Sulfided shift catalyst protectant and catalyst protection method

Abstract

The application discloses a sulfidation type shift catalyst protective agent and a catalyst protection method, and belongs to the technical field of sulfur-tolerant shift catalysts. Sulfidation state shift catalysts need to be passivated or pretreated in other ways to facilitate catalyst storage and transportation, but the existing methods may have the phenomena of affecting catalyst activity, complex application starting process or equipment blockage. The application comprises 92-99wt% of a solvent and 1-8wt% of a protective component; wherein the solvent comprises 95-99.5wt% of an ethanol solution and 0.5-5.0wt% of diethyl ether, the ethanol solution is an ethanol solution with an ethanol mass content of 95% or more; and the protective component comprises a mixture of one or more of n-heptane, ammonium sulfide and glyceride in any proportion. The obtained sulfidation state catalyst can be stably stored, transported and filled in air without heating, significantly reduces the catalyst starting time and is convenient to use.

Description

TECHNICAL FIELD

[0001] The application relates to a sulfidation type shift catalyst protective agent and a catalyst protection method. BACKGROUND

[0002] The CO sulfur-tolerant shift technology and catalyst are widely applied in hydrogen production, ammonia synthesis, methanol synthesis, gasoline synthesis and city gas production. The sulfur-tolerant shift catalyst used in the CO sulfur-tolerant shift technology must be sulfidized to change the cobalt-molybdenum active component from an oxidation state into a sulfidation state, so that the catalyst has the shift activity. The sulfidation effect of the catalyst directly influences the use performance of the catalyst. The sulfidation process is divided into in-vessel online sulfidation and ex-vessel presulfidation. The ex-vessel presulfidation technology can improve the utilization rate of a sulfidation agent, reduce environmental pollution, save sulfidation energy consumption, reduce the starting cost and shorten the starting period, and finally increase the economic benefits of enterprises, and is gradually favored by enterprises. However, the sulfidation state sulfur-tolerant shift catalyst has oxygen affinity, and when it is exposed to an oxygen-containing environment, the catalyst will have an exothermic reaction with oxygen, and the temperature will rise until combustion. The self-heating combustion property not only may influence the activity of the catalyst, but also easily causes environmental pollution. Therefore, the sulfidation state shift catalyst needs to be passivated or pretreated, so as to facilitate the storage and transportation of the catalyst.

[0003] At present, the technology can be divided into three types of gas phase passivation, liquid phase passivation and solid phase passivation. The gas phase passivation mainly uses O2 to oxidize the surface of the sulfidation state catalyst particles at a certain temperature to form a dense oxide film, so as to isolate O2 in the air and achieve the protection purpose. However, the thermal oxygen reaction easily influences the performance of the catalyst and also consumes the catalytic activity of the catalyst itself. The liquid passivation mainly uses organic hydrocarbons to form a protective layer on the surface of the catalyst by means of impregnation, spraying and blending. This passivation can be considered as a simple physical protection process. The protective layer can be removed by heating, hydrogenolysis or solvent dissolution when used. However, the organic hydrocarbons easily solidify at low temperature of a pipeline, causing pipeline blockage. The solid passivation uses the temperature difference between the passivation substance and the catalyst to form a protective film on the surface of the catalyst, so as to isolate air. The protective film formed by the method is not uniform, and the passivation effect is poor. SUMMARY

[0004] The technical problem to be solved by the application is to overcome the shortcomings of the prior art and provide a protective layer which does not react with the catalyst, is uniform, does not need to be removed by starting sulfidation and has good protection effect.

[0005] The technical scheme adopted by the present application to solve its technical problems is: a sulfided shift catalyst protective agent, characterized in that: 92-99wt% of a solvent and 1-8wt% of a protective component; wherein the solvent comprises 95-99.5wt% of an ethanol solution and 0.5-5.0wt% of diethyl ether, the ethanol solution is an ethanol solution with an ethanol mass content of 95% or more; and the protective component comprises one or more of n-heptane, ammonium sulfide, and glyceride in any proportion.

[0006] The protective agent is applied to the surface of the catalyst, and the protective component is coated on the surface of the sulfided shift catalyst under the carrying of the solvent, and after the solvent is volatilized, the organic compounds of the protective component remain in the form of liquid or solid in the inner pores and surface of the catalyst, thereby protecting the sulfides of the active centers. The boiling point of the protective component is about 60-240 DEG C, the lower limit of the boiling point ensures the cooperation effect with the solvent, ensures that the solvent is preferentially volatilized and the protective component is left, and the cooperation effect is formed with the specific solvent composition, thereby playing a role in stabilizing and protecting the active centers of the catalyst, and the upper limit of 240 DEG C means that the catalyst can be used according to the conventional start-up conditions when needed, and the protective component can be volatilized at the start-up temperature, and the catalyst is activated, and the several protective components do not have any influence on the process and product even if they enter the subsequent links, and do not adhere to and block the pipeline. The obtained sulfided catalyst can be stably stored, transported and loaded in air without heating, significantly reduces the start-up time of the catalyst and is convenient to use.

[0007] In addition, the diethyl ether in the solvent has a special synergistic effect with the several protective components, can play a good intermolecular organic lubrication and dispersion effect, is beneficial to the protective component to form a uniform and dense protective film on the surface of the catalyst, and the ethanol can effectively bind the diethyl ether, avoid the diethyl ether from being volatilized too fast and losing the dispersion effect on the protective component, and simultaneously carry the diethyl ether and the protective component to diffuse to a wider area, thereby improving the protection uniformity.

[0008] Preferably, the content of the protective component is 3-5% by weight of the sulfided shift catalyst protective agent.

[0009] The preferred protective component content is beneficial to the diffusion and film formation effect of the protective component, and can reduce the cost.

[0010] Preferably, the weight content of the diethyl ether in the solvent is 2-3%.

[0011] The method for protecting the sulfidation shift catalyst, characterized in that: the sulfidation shift catalyst is uniformly sprayed with the protective agent for sulfidation shift catalyst according to any one of claims 1-3, and then dried by blowing with carbon dioxide or inert gas containing 10-30% air by volume; the surface temperature of the catalyst is less than or equal to 50°C during the blowing.

[0012] The method for protecting the sulfidation shift catalyst, characterized in that: the sulfidation shift catalyst is uniformly sprayed with the protective agent for sulfidation shift catalyst according to any one of claims 1-3, and then dried by blowing with carbon dioxide or inert gas containing 10-30% air by volume; the surface temperature of the catalyst is less than or equal to 50°C during the blowing.

[0013] Further preferably, the gas is carbon dioxide.

[0014] As a filler, it has good inert ability, does not react with other components and has very low cost.

[0015] Preferably, the surface temperature of the catalyst during the blowing is less than or equal to 40°C.

[0016] It can further avoid the volatilization of the protective component and reduce the possibility of reaction between air and the catalyst, thereby protecting the performance of the catalyst.

[0017] Preferably, the blowing and drying are performed at a blowing space velocity of 100-200 h -1 .

[0018] Preferably, the blowing and drying are performed until the surface temperature of the sulfidation shift catalyst is less than or equal to the temperature of the blowing gas.

[0019] The film forming process on the surface of the catalyst will release a certain amount of heat, and when the surface temperature of the catalyst is less than or equal to the temperature of the blowing gas, it means that the film forming process has been completed, thereby ensuring the film forming effect while saving time and energy.

[0020] Preferably, the sulfidation shift catalyst is a fully sulfided sulfur-tolerant shift catalyst.

[0021] Compared with the prior art, the present application has the beneficial effect that the protective agent is applied to the surface of the catalyst, the protective component is coated on the surface of the fully vulcanized conversion catalyst under the carrying of the solvent, and the organic compound of the protective component remains in the form of liquid or solid in the inner hole and surface of the catalyst after the solvent is volatilized, thereby playing a role in protecting the active center sulfide. The boiling point of the protective component is about 60-240°C, the lower limit of the boiling point ensures the matching effect with the solvent, ensures that the solvent is preferentially volatilized and the protective component is left, plays a role in stably protecting the active center sulfide of the catalyst, forms a matching effect with the specific solvent component, and the upper limit of 240°C means that the catalyst can be started under conventional starting conditions, the protective component is volatilized at the starting temperature, and the catalyst is activated, and the several protective components do not have any impact on the process and product even if they enter the subsequent link, and do not adhere to and block the pipeline. The obtained vulcanized catalyst can be stably stored, transported and loaded in air without heating, significantly reduces the starting time of the catalyst and is convenient to use. DETAILED DESCRIPTION

[0022] The present application is further described below in combination with examples, and examples 1, 5 and 6 are the best examples of the present application.

[0023] The QCS-01, QCS-03 and QCS-04 catalysts used in the following examples and comparative examples are fully vulcanized pre-sulfurized sulfurization catalysts produced by Qilu Kelico Company.

[0024] Example 1

[0025] A vulcanized conversion catalyst protective agent and a catalyst protection method, the solvent is an ethanol solution containing 2.5% by weight of diethyl ether, the ethanol solution is anhydrous ethanol; the protective component is 0.5% by weight of n-heptane and 4.0% by weight of ammonium sulfide based on the solvent, a vulcanized conversion catalyst protective agent is obtained after complete dissolution, 100g of fully vulcanized catalyst QCS-01 is placed in a sealed container, QCS-01 is an industrial sample produced by Qilu Kelico Company, is purged with CO2 at a pressure of 1.0MPa until there is no sulfur-containing impurity in the outlet gas, the organic mixed solution is uniformly sprayed on the catalyst until adsorption saturation and surface wetting, and the catalyst is purged with a CO2 mixed gas containing 20% by volume of air at a space velocity of 200h-1, the temperature of the catalyst during purging does not exceed 40°C, and the catalyst is taken out and placed in air for weighing when the surface of the catalyst is dry and does not generate heat. -1 The space velocity is 200h-1, the temperature of the catalyst during purging does not exceed 40°C, and the catalyst is taken out and placed in air for weighing when the surface of the catalyst is dry and does not generate heat.

[0026] Example 2

[0027] A sulfidation type shift catalyst protective agent and a catalyst protection method, the solvent is an ethanol solution containing 3.0% by weight of diethyl ether, the ethanol is a 95.5% by weight ethanol aqueous solution; the protective component is 0.5% by weight of ammonium sulfide and 5.0% by weight of glyceride of the solvent, after complete dissolution, a sulfidation type shift catalyst protective agent is obtained, 100g of completely sulfidized pre-sulfidation catalyst QCS-01 is taken, QCS-01 is an industrial sample produced by Qilu Keli Company, the sulfidation type shift catalyst protective agent is uniformly sprayed on the catalyst until adsorption saturation and surface wetting, a CO2 mixed gas containing 30% by volume of air is used to sweep at 150h -1 The space velocity of the sweeping is 150h-1, the catalyst temperature does not exceed 45℃ during the sweeping, when the catalyst surface is dry and does not generate heat, the catalyst is taken out and placed in air for weighing.

[0028] Example 3

[0029] A sulfidation type shift catalyst protective agent and a catalyst protection method, the solvent is an anhydrous ethanol solution containing 5% by weight of diethyl ether; the protective component is 1% by weight of glyceride of the solvent, after complete dissolution, a sulfidation type shift catalyst protective agent is obtained, 100g of completely sulfidized catalyst QCS-01 is taken into a sealed container, QCS-01 is an industrial sample produced by Qilu Keli Company, CO2 is used to sweep at a pressure of 1.0MPa, the sweeping is performed until there is no sulfur-containing impurity in the outlet gas, the organic mixed solution is uniformly sprayed on the catalyst until adsorption saturation and surface wetting, a CO2 mixed gas containing 10% by volume of air is used to sweep at 100h -1 The space velocity of the sweeping is 100h-1, the catalyst temperature does not exceed 50℃ during the sweeping, when the catalyst surface is dry and does not generate heat, the catalyst is taken out and placed in air for weighing.

[0030] Example 4

[0031] A sulfidation type shift catalyst protective agent and a catalyst protection method, on the basis of example 1, the volume content of air in the sweeping gas is set to 35%, and other conditions are the same as in example 1.

[0032] Example 5

[0033] A sulfidation type shift catalyst protective agent and a catalyst protection method, the solvent is an ethanol solution containing 0.5% by weight of diethyl ether, the ethanol solution is a 95.5% ethanol aqueous solution; the protective component is 0.5% by weight of ammonium sulfide, 2.5% by weight of n-heptane and 5.0% by weight of glyceride of the solvent, and the sulfidation type shift catalyst protective agent is obtained after complete dissolution; 100g of completely sulfidized catalyst QCS-03 is placed in a sealed container, QCS-03 is an industrial sample produced by Qilu Kelai Company, and CO2 is used for blowing at a pressure of 1.0MPa until there is no sulfur-containing impurity in the outlet gas; the organic mixed solution is uniformly sprayed on the catalyst until adsorption saturation and surface wetting, and the catalyst is blown with 20% by volume of air in nitrogen at a space velocity of 200h-1, 40℃, and 1.0MPa. -1 When the catalyst surface is dry and does not generate heat, it is taken out and placed in air for weighing.

[0034] Example 6

[0035] A sulfidation type shift catalyst protective agent and a catalyst protection method, the solvent is an ethanol solution containing 0.5% by weight of diethyl ether, the ethanol solution is a 95.5% ethanol aqueous solution; the protective component is 0.5% by weight of ammonium sulfide, 2.5% by weight of n-heptane and 5.0% by weight of glyceride of the solvent, and the sulfidation type shift catalyst protective agent is obtained after complete dissolution; 100g of completely sulfidized catalyst QCS-03 is placed in a sealed container, QCS-03 is an industrial sample produced by Qilu Kelai Company, and CO2 is used for blowing at a pressure of 1.0MPa until there is no sulfur-containing impurity in the outlet gas; the organic mixed solution is uniformly sprayed on the catalyst until adsorption saturation and surface wetting, and the catalyst is blown with 20% by volume of air in nitrogen at a space velocity of 200h-1, 40℃, and 1.0MPa. -1 When the catalyst surface is dry and does not generate heat, it is taken out and placed in air for weighing.

[0036] Comparative Example 1

[0037] A sulfidation type shift catalyst protective agent and a catalyst protection method, on the basis of Example 1, the solvent is set to pure anhydrous ethanol without diethyl ether, and other conditions are the same as those in Example 1.

[0038] Comparative Example 2

[0039] A sulfidation type shift catalyst protective agent and a catalyst protection method, on the basis of Example 1, the solvent is set to an ethanol solution containing 6% diethyl ether, and anhydrous ethanol is used, and other conditions are the same as those in Example 1.

[0040] Comparative Example 3

[0041] A sulfide-type conversion catalyst protectant and catalyst protection method are provided. Based on Example 1, ammonium sulfide and n-heptane are both set to 4.5% of the solvent weight, and other conditions are the same as in Example 1.

[0042] Performance testing

[0043] The catalysts protected by the above-described embodiments and comparative examples were subjected to pressure activity tests, and compared with the same batch of oxidized catalysts that underwent in-reactor sulfidation (i.e., the active component of the catalyst is a metal oxide, while the active component of the fully sulfidated catalyst is a metal sulfide; metal oxides do not have conversion activity and must be converted into metal sulfides through sulfidation to acquire conversion activity. Oxidized catalysts QCS-01, QCS-03, and QCS-04 were passivated in the oxygen gas phase and then treated with in-reactor sulfidation to obtain fully sulfidated catalysts). Sulfidation conditions: pressure 2.0 MPa, dry gas hourly space velocity 2000 h⁻¹, H₂S concentration in the sulfidation gas 0.3% (v / v), sulfidation at 250°C for 10 h, followed by sulfidation at 300°C for 5 h, and then sulfidation at 350°C for 5 h. Oxidized catalyst sulfidation conditions: pressure 2.0 MPa, dry gas hourly space velocity 2000 h⁻¹. -1 The H2S concentration in the sulfidation gas was 0.3% (v / v). Sulfidation was carried out at 250℃ for 10 hours, then increased to 300℃ for another 5 hours, and finally increased to 350℃ for another 5 hours. After sulfidation in the reactor, catalysts QCS-01, QCS-03, and QCS-04 were not removed before being subjected to pressurized activity testing to measure the pressurized activity of the oxidized catalysts. After complete sulfidation, the catalysts inevitably come into contact with oxygen and react; if this is not addressed promptly, their activity will be significantly affected.

[0044] Overall process flow: A pressurized activity evaluation device was used to simulate industrial operating conditions and compare the catalyst's shift activity. Industrial syngas was selected as the feed gas (composition: CO content: 50.0%; H2S content: 0.2%, balance hydrogen). A certain amount of water was added according to different water-to-gas ratio requirements. After high-temperature gasification, the water was introduced into the reaction tube along with the feed gas for water-to-gas shift reaction. The tail gas after the reaction was analyzed by chromatography. The catalyst testing conditions were: inlet temperature 250℃; pressure 4.0 MPa; water / gas ratio 1.0; dry gas hourly space velocity 3000 h⁻¹. -1 The H2S content was 0.2%~0.3%; the time was 20h.

[0045] The final test results are shown in Table 1 below. The CO conversion rate reflects the activity of the catalyst, while the catalyst weight gain reflects the amount of sulfide-state conversion catalyst coated with the protective agent.

[0046] Table 1 Performance Test Results

[0047] .

[0048] The catalysts obtained from Comparative Example 3 and Comparative Example 4 all showed the phenomenon of sticking and caking.

[0049] As shown in Table 1, the CO conversion rate of the catalysts treated by the application is equivalent to that of the same batch of oxidized catalysts sulfided in the reactor, and the comprehensive effect is obviously better than that of the comparative examples. Moreover, no pipe blockage phenomenon occurs during the application of the catalyst, and the catalyst is directly used for starting without the process of activating the catalyst.

[0050] The above description is merely preferred embodiments of the present application, but not a form of limitation to the present application, and any skilled person in the art can make changes or modifications to the equivalent embodiments by using the disclosed technical contents. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solution content of the present application still belongs to the protection scope of the present application.

Claims

1. A sulfidation type shift catalyst protectant characterized by: The protective component includes one or more of n-heptane, ammonium sulfide and glyceride in any proportion.

2. The sulfidation shift catalyst protectant of claim 1, wherein: The protective component is 3-5% of the weight of the sulfided shift catalyst protective agent.

3. The sulfidation shift catalyst protectant of claim 1, wherein: The weight content of the ether in the solvent is 2-3%.

4. A method for protecting a sulfurated shift catalyst, characterized by: The sulfided shift catalyst is uniformly sprayed with the sulfided shift catalyst protective agent of any one of claims 1-3, and then dried by blowing with an inert gas containing 10-30% air by volume; the surface temperature of the catalyst during blowing is less than or equal to 50°C.

5. The method of protecting a sulfurated shift catalyst according to claim 4, characterized in that: The surface temperature of the catalyst is less than or equal to 40°C.

6. The method of protecting a sulfurated shift catalyst according to claim 4, characterized in that: The purging drying adopts a purging air speed of 100~200h -1 .

7. The method of protecting a sulfurated shift catalyst according to claim 4, characterized in that: The drying by blowing is performed until the surface temperature of the sulfided shift catalyst is less than or equal to the temperature of the blowing gas.

8. The method of protecting a sulfur-forming shift catalyst according to claim 4, characterized in that: The sulfided shift catalyst is a completely sulfided sulfur-tolerant shift catalyst.