Short-period preparation method of catalyst for methane oxidative coupling reaction, catalyst for methane oxidative coupling reaction and application of catalyst

文档序号：1968733 发布日期：2021-12-17 浏览：19次中文

阅读说明：本技术 甲烷氧化偶联反应用催化剂的短周期制备方法及甲烷氧化偶联反应用催化剂和其应用 (Short-period preparation method of catalyst for methane oxidative coupling reaction, catalyst for methane oxidative coupling reaction and application of catalyst ) 是由武洁花刘东兵白杰于 2020-06-17 设计创作，主要内容包括：本发明涉及催化剂领域,公开了一种甲烷氧化偶联反应用催化剂的短周期制备方法及甲烷氧化偶联反应用催化剂和其应用。制备方法包括：使用碳酸氧镧的前驱体浸渍液对载体进行微波浸渍,然后将浸渍后的固体物料依次进行干燥和焙烧,得到所述负载型催化剂；其中,所述碳酸氧镧的前驱体浸渍液含有镧的可溶性盐、可溶性碳源和水；其中,所述载体为埃洛石；其中,所述可溶性碳源为碳酸盐和/或碳酸氢盐,其中,所述浸渍液的pH值为8-14。本发明的催化剂制备时间可大大降低,解决了现有制备工艺周期长的问题,并且本发明提供的催化剂且用于甲烷氧化偶联反应时,还具有较高的反应转化率和选择性。(The invention relates to the field of catalysts, and discloses a short-period preparation method of a catalyst for methane oxidative coupling reaction, a catalyst for methane oxidative coupling reaction and application thereof. The preparation method comprises the following steps: carrying out microwave impregnation on the carrier by using a precursor impregnation liquid of lanthanum oxycarbonate, and then drying and roasting the impregnated solid material in sequence to obtain the supported catalyst; the precursor impregnation liquid of the lanthanum oxycarbonate contains soluble salt of lanthanum, a soluble carbon source and water; wherein the carrier is halloysite; wherein the soluble carbon source is carbonate and/or bicarbonate, and the pH value of the impregnation liquid is 8-14. The preparation time of the catalyst can be greatly reduced, the problem of long period of the existing preparation process is solved, and the catalyst provided by the invention has higher reaction conversion rate and selectivity when being used for methane oxidative coupling reaction.)

1. A method of preparing a supported catalyst, the method comprising: carrying out microwave impregnation on the carrier by using a precursor impregnation liquid of lanthanum oxycarbonate, and then drying and roasting the impregnated solid material in sequence to obtain the supported catalyst;

the precursor impregnation liquid of the lanthanum oxycarbonate contains soluble salt of lanthanum, a soluble carbon source and water;

wherein the carrier is halloysite;

wherein the soluble carbon source is a carbonate and/or bicarbonate;

wherein the pH value of the impregnation liquid is 8-14.

2. The method as claimed in claim 1, wherein the power of the microwave is 300-;

preferably, the microwave impregnation temperature is 20-40 ℃ and the time is 1-20 min.

3. The method of claim 1 or 2, wherein the impregnation solution has a pH value of 9-12; and/or

The soluble carbon source is at least one of alkali metal carbonate, alkali metal bicarbonate, ammonium carbonate and ammonium bicarbonate.

4. The method as claimed in any one of claims 1 to 3, wherein the halloysite is a hollow nanotube structure having an inner diameter of 10-20nm, an outer diameter of 40-70nm and a length of 200-1000 nm.

5. The process according to any one of claims 1 to 4, wherein the amount of the precursor of lanthanum oxycarbonate is such that the lanthanum oxycarbonate is contained in the resulting supported catalyst in an amount of 0.5 to 60 parts by weight, preferably 2 to 30 parts by weight, relative to 100 parts by weight of the support on a dry weight basis.

6. The method of any of claims 1-5, wherein the drying conditions comprise: the temperature is 80-180 ℃, and the time is 12-24 hours; and/or

The roasting conditions comprise: the temperature is 450 ℃ and 600 ℃, and the time is 2-8 hours;

preferably, the calcination is performed in an atmosphere of air or carbon dioxide.

7. The method according to any one of claims 1 to 6, wherein the temperature of the dried material is raised to the roasting temperature at a rate of 1-10 ℃/min.

8. The method of any of claims 1-7, wherein the method further comprises: supporting an auxiliary element on the carrier;

preferably, the auxiliary element is a metal element, a semimetal element, a nonmetal element or a combination thereof, and more preferably any one or any combination of Li, Na, K, Cs, Ce, Y, Ba, Ti, Ru, Rh, Ni, Sr, Ag and Pt;

preferably, the promoter element is used in an amount such that the promoter element is present in an amount of 0.01 to 5 parts by weight, based on 100 parts by weight of the carrier on a dry weight basis, in the resulting supported catalyst.

9. A supported catalyst, characterized in that it is obtained by a process according to any one of claims 1 to 8.

10. A supported catalyst, which is characterized by comprising a carrier and an active component supported on the carrier, wherein the carrier is halloysite; the active component comprises lanthanum oxycarbonate;

the catalyst also comprises an auxiliary agent element loaded on the carrier, wherein the auxiliary agent element comprises barium element and strontium element.

11. The supported catalyst of claim 10, wherein the lanthanum oxycarbonate is present in an amount of 0.5 to 60 parts by weight relative to 100 parts by weight of the support on a dry weight basis; the content of the auxiliary agent element is 0.01-5 parts by weight.

12. The supported catalyst of claim 10 or 11, wherein the halloysite is a hollow nanotube structure with an inner diameter of 10-20nm, an outer diameter of 40-70nm, and a length of 200-1000 nm.

13. The supported catalyst of any of claims 10-11, wherein the promoter element further comprises any one or any combination of Li, Na, K, Cs, Ce, Y, Ti, Ru, Rh, Ni, Ag, and Pt.

14. The supported catalyst of any one of claims 10-13, wherein the supported catalyst is prepared by a process comprising: carrying out microwave impregnation on the carrier by using impregnation liquid containing a precursor of lanthanum oxycarbonate and a precursor of an auxiliary agent element, and then sequentially drying and roasting the impregnated solid material to obtain the supported catalyst;

the precursor of the lanthanum oxycarbonate comprises a soluble salt of lanthanum and a soluble carbon source;

wherein the carrier is halloysite;

wherein the soluble carbon source is a carbonate and/or bicarbonate;

wherein the pH value of the impregnation liquid is 8-14.

15. Use of a supported catalyst according to any one of claims 9 and 10 to 14 in an oxidative coupling reaction of methane.

16. A method for producing carbon dioxide and hydrocarbons from methane, the method comprising: contacting methane with the supported catalyst of any one of claims 9 and 10-14 in the presence of oxygen and under conditions of a methane oxidative coupling reaction;

alternatively, a supported catalyst is prepared according to the process of any one of claims 1 to 8, and then methane is contacted with the resulting supported catalyst in the presence of oxygen and under conditions of the oxidative coupling reaction of methane.

17. The process according to claim 16, wherein the molar ratio of the amounts of methane and oxygen is 2-10: 1, preferably 3-8: 1;

and/or the contact temperature is 400-800 ℃; the space velocity of the methane is 5000-100000 mL/(g.h).

Technical Field

The invention relates to the field of catalysts, in particular to a microwave preparation method of a supported catalyst loaded with lanthanum oxycarbonate, the supported catalyst loaded with lanthanum oxycarbonate prepared by the microwave preparation method, the supported catalyst loaded with lanthanum oxycarbonate, application of the supported catalyst loaded with lanthanum oxycarbonate in methane oxidative coupling reaction, and a method for preparing carbon dioxide and hydrocarbon from methane.

Background

Ethylene is a compound consisting of two carbon atoms and four hydrogen atoms. The two carbon atoms are connected by a double bond.

Ethylene is a basic chemical raw material of synthetic fiber, synthetic rubber, synthetic plastics (polyethylene and polyvinyl chloride), synthetic ethanol (alcohol), is also used for manufacturing vinyl chloride, styrene, ethylene oxide, acetic acid, acetaldehyde, ethanol, explosive and the like, can be used as a ripener for fruits and vegetables, and is a proven plant hormone.

Ethylene is one of the chemical products with the largest yield in the world, the ethylene industry is the core of the petrochemical industry, and the ethylene product accounts for more than 75 percent of petrochemical products and occupies an important position in national economy. Ethylene production has been used worldwide as one of the important indicators for the development of petrochemical in one country.

In recent years, the discovery and exploitation of shale gas have revolutionized the development and utilization of natural gas. Therefore, the method for preparing ethane and ethylene by methane oxidative coupling, which is the most direct, effective and economically competitive natural gas utilization method, is increasingly receiving attention. Since the oxidative coupling reaction of methane is a strongly exothermic reaction and is carried out at high temperature, no industrial production is available so far, and therefore, the development of a methane oxidative coupling catalyst with excellent performance has practical significance.

However, the existing catalyst preparation process is complicated, the preparation time is long, and the industrial production method is not facilitated.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide a microwave preparation method of a supported catalyst loaded with lanthanum oxycarbonate, the supported catalyst loaded with lanthanum oxycarbonate prepared by the microwave preparation method, the supported catalyst loaded with lanthanum oxycarbonate, the application of the supported catalyst loaded with lanthanum oxycarbonate in methane oxidative coupling reaction and a method for preparing carbon dioxide and above hydrocarbons from methane. The preparation time of the catalyst can be greatly reduced, the problem of long period of the existing preparation process is solved, and the catalyst provided by the invention has higher reaction conversion rate and selectivity when being used for methane oxidative coupling reaction.

In order to achieve the above object, a first aspect of the present invention provides a method for preparing a supported catalyst, the method comprising: carrying out microwave impregnation on the carrier by using a precursor impregnation liquid of lanthanum oxycarbonate, and then drying and roasting the impregnated solid material in sequence to obtain the supported catalyst;

the precursor impregnation liquid of the lanthanum oxycarbonate contains soluble salt of lanthanum, a soluble carbon source and water;

wherein the carrier is halloysite;

wherein the soluble carbon source is a carbonate and/or bicarbonate;

wherein the pH value of the impregnation liquid is 8-14.

In a second aspect the present invention provides a supported catalyst prepared by a process as described above.

The third aspect of the present invention provides a supported catalyst comprising a carrier and an active component supported on the carrier, wherein the carrier is halloysite; the active component comprises lanthanum oxycarbonate;

the catalyst also comprises an auxiliary agent element loaded on the carrier, wherein the auxiliary agent element comprises barium element and strontium element.

In a fourth aspect, the present invention provides the use of a supported catalyst as described above in an oxidative coupling reaction of methane.

In a fifth aspect, the present invention provides a method for producing hydrocarbons from methane, the method comprising: contacting methane with a supported catalyst as described above in the presence of oxygen and under conditions for the oxidative coupling of methane;

alternatively, the supported catalyst is prepared as described above and then methane is contacted with the resulting supported catalyst in the presence of oxygen and under conditions of the oxidative coupling of methane reaction.

The invention can obtain the following beneficial effects:

(1) according to the invention, halloysite is used as a carrier, lanthanum oxycarbonate is used as an active component, and the active component is loaded on the carrier by combining a microwave method, so that the preparation time of the catalyst is effectively shortened, a good foundation is laid for industrial amplification production, and more importantly, the obtained catalyst also shows better catalytic performance.

(2) The catalyst provided by the invention takes halloysite as a carrier and lanthanum oxycarbonate as an active component, and still has high reaction conversion rate and selectivity at a low catalytic temperature, for example, below 500 ℃ when used in the oxidative coupling reaction of methane.

(3) The halloysite carrier in the catalyst provided by the invention has a hollow fiber tubular nano structure, and due to the special hollow fiber tubular nano structure and the characteristic that the surface charges of the inner tube and the outer tube are different, the dispersion of active components and the generation of active oxygen sites are facilitated, and the halloysite carrier shows good catalytic performance when being used for methane oxidation coupling reaction.

(4) The carrier halloysite in the catalyst provided by the invention has wide sources and low cost, does not need any treatment, can be directly used as a catalyst carrier, and simplifies the preparation process of the catalyst.

(5) In a preferable condition, the catalyst is loaded with the auxiliary element, so that the catalytic performance of the catalyst is further improved.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect, the present invention provides a process for the preparation of a supported catalyst, the process comprising: carrying out microwave impregnation on the carrier by using a precursor impregnation liquid of lanthanum oxycarbonate, and then drying and roasting the impregnated solid material in sequence to obtain the supported catalyst;

the precursor impregnation liquid of the lanthanum oxycarbonate contains soluble salt of lanthanum, a soluble carbon source and water;

wherein the carrier is halloysite;

wherein the soluble carbon source is a carbonate and/or bicarbonate;

wherein the pH value of the impregnation liquid is 8-14.

Halloysite is a natural aluminosilicate clay mineral, is mainly used for researches on antibacterial, chemical templates, lithium ion batteries and the like, and has a hollow tubular nano structure, the diameter of the hollow tubular nano structure is nano-scale, and the length of the hollow tubular nano structure is between nano-scale and micron-scale; the halloysite has different chemical compositions on the inner wall and the outer wall, the outer wall is made of silicon oxide, the inner wall is made of aluminum oxide, the structure is unique, the charges on the surfaces of the halloysite are different, the outer wall is negatively charged, and the inner wall is positively charged.

The inventor of the invention finds that the supported catalyst is obtained by using halloysite as a carrier and performing microwave impregnation on the halloysite in an impregnation liquid containing a soluble salt of lanthanum, a carbon source (carbonate and/or bicarbonate) and water under an alkaline condition, and then sequentially drying and roasting the impregnated solid material, so that the preparation time of the catalyst is effectively shortened, and the obtained catalyst can perform methane oxidative coupling reaction at a lower temperature while maintaining higher catalytic performance.

The present invention does not impose undue requirements on the specific size of the halloysite. However, the inventors of the present invention have found that when the halloysite of the hollow tubular nanostructure has an inner diameter of 10 to 20nm (for example, may be 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, and any combination of ranges and all values within ranges), an outer diameter of 40 to 70nm (for example, may be 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, and any combination of ranges and all values within ranges), and a length of 200-1000nm (for example, may be 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, and any combination of ranges and all values within ranges), the catalytic performance of the catalyst prepared therefrom can be further improved.

According to the present invention, the soluble salt of lanthanum may be any of the existing soluble salts of lanthanum, such as, but not limited to, lanthanum chloride, lanthanum chlorate and lanthanum nitrate, preferably lanthanum nitrate.

According to the present invention, the carbonate and/or bicarbonate may be any of the existing soluble carbonates and/or bicarbonates, for example, but not limited to, at least one of a carbonate, an alkali metal bicarbonate, ammonium carbonate and ammonium bicarbonate; preferably at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium carbonate and ammonium bicarbonate. When the carbon source is selected from alkali metal carbonate and/or bicarbonate, alkali metal elements can be further introduced into the catalyst, so that the performance of the catalyst is further improved.

According to the invention, the pH of the impregnation liquid may be 8, 9, 10, 11, 12, 13, 14, preferably 9-12, for example 9, 9.5, 10, 10.5, 11, 11.5, 12.

According to the invention, when the added carbon source can enable the pH value of the system to reach the level, the additional pH regulator can not be introduced any more, and if the added carbon source can not enable the pH value of the system to reach the level, the additional pH regulator can be further introduced to adjust the pH value.

According to the present invention, the amount of the precursor of lanthanum oxycarbonate may be selected from a wide range, and is preferably such that the lanthanum oxycarbonate is contained in the obtained catalyst in an amount of 0.5 to 60 parts by weight (for example, may be 0.5 parts by weight, 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight), preferably 2 to 30 parts by weight, more preferably 5 to 15 parts by weight, relative to 100 parts by weight of the carrier on a dry weight basis.

According to the invention, the impregnation may be an isovolumetric impregnation or an over-volumetric impregnation.

According to the present invention, the power of the microwave can be changed in a wide range, preferably, the power of the microwave is 300-1000W (for example, 300W, 400W, 500W, 600W, 700W, 800W, 900W, 1000W), preferably 400-800W.

According to the invention, in addition to controlling the pH as above during microwave impregnation, the temperature and time for other conditions, such as microwave impregnation, may be varied within a wide range. Preferably, the microwave impregnation temperature is room temperature, for example, 20-40 ℃, for example, can be 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃. Preferably, the microwave immersion time is 1-20min, for example, 1min, 3min, 5min, 7min, 9min, 11min, 13min, 15min, 17min, 19min, 20min, preferably 5-10 min.

According to the invention, the temperature of the drying can vary within wide limits, preferably the temperature of the drying is 80 to 180 ℃, for example 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, preferably 80 to 100 ℃.

According to the invention, the drying time can vary within wide limits, preferably the drying time is 12-24h, for example 12h, 14h, 16h, 18h, 20h, 22h, 24h, preferably 12-15 h.

According to the present invention, the temperature of the calcination may be varied within a wide range, and preferably, the temperature of the calcination is 450-.

According to the invention, the calcination time can vary within wide limits, preferably the calcination time is 2 to 8 hours, for example 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, preferably 2 to 6 hours, more preferably 2 to 4 hours.

According to the present invention, the atmosphere for the calcination is not particularly limited, and is preferably an air atmosphere or a carbon dioxide atmosphere.

According to the present invention, in order to further improve the catalytic performance of the prepared supported catalyst, it is preferable that the calcination process is raised to the calcination endpoint temperature at a temperature rise rate of 1 to 10 ℃/min, preferably 1 to 5 ℃/min, and then the calcination is performed for a predetermined time.

According to the present invention, in order to further improve the performance of the prepared supported catalyst, preferably, the method further comprises: and loading the auxiliary agent element on the carrier.

Preferably, the auxiliary element is a metal element, a semimetal element, a nonmetal element or a combination thereof, more preferably any one or any combination of Li, Na, K, Cs, Ce, Y, Ba, Ti, Ru, Rh, Ni, Sr, Ag and Pt, for example, a combination of Ba and Sr.

The method of supporting the auxiliary element on the support is not particularly limited in the present invention, and may be carried out by methods known to those skilled in the art, for example, mixing, precipitation/co-precipitation, impregnation, sol-gel, template/surface-derived metal oxide synthesis, solid state synthesis of mixed metal oxides, microemulsion technology, solvothermal synthesis, sonochemical synthesis, combustion synthesis, and the like.

The method of providing the auxiliary element may be selected by those skilled in the art according to the supporting method, for example, when the supporting method is adopted, the carrier may be impregnated with an impregnation solution containing a soluble salt of the auxiliary element, so as to complete the supporting, and this step may be performed together with or separately from the impregnation of the carrier with the impregnation solution of the precursor of lanthanum oxycarbonate, and after all of the auxiliary element is supported on the carrier, the carrier may be sequentially dried and calcined.

In accordance with the present invention, the amount of the compound containing a promoter element may be selected within a wide range, and in order to further enhance the performance of the supported catalyst, it is preferred that it be used in an amount such that the promoter element is present in the resulting catalyst in an amount of 0.01 to 5 parts by weight, and all ranges therebetween, such as about 0.1 to 4 parts by weight, about 1 to 3 parts by weight, and any specific value therebetween, for example, about 0.01 parts by weight, about 0.02 parts by weight, about 0.5 parts by weight, about 1 part by weight, about 2 parts by weight, about 3 parts by weight, about 4 parts by weight, or about 5 parts by weight, relative to 100 parts by weight of the support on a dry weight basis.

In a second aspect, the present invention provides a supported catalyst prepared by a process as described above.

In a third aspect, the present invention provides a supported catalyst, which comprises a carrier and an active component supported on the carrier, wherein the carrier is halloysite; the active component comprises lanthanum oxycarbonate;

the catalyst also comprises an auxiliary agent element loaded on the carrier, wherein the auxiliary agent element comprises barium element and strontium element.

According to the invention, the lanthanum oxycarbonate may be present, for example, in an amount of 0.5 to 60 parts by weight, preferably 2 to 30 parts by weight, more preferably 5 to 15 parts by weight, relative to 100 parts by weight of the support on a dry weight basis; the content of the auxiliary agent is 0.01 to 5 parts by weight, preferably 0.1 to 4 parts by weight, more preferably 1 to 3 parts by weight, based on the auxiliary agent element.

According to the present invention, in order to further improve the performance of the supported catalyst, it is preferable that the auxiliary element further includes any one or any combination of Li, Na, K, Cs, Ce, Y, Ti, Ru, Rh, Ni, Ag, and Pt.

According to the present invention, the preparation method of the catalyst preferably comprises: carrying out microwave impregnation on the carrier by using impregnation liquid containing a precursor of lanthanum oxycarbonate and a precursor of an auxiliary agent element, and then sequentially drying and roasting the impregnated solid material to obtain the supported catalyst;

the precursor of the lanthanum oxycarbonate comprises a soluble salt of lanthanum and a soluble carbon source;

wherein the carrier is halloysite;

wherein the soluble carbon source is a carbonate and/or bicarbonate;

wherein the pH value of the impregnation liquid is 8-14.

The details of the preparation process according to the present invention have been fully described above in the first aspect, and the present invention will not be repeated herein in order to avoid unnecessary repetition.

In a fourth aspect, the present invention provides the use of a supported catalyst as described above in an oxidative coupling reaction of methane.

According to the present invention, the catalyst of the present invention may be used in a continuous flow reactor to produce C2+ hydrocarbons from methane (e.g., natural gas). The continuous flow reactor may be a fixed bed reactor, a stacked bed reactor, a fluidized bed reactor, a moving bed reactor, or an ebullating bed reactor. The catalyst may be arranged in layers in a continuous flow reactor (e.g., a fixed bed) or mixed with a reactant stream (e.g., an ebullating bed).

In a fifth aspect, the present invention provides a process for the preparation of carbon two and above hydrocarbons from methane, the process comprising: contacting methane with a supported catalyst as described above in the presence of oxygen and under conditions for the oxidative coupling of methane;

According to the present invention, the catalyst may be molded before being loaded in the reactor, and the molding method is not particularly limited and may be a method conventionally used in the art. Preferably, the molding condition is that the mixture is crushed and sieved by a 40-60 mesh sieve after tabletting.

According to the present invention, the conditions for the oxidative coupling of methane reaction are not particularly limited, and may be conventionally selected in the art, and the conditions for the oxidative coupling of methane reaction may include a reaction temperature of 400-. In order to increase the methane conversion, it is preferred that the molar ratio of the amounts of methane and oxygen is 2 to 10: 1, preferably 3 to 8: 1.

embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents and apparatus used are those which are not specified by the manufacturer and are conventional products commercially available.

The drying box is produced by Shanghai-Hengchang scientific instruments Co., Ltd, and has the model of DHG-9030A.

The muffle furnace is manufactured by CARBOLITE corporation, model CWF 1100.

Analysis of the reaction product composition was performed on a gas chromatograph available from Agilent under model 7890A. Methane conversion and selectivity to carbon and above hydrocarbons were calculated based on product composition, including ethane, ethylene, propane, propylene, butane, butenes.

Example 1