CN111085189A

CN111085189A - Sulfur-tolerant shift methanation bifunctional catalyst and preparation method thereof

Info

Publication number: CN111085189A
Application number: CN201811243250.2A
Authority: CN
Inventors: 白志敏; 赵庆鲁; 余汉涛; 李文柱; 田兆明; 齐焕东; 王昊; 姜建波; 薛红霞; 陈依屏
Original assignee: China Petroleum and Chemical Corp; Qilu Petrochemical Co of Sinopec
Current assignee: China Petroleum and Chemical Corp; Qilu Petrochemical Co of Sinopec
Priority date: 2018-10-24
Filing date: 2018-10-24
Publication date: 2020-05-01
Anticipated expiration: 2038-10-24
Also published as: CN111085189B

Abstract

The invention belongs to the field of sulfur tolerant shift and methanation reactions, and particularly relates to a sulfur tolerant shift methanation bifunctional catalyst, and a preparation method and application thereof. According to the preparation method of the catalyst provided by the invention, the oxides of Al, Si and Ba in the carrier are mainly from the waste catalytic cracking catalyst, the waste catalytic cracking catalyst can partially replace the commonly used alumina or aluminum-containing compound in the bifunctional catalyst after being treated, and meanwhile, the titanium-containing compound is added by adopting a proper method, so that the catalyst has stronger strength and strength stability. According to the catalyst, Mo is used as an active component, and the active component is well dispersed on the surface of the carrier and is not easy to run off by selecting a proper active component adding mode, so that the structure and activity stability of the catalyst are good. On the catalyst of the invention, two reactions of methanation and CO transformation can be carried out simultaneously, the selectivity of the methanation reaction is not lower than 90%, the catalyst can be activated when the temperature is lower than 300 ℃, and the service life is longer.

Description

Sulfur-tolerant shift methanation bifunctional catalyst and preparation method thereof

Technical Field

The invention belongs to the field of sulfur tolerant shift and methanation reactions, and particularly relates to a sulfur tolerant shift methanation bifunctional catalyst, and a preparation method and application thereof.

Background

The utilization of the coal gasification hydrogen production device by-product small amount of low heat value fuel gas is generally set with a conversion line and a non-conversion line to respectively satisfy the hydrogen and fuel gas (CO + H) of the refinery₂) But the investment of the device is large, the heat value of the fuel gas is low, and the requirements of hydrogen and the fuel gas cannot be flexibly switched. If through embedding methanation process in the transform workshop section, cancel non-transform line to shift and methanation reaction simultaneously, after purifier desorption acid gas, separate out pure hydrogen by PSA, the by-product desorption gas sends into the pipe network as high calorific value fuel gas, then can satisfy the demand to hydrogen and fuel gas simultaneously, improves the reliability, flexibility and the economic nature of device by a wide margin. The current technology mainly focuses on sulfur tolerant methanation reactions,the research on the methanation reaction of the synthesis gas mainly comprises two process routes: one is Ni/Al which is extremely sensitive to hydrogen sulfide₂O₃A system-catalyzed non-sulfur tolerant methanation process; another process route is the sulfur tolerant methanation process catalyzed by molybdenum based catalysts. The sulfur-tolerant methanation has certain cost advantage because the fine desulfurization treatment of the raw material gas is not needed, and the process can be simplified. However, relatively little research has been conducted on both sulfur tolerant shift and methanation reactions.

The catalytic cracking (FCC) catalyst in an oil refinery is the catalyst with the largest application amount in the oil refinery process, the annual amount of the catalyst used in China exceeds 100kt, and the amount of the waste agent generated after the catalyst is used is gradually increased along with the increase of the scale of the FCC, so that the catalyst is not only an economic problem, but also is more mainly an environmental protection problem. This type of waste agent has low activity and also contains a certain amount of heavy metals or nonvolatile carbon-like substances, mainly Ni, V, Fe, Cu, etc., and how to treat it has been one of the issues of concern to the skilled person.

The waste catalytic cracking catalyst mainly comprises Al₂O₃、SiO₂Clay and BaCO₃Prepared by mixing Al as a carrier₂O₃And SiO₂The content can reach about 95 percent (w), because the oxides can be used as the basic raw materials of the catalyst, in addition, most heavy metals such as Ni, V, Fe and Cu contained in the waste agent have activity to certain reactions or can increase the reaction activity, and meanwhile, the catalyst prepared by taking the waste catalytic cracking catalyst as the raw material can not only reduce the preparation cost, but also find an effective utilization way for the waste catalytic cracking catalyst with wide sources and low cost, and relieve the huge pressure of the treatment of the waste catalytic cracking catalyst to the ecological environment. At present, the method which has a more successful result is to recycle the waste agent part and reduce the amount of discarded treatment, and the method mainly comprises the steps of recycling by a magnetic separation technology, using the waste agent as a cement substitute material, using the waste agent as a flame retardant and a microorganism growth inhibitor, recrystallizing the waste agent into a catalyst and the like, but related research and reports applied to the field of molybdenum-series sulfur-tolerant shift methanation dual-function catalysts are not found.

Chinese patent application CN106140296A discloses a method for recycling catalytic cracking waste catalyst, wherein the catalytic cracking waste catalyst is used as a main aluminum source and a part of silicon source, and a fresh catalytic cracking catalyst is prepared by in-situ crystallization. However, the document does not mention how to further adjust the composition of the catalytic cracking spent catalyst on the basis of the catalytic cracking spent catalyst so as to be suitable as a carrier of the sulfur-tolerant shift methanation dual-function catalyst.

Chinese patent application CN108097264A discloses a method for preparing a catalytic cracking combustion improver, which selects waste agent (namely FCC waste catalyst) residue with platinum content of 0.06-0.1% as raw material, uses a pulverizer to pulverize the waste agent to a particle size of less than 30 μm, uses inorganic acid solution with pH value of 3-4 to mix and stir, stirs 10-12 hours at normal temperature, adds organic acid into the mixture, stirs 1-2 hours, stands for 6-8 hours, dries 2-5 hours at 110 ℃, and bakes 1-3 hours at 750 ℃ to obtain the catalyst, the inorganic acid solution: organic acid solution: the weight ratio of the waste agent residue with the platinum content of 0.06-0.1% is (5-8): 2-4): 1; then the calcined catalyst is used as a carrier. However, the spent FCC catalyst in this document must be subjected to an acid treatment, i.e. calcination, before it can be used as a support for a combustion improver, and there is no mention of how to further adjust the composition of the spent FCC catalyst on the basis of the spent FCC catalyst to make it suitable as a support for a sulfur-tolerant shift methanation dual-function catalyst.

Disclosure of Invention

In order to solve the problems, the application tries to develop a sulfur-resistant conversion methanation dual-function catalyst by taking catalytic cracking (FCC) catalyst waste agent as a carrier part material, adding a proper amount of alumina and titanium oxide materials and adding a molybdenum salt active component and a preparation method thereof₂-SiO₂-Al₂O₃The catalyst is the main part of the carrier, is prepared by adopting a kneading process, and has simple and feasible process and good stability of catalyst structure and activity. On the catalyst, two reactions of methanation and CO transformation can be carried out simultaneously, the selectivity of the methanation reaction is high, and the methanation reaction can be activated when the temperature is less than 300 ℃. The catalyst provides possibility for coal gasification hydrogen production device by-product low-heat value fuel, and is coalThe hydrogen production co-production fuel gas creates a new route, and the reliability, flexibility and economy of the coal gasification hydrogen production device are greatly improved.

Therefore, the technical problem to be solved by the invention is as follows: a sulfur-tolerant shift methanation dual-function catalyst and a preparation method thereof are provided, two reactions of methanation and CO shift can be simultaneously carried out on the catalyst, the selectivity of the methanation reaction is high, the catalyst can be activated when the temperature is lower than 300 ℃, and the service life is long. And how to use the waste catalytic cracking catalyst, such as FCC spent catalyst, as the component of the catalyst carrier, partially replace the current catalyst carrier material, thereby achieving the purpose of reducing the production cost of the catalyst, finding a more effective treatment and utilization approach for the waste catalytic cracking catalyst with wide sources and low cost, relieving the huge pressure of the waste catalytic cracking catalyst on the ecological environment, and leading the production process of the catalyst to have good economic benefit and environmental protection benefit.

In order to solve the technical problems, the invention provides a sulfur-tolerant shift methanation dual-function catalyst and a preparation method thereof, wherein a carrier of the sulfur-tolerant shift methanation dual-function catalyst is a composite oxide formed by oxides of Al, Si, Ti and Ba, Mo is used as an active component, and the content of Mo is 13.0-30.0 wt%, preferably 16.5-25.0 wt% calculated by molybdenum oxide.

The preparation process of the catalyst of the invention is as follows:

raw material treatment:

a certain amount of waste catalytic cracking catalyst is firstly roasted at high temperature, crushed and sieved;

silica (SiO) in spent catalytic cracking catalyst₂) And alumina (Al)₂O₃) The total content should not be less than 85 wt.%, based on the weight of the spent catalytic cracking catalyst; the dosage of the waste catalytic cracking catalyst accounts for 20-50 wt% of the weight of the catalyst; the crushed waste catalytic cracking catalyst is sieved by a 200-mesh sieve.

The roasting temperature for treating the waste catalytic cracking catalyst is 550-800 ℃, preferably 650 ℃, and the roasting time is 2-10 hours, preferably 4-6 hours.

The particle size of the treated waste catalytic cracking catalyst is 200 meshes, preferably 220 meshes.

Preparing an active component solution:

dissolving a certain amount of soluble molybdenum salt with deionized water to obtain a solution A; preferably, the molybdenum salt is dissolved in water by heating, and a proper amount of ethylenediamine is added to obtain a stable molybdenum salt aqueous solution; ethylenediamine is preferably added dropwise in an amount of 1-3(ml ethylenediamine): 10-40(g molybdenum salt); the molybdenum salt is preferably ammonium heptamolybdate.

The catalyst forming and active component loading process comprises the following steps:

uniformly mixing the weighed waste catalytic cracking catalyst with a certain amount of powdery solid compound containing aluminum and powdery solid compound containing titanium, a pore-expanding agent and a binder, adding the solution A, uniformly kneading, and forming, drying and roasting to obtain a catalyst finished product.

The aluminum-containing powdery solid compound is selected from pseudo-boehmite, alumina gel, aluminum nitrate and aluminum acetate, and is preferably pseudo-boehmite; the content is 5-15 wt.% (m/m) calculated by alumina.

The titanium-containing powdery solid compound is selected from metatitanic acid and titanium oxide, and preferably metatitanic acid in terms of titanium oxide; the content is 15-40 wt.% (m/m).

The pore-expanding agent is selected from sesbania powder, citric acid, starch and sucrose, and is preferably sesbania powder; the content thereof is 2 to 5 wt.% (m/m), preferably 3 to 4 wt.% (m/m).

The binder is selected from acetic acid, citric acid, oxalic acid and nitric acid, preferably nitric acid; the content thereof is 1 to 6 wt.% (m/m), preferably 2 to 4 wt.% (m/m).

The roasting temperature for forming the catalyst is 500-650 ℃, and preferably 560 ℃.

The pore volume of the catalyst is preferably greater than 0.2cm³In g, more preferably greater than 0.3cm³(ii) in terms of/g. The specific surface area is preferably greater than 80m²A/g, more preferably more than 100m²/g。

The active component in the catalyst is molybdenum, wherein the content of molybdenum is 13.0-30.0 wt.% (m/m), preferably 16.5-25.0 wt.% (m/m) calculated by molybdenum oxide.

The catalyst has a CO content of 20% (v/v), CO, in the inlet gas₂25% (v/v), 0.2% sulfur, and the balance H₂At the time of the reaction, the inlet pressure is 3.5MPa, and the dry gas space velocity is 2000h^-1And under the condition of water-gas ratio of 0.1, the CO outlet of the methanation outlet of the sulfur-tolerant part is less than 12 percent, and the CH is₄The content is more than 4.0 percent. The inlet gas may be derived from a process for producing syngas from heavy feedstocks such as residuum, heavy oil, petroleum coke, coal, and the like.

The sulfur-tolerant shift methanation bifunctional catalyst has the following advantages:

1. the catalyst of the invention has higher strength, good stability of structure and activity, low loss rate of active components and longer service life. The Al, Si and Ba oxides in the carrier are mainly from the waste catalytic cracking catalyst, the waste catalytic cracking catalyst can partially replace the common alumina or aluminum-containing compound in the bifunctional catalyst after being treated, and meanwhile, a titanium-containing compound is added by adopting a proper method, so that the catalyst has stronger strength and strength stability. According to the catalyst, Mo is used as an active component, and the active component is well dispersed on the surface of the carrier and is not easy to run off by selecting a proper active component adding mode, so that the structure and activity stability of the catalyst are good.

2. On the catalyst of the invention, two reactions of methanation and CO transformation can be carried out simultaneously, the selectivity of the methanation reaction is not lower than 90%, the catalyst can be activated when the temperature is lower than 300 ℃, and the service life is longer.

3. The preparation method of the catalyst is simple, and meanwhile, the catalyst raw material adopts the waste catalytic cracking catalyst with low cost, so that the preparation cost of the catalyst is greatly reduced, a more effective way is found for the comprehensive utilization of the waste catalytic cracking catalyst, and the catalyst has good economic benefit and environmental protection benefit.

Drawings

In order that the present disclosure may be more readily and clearly understood, the following detailed description of the present disclosure is provided in connection with specific embodiments thereof and the accompanying drawings, in which,

the device used by the invention is used for simulating industrial conditions, measuring the concentration change conditions of the 'original particle size' catalyst under different conditions, investigating the performances of the catalyst such as conversion activity, stability and the like, and comprehensively evaluating various performances of the catalyst. The process comprises the steps of adding a certain amount of water according to the requirements of different water-gas ratios, gasifying the water at high temperature, feeding the water and the feed gas into a reaction tube together for water gas shift and methanation reaction, and analyzing tail gas after the reaction by using a chromatographic method, wherein FIG. 1 is a schematic flow diagram of a pressurization evaluation device.

The reference numbers in the figures denote: 1. a raw material purifier; 2. a pressure reducer; 3. a mixer; 4. a pressure gauge; 5. a shutdown valve; 6. heating furnace; 7. a reaction tube; 8. a thermocouple tube inside the tube; 9. a condenser; 10. a separator; 11. a liquid discharge device; 12. a wet flow meter; 13. a vaporizer; 14. a water tank; 15. a water metering pump.

Detailed Description

Example 1

The waste catalytic cracking catalyst is roasted for 5 hours at the temperature of 650 ℃, and then is crushed and sieved by a 220-mesh sieve.

Dissolving 24.5g of ammonium heptamolybdate with 40.0ml of deionized water, and adding 1ml of ethylenediamine to obtain a stable molybdenum salt aqueous solution A; 3.0g of citric acid and 1.0g of oxalic acid in deionized water were dissolved to obtain solution B.

Weighing 45.0g of the treated waste catalytic cracking catalyst, 7.2g of pseudo-boehmite, 40.0g of metatitanic acid, 3.0g of sesbania powder and 1g of starch, uniformly mixing, adding the solution A, uniformly kneading, adding the solution B, uniformly kneading to form a phi 3 strip, naturally drying, roasting at 560 ℃ for 3 hours, and naturally cooling to room temperature. Thus obtaining the finished product catalyst C-1. The strength and activity results are shown in Table 1.

Example 2

The waste catalytic cracking catalyst is roasted for 2 hours at the temperature of 800 ℃, and then is crushed and sieved by a 200-mesh sieve.

30.7g of ammonium heptamolybdate was dissolved in 45.0ml of deionized water, and 1ml of ethylenediamine was added to obtain a stable aqueous solution a of molybdenum salt; weighing 30.0g of the treated waste catalytic cracking catalyst, 20.0g of alumina gel, 35.0g of titanium oxide, 2.0g of starch and 2.0g of cane sugar, uniformly mixing, adding the solution A, kneading, forming into phi 3 strips, naturally drying, roasting at 530 ℃ for 4 hours, and naturally cooling to room temperature. Thus obtaining the finished product catalyst C-2. The strength and activity results are shown in Table 1.

Example 3

The waste catalytic cracking catalyst is roasted for 10 hours at the temperature of 550 ℃, and then crushed and sieved by a 230-mesh sieve.

Dissolving 16.0g of ammonium heptamolybdate with 40.0ml of deionized water, and adding 1ml of ethylenediamine to obtain a stable molybdenum salt aqueous solution A; weighing 50.0g of the treated waste catalytic cracking catalyst, 204.0g of aluminum nitrate nonahydrate, 22.0g of titanium oxide, 4.0g of sesbania powder and 2g of starch, uniformly mixing, adding the solution A, uniformly kneading to form a phi 3 strip, naturally drying, roasting at 600 ℃ for 2 hours, and naturally cooling to room temperature. Thus obtaining the finished product catalyst C-3. The strength and activity results are shown in Table 1.

Example 4

The waste catalytic cracking catalyst is roasted for 3 hours at the temperature of 700 ℃, and then is crushed and sieved by a 250-mesh sieve.

Dissolving 36.8g of ammonium heptamolybdate with 60.0ml of deionized water, and adding 1ml of ethylenediamine to obtain a stable molybdenum salt aqueous solution A; weighing 20.0g of the treated waste catalytic cracking catalyst, 75.0g of aluminum acetate, 53.0g of metatitanic acid, 2g of oxalic acid, 2.0g of sucrose and 3.0g of sesbania powder, uniformly mixing, adding the solution A, uniformly kneading to form a phi 3 strip, naturally airing, roasting at 650 ℃ for 2 hours, and naturally cooling to room temperature. Thus obtaining the finished product catalyst C-4. The strength and activity results are shown in Table 1.

Example 5

The waste catalytic cracking catalyst is roasted for 8 hours at the temperature of 550 ℃, and then crushed and sieved by a 220-mesh sieve.

Firstly, 27g of ammonium heptamolybdate is dissolved by 45.0ml of deionized water, and 1ml of ethylenediamine is added to obtain a stable molybdenum salt aqueous solution A;

weighing 40.0g of the treated waste catalytic cracking catalyst, 13.6g of aluminum nitrate, 30.0g of titanium oxide, 5.0g of sesbania powder and 3g of cane sugar, uniformly mixing, adding the solution A, adding 5.0ml of dilute nitric acid, uniformly kneading to form a phi 3 strip, naturally airing, roasting at 500 ℃ for 5 hours, and naturally cooling to room temperature. Thus obtaining the finished product catalyst C-5. The strength and activity results are shown in Table 1.

Example 6

The waste catalytic cracking catalyst is roasted for 6 hours at the temperature of 600 ℃, and then crushed and sieved by a 240-mesh sieve.

Firstly, 36.8g of ammonium heptamolybdate is dissolved by 60.0ml of deionized water, and 1ml of ethylenediamine is added to obtain a stable molybdenum salt aqueous solution A; weighing 42.0g of the treated waste catalytic cracking catalyst, 18.6g of pseudo-boehmite, 20.0g of metatitanic acid, 4.0g of sesbania powder and 2g of citric acid, uniformly mixing, adding the solution A, uniformly kneading, adding 3.0ml of acetic acid, kneading to form a phi 3 strip, naturally drying, roasting at 550 ℃ for 3 hours, and naturally cooling to room temperature. Thus obtaining the finished product of the catalyst C-6. The strength and activity results are shown in Table 1.

Comparative example 1

Mixing silicon dioxide (SiO)₂) And alumina (Al)₂O₃) The spent catalytic cracking catalyst with a total content of 80% was prepared according to the protocol of example 1 to obtain the finished product, catalyst D-1. The strength and activity results are shown in Table 2.

Comparative example 2

The waste catalytic cracking catalyst is roasted for 10 hours at the temperature of 500 ℃, and then is crushed and sieved by a 180-mesh sieve.

Firstly, dissolving 18.4g of ammonium heptamolybdate by 50.0ml of deionized water, and adding 1ml of ethylenediamine to obtain a stable molybdenum salt aqueous solution A; weighing 60.0g of the treated waste catalytic cracking catalyst, 7.1g of pseudo-boehmite, 26.7g of metatitanic acid, 2.0g of sesbania powder and 2.0g of citric acid, uniformly mixing, adding the solution A, uniformly kneading, adding 3.0ml of acetic acid and 3.0g of citric acid, kneading to form a phi 3 strip, naturally airing, roasting at 650 ℃ for 3 hours, and naturally cooling to room temperature. Thus obtaining the finished product of the catalyst D-2. The strength and activity results are shown in Table 2.

Comparative example 3

The waste catalytic cracking catalyst is roasted for 8 hours at the temperature of 700 ℃, and then is crushed and sieved by a 220-mesh sieve.

Firstly, dissolving 12.3g of ammonium molybdate by using 40.0ml of deionized water, and adding 1ml of ethylenediamine to obtain a stable molybdenum salt aqueous solution A; weighing 70.0g of the treated waste catalytic cracking catalyst, 68.0g of aluminum nitrate nonahydrate, 15.0g of titanium oxide and 4.0g of sesbania powder, uniformly mixing, adding the solution A, kneading uniformly to form a phi 3 strip, naturally drying, roasting at 600 ℃ for 3 hours, and naturally cooling to room temperature. Thus obtaining the finished product of the catalyst D-3. The strength and activity results are shown in Table 2.

Comparative example 4

Firstly, 36.8g of ammonium heptamolybdate is dissolved by 60.0ml of deionized water, and 1ml of ethylenediamine is added to obtain a stable molybdenum salt aqueous solution A; weighing 52.0g of the treated waste catalytic cracking catalyst, 24.3g of pseudo-boehmite, 4.0g of sesbania powder and 2g of citric acid, uniformly mixing, adding the solution A, uniformly kneading, adding 3.0ml of acetic acid, kneading into a phi 3 strip shape, naturally drying, roasting at 550 ℃ for 3 hours, and naturally cooling to room temperature. Thus obtaining the finished product of the catalyst D-4. The strength and activity results are shown in Table 2.

The sulfur-tolerant shift activity and methanation selectivity of the catalysts of the examples of the present invention and the comparative examples were measured by using a pressure evaluation apparatus, and the results are shown in tables 1 and 2.

Wherein the raw material gas composition is as follows: content of CO: 20.0 percent; CO 2₂The content is as follows: 25.0 percent;

H₂and (2) S content: more than 0.2 percent; and the balance: h₂；

Catalyst loading: 60 mL;

vulcanization conditions are as follows:

temperature: 250 ℃; pressure: 2.0 MPa; dry gas space velocity: 2000h^-1；H₂And (2) S content: 0.3 percent;

time: 20 h;

initial evaluation conditions for catalyst pressurization:

inlet temperature: 300 ℃; pressure: 3.5 MPa; water/gas: 0.1;

dry gas space velocity: 2000h^-1；H₂And (2) S content: 0.2 percent; time: and (4) 40 h.

TABLE 1 strength and pressure activity of catalysts of the present application

TABLE 2 strength and pressure activity of the comparative example catalysts

As can be seen from the evaluation results in tables 1 and 2, the catalyst of the present application has a significantly better combination of sulfur tolerance shift activity and methanation selectivity than the comparative example.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A preparation method of a sulfur-tolerant shift methanation bifunctional catalyst is characterized by comprising the following steps:

(1) raw material treatment:

silicon dioxide (SiO) in the spent catalytic cracking catalyst₂) And alumina (Al)₂O₃) The total content is not lower than 85 wt.%, and the dosage of the waste catalytic cracking catalyst accounts for 20-50 wt.% of the weight of the catalyst; sieving the crushed waste catalytic cracking catalyst with a 200-mesh sieve;

(2) preparing an active component solution:

dissolving a certain amount of soluble molybdenum salt by using deionized water, and adding a proper amount of ethylenediamine to obtain a stable molybdenum salt aqueous solution A;

(3) the catalyst forming and active component loading process comprises the following steps:

uniformly mixing the weighed waste catalytic cracking catalyst powder with a certain amount of aluminum-containing powdery solid compound, titanium-containing powdery solid compound, pore-enlarging agent and binder, adding the solution A, uniformly kneading, and forming, drying and roasting to obtain a catalyst finished product.

2. The preparation method of the sulfur-tolerant shift methanation dual-function catalyst according to claim 1, characterized in that in the step (1), the roasting temperature for treating the waste catalytic cracking catalyst is 550-800 ℃, preferably 650 ℃, and the roasting time is 2-10h, preferably 4-6 h.

3. The preparation method of the sulfur-tolerant shift methanation dual-function catalyst according to claim 1, characterized in that in the step (1), the crushed waste catalytic cracking catalyst is sieved by a 220-mesh sieve.

4. The preparation method of the sulfur-tolerant shift methanation dual-function catalyst according to claim 1, wherein in the step (2), molybdenum salt is preferably heated in water to be dissolved so as to obtain molybdenum salt water solution, and the molybdenum salt is preferably ammonium heptamolybdate.

5. The preparation method of the sulfur-tolerant shift methanation dual-function catalyst according to claim 1, wherein in the step (3), the aluminum-containing powdery solid compound is selected from pseudo-boehmite, alumina gel, aluminum nitrate, and aluminum acetate, preferably pseudo-boehmite; the content is 5-15 wt.% (m/m) calculated by alumina.

6. The preparation method of the sulfur-tolerant shift methanation dual-function catalyst according to claim 1, characterized in that, in the step (3), the titanium-containing powdery solid compound is selected from metatitanic acid and titanium oxide, and is preferably metatitanic acid; the content is 15-40 wt.% (m/m).

7. The preparation method of the sulfur-tolerant shift methanation bifunctional catalyst as claimed in claim 1, wherein in the step (3), the pore-expanding agent is selected from sesbania powder, citric acid, starch, sucrose, preferably sesbania powder; its content is 2-5 wt.% (m/m), preferably 3-4 wt.% (m/m); the binder is selected from acetic acid, citric acid, oxalic acid and nitric acid, preferably nitric acid; the content thereof is 1 to 6 wt.% (m/m), preferably 2 to 4 wt.% (m/m).

8. A sulfur shift tolerant methanation dual function catalyst prepared according to any one of claims 1 to 7, wherein the catalyst comprises molybdenum as an active ingredient in an amount of 13.0 to 30.0 wt.%, preferably 16.5 to 25.0 wt.%, based on molybdenum oxide.

9. The sulfur-tolerant shift methanation dual-function catalyst according to claim 8, wherein the carrier is a composite oxide composed of oxides of Al, Si, Ti and Ba.

10. Use of a sulfur tolerant shift methanation dual function catalyst according to any one of claims 8 to 9 for simultaneously catalysing both methanation and sulfur tolerant shift reactions.