CN1298426C - A modified bicomponent molecular sieve and catalytic cracking catalyst - Google Patents

Abstract

The invention relates to a modified bi-component molecular sieve and a catalytic cracking catalyst, wherein the modified bi-component molecular sieve is obtained by modifying the bi-component molecular sieve, and the modified bi-component molecular sieve is obtained by Na in percentage by weight₂0.1 to 2.5% of O and RE₂O₃0-4% of modified molecular sieve; the catalytic cracking catalyst comprises, by weight, 25-40% of a modified bi-component molecular sieve, 0-10% of a modified Y-type molecular sieve, 30-40% of amorphous silicon-aluminum and 25-35% of a binder. When the catalyst is applied to an FCC process, the yield of rich gas can be increased, and the octane number of gasoline can be improved; compared with the catalyst prepared by adopting the mechanically mixed bi-component molecular sieve, the catalyst has higher hydrothermal stability and can improve the reaction conversion rate, namely compared with the conventional catalyst containing the ZSM-5 molecular sieve, the catalyst has the functions of increasing the yield and the rich gas and improving the octane number of gasoline, and simultaneously has the function of improving the total liquid yield.

Description

A modified bicomponent molecular sieve and catalytic cracking catalyst

technical field

The invention relates to a modified two-component molecular sieve and a catalytic cracking catalyst, which is especially suitable for FCC technology, and can increase the yield of rich gas and increase the octane number of gasoline at the same time.

Background technique

Bicomponent molecular sieves belong to composite molecular sieves or porous structure molecular sieves, which are a new class of molecular sieve materials developed in recent years. Such materials mainly use special molecular sieve synthesis technology (or called skillful synthesis technology), instead of using binders, molecular sieves with different pore structures, pore size distributions and acidity are combined together (eutectic, symbiotic , cladding or connection), there may be chemical bond interactions between different structures, and there may be interconnected channels; grains of different structures may be randomly distributed, or form a core-shell structure, so as to obtain new materials with complementary properties of different types of molecular sieves, This new material has good stability.

In fact the eutectic growth of two molecular sieves is a long known phenomenon in the synthesis of molecular sieves. The essence of this phenomenon is that the medium is conducive to the development of these molecular sieves and these molecular sieves are in a metastable state. During the nucleation or growth phase, several seeds may appear and develop simultaneously, which eventually leads to the formation of mixed molecular sieves. The general development of these mixtures is based on OSWALD rules, so it can be predicted that all these systems will eventually develop into a stable state after passing through an intermediate state or a metastable state; by terminating this reaction at a certain time, the mixed molecular sieve can be isolated, these Hybrid molecular sieves have distinct morphologies that have been defined by microscopic examination. If the crystallization process can develop for a long enough time, the metastable species is transformed, and only the stable molecular sieve exists in the medium.

In addition, there is an inter-growth phenomenon in the synthesis of molecular sieves. It coordinates the growth of different types of crystals, during which molecular sieve B sporadically appears in the crystallization system of molecular sieve A. Microscopy usually fails to detect this intergrowth, an indication of the presence of zeolite B by microdiffraction studies of structural defects in zeolite A. The most famous example of this inter-growth phenomenon is that molecular sieve T is produced by the inter-growth of potassium molecular sieve and wool molecular sieve. Molecular sieves AB have different properties from purely two molecular sieves because of the perturbations in composition and pore and channel sizes caused by intergrowth.

At present, whether it is eutectic growth or inter-growth, there are no products suitable for industrial applications for naturally occurring mixed molecular sieves, and combined molecular sieves are artificially synthesized by using these two phenomena in the molecular sieve growth system and using some techniques. These novel combined molecular sieves show some promising industrial applications.

US Pat. No. 4,803,185 and US Pat. No. 4,861,739 disclose a core-shell molecular sieve with the same structure, the core of which is AlPO-11, and the shell is SAPO-11. Pellet et al. first synthesized AlPO-11 molecular sieves by distributed crystallization, then transferred the synthesized AlPO-11 molecular sieves to another crystallization system, and finally synthesized SAPO-11/AlPO-11 core-shell molecular sieves. This molecular sieve is used as an octane co-adjuvant for fluid catalytic cracking (FCC). Compared with pure SAPO-11 molecular sieve, the octane number of gasoline is higher, and the ratio of isoparaffins to normal paraffins is larger; compared with ZSM-5 Compared with gasoline, it has higher selectivity, and the ratio of isoparaffins to normal paraffins is larger.

U.S. Patent No. 4,847,224, U.S. No. 4,946,580 disclose a kind of combination type bicomponent molecular sieve, and its method is to add the nucleating gel that contains molecular sieve A seed crystal into the fresh gel that is conducive to the synthesis of molecular sieve B, in the synthesis of molecular sieve B Crystallization under the conditions to obtain a product containing two molecular sieves of AB. Molecular sieves A and B have the same structural unit, molecular sieve B is surrounded by molecular sieve A, there is a chemical bond between them, and the mechanical properties are also improved. A includes potassium molecular sieves and omega molecular sieves, and B includes omega molecular sieves and mercerized molecular sieves. They are combined with Y molecular sieves or rare earth modified Y molecular sieves for catalytic cracking. The results show that the gasoline yield can be increased and the coke yield can be decreased at the same conversion rate.

US patents US 5,888,921 and US 5,972,205 disclose a core-shell double molecular sieve with a multi-layer structure, and each layer has a different structure, acidity and composition. The design idea of this bimolecular sieve is: the shell acidity is weak (such as ALPO-5), and the inner core acidity is strong (ZSM-5). It can be used as an additive. The larger molecules in the Y-type molecular sieve product have weak cracking effect on the outer shell ALPO-5 and strong isomerization; while smaller molecules can enter the inner core and undergo short-chain isomerization at the strong acid site change. Using this double molecular sieve as an additive for fluid catalytic cracking (FCC), compared with mechanically mixing ZSM-5 and ALPO-5 molecular sieves, can increase the yield of light olefins (C ₄ , C ₅ ), and gasoline yield The loss is small.

Exxon Chemical Patents Inc. has applied for a series of patents, including WO 96-16004, WO97-45384, US 5,460,796, US 5,665,325, US 5,933,642 and other patents. In these patents, molecular sieve bonded molecular sieves are prepared by crystallizing silica-bound molecular sieve extrudates in a solution of a certain proportion of sodium hydroxide and templating agent or by spraying the silica binder in the particles (Zeolite Bound Zeolite), the second molecular sieve is symbiotic on the first molecular sieve, covering part or all of the first molecular sieve, forming a core-shell structure, which can adjust the different acidity inside and outside according to the needs. Reducing surface acidity can reduce by-products caused by non-selective catalysis of the surface. The condition for synthesizing this binderless molecular sieve is that the first and second molecular sieves are the same type of molecular sieves, or they have to match in crystal structure. It has better strength and integrity and overcomes the disadvantages of amorphous binders. It can be used in hydrocarbon conversion reactions, including cracking of naphtha, isomerization of alkylaromatics, disproportionation of toluene, transalkylation and alkylation of aromatics, reforming of naphtha to aromatics, conversion of alkanes or olefins to Oxidative conversion of aromatics and hydrocarbon products. U.S. Patent No. 5,933,642 discloses the synthesis of MFI type molecular sieves inside and outside, with a silicon-aluminum ratio of 80:1 in the inner core and 900:1 in the outer shell. Its selectivity and anti-coking ability have been improved in the disproportionation reaction.

European patent EP0,293,937 discloses a composite molecular sieve with Y-82 molecular sieve as the bottom layer of deposition and SAPO-37 as the outer layer. This combined molecular sieve is first to exchange the ammonium salt of Y-82 molecular sieve to make its Na ₂ O reach a certain range, and treat the surface of the molecular sieve with tetramethylammonium hydroxide, and then mix it with the prepared SAPO-37 molecular sieve in a certain proportion The gel is mixed and crystallized. When it is used in catalytic cracking, it has better gasoline selectivity, less gas and coke yield than pure use of Y-82 or SAPO-37 molecular sieve; especially compared with pure use of Y-82 or SAPO-37 Compared with this combined molecular sieve, molecular sieves have less aromatics content, and at the same time, due to the increase of cycloalkanes and olefins, the octane number of the final product is increased. Therefore, this molecular sieve is expected to develop a cracking and octane selective dual-functional catalyst.

The Chinese patent application 02100452.8 of the University of Petroleum (Beijing) introduces a synthesis method of a microporous composite molecular sieve. The reaction mixture gel for synthesizing the first microporous molecular sieve is prepared with the prior art, and the first-stage crystallization is carried out under certain conditions. After crystallization for a certain period of time, add a template agent (or seed crystal) for synthesizing another microporous molecular sieve, and adjust the pH of the reaction mixture to an appropriate range, and then carry out the second stage of hydrothermal treatment at a certain temperature Crystallization, after crystallization for a certain period of time, the microporous composite molecular sieve is obtained. The above-mentioned template agent (or crystal seed) of another molecular sieve can also be added before or during the crystallization of the first stage, and an external silicon-aluminum source can also be added when synthesizing the second molecular sieve.

Fluid catalytic cracking (FCC) has always been a refinery due to its strong adaptability to raw materials, high yield of light oil products, high octane number of gasoline, low device pressure level, relatively mild operating conditions, and low investment. The most important means of secondary processing. This is especially true in our country. According to statistics, 80% of gasoline in our country is produced by FCC devices. Therefore, as the core of the FCC process, the development of FCC catalysts is particularly important. It is reported that 98% of the active components of FCC catalysts are Y-type molecular sieves, mainly rare earth Y-type molecular sieves and dealuminated high-silicon ultra-stable Y-type molecular sieves, and there are also some shape-selective molecular sieves (such as ZSM-5 series, β molecular sieves, etc.). However, at present, different types of molecular sieves in the catalyst are added separately during the catalyst preparation process, and are fixed in the catalyst particles by the binder/matrix. In most cases, the different molecular sieve grains in the catalyst particles are independent of each other. Yes, the mass transfer between different molecular sieve grains (the transfer and movement of reactant/product molecules) must pass through the pores of the binder/matrix across the period. During this process, the reactions that take place are difficult to control (even some unwanted side reactions). In this case, the efficiency of realizing the synergy of shape-selective catalysis and functional catalysis among different types of molecular sieves is low. T.F.Degnan et al. reported that when ZSM-5 and Y-type molecular sieves were in the same catalyst particle, no synergy between them was found. The combined molecular sieve material is that there are two or more molecular sieves in one particle, that is, different types of molecular sieves grow eutectically or are connected to each other in a certain way in a particle, and can make the pores connect to each other. This will be beneficial to the mass transfer and synergy between molecular sieves with different pore sizes and acid distributions.

In the published publications and patent documents, there is no report on the modification of the Y/ZSM-5 combined bicomponent molecular sieve, or the preparation of a catalyst for use in the FCC process.

Contents of the invention

The object of the present invention is to provide a modified two-component molecular sieve and catalytic cracking catalyst. The cracking catalyst used in the FCC process can increase the yield of rich gas and increase the octane number of gasoline; compared with the mechanically mixed bicomponent molecular sieve, it shows higher hydrothermal stability and can increase the reaction conversion rate, that is Compared with the conventional catalyst containing ZSM-5 molecular sieve, the catalyst of the present invention not only has the function of increasing the production of rich gas and the octane number of gasoline, but also has the function of increasing the total liquid yield.

The invention introduces a modified bicomponent molecular sieve and a catalyst containing the modified bicomponent molecular sieve.

A modified two-component molecular sieve refers to a modified molecular sieve obtained by modifying a two-component molecular sieve, wherein Na ₂ O is 0.1-2.5% and RE ₂ O ₃ is 0-4% by weight percentage. ; Wherein the bicomponent molecular sieve is a microporous bicomponent molecular sieve, which is obtained by synthesizing a Y-type molecular sieve through step-by-step crystallization, and then synthesizing the mixed solution containing the Y molecular sieve into another microporous molecular sieve.

The other microporous molecular sieve is preferably ZSM-5, at this time, the X-ray diffraction peaks of the bicomponent molecular sieve include the diffraction peaks of Y and ZSM-5 molecular sieves.

The two-component molecular sieve of the present invention refers to the microporous two-component molecular sieve synthesized by using the zeolite-containing mixed liquid of synthetic faujasite through step-by-step crystallization. Obtained as described in the Chinese patent 02100452.8 applied by the University of Petroleum: Y-type molecular sieve or faujasite is first prepared in a reaction kettle, and then a template for synthesizing another microporous molecular sieve (such as ZSM-5) is added agent (or seed crystal), and adjust the pH of the reaction mixture to pH = 9.0-12.0 (preferably pH = 9.5-11.5), and then crystallize at 120-240° C. for 2-96 hours to obtain a bicomponent molecular sieve. The above-mentioned template agent (or crystal seed) of another molecular sieve can also be added before or during the crystallization of the first stage. When the second molecular sieve is synthesized, its silicon-aluminum source can be completely from the first The molecular sieve reaction mixture can also be added with an external silicon-aluminum source. The aluminum source can be aluminum sulfate, sodium aluminate, aluminum hydroxide, pseudoboehmite, etc.; the silicon source can be sodium silicate, silica sol, silica gel, white carbon black, etc.; the template agent is: ethanol, isopropanol, Primary amines (ethylamine, n-propylamine, n-butylamine, etc.) secondary amines (dipropylamine, dibutylamine, etc.) and quaternary ammonium salts (tetraethylammonium bromide, tetrapropylammonium bromide, tetrabutylammonium ammonium bromide, etc.) and their mixtures or their hydroxides (alkali); the seeds are ZSM-4, ZSM-5, ZSM-11 molecular sieve powder (the silicon-aluminum ratio is 30, 50, 500, etc., or pure silicon ZSM-5), zeolite beta powder, etc. In other words, the bicomponent molecular sieves obtained by using Chinese patent application 02100452.8 can all meet the requirements of the present invention for bicomponent molecular sieves.

The present invention does not limit the modification treatment method of bicomponent molecular sieves. After modification, Na ₂ O is 0.1-2.5%, RE ₂ O ₃ is 0-4%, especially Na ₂ O is 0.3-1.5%. %, RE ₂ O ₃ is more preferably 0 to 3%.

The general molecular sieve modification process mainly includes two treatment processes: 1), treatment with an exchange solution containing H ⁺ , NH ₄ ⁺ or RE ³⁺ ; 2), hydrothermal treatment. The two processes can be combined once or multiple times. In the present invention, the combined modification process of two exchanges and two hydrothermal treatments is preferred. The specific method can be: first treat with ^an exchange solution containing H ^{+ ,} NH ₄ ⁺ or RE ³⁺ , and then perform a hydrothermal treatment after filtration _; heat treatment.

The preferred conditions for treating with an exchange solution containing H ⁺ , NH ₄ ⁺ or RE ³⁺ in the present invention are:

H ⁺ ＝0.0001～0.01mol/L, NH ₄ ⁺ weight percent concentration is 2～15%, when performing rare earth modification, RE3+ weight percent concentration used is 0.01～1.0%, system temperature is 40～100℃, The weight ratio of the molecular sieve to the solution is 1:6-14, and the solution treatment time is 0.5-2 hours.

The anions in the exchange solution are one or more selected from Cl ^- , SO ₄ ^2- , NO ₃ ^- and CO ₃ ^2- .

The preferred hydrothermal treatment conditions of the present invention are: the water flow rate is 100-400 mL/h, the temperature is 550-650° C., and the time is 1-3 hours.

Compared with the traditional modified Y-type molecular sieve of the modified two-component molecular sieve of the present invention, the modified two-component molecular sieve

Metamolecular sieves exhibit good stability.

The invention also provides a catalyst containing the modified bicomponent molecular sieve.

A catalyst containing modified bicomponent molecular sieves, based on the weight percentage of the catalyst, the modified bicomponent molecular sieves account for 25-40%, the modified Y-type molecular sieves account for 0-10%, and the amorphous silicon-alumina accounts for 30-40%. 40%, binder accounts for 25-35%. Among them, the preferred composition is 28-36% of modified bicomponent molecular sieve, 0-8% of modified Y-type molecular sieve, 33-37% of amorphous silica-alumina, and 30-35% of binder.

The amorphous silica-alumina used in the catalyst containing the modified bicomponent molecular sieve of the present invention is preferably kaolin or modified kaolin, and the binding agent is preferably one or more of aluminum sol, acid-treated pseudo-boehmite, and silica sol Two, the modified Y-type molecular sieve is preferably REY molecular sieve.

The preparation method of the catalyst containing modified bicomponent molecular sieves of the present invention is not limited, and ordinary preparation methods can be adopted. For example, the preparation method can be after grinding molecular sieves such as modified bicomponent molecular sieves and amorphous silicon aluminum respectively. , mixed with the binder and stirred evenly, dried and calcined to obtain the catalyst.

When the catalyst containing modified bicomponent molecular sieves of the present invention is applied to the FCC process, it can increase the yield of rich gas and increase the octane number of gasoline; compared with the catalyst made of mechanically mixed bicomponent molecular sieves, the performance Higher hydrothermal stability of the catalyst.

The catalyst of the present invention can increase the rich gas production rate by 0.5 to 4 units in the FCC process where the raw material oil is Xinjiang vacuum wide fraction wax oil and Xinjiang vacuum residue, wherein the increase of propylene and isobutane accounts for the total More than 70% of the increase in rich gas; the octane number in gasoline increases by 1 to 2 units.

Description of drawings

Figure 1 is the X-ray diffraction peak diagram of the bicomponent molecular sieve used in Example 2 of the present invention, and it can be observed that the X-ray diffraction peaks include the diffraction peaks of two molecular sieves, Y and ZSM-5.

Detailed ways

Below by embodiment the present invention will be further described.

1. the raw material specification used in the embodiment, the comparative example is:

(1), NaY: industrial product, crystallinity≯90, SiO2/Al2O3≯4.8;

(2), ZSM-5: industrial product, crystallinity≯85, SiO2/Al2O3≯300;

(3), NH ₄ Cl salt: industrial product, analytically pure;

(4) Rare earth solution: industrial product, RE ₂ O ₃ =197g/l;

(5) Kaolin: Suzhou Kaolin Company;

(6) Aluminum sol: Lanzhou Catalyst Factory;

(7) Pseudo-boehmite: Shandong Pseudo-boehmite Company;

(8) Molecular sieve REY: Lanzhou Catalyst Factory;

(9) The feedstock oils used for catalyst fixed fluidized bed evaluation are Xinjiang vacuum wide distillate wax oil and Xinjiang vacuum residue. See Table 7 for properties.

2. The physical and chemical performance evaluation methods of molecular sieves and catalysts are shown in Table 6, wherein X-ray diffraction (XRD) is analyzed by D/MAX-3C X-ray diffractometer.

3. Catalyst evaluation method:

(1) Micro fixed bed reactor. Evaluation conditions: 5g of catalyst was loaded, at a reaction temperature of 460°C, 1.56g of Dagang light diesel oil (No. 0 standard diesel oil) was introduced within 70s for cracking reaction, the catalyst-to-oil ratio was 3.21, and the space velocity was 16h ^-1 .

(2) For a fixed fluidized bed, the fresh catalyst was aged at 800° C. with 100% steam for 10 hours before measurement. The raw material oil is Xinjiang vacuum wide distillate wax oil and Xinjiang vacuum residue oil, and the blending ratio of residue oil is 30% (mass percentage). The reaction temperature is 500°C, the agent/oil ratio is 3.75, the catalyst load is 150g, the oil feed is 40g, and the space velocity is 16h ^-1 .

Example 1

The directing agent is prepared by the method for preparing NaY directing agent proposed in US Pat. No. 3,639,009, and the specific formula is as follows: 15SiO ₂ :Al ₂ O ₃ :16Na ₂ O:320H ₂ O (molar ratio).

First prepare the two-component molecular sieve: (wt% refers to weight percentage, the same below)

17.30 grams of water glass are diluted with 13.46 grams of deionized water, then add 1.31 grams of 50wt% aluminum sulfate octadecadecanoate hydrate solution successively under stirring, 3.89 grams of guiding agent, low-alkali sodium aluminate (solution (Al ₂ O ₃ is 16.2wt%, _Na2O is 12.3wt%) 5.25 grams and 3.77 grams of 3 mol/litre sulfuric acid solution is made into gel, after stirring for 30 minutes, gel is put into 100 milliliters of reaction kettles lined with polytetrafluoroethylene Crystallize at 100°C for 24 hours, after cooling, add 0.68 grams of tetraethylammonium bromide and 1.06 grams of tetrapropylammonium bromide, stir for 10 minutes, then adjust the pH value of the mixed slurry with 6.20 grams of 3 mol/liter sulfuric acid solution , stirred for 30 minutes, covered the reactor and crystallized at 140°C for 40 hours. After the reaction, the product was filtered, washed, and dried to obtain a combined bicomponent molecular sieve A. This bicomponent molecular sieve A was identified by XRD to have ZSM- 5 characteristic peaks and NaY characteristic peaks, no P-type miscellaneous crystals.

Take 100 grams (dry basis) of molecular sieve A and pour it into an exchange tank equipped with 800 ml of exchange solution (containing 8.05 wt% of NH ₄ Cl salt), exchange at 90°C for 1 hour, and control the pH of the solution during the exchange process = 3.3～ 3.7, after exchange, filter and wash; after roasting at 600°C for 2h, pour the roasted product into an exchange tank filled with 800ml of exchange solution (containing 5.88wt% NH ₄ Cl salt), exchange at 90°C for 1h, and During the exchange process, the pH of the solution was controlled to be 3.3-3.7. After the exchange, it was filtered, washed, and calcined at 600° C. for 2 hours to obtain the modified bicomponent molecular sieve A1 of the present invention. The physical properties of molecular sieve A1 are shown in Table 1.

Comparative example 1

According to the ratio of NaY and ZSM-5 in molecular sieve A in Example 1, weigh a total of 100g (dry basis) of NaY, ZSM-5 molecular sieve and amorphous silica-alumina material and make it mechanically mix to obtain molecular sieve B.

The molecular sieve B was treated by the modification method in Example 1 to obtain a modified molecular sieve B1.

Table 1 has listed the physical and chemical properties of modified molecular sieve A1, B1, and through 800 ℃, 100% water vapor, 4 hours aging before and after, the change of (5,5,5) peak height in molecular sieve X-ray diffraction pattern, can therefrom It can be seen that the crystallinity retention rate of the combined bicomponent molecular sieve is high (that is, the stability is good).

Table 1 Comparison of physical and chemical properties between modified molecular sieve A1 and modified molecular sieve B1 project Example 1 Comparative example 1 A1 B1 (5,5,5) peak height, mm 82 76 (5,5,5) peak height (800℃, 100% water vapor, 4h), mm 50 38 Crystallinity retention rate, % 60.98 50.00 Na ₂ O m% 0.48 0.48

Example 2

The preparation of the directing agent is the same as in Example 1.

15.81 grams of water glass are diluted with 13.94 grams of deionized water, then add 1.31 grams of 50wt% aluminum sulfate octadecadecanoate hydrate solution successively under stirring, 4.32 grams of guiding agent, low-alkali sodium metaaluminate solution (Al ₂ O ₃ is 16.2wt%, _Na2O is 12.3wt%) 6.30 grams and 3.79 grams of 3 mol/litre sulfuric acid solution is made into gel, after stirring for 30 minutes, gel is put into 100 milliliters of reaction kettles lined with polytetrafluoroethylene Crystallize at 100°C for 24 hours, after cooling, add ZSM-5 seed crystals according to 1wt% of the dry basis, stir for 20 minutes, then adjust the pH value of the mixed slurry with 6.25 grams of 3 mol/liter sulfuric acid solution, stir for 30 minutes and cover The upper reactor was crystallized at 160°C for 24 hours. After the reaction, the product was filtered, washed, and dried to obtain a combined bicomponent molecular sieve A'. This bicomponent molecular sieve A' is identified by XRD to have ZSM-5 characteristic peaks and NaY characteristic peaks, as shown in FIG. 1 .

Get 100 grams (dry basis) of the molecular sieve A' prepared in Example 1 and pour it into an exchange tank containing 1100 milliliters of exchange solution (containing 4.31wt% NH ₄ Cl salt and 0.19wt% RE ₂ O ₃ ), Exchange at 90°C for 1 hour, and control the pH of the solution to 3.3 to 3.7 during the exchange process. After the exchange, filter, wash, and roast at 600°C for 2 hours, pour the roasted product into a container containing 1100 milliliters of exchange solution (containing 3.33 wt % In the exchange tank of NH ₄ Cl salt and 5.0wt% (NH ₄ ) ₂ SO ₄ salt), exchange at 90°C for 1h, and control the pH of the solution during the exchange process=3.3～3.7, filter after exchange, wash, and wash at 600 The modified bicomponent molecular sieve A2 of the present invention was obtained by calcining for 2 hours at ℃. The physical properties of molecular sieve A2 are shown in Table 2, RE ₂ O ₃ is 1.29m%.

Comparative example 2

Take 100 grams (dry basis) of industrial NaY molecular sieves, and process them according to the modification method of molecular sieves described in Example 2 to obtain modified molecular sieves C1.

Comparative example 3

According to the ratio of NaY and ZSM-5 in molecular sieve A in Example 1, a total amount of 100 g (dry basis) of NaY and ZSM-5 molecular sieves was weighed and mechanically mixed to obtain molecular sieve D. According to the modification method of the molecular sieve described in Example 2, the modified molecular sieve D1 was obtained.

Table 2 lists the properties of modified molecular sieves A2, C1, and D1 and the crystallinity retention data before and after modification of different molecular sieves, which can also reflect the good stability of the combined bicomponent molecular sieve, and the Na in the molecular sieve is easily exchange.

Table 2 Comparison of physical and chemical properties of different modified molecular sieves project Example 2 Comparative example 2 Comparative example 3 A2 C1 D1 Crystallinity Retention % 63.60 60.87 61.17 Na ₂ O m% 0.37 0.66 0.45

Example 3

The catalyst was prepared by using 35 g of the modified molecular sieve A1 (dry basis) obtained in Example 1. Based on the weight percentage of the catalyst (the same below), molecular sieve A1 accounts for 35%, kaolin accounts for 50%, and aluminum sol accounts for 15%. Its preparation method is to grind molecular sieve and kaolin separately, mix with aluminum sol and make it evenly stirred, dry at 120°C, and then roast at 600°C for 2 hours to make small particles of 20-40 meshes, which is the present invention. Catalyst H1. Catalysts were evaluated in a micro fixed bed reactor. Table 3 lists the activity changes of catalyst H1 after aging at 800°C, 100% water vapor, and different time.

Example 4

The catalyst was prepared by using 1000 g of the modified molecular sieve A2 (dry basis) obtained in Example 2. The proportion of molecular sieve A2 in the catalyst is 35%, and in addition, there are 35% of kaolin, 20% of acidified pseudo-boehmite and 10% of alumina sol binder in the catalyst. Its preparation method is first to fully mix kaolin and pseudo-boehmite evenly, and after acidification treatment, then fully mix with molecular sieve and binder, and finally make 40-130 mesh particles by spraying and drying to obtain the present invention. Catalyst H2. The catalysts were evaluated using a fixed fluidized bed. Table 4 lists the selectivity of catalyst H2.

Example 5

Using 1000 g of modified molecular sieve A2 (dry basis) prepared in Example 2 to compound with high-activity molecular sieve REY (the compounding ratio is 5: 1), the proportion of compounded molecular sieve in the catalyst is 35%, All the other compositions are the same as in Example 4. The catalyst was prepared by the method of Example 4, that is, the catalyst H3 of the present invention was prepared. The catalysts were evaluated using a fixed fluidized bed.

Table 5 lists the selectivity of the catalyst H3 and the (5,3,3) peak retention rate in the X-ray diffraction diagram before and after the catalyst is aged at 800°C, 100% water vapor, and 10 hours.

Comparative example 4

The modified molecular sieve B1 obtained in Comparative Example 1 was used instead of the modified molecular sieve A1, and catalyst K1 was prepared according to the composition and method of Example 3. Catalysts were evaluated in a micro fixed bed reactor. Table 3 lists the activity changes of catalysts H1 and K1 after aging at 800°C in 100% water vapor for 4 hours and 10 hours.

Table 3 The change of micro-reaction activity of the catalyst after aging for different times project Example 3 Comparative example 4 H1 K1 Slight reaction activity (800°C, 100% water vapor, 4 hours), % 65 63 Slight reaction activity (800°C, 100% water vapor, 10 hours), % 60 55

Comparative example 5

The modified molecular sieve C1 obtained in Comparative Example 2 was used instead of the modified molecular sieve A2, and catalyst K2 was prepared according to the composition and method of Example 4. Catalyst selectivity evaluation was carried out using a fixed fluidized bed. Table 4 compares the selectivity of catalysts H2 and K2.

The selectivity comparison of different catalysts of table 4 project Example 4 Comparative example 5 H2 K2 dry gas m% 1.82 1.66 Rich gas m% 21.34 18.49 Rich gas composition Propylene m% 5.89 4.98 Isobutane m% 6.77 5.68 other m% 8.68 7.83 Gasoline m% 50.24 51.43 Diesel m% 15.14 15.54 Heavy oil m% 5.10 5.21 coke m% 5.83 5.75 conversion m% 79.23 77.33 properties of gasoline NP 3.69 3.79 IP 33.96 32.52 o 26.10 24.32 N 9.22 8.18 A 27.03 31.18 RON 93.2 91.2

It can be seen from Table 4 that the use of the catalyst H2 containing the modified bicomponent molecular sieve A2 of the present invention can increase the octane number of gasoline by 1 to 2 units, and at the same time the yield of rich gas has increased significantly, of which propylene and iso The increase of butane accounted for more than 70% of the total increase of rich gas.

Comparative example 6

The modified molecular sieve D1 prepared in Comparative Example 3 was used to replace the modified molecular sieve A2, and catalyst K3 was prepared according to the composition and method of Example 5. The catalysts were evaluated using a fixed fluidized bed.

Table 5 compares the selectivity of catalysts H3 and K3 and the (5,3,3) peak retention in the X-ray diffraction diagram before and after the catalysts were aged at 800° C. in 100% water vapor for 10 hours.

The selectivity comparison of different catalysts of table 5 project Example 5 Comparative example 6 H3 K3 (5,3,3) peak retention rate (8000C, 100% water vapor 10h) mm 54 40 dry gas m% 2.27 2.32 Rich gas m% 17.69 17.28 Gasoline m% 46.41 41.38 Diesel m% 18.27 19.46 Heavy oil m% 7.10 11.51 coke m% 7.18 7.34 Total liquid recovery m% 82.37 78.12 conversion m% 73.55 68.32 properties of gasoline NP 4.47 4.56 IP 38.27 32.74 o 17.03 18.62 N 8.10 7.47 A 32.13 36.22 MON 82.7 82.7 RON 95.6 95.5

From the evaluation results in Table 5, it can be seen that compared with the catalyst prepared by mechanically mixing molecular sieves, the catalyst containing bicomponent molecular sieves has no significant difference in the gas-rich yield and octane number, but the total liquid yield is greatly increased, and heavy oil The conversion rate increases, this result is related to the higher stability of the composite molecular sieve, thereby improving the reaction conversion rate of the catalyst, which can also be seen from the (5,3,3) peak heights in the X-ray diffraction diagrams after the water vapor treatment of the two The retention rate is demonstrated.

Table 6 The main analysis and evaluation methods involved in the present invention project method Standard Y molecular sieve crystallinity X-ray Diffraction Q/SH018·0172-93 Na ₂ O flame photometry Q/SH018·0144-91 RE ₂ O ₃ Colorimetry Q/SH018·0175-93 Catalyst activity microreactor method Q/SH0180846 Catalyst selectivity small fixed fluidized bed method Q/SH018·0516-91 gasoline octane number Chromatography Q/SH018·0133-90

Table 7 Properties of feedstock oil used in catalyst selectivity evaluation project Xinjiang vacuum wide distillate wax oil Xinjiang vacuum residue Carbon residue m% 0.285 9.76 Elemental analysis N m% 0.054 0.57 C m% 86.82 86.71 Hm% 13.16 12.17 Heavy Metal Analysis Cuμg/g 0.14 0.87 Pbμg/g 0.15 0.89 Feμg/g 8.90 21.55 Niμg/g 0.58 26.64 Vμg/g 0.22 4.67 family composition analysis Saturated hydrocarbon m% 86.7 45.7 Aromatics m% 12.8 47.3 Colloid m% 0.5 5.7 molecular weight 323 882

Claims (14)

1. A modified two-component molecular sieve, which refers to a modified two-component molecular sieve obtained by modification treatment, in which _Na2O is 0.1-2.5% and _RE2O3 is 0-4% _. Molecular sieve; wherein the bicomponent molecular sieve is a microporous bicomponent molecular sieve, through step-by-step crystallization, the Y-type molecular sieve is first synthesized, and then the template agent or seed crystal for synthesizing ZSM-5 is added to the mixed solution containing the Y molecular sieve, and It is obtained by adjusting the pH of the reaction mixture and recrystallization; the silicon source and aluminum source for the synthesis of ZSM-5 are completely from the reaction mixture of the first molecular sieve, or additional silicon source and aluminum source are added. 2. The modified two-component molecular sieve according to claim 1, wherein the two-component molecular sieve is prepared by first preparing a Y-type molecular sieve in a reaction kettle, and then adding a template or a seed crystal for synthesizing ZSM-5, It is obtained by adjusting the pH of the reaction mixture to a pH of 9.0-12.0, and then heating up and crystallizing at 120-240° C. for 2-96 hours. 3. The modified bicomponent molecular sieve according to claim 2, characterized in that the bicomponent molecular sieve is obtained by first adding the required silicon source, aluminum source and guiding agent for the synthesis of the Y-type molecular sieve in a reaction kettle, after mixing uniformly Crystallize at 90-120°C for 10-48 hours to obtain a Y-type molecular sieve with high crystallinity; then add the template agent or seed crystal of ZSM-5, and adjust the pH of the reaction mixture to pH=9.0-12.0 with phosphoric acid, and then Obtained by heating and crystallizing at 120-240°C for 2-96 hours. 4. The modified bicomponent molecular sieve according to claim 1, characterized in that the bicomponent molecular sieve is obtained by first adding the required silicon source, aluminum source and guiding agent for the synthesis of a Y-type molecular sieve in a reaction kettle, after mixing uniformly Crystallize at 90-120°C for 10-48 hours to obtain Y-type molecular sieve with high crystallinity; then recrystallize to synthesize ZSM-5; and the template or seed crystal of ZSM-5 is before the first stage of crystallization or added during crystallization. 5. The modified bicomponent molecular sieve according to claim 1, characterized in that the silicon source of the bicomponent molecular sieve is one or more of sodium silicate, silica sol, silica gel, and white carbon black. 6. The modified bicomponent molecular sieve according to claim 1, characterized in that the aluminum source of the bicomponent molecular sieve is one or more of aluminum sulfate, sodium aluminate, aluminum hydroxide, and pseudoboehmite. 7. The modified bicomponent molecular sieve according to claim 1, characterized in that the template used for the bicomponent molecular sieve is: ethanol, isopropanol, primary amine, secondary amine and quaternary ammonium salt and mixture thereof or their of hydroxide. 8. The modified bicomponent molecular sieve according to any one of claims 1 to 7, wherein the modification treatment of the bicomponent molecular sieve refers to a combined modification process using two exchanges and two hydrothermal treatments: It is firstly treated with an exchange solution containing H ⁺ , NH ₄ ⁺ or RE ³⁺ , filtered, and subjected to a hydrothermal treatment, then treated with an exchange solution containing H ⁺ , NH ⁴⁺ , and then subjected to a hydrothermal treatment. 9. The modified bicomponent molecular sieve according to claim 8, characterized in that the modification process of the bicomponent molecular sieve through two exchanges and two hydrothermal treatments is: (1). Treat bicomponent molecular sieves with an exchange solution containing H ⁺ , NH ₄ ⁺ or RE ³⁺ , the system temperature is 40-100°C, and the solution treatment time is 0.5-2 hours; (2) Carry out hydrothermal treatment, temperature 550～650 ℃, time 1～3 hours; (3) Treat with an exchange solution containing H ⁺ and _NH4 ⁺ , the system temperature is 40-100°C, and the solution treatment time is 0.5-2 hours; (4) Carry out a hydrothermal treatment again, and its processing condition is the same as the condition of (2) of the hydrothermal treatment for the first time. 10. A catalytic cracking catalyst comprising the modified bicomponent molecular sieve according to claim 1, characterized in that based on the weight percentage of the catalyst, the modified bicomponent molecular sieve accounts for 25-40%, and the modified Y-type Molecular sieves account for 0-10%, amorphous silica-alumina accounts for 30-40%, and binder accounts for 25-35%. 11. The catalytic cracking catalyst according to claim 10, characterized in that based on the weight percentage of the catalyst, the modified bicomponent molecular sieve accounts for 28-36%, the modified Y-type molecular sieve accounts for 0-8%, and the amorphous silicon Aluminum accounts for 33-37%, and binder accounts for 30-35%. 12. The catalytic cracking catalyst according to claim 10 or 11, characterized in that the amorphous silica-alumina is kaolin or modified kaolin. 13. The catalytic cracking catalyst according to claim 10 or 11, characterized in that the binder is one or both of alumina sol, acid-treated pseudo-boehmite, and silica sol. 14. The catalytic cracking catalyst according to claim 10 or 11, characterized in that the modified Y-type molecular sieve is REY molecular sieve.