Synthesis method and application of SAPO-11 molecular sieve

Abstract

The invention provides a synthesis method and application of an SAPO-11 molecular sieve. The synthesis method comprises the following steps: step 1, coprecipitating a metal salt in an aqueous solution; and 2, mixing the mixture in the step 1 with an alkali solution of natural minerals, a silicon accelerant, an aluminum source, a phosphorus source, a template agent and water, and crystallizing to obtain the SAPO-11 molecular sieve. Natural minerals are adopted as silicon sources, dissolution of silicon is promoted under the action of the silicon accelerant, better cross-linking substances can be formed by the natural minerals, the template agent and coprecipitates, and the utilization rate of silicon is increased. Besides, the metal salt is introduced in a coprecipitation mode, so that the metal salt and the silicon source copolymer can form a stable chelate, the modified metal component is more stable, and loss of metal ions is reduced.

Description

Technical Field

[0001] The present invention relates to the field of oil shale mining, and specifically to a SAPO-11 molecular sieve and its use in a catalyst for in-situ conversion of oil shale. Background Art

[0002] The security situation of China's oil supply is severe. With the increasing difficulty of newly discovered large-scale oil reserves and the decline in the oil production quality of old oil fields, finding alternative areas for oil resources, ensuring stable or even increased crude oil production, and reducing the external dependence on oil have become urgent needs to ensure national energy security. Among various oil resources, shale oil has the advantage of large recoverable reserves (nearly three times the total amount of conventional oil resources), making shale oil the most potential alternative resource. According to the method of obtaining shale oil, it can be divided into surface retorting and underground in-situ conversion. Compared with surface retorting, underground in-situ conversion has advantages such as less pollution and stable yield. Among them, the design and performance of the catalyst in the hydrothermal cracking catalytic viscosity reduction technology are the most important and crucial part of this technology. Due to the relatively small amount of catalyst used, low cost, the ability to be used in combination, and the ability to perform various combinations of ligands and central metals in terms of structure, it determines that it has strong plasticity, great development potential, and wide selectivity. However, there are very few reports on in-situ conversion catalysts at present. Generally, oil shale resources with a burial depth less than 300 m can be mined by open-pit mining and transported to a retorting plant to extract shale oil; while oil shale with a burial depth greater than 300 m is suitable for in-situ heating of the oil shale layer to convert it into shale oil for mining. Currently, the ICP (In-suit Conversion Process) technology of Shell Oil Company is the most mature in the retorting oil technology for in-situ conversion of oil shale.

[0003] Compared with the surface retorting technology, in-situ conversion mining can obtain shale oil without excavating underground oil shale ore to the surface. However, during the conversion process, the oil shale layer needs to be heated to a high temperature of 500 °C to pyrolyze to obtain shale oil, resulting in huge energy consumption. The derivation rate of large molecular hydrocarbons is slow, and organic matter is prone to coking and secondary cracking, reducing the conversion rate and extraction rate of oil in oil shale. However, if a catalyst is added during the in-situ conversion process, the catalyst will significantly change the activation energy in the reaction process, thereby changing the reaction rate and accelerating the reaction. Reducing the temperature required for in-situ oil and gas conversion of oil shale and improving the quality of oil and gas products by adding a catalyst have become an important research and development direction for the industrialization of in-situ conversion of oil shale.

[0004] CN202210225272.6 discloses needle-shaped nano iron-based double metal hydroxides and their application methods for regulating the selectivity of oil shale pyrolysis products at low temperature. The metal cations in its layer board are composed of Fe 3+ and Ni 2+ , Mn 2+ and Co2+ selected from divalent metal cations, and the anions in the interlayer region are composed of OH - , CO 3 2- and OCN - Although the invention can realize the catalytic pyrolysis of oil shale, there are deficiencies such as a single functional component of the catalyst and an insignificant effect of adding metal compounds on improving the component distribution of pyrolysis products.

[0005] CN201410145243.4 discloses a catalyst for oil shale pyrolysis, its preparation method and usage method. The described catalyst is made from the following raw materials by mass percentage: molecular sieve 2% - 8%, activated clay 1% - 5%, organic cobalt salt 10% - 60%, metal sulfide 5% - 20%, glycerate 8% - 30%, paraffin 15% - 35%; the organic cobalt salt is one or more of cobalt acetate, cobalt oxalate, cobalt naphthenate and cobalt neodecanoate; the metal sulfide is molybdenum sulfide and / or nickel sulfide. Although this method can prepare an in-situ conversion catalyst for oil shale, which contains multiple functional components, the stability of the catalyst is lacking.

[0006] In terms of the low-cost synthesis of SAPO-11, CN202110735921.2 discloses a method for green synthesis of hierarchical pore SAPO-11 molecular sieve based on natural minerals and its preparation method. First, thermally activated kaolin is dissolved in orthophosphoric acid solution, and after stirring, deionized water, an additional aluminum source, and a template agent are added. After hydrothermal crystallization, the solid product is obtained by centrifugation, and then the template agent is removed by high-temperature calcination to obtain the molecular sieve. Although this invention adopts the method of obtaining a silicon-aluminum source by treating natural minerals with orthophosphoric acid, there are prominent problems such as insufficient dissolution of the silicon source and low crystallinity of the SAPO-11 molecular sieve. CN201310516817.X discloses a method for continuously synthesizing SAPO-11 molecular sieve by the ionothermal method. An ionic liquid is used as a circulating solvent, and the continuously fed reactants enter a tubular reactor for rapid crystallization after pre-gelation. After washing and separation, the molecular sieve product is obtained, and the ionic liquid and unreacted raw materials are recycled after distillation separation. Among them, although it is mentioned that the silicon source is one or more of solid silica gel, silica sol, white carbon black, kaolin, montmorillonite, sodium silicate and tetraethyl orthosilicate, there is no mention of adding a silicon promoter to introduce soluble divalent metal salts and trivalent salts by coprecipitation, and then forming a stable chelate with the silicon source to stabilize metal ions.

[0007] As can be seen from the above prior art, at present, the research on catalysts for catalytic pyrolysis of oil shale mainly focuses on above-ground retorting technology. Moreover, the deficiencies of the above technology are that the selectivity of the catalyst for heavy fractions is relatively low, and the nitrogen and sulfur contents in the products are high, increasing the subsequent refining and process cost pressure. In many underground in-situ conversion technologies, transition metals such as copper, iron, cobalt, nickel, manganese, zinc, molybdenum, tin, calcium, magnesium and other metal elements, halides, sulfates, carbonates, organic acid salts, etc. are added during the in-situ conversion of oil shale. These metal compounds penetrate into the micropores of oil shale in the form of a solution and have the effect of reducing the cracking temperature. Currently, they are mainly inorganic salts, metal catalysts, metal oxides, sulfides and halide catalysts according to type. However, most of them have problems such as insufficient stability, unremarkable effects, and a large number of components in the catalyst, making the preparation operation of the catalyst complex and costly. Therefore, there is an urgent need to develop a shale oil in-situ conversion catalyst that can stably play the role of metal functional components, reduce the activation energy required for the pyrolysis hydrocarbon generation reaction, thereby changing the reaction path and accelerating the reaction rate, so as to reduce the temperature required for the in-situ oil and gas conversion of oil shale and improve the quality of oil and gas products. Summary of the Invention

[0008] The main object of the present invention is to provide a synthesis method of SAPO-11 molecular sieve and its application in the field of in-situ conversion of shale oil, so as to overcome the defects of weak catalytic performance of the catalyst used for in-situ conversion of oil shale and unstable catalytic effect under high-temperature conditions in the prior art.

[0009] To achieve the above object, the present invention provides a synthesis method of SAPO-11 molecular sieve, which includes the following steps:

[0010] Step 1, performing coprecipitation of metal salts in an aqueous solution;

[0011] Step 2, mixing the mixture obtained in Step 1 with an alkaline solution of natural minerals, a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water, and crystallizing to obtain SAPO-11 molecular sieve.

[0012] In the synthesis method of SAPO-11 molecular sieve of the present invention, the metal salt is nitrate, sulfate, chloride or carbonate formed by at least one of Mg 2+ , Zn 2+ , Cu 2+ , Co 2 + , Ni 2+ , Ca 2+ , Al 3+ , Fe 3+ , Cr 3+ metal ions.

[0013] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the metal salt is Mg 2+ , Zn 2+ , Cu 2+ , Co 2 + , Ni 2+ , Ca 2+ nitrate, sulfate, chloride or carbonate formed by at least one of the metal ions, and Al 3+ , Fe 3+ , Cr 3+ a mixture formed by nitrate, sulfate, chloride or carbonate formed by at least one of the metal ions, in the metal salt, Mg 2+ , Zn 2+ , Cu 2+ , Co 2+ , Ni 2+ and Ca 2+ the molar ratio of the metal ions to Al 3+ , Fe 3+ and Cr 3+ is 1 to 5:1.

[0014] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein step 1 is: mixing an aqueous solution of a metal salt with an aqueous solution of an alkaline substance, controlling the pH value to be 8 to 10, stirring at 60 to 90 °C, and performing coprecipitation; the alkaline substance in the aqueous solution of the alkaline substance is NaOH and / or Na 2 CO 3 , and the mass ratio of NaOH to Na 2 CO 3 is 1:(0.5 to 1).

[0015] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the metal salt coprecipitate prepared in step 1, calculated as metal ions, accounts for 0.7 to 7% of the mass of the SAPO-11 molecular sieve crystallization mixture.

[0016] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the mixture in step 1 is first mixed with an alkaline solution of a natural mineral, and then mixed with a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water.

[0017] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the natural mineral is first calcined and then mixed with an alkaline solution, and treated at 50-100 °C for 0.1-3 h to obtain an alkaline solution of the natural mineral; the natural mineral is one or more of kaolin, rectorite, halloysite, montmorillonite, diatomite, illite, coal gangue, the calcination temperature is 400-1000 °C, and the calcination time is 1-5 hours; the alkaline solution is an ammonia water solution with a mass concentration of 1-25%; the liquid-solid mass ratio in the alkaline solution of the natural mineral is (1-5):1.

[0018] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the silicon promoter is ammonium borate and / or ammonium phosphate, and the addition amount is 0.1-10:100 in molar ratio to the aluminum source, wherein the aluminum source is calculated as aluminum; the template agent is one or more of diethylamine, diisopropylamine and di-n-propylamine.

[0019] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the molar ratio of the crystallization mixture is: 30-100H 2 O: 0.5-3P 2 O 5 : 1.0Al 2 O 3 : 1-10 template agent: 0.05-2.0SiO 2 ; the crystallization temperature is 140-200 °C, and the crystallization time is 20-32 h.

[0020] The synthesis method of the SAPO-11 molecular sieve according to the present invention, wherein the mass ratio of the mixture in step 1 to the aluminum source is (1-50):100; the aluminum source is one or a mixture of alumina, aluminum sulfate, aluminum phosphate, aluminum chloride, aluminum nitrate, aluminum fluoride, aluminum formate, aluminum acetate; the phosphorus source is one or a mixture of phosphoric acid, phosphorous acid, phosphate, phosphorus oxide.

[0021] In order to achieve the above object, the present invention also provides the SAPO-11 molecular sieve obtained by the above synthesis method for use as an in-situ conversion catalyst for oil shale.

[0022] The beneficial effects of the present invention:

[0023] The present invention relates to a method for preparing SAPO-11 molecular sieve and using it as a catalyst for in-situ conversion of shale oil. The ultimate goal of in-situ conversion of shale oil is to break carbon bonds and change the properties of oil-containing substances in shale through the action of a catalyst, thereby achieving the flow of oil and gas and improving the recovery rate. The catalyst is required to have a certain acidity, specific surface area, and pore structure. Moreover, the multi-level pore distribution and the stability of active centers of the catalyst are crucial for the performance of the in-situ conversion catalyst. Most of the silicon sources used in the synthesis of traditional SAPO-11 are silica sol, tetraethyl orthosilicate, etc., which not only bring many problems such as high cost and unsuitability for industrial applications, but also the specific surface area and pore volume of the synthesized SAPO-11 are underdeveloped and cannot meet the requirements of shale in-situ conversion. The present invention uses a natural mineral treated with alkali as a silicon source polymer. On the one hand, it avoids using substances synthesized by chemical methods as silicon sources, having the characteristics of low cost and environmental friendliness. On the other hand, the silicon dissolved from the natural mineral after alkali treatment is in a single-polymer state, which is easily dispersed and utilized in the synthesis. Moreover, the natural mineral after alkali treatment has a rich specific surface area and pore volume, which is very beneficial for efficiently in-situ converting kerogen in shale. The addition of a silicon promoter not only promotes the dissolution of silicon, but also accelerates the cross-linking with the template agent and the coprecipitate, stabilizes the form of silicon, and forms more silicon source points, thereby improving the synthesis efficiency, which lays a foundation for the subsequent improvement of the metal ion retention rate.

[0024] The metal ions in the metal salt are the key components for in-situ conversion of shale oil in the present invention. In the traditional technology, introducing metal salts by coprecipitation is extremely likely to cause the loss of metal salts, resulting in a significant decline in the performance of the in-situ conversion catalyst. In the present invention, metal salts are first introduced by coprecipitation, and then form a stable chelate with the alkali solution of the natural mineral treated with alkali (abbreviated as silicon source copolymer), thereby making the modified metal components more stable, reducing the loss of metal ions, and also reducing the loss of functional components, ensuring the in-situ conversion performance of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 XRD patterns of SAPO-11 molecular sieves synthesized in the examples and comparative examples of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions of the present invention are described in detail below. The following embodiments are implemented on the premise of the technical solutions of the present invention, and the detailed implementation processes are given. However, the protection scope of the present invention is not limited to the following embodiments. For the structures or experimental methods without specific conditions noted in the following embodiments, they are usually in accordance with conventional conditions.

[0027] The present invention provides a method for synthesizing SAPO-11 molecular sieve, including the following steps:

[0028] Step 1, performing coprecipitation of the metal salt in an aqueous solution;

[0029] Step 2: Mix the mixture obtained in Step 1 with an alkaline solution of natural minerals, a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water, and crystallize to obtain SAPO-11 molecular sieve.

[0030] The present invention uses natural minerals as the silicon source, and promotes the dissolution of silicon through the action of a silicon promoter, which can form a better cross-linked substance with the template agent and the coprecipitate, improving the utilization rate of silicon. In addition, the present invention introduces metal salts by coprecipitation, enabling the metal salts to form stable chelates with the silicon source copolymer, thereby making the modified metal components more stable and reducing the loss of metal ions.

[0031] In one embodiment, the metal salt is a soluble metal salt, more specifically a soluble divalent metal salt or trivalent metal salt. The present invention does not make a special limitation on "soluble", which generally means soluble in water.

[0032] In another embodiment, the divalent metal salt is a nitrate, sulfate, chloride, or carbonate of a divalent metal. The divalent metal is, for example, Mg 2+ 、Zn 2+ 、Cu 2+ 、Co 2+ 、Ni 2+ 、Ca 2+ Any one of them. The trivalent metal salt is a nitrate, sulfate, chloride, or carbonate of a trivalent metal. The trivalent metal ion is Al 3+ 、Fe 3+ 、Cr 3+ Any one of them.

[0033] In yet another embodiment, the metal salt of the present invention is a mixture of a divalent metal salt and a trivalent metal salt. The divalent metal salt and the trivalent metal salt are respectively calculated based on metal ions, and the molar ratio of the divalent metal salt to the trivalent metal salt is 1 to 5:1.

[0034] In one embodiment, the coprecipitation of the metal salt in an aqueous solution is specifically: mixing an aqueous solution of the metal salt with an aqueous solution of an alkaline substance, controlling the pH value to be 8 to 10, and stirring at 60 to 90 °C for coprecipitation. In another embodiment, the aqueous solution of the metal salt is added to the aqueous solution of the alkaline substance, controlling the pH value to be 8 to 10, and stirring for 2 - 5 h for coprecipitation.

[0035] In one embodiment, the alkaline substance in the aqueous solution of the alkaline substance is NaOH and / or Na 2 CO 3 . Preferably, the alkaline substance is a mixture of NaOH and Na 2 CO 3 , and the mixture of NaOH and Na 2 CO 3The mass ratio is 1:(0.5 - 1). In another embodiment, the concentration of NaOH in the aqueous solution of the alkaline substance is 1.0 - 6.0 mol / L. In yet another embodiment, the metal salt coprecipitate prepared in step 1, calculated as metal ions, accounts for 0.7 - 7% of the mass of the SAPO-11 molecular sieve crystallization mixture.

[0036] In the present invention, the method for preparing the alkaline solution of the natural mineral is as follows: The natural mineral is first calcined and then mixed with an alkaline solution, and treated at 50 - 100 °C for 0.1 - 3 h to obtain the alkaline solution of the natural mineral.

[0037] In one embodiment, the natural mineral is one or more of kaolin, rectorite, halloysite, montmorillonite, diatomite, illite, and coal gangue. The calcination temperature is 400 - 1000 °C, preferably 800 - 1000 °C, and the calcination time is 1 - 5 hours; the alkaline solution is an aqueous ammonia solution with a mass concentration of 1 - 25%; the liquid-solid mass ratio in the alkaline solution of the natural mineral is (1 - 5):1.

[0038] In one embodiment, the mixture in step 1 of the present invention is first mixed with the alkaline solution of the natural mineral, and then mixed with a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water. In another embodiment, the mass ratio of the mixture in step 1 to the aluminum source is (1 - 50):100.

[0039] Among them, the silicon promoter is ammonium borate and / or ammonium phosphate, and the addition amount is in a molar ratio of 0.1 - 10:100 to the aluminum source, where the aluminum source is calculated as aluminum. The template agent is one or more of diethylamine (DEA), diisopropylamine (DIPA), and di-n-propylamine (DPA). The aluminum source is one or a mixture of alumina, aluminum sulfate, aluminum phosphate, aluminum chloride, aluminum nitrate, aluminum fluoride, aluminum formate, and aluminum acetate. The phosphorus source is one or a mixture of phosphoric acid, phosphorous acid, phosphates, and phosphorus oxides.

[0040] In one embodiment, the molar ratio of the crystallization mixture is: 30 - 100H 2 O:0.5 - 3P 2 O 5 :1.0Al 2 O 3 :1 - 10 template agent:0.05 - 2.0SiO 2 ; The crystallization temperature is 140 - 200 °C, and the crystallization time is 20 - 32 h.

[0041] In a specific embodiment, the synthesis method of the SAPO-11 molecular sieve of the present invention is as follows:

[0042] 1) The natural mineral is calcined at 400 - 1000 °C for 1 - 5 hours, and then fully mixed with a certain concentration of alkaline solution for 30 min to obtain a solid-liquid mixture A.

[0043] 2) Uniformly disperse divalent and trivalent soluble metal salts in water to prepare salt solution B; uniformly disperse alkaline substances in water to prepare alkali solution C. Subsequently, under stirring at 60 - 90 °C, add solution B to solution C, control the pH value at 8 - 10, and continue stirring for 2 - 5 h to obtain mixture D.

[0044] 3) Add mixture D to the solid - liquid mixture A, mix well for 30 min, and then add a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water for the synthesis of SAPO - 11. The ratio of the synthesis gel is: 30 - 100H 2 0:0.5 - 3P 2 O 5 :1.0Al 2 O 3 :1 - 10Template:0.05 - 2.0SiO 2 。

[0045] 4) Place the mixed gel in a sealed reaction kettle and crystallize it at 140 - 200 °C for 20 - 32 h, then filter and wash with water to obtain SAPO - 11 molecular sieve.

[0046] The SAPO - 11 molecular sieve synthesized by the method of the present invention uses natural minerals as the silicon - source polymer. On the one hand, it avoids using substances synthesized by chemical methods as the silicon source, featuring low cost and environmental friendliness. On the other hand, the silicon dissolved out from the natural minerals after alkali treatment is in a single - polymer state, which is easily dispersed and utilized in the synthesis. Moreover, the natural minerals after alkali treatment have a rich specific surface area and pore volume, which are very beneficial for the efficient in - situ conversion of kerogen in shale. The addition of the silicon promoter not only promotes the dissolution of silicon but also accelerates the cross - linking with the template agent and the coprecipitate, forming a porous substance with a network - like and cross - linked structure containing more silicon - source points, so that the synthesized molecular sieve includes both active components and matrix components, thus ensuring that the finally synthesized SAPO - 11 contains a rich pore structure, gradient pore distribution, and acidic gradient distribution; the addition of the silicon promoter not only promotes the dissolution of silicon but also accelerates the cross - linking with the template agent and the coprecipitate, stabilizes the form of silicon, and forms more silicon - source points, thereby improving the synthesis efficiency, which lays a foundation for the subsequent improvement of the metal - ion retention rate; the metal salts introduced by the coprecipitation method can form stable chelates with the silicon - source copolymer after alkali treatment, further making the modified metal components more stable, reducing the loss of metal ions, and ensuring the in - situ conversion performance of the catalyst.

[0047] The above technical implementation ensures that when SAPO-11 is used as a composite catalytic material for in-situ conversion catalysts of oil shale, it has the characteristics of reasonable acid distribution, difficult loss of functional metals, slow release, and continuous effectiveness. After the catalyst containing the SAPO-11 molecular sieve of the present invention is mixed with oil shale, due to the high content of the synthesized molecular sieve, more developed specific surface area and pore volume, and good retention rate of metal ions, the temperature reduction amplitude at the maximum weight loss is reduced by 30-45 °C compared with the case without the SAPO-11 molecular sieve of the present invention, indicating that the technical implementation of the present invention significantly reduces the conversion temperature required for in-situ conversion of shale oil. Among them, the temperature reduction at the maximum weight loss is an important indicator for characterizing the improvement of in-situ conversion performance. Therefore, the catalyst of the SAPO-11 molecular sieve of the present invention has excellent conversion performance and good stability when used for catalytic conversion of oil shale.

[0048] The technical solution of the present invention will be further described in detail through specific examples below. Source of raw materials:

[0049] 1) Natural minerals such as kaolin and montmorillonite: industrial products, commercially available, purchased from Suzhou Kaolin Company, China

[0050] 2) Ammonia water solution: concentration 28% (mass percentage), chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0051] 3) Magnesium nitrate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0052] 4) Iron nitrate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0053] 5) Aluminum nitrate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0054] 6) Zinc sulfate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0055] 7) Iron sulfate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0056] 8) Copper chloride: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0057] 9) Chromium chloride: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0058] 10) Nickel carbonate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0059] 11) Cobalt sulfate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0060] 12) Calcium nitrate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0061] 13) Chromium sulfate: chemically pure, Sinopharm Chemical Reagent Co., Ltd.

[0062] 14) Chromium chloride: chemically pure, from Sinopharm Chemical Reagent Co., Ltd.

[0063] 15) Magnesium chloride: chemically pure, from Sinopharm Chemical Reagent Co., Ltd.

[0064] 16) Ammonium borate: chemically pure, from Sinopharm Chemical Reagent Co., Ltd.

[0065] 17) Ammonium phosphate: chemically pure, from Sinopharm Chemical Reagent Co., Ltd.

[0066] 18) Aluminum oxide: industrial grade, from the Catalyst Division of Lanzhou Petrochemical Company (Al 2 O 3 Mass percentage: 98%)

[0067] 19) Aluminum sulfate: industrial grade, from the Catalyst Division of Lanzhou Petrochemical Company (Al 2 O 3 Mass percentage: 7.10%)

[0068] 20) Phosphorus source: chemically pure, from Sinopharm Chemical Reagent Co., Ltd.

[0069] 21) Silicon powder: chemically pure, from Qingdao Jinyang Fine Chemical Co., Ltd.

[0070] 22) Diethylamine (DEA): analytical pure, 500 mL, ≥98.5% (mass percentage), from Sinopharm Chemical Reagent Co., Ltd.

[0071] 23) Diisopropylamine (DIPA): analytical pure, 250 mL, ≥98.0% (mass percentage), from Sinopharm Chemical Reagent Co., Ltd.

[0072] 24) Di-n-propylamine (DPA): 250 mL, ≥99.0% (mass percentage), analytical pure, from Sinopharm Chemical Reagent Co., Ltd.

[0073] Specific analysis method:

[0074] The crystallinity of SAPO-11 molecular sieve was tested on a D / max-3C type X-ray powder diffractometer manufactured by Rigaku Corporation of Japan. The crystallinity of the sample was determined by X-ray diffraction method. Taking the characteristic diffraction peaks of the SAPO-11 standard sample at 2θ = 8.1°, 9.4°, 13.1°, 15.6°, 20.3°, 21.2°, 22.1°, 22.8°, 23.2°, etc. as the standard, the ratio of the peak areas obtained by comparing the synthesized sample with it was used as the final crystallinity value.

[0075] BET characterization is used to determine the specific surface area and pore volume of the sample. In this invention, an ASAP 2460 full-automatic specific surface area analyzer produced by Micromeritics Company of the United States is adopted. Test method: First, the sample is pretreated (in a vacuum state) at a high temperature (300 °C) for 8 hours; then, when the liquid nitrogen temperature is -196 °C, the sample is analyzed. The total specific surface area data measured is calculated by the BET method, while the remaining surface area and micropore volume data are calculated by the t-plot method, and the mesopore volume is calculated by the BJH method.

[0076] TG-DSC characterization is used to determine the change of the sample mass with temperature, so as to determine the thermal stability performance of the sample. The DSC curve is obtained by differentiating the TG curve. In this invention, a Themys TGA synchronous thermal analyzer produced by Setaram Company of France is adopted. Test method: First, zero the crucible in the instrument, then put in the sample (5 - 10 mg), and heat it to 800 °C at a rate of 20 °C.

[0077] Elemental characterization: For elemental determination, a ZSX-Primus-II X-ray fluorescence spectrometer produced by Rigaku Company of Japan is used. Tube voltage: 50 KV, current: 50 mA.

[0078] Example 1

[0079] 1) Weigh 50 grams of diatomite and calcine it at 750 °C for 3.5 hours, then fully mix it with 50 grams of ammonia water solution with a mass percentage concentration of 5% and treat it at 50 °C for 3 hours to obtain a solid-liquid mixture A1. 2) Dissolve 14.8 g of magnesium nitrate and 37.5 g of aluminum nitrate in 100 ml of distilled water to form a mixture solution B1 of divalent salt and trivalent salt; measure 50 ml of distilled water, add 4 g of sodium hydroxide and 2 g of sodium carbonate, dissolve them thoroughly and make up the volume to 100 ml to prepare a solution C1 with a NaOH concentration of 1 mol / L. Solution B1 and C1 are jointly dripped into 20 ml of distilled water, control the pH value to 9.1, after dripping, continue to stir for 5 hours to form a mixture D1. 3) Weigh 5.1 grams of mixture D1, 10 grams of A1 solution, 0.03 grams of silicon promoter ammonium borate, 34.2 grams of aluminum sulfate, 9.8 grams of phosphoric acid, 7.41 grams of diethylamine and 37 grams of water, crystallize at 140 °C for 32 hours, filter and wash with water to obtain the final product S1. The product S1 is tested and characterized, and the results are shown in Table 1.

[0080] Example 2

[0081] 1) Weigh 40 g of kaolin and calcine it at 1000 °C for 1.5 h, then mix it thoroughly with 120 g of an ammonia water solution with a mass percentage concentration of 25%, and treat it at 100 °C for 0.1 h to obtain a solid-liquid mixture A2. 2) Dissolve 8.07 g of zinc sulfate and 20 g of ferric sulfate in 100 ml of distilled water to form a mixture solution B2 of divalent and trivalent salts; measure 50 ml of distilled water, add 24 g of sodium hydroxide and 12 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C2 with a NaOH concentration of 6 mol / L. Solution B2 and C2 are jointly added dropwise to 20 ml of distilled water, controlling the pH value to be 9.5. After the addition is completed, continue stirring for 7 h to form a mixture D2. 3) Crystallize 0.1 g of mixture D2, 101 g of diisopropylamine, 60 g of solution A2, 2.03 g of the silicon promoter ammonium phosphate, 10.7 g of pseudoboehmite, 49.2 g of phosphorous acid and 60 g of water at 180 °C for 20 h, filter and wash with water to obtain the final product S2. The product S2 is tested and characterized, and the results are shown in Table 1.

[0082] Example 3

[0083] 1) Weigh 35 g of rectorite and calcine it at 700 °C for 3.5 h, then mix it thoroughly with 175 g of an ammonia water solution with a mass percentage concentration of 28%, and treat it at 80 °C for 2 h to obtain a solid-liquid mixture A3. 2) Dissolve 20.17 g of copper chloride and 7.92 g of chromium chloride in 100 ml of distilled water to form a mixture solution B3 of divalent and trivalent salts; measure 50 ml of distilled water, add 12 g of NaOH and 7.2 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C3 with a NaOH concentration of 3 mol / L. Solution B3 and C3 are jointly added dropwise to 20 ml of distilled water, controlling the pH value to be 9.2. After the addition is completed, continue stirring for 5 h to form a mixture D3. 3) Crystallize 2.04 g of mixture D3, 50.6 g of di-n-propylamine, 30 g of solution A3, 0.77 g of the silicon promoter ammonium carbonate, 12.20 g of aluminum phosphate, 36.59 g of ammonium phosphate and 124 g of water at 170 °C for 28 h, filter and wash with water to obtain the final product S3. The product S3 is tested and characterized, and the results are shown in Table 1.

[0084] Example 4

[0085] 1) Weigh 46 g of attapulgite, calcine it at 890 °C for 3 h, then mix it thoroughly with 184 g of an ammonia water solution with a mass percentage concentration of 16%, and treat it at 60 °C for 1.5 h to obtain a solid-liquid mixture A4. 2) Dissolve 23.74 g of nickel carbonate and 24.19 g of iron nitrate in 100 ml of distilled water to form a mixture solution B4 of divalent and trivalent salts; measure 50 ml of distilled water, add 8 g of NaOH and 5.6 g of sodium carbonate, dissolve them completely, and make up the volume to 100 ml to prepare a solution C4 with a NaOH concentration of 2 mol / L. Solution B4 and C4 are added dropwise to 20 ml of distilled water, and the pH value is controlled to be 8.9. After the addition is completed, continue stirring for 6 h to form a mixture D4. 3) Crystallize 0.15 g of mixture D4, a mixture of 40.46 g of diisopropylamine and 29.25 g of diethylamine, 36 g of solution A4, 0.41 g of the silicon promoter ammonium borate, 13.33 g of aluminum chloride, 54.87 g of ammonium pyrophosphate, and 10 g of water at 180 °C for 22 h, filter and wash with water to obtain the final product S4. The product S4 is tested and characterized, and the results are shown in Table 1.

[0086] Example 5

[0087] 1) Weigh 30 g of montmorillonite, calcine it at 500 °C for 2 h, then mix it thoroughly with 60 g of an ammonia water solution with a mass percentage concentration of 13%, and treat it at 70 °C for 1 h to obtain a solid-liquid mixture A5. 2) Dissolve 6.20 g of cobalt sulfate and 1.33 g of aluminum chloride in 100 ml of distilled water to form a mixture solution A5 of divalent and trivalent salts. Measure 50 ml of distilled water, add 20 g of NaOH and 16 g of sodium carbonate, dissolve them completely, and make up the volume to 100 ml to prepare a solution B5 with a NaOH concentration of 5 mol / L. Solution B5 and C5 are added dropwise to 20 ml of distilled water, and the pH value is controlled to be 8.7. After the addition is completed, continue stirring for 7 h to form a mixture D5. 3) Crystallize 2.55 g of mixture D5, a mixture of 15.18 g of diisopropylamine and 11 g of diethylamine, 12 g of solution A5, 0.41 g of the silicon promoter ammonium phosphate, 21.30 g of aluminum nitrate, 21.29 g of phosphorus pentoxide, and 130 g of water at 160 °C for 26 h, filter and wash with water to obtain the final product S5. The product S5 is tested and characterized, and the results are shown in Table 1.

[0088] Example 6

[0089] 1) Weigh 40 g of illite and calcine it at 600 °C for 4 h. Then, mix it thoroughly with 40 g of an ammonia water solution with a mass percentage concentration of 18% and treat it at 90 °C for 2.5 h to obtain a solid-liquid mixture A6. 2) Dissolve 24.61 g of calcium nitrate and 39.2 g of chromium sulfate in 100 ml of distilled water to form a mixture solution B6 of divalent salt and trivalent salt; measure 50 ml of distilled water, add 16 g of NaOH and 14.4 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C6 with a NaOH concentration of 4 mol / L. Solution B6 and C6 are jointly added dropwise to 20 ml of distilled water, and the pH value is controlled at 8.5. After the addition is completed, continue to stir for 5 h to form a mixture D6. 3) Crystallize 3.57 g of mixture D6, 14.63 g of diethylamine, 20.24 g of di-n-propylamine, 90 g of solution A6, 3.57 g of silicon promoter ammonium borate, 8.40 g of aluminum fluoride, 49 g of phosphoric acid and 46 g of water at 150 °C for 30 h, filter and wash with water to obtain the final product S6. The product S6 is tested and characterized, and the results are shown in Table 1.

[0090] Example 7

[0091] 1) Weigh 60 g of coal gangue and calcine it at 970 °C for 4 h. Then, mix it thoroughly with 120 g of an ammonia water solution with a mass percentage concentration of 8% and treat it at 65 °C for 0.3 h to obtain a solid-liquid mixture A7. 2) Dissolve 10.18 g of nickel nitrate and 4 g of chromium nitrate in 100 ml of distilled water to form a mixture solution B7 of divalent salt and trivalent salt. Measure 50 ml of distilled water, add 10 g of NaOH and 6.5 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C7 with a NaOH concentration of 2.5 mol / L. Solution B7 and C7 are jointly added dropwise to 20 ml of distilled water, and the pH value is controlled at 9.3. After the addition is completed, continue to stir for 7 h to form a mixture D7. 3) Crystallize 1.02 g of mixture D7, 70.83 g of di-n-propylamine, 3.16 g of solution A7, 1.42 g of silicon promoter ammonium phosphate, 20.41 g of aluminum acetate, 27.88 g of metaphosphoric acid and 18 g of water at 165 °C for 28 h, filter and wash with water to obtain the final product S7. The product S7 is tested and characterized, and the results are shown in Table 1.

[0092] Example 8

[0093] 1) Weigh 35 g of kaolin and calcine it at 930 °C for 4.5 h, then mix it thoroughly with 105 g of an ammonia water solution with a mass percentage concentration of 22%, and treat it at 85 °C for 1.8 h to obtain a solid-liquid mixture A8. 2) Dissolve 2.38 g of magnesium chloride and 2.66 g of chromium chloride in 100 ml of distilled water to form a mixture solution B8 of divalent salt and trivalent salt; measure 50 ml of distilled water, add 18 g of NaOH and 15.3 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C8 with a NaOH concentration of 4.5 mol / L. Solution B8 and C8 are jointly added dropwise to 20 ml of distilled water, and the pH value is controlled to be 9.6. After the addition is completed, continue stirring for 6 h to form a mixture D8. 3) Crystallize 0.82 g of mixture D8, 43.88 g of diethylamine, 10 g of solution A8, 0.58 g of silicon promoter ammonium carbonate, 16.27 g of aluminum formate, 27.44 g of phosphoric acid, and 23 g of water at 180 °C for 30 h, filter and wash with water to obtain the final product S8. The product S8 is tested and characterized, and the results are shown in Table 1.

[0094] Comparative Example 1

[0095] Compare with Example 4. This comparative example does not contain a silicon source polymer treated with natural mineral alkali. 1) Weigh 30 g of silica sol (SiO 2 with a mass percentage content of 30%) and stir for use. 2) Dissolve 23.74 g of nickel carbonate and 24.19 g of iron nitrate in 100 ml of distilled water to form a mixture solution B4 of divalent salt and trivalent salt; measure 50 ml of distilled water, add 8 g of NaOH and 5.6 g of sodium carbonate, dissolve them thoroughly and then make up the volume to 100 ml to prepare a solution C4 with a NaOH concentration of 2 mol / L. Solution B4 and C4 are jointly added dropwise to 20 ml of distilled water, and the pH value is controlled to be 8.9. After the addition is completed, continue stirring for 6 h to form a mixture D4. 3) Crystallize 0.15 g of mixture D4, a mixture of 40.46 g of diisopropylamine and 29.25 g of diethylamine, 30 g of silica sol, 0.41 g of silicon promoter ammonium borate, 13.33 g of aluminum chloride, 54.87 g of ammonium pyrophosphate, and 10 g of water at 180 °C for 22 h, filter and wash with water to obtain the final product S9. The product S9 is tested and characterized, and the results are shown in Table 1.

[0096] Comparative Example 2

[0097] Comparing with Example 7, this comparative example does not include the co-precipitation treatment step of alkaline substances and metal salts. 1) Weigh 60 grams of coal gangue and calcine it at 970 °C for 4 hours, then fully mix it with 120 grams of ammonia water solution with a mass percentage concentration of 8% and treat it at 65 °C for 0.3 hours to obtain a solid-liquid mixture A7. 2) Dissolve 10.18 g of nickel nitrate and 4 g of chromium nitrate in 100 ml of distilled water to form a mixture solution D9 of divalent salt and trivalent salt. 3) Crystallize 1.02 grams of the mixture solution D9, 70.83 grams of di-n-propylamine, 3.16 grams of solution A7, 1.42 grams of silicon promoter ammonium phosphate, 20.41 grams of aluminum acetate, 27.88 grams of metaphosphoric acid and 18 grams of water at 165 °C for 28 hours, filter and wash with water to obtain the final product S10. The product S10 was tested and characterized, and the results are shown in Table 1.

[0098] Table 1 Characterization results of the synthesized SAPO-11 molecular sieve

[0099]

[0100] Figure 1 This is the XRD pattern of the SAPO-11 molecular sieve synthesized in the examples and comparative examples of the present invention. Table 1 shows the characterization results of the SAPO-11 molecular sieve synthesized in the examples and comparative examples of the present invention. As Figure 1 shown, the molecular sieve prepared by the method of the present invention is a pure-phase molecular sieve without other miscellaneous crystals. As shown in Table 1, comparing Example 4 with Comparative Example 1, using the silicon polymer treated with natural mineral alkali as the silicon source not only increases the crystallinity by 5 units, but also due to the hierarchical pore distribution and rich specific surface area provided after the treatment with natural mineral alkali, the specific surface area and total pore volume of the synthesized SAPO-11 molecular sieve increase by 65 m 2 / g and 0.16 mL / g respectively. The metal salt introduced by the co-precipitation method can form a stable chelate with the copolymer of the silicon source after alkali treatment, thereby making the modified metal component more stable, reducing the loss of metal ions, increasing the functional metal component by 7.5%, and ensuring the continuous effective function of the catalyst.

[0101] Comparing Example 7 with Comparative Example 2, using the copolymer of the silicon source of the alkali-treated natural mineral as the silicon source can significantly improve the crystallinity, specific surface area and pore volume of the synthesized molecular sieve. Moreover, after the co-precipitation of the alkaline compound and the metal salt, together with the silicon promoter, the state of the metal ions is stabilized and the loss is reduced, so that the retention rate of the metal ions is greatly increased by 22.7%. The stable state of the metal ions promotes the performance of the in-situ conversion catalyst, and the temperature reduction amplitude at the maximum weight loss reaches 19 °C, showing excellent in-situ conversion performance.

[0102] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention. However, these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for synthesizing SAPO-11 molecular sieve, characterized in that, it comprises the following steps: Step 1, performing coprecipitation of metal salts in an aqueous solution; Step 2, mixing the mixture obtained in Step 1 with an alkaline solution of natural minerals, a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water, and crystallizing to obtain SAPO-11 molecular sieve.

2. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The metal salt is Mg 2+ , Zn 2+ , Cu 2+ , Co 2+ , Ni 2+ , Ca 2+ , Al 3+ , Fe 3+ , Cr 3+ Nitrates, sulfates, chlorides or carbonates formed by at least one of the metal ions.

3. The method for synthesizing SAPO-11 molecular sieve according to claim 2, characterized in that, The metal salt is Mg 2+ , Zn 2+ , Cu 2+ , Co 2+ , Ni 2+ , Ca 2+ nitrate, sulfate, chloride or carbonate formed by at least one of the metal ions, and Al 3+ , Fe 3+ , Cr 3+ a mixture formed by nitrate, sulfate, chloride or carbonate formed by at least one of the metal ions, among the metal salts, Mg 2+ , Zn 2+ , Cu 2+ , Co 2+ , Ni 2+ and Ca 2+ the molar ratio of the metal ions to Al 3+ , Fe 3+ and Cr 3+ metal ions is 1 to 5:

1.

4. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, Step 1 is: mixing an aqueous metal salt solution with an aqueous alkaline substance solution, controlling the pH value to be 8-10, stirring at 60-90 °C to perform coprecipitation; the alkaline substance in the aqueous alkaline substance solution is NaOH and / or Na 2 CO 3 , and the mass ratio of NaOH to Na 2 CO 3 is 1:(0.5-1).

5. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The metal salt coprecipitate prepared in Step 1, calculated as metal ions, accounts for 0.7-7% of the mass of the SAPO-11 molecular sieve crystallization mixture.

6. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The mixture in Step 1 is first mixed with the alkaline solution of natural minerals, and then mixed with a silicon promoter, an aluminum source, a phosphorus source, a template agent, and water.

7. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The natural mineral is first calcined, then mixed with an alkaline solution, and treated at 50-100 °C for 0.1-3 h to obtain an alkaline solution of natural minerals; the natural mineral is one or more of kaolin, rectorite, halloysite, montmorillonite, diatomite, illite, coal gangue, the calcination temperature is 400-1000 °C, and the calcination time is 1-5 hours; the alkaline solution is an ammonia water solution with a mass concentration of 1-25%; the liquid-solid mass ratio in the alkaline solution of natural minerals is (1-5):

1.

8. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The silicon promoter is ammonium borate and / or ammonium phosphate, and the addition amount is in a molar ratio of 0.1-10:100 to the aluminum source, where the aluminum source is calculated as aluminum; the template agent is one or more of diethylamine, diisopropylamine, and di-n-propylamine.

9. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The molar ratio of the crystallization mixture is: 30 - 100 H 2 O: 0.5 - 3 P 2 O 5 : 1.0 Al 2 O 3 : 1 - 10 template agent: 0.05 - 2.0 SiO 2 ; The crystallization temperature is 140 - 200 °C and the crystallization time is 20 - 32 h.

10. The method for synthesizing SAPO-11 molecular sieve according to claim 1, characterized in that, The mass ratio of the mixture in Step 1 to the aluminum source is (1-50):100; the aluminum source is one or a mixture of alumina, aluminum sulfate, aluminum phosphate, aluminum chloride, aluminum nitrate, aluminum fluoride, aluminum formate, and aluminum acetate; the phosphorus source is one or a mixture of phosphoric acid, phosphorous acid, phosphates, and phosphorus oxides.

11. The SAPO-11 molecular sieve obtained by the synthesis method according to any one of claims 1-10 is used as an in-situ conversion catalyst for oil shale.

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