 and has a multi-pore structure derived from ZSM-5 and SAPO-34, and the surface scattering point and pore inlet of ZSM-5 having a surface area of 400 to 700 m 2 / g are optimized and high C ₂ to Light olefin yield of C ₄ , in particular propylene selectivity.

On the other hand, the present invention is a hard to produce an olefin in the range of C ₂ ~ C ₄ by reacting C ₁ ~ C ₄ Oxygenates (oxygenates) under the ZSM-5 / SAPO-34 composite catalyst prepared by the above method There is another feature of the process for preparing olefins. In this case, the reaction is not particularly limited to those generally used in the art, but specifically, in the 250 to 550 ° C. temperature range, 0.5 to 10 atm, and the hourly space velocity per flow rate (WHSV) in the range of 0.1 to 50 hr ⁻¹ . It is good to do.

As described above, when a light olefin is prepared by converting oxygenated compounds using the ZSM-5 / SAPO-34 complex catalyst of the present invention, the selectivity of the light olefins in the C ₂ to C ₄ range is 70 to 95 carbon. It is in the mole% range, and the selectivity [C ₃ / C ₂ ] ratio of propylene to ethylene is in the range of 1.0 to 1.5.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited by the following examples.

Example 1

An aluminum nitrate solution was prepared by dissolving 1.37 g of aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O, 98%, Aldrich) in 23.25 mL of water, and separately Ludox HS-40 (40%, Aldrich) 19.15 as a silica precursor. g and 20 mL of water were mixed and slowly added to the aluminum nitrate solution. Next, the mixture was stirred at room temperature for 1 hour to prepare an alumina-silica mixed solution. Thereafter, 15 g of water was added to 6.93 g of tetralapropylammonium bromide (TPABr, 98%, Aldrich), which was slowly added to the alumina-silica mixed solution prepared above, and stirred at room temperature for 1 hour. Then, to the solution, a sodium hydroxide aqueous solution containing 1.03 g of sodium hydroxide (NaOH, 99%, Jin) and 17.5 g of water was slowly added and stirred for 1 hour, thereby ZSM- having a SiO ₂ / Al ₂ O ₃ molar ratio of 70. 5 synthetic gels were prepared.

The synthetic gel was placed in an autoclave and heated for 48 hours at 170 ° C. with stirring, the unreacted amorphous material was separated and separated using a centrifuge to obtain the ZSM-5 of the crystalline portion, and several times with water. Washing and recovery afforded crystalline ZSM-5.

Separately, 26.0 g of tetraethylammonium hydroxide (TEAOH, 35%, Aldrich) was added to 12.5 g of aluminum isopropoxide (Al ₂ (SO ₄ ) ₃ , 98%, Aldrich) and allowed to stand at room temperature for 1 hour. After stirring, 0.565 g of fumed silica (99.9%, Aldrich) was added thereto, followed by complete dissolution while stirring at room temperature for 1 hour to prepare a mixed solution. The prepared ZSM-5 composite was slowly added to the mixed solution with slow stirring. Thereafter, 7.0 g of phosphoric acid (85%, Samchun) and 28.0 mL of water were slowly added with stirring, followed by stirring for 2 hours to prepare a ZSM-5 / SAPO-34 composite synthetic gel.

The composite synthetic gel was placed in an autoclave and hydrothermally synthesized at 175 ° C. for 48 hours while stirring, to separate unreacted amorphous material and to obtain a ZSM-5 / SAPO-34 complex of crystalline portion. Separated and washed several times with water. Thereafter, dried at 110 ℃, the firing process for 10 hours while blowing air at 600 ℃ to prepare a final ZSM-5 / SAPO-34 composite catalyst. At this time, the ZSM-5 / SAPO-34 composite maintained a 1: 1 ratio of ZSM-5 and SAPO-34.

Example 2

ZSM-5: SAPO-34 = 1: 3 weight ratio ZSM-5: SAPO-34 = 1: 1 weight ratio of ZSM-5 / SAPO-34 composite catalyst was carried out in the same manner as in Example 1 A -5 / SAPO-34 complex catalyst was prepared.

Example 3

The same manner as in Example 1, except that the content ratio of the ZSM-5 / SAPO-34 composite is ZSM-5: SAPO-34 = 1: 1 weight ratio ZSM-5: SAPO-34 = 1: 6 weight ratio A 5 / SAPO-34 complex catalyst was prepared.

Example 4

In the same manner as in Example 1, ZSM-5: SAPO-34 = 1: 1 weight ratio of ZSM-5 / SAPO-34 = 1: 1 weight ratio of ZSM-5 / SAPO-34 composites instead of ZSM- A 5 / SAPO-34 complex catalyst was prepared.

Example 5

ZSM-5: SAPO-34 = 1: 1 ratio of ZSM-5: SAPO-34 = 1: 1 using ZSM-5 crystallized, filtered and washed with ZSM-5 sufficiently dry at 110 ° C after ZSM-5 crystallization, filtration and washing. A 5 / SAPO-34 complex catalyst was prepared.

Comparative Example 1

ZSM-5 / SAPO-34 mixed catalysts were prepared by uniformly physically mixing ZSM-5 and SAPO-34 prepared by the method described in Example 1 in a 1: 1 weight ratio.

Comparative Example 2

The ZSM-5 / SAPO-34 mixed catalyst was prepared by uniformly physically mixing ZSM-5 and SAPO-34 prepared by the method described in Example 1 in a 1: 6 weight ratio.

Comparative Example 3

The ZSM-5 / SAPO-34 mixed catalyst was prepared by uniformly physically mixing ZSM-5 and SAPO-34 prepared by the method described in Example 1 at a weight ratio of 1: 9.

Comparative Example 4

In the same manner as in Example 1, except that the crystalline ZSM-5 is not mixed during the preparation of SAPO-34, but the prepared SAPO-34 is mixed during the preparation of the ZSM-5, and the SAPO-34: ZSM-5 = 1: A 1 weight ratio SAPO-34 / ZSM-5 composite catalyst was prepared.

First, 26.0 g of tetraethylammonium hydroxide (TEAOH, 35%, Aldrich) is added to 12.5 g of aluminum isopropoxide (Al ₂ (SO ₄ ) ₃ , 98%, Aldrich), and the mixture is sufficiently stirred at room temperature for 1 hour. After stirring, 0.565 g of fumed silica (99.9%, Aldrich) was added thereto and dissolved completely with stirring at room temperature for 1 hour. Thereafter, 7.0 g of phosphoric acid (85%, Samchun) and 28.0 mL of water were slowly added to the mixed solution with stirring, followed by stirring for 2 hours to prepare a SAPO-34 synthetic solution. The thus prepared SAPO-34 synthetic solution was placed in an autoclave and hydrothermally synthesized at 175 ° C. for 48 hours while stirring. Thereafter, the unreacted amorphous material was separated and separated using a centrifuge to obtain the crystalline portion of SAPO-34, washed several times with water to obtain a SAPO-34 slurry.

Separately, 1.37 g of aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O, 98%, Aldrich) was dissolved in 23.25 mL of water to prepare an aqueous aluminum nitrate solution, and Ludox HS-40 (40%, Aldrich) as a silica precursor. 19.15 g and 20 mL of water were mixed and slowly added to an aqueous aluminum nitrate solution. Thereafter, the mixture was stirred at room temperature for 1 hour to prepare an alumina-silica mixed solution, which was mixed with the prepared SAPO-34 slurry to prepare a mixed solution. Next, 6.93 g of tetrapropylammonium bromide (TPABr, 98%, Aldrich) and 15 g of water were slowly added to the mixed solution prepared above, and stirred at room temperature for 1 hour. Thereafter, sodium hydroxide (NaOH, 99%, Jin) was added to 1.03 g of sodium hydroxide aqueous solution to which 17.5 g of water was added slowly, followed by stirring for 1 hour to prepare a SAPO-34 / ZSM-5 composite synthetic gel.

The composite synthetic gel was placed in an autoclave and hydrothermally synthesized at 175 ° C. for 48 hours while stirring to obtain a ZSM-5 / SAPO-34 composite, which separates the unreacted amorphous material and ZSM-5 / of the crystalline portion. Centrifuge was used to obtain the SAPO-34 complex and washed several times with water. The ZSM-5 / SAPO-34 composite thus prepared was dried at 110 ° C. and then fired at 600 ° C. for 10 hours to prepare a final ZSM-5 / SAPO-34 composite.

Comparative Example 5

In the same manner as in Example 1, but without performing the hydrothermal synthesis step for the crystallization of ZSM-5, each of the synthetic gel for ZSM-5 and the synthetic gel of SAPO-34 each aged at 80 ℃ for about 10 hours, ZSM-5 / SAPO-34 composite catalyst was prepared by mixing and performing crystallization through hydrothermal synthesis at 170 ° C. at one time.

Comparative Example 6

In the same manner as in Example 1, except that SAPO-34 was prepared only ZSM-5.

Comparative Example 7

In the same manner as in Example 1, except ZSM-5 was prepared only SAPO-34.

Experimental Example

The conversion of methanol was performed using the catalysts obtained in Examples 1 to 5 and Comparative Examples 1, 2 and 5 to 7 to prepare light olefins. At this time, at a reaction temperature of 400 ° C. and atmospheric pressure, a methanol concentration of 10% by volume and a methanol reference space velocity (WHSV) of 1 hr ⁻¹ were maintained and performed in a 1/2 inch fixed bed reactor. Selectivity of the light olefins prepared by the conversion reaction and the conversion rate of methanol are shown in Table 1 below.

As shown in Table 1, Examples 1 to 5 of the conversion of light olefins from methanol using the ZSM-5 / SAPO-34 composite catalyst prepared according to the present invention are light olefins up to C ₂ to C ₄ The selectivity was 80 mol% or more, and it was confirmed that the ratio of propylene / ethylene was variously adjusted to 1.0 or more according to the content ratio of ZSM-5 / SAPO-34.

This is Comparative Example 1 to a simple physical mixture of ZSM-5 and SAPO-34 as shown in 3 will be unable to be obtained, and its catalyst are relatively of the ZSM-5 reaction influences much produce a heavy olefin also is very high, the C ₂ the choice of light olefins to _C-4 is determined that the road is decreased. As such, the ZSM-5 / SAPO-34 composite catalyst prepared by the method according to the present invention exhibits high light olefin selectivity compared to the catalyst prepared by physically mixing ZSM-5 and SAPO-34. The surface scattering point and pore structure of ZSM-5 are judged to be optimized, indicating the result.

In addition, Figure 1 shows the XRD results of the catalyst prepared in Examples 1 to 5 and Comparative Examples 4 to 5, Examples 1 to 5 according to the present invention is ZSM-5 (2θ = 7.9, 23.1, 30.0) and It can be seen that SAPO-34 (2θ = 9.5, 15.9, 20.6) has both crystallinity. However, in Comparative Examples 3 and 4, ZSM-5 crystallinity was not observed at all, and only weakly SAPO-34 crystallinity was observed, and it was found that the amorphous part occupied much. This is expected because the crystallization conditions of ZSM-5 are different from SAPO-34, and the proper ZSM-5 crystal formation atmosphere is not achieved according to the synthesis method.

1 shows the results of X-ray diffraction analysis (XRD) of the catalyst prepared in Examples 1 to 5 and Comparative Examples 4 to 5 according to the present invention.

Claims (9)

A first step of preparing an alumina-silica mixed solution for ZSM-5 by mixing an alumina precursor solution and a silica precursor solution; Mixing the alumina-silica mixed solution for ZSM-5, tetrapropylammonium bromide (TPABr) and water, followed by adding an aqueous alkali hydroxide solution to prepare a synthetic gel for ZSM-5; Hydrothermally synthesizing the synthetic gel at 170 to 200 ° C. and preparing a ZSM-5 slurry after washing and filtration; Mixing alumina precursor, silica precursor and tetraethylammonium hydroxide (TEAOH) to prepare an alumina-silica mixture for SAPO-34; Step 5 of preparing a ZSM-5 / SAPO-34 composite synthetic gel by mixing the alumina-silica mixture for SAPO-34 of step 4, ZSM-5, phosphoric acid and water of step 3; And Hydrothermal synthesis of the ZSM-5 / SAPO-34 composite gel at 170 to 200 ° C., drying at 100 to 150 ° C., and calcining at 500 to 700 ° C. to produce a ZSM-5 / SAPO-34 composite catalyst. Method for producing a ZSM-5 / SAPO-34 composite catalyst for producing light olefins, characterized in that consisting of. The method of claim 1, wherein the step of drying at 100 to 150 ℃ after the three-step reaction further comprises a method for producing a light olefin ZSM-5 / SAPO-34 composite catalyst. The method of claim 1, wherein the alumina-silica mixture solution for ZSM-5 is ZSM-5 for producing light olefins, characterized in that the silica (SiO ₂ ) to alumina (Al ₂ O ₃ ) is maintained in the range of 30 to 500 molar ratio. Method for preparing / SAPO-34 composite catalyst. The method of claim 1, wherein the alumina-silica mixture for SAPO-34 is a ZSM-5 / for the production of light olefins, characterized in that the silica (SiO ₂ ) to alumina (Al ₂ O ₃ ) maintains a range of 0.05 to 1.0 molar ratio. Process for preparing SAPO-34 complex catalyst. The method of claim 1, wherein the alumina-silica mixture for SAPO-34 is used in the range of 1 to 9.9 weight ratio based on ZSM-5. ZSM-5 / SAPO-34 composite catalyst obtained by the method of any one of claims 1 to 5, 2θ values obtained by X-ray diffraction analysis (XRD) were 7.9, 9.5, 15.9, 20.6, 23.1 and 30.0, and SAPO-34 maintained a weight ratio of 1 to 9.9 with respect to ZSM-5, and the surface area was 400 to 700 m 2 / g. ZSM-5 / SAPO-34 composite catalyst comprising a multi-pore structure. Under the ZSM-5 / SAPO-34 complex catalyst obtained by the method of any one of claims 1 to 5, C ₁ to C ₄ oxygenated compounds (oxygenates) to react to produce an olefin in the range of C ₂ ~ C ₄ Method for producing a light olefin, characterized in that. The method of claim 7, wherein the reaction is performed in a temperature range of 250 to 550 ° C., a range of 0.5 to 10 atm, and a flow rate per hour space velocity (WHSV) in a range of 0.1 to 50 hr ^−1. . 8. The method according to claim 7, characterized in that the selectivity of the light olefins in the C ₂ to C ₄ range is 70 to 95 carbon mole%, and the selectivity [C ₃ / C ₂ ] ratio of propylene to ethylene is in the range from 1.0 to 1.5. Method for producing light olefins.

Images