A high-strength low-carbon olefin aid

Abstract

The application discloses a high-strength low-carbon olefin aid, which comprises IMF structure molecular sieves and MFI molecular sieves, zirconium sol, phosphorus aluminum binder and metal additives; the IMF structure molecular sieves and the MFI molecular sieves account for 10-75% of the dry base weight of the aid; the zirconium sol accounts for 1-20% of the zirconium oxide; the phosphorus aluminum binder accounts for 3-35% of the weight; and the metal additives account for 0.5-10%. The aid can improve the concentration of propylene and butene in catalytic cracking liquefied gas and the concentration of ethylene in dry gas.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysts, and particularly relates to a high-strength low-carbon olefin catalyst additive. BACKGROUND

[0002] Under the FCC reaction conditions, the acidity and the shape-selective effect of the pores of the catalyst determine the yield of low-carbon olefins in the products. The unique pore structure and acidity of the zeolite with a five-membered ring structure make it have good catalytic performance in the deep processing of low-carbon olefins. In order to increase the production of light olefins and propylene, it is an effective technical approach to use a catalyst or additive containing ZSM-5 molecular sieve. However, the biggest weakness of this ZSM-5 molecular sieve is poor activity stability, which is easy to be deactivated under the harsh periodic regeneration conditions of the FCC device.

[0003] CN100389174C discloses a cracking additive for increasing the concentration of propylene, which is composed of 10-65 wt% of modified ZSM-5 molecular sieve, 0-60 wt% of clay, 15-60 wt% of inorganic oxide binder, 0.5-15 wt% of metal additive selected from one or more of the metals in Group VIIIB, and 2-25 wt% of phosphorus additive, wherein the modified ZSM-5 molecular sieve is modified by phosphorus and one of Fe, Co or Ni, and its anhydrous chemical formula, in terms of oxides, is (0-0.3)Na2O·(0.5-5)Al2O3·(1.3-10)P2O5·(0.7-15)MxOy·(70-97)SiO2, x represents the atomic number of M, and y represents a number required to meet the oxidation state of M, and the metal additive and the phosphorus additive are both in terms of oxides. The cracking additive is applied to the catalytic cracking process of petroleum hydrocarbons, and can significantly increase the concentration of propylene in the liquefied gas while increasing the yield of catalytic cracking liquefied gas and improving the octane number of catalytic cracking gasoline.

[0004] IM-5 molecular sieve is an IMF structure molecular sieve, which was first synthesized by Benazzi in 1998. The structural analysis work was completed by Baerlocher et al. in 2007. The molecular sieve has a two-dimensional ten-membered ring pore structure, and its pore diameter is similar to that of ZSM-5 molecular sieve, and there is a limited pore in the third dimension. Since it has a similar pore structure to ZSM-5 molecular sieve, and has higher acid amount and better hydrothermal stability, it has characteristics in many catalytic reactions. Corma et al. conducted a series of studies on the catalytic performance of IM-5 molecular sieve, and found that it has higher cracking ability for alkanes than ZSM-5 molecular sieve. Studies have shown that IM-5 molecular sieve can significantly increase the selectivity of butene in LPG and reduce coke in catalytic cracking reactions.

[0005] In order to protect the molecular sieve while improving the selectivity of low carbon olefins, the substrate is often modified. Therefore, the present application adopts two structures of molecular sieve, matches the substrate and catalyst modification technology, and provides a catalytic cracking aid for increasing the concentration of low carbon olefins, improving the concentration of low carbon olefins in liquefied gas, and improving the concentration of ethylene in dry gas. SUMMARY

[0006] In order to improve the selectivity and yield of low carbon olefins in catalytic cracking products, the present application provides a high-strength low carbon olefin aid.

[0007] The present application provides a high-strength low carbon olefin aid, which comprises 10-75 wt% of IMF structure molecular sieve and MFI molecular sieve based on dry weight, 1-20 wt% of zirconium sol based on dry weight, 3-35 wt% of phosphorus aluminum binder based on dry weight, 0.5-10 wt% of metal additive selected from at least one of Group VIII metals or manganese, zinc, gallium based on dry weight, 1-20 wt% of other inorganic binder based on dry weight, and 0-60 wt% of second clay based on dry weight.

[0008] According to an embodiment of the present application, the mass ratio of the IMF structure molecular sieve and the MFI molecular sieve is 0.01-100, preferably 0.1-30, further preferably 0.25-4.5, and more preferably 0.5-4.5.

[0009] According to an embodiment of the present application, the IMF structure molecular sieve is one or more selected from hydrogen type IM-5, phosphorus-containing IM-5 and phosphorus and transition metal-containing IM-5 molecular sieve; and the MFI molecular sieve is one or more selected from hydrogen type MFI molecular sieve, phosphorus-containing MFI molecular sieve, phosphorus and transition metal-containing MFI molecular sieve.

[0010] According to an embodiment of the present application, the metal additive is a metal compound; preferably, the metal compound is at least one selected from oxides, hydroxides, chlorides, nitrates, sulfates, phosphates and organic compounds; more preferably, the metal compound is one or more selected from oxides, orthophosphates, phosphites, basic phosphates and acid phosphates; and further preferably, the metal is one or more of Fe, Zn and Cu.

[0011] According to an embodiment of the present application, the phosphorus aluminum binder is a first clay-containing phosphorus aluminum inorganic binder.

[0012] According to an embodiment of the present application, the preparation steps of the first clay-containing phosphorus aluminum inorganic binder include:

[0013] (1) dispersing an alumina source, a first clay and water into a slurry with a solid content of 8-45% by weight; the alumina source is aluminum hydroxide and / or alumina which can be peptized by acid, and the weight ratio of the first clay to the alumina source in terms of Al2O3 is (greater than 0-40):(15-40) on a dry basis;

[0014] (2) adding concentrated phosphoric acid into the slurry obtained in step (1) in a weight ratio of P / Al=1-6 under stirring;

[0015] (3) reacting the slurry obtained in step (2) at a temperature of 50-99°C for 15-90 minutes.

[0016] According to an embodiment of the present application, the first clay is selected from at least one of kaolin, sepiolite, attapulgite, rectorite, montmorillonite and diatomite; preferably, the first clay is kaolin.

[0017] According to an embodiment of the present application, the second clay is selected from at least one of kaolin, sepiolite, attapulgite, rectorite, montmorillonite and diatomite; and / or

[0018] The other inorganic binder is at least one selected from pseudoboehmite, acidified alumina, aluminum sol, silica-aluminum sol and water glass.

[0019] According to an embodiment of the present application, the zirconium sol is prepared by hydrolysis of a zirconium salt, and the preparation method is selected from one or more of alkali addition method, oxidation method and ion exchange method, preferably alkali addition method.

[0020] According to an embodiment of the present application, the preparation method of the zirconium sol is:

[0021] (1) preparing a solution of a zirconium source at room temperature to a certain concentration, and stirring uniformly; the concentration of ZrO2 is 0.5-20% by weight in terms of oxide;

[0022] (2) adding a stabilizer into the above solution in a molar ratio of 1-6 times of zirconium, and stirring at room temperature to 90°C for 0.5-3 hours to make it fully react, to obtain a first mixed solution;

[0023] (3) slowly adding a lye into the above solution at room temperature to 50°C by a pump, and controlling the amount of the lye to make the pH of the zirconium sol be 0-10, preferably 1-7, and more preferably 2-5, to obtain a clear and transparent zirconium sol.

[0024] According to an embodiment of the present application, the stabilizer is an organic acid selected from at least one of acetic acid, glycolic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, citric acid and the like, preferably acetic acid or citric acid.

[0025] The application provides a preparation method of the above-mentioned additive, characterized by comprising the following steps:

[0026] (1) mixing the IMF structure molecular sieve, the MFI molecular sieve, the zirconium sol, the inorganic binder and the second clay slurry, beating the slurry, introducing a metal additive, and finally adding a phosphorus aluminum binder and spray drying;

[0027] (2) drying and calcining.

[0028] According to an embodiment of the application, the drying temperature is room temperature to 400 DEG C, preferably 100-300 DEG C, the calcining temperature is 400-700 DEG C, and the calcining time is 0.5-100 hours, preferably 0.5-10 hours.

[0029] The application provides a catalytic cracking catalyst comprising the above-mentioned additive or the additive prepared according to the above-mentioned preparation method.

[0030] The application provides a catalytic cracking method, comprising the step of contacting and reacting a hydrocarbon oil with a mixture of the above-mentioned catalytic cracking catalyst.

[0031] Advantages:

[0032] The application adopts the IMF structure molecular sieve and the MFI molecular sieve, so that the yield and selectivity of propylene and butylene in liquefied gas can be improved. The catalytic additive provided by the application can effectively increase the yield of catalytic cracking low-carbon olefins, significantly improve the ethylene concentration in dry gas and the propylene and butylene in liquefied gas, and improve the wear strength by adopting the zirconium sol. DETAILED DESCRIPTION

[0033] The detailed description of the specific embodiments of the present disclosure is described below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and are not used to limit the present disclosure.

[0034] The preparation method of the catalytic cracking additive provided by the application mixes the IMF structure molecular sieve and the MFI molecular sieve, the zirconium sol and other inorganic binders and clay and molecular sieve slurry, and beats the slurry. The feeding sequence is not particularly required, preferably, the clay and the molecular sieve slurry are mixed first, then the zirconium sol and other inorganic binders are mixed and beaten, and finally the phosphorus aluminum binder is added, which is beneficial to improve the activity and strength of the additive.

[0035] The catalytic cracking aid provided by the present disclosure is suitable for catalytic cracking of various hydrocarbon oils. When used in a catalytic cracking process, the catalytic cracking aid can be added to a catalytic cracking reactor alone or mixed with a catalytic cracking catalyst. Generally, the amount of the catalytic cracking aid provided by the present disclosure in the mixture of the FCC catalyst and the catalytic cracking aid provided by the present disclosure is not more than 30% by weight, preferably 1-25% by weight, more preferably 3-15% by weight, and the hydrocarbon oil is selected from one or more of various petroleum fractions, such as crude oil, atmospheric residue, vacuum residue, atmospheric wax oil, vacuum wax oil, straight-run wax oil, propane light / heavy deoiled, coking wax oil, and coal liquefaction products.

[0036] The catalytic cracking aid provided by the present disclosure is used in a catalytic cracking process, and the catalytic cracking conditions of the hydrocarbon oil can be conventional catalytic cracking conditions. Generally, the catalytic cracking conditions of the hydrocarbon oil include a reaction temperature of 400-600°C, preferably 450-550°C, a weight hourly space velocity of 8-120 h-1, preferably 8-80 h-1, and a catalyst to oil ratio (weight ratio) of 1-20, preferably 3-15. The catalytic cracking aid provided by the present disclosure can be used in various existing catalytic cracking reactors, such as in fixed bed reactors, fluidized bed reactors, riser reactors, multi-reaction zone reactors, etc.

[0037] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited in any way by the examples. The instruments and reagents used in the examples of the present disclosure are conventional instruments and reagents used by those skilled in the art, unless otherwise specified.

[0038] When the aid of the present disclosure is used for performance evaluation of catalytic cracking reactions, the ACE device is used for evaluation.

[0039] The RIPP standard method described in the present disclosure can be found in "Analysis Methods for Petroleum and Chemical Industry", Yang Cuiding et al., 1990 edition.

[0040] The determination of attrition index (straight tube method) is mainly to put a certain amount of sample into an attrition index determination device, and blow for five hours at a constant gas velocity. The sample blown out in the first hour is discarded, and the sample blown out in the last four hours is collected to calculate the average attrition percentage per hour (the weight of the sample less than 15 microns blown out per hour accounts for the percentage of the weight of the catalyst greater than 15 microns), which is called the attrition index of the catalyst, and its unit is % / h. The smaller the attrition index, the better the anti-wear performance of the catalyst. Hot attrition is the percentage content of the catalyst loss under the conditions of 700 degrees Celsius, a gas velocity of 10 L / min, and an attrition time of 5h.

[0041] The properties of some of the raw materials used in the examples are as follows:

[0042] Pseudo-boehmite is an industrial product produced by Shandong Aluminum Industry Co., Ltd., with a solid content of 60% by weight;

[0043] Alumina sol is an industrial product produced by SINOPEC Qilu Catalyst Branch, with Al203 content of 21.5 wt.%;

[0044] Kaolin is a special kaolin for catalytic cracking catalyst produced by Suzhou Kaolin Company, with solid content of 78 wt.%.

[0045] Hydrochloric acid: chemical purity, concentration of 36-38 wt.%, produced by Beijing Chemical Plant.

[0046] ZSP-4: an industrial product produced by SINOPEC Qilu Catalyst Branch, with P2O5 content of 4.25%, Fe2O3 content of 1.85%, and crystallinity of 76%.

[0047] P-IM-5: H-IM-5 molecular sieve is impregnated with saturated ammonium dihydrogen phosphate solution with a concentration of 0.2 mol / L, stirred for two hours, dried at 120°C for 10 hours, and calcined at 500°C for 3 hours to obtain phosphorus-modified IM-5 molecular sieve P-IM-5, with P2O5 content of 4.23 mass%, and crystallinity of 78%.

[0048] Examples 1-3 are zirconium sol preparation examples

[0049] Zirconium sol preparation example 1:

[0050] Into a beaker, 130 g of deionized water was added, then 125 g of zirconium oxychloride was added, stirred for 10 min, 50 g of acetic acid was slowly added, stirred for 30 min to obtain a mixed solution; then concentrated ammonia was slowly added to the above solution by pump, the pump speed was controlled at 1.5 times / min, and the PH was controlled at 2.5 to obtain a clear and transparent zirconium sol ZM-1.

[0051] Zirconium sol preparation example 2

[0052] Into a beaker, 130 g of deionized water was added, then 125 g of zirconium oxychloride was added, stirred for 10 min, 38 g of oxalic acid was slowly added, stirred for 30 min to obtain a mixed solution; then concentrated ammonia was slowly added to the above solution by pump, the pump speed was controlled at 1.5 times / min, and the PH was controlled at 2.5 to obtain a clear and transparent zirconium sol ZM-2.

[0053] Zirconium sol preparation example 3

[0054] Into a beaker, 170 g of deionized water was added, then 176 g of zirconium isopropoxide was added, stirred for 10 min, 38 g of oxalic acid was slowly added, stirred for 30 min to obtain a mixed solution; then triethanolamine was slowly added to the above solution by pump, the pump speed was controlled at 1.5 times / min, and the PH was controlled at 2.5 to obtain a clear and transparent zirconium sol ZM-3.

[0055] Example 4

[0056] This example prepares a phosphorus-aluminum inorganic binder described in the present disclosure.

[0057] 1.91 kg of pseudo-boehmite (containing 1.19 kg of Al2O3), 0.56 kg of kaolin (dry basis 0.50 kg) and 3.27 kg of deionized water were slurried for 30 minutes, and 5.37 kg of concentrated phosphoric acid (mass concentration 85%) was added to the slurry under stirring at a rate of 0.04 kg of phosphoric acid per minute per kg of alumina source, and the temperature was raised to 70°C, and then reacted at this temperature for 45 minutes to obtain the phosphorus-aluminum binder.

[0058] Catalyst Example 1:

[0059] (1) Molecular sieve P-IM-5 and ZSP-4 molecular sieve were taken and slurried for 10 min with deionized water, and then slurried for 120 min to obtain a molecular sieve slurry; kaolin, aluminum sol and zirconium sol, and aluminum stone were taken and slurried for 20 min with deionized water, and then the molecular sieve slurry was added under stirring, and an aqueous solution of FeCl3·6H2O (FeCl3 content 30 wt%) was added under stirring, and then the slurry was continued for 45 min, and finally the phosphorus-aluminum binder was added, and stirred for 5 min, and the obtained slurry was spray dried to obtain microspheres.

[0060] CAT-1 was prepared by calcining at 500°C for 2 hours, and the specific ratio is shown in Table 2.

[0061] Examples 2-5: The same steps as in Example 1, and the specific ratio is shown in Table 2.

[0062] Comparative Example 1:

[0063] Molecular sieve ZSP-4 molecular sieve, kaolin and aluminum stone were taken and slurried for 120 min with deionized water and aluminum sol, and then the slurry was continued for 45 min, and then the phosphorus-aluminum inorganic binder was added, and stirred for 5 min, and the obtained slurry was spray dried to obtain microspheres, and the microspheres were calcined at 500°C for 1 hour to obtain DCAT-1, and the specific ratio is shown in Table 1.

[0064] Table 1

[0065]

[0066] The catalysts containing zirconium sol have a significantly reduced attrition index and a significantly improved strength.

[0067] The following examples use a fixed fluidized bed reactor to illustrate the cracking reaction effect of the cracking aids provided by the present disclosure.

[0068] The FCC catalyst SLA and 30 g of CAT-1 to 5 and DCAT 1 to 4 were aged at 800°C under 100% steam atmosphere for 17 hours, respectively. Different amounts of the aged catalysts were mixed with SLA (the main properties of which are shown in Table 3), and the catalyst mixtures were charged into a reactor of a small fixed fluidized bed reaction device to perform catalytic cracking of the feedstock oils shown in Table 4. The reaction conditions and the reaction results are shown in Table 5.

[0069] Table 2 Main properties of SLA

[0070]

[0071] Table 3 Properties of the feedstock oils for evaluation

[0072]

[0073]

[0074] Table 4 Evaluation results

[0075]

[0076]

[0077] As can be seen from Table 4, the catalytic aid provided by the present application can effectively increase the yield of catalytic cracking liquefied gas, and significantly increase the propylene and butene in the catalytic cracking liquefied gas and the ethylene concentration in dry gas, as compared with the reference aid.

Claims

1. A high-strength low-carbon olefin aid characterized in that, The additive comprises 10-75 wt% of IMF structure molecular sieve and MFI molecular sieve based on dry base weight, 1-20 wt% of zirconium sol based on dry base weight, 3-35 wt% of phosphorus aluminum binder based on dry base weight, 0.5-10 wt% of metal additive selected from at least one of Group VIII metal or manganese, zinc, gallium based on dry base weight, 1-20 wt% of other inorganic binder based on dry base weight, and 0-60 wt% of second clay based on dry base weight; The mass ratio of the IMF structure molecular sieve and the MFI molecular sieve is 0.01-100; The IMF structure molecular sieve is one or more selected from hydrogen type IM-5, phosphorus-containing IM-5 and phosphorus and transition metal-containing IM-5 molecular sieve; and the MFI molecular sieve is one or more selected from hydrogen type MFI molecular sieve, phosphorus-containing MFI molecular sieve, phosphorus and transition metal-containing MFI molecular sieve. The zirconium sol is prepared by hydrolysis of zirconium salt, and the preparation method is one or more selected from alkali addition method, oxidation method and ion exchange method.

2. The adjuvant according to claim 1, characterized in that, The mass ratio of the IMF structure molecular sieve and the MFI molecular sieve is 0.1-30.

3. The adjuvant according to claim 2, characterized in that, The mass ratio of the IMF structure molecular sieve and the MFI molecular sieve is 0.25-4.

5.

4. The adjuvant according to claim 3, characterized in that, The mass ratio of the IMF structure molecular sieve and the MFI molecular sieve is 0.5-4.

5.

5. The adjuvant of claim 1, wherein, The metal additive is a metal compound.

6. The adjuvant of claim 5, wherein, The metal compound is at least one selected from oxide, hydroxide, chloride, nitrate, sulfate, phosphate and organic compound.

7. The adjuvant according to claim 6, characterized in that, The metal compound is one or more selected from oxide, orthophosphate, phosphite, basic phosphate and acid phosphate.

8. The adjuvant according to claim 7, characterized in that, The metal is one or more selected from Fe, Zn and Cu.

9. The adjuvant according to any one of claims 1 to 8, characterized in that, The phosphorus aluminum binder is a phosphorus aluminum inorganic binder containing first clay.

10. The adjuvant according to claim 9, characterized in that, The preparation steps of the phosphorus aluminum inorganic binder containing first clay include: (1) dispersing an alumina source and first clay with water into a slurry with a solid content of 8-45 wt%, wherein the alumina source is aluminum hydroxide and / or alumina which can be peptized by acid, and the weight ratio of the first clay to the alumina source in terms of Al2O3 is (greater than 0-40):(15-40); (2) adding concentrated phosphoric acid into the slurry obtained in step (1) under stirring according to a weight ratio of P / Al=1-6; (3) reacting the slurry obtained in step (2) at a temperature of 50-99℃ for 15-90 minutes.

11. The adjuvant according to claim 10, characterized in that, The first clay is at least one selected from kaolin, sepiolite, attapulgite, rectorite, montmorillonite and diatomite.

12. The adjuvant of claim 11, wherein, The first clay is kaolin.

13. The adjuvant of claim 1, wherein, The second clay is at least one selected from kaolin, sepiolite, attapulgite, rectorite, montmorillonite and diatomite; and / or The other inorganic binder is at least one selected from pseudoboehmite, acidified alumina, aluminum sol, silica-aluminum sol and water glass.

14. The adjuvant of claim 1, wherein, The preparation method of the zirconium sol is: (1) preparing a solution of a zirconium source at room temperature with a certain concentration, and stirring uniformly; the concentration of ZrO2 is 0.5-20 wt% in terms of oxide; (2) The stabilizer is added to the above solution in a 1-6 times molar ratio of zirconium, and the solution is stirred at room temperature to 90°C for 0.5-3 hours to allow it to react fully, to obtain a first mixed solution; (3) The base solution is slowly added to the above solution at room temperature to 50°C using a pump, and the pH of the zirconium sol is controlled to be 0-10 by controlling the amount of base solution added, to obtain a clear and transparent zirconium sol.

15. The adjuvant according to claim 14, characterized in that, The pH is 1-7.

16. The aid of claim 15, wherein, The pH is 2-5.

17. The adjuvant of claim 14, wherein, The stabilizer is an organic acid selected from at least one of acetic acid, glycolic acid, oxalic acid, malonic acid, malic acid, tartaric acid, succinic acid, adipic acid, maleic acid, itaconic acid, and citric acid.

18. A process for the preparation of the adjuvant according to any one of claims 1 to 17, characterized in that, Specifically comprising the following steps: (1) The IMF structure molecular sieve, MFI molecular sieve, zirconium sol, inorganic binder, and second clay slurry are mixed, beaten, and introduced into a metal additive, and finally a phosphorus-aluminum binder is added, and spray-dried; (2) Dried and calcined.

19. The method of claim 18, wherein, The drying temperature is room temperature to 400°C, the calcination temperature is 400-700°C, and the calcination time is 0.5-100 hours.

20. The method of claim 19, wherein, The drying temperature is 100-300°C, and the calcination time is 0.5-10 hours.

21. A catalytic cracking catalyst comprising the adjuvant of any one of claims 1-17 or prepared according to the preparation method of any one of claims 18-20.

22. A catalytic cracking method comprising the step of contacting a hydrocarbon oil with the catalytic cracking catalyst of claim 21.

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