KR20090028018A - Synthesis method of silicoaluminophosphate molecular sieve(sapo-34)as a catalyst with high performance and stability for the production of light olefins and production method of light olefins thereof - Google Patents

Abstract

A method for manufacturing a silicoaluminophosphate molecular sieve with high performance and stability to manufacture of light olefins and a method for manufacturing the light olefins using the same are provided to increase MTO reactivity efficiency, catalyst life, and a catalyst synthesis yield by optimizing size of a crystal. A method for manufacturing a silicoaluminophosphate catalyst to manufacture of light olefins comprises the following steps of: manufacturing aluminum phosphate gel by mixing water, an alumina precursor, a phosphoric acid; adding an organic template is added in the aluminum phosphate gel; manufacturing synthesized gel by agitating the aluminum phosphate gel and the organic template; dissolving silica after mixing and agitating a DEA organic template and a silica precursor; mixing a silica-dissolved mixture with the synthetic gel; manufacturing SAPO-34 containing the organic template; and the manufacturing the SAPO-34 removed the organic template.

Description

Synthesis method of silicoaluminophosphate molecular sieve (SAPOO-3) as a catalyst with high performance for preparing light olefins having high activity and long life. and stability for the production of light olefins and production method of light olefins pretty}

The present invention relates to a hydrothermal process using tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), morpholine or a mixture thereof, and an organic template in which a predetermined amount of diethylamine (DEA) is mixed. Synthetic method lowers the content of expensive tetraethylammonium hydroxide, economically and at the same time has a large specific surface area, uniform crystal size distribution and excellent crystallinity of the catalyst having silicoaluminophosphate (SAPO) -34 crystal phase, and under the catalyst By carrying out the conversion reaction of C ₁ ~ C ₄ oxygenates (oxygenates) to maintain the conversion and yield more than the same as the conventional, and in particular, by improving the hydrothermal stability of the catalyst due to the improved crystallinity has excellent catalyst durability It relates to a process for producing light olefins.

Silicoaluminophosphate (SCOO) molecular sieves are used as adsorbents and catalysts, and as catalysts are used in processes such as fluidized bed catalytic cracking, hydrocracking, isomerization, multimerization, conversion of alcohols or ethers, and alkylation of aromatic compounds. Has been. In particular, the use of SAPO molecular sieves to convert alcohols or ethers to olefin products, in particular ethylene and propylene, is of greater interest in large commercial production facilities.

Specifically, the SAPO molecular sieve is a silicon precursor such as fumed silica or silica sol, and pseudoboehmite or aluminum isoprooxide as an aluminum precursor. It is mainly used as a precursor of phosphorus, and the organic template used to form the skeleton of the most important molecular sieve is TEAOH, morpholine, triethylamine, isopropylamine or dipropylamine ( dipropylamine), diethylamine and the like have been used.

SAPO-34 is a molecular sieve with the same structure as the chabazite (CHA) zeolite mineral, and the chabazite skeleton forms an ABC stacking arrangement when viewed perpendicular to the xyz axis, which is the symmetry of the rhombohedral. Two hexagon rings are formed.

SAPO family molecular sieves were synthesized for the first time by Union Carbide Co. (US Pat. Nos. 4,310,440, 4,440,871). The company is particularly well known for the production of light olefins (C ₂ to C ₄ olefins) from oxygenated compounds including methanol using SAPO-34 catalysts [US Pat. Nos. 4,440,871, 4,499,327], UOP and Exxon Mobil et al. SAPO-34 molecular sieve catalysts have been well developed by the same major companies as reaction catalysts for the production of light olefins from methanol. However, for the commercialization of this process, there is a great demand for further catalyst activity and life improvement and economical catalyst preparation.

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 generally known in zeolite catalysts, and light olefins are obtained by hydrothermally treating SAPO-34 catalyst at a high temperature of about 700 ° C. Has been reported to improve the selectivity and catalyst life [US Pat. No. 5,095,163], and Exxon Mobil, in US Pat. No. 5,475,182, can improve the yield of light olefins, especially ethylene, through acid treatment of SAPO-34. Reported.

Another method of increasing light olefin yield and increasing catalyst activity in methanol to light olefin reactions is UOP, Inc., in which U.S. Patent Nos. 5,126,308 and 5,191,141 are substituted with various metals. A nophosphate molecular sieve was reported, and metal, silicon, magnesium, cobalt, zinc, iron, nickel, manganese, chromium, or a mixture thereof was used. At this time, silicon is the most preferred metal, and when the size of the molecular sieve crystal is less than 1.0 μm of 50% and particles larger than 2.0 μm are made up of less than 10% of the total, the content of silicon is limited to 0.005 to 0.05 in mole fraction. It was reported that the activity and durability of the catalyst is excellent. In addition, U.S. Patent No. 6,207,872, an improved patent of No. 5,126,308, is used for aluminophosphate molecular sieves having the same metal components substituted when the mole fraction of the metal component is 0.02 to 0.08 and when the size of the molecular sieve crystals is 0.1 µm or more. The yield is reported to be high.

Regarding the preparation of SAPO-34 with small crystal size, US Pat. No. 6,773,688 reports that most particle sizes (more than 90%) can produce nanometer sized SAPO-34 molecular sieves smaller than 100 nm. In this case, the silicon source was dissolved in an organic base when making a synthetic gel to make the size of the silicon small, thus reducing the size of the synthesized SAPO-34 molecular sieve. In this patent, TEAOH alone or TEAOH and dipropylamine (DPA) were mixed and used as an organic template.

As mentioned in the prior patents, the SAPO-34 crystal size generally has a significant effect on the reactivity in the reaction for the preparation of olefins from methanol, and has been reported to have good reactivity when having a small crystal size of 1 μm or less. However, when the crystal size of SAPO-34 is small, there are disadvantages such as difficulty in filtering after synthesis and lowering of catalyst yield. Further, crystallinity is lowered, which may lower hydrothermal stability at high temperature. This can directly affect catalyst economics and catalyst life and must be improved. Therefore, it is required to optimize the crystal size having a suitable crystal size to maximize the reactivity and improve the catalyst stability by synthesizing SAPO-34 having excellent crystallinity.

Regarding the synthesis of SAPO-34 catalysts using the new template, US Pat. No. 6,620,983 used an organic template compound in which a fluoride source comprising at least two fluoride (F) substituents was combined to synthesize SAPO-34 molecular sieves. The SAPO-34 catalyst thus prepared was reported to have excellent activity in the MTO reaction. However, this SAPO molecular sieve is expensive in catalyst production by using an organic template containing fluoride, and fluorine-based organic templates have a high toxicity and corrosion resistance, and thus have problems in handling stability.

In conclusion, as described above, various methods have been proposed in the related patents for preparing SAPO-34 to increase the yield of light olefins and increase the life of the catalyst as MTO reaction catalysts for the production of light olefins in methanol. Methods include synthesis of SAPO-34 with small crystal size, post-treatment such as hydrothermal treatment or acid treatment after synthesis, or new template containing metal substitution and fluorine component during synthesis. In addition, many cases have been reported using one or more mixed template in the existing patent, but the effect of the MTO reaction is not specifically mentioned.

According to the present invention, the use of diethylamine (DEA) as a base template and the mixing of various templates and optimization of the composition of the template significantly improved MTO reaction performance and lifetime, as well as the expensive template tetraethylammonium. Economical MTO catalysts can be prepared by significantly reducing the amount of hydroxide (TEAOH) used or by no use at all.

In the present invention, aluminum phosphate gel is prepared by mixing water, alumina precursor and phosphoric acid, followed by tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), and triethylamine (TEA). 1 step of preparing a synthetic gel by adding an organic template of a morpholine or a mixture thereof and stirring at 10 to 50 ℃; Mixing the diethylamine (DEA) organic template with the silica precursor, stirring at a temperature of 10 to 50 ° C. to dissolve the silica, and then mixing with the synthetic gel of the first step; The mixed synthetic gel was placed in an autoclave and stirred at 20 to 120 ° C. for 0 to 24 hours, and then stirred at 175 to 200 ° C. for 5 to 48 hours. Three steps to prepare phosphate (SAPO) -34; And sintering SAPO-34 containing the organic template in an air atmosphere, 550-700 ° C., to prepare SAPO-34 from which the organic template has been removed. 34 It is characterized by the method of preparing the catalyst.

The present invention provides a mixed organic template comprising diethylamine as a basic organic template and at least one organic template selected from tetraethylammonium hydroxide, isopropylamine, dipropylamine, triethylamine, and morpholine. By preparing the SAPO-34 molecular sieve by hydrothermal synthesis, the MTO reactivity and catalyst life can be greatly increased, and the amount of expensive TEAOH used mainly in the conventional SAPO-34 molecular sieve production is greatly reduced or not used. By optimizing the size, the yield of catalyst synthesis can be greatly increased, thereby significantly reducing the cost of catalyst synthesis.

The present invention is characterized by a method for synthesizing SAPO-34 molecular sieves, which not only secures the economics of catalyst production by using two or more mixed template bodies containing diethylamine, but also greatly improves MTO reactivity and stability. .

Generally, SAPO-34 molecular sieves are prepared using expensive tetraethylammonium hydroxide (TEAOH). The TEAOH has a high crystallization capacity due to the small crystal size of the prepared molecular sieves, but the price is too high to be economical. In addition, the crystal size is too small, there is a difficulty in the catalytic purification and recovery process after synthesis, and the manufacturing process efficiency is low. In addition, it may have low hydrothermal stability due to small crystals, which may cause a problem in stability during continuous regeneration of the catalyst in the circulating fluidized bed reactor.

In the present invention, TEAOH is not used, or the amount of use thereof is drastically lowered, so that economic efficiency can be secured, reactivity performance and life can be greatly improved, and the use of a specific mixed template serves as a seed. The morphologies increase the crystallinity and enable the production of molecular sieves with optimized crystal size in the range of 1 to 5 μm.

Typically tetraethylammonium hydroxide, morpholine, triethylamine, cyclopentylamine, aminomethyl cyclohexane, piperidine, cyclohexylamine, tri-ethyl hydroxyethylamine, dipropylamine, pyridine, isopropylamine And the like are widely known in the art as organic templates (Korean Patent Registration No. 699654, Korean Patent Registration No. 699650). The present invention minimizes the amount used even if expensive tetraethylammonium hydroxide is used or not, thereby greatly improving the surface area and hydrothermal stability of the catalyst due to the optimum crystal size and excellent SAPO-34 crystallinity. The literature on how to make SAPO-34 in the same way is not known yet.

That is, in the case of using each of the organic template of the present invention except for the expensive tetraethylammonium hydroxide alone, the SAPO-34 crystal production efficiency is lowered, or the crystal size is too large even if a crystal is formed. Although there is a problem that the MTO reactivity performance and life is low because of a small amount, by using a mixture of these in a certain amount to solve the above problems as well as to maintain excellent crystallinity and optimum crystal size.

Hereinafter, a method for preparing silicoaluminophosphate (SAPO-34) molecular sieve according to the present invention will be described in detail.

First, aluminum phosphate gel was prepared by mixing water, alumina precursor, and phosphoric acid, and then tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), and triethylamine (TEA). , An organic template of morpholine or a mixture thereof is added and stirred to prepare a synthetic gel. The alumina precursor is generally used in the art, but is not particularly limited, and specifically, an aluminum alkoxide or pseudoboehmite may be used.

At this time, when the temperature is maintained in the range of 10 to 50 ℃ bar, if the temperature is less than 10 ℃ uniform dispersion and dissolution is difficult, if it exceeds 50 ℃ too fast gelation may occur difficult to disperse problems Therefore, it is good to maintain the above range.

Next, the diethylamine (DEA) organic template and the silica precursor are mixed, stirred at a temperature of 10 to 50 ° C. to dissolve the silica, and then mixed with the synthetic gel of the first step. The silica precursor is generally used in the art, but is not particularly limited, and specifically, water glass, silica sol, and fumed silica may be used.

The stirring and mixing is carried out at 10 to 50 ° C. for 30 minutes to 5 hours. When the temperature is less than 10 ° C., it is difficult to obtain a uniform gel. If the temperature is higher than 50 ° C., the synthetic gel is already a precursor of a specific crystalline phase. It is advisable to maintain this range as it progresses.

Next, the mixed synthetic gel is placed in an autoclave and aged while stirring at 20 to 120 ° C. for 0 to 24 hours, and then the organic template is contained by hydrothermal synthesis at 175 to 200 ° C. for 5 to 48 hours. To prepare prepared silicoaluminophosphate (SAPO) -34.

If the primary temperature is less than 20 ℃ synthetic gel aging effect is lowered, if it exceeds 120 ℃ maintain the above range as the crystallization starts beyond the aging step.

In addition, when the temperature is less than 175 ℃, the crystal growth of the SAPO-molecular sieve is slow and can be produced as a phase in which the amorphous portion and the crystalline SAPO-34 is mixed, when the temperature exceeds 200 ℃ SAPO-34 crystals are excessive When large growth is applied to the MTO reaction, the problem of shortening the life of the catalyst occurs.

Next, the SAPO-34 containing the organic template is fired in an air atmosphere at 550 to 700 ° C. to prepare the SAPO-34 from which the organic template is removed.

If the temperature is less than 500 ° C, the temperature is too low to completely remove the organic amine, and if it exceeds 700 ° C, the SAPO-34 crystal structure may be partially collapsed.

As described above, the present invention maintains the total amount of the organic template in the range of 1.0 to 4.0 molar ratio with respect to 1 mole of the alumina precursor (based on Al ₂ O ₃ ) in order to prepare the silica aluminophosphate (SAPO) -34 catalyst. If the amount is less than 1.0 molar ratio, the SAPO-34 crystal phase is difficult to obtain, and even if it exceeds 4.0 molar ratio, the SAPO-34 crystal phase may be difficult to obtain, and it is not preferable in terms of catalyst production economics.

The diethylamine which is a main component of the organic template is 0.5 to 3.5 molar ratio, preferably 1.0 to 2.0 molar ratio, with respect to 1 mole of alumina precursor (based on Al ₂ O ₃ ). If the SAPO-34 crystal is difficult to form and exceeds 3.5 molar ratio, the effect of the mixed template is reduced, the crystal size can be large, and the catalyst manufacturing cost increases, which is not preferable. In addition, the tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), triethylamine (TEA), morpholine or a mixture thereof is the main component diethylamine (DEA) It is used in the range of 0.01-1.3 molar ratio with respect to 1 mol, Preferably it is 0.1-1.0. If the amount is less than 0.01 molar ratio, the SAPO-34 average crystal size is 5 μm or more, and if it exceeds 1.3 molar ratio, the SAPO-34 crystallinity is poor or the SAPO-34 average crystal size is less than 1 μm. Since the problem larger than 5 micrometers arises, it is good to maintain the said range.

The silica aluminophosphate (SAPO) -34 prepared by the above method is 0.05 to 1.0 molar ratio of SiO ₂ / Al ₂ O ₃ , and P ₂ O ₅ / Al ₂ O ₃ to maintain the range of 0.7 to 1.3 molar ratio, respectively. Use ingredients in.

When the molar ratio of SiO ₂ to Al ₂ O ₃ is less than 0.05, the SAPO-34 crystal phase is difficult to obtain, the MTO reaction activity is low, and even when it exceeds 1.0, the SAPO-34 crystal phase is difficult to obtain and the MTO reaction selectivity. Problem occurs. In addition, when the molar ratio of P ₂ O ₅ to Al ₂ O ₃ is less than 0.7, not only is the SAPO-34 crystal phase difficult to obtain, but amorphous alumina is generated by excess alumina, and even when the molar ratio exceeds 1.3 molar ratio, SAPO-34 Not only is it difficult to obtain a crystal phase, but also a problem arises in that unreacted amorphous phosphate is generated by excess phosphoric acid.

In addition, silicoaluminophosphate (SAPO) -34 has an average crystal size in the range of 0.1 to 5 μm, a specific surface area in the range of 600 to 800 m 2 / g, and a particle size distribution of less than 1 μm in particle size of 0 to 20% by weight. Pure SAPO-34 catalyst particles as shown in the results of X-ray diffraction analysis (XRD) of FIG. Is prepared.

On the other hand, the present invention is another feature of the method for preparing a light olefin by reacting the C ₁ ~ C ₄ oxygen compounds (oxygenates) under the prepared silica aluminophosphate (SAPO) -34 catalyst. The reaction is not particularly limited to those generally used in the art, but is performed in the range of 250 to 550 ° C., 0.5 to 10 atmospheres, and an hourly space velocity per hour flow rate (WHSV) of 0.1 to 50 hr ⁻¹ .

The catalyst exhibits pure SAPO-34 crystallinity, and thus exhibits excellent catalytic activity, maintaining conversion and yields equal to or higher than those of the prior art. It has excellent catalyst durability. In addition, the crystal of the catalyst is excellent to improve the hydrothermal stability, the hydrothermal stability of this catalyst shows the most important catalytic properties when the catalyst is applied to the circulating fluidized bed reactor.

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

To 19.9 g of aluminum isopropoxide (98%, Aldrich) was added 20.0 g of tetraethylammonium hydroxide (TEAOH, 35%, Aldrich). Subsequently, 11.0 g of phosphoric acid (85%, Samchun) and 43 mL of water were slowly added dropwise with stirring to the aluminum isopropoxide solution for 2 hours, and then the mixture was sufficiently stirred at room temperature for 1.5 to 5 hours. A phosphate solution was prepared.

Separately, 0.86 g of fumed silica (99.9%, Aldrich) was added to 3.51 g of diethylamine (DEA, 99.5%, Aldrich) and completely dissolved by stirring at room temperature (20 ° C.) for 2 hours.

The silica solution prepared above was added to the aluminum phosphate mixture and stirred for 1 to 5 hours. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DEA: 1.0 TEAOH: 50 H ₂ O to prepare a SAPO-molecular sieve.

The gel solution was placed in an autoclave and heated at 200 ° C. for 24 hours with stirring. The SAPO-molecular sieve prepared above was separated by using a centrifuge to separate the unreacted material and to obtain the SAPO-molecular sieve of the crystalline portion, and washed with water several times. The SAPO-molecular sieve prepared above was dried at 110 ° C. to obtain a powder, and SAPO-34 was prepared by sufficiently firing for 10 hours while blowing air at 600 ° C. to remove the template.

Example 2

In the same manner as in Example 1, using 7.0 g of diethylamine (DEA, 99.5%, Aldrich), the composition of the reaction gel was 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DEA: SAPO-molecular sieves were prepared at a molar ratio of 1.0 TEAOH: 50 H ₂ O.

Example 3

The same procedure as in Example 1, except that 2.83 g of isopropylamine (IPA, 99%, Junsei) was used instead of tetraethylammonium hydroxide (TEAOH), and diethylamine (DEA, 99.5%, Aldrich) 7.0 SAPO-34 was prepared using g. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DEA: 1.0 IPA: 50 H ₂ O SAP- molecular sieve.

Example 4

In the same manner as in Example 1, 4.84 g of dipropylamine (DPA, 99%, Aldrich) was used instead of tetraethylammonium hydroxide (TEAOH), and diethylamine (DEA, 99.5%, Aldrich). SAPO-34 was prepared using 7.0 g. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DEA: 1.0 DPA: 50 H ₂ O SAP- molecular sieve.

Example 5

The same procedure as in Example 1 except that 4.84 g of triethylamine (TEA, 99%, Junsei) was used instead of tetraethylammonium hydroxide (TEAOH), and diethylamine (DEA, 99.5%, Aldrich) 7.0 SAPO-34 was prepared using g. In this case, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DEA: 1.0 TEA: 50 H ₂ O SAP- molecular sieve.

Example 6

In the same manner as in Example 1, SAPO-34 was prepared using 4.17 g of morpholine (99%, Aldrich) instead of tetraethylammonium hydroxide (TEAOH). At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DEA: 1.0 morpholine: 50 H ₂ O to prepare a SAPO-molecular sieve.

Example 7

In the same manner as in Example 1, 10.0 g of tetraethylammonium hydroxide (TEAOH) and 1.41 g of isopropylamine (IPA, 99%, Junsei) were used instead of 20.0 g of tetraethylammonium hydroxide (TEAOH). Mixing was used to prepare SAPO-34. In this case, the composition of the reaction gel was prepared using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DEA: 0.5 IPA: 0.5 TEAOH: 50 H ₂ O to prepare a SAPO-molecular sieve.

Example 8

In the same manner as in Example 1, instead of 20.0 g of tetraethylammonium hydroxide (TEAOH), 2.42 g of dipropylamine (DPA, 99%, Aldrich) and 1.41 g of isopropylamine (IPA, 99%, Junsei) Was used to prepare SAPO-34. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DEA: 0.5 IPA: 0.5 DPA: 50 H ₂ O to prepare a SAPO-molecular sieve.

Comparative Example 1

The same procedure as in Example 1, except that 40.0 g of tetraethylammonium hydroxide (TEAOH) was used to prepare SAPO-molecular sieve. At this time, the composition of the reaction gel was prepared SAPO-molecular sieve using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 TEAOH: 50 H ₂ O.

Comparative Example 2

The same procedure as in Example 1, except that 7.0g of diethylamine (DEA) was used to prepare a SAPO-molecular sieve. At this time, the composition of the reaction gel was prepared SAPO-molecular sieve using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DEA: 50 H ₂ O.

Comparative Example 3

The same procedure as in Example 1, except that 5.66 g of isopropyl alcohol (IPA) was used to prepare SAPO-molecular sieve. At this time, the composition of the reaction gel was prepared SAPO-molecular sieve using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 IPA: 50 H ₂ O.

Comparative Example 4

The same procedure as in Example 1 was carried out except that the SAPO-molecular sieve was prepared using dipropylamine (DPA) 9.68 alone. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 DPA: 50 H ₂ O SAP- molecular sieve.

Comparative Example 5

The same procedure as in Example 1, except that triethylamine (TEA) 9.68 was used to prepare a SAPO-molecular sieve. At this time, the composition of the reaction gel was prepared SAPO-molecular sieve using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 TEA: 50 H ₂ O.

Comparative Example 6

The same procedure as in Example 1, except that the SAPO-molecular sieve was prepared using 8.34 g of morpholine alone. In this case, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 2.0 morpholine: 50 H ₂ O to prepare a SAPO-molecular sieve.

Comparative Example 7

In the same manner as in Example 1, but instead of tetraethylammonium hydroxide (TEAOH), SAPO-34 was prepared using 2.83 g of isopropylamine (IPA, 99%, Junsei). At this time, the composition of the reaction gel was prepared SAPO-molecular sieve using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.3 DEA: 1.8 IPA: 50 H ₂ O.

Comparative Example 8

In the same manner as in Example 1, 4.84 g of dipropylamine (DPA, 99%, Aldrich) was used instead of tetraethylammonium hydroxide (TEAOH), and 4.22 g of diethylamine (DEA, 99.5%, Aldrich). SAPO-34 was prepared using g. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.3 DEA: 1.8 DPA: 50 H ₂ O to prepare a SAPO-molecular sieve.

Comparative Example 9

In the same manner as in Example 1, except that tetraethylammonium hydroxide (TEAOH) was used to prepare SAPO-34 using 4.84 g of triethylamine (TEA, 99%, Junsei). At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.3 DEA: 1.8 TEA: 50 H ₂ O to prepare a SAPO-molecular sieve.

Comparative Example 10

In the same manner as in Example 1, SAPO-34 was prepared using 2.83 g of isopropylamine (IPA, 99%, Junsei) instead of diethylamine (DEA). At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 TEAOH: 1.0 IPA: 50 H ₂ O to SAPO-molecular sieve.

Comparative Example 11

In the same manner as in Example 1, 4.84 g of dipropylamine (DPA, 99%, Aldrich) was used instead of tetraethylammonium hydroxide (TEAOH), and isopropylamine (DEA) was used instead of diethylamine (DEA). IPA, 99%, Junsei) was prepared using 2.83 g of SAPO-34. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DPA: 1.0 IPA: 50 H ₂ O to SAPO-molecular sieve.

Comparative Example 12

In the same manner as in Example 1, 4.84 g of dipropylamine (DPA, 99%, Aldrich) was used instead of tetraethylammonium hydroxide (TEAOH), and triethylamine (DEA) was used instead of triethylamine (DEA). TEA, 99%, Junsei) was used to prepare SAPO-34. At this time, the composition of the reaction gel was prepared by using a molar ratio of 1.0 Al ₂ O ₃ : 1.0 P ₂ O ₅ : 0.3 SiO ₂ : 1.0 DPA: 1.0 TEA: 50 H ₂ O SAP- molecular sieve.

As a result of elemental analysis of the SAPO-molecular sieves prepared in Examples 1 to 8 and Comparative Examples 1 to 12, the specific surface area, crystal form, average crystal size, crystal distribution, and synthetic yield are summarized in Table 1 below.

As shown in Table 1 and FIG. 2, Examples 1 to 8 according to the present invention used DEA as a first template and a mixture of TEAOH, IPA, DPA, TEA, morpholine, or a mixture thereof as a second template. It was confirmed that due to the effect of the mixed template, molecular sieves of pure SAPO-34 crystal phase were all produced.

In addition, it can be seen that the crystal size is uniform because the average crystal size is present in more than 80% of the particles maintaining the range of 1 to 5 ㎛. On the other hand, as can be seen in Table 1 and Figure 3, Comparative Examples 1 to 6 is a case of using a single template, Comparative Example 1 is a crystal of SAPO-34 was well formed, but the average crystal size is about 0.3 ㎛ It can be seen that small crystals are formed. This is a factor that lowers the synthesis yield of the catalyst, and because the price of TEAOH is very high, the cost of producing the catalyst may be the biggest difficulty in commercialization of the catalyst. It can be seen that Comparative Examples 2 and 6 have excellent crystallinity and uniform crystal formation of SAPO-34, but the average crystal size is somewhat larger than 7 μm, and Comparative Examples 3, 4 and 5 form pure SAPO-34 crystals. The average crystal size of the formed SAPO-34 is not less than 10 μm. This may cause a decrease in reactivity.

When the single template of Comparative Examples 1 to 6 was used, it was confirmed that SAPO-34 crystallinity was inferior, and that the crystal size was too small (less than 1 μm or more than 5 μm) in many cases.

In Comparative Examples 7 to 12, a mixed template was used, and electron micrographs of these particles are shown in FIG. 5. Specifically, Comparative Examples 7 to 9 show that the crystal size and crystallinity of the SAPO molecular sieve vary greatly according to the molar ratio of the two templates when IPA, DPA and TEA are used as the second template for the first template DEA. When the molar ratio of IPA to DEA is about 1.4, SAPO-34 crystals are formed, but the average crystal size is somewhat larger than 7.5 μm, and when the second template is DPA or TEA, the molar ratio of the two template to DEA is about 1.4 In this case, SAPO-11 and SAPO-5 are formed more than SAPO-34. Thus, it can be seen that there is a mixed template composition range capable of forming an optimal SAPO-34.

Comparative Examples 10 to 12 are cases in which a mixed template containing no DEA is used among the templates used in the present invention to be compared with the case where DEA is used as the first template. In Comparative Example 10, a mixture of IPA and TEAOH is used. In this case, the crystals of SAPO-34 were well formed, but the average crystal size was about 7.5 μm, indicating that many large crystals exceeding 5 μm were formed.

 Comparative Examples 11 and 12 synthesized SAPO-34 using DPA as a first template and IPA and TEA as another second template. DPA and IPA acted independently without showing the effect of the mixed template of Comparative Example 11. As a result, the crystallinity of SAPO-34 is inferior and the crystal size is mostly 5 µm or more, which is somewhat large. This is because DPA and TEAOH do not mix well with each other. In addition, Comparative Example 12 has some amorphous, and it can be seen that the crystal size of SAPO-34 is very large unlike other mixed templates.

Even though mixed molds are used, the effect of mixed molds such as crystallinity and crystallite size of SAPO-34 is very different depending on the composition and type of each mold, and uniformity between 1 and 5 μm by using mixed molds containing DEA. One SAPO-34 crystal can be synthesized.

Experimental Example

Using the molecular sieves prepared in Examples 1 to 8 and Comparative Examples 1 to 12, the reaction temperature was 400 ° C., and the methanol reference space velocity (WHSV) was 1 / hr ⁻¹ under a condition of 10% by volume of methanol diluted with nitrogen. Light olefin conversion (MTO) from methanol was performed in a 2 inch fixed bed reactor. At this time, the initial conversion reaction (MTO) result is the result 20 minutes after the start of the reaction to stabilize the initial reaction conditions, the catalyst life is based on the time when the MeOH conversion is reduced by more than 5% and the sum of ethylene and propylene yield is 75% or less (See Table 2). In addition, in order to confirm the difference in the hydrothermal stability of the catalyst, the reaction performance change was observed after treating Example catalysts and Comparative Example 1 with 10% steam at 700 ° C. for 12 hours (see Table 3).

division Initial Methanol Conversion (%) Initial ethylene selectivity (%) Initial Propylene Selectivity (%) Catalyst Life ^*) (hours) Example 1 99 49.7 36.7 More than 15 Example 2 99 49.3 36.9 More than 15 Example 3 99 49.5 34.3 6 Example 4 98 49.0 33.7 5 Example 5 97 51.4 36.2 7 Example 6 98 49.0 34.5 5 Example 7 98 52.9 35.4 More than 15 Example 8 98 50.0 30.6 3 Comparative Example 1 99 46.5 38.0 3 Comparative Example 2 30 57.0 26.5 0.5 or less Comparative Example 3 47 11.7 11.6 Comparative Example 4 63 9.3 9.4 Comparative Example 5 67 33.3 31.2 Comparative Example 6 95 35.9 31.7 Comparative Example 7 99 50.8 32.3 1.5 Comparative Example 10 99 46.0 34.2 1 or less Comparative Example 11 92 32.9 22.6 0.5 or less Comparative Example 12 52 21.2 15.7 *) Catalyst life: Time when conversion rate is reduced by more than 5% and ethylene and propylene yields are less than 75%

division Initial Methanol Conversion Rate after Steam Treatment (%) Initial ethylene selectivity after steaming (%) Initial propylene selectivity after steaming (%) Catalyst life after steam treatment ^*) (hours) Example 1 98 45.6 34.2 More than 15 Example 2 99 46.3 34.3 More than 15 Example 3 97 45.5 32.3 5 Example 4 97 45.8 31.6 4 Example 5 98 47.4 34.1 6 Example 6 97 46.1 32.7 5 Example 7 98 48.8 33.4 More than 15 Example 8 97 48.2 30.8 2 Comparative Example 1 90 42.3 33.0 1.5 *) Catalyst life: Time when conversion rate is reduced by more than 5% and ethylene and propylene yields are less than 75%

As shown in Tables 2 and 3 above, the molecular sieves of Examples 1 to 9 using the mixed template according to the present invention had a conversion rate, selectivity of ethylene and propylene, and a catalyst compared to Comparative Examples 2 to 6 using a single template. It was confirmed that the lifespan and the like are excellent.

In particular, it can be seen that the representative SAPO-34 template and the small crystal size show superior catalytic activity despite the larger crystal size than the SAPO-34 catalyst using TEAOH, which is known to be the best in the performance of the olefin conversion reaction. Of these examples 1 and 7 show very high catalyst life of at least 15 hours. In Comparative Examples 7 to 12, a mixed template was used, and it can be seen that the effect of improving the performance of the olefin conversion reaction greatly differs depending on the type and composition of the mixed template. In particular, it can be seen that there are optimum properties in crystallinity and crystal size. It can be seen that the reactivity of SAPO-34 having a crystal size larger than 5 μm is significantly lower. In addition, it can be seen that when the crystal size is smaller than 1 μm, the crystallinity is low and the hydrothermal stability is significantly low.

1 shows X-ray diffraction analysis (XRD) of the SAPO catalysts prepared in Examples 1 to 8 and Comparative Example 1 according to the present invention.

Figure 2 shows an electron micrograph (SEM) of the SAPO catalysts prepared in Examples 1 to 8 according to the present invention, (A) Example 1, (B) Example 2, (C) Example 3, ( D) Example 4, (E) Example 5, (F) Example 6, (G) Example 7, and (H) Example 8.

Figure 3 shows an electron microscope (SEM) photograph of the SAPO catalysts prepared in Comparative Examples 1 to 6, (A) Comparative Example 1, (B) Comparative Example 2, (C) Comparative Example 3, (D) Comparative Example 4, (E) Comparative Example 5, (F) Comparative Example 6, (G) Comparative Example 7, (H) Comparative Example 8, (I) Comparative Example 9, (J) Comparative Example 10, (K) Comparative Example 11 And (L) Comparative Example 12.

Claims (8)

Water, alumina precursor and phosphoric acid were mixed to prepare an aluminum phosphate gel, followed by tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), triethylamine (TEA), morpholine Or adding an organic template of a mixture thereof and stirring at 10 to 50 ° C. to prepare a synthetic gel; Mixing the diethylamine (DEA) organic template with the silica precursor, stirring at a temperature of 10 to 50 ° C. to dissolve the silica, and then mixing with the synthetic gel of the first step; The mixed synthetic gel was placed in an autoclave and stirred at 20 to 120 ° C. for 0 to 24 hours, and then stirred at 175 to 200 ° C. for 5 to 48 hours. Three steps to prepare phosphate (SAPO) -34; And Four steps to prepare the SAPO-34 from which the organic template is removed by firing the SAPO-34 containing the organic template in the air atmosphere, 550 ~ 700 ℃ range Method for producing a silica aluminophosphate (SAPO) -34 catalyst for the production of light olefins comprising a. The catalyst of claim 1 wherein the silicoaluminophosphate (SAPO) -34 catalyst is SiO ₂ / Al ₂ O ₃ is 0.05 to 1.0 molar ratio, P / Al is maintained in the range of 0.7 to 1.3 molar ratio. The method of claim 1, wherein the organic template used in steps 1 and 2 is used in a range of 1.0 to 4.0 molar ratio with respect to 1 mole of alumina precursor (based on Al ₂ O ₃ ). The method of claim 1, wherein the diethylamine (DEA) is used in an amount of 0.5 to 3.5 molar ratios based on 1 mole of the alumina precursor (based on Al ₂ O ₃ ). The method of claim 1, wherein tetraethylammonium hydroxide (TEAOH), dipropylamine (DPA), isopropylamine (IPA), triethylamine (TEA), morpholine or mixtures thereof is diethylamine (DEA). It is used in 0.01-1.3 molar ratio with respect to 1 mol, The manufacturing method of the catalyst characterized by the above-mentioned. The method according to claim 1, wherein the silica aluminophosphate (SAPO) -34 catalyst has an average crystal size of 1 to 5 ㎛ range, specific surface area of 600 to 800 m 2 / g, Crystal size distribution ranges from 0 to 20% by weight of particle size of less than 1 μm, 60 to 100% by weight of particle size of 1 to 5 μm, and 0 to 20% by weight of particle size of more than 5 μm. . A method for producing light olefins, characterized in that C ₁ to C ₄ oxygenates are reacted under a silicon aluminophosphate (SAPO) -34 catalyst obtained by the process according to any one of claims 1 to 6. . The method of claim 7, wherein the reaction is performed at a temperature of 250 to 550 ° C., 0.5 to 10 atmospheres, and a flow rate per hour space velocity (WHSV) of 0.1 to 50 hr ⁻¹ .

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