A catalyst for hydrogen production by reforming of sour natural gas containing sulfur and a method for preparing the same

Abstract

The application provides a sulfur-containing acid natural gas reforming hydrogen catalyst and a preparation method thereof. Specifically, the catalyst comprises molybdenum disulfide and aluminum silicate, and the mass ratio of molybdenum disulfide to aluminum silicate is 1:9-9:1; preferably, the mass ratio of molybdenum disulfide to aluminum silicate is 2:8-8:2. The molybdenum disulfide / aluminum silicate catalyst shows good activity, selectivity and hydrogen yield in the process of H2S and CH4 reforming hydrogen in the presence of CO2.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production, specifically relating to a sulfuric acid-containing natural gas reforming hydrogen production catalyst and its preparation method. Background Technology

[0002] Hydrogen is a clean, renewable, zero-carbon energy source and an important raw material in industries such as petroleum refining, food processing, pharmaceuticals, and chemical production. Currently, over 95% of the world's hydrogen is produced from fossil resources such as coal, oil, and natural gas, with more than half produced from natural gas. Natural gas's main component is methane (CH4), and its reserves on Earth are enormous; currently, proven global natural gas reserves exceed 140 trillion cubic meters. The main technologies for producing hydrogen from natural gas include steam reforming, partial oxidation, and autothermal reforming. my country successfully developed hydrocarbon steam reforming technology in the 1960s and successfully built its first hydrogen production unit using natural gas as feedstock at the Daqing Refinery. Through long-term industrialization and production practice, my country's capabilities in researching, designing, and constructing natural gas hydrogen production units have approached world-class levels. In recent years, technologies related to natural gas hydrogen production have matured, and industrial hydrogen production units have become increasingly large-scale. In June 2023, my country's largest single-series natural gas hydrogen production unit, with a capacity of 100,000 cubic meters per hour, was put into operation in Zhejiang Province. On the other hand, with the continuous extraction of natural gas, the proportion of sour natural gas is increasing. Sour natural gas contains significant amounts of sulfides (sulfur content higher than 20 mg / m³). 3 Hydrogen sulfide (H2S) and acidic gases such as CO2 must be treated before they meet pipeline transportation standards or commercial gas quality indicators. In China, the hydrogen sulfide (H2S) content is 1 g / m³. 3 Natural gas accounts for approximately 91% of the total, and the proven H2S content exceeds 30 g / m³. 3 The high-sulfur natural gas reserves are estimated at approximately 920 billion cubic meters. In June 2023, the Tieshanpo Gas Field, my country's first independently developed ultra-high-sulfur gas field, reached full production, producing 4 million cubic meters of natural gas per day. The Tieshanpo Gas Field has the highest H2S volume content reaching 16.59% (equivalent to 252 g / m³). 3 According to the "Classification of Natural Gas Reservoirs" GB / T26979, this is an ultra-high sulfur content gas reservoir, currently the highest H2S content integrated gas field in China. H2S is a highly toxic, flammable, explosive, and highly corrosive gas, posing a significant threat to natural gas pipeline transportation. It is also a poison for the catalyst in the natural gas-to-hydrogen process. Therefore, the first step in current hydrogen production technologies using natural gas as feedstock in domestic and international plants is desulfurization of the feedstock gas. However, removing the large amount of H2S from ultra-high sulfuric acid content natural gas would undoubtedly increase process complexity and significantly raise production costs. Therefore, developing a special hydrogen production process using ultra-high sulfuric acid content natural gas as feedstock is imperative.

[0003] Chinese invention patent application CN107497499A discloses an integral clustered alumina supported catalyst for the catalytic reforming reaction of H2S and CH4. According to thermodynamic analysis, the main product of this reaction is hydrogen (Li Yuyang, et al. Thermodynamic analysis of the influence of natural gas composition on H2S hydrogen production reaction. Petroleum and Natural Gas Chemical Industry, 2016, 45(6): 32-37).

[0004] Chinese invention patent application CN114471643A discloses a catalyst for hydrogen production through catalytic reforming of H2S and CH4 and its preparation method. The catalyst uses rare earth metal-modified alumina as a support and molybdenum oxide as the active component.

[0005] It is worth mentioning that acidic natural gas often contains CO2. For example, the high acidic gas fields in northeastern Sichuan have high levels of both H2S and CO2. The H2S content of natural gas in the Luojiazhai gas field is 8.78%–10.49% (volume fraction), and the CO2 content is 5.44%–10.41% (volume fraction). The CO2 content in natural gas in the Jilin oil field is even higher, reaching 26%–95% (volume fraction).

[0006] Under high-temperature reaction conditions, the reaction temperatures for catalytic reforming of natural gas to produce hydrogen or for catalytic reforming of H2S and CH4 to produce hydrogen are both above 600℃. At this temperature, CO2 and CH4 will also undergo reforming (mainly producing CO and H2), while CO2 and H2S will produce COS and H2O. Therefore, these natural gas components will engage in competitive reactions, which will not only affect their respective conversion rates but also change the types and composition of products, thus increasing the difficulty of product separation and purification, such as the separation and purification of hydrogen.

[0007] Chinese invention patent application CN114671404A discloses a supported MoS2 catalyst placed in a fixed-bed reactor. A mixed gas containing CH4, CO2, and H2S is introduced, and a reforming reaction is carried out at 700-800℃. It was found that the conversion rate of CH4 to CO2 is significantly improved in the presence of H2S compared to the case without H2S. However, this patent does not mention the conversion of H2S.

[0008] Currently, there is no catalytic process developed to produce hydrogen using H2S and CH4 from ultra-high sulfuric acid content natural gas as raw materials in the presence of CO2. Summary of the Invention

[0009] The purpose of this invention is to provide a molybdenum disulfide / aluminum silicate catalyst and its preparation method for hydrogen production through H2S and CH4 reforming in the presence of CO2. This catalyst promotes the reaction of H2S and CH4 to produce hydrogen and carbon disulfide (2H2S + CH4 → 4H2 + CS2, main reaction), while inhibiting the conversion of CO2 into other products such as CO (CO2 + CH4 → 2H2 + 2CO, side reaction) and COS (CO2 + H2S → COS + H2O, side reaction), thereby maximizing H2 yield (the main reaction yields the highest H2) while avoiding the conversion of easily separable and non-toxic CO2 in the feedstock into difficult-to-separate and toxic substances such as CO and COS. The successful development of this catalyst will contribute to the development and application of catalytic processes for hydrogen production through reforming of sulfuric acid-containing natural gas, especially ultra-high sulfuric acid-containing natural gas.

[0010] In a first aspect, the present invention provides a molybdenum disulfide / aluminum silicate catalyst, the catalyst comprising molybdenum disulfide and aluminum silicate, wherein the mass ratio of molybdenum disulfide to aluminum silicate is 1:9 to 9:1.

[0011] In one or more embodiments, the mass ratio of molybdenum disulfide to aluminum silicate is 2:8 to 8:2.

[0012] In one or more embodiments, the catalyst is Raschig ring-shaped, with an outer diameter of 3–8 mm, a wall thickness of 1–3 mm, and a height of 3–8 mm.

[0013] In one or more embodiments, the bulk density of the catalyst is 0.6 to 1.2 g / mL.

[0014] In one or more embodiments, the catalyst is composed of molybdenum disulfide and aluminum silicate.

[0015] A second aspect of the present invention provides a method for preparing the catalyst described in the first aspect of the present invention, the method comprising a ball milling mixing step and a melting step.

[0016] In one or more embodiments, the method includes the steps of:

[0017] (1) Molybdenum disulfide and aluminum silicate were ball-milled and mixed to obtain a mixed powder;

[0018] (2) The mixed powder is heated and melted at 800-1500°C, and then cooled to obtain the catalyst.

[0019] In one or more embodiments, in step (1), the particle size of molybdenum disulfide is 2 to 7 μm.

[0020] In one or more embodiments, in step (1), the particle size of molybdenum disulfide is 2.5 to 6.5 μm.

[0021] In one or more embodiments, in step (1), the particle size of aluminum silicate is 2–7 μm.

[0022] In one or more embodiments, in step (1), the particle size of aluminum silicate is 3 to 6 μm.

[0023] In one or more embodiments, ball milling is carried out for 6 to 24 hours.

[0024] In one or more embodiments, in step (2), the mixed powder is loaded into a mold and heated to melt.

[0025] In one or more embodiments, the mold is a Raschig ring mold.

[0026] In one or more embodiments, the mixed powder is compacted in the mold and then heated and melted.

[0027] In one or more embodiments, step (2) has one or more of the following features:

[0028] The heating and melting are carried out under the protection of a protective gas, which is one or more of nitrogen, helium and argon.

[0029] The flow rate of the protective gas is 30–300 mL / min;

[0030] The heating and melting process involves raising the temperature to 800-1500°C at a rate of 1-5°C / min.

[0031] The heating and melting process takes 1 to 10 hours.

[0032] After being heated to melt, it is cooled to 0-30℃.

[0033] In one or more embodiments, the heating and melting process takes place for 4 to 8 hours.

[0034] A third aspect of the present invention provides the application of the catalyst described in the first aspect of the present invention in the catalytic reforming of sulfuric acid-containing natural gas to produce hydrogen.

[0035] In one or more embodiments, the sulfuric acid-containing natural gas contains CO2, H2S, and CH4.

[0036] In one or more embodiments, the volume content of CO2 in the sulfuric acid-containing natural gas is ≤15%.

[0037] In one or more embodiments, the volume content of CO2 in the sulfuric acid-containing natural gas is 0.5% to 15%.

[0038] In one or more embodiments, the volume content of H2S in the sulfuric acid-containing natural gas is ≤80%.

[0039] In one or more embodiments, the sulfuric acid-containing natural gas contains 10% to 80% H2S by volume.

[0040] In one or more embodiments, the volume content of CH4 in the sulfuric acid-containing natural gas is 5% to 89.5%.

[0041] In one or more embodiments, the reforming for hydrogen production has one or more of the following features:

[0042] The reaction temperature is 800–1200℃;

[0043] Reaction pressure ≤ 0.5 MPa;

[0044] The volume hourly space velocity (VHSV) of the reactant gases is 1000–50000 h⁻¹ -1 ;

[0045] Before the reaction, a protective gas is introduced into the reactor. The protective gas is selected from one or more of nitrogen, helium, and argon, and the volume hourly space velocity of the protective gas is 4000–6000 h⁻¹. -1 ;

[0046] The catalyst is placed in a fixed-bed reactor for reaction. Attached Figure Description

[0047] Figure 1 This is an appearance diagram of the Raschig cyclic molybdenum disulfide / aluminum silicate catalyst obtained in Example 4. Detailed Implementation

[0048] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form preferred technical solutions.

[0049] The molybdenum disulfide / aluminum silicate catalyst of the present invention

[0050] This invention provides a molybdenum disulfide / aluminum silicate catalyst, comprising molybdenum disulfide and aluminum silicate, wherein the mass ratio of molybdenum disulfide to aluminum silicate can be 1:9 to 9:1, for example 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or 9:1. Preferably, the mass ratio of molybdenum disulfide to aluminum silicate is 2:8 to 8:2. The catalyst can be in the shape of a Raschig ring. The outer diameter of the Raschig ring catalyst can be 3 to 8 mm, the wall thickness can be 1 to 3 mm, and the height can be 3 to 8 mm. The outer diameter of the Raschig ring catalyst can be 4 mm, 5 mm, 6 mm, 7 mm, etc. The wall thickness of the Raschig ring catalyst can be 1.5 mm, 2 mm, 2.5 mm, etc. The height of the Raschig ring catalyst can be 4 mm, 5 mm, 6 mm, 7 mm, etc. In some embodiments, the outer diameter of the Raschig ring catalyst is the same as its height. The bulk density of the catalyst can be 0.6–1.2 g / mL, for example 0.7 g / mL, 0.8 g / mL, 0.9 g / mL, 1.0 g / mL, 1.1 g / mL, etc.

[0051] In some embodiments, the catalyst of the present invention is composed of molybdenum disulfide and aluminum silicate. The mass ratio of molybdenum disulfide to aluminum silicate is 1:9 to 9:1, for example, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, etc.

[0052] Preparation method of molybdenum disulfide / aluminum silicate catalyst

[0053] This invention provides a method for preparing a molybdenum disulfide / alumina silicate catalyst, comprising a ball milling mixing step and a melting step. In some embodiments, the method for preparing the molybdenum disulfide / alumina silicate catalyst includes the following steps:

[0054] (1) Molybdenum disulfide and aluminum silicate were ball-milled and mixed to obtain a mixed powder;

[0055] (2) The mixed powder is heated and melted at 1000-1200°C, and then cooled to obtain the catalyst of the present invention.

[0056] In step (1), the particle size of molybdenum disulfide can be 2–7 μm. Preferably, the particle size of molybdenum disulfide can be 2.5–6.5 μm, for example, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 6 μm, etc. The particle size of aluminum silicate can be 2–7 μm. Preferably, the particle size of aluminum silicate can be 3–6 μm, for example, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, etc. Molybdenum disulfide and aluminum silicate can be ball-milled and mixed in a mass ratio of 1:9 to 9:1, for example, a 1:9 ratio, a 1:8 ratio, a 1:7 ratio, a 7:1 ratio, an 8:1 ratio, or a 9:1 ratio. In some embodiments, molybdenum disulfide and aluminum silicate are placed in a ball mill jar and ball-milled and mixed in a mass ratio of 2:8 to 8:2. The ball milling process can be carried out for 6 to 24 hours, for example, 8 hours, 12 hours, or 18 hours.

[0057] In step (2), the mixed powder can be placed into a mold and heated to melt; preferably, the mold is a Raschig ring mold. In step (2), the mixed powder can be compacted before heating to melt; preferably, the mixed powder is placed into a mold, compacted, and then heated to melt. In step (2), the mixed powder can be first pressed into a Raschig ring shape and then heated to melt. In some embodiments, the mixed powder is compacted in a Raschig ring mold.

[0058] In step (2), the mixed powder can be heated and melted at 800–1500°C, for example, 900°C, 1100°C, 1300°C, 1400°C, etc. Preferably, the mixed powder is heated and melted at 1000–1200°C. During the heating and melting process, the temperature can be increased to 800–1500°C at a heating rate of 1–5°C / min. The heating rate can be 2°C / min, 3°C / min, 4°C / min, etc. The heating and melting can be carried out under the protection of a protective gas, which can be one or more of nitrogen, helium, and argon. The flow rate of the protective gas can be 30–300 mL / min, for example, 50 mL / min, 100 mL / min, 150 mL / min, 200 mL / min, 250 mL / min, etc. The heating and melting can be carried out for 1–10 hours, preferably 4–8 hours. After heating and melting, the powder is cooled to 0–30°C, for example, 5°C, 10°C, 20°C, 25°C. In some implementations, the material is heated to melt and then cooled to room temperature, such as 25°C.

[0059] In some embodiments, the molybdenum disulfide / aluminum silicate catalyst of the present invention is prepared by a method comprising the following steps:

[0060] (1) Molybdenum disulfide powder and aluminum silicate powder are loaded into a ball mill jar and mixed by ball milling for 6 to 24 hours to obtain mixed powder;

[0061] (2) Pour the mixed powder evenly into a mold, such as a Raschig ring mold, and compact the powder with a molding press. Then place the mold containing the powder into a high-temperature furnace and heat it to 1000-1200°C at a rate of 1-5°C / min under the protection of a protective gas, such as nitrogen, helium or argon, at a rate of 30-300 mL / min. Heat and melt for 4-8 hours. After cooling to room temperature, a molybdenum disulfide / aluminum silicate catalyst is obtained with a particle packing density of 0.6-1.2 g / mL.

[0062] Application of the molybdenum disulfide / aluminum silicate catalyst of the present invention in hydrogen production from sulfuric acid-containing natural gas reforming

[0063] The catalyst of this invention can be applied to hydrogen production through reforming sulfuric acid-containing natural gas. Sulfuric acid-containing natural gas contains CH4, H2S, and CO2. The volume content of H2S in the sulfuric acid-containing natural gas is ≤80%, for example, 5%, 10%, 20%, 30%, 40%, 60%, 70%, etc. The volume content of CO2 in the sulfuric acid-containing natural gas is ≤15%, for example, 0.3%, 0.5%, 1%, 5%, 8%, 12%, etc. The volume content of CH4 in the sulfuric acid-containing natural gas is ≥5%, for example, 10%, 20%, 30%, 50%, 70%, 80%, 89.5%, etc.

[0064] The reaction temperature for hydrogen production via reforming in this invention can be 800–1200°C, for example, 900°C, 1000°C, 1100°C, etc. The reaction pressure can be ≤0.5 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, etc. The reactant gas contains H₂S, CH₄, and CO₂. The volume content of CO₂ in the reactant gas can be 0.5–15%, for example, 1%, 3%, 5%, 10%, 12%, etc. The volume content of H₂S can be 10–80%, for example, 20%, 30%, 40%, 50%, 60%, 70%, etc. The volume content of CH₄ can be 5–89.5%, for example, 10%, 20%, 30%, 50%, 70%, 80%, etc. The sum of the volume contents of CO₂, H₂S, and CH₄ is ​​≤100%. The catalyst of this invention can be placed in a fixed-bed reactor for the reaction. The volume hourly space velocity (VHSV) of the reactant gases can be 1000–50000 h⁻¹. -1 For example, 2000h -1 5000h -1 10000h -1 20000h -1 30000h -1 40000h -1Before introducing the feed gas into the reactor, a protective gas can be introduced first. The protective gas can be selected from one or more of nitrogen, helium, and argon. In some embodiments, nitrogen is used as the protective gas. The volume hourly space velocity (VHSV) of the protective gas can be 4000–6000 h⁻¹. -1 Preferably 4500-5500h -1 .

[0065] In some embodiments, the method for producing hydrogen from sulfuric acid-containing natural gas using the catalyst of the present invention includes the following steps:

[0066] (1) Place the molybdenum disulfide / aluminum silicate catalyst in a reactor, such as a fixed-bed reactor, and introduce a protective gas, such as nitrogen, with a volume hourly space velocity of 4000-6000 h⁻¹. -1 For example, 5000h -1 The reactor was then heated to 800–1200°C and kept stable; the bed gas pressure was maintained at atmospheric pressure (≤0.5 MPa).

[0067] (2) Switch the protective gas to a feed gas containing H2S, CH4 and CO2, and adjust the gas volume hourly space velocity to 1000-50000 h⁻¹. -1 The hydrogen production reaction is carried out through reforming.

[0068] The advantages of this invention include:

[0069] (1) The catalyst preparation method of this invention is simple, and the catalyst raw materials and preparation costs are low. The raw materials used, molybdenum disulfide and aluminum silicate, are commercially available products with wide availability and low prices. The catalyst preparation adopts a simple mechanical mixing method and a molding and melting method, which is concise and easy for industrial production and application of catalysts.

[0070] (2) The preferred catalyst for molybdenum disulfide / aluminum silicate is Raschig ring, which has the characteristics of low pressure drop and fast mass transfer, and is particularly suitable for high-temperature fixed-bed reaction processes.

[0071] (3) The molybdenum disulfide / aluminum silicate catalyst exhibits good activity, selectivity, and hydrogen yield in the H2S and CH4 reforming hydrogen production process under CO2 conditions. Molybdenum disulfide is an important active component in the H2S and CH4 reforming hydrogen production process, but it also has certain activity for CO2 conversion. Aluminum silicate is a slightly acidic semi-metallic oxide with good chemical and high-temperature stability. After mixing micron-sized molybdenum disulfide powder and aluminum silicate powder by mechanical ball milling, the mixture is then heat-treated at high temperature (1000-1200℃). At this time, both substances are in a semi-molten state and can penetrate each other to form a homogeneous mixture with good particle interface bonding. In the catalyst of this invention, on the one hand, the molybdenum disulfide particles are in a highly dispersed state, which avoids the reduction of the number of active sites caused by particle growth. On the other hand, by introducing a low-activity and slightly acidic aluminosilicate structure at the highly active edge Mo-S bond, the adsorption and activation of acidic gas molecules CO2 are suppressed. The abundant lattice sulfur on the surface of the molybdenum disulfide particles provides active sites for activating CH bonds in CH4 and replacing S in H2S. Thus, the catalyst maintains high activity while improving selectivity and obtaining a high hydrogen yield.

[0072] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise stated, percentages and parts are by weight.

[0073] The molybdenum disulfide powder used in the embodiments and comparative examples of this invention has a particle size of 2.5–6.5 μm and a melting point of 1185 °C, and was purchased from Shandong Xinbaiyi Metal Materials Co., Ltd. The aluminum silicate powder used in the embodiments and comparative examples of this invention has a particle size of 3–6 μm and a melting point of 1260–1450 °C, and was purchased from Guangdong Xinxi Metallurgical Chemical Co., Ltd. The vertical planetary ball mill manufactured by Hunan Deco Instrument Equipment Co., Ltd. was used in the embodiments and comparative examples of this invention. The mold material used in the embodiments and comparative examples of this invention is graphite. The molding press used in the embodiments and comparative examples of this invention is a tablet press manufactured by Hongchen Machinery Technology (Dongguan) Co., Ltd. The high-temperature furnace used in the embodiments and comparative examples of this invention is a high-temperature box furnace manufactured by Shanghai Benting Instrument Co., Ltd.

[0074] In this invention, catalyst activity is expressed by the conversion rate of the feedstock H2S (or CH4), and is defined as follows:

[0075]

[0076] Molar flow rate refers to the number of moles of a specific gas molecule flowing through a cross-section per unit time. The molar flow rate of feedstock H2S is the number of moles of H2S flowing through a cross-section per unit time. The molar flow rate of feedstock CH4 is the number of moles of CH4 flowing through a cross-section per unit time. The molar flow rate of (feedstock-product) H2S is the number of moles of H2S in the feedstock gas flowing through a cross-section per unit time minus the number of moles of H2S in the product gas. The molar flow rate of (feedstock-product) CH4 is the number of moles of CH4 in the feedstock gas flowing through a cross-section per unit time minus the number of moles of CH4 in the product gas.

[0077] The higher the H2S (or CH4) conversion rate, the better the catalyst activity, and the more favorable it is for the H2S and CH4 reforming reaction to produce hydrogen.

[0078] In this invention, catalyst selectivity is defined as the percentage of CS2 produced relative to the total amount of carbonaceous compounds (including CO, COS, and CS2) produced, expressed as:

[0079]

[0080] The higher the catalyst selectivity, the stronger the competition between the main reaction H2S and the CH4 reforming hydrogen production process, and the weaker the competition between CO2 conversion.

[0081] In this invention, the catalyst hydrogen yield is defined as the percentage of product H2 generated to the total hydrogen content in the feedstock, expressed as:

[0082]

[0083] One mole of H2S contains the equivalent of one mole of H2 molecules, and one mole of CH4 contains the equivalent of two moles of H2 molecules.

[0084] The higher the hydrogen yield, the higher the hydrogen production efficiency of the reaction system, and the greater the industrial development and application value of the hydrogen production process from ultra-high sulfuric acid content natural gas reforming.

[0085] In this invention, the bulk density is measured and calculated according to the method described in the People's Republic of China Chemical Industry Standard, HG / T4680-2014, "Determination of Bulk Density of Fertilizer Catalysts".

[0086] Example 1 (Preparation of the catalyst)

[0087] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 3 μm and 6 μm, respectively, were weighed at a mass ratio of 2:8, mixed, and placed in a ball mill jar for 12 hours. The mixed powder was then poured evenly into a Raschig ring mold, compacted using a molding press, and the mold containing the powder was placed in a high-temperature furnace. Under nitrogen protection at a rate of 50 mL / min, the temperature was increased to 1000 °C at a rate of 3 °C / min, and the mixture was heated to melt for 8 hours. After cooling to room temperature, a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 3 mm, a wall thickness of 1 mm, and a height of 3 mm was obtained, with a catalyst particle bulk density of 0.9 g / mL.

[0088] Example 2 (Preparation of the catalyst)

[0089] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 6.5 μm and 3 μm, respectively, were weighed at a mass ratio of 8:2, mixed, and placed in a ball mill jar for 24 hours. The mixed powder was then poured evenly into a Raschig ring mold, compacted using a molding press, and the mold containing the powder was placed in a high-temperature furnace. Under argon protection at a rate of 300 mL / min, the temperature was increased to 1200 °C at a rate of 1 °C / min, and the mixture was heated to melt for 4 hours. After cooling to room temperature, a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 8 mm, a wall thickness of 3 mm, and a height of 8 mm was obtained, with a catalyst particle bulk density of 1.2 g / mL.

[0090] Example 3 (Preparation of the catalyst)

[0091] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 4 μm and 4 μm respectively were weighed at a mass ratio of 5:5, mixed, and placed in a ball mill jar for 6 hours. The mixed powder was then poured evenly into a Raschig ring mold, compacted using a molding press, and the mold containing the powder was placed in a high-temperature furnace. Under helium protection at a rate of 200 mL / min, the temperature was increased to 1100 °C at a rate of 5 °C / min and melted for 6 hours. After cooling to room temperature, a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 5 mm, a wall thickness of 2 mm, and a height of 5 mm was obtained, with a catalyst particle bulk density of 1.0 g / mL.

[0092] Example 4 (Preparation of the catalyst)

[0093] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 2.5 μm and 5.5 μm, respectively, were weighed at a mass ratio of 1:9, mixed, and placed in a ball mill jar for 16 hours. The mixed powder was then poured evenly into a Raschig ring mold, compacted using a molding press, and the mold containing the powder was placed in a high-temperature furnace. Under nitrogen protection at a rate of 100 mL / min, the temperature was increased to 1000 °C at a rate of 2 °C / min, and the mixture was heated to melt for 4 hours. After cooling to room temperature, a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 4 mm, a wall thickness of 1 mm, and a height of 4 mm was obtained, with a catalyst particle bulk density of 0.6 g / mL.

[0094] Comparative Example 1 (Preparation of catalyst, non-high-temperature melting, compared with Example 1)

[0095] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 3 μm and 6 μm, respectively, were weighed at a mass ratio of 2:8, mixed, and placed in a ball mill jar for 12 hours. The mixed powder was then poured evenly into a Raschig ring mold, compacted using a molding press, and the mold containing the powder was placed in a high-temperature furnace. Under nitrogen protection at a rate of 50 mL / min, the temperature was increased to 500 °C at a rate of 3 °C / min and heated for 8 hours. After cooling to room temperature, a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 3 mm, a wall thickness of 1 mm, and a height of 3 mm was obtained, with a catalyst particle bulk density of 0.8 g / mL.

[0096] Comparative Example 2 (Catalyst preparation, non-ball milling mixing, compared with Example 1)

[0097] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 3μm and 6μm, respectively, were weighed at a mass ratio of 2:8. After being manually mixed, the powder was poured evenly into a Raschig ring mold and compacted using a molding press. The mold containing the powder was then placed in a high-temperature furnace and heated to 1000℃ at a rate of 3℃ / min under nitrogen protection at a rate of 50mL / min. The mixture was melted for 8 hours and then cooled to room temperature to obtain a Raschig ring molybdenum disulfide / aluminum silicate catalyst with an outer diameter of 3mm, a wall thickness of 1mm, and a height of 3mm. The bulk density of the catalyst particles was 0.9g / mL.

[0098] Comparative Example 3 (Catalyst preparation, non-Raschig ring mold, compared with Example 1)

[0099] Commercially available molybdenum disulfide and aluminum silicate powders with particle sizes of 3 μm and 6 μm, respectively, were weighed at a mass ratio of 2:8, mixed, and placed in a ball mill jar for 12 hours. The mixed powder was then poured evenly into a cylindrical mold and compacted using a molding press. The mold containing the powder was then placed in a high-temperature furnace and heated to 1000°C at a rate of 3°C / min under nitrogen protection at a rate of 50 mL / min, and melted for 8 hours. After cooling to room temperature, a cylindrical molybdenum disulfide / aluminum silicate catalyst with a diameter of 3 mm and a height of 3 mm was obtained, with a catalyst particle bulk density of 2.8 g / mL.

[0100] Example 5 (Catalytic Reaction)

[0101] The catalysts prepared in Examples 1-4 and Comparative Examples 1-3 were placed in fixed-bed reactors, and nitrogen gas was introduced at a volume hourly space velocity of 5000 h⁻¹. -1 The fixed-bed reactor was then heated to the required temperature and kept stable, with the bed gas pressure maintained at atmospheric pressure (≤0.5MPa). The nitrogen gas was then switched to a feed gas containing H2S, CH4, and CO2, and the volumetric space velocity of the feed gas was adjusted to 1000–50000 h⁻¹. -1 The volume content of CO2 was 0.5-15%, H2S was 10-80%, and CH4 was 5-89.5%. The flow rate of the reactor outlet gas was measured by a flow meter, and the contents of the raw material H2S, CH4 gas and products H2, CO, COS, CS2 and other substances in the reactor outlet gas were detected by gas chromatography. The raw material conversion rate, selectivity and hydrogen yield were calculated (for analytical methods, see: Su Hui, et al., Journal of Energy Chemistry, 25(2016)110-116). The results are listed in Table 1 below.

[0102] It is evident that, under the same reaction conditions, the comparative catalyst not only showed a significant decrease in the conversion rates of the feedstocks H2S and CH4, but also a marked reduction in catalyst selectivity and hydrogen yield. The molybdenum disulfide / aluminum silicate catalyst of this invention exhibits excellent catalytic performance in the reforming of sulfuric acid-containing natural gas for hydrogen production. Preparing this catalyst in a Raschig ring configuration further enhances its catalytic performance.

[0103] Table 1: Reaction results of the catalysts prepared in Examples 1-4 and Comparative Examples 1-3

[0104]

Claims

1. A method for preparing a molybdenum disulfide / aluminum silicate catalyst, characterized in that, The method includes the following steps: (1) Molybdenum disulfide and aluminum silicate were ball-milled and mixed to obtain a mixed powder; (2) The mixed powder is heated to semi-melt at 1000~1200 °C, and then cooled to obtain the catalyst; The molybdenum disulfide / aluminum silicate catalyst comprises molybdenum disulfide and aluminum silicate, with a mass ratio of molybdenum disulfide to aluminum silicate of 1:9 to 9:

1.

2. The method as described in claim 1, characterized in that, In step (1), the particle size of molybdenum disulfide is 2~7 μm, the particle size of aluminum silicate is 2~7 μm, and / or, ball milling is carried out for 6~24 h.

3. The method as described in claim 2, characterized in that, In step (1), the particle size of molybdenum disulfide is 2.5~6.5 mm. m.

4. The method as described in claim 2, characterized in that, In step (1), the particle size of aluminum silicate is 3~6. m.

5. The method as described in claim 1, characterized in that, In step (2), the mixed powder is loaded into a mold and heated until it is semi-molten.

6. The method as described in claim 5, characterized in that, In step (2), the mold is a Raschig ring mold.

7. The method as described in claim 5, characterized in that, In step (2), the mixed powder is compacted in the mold and then heated to semi-melt.

8. The method as described in claim 1, characterized in that, Step (2) has one or more of the following characteristics: The heating to semi-melt is carried out under the protection of a protective gas, which is one or more of nitrogen, helium and argon. The flow rate of the protective gas is 30~300 mL / min; The heating to semi-melt is carried out at a heating rate of 1~5 °C / min to 1000~1200 °C; The heating process to semi-melt is carried out for 1-10 hours; Heat to semi-melt and then cool to 0~30℃.

9. The method as described in claim 1, characterized in that, The heating process to semi-melt takes 4-8 hours.

10. The molybdenum disulfide / aluminum silicate catalyst prepared by any one of claims 1-9.

11. The molybdenum disulfide / aluminum silicate catalyst as described in claim 10, characterized in that, The mass ratio of molybdenum disulfide to aluminum silicate is 2:8 to 8:

2.

12. The molybdenum disulfide / aluminum silicate catalyst as described in claim 10, characterized in that, The molybdenum disulfide / aluminum silicate catalyst is Raschig ring-shaped, with an outer diameter of 3-8 mm, a wall thickness of 1-3 mm, and a height of 3-8 mm.

13. The molybdenum disulfide / aluminum silicate catalyst as described in claim 10, characterized in that, The molybdenum disulfide / aluminum silicate catalyst has a bulk density of 0.6~1.2 g / mL.

14. The molybdenum disulfide / aluminum silicate catalyst as described in claim 10, characterized in that, The molybdenum disulfide / aluminum silicate catalyst is composed of molybdenum disulfide and aluminum silicate.

15. The application of the molybdenum disulfide / aluminum silicate catalyst according to any one of claims 10-14 in the catalytic reforming of sulfuric acid-containing natural gas to produce hydrogen.

16. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas contains CO2, H2S and CH4.

17. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas has a CO2 volume content of ≤15%.

18. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas contains 0.5% to 15% CO2 by volume.

19. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas has a volume content of H2S ≤ 80%.

20. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas contains 10% to 80% H2S by volume.

21. The application as described in claim 15, characterized in that, The sulfuric acid-containing natural gas contains CH4 at a volume content of 5% to 89.5%.

22. The application as described in claim 15, characterized in that, The reforming hydrogen production has one or more of the following characteristics: The reaction temperature is 800~1200 ℃; Reaction pressure 0.5 MPa; The volume hourly space velocity (VHSV) of the reactant gases is 1000–50000 h⁻¹ -1 ; Before the reaction, a protective gas is introduced into the reactor. The protective gas is selected from one or more of nitrogen, helium, and argon, and the volume hourly space velocity of the protective gas is 4000~6000 h⁻¹. -1 ; The catalyst is placed in a fixed-bed reactor for reaction.

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