Gas decarburization iron-nickel protective agent, its preparation method and application and method for removing decarburization iron-nickel from methanol synthesis gas

Abstract

This invention relates to the field of gaseous decarbonylation of iron and nickel, specifically to a gaseous decarbonylation protective agent, its preparation method, application, and a method for removing decarbonylation of iron and nickel from methanol synthesis gas. The protective agent comprises an active component, a support, and an auxiliary agent. The active component comprises elemental copper and elemental zinc, and the support comprises kaolin. In this system, the active component is distributed between the kaolin support and adheres to the support. The copper-zinc active system protective agent exhibits good activity and a higher decarbonylation capacity, better protecting the long-term operation of the methanol synthesis catalyst. Kaolin has a large specific surface area and numerous micropores, enabling it to fully physically adsorb carbonylation of iron and nickel, which then catalytically dissociates and deposits afterward at the copper-zinc active centers.

Description

Technical Field

[0001] This invention relates to the field of gas decarbonylation of iron and nickel, specifically to a gas decarbonylation of iron and nickel protective agent, its preparation method and application, and a method for removing decarbonylation of iron and nickel from methanol synthesis gas. Background Technology

[0002] With the rapid development of large-scale methanol production, the presence of iron carbonyl in syngas has become a major problem affecting the lifespan of methanol catalysts and the quality of crude methanol. Its side effects are also extremely significant and multifaceted, a problem that has plagued manufacturers for some time. Currently, the market urgently needs iron carbonyl removers with high iron carbonyl removal rates, strong raw material adaptability, and a wide operating temperature range.

[0003] Iron carbonyl and nickel carbonyl in syngas are generally formed by the reaction of carbon monoxide with iron and nickel elements on the surface of stainless steel pipes and equipment. Thermodynamically, under relatively low temperatures and extremely high pressures, the large amount of CO in the syngas corrodes the inner walls of pipes or equipment, generating iron carbonyl (which exists in three forms: Fe(CO)5, Fe(CO)8, and Fe(CO)9) and nickel carbonyl (Ni(CO)4). The generated iron and nickel carbonyl are carried by the gas flow into the next process, either the pre-reactor or the main methanol reactor. These reactors operate at high temperatures, typically 190-200℃ initially and later reaching 300-320℃. At this temperature, the iron and nickel carbonyl formed under low temperature and high pressure undergo high-temperature decomposition, depositing the iron and nickel on the surface of the methanol catalyst, while the CO returns to the main gas flow. The carbonyl iron and carbonyl nickel deposited on the methanol catalyst after decomposition are both important components. Iron is a common active component in Fischer-Tropsch synthesis, while nickel is an active component in hydrogenation. These components can trigger many side reactions and continuous reactions, such as (1) the formation of hydrocarbons; (2) the chain growth reaction to form paraffinic hydrocarbons; and (3) the formation of alcohols. These impurities not only increase the difficulty of separation, but the iron and nickel impurities themselves also affect the purity of the product, causing the crude methanol product to turn yellow.

[0004] Therefore, in order to ensure the stable long-term operation of the unit, extend the life of the methanol catalyst, or improve the quality of crude methanol, it is imperative to conduct research on a decarbonylation iron and nickel protective agent. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low removal rate, short lifespan, and complex preparation process of existing gas decarbonylation iron-nickel protective agents. This invention provides a gas decarbonylation iron-nickel protective agent, its preparation method, and its application for removing decarbonylation iron-nickel from methanol synthesis gas. This gas decarbonylation iron-nickel protective agent has the advantages of high removal rate, long lifespan, and relatively simplified preparation process, making it particularly suitable for use in large-scale medium- and low-pressure methanol synthesis plants, especially in the now common million-ton-level large-scale methanol industrial production plants.

[0006] To achieve the above objectives, the present invention provides a gas decarbonylation iron-nickel protective agent, which comprises an active component and a carrier, wherein the active component comprises elemental copper and elemental zinc, and the carrier comprises natural kaolin.

[0007] A second aspect of the present invention provides a method for preparing the protective agent described herein, the method comprising:

[0008] (1) Natural kaolin is first roasted and shaped to obtain a carrier;

[0009] (2) The carrier is contacted with copper salt solution and zinc salt solution, and drained to obtain the protective agent precursor;

[0010] (3) The protective agent precursor is dried and then calcined to obtain the protective agent.

[0011] A third aspect of the present invention provides the application of the gas decarbonylation iron-nickel protective agent of the present invention in the removal of carbonyl iron-nickel from gases.

[0012] The fourth aspect of this invention provides a method for removing carbonyl iron and nickel from methanol synthesis gas. The method includes: pre-loading a protective agent product into a carbonyl iron and nickel purification reactor, and then purifying the gas at a temperature of 120-220°C, a pressure of 0.1-8 MPa, and a space velocity of 1000-22000 h⁻¹. -1 Under certain conditions, methanol synthesis reaction gas containing carbonyl iron-nickel is introduced to obtain methanol synthesis reaction gas with a carbonyl iron-nickel content ≤20ppb.

[0013] Compared with the prior art, the advantages of the present invention are as follows:

[0014] This invention provides a gaseous decarbonylation iron-nickel protective agent. The active components of this system are distributed between the kaolin support and attached to the support. The copper-zinc active system protective agent has good activity and higher decarbonylation iron-nickel capacity, which can better protect the long-term operation of the methanol synthesis catalyst. Kaolin has the characteristics of large specific surface area and many micropores, which can fully physically adsorb carbonyl iron-nickel, and then deposit it after catalytic dissociation at the copper-zinc active center.

[0015] The gaseous decarbonylation iron-nickel protective agent prepared by this invention has two reaction processes: physical adsorption with a large specific surface area and catalytic dissociation deposition. The protective agent has the characteristics of large adsorption capacity, good decarbonylation activity, and high carbonyl iron-nickel removal capacity. It is particularly suitable for use in large-scale methanol synthesis plants with medium and low pressure, especially in the currently common million-ton-level large-scale methanol industrial production plants. Detailed Implementation

[0016] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0017] The first aspect of the present invention provides a gas decarbonylation iron-nickel protective agent, the protective agent comprising an active component and a carrier, wherein the active component comprises elemental copper and elemental zinc, and the carrier comprises natural kaolin.

[0018] This invention provides a gaseous decarbonylation iron-nickel protective agent. The active components of this system are distributed between the kaolin support and attached to the support. The copper-zinc active system protective agent has good activity and higher decarbonylation iron-nickel capacity, which can better protect the long-term operation of the methanol synthesis catalyst. Kaolin has the characteristics of large specific surface area and many micropores, which can fully physically adsorb carbonyl iron-nickel, and then deposit it after catalytic dissociation at the copper-zinc active center.

[0019] According to a preferred embodiment of the present invention, the carrier has a water absorption rate of 30-90%, a pore volume of 0.20-0.60 mL / g, and a specific surface area of ​​50-360 m². 2 / g, with a strength of 30-500 N / cm. By adopting the aforementioned preferred method, the large specific surface area and numerous micropores of kaolinite are utilized to fully physically adsorb carbonyl iron-nickel, which is then catalytically dissociated at the copper-zinc active centers and deposited.

[0020] According to a preferred embodiment of the present invention, the active component exists in the form of an oxide. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity can be improved.

[0021] According to a preferred embodiment of the present invention, the molar ratio of copper oxide to zinc oxide is 2:1 to 5:2. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity can be further improved.

[0022] According to a preferred embodiment of the present invention, the natural kaolin contains 80% by weight or more of kaolin, preferably 80-90% by weight.

[0023] In this invention, the natural kaolin is a non-metallic mineral and is not 100% pure; it also contains other impurities, which are not within the scope of this experimental study and will not be described in detail here.

[0024] According to a preferred embodiment of the present invention, the protective agent comprises, by weight of total protective agent: 0.2-62.0 wt% copper oxide, 0.1-31.0 wt% zinc oxide, and 7-97.3 wt% carrier.

[0025] According to a preferred embodiment of the present invention, the protective agent comprises: 7.8-51.2 wt% copper oxide, 3.9-25.6 wt% zinc oxide, and 30.2-85.2 wt% carrier. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the de-ferro-nickel activity, and the carbonyl iron-nickel removal capacity can be further improved.

[0026] A second aspect of the present invention provides a method for preparing the protective agent described herein, the method comprising:

[0027] (1) Natural kaolin is first roasted and shaped to obtain a carrier;

[0028] (2) The carrier is contacted with copper salt solution and zinc salt solution, and drained to obtain the protective agent precursor;

[0029] (3) The protective agent precursor is dried and then calcined to obtain the protective agent.

[0030] The decarbonylated iron-nickel protective agent prepared by the method of this invention improves the protective agent while ensuring the improvement of its activity and decarbonylation capacity. It simplifies the protective agent preparation process, protects the activity and service life of subsequent methanol synthesis catalysts, and better meets the production requirements of long-term stable operation of industrial plants.

[0031] According to a preferred embodiment of the present invention, an auxiliary agent is added during the molding process, the auxiliary agent including a binder and / or a lubricant. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the activity of removing nickel iron, and the removal capacity of nickel carbonyl iron can be improved.

[0032] In this invention, the type of binder can be selected from a wide range, and commonly used types can be used. According to a preferred embodiment of this invention, the binder is selected from at least one of deionized water, cellulose, hydroxycellulose, and sodium cellulose. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the activity of removing iron and nickel, and the capacity for removing carbonyl iron and nickel can be improved.

[0033] In this invention, the range of types of lubricant that can be selected is relatively wide, and commonly used types can all be used in this invention. According to a preferred embodiment of this invention, the lubricant is selected from at least one of deionized water, guar gum powder, and graphite. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the activity of removing iron and nickel, and the removal capacity of carbonyl iron and nickel can be improved.

[0034] In this invention, after the calcination in step (1), the binder and / or lubricant preferred by this invention are added and calcined completely, leaving only graphite.

[0035] According to a preferred embodiment of the present invention, the natural kaolin needs to be pre-dried, crushed, and sieved through a 40-120 mesh before use. By adopting the aforementioned preferred embodiment, the surface area and micropores of the kaolin are increased, thereby improving the physical adsorption capacity of kaolin for carbonyl iron-nickel.

[0036] According to a preferred embodiment of the present invention, the contact method is an impregnation method, in which a copper-zinc soluble solution is impregnated onto a natural kaolin molding carrier at a certain concentration to obtain a protective agent precursor. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the iron-nickel removal activity, and the carbonyl iron-nickel removal capacity are further improved.

[0037] According to a preferred embodiment of the present invention, the remaining liquid after impregnation can be recycled and reused.

[0038] In this invention, the range of copper salts that can be selected is relatively wide, and commonly used types can all be used in this invention. According to a preferred embodiment of this invention, the copper salt is selected from at least one of copper nitrate, basic copper carbonate, copper chloride, and copper sulfate.

[0039] According to a preferred embodiment of the present invention, the concentration of the copper salt solution is 0.2-3.0 mol / L. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the activity of removing iron and nickel, and the removal capacity of carbonyl iron and nickel are further improved.

[0040] In this invention, the range of zinc salts that can be selected is relatively wide, and commonly used types can all be used in this invention. According to a preferred embodiment of this invention, the zinc salt is selected from at least one of zinc nitrate, basic zinc carbonate, zinc chloride, and zinc sulfate.

[0041] According to a preferred embodiment of the present invention, the concentration of the zinc salt solution is 0.1-2.0 mol / L. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the deferro-nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0042] According to a preferred embodiment of the present invention, the conditions for the first calcination in step (1) include: a calcination temperature of 200-600℃, preferably 200-450℃. By adopting the aforementioned preferred conditions, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0043] According to a preferred embodiment of the present invention, the conditions for the first calcination in step (1) include: a calcination time of 20-240 min, preferably 30-160 min. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0044] According to a preferred embodiment of the present invention, the molding conditions in step (1) include: molding into a cylindrical and / or spherical shape, preferably with a carrier size of Φ3-10mm after molding. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0045] According to a preferred embodiment of the present invention, the contact conditions in step (2) include a temperature of 30-90°C.

[0046] According to a preferred embodiment of the present invention, the contact conditions in step (2) include a time of 30-120 min. By adopting the aforementioned preferred embodiment, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0047] According to a preferred embodiment of the present invention, the conditions for draining in step (2) include: natural draining in the filter screen at room temperature, and the filter paper should not be wetted over a large area when wiped.

[0048] According to a preferred embodiment of the present invention, the drying conditions in step (3) include a drying temperature of 80-150°C. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0049] According to a preferred embodiment of the present invention, the drying conditions in step (3) include a drying time of 30-120 min. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0050] According to a preferred embodiment of the present invention, the conditions for the second calcination in step (3) include a calcination temperature of 200-350°C. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0051] According to a preferred embodiment of the present invention, the conditions for the second calcination in step (3) include a calcination time of 20-60 min. By adopting the aforementioned preferred method, the adsorption capacity of the protective agent, the de-ferric nickel activity, and the carbonyl iron-nickel removal capacity are further improved.

[0052] According to a preferred embodiment of the present invention, the roasting apparatus is a muffle furnace or a rotary kiln.

[0053] According to a preferred embodiment of the present invention, the molding condition is tableting.

[0054] A third aspect of the present invention provides the application of the gas decarbonylation iron-nickel protective agent of the present invention in the removal of carbonyl iron-nickel from gases.

[0055] The decarbonylated iron-nickel protective agent prepared by the method of this invention has a relatively simple preparation process. The copper-zinc active system protective agent has good activity and higher decarbonylated iron-nickel capacity, which can better protect the long-term operation of methanol synthesis catalyst.

[0056] According to a preferred embodiment of the present invention, the gas is methanol synthesis gas.

[0057] The fourth aspect of this invention provides a method for removing carbonyl iron and nickel from methanol synthesis gas. The method includes: pre-loading a protective agent product into a carbonyl iron and nickel purification reactor, and then purifying the gas at a temperature of 120-220°C, a pressure of 0.1-8 MPa, and a space velocity of 1000-22000 h⁻¹. -1 Under certain conditions, methanol synthesis reaction gas containing carbonyl iron-nickel is introduced to obtain methanol synthesis reaction gas with a carbonyl iron-nickel content ≤20ppb.

[0058] The protective agent described in this invention has a high specific surface area, more adsorption sites for Fe(CO)5(g) and Ni(CO)4(g), and a higher probability of adsorption during molecular collisions. The active center metal is more widely distributed on the large specific surface area kaolinite support, and the removal level of carbonyl iron and nickel can reach ppb level, with higher removal precision.

[0059] According to a preferred embodiment of the present invention, the protective agent is the protective agent described in the present invention.

[0060] In this invention, gaseous Fe(CO)5(g) and Ni(CO)4(g) are physically adsorbed at high specific surface area adsorption sites using this type of decarbonylated iron protective agent. The adsorbed molecules migrate to the solid surface and then undergo catalytic dissociation reaction at the active sites at 100-220℃. Fe and Ni atoms are deposited in solid form on the microscopic surface of the solid protective agent, while CO returns to the main gas flow and continues to participate in the completion of its target reaction process.

[0061] Fe(CO)₅(g) → Fe(s) + 5CO(g)↑

[0062] Ni(CO)₄(g) → Ni(s) + 4CO(g)↑

[0063] The gaseous decarbonylation iron-nickel protective agent prepared by this invention has two reaction processes: physical adsorption with a large specific surface area and catalytic dissociation deposition. The protective agent has the characteristics of large adsorption capacity, good decarbonylation activity, and high carbonyl iron-nickel removal capacity. It is particularly suitable for use in large-scale methanol synthesis plants with medium and low pressure, especially in the currently common million-ton-level large-scale methanol industrial production plants.

[0064] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention.

[0065] Unless otherwise specified, all conditions in the examples shall be performed under standard conditions or conditions recommended by the manufacturer. Unless otherwise stated, all raw materials used in the examples are commercially available products.

[0066] In this invention, the specific surface area of ​​the carrier is obtained by testing with an F-Sorb 2400-BET fully automatic specific surface area analyzer.

[0067] Example 1

[0068] Natural kaolin is first calcined at 300℃ for 80 minutes in a muffle furnace or rotary kiln, then sieved through a 40-mesh sieve. Deionized water and guar gum powder are added, and the mixture is then pressed into tablets to obtain a carrier. The carrier size is Φ4.5-5.5mm. The carrier (80% by weight of natural kaolin, 20% by weight of deionized water and guar gum powder, with a mass ratio of 1:1) has a water absorption rate of 80%, a pore volume of 0.20mL / g, and a specific surface area of ​​350m². 2 / g, with a strength of 260 N / cm, the carrier was then added to a mixed solution of 0.5 mol / L copper nitrate aqueous solution (copper concentration of 0.34 mol / L) and zinc nitrate aqueous solution (zinc concentration of 0.16 mol / L) for excess impregnation reaction. The impregnation temperature was 30℃ and the impregnation time was 110 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. The protective agent precursor was dried at 120℃ for 40 min and then calcined at 300℃ for 40 min to prepare the protective agent sample 1, in which copper oxide 39.0 wt%, zinc oxide 19.5 wt%, carrier 41.5 wt%, and the molar ratio of CuO to ZnO was 2:1.

[0069] Example 2

[0070] Natural kaolin is first calcined at 200℃ for 150 minutes in a muffle furnace or rotary kiln, then sieved through an 80-mesh sieve. Cellulose and guar gum powder are added, and the mixture is then pressed into tablets to obtain a carrier (90% by weight of natural kaolin (80% by weight), 10% by weight of cellulose and guar gum powder (cellulose to guar gum powder mass ratio 1:1)). The carrier size is Φ4.5-5.5mm, the water absorption rate is 50%, the pore volume is 0.30mL / g, and the specific surface area is 290m². 2 / g, with a strength of 150 N / cm, the carrier was then added to a mixed solution of 2.5 mol / L copper nitrate aqueous solution (copper concentration 1.7 mol / L) and zinc nitrate aqueous solution (zinc concentration 0.8 mol / L), and an excess impregnation reaction was carried out. The impregnation temperature was 65℃ and the impregnation time was 80 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recovered and reused. The protective agent precursor was dried at 60℃ for 80 min and then calcined at 350℃ for 30 min to prepare methanol synthesis decarbonylated iron-nickel protective agent sample 2, in which copper oxide 22.5 wt%, zinc oxide 9.8 wt%, carrier 67.7 wt%, and the molar ratio of CuO to ZnO was 2.3:1.

[0071] Example 3

[0072] Natural kaolin was first calcined at 600℃ for 40 minutes in a muffle furnace or rotary kiln, then sieved through a 120-mesh sieve. Hydroxycellulose and graphite were then added, and the mixture was pressed into sheets to obtain a carrier (85% by weight of natural kaolin (90% by weight), 15% by weight of hydroxycellulose and graphite). The carrier size was Φ4.5-5.5 mm, the water absorption rate was 35%, the pore volume was 0.55 mL / g, and the specific surface area was 220 m². 2 / g, with a strength of 450 N / cm, the carrier was then added to a mixed solution of 2 mol / L copper nitrate aqueous solution (copper concentration of 1.4 mol / L) and zinc nitrate aqueous solution (zinc concentration of 0.6 mol / L) for excess impregnation reaction. The impregnation temperature was 90℃ and the impregnation time was 35 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. The protective agent precursor was dried at 30℃ for 115 min and then calcined at 220℃ for 60 min to prepare the protective agent sample 3, which contained 50.0 wt% copper oxide, 20 wt% zinc oxide, 29.0 wt% carrier, 1 wt% graphite, and the molar ratio of CuO to ZnO was 5:2.

[0073] Example 4

[0074] Natural kaolin was first calcined at 350℃ for 60 minutes in a muffle furnace or rotary kiln, sieved through a 100-mesh sieve, and then hydroxycellulose and graphite were added before being pressed into sheets to obtain a carrier (85% by weight of natural kaolin (80% by weight), 14% by weight of hydroxycellulose and graphite (mass ratio of hydroxycellulose to graphite is 1:1)). The carrier size was Φ4.5-5.5mm, with a water absorption rate of 78%, a pore volume of 0.25mL / g, and a specific surface area of ​​240m². 2 / g, with a strength of 250 N / cm, the carrier was then added to a mixed solution of 1.5 mol / L copper nitrate aqueous solution (copper concentration of 1.0 mol / L) and zinc nitrate aqueous solution (zinc concentration of 0.5 mol / L) for excess impregnation reaction. The impregnation temperature was 60℃ and the impregnation time was 50 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. After drying at 120℃, it was calcined again at 350℃ for 70 min to prepare the protective agent sample 4, which contained 45.6 wt% copper oxide, 19.0 wt% zinc oxide, 24.4 wt% carrier, 1 wt% graphite, and the molar ratio of CuO to ZnO was 2.4:1.

[0075] Example 5

[0076] Natural kaolin was first calcined at 300℃ for 80 minutes in a muffle furnace or rotary kiln, then sieved through a 40-mesh sieve. Deionized water and guar gum powder were added, and the mixture was then pressed into tablets to obtain a carrier. The carrier size was Φ4.5-5.5mm. The carrier (82% by weight of natural kaolin, 80% by weight of kaolin, 18% by weight of deionized water and guar gum powder) had a water absorption rate of 78%, a pore volume of 0.25mL / g, and a specific surface area of ​​290m². 2 / g, with a strength of 250 N / cm, the carrier was then added to a mixed solution of 3.0 mol / L copper nitrate aqueous solution (copper concentration of 2.0 mol / L) and zinc nitrate aqueous solution (zinc concentration of 1.0 mol / L) for excess impregnation reaction. The impregnation temperature was 30℃ and the impregnation time was 110 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. The protective agent precursor was dried at 120℃ for 40 min and then calcined at 300℃ for 40 min to prepare the protective agent sample 5, which contained 39.0 wt% copper oxide, 18.6 wt% zinc oxide, 41.4 wt% carrier, and a CuO:ZnO molar ratio of 2.1:1.

[0077] Example 6

[0078] Natural kaolin was first calcined at 300℃ for 80 minutes in a muffle furnace or rotary kiln, then sieved through a 40-mesh sieve. Deionized water was then added, and the mixture was pressed into tablets to obtain a carrier. The carrier size was Φ4.5-5.5mm. The carrier (85% by weight of natural kaolin, 80% by weight of kaolin, 15% by weight of deionized water) had a water absorption rate of 81%, a pore volume of 0.26mL / g, and a specific surface area of ​​276m². 2 / g, with a strength of 240 N / cm, the carrier was then added to a mixed solution of 3.0 mol / L copper nitrate aqueous solution (copper concentration of 2.0 mol / L) and zinc nitrate aqueous solution (zinc concentration of 1.0 mol / L) for excess impregnation reaction. The impregnation temperature was 30℃ and the impregnation time was 110 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. The protective agent precursor was dried at 120℃ for 40 min and then calcined at 300℃ for 40 min to prepare the protective agent sample 6, which contained 39.0 wt% copper oxide, 23.4 wt% zinc oxide, 37.6 wt% carrier, and a CuO:ZnO molar ratio of 5:3.

[0079] Example 7

[0080] Natural kaolin is first calcined at 300℃ for 80 minutes in a muffle furnace or rotary kiln, then sieved through a 40-mesh sieve. Deionized water and guar gum powder are added, and the mixture is then pressed into tablets to obtain a carrier. The carrier size is Φ4.5-5.5mm. The carrier (80% by weight of natural kaolin, 20% by weight of deionized water and guar gum powder) has a water absorption rate of 70%, a pore volume of 0.20mL / g, and a specific surface area of ​​300m². 2 / g, with a strength of 260 N / cm, the carrier was then added to a mixed solution of 0.5 mol / L copper nitrate aqueous solution (copper concentration of 0.33 mol / L) and zinc nitrate aqueous solution (zinc concentration of 0.17 mol / L) for excess impregnation reaction. The impregnation temperature was 30℃ and the impregnation time was 110 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining impregnation liquid was recycled and reused. The protective agent precursor was dried at 120℃ for 40 min and then calcined at 300℃ for 40 min to prepare the protective agent sample 7, which contained 39.0 wt% copper oxide, 19.5 wt% zinc oxide, 41.5 wt% carrier, and a CuO to ZnO molar ratio of 2:1.

[0081] Comparative Example 1

[0082] The pseudoboehmite was calcined at 400℃ for 40 minutes in a muffle furnace or rotary kiln, sieved through an 80-mesh sieve, and then hydroxyl cellulose sheets were added to form a molded carrier (80% by weight of pseudoboehmite, 20% by weight of hydroxyl cellulose and hydroxyl cellulose). The carrier had a water absorption rate of 30%, a pore volume of 0.56 mL / g, and a specific surface area of ​​120 m². 2 / g, with a strength of 260 N / cm, was added to a 3.0 mol / L mixed nitrate aqueous solution of Cu and Zn for excess impregnation reaction. The impregnation temperature was 30℃ and the impregnation time was 50 min. The impregnated precursor was taken out and allowed to drain naturally. The remaining liquid was recycled and reused. After drying at 120℃, it was calcined at 350℃ for 80 min to prepare sample 8, a decarbonylated iron-nickel protective agent for methanol synthesis.

[0083] Comparative Example 2

[0084] γ-Al₂O₃ was sieved through a 100-mesh sieve, and then hydroxyl cellulose was added and compressed into tablets to obtain a well-formed γ-Al₂O₃ carrier (γ-Al₂O₃ 85% by weight, hydroxyl cellulose 15% by weight). The carrier had a water absorption rate of 35%, a pore volume of 0.45 mL / g, and a specific surface area of ​​160 m². 2 / g, with a strength of 280 N / cm, was added to a 2.5 mol / L Zn nitrate aqueous solution for excess impregnation reaction. The impregnation temperature was 50℃ and the impregnation time was 50 min. The impregnated precursor was removed and allowed to drain naturally. The remaining impregnation liquid was recovered and reused. After drying at 120℃, it was calcined at 350℃ for 120 min to prepare Sample 9, a decarbonylated iron-nickel protective agent for methanol synthesis.

[0085] Comparative Example 3

[0086] Natural kaolin was first calcined at 300℃ for 80 minutes in a muffle furnace or rotary kiln, sieved through a 40-mesh sieve, and then deionized water was added to form a tablet to obtain a carrier (80% by weight of natural kaolin, 20% by weight of deionized water). The carrier had a water absorption rate of 40%, a pore volume of 0.50 mL / g, and a specific surface area of ​​130 m². 2 / g, with a strength of 150 N / cm, the carrier was then added to an aqueous solution of 0.5 mol / L copper nitrate for excess impregnation reaction at 30℃ for 110 min. The impregnated precursor was removed and allowed to drain naturally to obtain the protective agent precursor. The remaining liquid was recycled and reused. The protective agent precursor was dried at 120℃ for 40 min and then calcined at 300℃ for 40 min to prepare the protective agent sample 10, which contained 39.0 wt% copper oxide and 61 wt% carrier.

[0087] Test example:

[0088] The protective agent samples (samples 1-10) were pre-loaded into a carbonyl iron-nickel purification reactor and subjected to a temperature of 120-220℃, a pressure of 6.9 MPa, and a space velocity of 10000 h⁻¹. -1 A methanol synthesis reaction gas containing carbonyl iron-nickel is introduced to obtain a methanol synthesis reaction gas with a carbonyl iron-nickel content ≤20 ppb. The removal rate in this invention is calculated as: (Carbonyl iron-nickel content in the inlet synthesis gas - Carbonyl iron-nickel content in the outlet synthesis gas) / Carbonyl iron-nickel content in the inlet synthesis gas.

[0089] Table 1. Physicochemical data and carbonyl iron-nickel removal performance of the protective agent samples

[0090]

[0091] As can be seen from the data in Table 1, the embodiment of this invention, which uses active components copper and zinc loaded on a kaolin carrier with a large specific surface area, has a higher specific surface area, a better carbonyl iron-nickel removal rate, and a wider temperature adaptability range, showing significantly better removal performance compared to the comparative example. Furthermore, it also demonstrates good performance in removing carbonyl iron-nickel from non-methanol gases.

[0092] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for removing carbonyl iron-nickel from syngas used in methanol production, characterized in that, The method comprises: preloading the protective agent end product into a carbonyl iron-nickel purification reactor, and under the conditions of a temperature of 120-220 DEG C, a pressure of 0.1-8 MPa, and an air speed of 1000-22000 h -1 Under the conditions, the synthesis gas containing carbonyl iron-nickel for preparing methanol is introduced to obtain the synthesis gas containing ≤20 ppb carbonyl iron-nickel for preparing methanol. The protective agent comprises an active component and a carrier. The active component contains elemental copper and elemental zinc, and the active component exists in the form of oxides, with a molar ratio of copper oxide to zinc oxide of (2:1)-(5:2). The carrier contains natural kaolin.

2. The method according to claim 1, wherein, The carrier has a water absorption rate of 30-90%, a pore volume of 0.20-0.60 mL / g, and a specific surface area of ​​50-360 m². 2 / g, with a strength of 30-500N / cm.

3. The method according to claim 1, wherein, The natural kaolin clay contains more than 80% by weight of kaolin.

4. The method according to claim 3, wherein, The natural kaolin contains 80-90% kaolin by weight.

5. The method according to claim 1, wherein, The protective agent comprises, by total mass, 0.2-62.0 wt% copper oxide, 0.1-31.0 wt% zinc oxide, and 7-97.3 wt% carrier.

6. The method according to claim 4, wherein, The protective agent comprises, by total mass, 7.8-51.2 wt% copper oxide, 3.9-25.6 wt% zinc oxide, and 30.2-85.2 wt% carrier.

7. The method according to claim 1, wherein, The method for preparing the protective agent includes: (1) Natural kaolin is first roasted and shaped to obtain a carrier; (2) The carrier is contacted with copper salt solution and zinc salt solution, and drained to obtain the protective agent precursor; (3) The protective agent precursor is dried and then calcined to obtain the protective agent.

8. The method according to claim 7, wherein, The copper salt is selected from at least one of copper nitrate, basic copper carbonate, copper chloride, and copper sulfate; and / or The concentration of the copper salt solution is 0.2-3.0 mol / L; and / or The zinc salt is selected from at least one of zinc nitrate, basic zinc carbonate, zinc chloride, and zinc sulfate; and / or The concentration of the zinc salt solution is 0.1-2.0 mol / L.

9. The method according to claim 7, wherein, The conditions for the first calcination in step (1) include: a calcination temperature of 200-600℃; and / or a calcination time of 20-240 min; and / or The molding conditions described in step (1) include molding into a cylindrical and / or spherical shape.

10. The method according to claim 9, wherein, The conditions for the first calcination in step (1) include: a calcination temperature of 200-450℃; and / or a calcination time of 30-160 min; and / or The molding conditions mentioned in step (1) include: the size of the carrier after molding is Φ3-10mm.

11. The method according to claim 7, wherein, The contact conditions described in step (2) include: a temperature of 30-90°C and / or a time of 30-120 min; and / or The conditions for draining in step (2) include: natural draining in the filter screen at room temperature, and no large area of ​​the filter paper should be wetted when wiped.

12. The method according to claim 7, wherein, The drying conditions described in step (3) include: a drying temperature of 80-150℃, and / or a drying time of 30-120 min; and / or The conditions for the second roasting in step (3) include: a roasting temperature of 200-350℃ and / or a roasting time of 20-60min.

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