Methane oxidation coupling catalyst, method for preparing the same, and method for preparing carbon dihydric hydrocarbon

Abstract

The application relates to the technical field of methane oxidation coupling reaction, and discloses a methane oxidation coupling catalyst, a preparation method thereof and a method for preparing carbon dihydrocarbon. The methane oxidation coupling catalyst provided by the application has the advantages of good C2 hydrocarbon selectivity, high methane conversion rate, long stable reaction time and the like, raw materials of the catalyst are easy to obtain, the preparation method is simple, and the catalyst is very beneficial to industrial popularization and application. When the catalyst is used for methane oxidation coupling reaction, the one-way yield of C2 hydrocarbon is effectively improved, and the reaction efficiency of the methane oxidation coupling reaction and the one-way yield of C2 hydrocarbon can be further improved by combining the preferred reaction mode and conditions of the application.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of methane oxidation coupling reaction, in particular, to a methane oxidation coupling catalyst, a preparation method thereof and a method for preparing carbon dihydric. BACKGROUND

[0002] Natural gas is the most potential alternative energy due to its clean and low pollution and high calorific value. With the increasing development of natural gas resources in China, the large amount of discovery and relatively low price of natural gas have attracted worldwide attention. Methane oxidation coupling for preparing ethylene (referred to as methane oxidation coupling) as one of the direct utilization technologies of methane, the main component of natural gas, has attracted great interest. It can provide new ethylene raw material source in the future when oil resources are short, and has great significance for the conversion and utilization of natural gas.

[0003] Methane oxidation coupling also has certain academic significance, and is one of the most challenging and most concerned research topics in the field of catalysis. Since Keller et al. first proposed the methane oxidation coupling technology in 1982, the technology has been the focus of the catalysis industry, the chemical industry and the oil and gas field. Although researchers have made great efforts to promote the development of the process of direct conversion of natural gas to ethylene, the directional activation of methane is extremely difficult, which limits the further improvement of the single-pass yield of C2 hydrocarbons in the reaction. SUMMARY

[0004] The present application aims to overcome the problems of insufficient single-pass yield of C2 hydrocarbons in the methane oxidation coupling reaction in the prior art, and provides a methane oxidation coupling catalyst, a preparation method thereof and a method for preparing carbon dihydric. The methane oxidation coupling catalyst provided by the present application has the advantages of good C2 hydrocarbon selectivity and high methane conversion rate, effectively improves the single-pass yield of C2 hydrocarbons, and further improves the reaction efficiency of the methane oxidation coupling reaction and the single-pass yield of C2 hydrocarbons in cooperation with the preferred reaction mode and conditions of the present application.

[0005] In order to achieve the above-mentioned purpose, the present application provides a method for preparing a methane oxidation coupling catalyst, which comprises impregnating a carrier BaSO4 in an active component precursor solution, and calcining the impregnated product.

[0006] The active component precursor solution is a water-soluble inorganic salt solution of La and / or Er.

[0007] The content of the active component precursor in the active component precursor solution is such that the weight ratio of La2O3 and / or Er2O3 to the carrier BaSO4 in the prepared catalyst is 1 / 10-1 / 2.

[0008] The second aspect of the present application provides a methane oxidative coupling catalyst prepared by the method as described above.

[0009] The third aspect of the present application provides a method for preparing carbon dihydrocarbon, which comprises mixing a catalyst and a filler uniformly, loading the mixture into a catalyst bed of a methane oxidative coupling reactor, and introducing a reaction gas into the reactor to contact with the catalyst to perform a methane oxidative coupling reaction, wherein the catalyst is the catalyst as described above.

[0010] By the technical solution described above, the present application can achieve the following beneficial effects:

[0011] (1) The catalyst preparation method provided by the present application has the characteristics of simple operation, easy-to-obtain raw materials, large-scale catalyst preparation, avoidance of complicated steps, and is suitable for industrial large-scale popularization and use.

[0012] (2) The catalyst prepared by the method provided by the present application has excellent performance and high stability (the stable reaction time can reach more than 20 hours), and the method for preparing carbon dihydrocarbon provided by the present application can effectively improve the selectivity and single-pass yield of C2 hydrocarbon, and has a good industrial application prospect. DETAILED DESCRIPTION

[0013] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The endpoints of the ranges and any values should be considered to be open-ended ranges for purposes of the disclosure, unless otherwise specified. Thus, the endpoints of the ranges and any values are understood to be approximate values, and thus, any value falling within the range or any value falling within the range can be used in the disclosure. The ranges and any values are understood to include new ranges and values that are within one or more of the disclosed ranges or values.

[0014] The inventors of the present application ingeniously found that, in a methane oxidative coupling catalyst (OCM catalyst) taking an oxide of La and / or an oxide of Er as an active component and taking BaSO4 as a carrier, when the weight ratio of the active component to the carrier is within a certain range, a better catalytic effect can be achieved.

[0015] The present application provides a method for preparing a methane oxidative coupling catalyst, which comprises dipping a carrier BaSO4 in an active component precursor solution, and calcining the dipping product.

[0016] The active component precursor is a La precursor and / or an Er precursor.

[0017] The amount of the active component precursor in the active component precursor solution is such that the weight ratio of the active component precursor calculated as La2O3 and / or Er2O3 to the carrier BaSO4 is 1 / 10-1 / 2.

[0018] According to the preferred embodiment of the present application, the water absorption of the carrier BaSO4 is 3-5 g / g. The "water absorption" refers to the weight of water absorbed by unit mass (g) of the carrier BaSO4. Generally, the water absorption of the carrier BaSO4 is affected by its structure and other factors, and can be detected by capillary method or other methods.

[0019] In the method provided by the present application, the active component precursor is a compound providing active components for the catalyst, which is loaded on the carrier by impregnation, dried and calcined to form a catalytically active substance. The present application does not have particular restrictions on the specific compound of the active component precursor, and in order to facilitate impregnation operation, a water-soluble compound (such as water-soluble acid / alkali / salt) containing active components (elements) is preferably used as the active component precursor.

[0020] According to the preferred embodiment of the present application, the active component precursor is a water-soluble inorganic salt of La and / or Er, preferably lanthanum nitrate and / or erbium nitrate.

[0021] Preferably, the amount of the active component precursor is such that the weight ratio of the La precursor calculated as La2O3 and the Er precursor calculated as Er2O3 is 1-10:1, preferably 5-8:1. It should be noted here that "the La precursor calculated as La2O3" and "the Er precursor calculated as Er2O3" are only used to describe the amount of the precursor, and facilitate the calculation of the proportion of active components, and do not have a limiting effect on the compound used for the specific active component precursor. That is, in the method provided by the present application, the amount of the La precursor and the Er precursor is such that the weight ratio of the active components La2O3 and Er2O3 in the obtained catalyst is 1-10:1, preferably 5-8:1.

[0022] In order to enable as much active components in the active component precursor (solution) to be loaded on the carrier as possible, and considering the cost saving, according to the preferred embodiment of the present application, the impregnation is saturated impregnation. The "saturated impregnation" refers to an impregnation method in which the amount of water used for preparing the impregnation solution does not exceed the upper limit of the total water absorption of the carrier.

[0023] Preferably, the water content in the active component precursor solution (i.e. the amount of water used for preparing the active component precursor solution) does not exceed 120% of the maximum water absorption of the carrier BaSO4, preferably 70-100% of the maximum water absorption of the carrier BaSO4. For example, it can be 70%, 75%, 80%, 85%, 90%, 95%, 100%, or any intermediate value between any two of the above values.

[0024] In order to obtain better impregnation effect, preferably, the method of saturation impregnation comprises dropping at least part of the active component precursor solution onto the carrier BaSO4, and then impregnating the carrier BaSO4 in the remaining part of the active component precursor solution (i.e. the mixture obtained after dropping is directly mixed with the remaining part of the active component precursor solution). That is, in the method provided by the present application, the total volume of the impregnation solution can be calculated according to the amount of the carrier BaSO4, and then the obtained impregnation solution is divided into two parts, one part of the impregnation solution is contacted with the carrier BaSO4 by dropping, and after the dropping is completed, the carrier BaSO4 absorbing part of the impregnation solution is directly placed in the other part of the impregnation solution.

[0025] Preferably, the volume ratio of the part of the active component precursor solution to the remaining part of the active component precursor solution is 3-10:1. Preferably, the volume ratio is 3-8:1.

[0026] In the present application, the impregnation effect can be further improved by adjusting the dropping speed of the active component precursor solution (i.e. the impregnation solution), preferably, the dropping speed of the part of the active component precursor solution is 0.2-1 mL / s, preferably 0.3-0.7 mL / s, relative to 4 g of the carrier BaSO4.

[0027] In order to further improve the uniformity of impregnation, more preferably, the process of impregnation further comprises the operation of stirring the impregnation mixture, preferably the stirring speed is 50-100 rpm, more preferably 60-80 rpm. The stirring can be performed during the impregnation (dropping) or after the dropping is completed.

[0028] In the present application, the solubility of the solute can be improved by appropriately heating the active component precursor solution (the impregnation solution), so that the impregnation is more uniform. According to the preferred embodiment of the present application, the temperature of the active component precursor solution is 30-100℃, preferably 30-80℃.

[0029] According to the preferred embodiment of the present application, the impregnation time is 4-24 h, preferably 6-12 h. The "impregnation time" refers to the time period from the completion of the dropping of the part of the active component precursor solution to the completion of the stirring.

[0030] The inventors of the present application have also found that, by using a step-by-step calcination method with different calcination temperatures and times in different calcination stages, an OCM catalyst with better catalytic effect can be obtained.

[0031] According to the preferred embodiment of the present application, the calcination method is a step-by-step calcination method.

[0032] Preferably, the step-by-step calcination method comprises:

[0033] (a) first calcination: calcination temperature 350-500℃, calcination time 1-5h;

[0034] (b) second calcination: calcination temperature 600-750℃, calcination time 4-8h.

[0035] In the present application, it is to be noted that the first calcination and the second calcination only need to meet the above conditions, and there is no specific limitation on the heating rate, and the state of the catalyst after the first calcination to before the second calcination, and preferably, the temperature required for the second calcination can be reached immediately after the first calcination, and then the second calcination is carried out.

[0036] According to a preferred embodiment of the present application, the method further comprises a step of drying the impregnated product before calcination. Preferably, the drying conditions include: temperature 80-120℃, time 2-12h.

[0037] In order to facilitate loading in the reactor for use, according to a preferred embodiment of the present application, the method further comprises a step of pressing the catalyst obtained after calcination into a shaped form. Preferably, the particle size of the catalyst after pressing is 0.25-0.4mm.

[0038] The second aspect of the present application provides a methane oxidative coupling catalyst, which is prepared according to the method as described above;

[0039] Alternatively, the methane oxidative coupling catalyst comprises a carrier BaSO4 and an active component supported on the carrier BaSO4, the active component comprises La2O3 and / or Er2O3, and the weight ratio of the active component to the carrier BaSO4 is 1 / 10-1 / 2. In the catalyst provided by the present application, the active component exists in the form of La2O3 and / or Er2O3, and exerts catalytic action in this form.

[0040] Preferably, the weight ratio of La2O3 to Er2O3 in the catalyst is 10-1:1, preferably 8-5:1.

[0041] The inventors of the present application found in the research process that when the OCM catalyst provided by the present application is loaded into a methane oxidative coupling reactor in a specific loading manner, and the OCM reaction is carried out under specific conditions to prepare carbon dihydric hydrocarbon, the reaction gas (methane) conversion rate is high, and the carbon dihydric hydrocarbon selectivity and yield are high, and the like excellent effects can be obtained.

[0042] Based on the above finding, the third aspect of the present application provides a method for preparing carbon dihydrocarbon (C2 hydrocarbon), which comprises mixing a catalyst and a filler uniformly and then loading the mixture into a methane oxidative coupling reactor, and introducing a reaction gas into the reactor to contact the catalyst, so as to carry out a methane oxidative coupling reaction, wherein the catalyst is the catalyst as described above.

[0043] In the present application, the filler functions to fill the gaps generated when the catalyst (tabletized particles) is loaded into the reactor catalyst bed, so as to avoid the free radicals generated during the reaction from disappearing (i.e. free radical elimination reaction) by contacting the reactor wall, and thus improve the reaction activity and conversion rate.

[0044] Generally, the particle size of the filler should be smaller than that of the catalyst (tabletized particles) so as to better fill the gaps. According to a preferred embodiment of the present application, the filler is selected from quartz particles with a particle size of not more than 0.4 mm, preferably 0.1-0.3 mm.

[0045] Preferably, the particle size of the filler is not more than that of the catalyst.

[0046] More preferably, the weight ratio of the catalyst to the filler loaded into the methane oxidative coupling reactor is 2-6:1.

[0047] According to a preferred embodiment of the present application, the reaction gas comprises methane and oxygen. In the present application, a better reaction effect can be obtained by adjusting the volume ratio of methane to oxygen in the reaction gas, preferably wherein the volume ratio of methane to oxygen is 2-4:1.

[0048] Preferably, the conditions of the methane oxidative coupling reaction comprise: the reaction temperature is 650-750℃, the space velocity of the reaction gas is 10000-25000 mL·g -1 ·h -1 .

[0049] In order to obtain a better reaction effect, considering the stable reaction time of the catalyst, more preferably, the reaction time of the methane oxidative coupling reaction is 0.5-50 h, preferably 2-30 h, and more preferably 2-20 h.

[0050] The present application will be described in detail below by way of examples. It should be understood that the following examples are only used to exemplarily further explain and illustrate the content of the present application, and are not used to limit the present application.

[0051] The water absorption of BaSO4 (carrier) used in the following examples is 4±1 g / g. Unless otherwise specified, the reagents used are commercially available products purchased from regular chemical suppliers, with a purity of analytical grade.

[0052] Example 1

[0053] Catalyst preparation: 2 g of lanthanum nitrate and 0.5 g of erbium nitrate were added to 14 g of distilled water (80 °C) to completely dissolve, to obtain an active component precursor solution. 4 g of BaSO4 carrier was weighed, and 14.1 g of the active component precursor solution was added dropwise to the BaSO4 carrier at a dropwise adding speed of 0.5 mL / min, after the dropwise adding was completed, it was placed in the remaining active component precursor solution, and stirred at 60 rpm for 2 hours. Then it was dried at 120 °C for 2 hours, and then calcined according to the following conditions:

[0054] First calcination: temperature 350 °C, time 5 hours;

[0055] Second calcination: temperature 750 °C, time 4 hours.

[0056] A powdery catalyst was obtained, which was pressed into shape to obtain an OCM catalyst-1 with a particle size of 40 mesh.

[0057] Methane oxidative coupling reaction: the catalytic reactor was a quartz tube with an inner diameter of 10 mm and a length of 500 mm, 0.6 g of OCM catalyst-1 and 0.3 g of quartz sand with a particle size of 0.2 mm were mixed uniformly and filled in the catalyst bed layer of the reaction tube.

[0058] The raw gas composed of methane and oxygen was mixed and introduced at the top end of the reaction tube. The reaction pressure was the pressure generated by the raw material itself (0.014 MPa). The reaction temperature of the catalyst section was controlled at 750 °C, the volume ratio of methane to oxygen was 2:1, and the reaction gas space velocity was 12000 mL·g -1 ·h -1 .

[0059] Example 2

[0060] Catalyst preparation: 1.8 g of lanthanum nitrate and 0.24 g of erbium nitrate were added to 12 g of distilled water (80 °C) to completely dissolve, to obtain an active component precursor solution. 4 g of BaSO4 carrier was weighed, and 11.2 g of the active component precursor solution was added dropwise to the BaSO4 carrier at a dropwise adding speed of 0.7 mL / min, after the dropwise adding was completed, it was placed in the remaining active component precursor solution, and stirred at 80 rpm for 2 hours. Then it was dried at 80 °C for 6 hours, and then calcined according to the following conditions:

[0061] First calcination: temperature 450 °C, time 3 hours;

[0062] Second calcination: temperature 700 °C, time 6 hours.

[0063] A powdery catalyst was obtained, which was pressed into shape to obtain an OCM catalyst-2 with a particle size of 40 mesh.

[0064] Methane oxidative coupling reaction: The catalytic reactor was a quartz tube with an inner diameter of 10 mm and a length of 500 mm. 0.6 g of OCM catalyst-2 and 0.2 g of quartz sand with a particle size of 0.25 mm were mixed uniformly and loaded at the catalyst bed layer of the reaction tube.

[0065] The raw gas composed of methane and oxygen was mixed and introduced into the top end of the reaction tube. The reaction pressure was the pressure generated by the raw material itself (0.015 MPa). The reaction temperature of the catalyst section was controlled at 700°C, the volume ratio of methane to oxygen was 3:1, and the reaction gas space velocity was 18000 mL·g -1 ·h -1 .

[0066] Example 3

[0067] Catalyst preparation: 2 g of lanthanum nitrate and 2.1 g of erbium nitrate were added to 19 g of distilled water (80°C) to completely dissolve, obtaining an active component precursor solution. 4 g of BaSO4 carrier was weighed, and 20.5 g of the active component precursor solution was added to the BaSO4 carrier at a dropwise adding speed of 0.9 mL / min. After the dropwise adding was completed, it was placed in the remaining active component precursor solution and stirred at 90 rpm for 2 hours. Then it was dried at 100°C for 10 hours, and then calcined according to the following conditions:

[0068] First calcination: temperature 500°C, time 2 hours;

[0069] Second calcination: temperature 600°C, time 8 hours.

[0070] A powder catalyst was obtained, which was pressed into a shaped catalyst with a particle size of 40 mesh OCM catalyst-3.

[0071] Methane oxidative coupling reaction: The catalytic reactor was a quartz tube with an inner diameter of 10 mm and a length of 500 mm. 0.6 g of OCM catalyst-3 and 0.1 g of quartz sand with a particle size of 0.3 mm were mixed uniformly and loaded at the catalyst bed layer of the reaction tube.

[0072] The raw gas composed of methane and oxygen was mixed and introduced into the top end of the reaction tube. The reaction pressure was the pressure generated by the raw material itself (0.016 MPa). The reaction temperature of the catalyst section was controlled at 680°C, the volume ratio of methane to oxygen was 2:1, and the reaction gas space velocity was 24000 mL·g -1 ·h -1 .

[0073] Example 4

[0074] Catalyst preparation: 0.9 g of lanthanum nitrate and 0.7 g of erbium nitrate were added into 15 g of distilled water (80 °C) to completely dissolve, obtaining an active component precursor solution. 4 g of BaS04carrier was weighed, and 13.8 g of the active component precursor solution was added dropwise to the BaS04carrier at a dropwise adding speed of 0.2 mL / min, after the dropwise adding was completed, it was placed in the remaining active component precursor solution, and stirred at 50 rpm for 2 hours. Then it was dried at 80 °C for 8 hours, and then calcined according to the following conditions:

[0075] First calcination: temperature 450 °C, time 3 hours;

[0076] Second calcination: temperature 650 °C, time 5 hours.

[0077] A powdery catalyst was obtained, which was pressed into a shape to obtain an OCM catalyst-4 with a particle size of 40 mesh.

[0078] Methane oxidative coupling reaction: the catalytic reactor was a quartz tube with an inner diameter of 10 mm and a length of 500 mm, 0.6 g of OCM catalyst-4 and 0.15 g of quartz sand with a particle size of 0.2 mm were mixed uniformly and filled in the catalyst bed layer of the reaction tube.

[0079] The raw material gas composed of methane and oxygen was mixed and introduced at the top end of the reaction tube. The reaction pressure was the pressure generated by the raw material itself (0.015 MPa). The reaction temperature of the catalyst section was controlled at 720 °C, the volume ratio of methane to oxygen was 3:1, and the reaction gas space velocity was 21000 mL·g -1 ·h -1 .

[0080] Example 5

[0081] The OCM catalyst-1 was used to carry out the methane oxidative coupling reaction according to the following conditions: the same catalytic reactor as in Example 1 was used, wherein only 0.6 g of OCM catalyst-1 was filled, and no quartz sand was filled. The rest of the conditions and operations were the same as in Example 1.

[0082] Example 6

[0083] The method in Example 1 was used, except that 0.6 g of OCM catalyst-1 was mixed uniformly with 0.8 g of quartz sand with a particle size of 0.2 mm and then filled into the reactor bed layer, and the rest of the conditions and operations were the same as in Example 1.

[0084] Example 7

[0085] The method in Example 1 was used, except that 0.6 g of OCM catalyst-1 was mixed uniformly with 0.3 g of quartz sand with a particle size of 1 mm and then filled into the reactor bed layer, and the rest of the conditions and operations were the same as in Example 1.

[0086] Example 8

[0087] The method in Example 1 was adopted, except that 0.6 g of OCM catalyst-1 was mixed with 0.3 g of quartz sand with a particle size of 0.05 mm uniformly and then loaded into the reactor bed layer, and the rest of the conditions and operations were the same as in Example 1.

[0088] Example 9

[0089] Catalyst preparation: The method in Example 1 was adopted, except that the carrier BaSO4 was directly placed in the active component precursor solution and stirred for 2 h. OCM catalyst-5 was obtained.

[0090] Methane oxidative coupling reaction: The methane oxidative coupling reaction was carried out using OCM catalyst-5, and the conditions and operations were the same as in Example 1.

[0091] Example 10

[0092] Catalyst preparation: The method in Example 1 was adopted, except that lanthanum nitrate and erbium nitrate were replaced by equal weights of lanthanum sulfate and erbium sulfate, respectively. The rest of the steps and operations were the same as in Example 1. OCM catalyst-6 was obtained.

[0093] Methane oxidative coupling reaction: The methane oxidative coupling reaction was carried out using OCM catalyst-6, and the conditions and operations were the same as in Example 1.

[0094] Example 11

[0095] Catalyst preparation: The method in Example 1 was adopted, except that lanthanum nitrate was replaced by equal weight of erbium nitrate. The rest of the steps and operations were the same as in Example 1. OCM catalyst-7 was obtained.

[0096] Methane oxidative coupling reaction: The methane oxidative coupling reaction was carried out using OCM catalyst-7, and the conditions and operations were the same as in Example 1.

[0097] Example 12

[0098] Catalyst preparation: The method in Example 1 was adopted, except that erbium nitrate was replaced by equal weight of lanthanum nitrate. The rest of the steps and operations were the same as in Example 1. OCM catalyst-8 was obtained.

[0099] Methane oxidative coupling reaction: The methane oxidative coupling reaction was carried out using OCM catalyst-8, and the conditions and operations were the same as in Example 1.

[0100] Comparative Example 1

[0101] Catalyst preparation: The method in Example 1 was adopted, except that the amounts of lanthanum nitrate and erbium nitrate were 2 g and 7.2 g, respectively. The remaining steps and operations were the same as in Example 1. An OCM catalyst-D1 was obtained.

[0102] Methane oxidative coupling reaction: The methane oxidative coupling reaction was carried out using the OCM catalyst-D1, and the conditions and operations were the same as in Example 1.

[0103] Test Example 1

[0104] The content of the active component in the OCM catalyst obtained in the above examples and comparative examples was calculated by the amount of the raw material, neglecting trace impurities. The specific surface area and average pore diameter of the OCM catalyst obtained in the above examples and comparative examples were calculated according to the isotherm using the adsorption isotherm full analysis by the ASAP2020 full-automatic physi sorption analyzer of the American MICROMERITICS instrument company.

[0105] The results are shown in Table 1. Among them, the active component content is the weight % relative to the BaSO4 carrier.

[0106] Table 1

[0107]

[0108] *In catalyst-6, 10.7 wt% of S was contained relative to the BaSO4 carrier.

[0109] Test Example 2

[0110] The components and contents in the reaction products collected in the above examples and comparative examples were analyzed by gas chromatography (Agilent type 7890A) instrument, and the methane conversion, C2 hydrocarbon selectivity, CO X selectivity, C2 hydrocarbon yield were calculated using the following formula. The results are shown in Table 2.

[0111] Methane conversion = amount of consumed methane in reaction / initial amount of methane x 100%

[0112] Ethylene selectivity = amount of consumed methane for generated ethylene / total consumption amount of methane x 100%

[0113] Ethane selectivity = amount of consumed methane for generated ethane / total consumption amount of methane x 100%

[0114] C2 hydrocarbon selectivity = ethane selectivity + ethylene selectivity

[0115] CO X (CO+CO2) selectivity = amount of consumed methane for generated CO and CO2 / total consumption amount of methane x 100%

[0116] C2 hydrocarbon yield = methane conversion x (ethane selectivity + ethylene selectivity)

[0117] Table 2

[0118]

[0119] The stable reaction time is determined by the reaction activity (methane conversion and C2 hydrocarbon selectivity) of the catalyst, and when either of the methane conversion and C2 hydrocarbon selectivity continuously decreases (by an amount reaching or exceeding 5%), the reaction is stopped, and the time between the start of the reaction and the stop of the reaction is the stable reaction time.

[0120] The above describes the preferred embodiments of the present application, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as the disclosed content of the present application, and all fall within the protection scope of the present application.

Claims

1. A process for the preparation of a methane oxidation coupling catalyst, characterized in that, The method comprises dipping the carrier BaSO4 in a solution of active component precursor and calcining the dipping product; The active component precursor is lanthanum nitrate and erbium nitrate; The amount of active component precursor in the solution of active component precursor is such that the weight ratio of active component precursor, calculated as La2O3 and Er2O3, to carrier BaSO4 is 1 / 10-1 / 2; The amount of active component precursor is such that the weight ratio of La precursor, calculated as La2O3, to Er precursor, calculated as Er2O3, is 1-10:1; The dipping is saturated dipping, which comprises dropping at least part of the solution of active component precursor onto the carrier BaSO4 and then dipping it in the remaining part of the solution of active component precursor.

2. The method of claim 1, wherein, The water absorption of the carrier BaSO4 is 3-5g / g.

3. The method of claim 1, wherein, The amount of active component precursor is such that the weight ratio of La precursor, calculated as La2O3, to Er precursor, calculated as Er2O3, is 5-8:

1.

4. The method of claim 1, wherein, The dropping speed of the part of the solution of active component precursor is 0.2-1mL / s relative to 4g of carrier BaSO4; The weight ratio of part of the solution of active component precursor to the remaining part of the solution of active component precursor is 3-10:

1.

5. The method of claim 4, wherein, The dipping process further comprises stirring the dipping mixture.

6. The method of claim 4, wherein, The dropping speed of the part of the solution of active component precursor is 0.3-0.7mL / s relative to 4g of carrier BaSO4; The weight ratio of part of the solution of active component precursor to the remaining part of the solution of active component precursor is 3-8:

1.

7. The method of claim 5, wherein, The stirring speed is 50-100rpm.

8. The method of claim 5, wherein, The stirring speed is 60-80rpm.

9. The method of claim 1, wherein, The temperature of the solution of active component precursor is 30-100℃; The dipping time is 4-24h.

10. The method of claim 9, wherein, The temperature of the solution of active component precursor is 30-80℃; The dipping time is 6-12h.

11. The method of claim 9, wherein, The water content in the solution of active component precursor is not more than 120% of the maximum water absorption of the carrier BaSO4 by weight.

12. The method of claim 11, wherein, The water content in the solution of active component precursor is 70-100% of the maximum water absorption of the carrier BaSO4 by weight.

13. The method of claim 1, wherein, The calcination is stepwise calcination.

14. The method of claim 13, wherein, The stepwise calcination comprises: (a) first calcination: calcination temperature 350-500℃, calcination time 1-5h; (b) second calcination: calcination temperature 600-750℃, calcination time 4-8h.

15. The method of claim 1, wherein, The method further comprises a step of drying the dipping product before calcination.

16. The method of claim 15, wherein, The method further comprises a step of pressing the catalyst obtained after calcination into a shape.

17. The method of claim 15, wherein, The drying conditions comprise: temperature 80-120℃, time 2-12h.

18. The method of claim 16, wherein, The particle size of the catalyst after pressing into a shape is 0.25-0.4mm.

19. A methane oxidation coupling catalyst characterized by, The methane oxidation coupling catalyst is prepared according to the method of any one of claims 1-18.

20. The catalyst of claim 19, wherein, The weight ratio of La2O3 to Er2O3 in the catalyst is 5-8:

1.

21. A method of making a carbon dihydride, characterized by, The method comprises loading the catalyst and the filler into a catalyst bed of a methane oxidative coupling reactor after mixing them uniformly, and introducing a reaction gas into the reactor to contact the catalyst, so as to carry out a methane oxidative coupling reaction, wherein the catalyst is the catalyst according to claim 19 or 20.

22. The method of claim 21, wherein, The filler in the catalyst bed is selected from quartz particles with a particle size of not more than 0.4 mm.

23. The method of claim 22, wherein, The filler in the catalyst bed is selected from quartz particles with a particle size of 0.1-0.3 mm.

24. The method of claim 22, wherein, The particle size of the filler is not more than the particle size of the catalyst.

25. The method of claim 22, wherein, The weight ratio of the catalyst to the filler loaded into the methane oxidative coupling reactor is 2-6:

1.

26. The method of claim 21, wherein, The reaction gas comprises methane and oxygen.

27. The method of claim 26, wherein, The volume ratio of methane to oxygen is 2-4:

1. And / or, the conditions of the methane oxidation coupling reaction include: the reaction temperature is 650-750℃, the reaction gas hourly space velocity is 10000-25000 mL·g -1 ·h -1 ; The reaction time of the methane oxidative coupling reaction is 0.5-50 h.

28. The method of claim 27, wherein, The reaction time of the methane oxidative coupling reaction is 2-30 h.

29. The method of claim 27, wherein, The reaction time of the methane oxidative coupling reaction is 2-20 h.

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