Nickel-based molecular sieve catalyst prepared by ammonia distillation / in-situ synthesis method and preparation method thereof

Abstract

The invention relates to the technical field of molecular sieve catalyst preparation, in particular to a nickel-based molecular sieve catalyst prepared through an ammonia distillation / in-situ synthesis method and a preparation method thereof.According to the nickel-based molecular sieve catalyst prepared through the ammonia distillation / in-situ synthesis method obtained through the preparation method, the dispersity of the active ingredient nickel in a molecular sieve is high, the active surface area is increased, and the activity of the molecular sieve catalyst is improved; the catalyst is applied to a methanol coupling light hydrocarbon olefin preparation reaction system, the yield of the product olefin is increased, the stability is improved, the performance of the regenerated catalyst is equivalent to that of a fresh catalyst, meanwhile, the preparation cost is low, the preparation process is simple, and the catalyst is suitable for industrial production. The problems that an existing metal-loaded molecular sieve catalyst is prone to carbon deposition and deactivation, low in product yield and poor in catalyst regeneration performance can be effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of molecular sieve catalyst preparation, and is a nickel-based molecular sieve catalyst prepared by an ammonia evaporation / in-situ synthesis method and a preparation method thereof. Background Art

[0002] ZSM-5 zeolite molecular sieve has a three-dimensional cross "Z" shaped pore structure. Because the catalyst has suitable pores and acid properties and good anti-coking ability, it is often used as the main active component or carrier of the catalyst. However, the microporous structure and large particle size of ZSM-5 molecular sieve make it difficult for methanol molecules to contact the reaction center and the product to diffuse. In addition, its acid distribution is uneven, which easily produces a large amount of non-target products, and quickly produces carbon deposits, resulting in a shortened catalyst life. In order to improve the stability and activity of the catalyst, and at the same time improve the selectivity and yield of light olefins, the in-situ synthesis method is currently often used to load metals on ZSM-5 molecular sieves, which can improve its mass transfer and adjust its acid properties, thereby improving its catalytic performance.

[0003] Low-carbon olefins are important basic raw materials for petrochemicals. Their downstream products include polyethylene (PE), ethylene glycol, ethylene oxide, styrene, polyvinyl chloride (PVC), etc., which are used in packaging, agriculture, construction, electronic appliances, machinery and automobile industries. At present, there are three main ways to produce low-carbon olefins: petrochemicals, coal chemicals and natural gas synthesis. Among them, catalytic cracking of petroleum to produce low-carbon olefins is the most common production method.

[0004] In recent years, the preparation of low-carbon olefins has mostly adopted the cracking method of C3 to C12 light hydrocarbon resources (light hydrocarbons and naphtha). However, the reaction of light hydrocarbons to olefins is an endothermic reaction, accompanied by high energy consumption, low yield and high temperature. The development of this method is hindered. Therefore, how to solve the problem of efficient utilization of light hydrocarbons is the key to this method. In addition to the use of light hydrocarbon catalytic cracking to produce ethylene, the most successful non-petroleum route to produce light olefins is the MTO and MTP methods using methanol as raw materials. Methanol can be produced from coal, natural gas or biomass. The product of MTO technology is mainly a mixture of low-carbon olefins such as ethylene and propylene, while the product of MTP technology is mainly propylene. Since methanol to olefins is a highly exothermic reaction, the adiabatic temperature rise is as high as 400 ° C or more, and the heat exchange requirements for fixed bed reactors are very high. Therefore, if methanol and light hydrocarbon resources are mixed to prepare low-carbon olefins, on the one hand, the methanol and light hydrocarbon reactions can be thermally coupled; on the other hand, the lower value-added alkanes can be fully utilized, which may improve the selectivity or yield of low-carbon olefins and extend the single-pass life of the catalyst.

[0005] A Chinese patent document with publication number CN106745050A discloses a method for in-situ synthesis of precious metal-loaded ZSM-5 molecular sieves, the method comprising the following steps: stirring and mixing an aluminum source, water, a template solution and a precious metal salt solution, adding a silicon source, stirring and mixing the mixture to crystallize in a reactor to obtain a crystal, and washing and drying to obtain the precious metal-loaded molecular sieve.

[0006] A Chinese patent document with publication number CN113731478A discloses a Zn-ZSM-5 / ZSM-11 catalyst and a preparation method thereof. The method utilizes a one-step in-situ synthesis method, comprising: (1) adding a silicon source and an alkali raw material into water to obtain a mixed solution A; (2) adding an aluminum source, a template agent and a zinc source into the mixed solution A, and refluxing the reaction system at 80° C. to 150° C. for 2 to 8 hours to obtain a mixed solution B; (3) subjecting the mixed solution B to a crystallization reaction at 130° C. to 170° C. for 18 to 96 hours to obtain a mixed solution C; (4) cooling the mixed solution C to room temperature, filtering, washing and drying, and subjecting the obtained solid product to a first calcination treatment to obtain a catalyst precursor; and (5) subjecting the catalyst precursor to ammonium exchange, and subjecting the exchange product to a second calcination treatment to obtain a Zn-ZSM-5 / ZSM-11 catalyst. Although the one-step reduction method is simple to load metals, it simplifies the preparation process of traditional zeolite molecular sieve loaded metal catalysts, eliminates the steps of calcination and H2 reduction, reduces operating costs, and the prepared molecular sieve is significantly better than the metal-loaded molecular sieve prepared by the traditional impregnation method. However, in this process, the metal active components cannot be completely and evenly spread and dispersed on the carrier, making the active metal particles on the carrier easily aggregated, resulting in problems such as reduced catalyst activity and reduced stability. Summary of the invention

[0007] The present invention provides a nickel-based molecular sieve catalyst prepared by an ammonia evaporation / in-situ synthesis method and a preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of low catalytic activity and low stability of the existing nickel-based catalysts.

[0008] One of the technical solutions of the present invention is achieved by the following measures: A nickel-based molecular sieve catalyst prepared by an ammonia evaporation / in-situ synthesis method is obtained by the following method: S1, add silicon source and alkali source to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source, ZSM-5 seed crystal and template agent to deionized water in sequence and stirring evenly to form solution b; S3, adding solution b dropwise into solution a, stirring and mixing evenly to form gel solution A; S4, dissolving the nickel salt in deionized water to obtain a nickel salt aqueous solution, and adjusting the pH of the nickel salt aqueous solution with ammonia water to obtain a nickel ammonia solution B; S5, adding the nickel ammonia solution B to the gel solution A in a sealed state with stirring, and then heating to evaporate ammonia to obtain a mixed gel solution C; S6, subjecting the mixed gel solution C to a crystallization reaction, filtering the obtained reaction product, washing it to neutrality, and then drying and calcining it once to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt solution for ammonium exchange, filtering and washing the impregnated catalyst precursor until the pH is 5 to 8, and then drying and calcining the catalyst precursor twice to obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0009] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The molar ratio of the silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water is (30 to 290): (0.4 to 28): 1: (5.5 to 31): (2500 to 6500).

[0010] The mass ratio of the above ZSM-5 seed crystal to the template is 1:(0.5 to 5.0).

[0011] The silicon source is one or more of silica sol, silica gel, tetraethyl orthosilicate, sodium silicate nonahydrate and fumed silica.

[0012] The alkali source is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide.

[0013] The aluminum source is one or more of aluminum sulfate, sodium metaaluminate, aluminum chloride, aluminum nitrate, aluminum isopropoxide and aluminum oxide.

[0014] The template agent is one or more of n-butylamine, ethylenediamine, tetrabutylammonium hydroxide and hexadecyltrimethylammonium bromide.

[0015] The molar ratio of silicon to aluminum in the above ZSM-5 seed crystals is 30, 150 or 300.

[0016] The nickel salt is one of Ni(NO3)2·6H2O and NiSO4·6H2O.

[0017] In the above step S4, the pH value of the nickel salt aqueous solution is adjusted to 9 to 12 with ammonia water having a mass concentration of 20% to 30%, thereby obtaining a nickel ammonia solution B having a nickel concentration of 0.1 mol / L to 4.0 mol / L.

[0018] In the above step S5, during the closed stirring, the temperature is 20°C to 40°C, and the time is 2h to 10h; during the heating to evaporate ammonia, the temperature is 50°C to 100°C, and the time is 1h to 6h, and the pH value of the mixed gel solution C is 5 to 8.

[0019] In the above steps S6 and S7, during the first calcination and the second calcination, the calcination temperature is 530° C. to 600° C., and the calcination time is 3 h to 10 h.

[0020] In the above step S7, the concentration of the ammonium salt solution is 1 mol / L to 5 mol / L, the ammonium salt is one of ammonium chloride and ammonium nitrate, the ammonium exchange temperature is 30°C to 60°C, the ammonium exchange time is 3h to 12h, and the number of immersions is 1 to 2 times.

[0021] In the above step S6, the crystallization reaction temperature is 100° C. to 220° C., and the reaction time is 24 h to 96 h.

[0022] In the above step S6, the crystallization reaction temperature is 140° C. to 180° C., and the reaction time is 48 h to 72 h.

[0023] In the above steps S6 and S7, during the primary calcination and the secondary calcination, the heating rate is controlled to be 1°C / min to 5°C / min, the drying time is 50°C to 180°C, and the drying temperature is 1h to 24h.

[0024] In the above steps S6 and S7, during the first calcination and the second calcination, the heating rate is controlled to be 2°C / min to 3°C / min, the drying time is 90°C to 150°C, and the drying temperature is 3h to 12h.

[0025] In the above step S3, the stirring temperature is 10°C to 50°C, and the stirring time is 2h to 10h.

[0026] In the above step S3, the stirring temperature is 20° C. to 30° C., and the stirring time is 2 h to 5 h.

[0027] The second technical solution of the present invention is achieved by the following measures: A method for preparing a nickel-based molecular sieve catalyst prepared by an ammonia evaporation / in-situ synthesis method is carried out as follows: S1, add silicon source and alkali source to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source, ZSM-5 seed crystal and template agent to deionized water in sequence and stirring evenly to form solution b; S3, slowly adding solution b to solution a, stirring vigorously to mix evenly, to form gel solution A; S4, dissolving the nickel salt in deionized water to obtain a nickel salt aqueous solution, and adjusting the pH of the nickel salt aqueous solution with ammonia water to obtain a nickel ammonia solution B; S5, adding the nickel ammonia solution B to the gel solution A in a sealed state with stirring, and then heating to evaporate ammonia to obtain a mixed gel solution C; S6, subjecting the mixed gel solution C to a crystallization reaction, filtering the obtained reaction product, washing it to neutrality, and then drying and calcining it once to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt solution for ammonium exchange, filtering and washing the impregnated catalyst precursor until the pH is 5 to 8, and then drying and calcining the catalyst precursor twice to obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0028] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained by the preparation method of the present invention has high dispersion of the active ingredient nickel in the molecular sieve, which increases the active surface area, is relatively evenly dispersed, and will not block the internal pores of the molecular sieve, thereby greatly improving the activity of the catalyst. The catalyst is applied to a methanol-coupled light hydrocarbon to olefin reaction system to increase the yield of the product olefins, increase the stability, and the performance of the regenerated catalyst is equivalent to that of the fresh catalyst. At the same time, the preparation cost is low, the preparation process is simple, and the problems of easy carbon deposition and deactivation, low product yield, and poor catalyst regeneration performance existing in the existing metal-loaded molecular sieve catalyst can be effectively solved. DETAILED DESCRIPTION

[0029] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all chemical reagents and chemicals known and used in the prior art; unless otherwise specified, the percentages in the present invention are all mass percentages; unless otherwise specified, the solutions in the present invention are all aqueous solutions in which the solvent is water, for example, the hydrochloric acid solution is an aqueous hydrochloric acid solution.

[0030] The present invention will be further described below in conjunction with embodiments: Example 1: The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method is obtained by the following method: S1, add silicon source and alkali source to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source, ZSM-5 seed crystal and template agent to deionized water in sequence and stirring evenly to form solution b; S3, adding solution b dropwise into solution a, stirring and mixing evenly to form gel solution A; S4, dissolving the nickel salt in deionized water to obtain a nickel salt aqueous solution, and adjusting the pH of the nickel salt aqueous solution with ammonia water to obtain a nickel ammonia solution B; S5, adding the nickel ammonia solution B to the gel solution A in a sealed state with stirring, and then heating to evaporate ammonia to obtain a mixed gel solution C; S6, subjecting the mixed gel solution C to a crystallization reaction, filtering the obtained reaction product, washing it to neutrality, and then drying and calcining it once to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt solution for ammonium exchange, filtering and washing the impregnated catalyst precursor until the pH is 5 to 8, and then drying and calcining the catalyst precursor twice to obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0031] Compared with the prior art, the nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained by the preparation method of the present invention can load the active ingredient metal nickel in the molecular sieve while synthesizing the molecular sieve in situ, and can effectively adjust the size of the nickel grains, reduce the size of the nickel grains, make the nickel grains highly dispersed inside the molecular sieve, strengthen the interaction between the metal and the carrier, and thus improve the stability of the catalyst.

[0032] Example 2: As an optimization of the above example, the molar ratio of the silicon source (in terms of SiO2), the alkali source (in terms of Na2O), the aluminum source (in terms of Al2O3), the template and deionized water is (30 to 290): (0.4 to 28): 1: (5.5 to 31): (2500 to 6500).

[0033] Example 3: As an optimization of the above example, the mass ratio of ZSM-5 seed crystals to template is 1:(0.5 to 5.0).

[0034] Embodiment 4: As an optimization of the above embodiment, the silicon source is one or more of silica sol, silica gel, tetraethyl orthosilicate, sodium silicate nonahydrate and fumed silica.

[0035] Embodiment 5: As an optimization of the above embodiment, the alkali source is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide.

[0036] Example 6: As an optimization of the above example, the aluminum source is one or more of aluminum sulfate, sodium aluminate, aluminum chloride, aluminum nitrate, aluminum isopropoxide and aluminum oxide.

[0037] Example 7: As an optimization of the above example, the template agent is one or more of n-butylamine, ethylenediamine, tetrabutylammonium hydroxide and hexadecyltrimethylammonium bromide.

[0038] Example 8: As an optimization of the above example, the molar ratio of silicon to aluminum in the ZSM-5 seed crystal is 30, 150 or 300.

[0039] Example 9: As an optimization of the above example, the nickel salt is one of Ni(NO3)2·6H2O and NiSO4·6H2O.

[0040] Example 10: As an optimization of the above example, in step S4, the pH value of the nickel salt aqueous solution is adjusted to 9 to 12 with ammonia water having a mass concentration of 20% to 30%, to obtain a nickel ammonia solution B with a nickel concentration of 0.1 mol / L to 4.0 mol / L.

[0041] Example 11: As an optimization of the above example, in step S5, during closed stirring, the temperature is 20°C to 40°C, and the time is 2h to 10h; during heating to evaporate ammonia, the temperature is 50°C to 100°C, and the time is 1h to 6h, and the pH value of the mixed gel solution C is 5 to 8.

[0042] Example 12: As an optimization of the above example, in steps S6 and S7, during the first and second calcinations, the calcination temperatures are both 530°C to 600°C, and the calcination times are both 3h to 10h.

[0043] Example 13: As an optimization of the above example, in step S7, the concentration of the ammonium salt solution is 1 mol / L to 5 mol / L, the ammonium salt is one of ammonium chloride and ammonium nitrate, the ammonium exchange temperature is 30°C to 60°C, the ammonium exchange time is 3h to 12h, and the number of immersions is 1 to 2 times.

[0044] Example 14: As an optimization of the above example, in step S6, the crystallization reaction temperature is 100°C to 220°C, and the reaction time is 24h to 96h.

[0045] Example 15: As an optimization of the above example, in step S6, the crystallization reaction temperature is 140°C to 180°C, and the reaction time is 48h to 72h.

[0046] Example 16: As an optimization of the above example, in steps S6 and S7, during the first and second roasting, the heating rate is controlled to be 1°C / min to 5°C / min, the drying time is 50°C to 180°C, and the drying temperature is 1h to 24h.

[0047] Example 17: As an optimization of the above example, in steps S6 and S7, during the first and second roasting, the heating rate is controlled to be 2°C / min to 3°C / min, the drying time is 90°C to 150°C, and the drying temperature is 3h to 12h.

[0048] Example 18: As an optimization of the above example, in step S3, the stirring temperature is 10°C to 50°C, and the stirring time is 2h to 10h.

[0049] Example 19: As an optimization of the above example, in step S3, the stirring temperature is 20°C to 30°C, and the stirring time is 2h to 5h.

[0050] Embodiment 20: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add silicon source (silica sol) and alkali source (sodium hydroxide) to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source (aluminum sulfate), ZSM-5 seed crystals (silicon-aluminum ratio of 30) and template (n-butylamine) to deionized water in sequence, stirring evenly to form solution b; S3, slowly drop solution b into solution a, vigorously stir at 10°C for 2h to mix evenly, to form gel solution A; wherein the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 30:0.4:1:5.5:2500, and the mass ratio of ZSM-5 seed crystal to template is 1:0.5; S4, dissolving nickel salt (Ni(NO3)2·6H2O) in deionized water to obtain a nickel salt aqueous solution, adjusting the pH of the nickel salt aqueous solution to 9 with 20% ammonia water to obtain a nickel ammonia solution B with a nickel concentration of 0.1 mol / L; S5, adding nickel ammonia solution B to gel solution A, stirring in a sealed container at 20°C for 2 hours, and then heating at 50°C for 1 hour to evaporate ammonia until the pH value of the solution is 5, thereby obtaining a mixed gel solution C; S6, crystallizing the mixed gel solution C at 100° C. for 24 hours, filtering and washing the obtained reaction product to neutrality, then drying at 50° C. for 1 hour, and finally calcining at 530° C. at a heating rate of 1° C. / min for 3 hours to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt (ammonium chloride) solution with a concentration of 1 mol / L at 30°C for ammonium exchange for 3 to 12 hours, repeating the immersion once, filtering and washing the impregnated catalyst precursor to a pH of 5, then drying at 50°C for 1 hour, and finally calcining it for a second time at 530°C with a heating rate of 1°C / min for 3 hours to obtain a nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method.

[0051] Embodiment 21: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add silicon source (silica gel) and alkali source (potassium hydroxide) to deionized water in sequence and stir evenly to form solution a; S2, adding an aluminum source (sodium aluminate), a ZSM-5 seed crystal (silicon-aluminum ratio of 150) and a template (ethylenediamine) to deionized water in sequence, stirring evenly to form a solution b; S3, slowly drop solution b into solution a, vigorously stir at 50°C for 10 h to mix evenly, to form gel solution A; wherein the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 290:28:1:31:6500, and the mass ratio of ZSM-5 seed crystal to template is 1:5.0; S4, dissolving nickel salt (NiSO4·6H2O) in deionized water to obtain a nickel salt aqueous solution, adjusting the pH of the nickel salt aqueous solution to 12 with 30% ammonia water to obtain a nickel ammonia solution B with a nickel concentration of 4.0 mol / L; S5, adding nickel ammonia solution B to gel solution A, stirring in a sealed container at 40° C. for 10 h, and then heating at 100° C. to evaporate ammonia for 6 h until the pH value of the mixed solution reaches 8, thereby obtaining a mixed gel solution C; S6, crystallizing the mixed gel solution C at 220°C for 96 hours, filtering and washing the obtained reaction product to neutrality, then drying at 180°C for 24 hours, and finally calcining at 600°C at a heating rate of 5°C / min for 10 hours to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt (ammonium nitrate) solution with a concentration of 5 mol / L at 60°C for ammonium exchange for 12 hours, repeating the immersion twice, filtering and washing the impregnated catalyst precursor until the pH is 8, then drying at 180°C for 24 hours, and finally calcining it for a second time at 600°C and a heating rate of 5°C / min for 10 hours to obtain a nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method.

[0052] Embodiment 22: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add silicon source (tetraethyl orthosilicate) and alkali source (calcium hydroxide) to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source (aluminum chloride), ZSM-5 seed crystals (silicon-aluminum ratio of 300) and template (tetrabutylammonium hydroxide) to deionized water in sequence, stirring evenly to form solution b; S3, slowly drop solution b into solution a, vigorously stir at 50°C for 10 h to mix evenly, to form gel solution A; wherein the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 200:15:1:20:5000, and the mass ratio of ZSM-5 seed crystal to template is 1:3; S4, dissolving nickel salt (Ni(NO3)2·6H2O) in deionized water to obtain a nickel salt aqueous solution, adjusting the pH of the nickel salt aqueous solution to 11 with 25% ammonia water to obtain a nickel ammonia solution B with a nickel concentration of 2 mol / L; S5, adding nickel ammonia solution B to gel solution A, stirring in a sealed container at 30° C. for 6 h, and then heating at 70° C. to evaporate ammonia for 3 h until the pH value of the mixed solution is 7, thereby obtaining a mixed gel solution C; S6, crystallizing the mixed gel solution C at 150° C. for 50 h, filtering and washing the obtained reaction product to neutrality, then drying at 100° C. for 15 h, and finally calcining at 570° C. at a heating rate of 3° C. / min for 6 h to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt (ammonium chloride) solution with a concentration of 3 mol / L at 45°C for ammonium exchange for 9 hours, repeating the immersion twice, filtering and washing the impregnated catalyst precursor to a pH of 5 to 8, then drying at 100°C for 15 hours, and finally calcining it for a second time at 570°C with a heating rate of 3°C / min for 6 hours to obtain a nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method.

[0053] Embodiment 23: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 190g of ethyl orthosilicate and 12ml of 7mol / L NaOH to 300g of deionized water, and stir evenly at room temperature to form solution a; S2, add 0.987 g of sodium aluminate, 10 g of ZSM-5 seed crystals and 11.74 g of tetrabutylammonium hydroxide to 100 g of deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 5 h at 30 °C to mix well, to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 152:8:1:7.53:3703); S4, taking 0.5 g Ni(NO3)2·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; S5, adding nickel ammonia solution B to gel solution A at 30°C, sealing and stirring for 8 hours, and then heating and evaporating ammonia at 70°C and stirring for 6 hours until the solution pH is 6, to obtain a mixed gel solution C; S6, transferring the mixed gel solution C to a stainless steel hydrothermal synthesis reactor, heating at 160°C for 48 hours for crystallization reaction, filtering and washing the mixed solution in the reactor until it is neutral, drying at 100°C for 8 hours, and finally calcining at 550°C for 2 hours to obtain a catalyst precursor; S7, weigh 19g of catalyst precursor and add it to 500mL of 1 mol / L NH4Cl solution, stir it in a 60℃ water bath for 2h, then add deionized water to filter and wash until the pH is 6 to 7. Put the filtered filter cake into the above NH4Cl solution again, and repeat the above steps once. Then, dry it in an oven at 100℃ for 8h, put it in a muffle furnace for secondary calcination at 550℃ for 2h, and obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0054] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 23 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 23 of the present invention and the 75wt% Al2O3 carrier are tableted or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 3:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 500 °C, a pressure of 1.5 MPa (N2), and a total mass space velocity WHSV of 0.5 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 48.9%, and the reaction time reached 960h when the methanol conversion rate was 100%.

[0055] Embodiment 24: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 500g of tetraethyl orthosilicate and 24ml of 18mol / L NaOH to 500g of deionized water, and stir evenly at room temperature to form solution a; S2, add 1.968g of sodium aluminate, 23.7g of ZSM-5 seed crystals and 15.8g of n-butylamine to 150g of deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 4 h at 25 °C to mix evenly to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 200:19:1:18:3009.26); S4, taking 1.02 g of Ni(NO3)2·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; Subsequent steps S5 to S7 are the same as those in Example 23 of the present invention.

[0056] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 24 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to produce light olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 24 of the present invention and the 75wt% Al2O3 carrier are tableted or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 480 °C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 57.8%, and the reaction time reached 1080h when the methanol conversion rate was 100%.

[0057] Embodiment 25: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 42.5g of fumed silica and 12ml of 2.5mol / L NaOH to 100g of deionized water, and stir evenly at room temperature to form solution a; S2, add 2.25g Al(NO3)3·9H2O, 4.25g ZSM-5 seed crystals and 3.606g ethylenediamine to 50g deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly add solution b to solution a, and stir vigorously at 30°C for 3 h to mix evenly to form gel solution A3 (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 235.8:5:1:10:2777.78) S4, taking 1.98 g of Ni(NO3)2·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; Subsequent steps S5, S6 and S7 are the same as those in Example 23 of the present invention.

[0058] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 25 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to produce light olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 25 of the present invention and the 75wt% Al2O3 carrier are tableted or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 480 °C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 45.42%, and the reaction time reached 950h when the methanol conversion rate was 100%.

[0059] Embodiment 26: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 430g of tetraethyl orthosilicate and 30ml of 8mol / L NaOH to 600g of deionized water, and stir evenly at room temperature to form solution a; S2, add 1.968g of sodium aluminate, 12.456g of ZSM-5 seed crystals and 62.28g of tetrabutylammonium hydroxide to 415g of deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 3 h at 30 °C to mix well, to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 172:22:1:20:4699.07); S4, taking 0.90 g NiSO4·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; S5, adding nickel ammonia solution B to gel solution A at 40°C, sealing and stirring for 4 hours, and then heating and evaporating ammonia at 90°C and stirring for 4 hours until the solution pH is 6, to obtain a mixed gel solution C; S6, transferring the mixed gel solution C to a stainless steel hydrothermal synthesis reactor, heating at 140°C for 72 hours for crystallization reaction, filtering and washing the mixed solution in the reactor until it is neutral, drying at 90°C for 12 hours, and finally calcining at 530°C for 4 hours to obtain a catalyst precursor; S7, weigh 19g of catalyst precursor and add it to 500mL of 1 mol / L NH4Cl solution, stir it in a 40℃ water bath for 4h, then add deionized water for filtration and washing until the pH is 6 to 7. Put the filtered filter cake into the above NH4Cl solution again, and repeat the above steps once. Then, dry it in an oven at 90℃ for 12h, put it in a muffle furnace for secondary calcination at 530℃ for 4h, and obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0060] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 26 of the present invention is applied to the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 26 of the present invention and the 75wt% Al2O3 carrier are pressed into tablets or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 480 °C, a pressure of 1.0 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 58.9%, and the reaction time reached 1104h when the methanol conversion rate was 100%.

[0061] Embodiment 27: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 52.325g of ethyl orthosilicate and 12ml of 7mol / L NaOH to 200g of deionized water, and stir evenly at room temperature to form solution a; S2, add 4g Al2(SO4)3•18H2O, 4.28g ZSM-5 seed crystals and 8.56g tetrabutylammonium hydroxide to 100g deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly add solution b to solution a, and stir vigorously at 20°C for 5 h to mix evenly to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 41.86:7:1:5.5:2777.78) S4, taking 1.98 g of Ni(NO3)2·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; Subsequent steps S5, S6 and S7 are the same as those in Example 23 of the present invention.

[0062] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 27 of the present invention is applied to the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 27 of the present invention and the 75wt% Al2O3 carrier are tableted or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 500 °C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 2.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 59.1%, and when the methanol conversion rate was above 95%, the reaction time reached 1224h.

[0063] Embodiment 28: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 51.12g of fumed silica and 17ml of 3mol / L NaOH to 300g of deionized water, and stir evenly at room temperature to form solution a; S2, add 2.26g Al(NO3)3·9H2O, 10g ZSM-5 seed crystals and 9.48g hexadecyltrimethylammonium bromide to 50g deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 2 h at 30 °C to mix well, to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 283.62:8.5:1:8.67:6481.48); S4, taking 0.90 g NiSO4·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; S5, adding nickel ammonia solution B to gel solution A at 20°C, sealing and stirring for 10 hours, and then heating and evaporating ammonia at 50°C and stirring for 6 hours until the solution pH is 8, to obtain a mixed gel solution C; S6, transferring the mixed gel solution C to a stainless steel hydrothermal synthesis reactor, heating at 140°C for 72 hours for crystallization reaction, filtering and washing the mixed solution in the reactor until it is neutral, drying at 150°C for 4 hours, and finally calcining at 570°C for 4 hours to obtain a catalyst precursor; S7, weigh 19g of catalyst precursor and add it to 500mL of 1 mol / L NH4Cl solution, stir it in a 60℃ water bath for 2h, then add deionized water for filtration and washing until the pH is 6 to 7. Put the filtered filter cake into the above NH4Cl solution again, and repeat the above steps once. Then, dry it in an oven at 150℃ for 4h, put it in a muffle furnace for secondary calcination at 570℃ for 4h, and obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0064] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 28 of the present invention is applied to the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 28 of the present invention and the 75wt% Al2O3 carrier are pressed into tablets or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 480 °C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 56.7%, and the reaction time reached 1080h when the methanol conversion rate was 100%.

[0065] Embodiment 29: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 183g silica sol (SiO2 content 30%) and 12ml 8mol / L NaOH to 400g deionized water, stir evenly at room temperature to form solution a; S2, add 4.5g Al(NO3)3·9H2O, 30g ZSM-5 seed crystals and 10.98g ethylenediamine to 200g deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 5 h at 30 °C to mix well, to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 152.3:8:1:30.45:5555.56); S4, taking 1.8 g NiSO4·6H2O as nickel salt, adding 20 ml of deionized water, adding 20% ​​ammonia water dropwise into the nickel aqueous solution, adjusting the pH value of the nickel salt aqueous solution to 11, and preparing nickel ammonia solution B after stirring; S5, adding nickel ammonia solution B to gel solution A at 40°C, sealing and stirring for 4 hours, and then heating and evaporating ammonia at 100°C and stirring for 2 hours until the solution pH is 8, to obtain a mixed gel solution C; S6, transferring the mixed gel solution C to a stainless steel hydrothermal synthesis reactor, heating at 140°C for 72 hours for crystallization reaction, filtering and washing the mixed solution in the reactor until it is neutral, drying at 120°C for 6 hours, and finally calcining at 570°C for 4 hours to obtain a catalyst precursor; S7, weigh 19g of catalyst precursor and add it to 500mL of 1 mol / L NH4Cl solution, stir it in a 60℃ water bath for 2h, then add deionized water for filtration and washing until the pH is 6 to 7. Put the filtered cake into the above NH4Cl solution again, and repeat the above steps once. Then, dry it in an oven at 120℃ for 6h, put it in a muffle furnace for secondary calcination at 570℃ for 4h, and obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0066] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 29 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 29 of the present invention and the 75wt% Al2O3 carrier are tableted or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 3:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 500 °C, a pressure of 1.5 MPa (N2), and a total mass space velocity WHSV of 0.5 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 48.9%, and the reaction time reached 960h when the methanol conversion rate was 100%.

[0067] Embodiment 30: The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method is obtained by the following method: S1, add 183g silica sol (SiO2 content 30%) and 12ml 7mol / L NaOH to 170g deionized water in sequence, and stir evenly at room temperature to form solution a; S2, add 4 g Al2(SO4)3•18H2O, 10 g ZSM-5 seed crystals and 20 g hexadecyl ammonium bromide to 100 g deionized water in sequence, and stir evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 4 h at 25 °C to mix well, to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 152.3:7:1:9.15:2500); Subsequent steps S4 to S7 are the same as those in Example 28 of the present invention.

[0068] The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 30 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to produce low-carbon olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles prepared by the ammonia evaporation / in-situ synthesis method obtained in Example 30 of the present invention and the 75wt% Al2O3 carrier are pressed into tablets or extruded, crushed and sieved to screen out the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 420 °C, a pressure of 3.0 MPa (N2), and a total mass space velocity WHSV of 2.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 55.4%, and the reaction time reached 1124h when the methanol conversion rate was 100%.

[0069] Comparative Example 1: The nickel-based molecular sieve catalyst is obtained by the following method: S1, add 190g of ethyl orthosilicate and 12ml of 7mol / L NaOH to 300g of deionized water, and stir evenly at room temperature to form solution a; S2, 0.987 g of sodium aluminate, 0.5 g of Ni(NO3)2·6H2O, 10 g of ZSM-5 seed crystals and 11.74 g of tetrabutylammonium hydroxide were added to 100 g of deionized water in sequence, and stirred evenly at room temperature to form solution b; S3, slowly drop solution b into solution a, and vigorously stir for 3 h at 30 °C to mix evenly to form gel solution A (the molar ratio of silicon source (in terms of SiO2), alkali source (in terms of Na2O), aluminum source (in terms of Al2O3), template and deionized water in gel solution A is 152.3:8:1:0.28:7.54:3703); S4, transferring the gel solution A to a stainless steel hydrothermal synthesis reactor, heating at 150°C for crystallization reaction for 36 hours, filtering and washing the mixed solution in the reactor until it is neutral, drying at 120°C for 6 hours, and finally calcining at 550°C for 3 hours to obtain a catalyst precursor; S5, weigh 19g of catalyst precursor and add it to 500mL of 1 mol / L NH4Cl solution, stir it in a 60℃ water bath for 2h, then add deionized water for filtration and washing until the pH is 6 to 7. Put the filtered cake into the above NH4Cl solution again, and repeat the above steps once. Then, dry it in an oven at 120℃ for 6h, and then put it into a muffle furnace for secondary calcination at 550℃ for 4h to obtain a nickel-based molecular sieve catalyst.

[0070] The nickel-based molecular sieve catalyst obtained in Comparative Example 1 of the present invention is applied in the reaction of methanol coupling light hydrocarbons to prepare light olefins, and the specific steps are as follows: First, the nickel-based molecular sieve catalyst solid particles obtained in Comparative Example 1 of the present invention and 75wt% Al2O3 carrier are pressed into tablets or extruded, crushed and sieved to screen out catalysts with a particle size of 0.8 cm to 2.0 cm; Then, 50 g of catalyst particles were loaded into the middle of the reaction tube in the fixed bed reactor. The reaction materials methanol and hydrocracked light naphtha entered from the inlet of the fixed bed reactor at a mass ratio of 1:1 and contacted with the catalyst bed to undergo a coupled reforming reaction. The process conditions were a reaction temperature of 480 °C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; Finally, the results of methanol coupling light hydrocarbon reforming to enrich low-carbon olefins while taking into account the aromatics reaction were: the yield of ethylene + propylene + butene was 25.6%, and the reaction time reached 144h when the methanol conversion rate was 100%.

[0071] Embodiment 31: The catalytic performance of the nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method of the present invention after being regenerated after being deactivated by the reaction was investigated.

[0072] (1) The specific steps of the catalyst regeneration process are as follows: First, the nickel-based molecular sieve catalysts prepared by the ammonia evaporation / in-situ synthesis method of Example 24 and Example 26 of the present invention and the nickel-based molecular sieve catalyst of Comparative Example 1, which were deactivated after being applied to the methanol coupling reaction of light hydrocarbons to produce low-carbon olefins, were unloaded from the fixed bed reactor, and the porcelain ball powder was filtered out to leave the catalyst with a particle size of 0.8 cm to 2.0 cm; Then, the deactivated nickel-based molecular sieve catalyst particles prepared by ammonia evaporation / in-situ synthesis method were placed in a fixed bed reactor and regenerated by N2 at a regeneration temperature of 530°C and a regeneration time of 4 hours to obtain a regenerated nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

[0073] (2) The regenerated catalyst is used again in the methanol coupling reaction of light hydrocarbons to produce low-carbon olefins. The specific steps are as follows: 50 g of nickel-based molecular sieve catalyst particles prepared by ammonia evaporation / in-situ synthesis method after regeneration in Example 24 and Example 26 of the present invention and the nickel-based molecular sieve catalyst particles after regeneration in Comparative Example 1 were respectively loaded into the middle of the reaction tube in the fixed bed reactor, and the reaction materials methanol and hydrocracking light naphtha entered from the inlet of the fixed bed reactor in a mass ratio of 1:1, and contacted with the catalyst bed to undergo a coupled reforming reaction, wherein the process conditions were a reaction temperature of 500°C, a pressure of 0.5 MPa (N2), and a total mass space velocity WHSV of 1.0 h -1 After the reaction is completed, the reaction product is condensed and separated, and the sample is collected for chromatographic analysis; The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method after regeneration in Example 24 of the present invention was again applied to the methanol coupling light hydrocarbon reforming to enrich the low-carbon olefins and take into account the aromatics reaction. The yield of ethylene + propylene + butene was 55.4%, and the reaction time reached 960h when the methanol conversion rate was 100%; The nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method after regeneration in Example 26 of the present invention was again applied to the methanol coupling light hydrocarbon reforming to enrich the low-carbon olefins and take into account the aromatics reaction. The yield of ethylene + propylene + butene was 53.7%, and the reaction time reached 860h when the methanol conversion rate was 100%; The nickel-based molecular sieve catalyst regenerated in comparative example 1 of the present invention was again applied to methanol coupling light hydrocarbon reforming to enrich low-carbon olefins and take into account the reaction results of aromatic hydrocarbons: the yield of ethylene + propylene + butene was 39.8%, and when the methanol conversion rate was 100%, the reaction time reached 600h.

[0074] Compared with the nickel-based molecular sieve catalyst obtained in comparative example 1 of the present invention, the nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained in examples 23 and 30 of the present invention performs better in the coupling reforming reaction of methanol and light hydrocarbons, the reaction temperature is 400°C to 600°C, the yield of olefins (ethylene+propylene+butene) in the gas phase is 45% to 60%, and its stability can reach 850h to 1230h. After the reaction, the catalyst is regenerated and used for the coupling reforming reaction of methanol and light hydrocarbons, and its methanol conversion rate can still reach 100%, and the olefin yield is not reduced. The catalyst performance of the regenerated catalyst is equivalent to that of the fresh catalyst (the catalyst used for the first time).

[0075] In summary, the nickel-based molecular sieve catalyst prepared by the ammonia evaporation / in-situ synthesis method obtained by the preparation method of the present invention has a high dispersion of the active ingredient nickel in the molecular sieve, which increases the active surface area, and the nickel is dispersed more evenly, and will not block the internal pores of the molecular sieve, thereby greatly improving the activity of the catalyst. The catalyst is applied to a methanol-coupled light hydrocarbon to olefin reaction system, so that the product olefin yield is increased, the stability is increased, and the performance of the regenerated catalyst is equivalent to that of the fresh catalyst. At the same time, the preparation cost is low, the preparation process is simple, and the problems of easy carbon deposition and deactivation, low product yield, and poor catalyst regeneration performance existing in the existing metal-loaded molecular sieve catalyst can be effectively solved.

[0076] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A nickel-based molecular sieve catalyst prepared by an ammonia evaporation / in-situ synthesis method, characterized in that Obtained as follows: S1, add silicon source and alkali source to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source, ZSM-5 seed crystal and template agent to deionized water in sequence and stirring evenly to form solution b; S3, adding solution b dropwise into solution a, stirring and mixing evenly to form gel solution A; S4, dissolving the nickel salt in deionized water to obtain a nickel salt aqueous solution, and adjusting the pH of the nickel salt aqueous solution with ammonia water to obtain a nickel ammonia solution B; S5, adding the nickel ammonia solution B to the gel solution A in a sealed state with stirring, and then heating to evaporate ammonia to obtain a mixed gel solution C; S6, subjecting the mixed gel solution C to a crystallization reaction, filtering the obtained reaction product, washing it to neutrality, and then drying and calcining it once to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt solution for ammonium exchange, filtering and washing the impregnated catalyst precursor until the pH is 5 to 8, and then drying and calcining the catalyst precursor twice to obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.

2. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to claim 1, characterized in that The molar ratio of silicon source, alkali source, aluminum source, template and deionized water is 30 to 290: 0.4 to 28: 1: 5.5 to 31: 2500 to 6500; or / and, the mass ratio of ZSM-5 seed crystal to template is 1: 0.5 to 5.

0.

3. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to claim 1 or 2, characterized in that The silicon source is one or more of silica sol, silica gel, tetraethyl orthosilicate, sodium silicate nonahydrate and fumed silica; or / and, the alkali source is one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide; or / and, the aluminum source is one or more of aluminum sulfate, sodium aluminate, aluminum chloride, aluminum nitrate, aluminum isopropoxide and aluminum oxide.

4. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to claim 1, 2 or 3, characterized in that The template agent is one or more of n-butylamine, ethylenediamine, tetrabutylammonium hydroxide and hexadecyltrimethylammonium bromide; or / and, the molar ratio of silicon to aluminum in the ZSM-5 seed crystal is 30, 150 or 300; or / and, the nickel salt is one of Ni(NO3)2·6H2O and NiSO4·6H2O.

5. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to any one of claims 1 to 4, characterized in that In step S4, the pH value of the nickel salt aqueous solution is adjusted to 9 to 12 with ammonia water having a mass concentration of 20% to 30%, to obtain a nickel ammonia solution B having a nickel concentration of 0.1 mol / L to 4.0 mol / L; or / and, in step S5, during closed stirring, the temperature is 20°C to 40°C, and the time is 2h to 10h; during heating to evaporate ammonia, the temperature is 50°C to 100°C, and the time is 1h to 6h, and the pH value of the mixed gel solution C is 5 to 8.

6. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to any one of claims 1 to 5, characterized in that In steps S6 and S7, during the first and second roasting, the roasting temperature is 530° C. to 600° C., and the roasting time is 3 h to 10 h; or / and, in step S7, the concentration of the ammonium salt solution is 1 mol / L to 5 mol / L, the ammonium salt is one of ammonium chloride and ammonium nitrate, the ammonium exchange temperature is 30° C. to 60° C., the ammonium exchange time is 3 h to 12 h, and the number of immersions is 1 to 2 times.

7. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to any one of claims 1 to 6, characterized in that In step S6, the crystallization reaction temperature is 100°C to 220°C, and the reaction time is 24h to 96h; or / and, in steps S6 and S7, during the first calcination and the second calcination, the heating rate is controlled to be 1°C / min to 5°C / min, the drying time is 50°C to 180°C, and the drying temperature is 1h to 24h; or / and, in step S3, the stirring temperature is 10°C to 50°C, and the stirring time is 2h to 10h.

8. The nickel-based molecular sieve catalyst prepared by the ammonia distillation / in-situ synthesis method according to claim 7, characterized in that In step S6, the crystallization reaction temperature is 140°C to 180°C, and the reaction time is 48h to 72h; or / and, in steps S6 and S7, during the first calcination and the second calcination, the heating rate is controlled to be 2°C / min to 3°C / min, the drying time is 90°C to 150°C, and the drying temperature is 3h to 12h; or / and, in step S3, the stirring temperature is 20°C to 30°C, and the stirring time is 2h to 5h.

9. A method for preparing a nickel-based molecular sieve catalyst prepared by ammonia distillation / in-situ synthesis method according to any one of claims 2 to 8, characterized in that Proceed as follows: S1, add silicon source and alkali source to deionized water in sequence and stir evenly to form solution a; S2, adding aluminum source, ZSM-5 seed crystal and template agent to deionized water in sequence and stirring evenly to form solution b; S3, slowly adding solution b to solution a, stirring vigorously to mix evenly, to form gel solution A; S4, dissolving the nickel salt in deionized water to obtain a nickel salt aqueous solution, and adjusting the pH of the nickel salt aqueous solution with ammonia water to obtain a nickel ammonia solution B; S5, adding the nickel ammonia solution B to the gel solution A in a sealed state with stirring, and then heating to evaporate ammonia to obtain a mixed gel solution C; S6, subjecting the mixed gel solution C to a crystallization reaction, filtering the obtained reaction product, washing it to neutrality, and then drying and calcining it once to obtain a catalyst precursor; S7, immersing the obtained catalyst precursor in an ammonium salt solution for ammonium exchange, filtering and washing the impregnated catalyst precursor until the pH is 5 to 8, and then drying and calcining the catalyst precursor twice to obtain a nickel-based molecular sieve catalyst prepared by ammonia evaporation / in-situ synthesis method.