Catalyst for preparing low-carbon olefin from low-carbon alcohol as well as preparation method and application of catalyst

Abstract

The invention discloses a catalyst for preparing low-carbon olefin from low-carbon alcohol and a preparation method and application of the catalyst, and belongs to the technical field of preparation of low-carbon olefin from low-carbon alcohol, the catalyst comprises the following components in percentage by weight: 64-73% of modified ZMQ-1 molecular sieve, 15-22% of composite molecular sieve and the balance of modified silicoaluminophosphate molecular sieve; the modified silicoaluminophosphate molecular sieve, the composite molecular sieve and the modified ZMQ-1 molecular sieve are sequentially filled in a layered manner to form the catalyst for preparing the low-carbon olefin from the low-carbon alcohol; the composite molecular sieve is prepared from a modified silicoaluminophosphate molecular sieve and a modified ZMQ-1 molecular sieve; the modification method of the ZMQ-1 molecular sieve comprises the following steps: treating the ZMQ-1 molecular sieve with an acetic acid solution, mixing the treated ZMQ-1 molecular sieve with a solution containing iron ions or calcium ions, and introducing the iron ions and the calcium ions into pores of the molecular sieve by adopting an impregnation-pyrolysis method. The catalyst is high in propylene selectivity and total olefin selectivity, the reaction time for reducing the conversion rate to 95% is long, precious metal elements are not used for doping modification in the preparation process, and industrial production can be achieved easily.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing light olefins from light alcohols, and specifically relates to a catalyst for preparing light olefins from light alcohols, a preparation method thereof and an application thereof. Background Art

[0002] Light olefins are important chemical raw materials. Among them, ethylene and propylene can be used to synthesize polymer products such as polyethylene and polypropylene and other organic synthesis intermediates respectively, and butene can be further synthesized into different types of synthetic rubbers through butadiene intermediates.

[0003] Preparing light olefins from light alcohols is an important method for preparing light olefins, and the use of molecular sieve catalysts is widely applied in the industry. Doping with metal elements is an important method for regulating the catalytic performance of molecular sieve catalysts. Different types and introduction methods of metal elements will also lead to different catalytic performances of the catalysts. At present, in order to improve the performance of molecular sieves, a modification route of doping with noble metal elements is mostly used. The cost of noble metals is high, which increases the preparation cost and is difficult to industrialize on a large scale.

[0004] Based on this, the present invention designs a catalyst for preparing light olefins from light alcohols, a preparation method thereof and an application thereof to solve the above problems. Summary of the Invention

[0005] Aiming at the above-mentioned disadvantages of the prior art, the present invention provides a catalyst for preparing light olefins from light alcohols, a preparation method thereof and an application thereof.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] A catalyst for preparing light olefins from light alcohols, calculated by weight percentage, comprises 64-73% of modified ZMQ-1 molecular sieve, 15-22% of composite molecular sieve and the balance of modified silicoaluminophosphate molecular sieve;

[0008] The modified silicoaluminophosphate molecular sieve, the composite molecular sieve and the modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for preparing light olefins from light alcohols; the composite molecular sieve is prepared from the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve according to a mass ratio of 1:3-5;

[0009] The modification method of the ZMQ-1 molecular sieve is: after treating the ZMQ-1 molecular sieve with an acetic acid solution, mixing it with a solution containing iron ions or calcium ions, and introducing the iron ions and calcium ions into the pores of the molecular sieve by an impregnation-pyrolysis method.

[0010] Furthermore, the ZMQ-1 molecular sieve is prepared by the method disclosed in the invention patent CN118515294A.

[0011] Furthermore, first place the ZMQ-1 molecular sieve into an acetic acid solution with a volume 2 - 3 times that of the molecular sieve and a concentration of 5 - 15 wt%, soak it at 30 - 35 °C for 2 - 3 h, collect the ZMQ-1 molecular sieve by centrifugation, wash and dry it, then calcine and activate it at 510 - 545 °C for 2 - 3 h, and reserve the acidic washing water A for reuse; weigh Fe(NO3)3·9H2O and Ca(NO3)2·4H2O respectively, dissolve them in the acidic washing water A to prepare a ferric nitrate solution with a concentration of 0.4 - 0.7 mol / L and a calcium nitrate solution with a concentration of 0.1 - 0.3 mol / L, mix the two solutions according to a volume ratio of 2:1 - 1.2 and stir evenly to obtain a mixed solution, and transfer it to a three-necked flask; add the ZMQ-1 molecular sieve to the three-necked flask, and use a magnetic stirrer to stir the ZMQ-1 molecular sieve and the above mixed solution at 50 - 60 °C for 5 - 10 h; collect the solid by centrifugation and dry it at 125 - 155 °C to remove most of the solvent, and then calcine it at 550 - 600 °C for 3 - 4 h.

[0012] Furthermore, the mass ratio of the ZMQ-1 molecular sieve to the mixed solution is 1:8 - 12.

[0013] Furthermore, the modification method of the silicoaluminophosphate molecular sieve is as follows: put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment at 500 - 600 °C, introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace, take it out of the atmosphere furnace and cool it after treatment for 3 - 5 min, put the SAPO-5 silicoaluminophosphate molecular sieve into a quaternary ammonium hydroxide solution with a low temperature of 3 - 5 °C and a concentration of 0.3 - 1.6 mol / L for treatment for 10 - 15 min, and the mass ratio of the SAPO-5 silicoaluminophosphate molecular sieve to the quaternary ammonium hydroxide solution is 1:3 - 5; collect the solid by centrifugation and dry it at 115 - 135 °C, and then calcine it at 465 - 515 °C for 2 - 4 h.

[0014] Furthermore, the nitrogen flow rate is 0.05 - 0.1 m 3 / h, and the water vapor flow rate is 0.02 - 0.04 m 3 / h.

[0015] Furthermore, the preparation method of the composite molecular sieve is as follows: grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve to 5 - 10 microns, add silica sol accounting for 20 - 25% of the total amount of the molecular sieve, carry out tabletting, dry it, and then calcine it at 550 - 600 °C for 3 - 4 h.

[0016] To better achieve the object of the present invention, the present invention also provides a preparation method of a catalyst for preparing light olefins from light alcohols, and the steps are as follows:

[0017] 1. Preparation of modified ZMQ-1 molecular sieve

[0018] After treating ZMQ-1 molecular sieve with acetic acid solution, it is mixed with a solution containing iron ions or calcium ions, and iron ions and calcium ions are introduced into the pores of the molecular sieve by the impregnation-pyrolysis method;

[0019] II. Preparation of modified silicoaluminophosphate molecular sieve

[0020] Put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace. After treating for 3 - 5 min, take it out of the atmosphere furnace and cool it. Then put the SAPO-5 silicoaluminophosphate molecular sieve into a quaternary ammonium hydroxide solution with a low temperature of 3 - 5 °C and a concentration of 0.3 - 1.6 mol / L for 10 - 15 min; After centrifugation, collect the solid and dry it, and then calcine it at 465 - 515 °C for 2 - 4 h;

[0021] III. Preparation of composite molecular sieve

[0022] Grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve, add 20 - 25% of silica sol based on the total amount of the molecular sieve, carry out tableting, dry it, and then calcine it at 550 - 600 °C for 3 - 4 h;

[0023] IV. The modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for the production of light olefins from light alcohols.

[0024] To better achieve the purpose of the present invention, the present invention also provides a catalyst for the production of light olefins from light alcohols obtained according to the above preparation method.

[0025] To better achieve the purpose of the present invention, the present invention also provides an application of the catalyst in the production of light olefins from light alcohols.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: The propylene selectivity of the catalyst of the present invention is high (greater than 58%), the total olefin selectivity is high (greater than 89%), and the reaction time for the conversion rate to drop to 95% is long (greater than 1000 h). Compared with the catalyst of Comparative Example 1, the catalyst prepared in the examples of the present invention has the advantages of good stability and high catalytic activity. Moreover, the present invention uses the modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve to be loaded in layers in sequence to form a catalyst for the production of light olefins from light alcohols. During the preparation process, no precious metal element doping modification is used, which is conducive to industrial production. Specific embodiments

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0028] Example 1: In some embodiments, a catalyst for producing light olefins from light alcohols, calculated by weight percentage, comprises 64% of modified ZMQ-1 molecular sieve, 15% of composite molecular sieve, and the balance of modified silicoaluminophosphate molecular sieve; the modified silicoaluminophosphate molecular sieve, composite molecular sieve, and modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for producing light olefins from light alcohols; the composite molecular sieve is prepared from the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve according to a mass ratio of 1:3;

[0029] The ZMQ-1 molecular sieve is prepared by the method disclosed in the invention patent CN118515294A;

[0030] The modification method of the ZMQ-1 molecular sieve is as follows: after treating the ZMQ-1 molecular sieve with an acetic acid solution, it is mixed with a solution containing iron ions or calcium ions, and iron ions and calcium ions are introduced into the pores of the molecular sieve by the impregnation-pyrolysis method; specifically, first put the ZMQ-1 molecular sieve into 2 times the volume of 15wt% acetic acid solution, soak it at 30°C for 3h, after centrifugation, collect the ZMQ-1 molecular sieve, wash and dry it, then calcine and activate it at 510°C for 3h, and recover and reserve the acidic washing water A; weigh Fe(NO3)3·9H2O and Ca(NO3)2·4H2O and dissolve them in the acidic washing water A respectively to prepare a 0.4mol / L iron nitrate solution and a 0.3mol / L calcium nitrate solution, mix the two according to a volume ratio of 2:1 and stir evenly to obtain a mixed solution, and transfer it to a three-necked flask; add the ZMQ-1 molecular sieve to the three-necked flask, and use a magnetic stirrer to stir the ZMQ-1 molecular sieve and the above mixed solution at 60°C for 5h, and the mass ratio of the ZMQ-1 molecular sieve to the mixed solution is 1:12; after centrifugation, collect the solid and dry it at 125°C to remove most of the solvent, and then calcine it at 600°C for 3h;

[0031] The modification method of the silicoaluminophosphate molecular sieve is as follows: put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment at 500°C, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace, with a nitrogen flow rate of 0.1m 3 / h and a water vapor flow rate of 0.02m 3 / h, after treatment for 5 min, take it out from the atmosphere furnace and cool it. Put the SAPO-5 silicoaluminophosphate molecular sieve into a 1.6 mol / L quaternary ammonium hydroxide solution at a low temperature of 3°C and treat it for 10 min. The mass ratio of the SAPO-5 silicoaluminophosphate molecular sieve to the quaternary ammonium hydroxide solution is 1:5; after centrifugation, collect the solid and dry it at 115°C, and then calcine it at 515°C for 2 h;

[0032] The preparation method of the composite molecular sieve is as follows: Grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve to 5 microns, add 25% of silica sol based on the total amount of the molecular sieve, carry out tabletting, and after drying, calcine it at 550°C for 4 h.

[0033] Example 2: In some embodiments, a catalyst for producing light olefins from light alcohols, in terms of weight percentage, comprises 73% of modified ZMQ-1 molecular sieve, 22% of composite molecular sieve and the balance of modified silicoaluminophosphate molecular sieve; the modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for producing light olefins from light alcohols; the composite molecular sieve is prepared from the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve according to a mass ratio of 1:5;

[0034] The ZMQ-1 molecular sieve is prepared by the method disclosed in the invention patent CN118515294A;

[0035] The modification method of the ZMQ-1 molecular sieve is as follows: After treating the ZMQ-1 molecular sieve with acetic acid solution, mix it with a solution containing iron ions or calcium ions, and introduce iron ions and calcium ions into the pores of the molecular sieve by the impregnation-pyrolysis method; specifically, first put the ZMQ-1 molecular sieve into 3 times the volume of 5 wt% acetic acid solution, soak it at 35°C for 2 h, after centrifugation, collect the ZMQ-1 molecular sieve, wash and dry it, then calcine and activate it at 545°C for 2 h, and recycle the acidic washing water A for reuse; Weigh Fe(NO3)3·9H2O and Ca(NO3)2·4H2O and dissolve them in the acidic washing water A respectively to prepare a 0.7 mol / L iron nitrate solution and a 0.1 mol / L calcium nitrate solution. Mix the two according to a volume ratio of 2:1.2 and stir evenly to obtain a mixed solution, and transfer it to a three-necked flask; Add the ZMQ-1 molecular sieve to the three-necked flask, and stir the ZMQ-1 molecular sieve and the above mixed solution at 50°C for 10 h using a magnetic stirrer. The mass ratio of the ZMQ-1 molecular sieve to the mixed solution is 1:8; after centrifugation, collect the solid and dry it at 155°C to remove most of the solvent, and then calcine it at 550°C for 4 h;

[0036] The modification method of the silicoaluminophosphate molecular sieve is as follows: Take the SAPO-5 silicoaluminophosphate molecular sieve and put it into an atmosphere furnace for heat treatment at 600°C, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace. The nitrogen flow rate is 0.05 m3 / h, water vapor flow rate 0.04 m 3 / h. After treatment for 3 min, take it out from the atmosphere furnace and cool it. Put the SAPO-5 silicoaluminophosphate molecular sieve into a 0.3 mol / L quaternary ammonium hydroxide solution at 5 °C and treat it for 15 min. The mass ratio of the SAPO-5 silicoaluminophosphate molecular sieve to the quaternary ammonium hydroxide solution is 1:3; after centrifugation, collect the solid and dry it at 135 °C, and then calcine it at 465 °C for 4 h;

[0037] The preparation method of the composite molecular sieve is as follows: Grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve to 10 microns, add silica sol accounting for 20% of the total amount of the molecular sieve, carry out tabletting, and after drying, calcine it at 600 °C for 3 h.

[0038] Example 3: In some embodiments, a catalyst for preparing light olefins from light alcohols, in terms of weight percentage, comprises 68% of the modified ZMQ-1 molecular sieve, 20% of the composite molecular sieve, and the balance of the modified silicoaluminophosphate molecular sieve; the modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for preparing light olefins from light alcohols; the composite molecular sieve is prepared from the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve according to a mass ratio of 1:4;

[0039] The ZMQ-1 molecular sieve is prepared by the method disclosed in the invention patent CN118515294A;

[0040] The modification method of the ZMQ-1 molecular sieve is as follows: After treating the ZMQ-1 molecular sieve with an acetic acid solution, mix it with a solution containing iron ions or calcium ions, and introduce iron ions and calcium ions into the pores of the molecular sieve by the impregnation-pyrolysis method; specifically, first put the ZMQ-1 molecular sieve into 2.4 times the volume of a 10 wt% acetic acid solution, soak it at 32 °C for 2.5 h, after centrifugation, collect the ZMQ-1 molecular sieve, wash and dry it, then calcine it at 525 °C for 2.4 h for activation, and recycle the acidic washing water A for standby; weigh Fe(NO3)3·9H2O and Ca(NO3)2·4H2O and dissolve them in the acidic washing water A respectively to prepare a 0.48 mol / L iron nitrate solution and a 0.2 mol / L calcium nitrate solution, mix the two according to a volume ratio of 2:1.1 and stir evenly to obtain a mixed solution, and transfer it to a three-necked flask; add the ZMQ-1 molecular sieve to the three-necked flask, and stir the ZMQ-1 molecular sieve and the above mixed solution at 55 °C for 7 h by using a magnetic stirrer. The mass ratio of the ZMQ-1 molecular sieve to the mixed solution is 1:10; after centrifugation, collect the solid and dry it at 135 °C to remove most of the solvent, and then calcine it at 585 °C for 3.2 h;

[0041] The modification method of the silicoaluminophosphate molecular sieve is as follows: Put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment at 540 °C, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace. The nitrogen flow rate is 0.08 m 3 / h, and the water vapor flow rate is 0.03 m 3 / h. After treatment for 4 min, take it out of the atmosphere furnace and cool it. Put the SAPO-5 silicoaluminophosphate molecular sieve into a low-temperature 1 mol / L quaternary ammonium hydroxide solution at 4 °C for treatment for 13 min. The mass ratio of the SAPO-5 silicoaluminophosphate molecular sieve to the quaternary ammonium hydroxide solution is 1:4; after centrifugation, collect the solid and dry it at 125 °C, and then calcine it at 485 °C for 3 h;

[0042] The preparation method of the composite molecular sieve is as follows: Grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve to 8 microns, add silica sol accounting for 23% of the total amount of the molecular sieve, carry out tabletting, and after drying, calcine it at 580 °C for 3.2 h.

[0043] Comparative Example 1: The difference from Example 3 is that the composite molecular sieve is missing. A catalyst for producing light olefins from light alcohols, in terms of weight percentage, includes 68% of ZMQ-1 molecular sieve and the balance of silicoaluminophosphate molecular sieve; the silicoaluminophosphate molecular sieve and the ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for producing light olefins from light alcohols.

[0044] Experimental Example: Evaluate the catalysts prepared in Examples 1 to 3 and Comparative Example 1: Load 1 g of the catalyst into a fixed-bed reactor, the reaction temperature is 400 °C, at atmospheric pressure, and the space velocity is 1 h -1 , the methanol content is 85 wt%, and carry out the catalysis of methanol to propylene.

[0045] Table 1 Catalyst Evaluation Results

[0046]

[0047]

[0048] The results in Table 1 show that the catalyst has high propylene selectivity (greater than 58%), high total olefin selectivity (greater than 89%), and a long reaction time (greater than 1000 h) for the conversion rate to drop to 95%. Compared with the catalyst in Comparative Example 1, the catalyst prepared in the examples of the present invention has advantages such as good stability and high catalytic activity. Moreover, the present invention uses the modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve to be loaded in layers in sequence to form a catalyst for producing light olefins from light alcohols. During the preparation process, noble metal element doping modification is not used, which is beneficial to realizing industrial production.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A catalyst for producing light olefins from light alcohols, characterized in that, Comprising, by weight percentage, 64 - 73% of modified ZMQ-1 molecular sieve, 15 - 22% of composite molecular sieve, and the balance of modified silicoaluminophosphate molecular sieve; The modified silicoaluminophosphate molecular sieve, composite molecular sieve, and modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for producing light olefins from light alcohols; the composite molecular sieve is prepared from the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve according to a mass ratio of 1:3 - 5; The modification method of the ZMQ-1 molecular sieve is: after treating the ZMQ-1 molecular sieve with an acetic acid solution, mixing it with a solution containing iron ions or calcium ions, and introducing the iron ions and calcium ions into the pores of the molecular sieve by an impregnation-pyrolysis method.

2. The catalyst for preparing light olefins from light alcohols according to claim 1, wherein The ZMQ-1 molecular sieve is prepared by the method disclosed in the invention patent CN118515294A.

3. The catalyst for preparing light olefins from light alcohols according to claim 1, wherein First, put the ZMQ-1 molecular sieve into an acetic acid solution with a volume 2 - 3 times that of the ZMQ-1 molecular sieve, soak it at 30 - 35 °C for 2 - 3 h, after centrifugation, collect the ZMQ-1 molecular sieve, wash and dry it, then calcine and activate it at 510 - 545 °C for 2 - 3 h, and recover and reserve the acidic washing water A; weigh Fe(NO3)3·9H2O and Ca(NO3)2·4H2O respectively, dissolve them in the acidic washing water A to prepare a ferric nitrate solution with a concentration of 0.4 - 0.7 mol / L and a calcium nitrate solution with a concentration of 0.1 - 0.3 mol / L, mix the two according to a volume ratio of 2:1 - 1.2, stir evenly to obtain a mixed solution, and transfer it to a three-necked flask; add the ZMQ-1 molecular sieve to the three-necked flask, and use a magnetic stirrer to stir the ZMQ-1 molecular sieve and the above mixed solution at 50 - 60 °C for 5 - 10 h; after centrifugation, collect the solid and dry it at 125 - 155 °C to remove most of the solvent, and then calcine it at 550 - 600 °C for 3 - 4 h.

4. The catalyst for producing light olefins from light alcohols according to claim 3, wherein The mass ratio of the ZMQ-1 molecular sieve to the mixed solution is 1:8 - 12.

5. The catalyst for preparing light olefins from light alcohols according to any one of claims 1 to 4, characterized in that, The modification method of the silicoaluminophosphate molecular sieve is: put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment at 500 - 600 °C, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace. After treating for 3 - 5 min, take it out of the atmosphere furnace and cool it. Then put the SAPO-5 silicoaluminophosphate molecular sieve into a low-temperature 0.3 - 1.6 mol / L quaternary ammonium hydroxide solution at 3 - 5 °C for treatment for 10 - 15 min. The mass ratio of the SAPO-5 silicoaluminophosphate molecular sieve to the quaternary ammonium hydroxide solution is 1:3 - 5; after centrifugation, collect the solid and dry it at 115 - 135 °C, and then calcine it at 465 - 515 °C for 2 - 4 h.

6. The catalyst for producing light olefins from light alcohols according to claim 5, characterized in that, Nitrogen flow rate: 0.05 - 0.1 m 3 / h, steam flow rate: 0.02 - 0.04 m 3 / h.

7. The catalyst for producing light olefins from light alcohols according to claim 5, characterized in that, The preparation method of the composite molecular sieve is: grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve to 5 - 10 microns, add 20 - 25% of silica sol based on the total amount of the molecular sieve, carry out tabletting, dry it, and then calcine it at 550 - 600 °C for 3 - 4 h.

8. A method for preparing a catalyst for producing light olefins from light alcohols according to any one of claims 1 to 7, characterized in that, The steps are as follows: I. Prepare the modified ZMQ-1 molecular sieve After treating the ZMQ-1 molecular sieve with an acetic acid solution, mix it with a solution containing iron ions or calcium ions, and introduce the iron ions and calcium ions into the pores of the molecular sieve by an impregnation-pyrolysis method; II. Preparation of modified silicoaluminophosphate molecular sieve Put the SAPO-5 silicoaluminophosphate molecular sieve into an atmosphere furnace for heat treatment, and introduce a mixed carrier gas of nitrogen and water vapor into the atmosphere furnace. After treatment for 3 - 5 min, take it out of the atmosphere furnace and cool it. Then put the SAPO-5 silicoaluminophosphate molecular sieve into a quaternary ammonium hydroxide solution with a low temperature of 3 - 5 °C and a concentration of 0.3 - 1.6 mol / L for treatment for 10 - 15 min; collect the solid by centrifugation and dry it, and then calcine it at 465 - 515 °C for 2 - 4 h; III. Preparation of composite molecular sieve Grind the modified silicoaluminophosphate molecular sieve and the modified ZMQ-1 molecular sieve, and then add silica sol accounting for 20 - 25% of the total amount of the molecular sieve, carry out tabletting, dry it, and then calcine it at 550 - 600 °C for 3 - 4 h; IV. The modified silicoaluminophosphate molecular sieve, the composite molecular sieve, and the modified ZMQ-1 molecular sieve are loaded in layers in sequence to form a catalyst for the production of light olefins from light alcohols.

9. A catalyst for the production of light olefins from light alcohols obtained by the preparation method according to claim 8.

10. Use of the catalyst according to claim 9 in the production of light olefins from light alcohols.

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