Simple synthesis method and application of catalyst for preparing oil from methanol under normal pressure
阅读说明：本技术 一种用于常压下甲醇制油的催化剂的简单合成方法及应用 (Simple synthesis method and application of catalyst for preparing oil from methanol under normal pressure ) 是由 韩睿 陈补生 江婕 郭晓轩 于 2019-12-03 设计创作，主要内容包括：本发明公开了一种用于常压下甲醇制油的催化剂的简单合成方法,包括合成液的制备、分子筛的合成、分子筛的铵离子交换最终制备出ZSM-5分子筛催化剂。通过选择硫酸铝为铝源,硅溶胶为硅源,搅拌混匀后陈化晶化,得到的HZSM-5分子筛催化剂。本发明提供一种程序简单,晶化时间短,催化剂结晶度较高。对甲醇制汽油的催化反应,在常压下使用,对油相产物选择性可达50％或以上；而且催化剂的稳定期在200h以上,同时该催化剂对油相产物的选择性也维持在50％。(The invention discloses a simple synthesis method of a catalyst for preparing oil from methanol under normal pressure, which comprises the steps of preparation of a synthetic solution, synthesis of a molecular sieve and ammonium ion exchange of the molecular sieve to finally prepare a ZSM-5 molecular sieve catalyst. The HZSM-5 molecular sieve catalyst is obtained by selecting aluminum sulfate as an aluminum source and silica sol as a silicon source, uniformly mixing, and then aging and crystallizing. The invention provides a catalyst with simple procedure, short crystallization time and higher crystallinity. The catalytic reaction of methanol to gasoline is used under normal pressure, and the selectivity of oil phase products can reach 50% or more; and the stable period of the catalyst is more than 200h, and the selectivity of the catalyst to oil phase products is also maintained at 50 percent.)
1. A simple synthesis method of a catalyst for preparing oil from methanol under normal pressure is characterized by comprising the following steps: the preparation of the simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure is carried out according to the following steps:
firstly, preparing a synthetic solution, namely weighing a certain amount of alkaline silicon solution, adding a certain amount of template agent, and stirring at a constant speed for 1 hour to prepare a first mixed solution; weighing aluminum sulfate and sodium hydroxide, and fully dissolving the aluminum sulfate and the sodium hydroxide in deionized water to prepare second slurry; slowly adding the prepared second slurry into the first mixed solutionAnd stirring for 2 hours, and uniformly mixing to obtain a synthetic liquid, wherein the molar composition of the synthetic liquid is as follows: SiO 22:Al2O3:Na2O:C4H11N:H2O＝1:0.0042:0.1:0.8:34.6；
Secondly, synthesizing a molecular sieve, namely adding seed crystals with the solid content of 1-5% of the synthetic liquid into the synthetic liquid prepared in the step 1 at room temperature, transferring the material into a stainless steel reaction kettle, sealing the reaction kettle, and aging for 24 hours; then heating to 160 ℃, crystallizing under a hydrothermal condition, and then rapidly cooling to room temperature; washing to be neutral, drying at 100-120 ℃, and roasting at 450-600 ℃ for 4h to obtain ZSM-5 molecular sieve powder;
thirdly, performing ammonium ion exchange on the molecular sieve, preparing 0.5-1.5 mol/L ammonium chloride solution, mixing the ammonium chloride solution and the ZSM-5 molecular sieve powder prepared in the step 2 according to the mass ratio of 10-15: 1, performing ion exchange at 75-90 ℃ for 2-4 h, and performing centrifugal separation; repeating the process of centrifugal separation after ion exchange for 1-3 times; then washing, drying and roasting to obtain the HZSM-5 molecular sieve catalyst;
fourthly, carrying out hydrothermal treatment on the molecular sieve, namely filling the HZSM-5 molecular sieve catalyst into a container, and introducing steam for hydrothermal treatment, wherein the temperature of the steam is 300-800 ℃, and the airspeed is 2-4 h-1And the treatment time is 6-12 h.
2. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: the alkaline silicon solution is one of silica sol, ethyl orthosilicate vinegar or water glass.
3. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: the template agent is n-butylamine.
4. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: and in the second step, the crystallization time is 36-72 h.
5. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: and in the third step, the concentration of the ammonium chloride solution is 1.0mol/L, and the ammonium chloride solution and the ZSM-5 molecular sieve powder prepared in the second step are mixed according to the mass ratio of 10: 1.
6. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: in the fourth step, the temperature of the steam is 400 ℃, and the airspeed is 4h-1And the treatment time is 8 h.
7. The simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure according to claim 1, which is characterized in that: the prepared HZSM-5 molecular sieve catalyst has the silica-alumina ratio of 10-120 and the specific surface area of 300-500 m2·g-lThe pore volume is 0.20-0.50 cm3·g-1The average pore diameter is 2.00-5.00 nm.
8. Use of a catalyst according to any one of claims 1 to 7 for atmospheric methanol-to-oil, characterized in that: the HZSM-5 molecular sieve catalyst contacts with methanol, and the methanol is catalyzed to react under normal pressure to prepare gasoline; the HZSM-5 molecular sieve catalyst has a stable period of more than or equal to 200h, and the selectivity of an oil phase product is more than or equal to 50%.
9. The use of the catalyst according to claim 8 for the preparation of oil from methanol under atmospheric pressure, wherein: the reaction conditions of the reaction for preparing the gasoline by contacting the HZSM-5 molecular sieve catalyst with the methanol are as follows: normal pressure, reaction temperature of 320-420 ℃; the raw material directly adopts a crude methanol solution, and WHSV is 0.2-2.0 g/gcat/h.
Technical Field
The invention relates to the technical field of preparation of HZSM-5 molecular sieve catalysts, in particular to a simple synthesis method and application of a catalyst for preparing oil from methanol under normal pressure.
Background
China is wide in region, large in population and large in energy demand. But the crude oil resource is deficient and depends heavily on import. Therefore, relatively rich coal resources become the inevitable choice of energy in China. The coal-based methanol is a relatively mature technology project with high productivity in China. The synthesis of gasoline from methanol is simple, and the methanol to oil (MTG) has high strategic value in the aspect of energy safety. In addition, the methanol productivity is higher, and the method is helpful for the domestic coal industry to produce the methanol. MTG is therefore becoming a focus of increasing attention in the context of such social and economic needs.
The existing catalyst for preparing gasoline from methanol cannot give consideration to the high selectivity of an oil phase product and the long service life of the catalyst, and meanwhile, the process is simplified in the aspect of catalyst synthesis, and the cost is saved. Meanwhile, the preparation process of the catalyst has the problems of longer crystallization time, reduced crystallinity, more complex process and the like.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a simple synthesis method and application of a catalyst for preparing oil from methanol under normal pressure, which has the advantages of simple procedure, short crystallization time, higher catalyst crystallinity, higher oil phase product selectivity and longer service life for the catalytic reaction of preparing gasoline from methanol.
The invention is realized by the following modes: a simple synthesis method of a catalyst for preparing oil from methanol under normal pressure is characterized by comprising the following steps: the preparation of the simple synthesis method of the catalyst for preparing the oil from the methanol under the normal pressure is carried out according to the following steps:
firstly, preparing a synthetic solution, namely weighing a certain amount of alkaline silicon solution, adding a certain amount of template agent, and stirring at a constant speed for 1 hour to prepare a first mixed solution; weighing aluminum sulfate and sodium hydroxide, and fully dissolving the aluminum sulfate and the sodium hydroxide in deionized water to prepare second slurry; slowly adding the prepared second slurry into the first mixed solution, stirring for 2 hours, and uniformly mixing to obtain a synthetic solution, wherein the molar composition of the synthetic solution is as follows: SiO 22:Al2O3:Na2O:C4H11N:H2O＝1:0.0042:0.1:0.8:34.6；
Secondly, synthesizing a molecular sieve, namely adding seed crystals with the solid content of 0-5% of the synthetic liquid into the synthetic liquid prepared in the step 1 at room temperature, transferring the material into a stainless steel reaction kettle, sealing the reaction kettle, and aging for 24 hours; then heating to 160 ℃, crystallizing under a hydrothermal condition, and then rapidly cooling to room temperature; washing to be neutral, drying at 100-120 ℃, and roasting at 450-600 ℃ for 4h to obtain ZSM-5 molecular sieve powder;
thirdly, performing ammonium ion exchange on the molecular sieve, preparing 0.5-1.5 mol/L ammonium chloride solution, mixing the ammonium chloride solution and the ZSM-5 molecular sieve powder prepared in the step 2 according to the mass ratio of 10-15: 1, performing ion exchange at 75-90 ℃ for 2-4 h, and performing centrifugal separation; repeating the centrifugal separation process for 1-3 times after ion exchange; then washing, drying and roasting to obtain the HZSM-5 molecular sieve catalyst;
fourthly, carrying out hydrothermal treatment on the molecular sieve, namely filling the HZSM-5 molecular sieve catalyst into a container, and introducing steam for hydrothermal treatment, wherein the temperature of the steam is 300-800 ℃, and the airspeed is 2-4 h-1And the treatment time is 6-12 h.
Further, the alkaline silicon solution is one of silica sol, ethyl orthosilicate vinegar or water glass.
Further, the template agent is n-butylamine.
Further, the crystallization time in the second step is 36-72 hours.
Further, the concentration of the ammonium chloride solution in the third step is 1.0mol/L, and the ammonium chloride solution and the ZSM-5 molecular sieve powder prepared in the second step are mixed according to the mass ratio of 10-15: 1.
Further, the prepared HZSM-5 molecular sieve catalyst has the silica-alumina ratio of 10-120 and the specific surface area of 300-500 m2·g-lThe pore volume is 0.20-0.50 cm3·g-1The average pore diameter is 2.00-5.00 nm.
Further, contacting the HZSM-5 molecular sieve catalyst with methanol, and catalyzing the methanol to react under normal pressure to prepare gasoline; the HZSM-5 molecular sieve catalyst has a stable period of more than or equal to 200h, and the selectivity of an oil phase product is more than or equal to 50%.
Further, the reaction conditions of the reaction for preparing the gasoline by contacting the HZSM-5 molecular sieve catalyst with the methanol are normal pressure and the reaction temperature of 320-420 ℃; the raw material directly adopts a crude methanol solution, and WHSV is 0.2-2.0 g/gcat/h.
The invention has the beneficial effects that: the HZSM-5 molecular sieve catalyst is prepared by selecting aluminum sulfate as an aluminum source and silica sol as a silicon source, uniformly mixing and stirring, and then aging and crystallizing. The HZSM-5 molecular sieve catalyst after hydrothermal treatment can effectively improve the stability time of the catalyst, and the selectivity of the catalyst to an oil phase product can reach 50% or more when the catalyst is used for a catalytic reaction of methanol to gasoline under normal pressure; the stable period of the catalyst is more than 200 h; the catalyst has the longest stable period of 500h, and has selectivity of 50% to oil phase product.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention will be described in detail and completely with reference to the accompanying drawings. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", "both ends", "one end", "the other end", etc., indicate relative orientations or positional relationships, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "provided," "connected," and the like are to be construed broadly, such as "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.