Sulfur-tolerant shift predeformation protective agent as well as preparation method and application thereof

Abstract

The invention provides a sulfur-tolerant shift pre-transformation protective agent as well as a preparation method and application thereof, and relates to the technical field of sulfur-tolerant shift. The magnesium aluminate spinel, the nickel aluminate spinel and the activated carbon are used as composite carriers, the cobalt is used as a main conversion active component, the detoxification carriers have good adsorption and removal effects on arsenic compounds and small-particle impurities, the arsenic capacity is large and is not influenced by the content of hydrogen sulfide, the conversion activity of the protective agent is moderate, the temperature rise of a bed layer is controllable, and the conditions of large temperature rise and overtemperature are avoided; the influence of a water-carrying working condition on the catalyst is greatly avoided, and the catalyst is suitable for a pre-shift furnace and a detoxification tank in a sulfur-tolerant shift process.

Description

Technical Field

[0001] The present invention relates to the technical field of sulfur-tolerant shift for producing chemical raw materials such as syngas, hydrogen, and methanol from heavy raw materials such as coal and petroleum coke, and particularly relates to a sulfur-tolerant shift pre-change protective agent, a preparation method thereof, and an application thereof. Background Art

[0002] With the development of coal gasification technology, its adaptability to coal types is getting stronger and stronger. As a result, in addition to main gases such as CO, CO2, and H2 in coal-derived syngas, it also contains various impurities, such as trace amounts of O2, organic sulfides, arsenides, HCN, and heavy metals. These impurities and their contents vary with different coal types. These impurities all have a certain impact on the normal use of sulfur-tolerant shift catalysts. Among them, arsenic and its compounds have been proven to seriously affect the catalyst activity and activity stability, and need to be removed or transformed. At present, the arsenic removers on the market are mostly used for arsenic removal in oil products and exhaust gas, and there are many types. Most of them are for arsenic removal treatment by loading active components on carriers. However, due to different working environments for arsenic removal, their compositions are also different. The active components can be selected from metal oxides, such as copper-based, nickel-based, molybdenum-based, manganese-based, lead-based, etc. The carriers can be selected from activated carbon, porous amorphous magnesium aluminum crystallite, etc. Chinese Patent CN105536689A discloses a supported arsenic remover and a preparation method thereof. The supported arsenic remover uses porous amorphous magnesium aluminum crystallite as the carrier and CuO and / or NiO as the active components. The supported arsenic remover has the advantages of large adsorption capacity, high arsenic removal rate, and high stability. However, its arsenic capacity is greatly affected by the sulfur content, and NiO is prone to generate nickel carbonyl under the conditions of high CO atmosphere and 200-300 °C, resulting in pipeline blockage and an increase in the device pressure difference, affecting subsequent production.

[0003] At present, the sulfur-tolerant shift process design mostly adopts the route of detoxification tank + multi-stage shift. The detoxification tank is filled with protective agents, and the protective agents are mostly alumina, magnesium aluminate spinel, or silicon-aluminum compounds, etc. These protective agents do not contain active components and have certain functions such as detoxification, ash blocking, and preventing water carry-over. However, from the actual industrial application effect, the removal effect of these protective agents on heavy metal poisons such as arsenic is very poor, and they cannot play the role of detoxification protection. Some devices use cobalt-molybdenum-based or nickel-molybdenum-based sulfur-tolerant shift protective agents with shift activity. Although this method can improve the arsenic removal protection effect, there are also problems such as low poison capacity and fast breakthrough, and due to its unstable shift activity and high initial activity, it brings great difficulties to device design and stable operation, directly affecting the safe, stable, and economic operation of the device. Summary of the Invention

[0004] In view of the above problems, the present invention provides a sulfur-tolerant shift pre-shift protective agent, a preparation method thereof, and an application thereof. The method of the present invention forms a pre-shift protective agent with magnesium aluminate spinel, nickel aluminate spinel, and activated carbon as carriers and cobalt as the main shift active component. Through the modification of activated carbon, the pore structure of the carrier is improved, and through the synergistic cooperation of the pores in the carrier and nickel aluminate spinel, the function of removing metal poisons is achieved; and the main shift active component cobalt has moderate shift activity and is suitable for the pre-shift furnace and detoxification tank in the sulfur-tolerant shift process. The pre-shift protective agent has a good adsorption and removal effect on arsenic compounds and small particle impurities, has a large arsenic capacity, is not affected by the hydrogen sulfide content, and has appropriate shift activity, enabling its bed layer to have a certain temperature rise and avoiding the influence of water-carrying conditions on the catalyst.

[0005] One of the purposes of the present invention is to provide a preparation method of a sulfur-tolerant shift pre-shift protective agent.

[0006] Another purpose of the present invention is to provide a sulfur-tolerant shift pre-shift protective agent prepared by the preparation method.

[0007] A third purpose of the present invention is to provide an application of the sulfur-tolerant shift pre-shift protective agent.

[0008] In order to achieve the above purposes of the present invention, the following technical solutions are specifically adopted:

[0009] In the first aspect, the present invention provides a preparation method of a sulfur-tolerant shift pre-shift protective agent, including the following steps:

[0010] S1. Dissolve nickel salt and citric acid in deionized water and stir evenly to obtain solution A;

[0011] S2. Mix the aluminum compound powder, magnesium compound powder, and activated carbon powder evenly, add solution A, knead evenly, extrude into shape, air-dry naturally, and calcine in an oxygen-free environment to form a detoxification carrier;

[0012] S3. Dissolve cobalt salt in deionized water to form impregnation solution B, impregnate the detoxification carrier with solution B in an equal volume, dry, and then calcine in an oxygen-free environment to obtain the pre-shift protective agent.

[0013] Step S1:

[0014] In some embodiments, in step S1, the nickel salt is one or more selected from nickel nitrate and nickel acetate.

[0015] In some embodiments, in step S1, the addition amount of the nickel salt calculated as nickel oxide is 4%-9% of the mass of the sulfur-tolerant shift pre-shift protective agent.

[0016] In some embodiments, in step S1, the addition amount of citric acid is 4%-10% of the mass of the sulfur-tolerant shift pre-shift protective agent.

[0017] Step S2:

[0018] In some embodiments, in step S2, the aluminum-containing compound is one or more selected from pseudoboehmite and aluminum gel, the magnesium-containing compound is light magnesium oxide, the activated carbon is one or more selected from fruit shell activated carbon and coconut shell activated carbon, and the specific surface area is 300 - 400 m 2 / g.

[0019] In some embodiments, in step S2, the addition amount of the aluminum-containing compound calculated as aluminum oxide is 45% - 55% of the mass of the sulfur-tolerant shift pre-shift protective agent, and the addition amount of the magnesium-containing compound calculated as magnesium oxide is 12% - 18% of the mass of the sulfur-tolerant shift pre-shift protective agent; and the molar ratio of magnesium oxide to aluminum oxide is 1:1.25 - 1.45; the addition amount of the activated carbon is 10% - 25% of the mass of the sulfur-tolerant shift pre-shift protective agent.

[0020] In some embodiments, in step S2, the calcination temperature is 650 - 750 °C and the calcination time is 3 - 6 h.

[0021] Calcining at this temperature to form a composite support of magnesium aluminate spinel, nickel aluminate spinel and activated carbon.

[0022] Step S3:

[0023] In some embodiments, in step S3, the cobalt salt is one or more selected from cobalt nitrate and cobalt acetate.

[0024] In some embodiments, in step S3, the addition amount of the cobalt salt calculated as cobalt oxide is 6% - 15% of the mass of the sulfur-tolerant shift pre-shift protective agent.

[0025] Test the water absorption rate of the detoxified support obtained in step S2. The water absorption rate of the detoxified support is 50% - 60%. The amount of deionized water is the volume amount equal to the volume of the detoxified support impregnated (for example, when the water absorption rate is 55%, take 100 g of the support and dissolve the calculated cobalt nitrate in 55 mL of deionized water for impregnation).

[0026] In some embodiments, in step S3, the calcination temperature is 420 - 480 °C and the calcination time is 2 - 4 h.

[0027] In a second aspect, the present invention provides a sulfur-tolerant shift pre-shift protective agent prepared by the above preparation method, including a detoxified support and a cobalt oxide component on the detoxified support, wherein the detoxified support is a composite support of magnesium aluminate spinel, nickel aluminate spinel and activated carbon.

[0028] The mass percentages of the components in the sulfur-tolerant shift pre-reforming protective agent are as follows: cobalt oxide 6%-15%, nickel oxide 4%-9%, alumina 45%-55%, magnesia 12%-18%, activated carbon 10%-25%; and the molar ratio of magnesia to alumina is 1:1.25-1.45.

[0029] Thirdly, the present invention provides an application of the above sulfur-tolerant shift pre-reforming protective agent in the water gas shift reaction.

[0030] For the finished pre-reforming protective agent, at an inlet temperature of 220-280°C, a pressure of 2.0-6.0 MPa, a water / gas ratio of 0.5-1.5, and a dry gas space velocity of 3000-5000 h -1 Under these conditions, the CO conversion activity is 5%-30%.

[0031] The pre-reforming protective agent of the present invention uses a composite support of magnesium aluminate spinel, nickel aluminate spinel and activated carbon, which has strong anti-hydration ability and stable structure. After the activated carbon is modified, it is rich in mesopores, greatly improving the ability of the support structure to accommodate heavy metal small particle impurities. Nickel forms a nickel aluminate spinel structure with the alumina component in the support. Nickel has a good removal effect on metal hydrides such as arsenic, and the formation of the nickel aluminate spinel structure can greatly reduce the formation of nickel carbonyl compounds by nickel metal under the pre-reforming process conditions, ensuring its stable performance. At the same time, nickel also provides a certain conversion activity (moderate) with the active component cobalt, making the temperature rise of the protective agent bed controllable, and there will be no large temperature rise and over-temperature conditions, which is suitable for the pre-reforming furnace and detoxification tank in the sulfur-tolerant shift process.

[0032] Beneficial effects:

[0033] The preparation method of the pre-reforming protective agent involved in the present invention is simple, easy to implement, the active components have good dispersion, the conversion activity is moderate, the temperature rise of the bed is controllable, the CO conversion activity does not exceed 30%, and there will be no large temperature rise and over-temperature conditions. At the same time, it greatly avoids the influence of the water-carrying condition on the catalyst, and is suitable for the pre-reforming furnace and detoxification tank in the sulfur-tolerant shift process. At the same time, it has a good adsorption and removal effect on arsenic compounds and small particle impurities, has a large arsenic adsorption capacity, and is not affected by the hydrogen sulfide content, which is conducive to the safe and stable operation of the device, and has good economic benefits and application prospects.

[0034] The present invention has been described in detail above, but the above embodiments are essentially illustrative only and are not intended to limit the present invention. In addition, the present invention is not limited by any theory described in the foregoing prior art or the invention content or the following examples. Description of the drawings

[0035] Figure 1 It is a schematic flow diagram of the pressurized evaluation device;

[0036] Reference numerals: 1 - raw gas purifier; 2 - pressure reducer; 3 - mixer; 4 - pressure gauge; 5 - shutdown valve; 6 - heating furnace; 7 - reaction tube; 8 - internal heat thermocouple tube; 9 - condenser; 10 - separator; 11 - drainer; 12 - wet gas meter; 13 - vaporizer; 14 - water tank; 15 - water metering pump. Detailed implementation mode

[0037] The present invention will be further described below in conjunction with embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation to the scope of protection claimed by the present invention.

[0038] Unless otherwise specified, the raw materials, reagents, methods, etc. used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0039] Embodiment 1

[0040] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, stir evenly to obtain solution A; mix 65.7 g of pseudoboehmite powder, 14 g of light magnesium oxide powder and 20 g of coconut shell activated carbon powder with a specific surface area of 350 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 700 °C for 4 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of the detoxification carrier is 55%, dissolve 48 g of cobalt nitrate hexahydrate in 55 mL of deionized water, pour the detoxification carrier into the solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 460 °C for 3 h to obtain the finished pre-reforming protective agent CAT1.

[0041] Embodiment 2

[0042] Dissolve 15.5 g of nickel nitrate hexahydrate and 10 g of citric acid in 30 mL of deionized water, stir evenly to obtain solution A; mix 64.2 g of pseudoboehmite powder, 13 g of light magnesium oxide powder and 24 g of fruit shell activated carbon powder with a specific surface area of 300 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 650 °C for 6 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of the detoxification carrier is 53%, dissolve 56 g of cobalt nitrate hexahydrate in 53 mL of deionized water, pour the detoxification carrier into the solution for equal-volume impregnation, dry at 105 °C, and calcine in a nitrogen atmosphere at 420 °C for 5 h to obtain the finished pre-reforming protective agent CAT2.

[0043] Embodiment 3

[0044] Dissolve 34.9 g of nickel nitrate hexahydrate and 17 g of citric acid in 45 mL of deionized water, and stir evenly to obtain solution A; mix 110 g of aluminum hydroxide gel powder, 18 g of light magnesium oxide powder and 17 g of coconut shell activated carbon powder with a specific surface area of 400 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air-dry naturally, and calcine in a nitrogen atmosphere at 750 °C for 3 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 52%. Dissolve 32 g of cobalt nitrate hexahydrate in 52 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 120 °C, and calcine in a nitrogen atmosphere at 480 °C for 3 h to obtain the finished product pre-change protection agent CAT3.

[0045] Example 4

[0046] Dissolve 23.2 g of nickel nitrate hexahydrate and 14 g of citric acid in 35 mL of deionized water, and stir evenly to obtain solution A; mix 77.1 g of pseudo-boehmite powder, 15 g of light magnesium oxide powder and 15 g of coconut shell activated carbon powder with a specific surface area of 360 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air-dry naturally, and calcine in a nitrogen atmosphere at 680 °C for 5 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 50%. Dissolve 40 g of cobalt nitrate hexahydrate in 50 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 100 °C, and calcine in a nitrogen atmosphere at 440 °C for 4 h to obtain the finished product pre-change protection agent CAT4.

[0047] Example 5

[0048] Dissolve 19.4 g of nickel nitrate hexahydrate and 15 g of citric acid in 35 mL of deionized water, and stir evenly to obtain solution A; mix 78.5 g of pseudo-boehmite powder, 16 g of light magnesium oxide powder and 15 g of coconut shell activated carbon powder with a specific surface area of 320 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air-dry naturally, and calcine in a nitrogen atmosphere at 720 °C for 3 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 51%. Dissolve 36 g of cobalt nitrate hexahydrate in 51 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 450 °C for 4 h to obtain the finished product pre-change protection agent CAT5.

[0049] Comparative Example 1

[0050] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, and stir evenly to obtain solution A; mix 65.7 g of pseudoboehmite powder, 14 g of light magnesium oxide powder and 20 g of coconut shell activated carbon powder with a specific surface area of 350 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 500 °C for 4 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 58%. Dissolve 48 g of cobalt nitrate hexahydrate in 58 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 460 °C for 3 h to isolate oxygen to obtain the finished product pre-change protection agent DAT1.

[0051] Comparative Example 2

[0052] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, and stir evenly to obtain solution A; mix 78.6 g of pseudoboehmite powder, 17 g of light magnesium oxide powder and 8 g of coconut shell activated carbon powder with a specific surface area of 350 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 700 °C for 4 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 22%. Dissolve 48 g of cobalt nitrate hexahydrate in 22 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 110 °C, the active components are enriched on the surface of the pre-change protection agent, and the impregnation effect is poor. Calcine in a nitrogen atmosphere at 460 °C for 3 h to isolate oxygen to obtain the finished product pre-change protection agent DAT2.

[0053] Comparative Example 3

[0054] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, and stir evenly to obtain solution A; mix 57.1 g of pseudoboehmite powder, 20 g of light magnesium oxide powder and 20 g of coconut shell activated carbon powder with a specific surface area of 350 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 700 °C for 4 h to isolate oxygen to form a detoxification carrier. Test that the water absorption rate of this detoxification carrier is 55%. Dissolve 48 g of cobalt nitrate hexahydrate in 55 mL of deionized water, pour the detoxification carrier into this solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 460 °C for 3 h to isolate oxygen to obtain the finished product pre-change protection agent DAT3.

[0055] Comparative Example 4

[0056] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, and stir evenly to obtain solution A; mix 65.7 g of pseudoboehmite powder, 14 g of light magnesium oxide powder and 20 g of coconut shell activated carbon powder with a specific surface area of 200 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 700 °C for 4 h to isolate oxygen to form a detoxification carrier. The water absorption rate of the detoxification carrier is tested to be 46%. Dissolve 48 g of cobalt nitrate hexahydrate in 46 mL of deionized water, pour the detoxification carrier into the solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 460 °C for 3 h to isolate oxygen to obtain the finished product pre-shift protection agent DAT4.

[0057] Comparative Example 5

[0058] Dissolve 31 g of nickel nitrate hexahydrate and 20 g of citric acid in 40 mL of deionized water, and stir evenly to obtain solution A; mix 75.7 g of pseudoboehmite powder and 20 g of coconut shell activated carbon powder with a specific surface area of 350 m 2 / g evenly, add solution A, knead evenly, extrude into strips with a diameter of 3 mm, air dry naturally, and calcine in a nitrogen atmosphere at 700 °C for 4 h to isolate oxygen to form a detoxification carrier. The water absorption rate of the detoxification carrier is tested to be 60%. Dissolve 48 g of cobalt nitrate hexahydrate in 60 mL of deionized water, pour the detoxification carrier into the solution for equal-volume impregnation, dry at 110 °C, and calcine in a nitrogen atmosphere at 460 °C for 3 h to isolate oxygen to obtain the finished product pre-shift protection agent DAT5.

[0059] Figure 1 It is a pressurized activity evaluation device, which is used to simulate the industrial application conditions of the pre-shift furnace, determine the changes in the tail gas of the catalyst under different conditions, and compare the comprehensive performance of the catalyst. The reaction tube is a 316L stainless steel tube with a thermocouple tube in the center. According to the requirements of different steam-gas ratios, a certain amount of water is added, gasified at high temperature, and then enters the reaction tube together with the raw material gas for the water-gas shift reaction. The tail gas after the reaction is analyzed by chromatography.

[0060] Loading amount of sulfur-tolerant shift pre-shift protection agent: 50 mL;

[0061] Composition of raw material gas A: CO concentration 50% (v / v); H2S concentration 0.2% (v / v); the rest is H2.

[0062] Composition of raw material gas B: CO concentration 50% (v / v); H2S concentration 0.2% (v / v); AsH3 concentration 0.5% (v / v); the rest is H2.

[0063] The evaluation process is as follows: After the nitrogen leak test is qualified, the system pressure is stabilized at 4.0 MPa, the bed temperature is raised to 250 °C at a heating rate of 50 °C / h, the feed gas is switched, and after maintaining a constant temperature for 10 minutes, the evaluation is carried out using feed gas A. The evaluation conditions are: temperature 250 °C; pressure 4.0 MPa; dry gas hourly space velocity 3000 h -1 ; steam-gas ratio 1.0; time 10 h. The average value of the CO conversion rate at 5 - 10 h is taken as the initial activity of the catalyst. Then, the feed gas B is switched for testing, and the testing conditions remain unchanged, with a time of 40 h.

[0064] Adopt Figure 1 The pressurized activity evaluation device and evaluation conditions are used to conduct a pressurized activity test on the pre-reforming protective agents of the examples and comparative examples under the process conditions of the simulated pre-reforming furnace. The side pressure strength is measured using a DL-II type particle strength tester and is measured according to the HG / T 2782 standard. The phase structure is determined on a Smartlab3 type X-ray diffractometer produced by Rigaku Corporation of Japan. The scanning range is 10° - 70°, and the scanning speed is 10° / min. The results are shown in Table 1.

[0065] Table 1 Test results of pre-reforming protective agents with different numbers

[0066] Number Side pressure strength (N / cm) Phase structure (fresh sample) CO conversion rate, % CAT1 133 <![CDATA[NiAl2O4 / MgAl2O4]]> 22.5 CAT 2 130 <![CDATA[NiAl2O4 / MgAl2O4]]> 22.4 CAT 3 131 <![CDATA[NiAl2O4 / MgAl2O4]]> 22.3 CAT 4 129 <![CDATA[NiAl2O4 / MgAl2O4]]> 22.0 CAT 5 128 <![CDATA[NiAl2O4 / MgAl2O4]]> 22.1 DAT1 125 <![CDATA[NiO / Al2O3 / MgAl2O4]]> 42.0 DAT 2 86 <![CDATA[NiAl2O4 / MgAl2O4]]> 14.0 DAT 3 126 <![CDATA[NiO / NiAl2O4 / MgO / MgAl2O4]]> 41.5 DAT 4 130 <![CDATA[NiAl2O4 / MgAl2O4]]> 18.2 DAT 5 135 <![CDATA[NiAl2O4 / Al2O3]]> 20.2

[0067] Adopt Figure 1 The pressurized activity evaluation device and evaluation conditions are used. The pre-reforming protective agents of the examples and comparative examples are tested according to the evaluation process. The nickel content and As content in the pre-reforming protective agents are detected by XRF. The comparison of the nickel content between the unloaded sample and the fresh sample is the nickel retention rate. The results are shown in Table 2.

[0068] Table 2 Detection results after evaluating catalysts with different numbers

[0069]

[0070]

[0071] Result analysis:

[0072] The phase structure of the sulfur-resistant shift pre-shift protective agent carrier prepared by the present invention is NiAl2O4 / MgAl2O4. After being modified with a certain amount and specific surface area of activated carbon, it is rich in mesopores. The obtained pre-shift protective agent has a moderate CO conversion rate, a high nickel retention rate in the sample after reaction, and a high arsenic poison adsorption capacity. In Comparative Example 1, it was calcined at a low temperature of 500 °C, and the nickel aluminate spinel structure was not formed. The structural stability of alumina was poor. After use, AlOOH was generated, and the nickel retention rate was low. In Comparative Example 2, the content of activated carbon was small, which had a great impact on the pore structure, resulting in a low water absorption rate of the carrier, poor impregnation effect, low shift activity, and poor detoxification effect. In Comparative Example 3, the molar ratio of aluminum to magnesium was 0.8, which was inappropriate. There were free magnesium oxide and nickel oxide phases. The shift activity was higher than 30%, and the nickel stability and arsenic absorption capacity decreased. In Comparative Example 4, activated carbon with a low specific surface area was used, resulting in a low shift activity and a poor detoxification effect. In Comparative Example 5, it did not contain magnesium aluminate spinel, and the structural stability of the carrier was poor. AlOOH was generated. The unstable structure and the generation of AlOOH would cause changes in the pore structure, affecting the activity and detoxification performance of the catalyst.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: within the scope not departing from the spirit and essence defined by the claims of the present invention, the technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and these modifications or replacements are still within the scope defined by the claims of the present invention.

Claims

1. A preparation method of a sulfur-tolerant shift pre-shift protective agent, characterized in that, It includes the following steps: S1. Dissolve nickel salt and citric acid in deionized water, and stir evenly to obtain solution A; S2. Mix the aluminum compound powder, magnesium compound powder and activated carbon powder evenly, add solution A, knead evenly, extrude into shape, dry naturally, roast in an oxygen-free environment to form a detoxification carrier; S3. Dissolve cobalt salt in deionized water to form impregnation solution B. Impregnate the detoxification carrier with solution B in an equal volume, dry and then roast in an oxygen-free environment to obtain a pre-transforming protective agent.

2. The preparation method according to claim 1, characterized in that, In step S1, the nickel salt is one or more selected from nickel nitrate and nickel acetate.

3. The preparation method according to claim 1, wherein, In step S1, the addition amount of the nickel salt calculated as nickel oxide is 4%-9% of the mass of the sulfur-tolerant shift pre-transforming protective agent.

4. The preparation method according to claim 1, wherein In step S2, the aluminum-containing compound is one or more selected from pseudo-boehmite and aluminum gel, the magnesium-containing compound is light magnesium oxide, the activated carbon is one or more selected from fruit shell activated carbon and coconut shell activated carbon, and the specific surface area is 300-400m 2 / g.

5. The preparation method according to claim 1, characterized in that, In step S2, the addition amount of the aluminum compound calculated as aluminum oxide is 45%-55% of the mass of the sulfur-tolerant shift pre-transforming protective agent, and the addition amount of the magnesium compound calculated as magnesium oxide is 12%-18% of the mass of the sulfur-tolerant shift pre-transforming protective agent; and the molar ratio of magnesium oxide to aluminum oxide is 1:1.25-1.45; the addition amount of activated carbon is 10%-25% of the mass of the sulfur-tolerant shift pre-transforming protective agent.

6. The preparation method according to claim 1, characterized in that, In step S2, the roasting temperature is 650-750°C, and the roasting time is 3-6h.

7. The preparation method according to claim 1, wherein In step S3, the cobalt salt is one or more selected from cobalt nitrate and cobalt acetate; The addition amount of the cobalt salt calculated as cobalt oxide is 6%-15% of the mass of the sulfur-tolerant shift pre-transforming protective agent.

8. The preparation method according to claim 1, characterized in that, In step S3, the roasting temperature is 420-480°C, and the roasting time is 2-4h.

9. A sulfur-tolerant shift pre-shift protective agent, characterized in that, Prepared by the preparation method according to any one of claims 1-8; the sulfur-tolerant shift pre-transforming protective agent includes a detoxification carrier and a cobalt oxide component on the detoxification carrier, wherein the detoxification carrier is a composite carrier of magnesium aluminate spinel, nickel aluminate spinel and activated carbon.

10. Application of the sulfur-tolerant shift pre-transforming protective agent according to claim 9 in the water gas shift reaction.

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