Preparation method of renewable low-temperature gas adsorbent for removing hydrogen sulfide

Abstract

The invention relates to a preparation method of a sulfur removal adsorbent, in particular to a preparation method of a reproducible low-temperature gas adsorbent for removing hydrogen sulfide, which comprises the following steps: loading a molded molecular sieve and an oxide precursor salt; according to the loading method, the operation process is simple, the active component can be efficiently loaded on the carrier, the loading capacity can be regulated and controlled, the impregnation liquid and the washing liquid can be recycled and efficiently utilized, and the preparation cost of the adsorbent is reduced. The invention also relates to a method for adsorbing hydrogen sulfide by the adsorbent and a method for regenerating the adsorbent after adsorbing hydrogen sulfide. The adsorbent carrier is a molded molecular sieve, and the active component is a transition metal oxide. The hydrogen sulfide adsorbent provided by the invention has high sulfur capacity and good deep desulfurization effect, can be regenerated for multiple times, is mild in operation in the regeneration process, and is used for removing hydrogen sulfide from gases such as blast furnace gas, coke oven gas or fuel gas.

Description

Technical Field

[0001] The invention relates to a method for preparing a desulfurization adsorbent, in particular to a method for preparing a low-temperature gas adsorbent capable of regenerating and removing hydrogen sulfide. Background Art

[0002] Hydrogen sulfide (H2S) mainly comes from nature and human activities. Nature mainly releases H2S through hot springs, oceans, volcanic eruptions, wetlands, vegetation and soil. H2S mainly exists in various industrial processes such as petroleum refining, biopharmaceuticals, steel smelting, food processing and papermaking. A small amount of hydrogen sulfide is also produced in daily life. As a toxic sulfur-containing gas, H2S not only harms human physical and mental health, but also has a certain impact on the environment and industrial production. In the chemical production process using coal, oil and natural gas as raw materials, a small amount of inorganic sulfur-containing gas will be produced, of which H2S accounts for the largest proportion. In the subsequent chemical production process, the H2S in the gas will corrode the pipeline during transportation, affect the accuracy of instruments and meters, poison the catalyst during processing and purification, and generate toxic SO2 during use. With the gradual strengthening of environmental protection policies, it is imperative to remove H2S from the mixed gas, and the use value of the treated gas will be greatly improved. Therefore, the removal of hydrogen sulfide has important economic and social value.

[0003] H2S removal technology can be divided into wet desulfurization and dry desulfurization according to the phase of the desulfurizer. Compared with wet desulfurization, dry desulfurization has the advantages of high desulfurization accuracy, low corrosiveness, no secondary pollution, easy operation and low cost. In industry, the hydrogen sulfide in the mixed gas is usually reduced to the ppb level, so dry desulfurizer is more suitable for industrial treatment.

[0004] For example, patent US11745162B2 discloses a regenerable hydrogen sulfide adsorbent and a preparation method thereof. The preparation method specifically comprises: 1) combining aluminate as an active component with activated alumina as a carrier by impregnation, spraying or solid phase mixing to obtain a precursor; 2) aging and drying the precursor, and finally calcining to obtain an adsorbent; 3) forming measures to make the adsorbent present a specific size and shape to meet industrial application requirements. Compared with the prior art, the adsorbent obtained according to the present invention can effectively remove hydrogen sulfide at the material inlet, with a concentration adaptation range of 0-1000 ppm and an effective removal accuracy of 0.1 ppm and below. US7833316B2 discloses an adsorbent composition comprising a porous silica carrier impregnated with a mixture of zinc oxide and copper-based materials. The adsorbent composition can be used for systems and methods for removing sulfur compounds from a gas stream, and is a promising renewable heat-absorbing material suitable for low-temperature environments, such as in-line gas filters at fuel cell stack temperatures and protective filters during the startup of fuel cell systems. CN112619590A discloses a regenerable hydrogen sulfide adsorbent and a preparation method thereof, wherein the concentration range used is 0-1000 ppm, the desulfurization accuracy is below 0.1 ppm, and the adsorption capacity for hydrogen sulfide is restored after regeneration in an inert or reducing atmosphere at a regeneration temperature of 180-300 °C. CN112439383A discloses a preparation method for a hydrogen sulfide adsorbent, wherein the exfoliated bentonite and attapulgite support each other during the synthesis process to form a combined macroporous structure, and manganese hydroxide is oxidized to manganese oxide to obtain an alkaline iron-manganese compound loaded with macroporous minerals, and the sulfur capacity can reach up to 258 mg / g. CN 111013536 A discloses a medium-temperature regenerable hydrogen sulfide adsorbent preparation and a cyclic desulfurization method thereof, wherein activated carbon from coal or biomass is placed in a reactor (such as a high-pressure reactor), the reactor is heated to 50-200 °C, and the reactor is vacuumed for more than 10 min. A mixed gas of nitrogen and fluorine is introduced into the reactor, and the activated carbon is fluorinated at 40-120°C for more than 5 minutes to obtain fluorinated activated carbon. Dimethyl silicone oil and ethyl orthosilicate are added to a solution box as a mixed liquid, and the solution box is placed in a reactor, and heated at a constant temperature of 150-500°C to allow the fluorinated activated carbon to react with the mixed liquid steam for more than 20 minutes to obtain a medium-temperature regenerable hydrogen sulfide adsorbent. The adsorbent of the present invention has the advantages of adsorption-desorption regeneration function and high hydrogen sulfide recovery rate.

[0005] The above-mentioned regenerable adsorbents can produce an effect on the adsorption of H2S to a certain extent, but there are still certain obstacles to their industrial application, such as high manufacturing cost of the adsorbent, complicated preparation process, only being able to be used at high temperature, low desulfurization accuracy, and harsh regeneration conditions.

[0006] Therefore, how to solve the problems of high operating temperature, high cost, low desulfurization accuracy and harsh regeneration conditions existing in existing hydrogen sulfide adsorbents is a direction that urgently needs to be studied.

[0007] Therefore, designing a renewable industrial adsorbent that has a large sulfur capacity for hydrogen sulfide adsorption at low temperature and can meet the requirements of high sulfur accuracy and low cost is an issue that urgently needs to be studied and solved. Summary of the invention

[0008] The purpose of the present invention is to provide a method for preparing a low-temperature gas adsorbent for regenerating hydrogen sulfide removal, in which a molecular sieve is formed and loaded with an oxide precursor salt; the active component is loaded on a carrier, and the impregnation liquid and the washing liquid can be recycled and efficiently utilized, thereby reducing the preparation cost of the adsorbent. The hydrogen sulfide adsorbent prepared by the present invention has a high sulfur capacity, can be deeply desulfurized, and can be regenerated multiple times, and is effective in removing hydrogen sulfide from gases such as blast furnace gas, coke oven gas or fuel gas.

[0009] The objective of the present invention is achieved through the following technical solutions: A method for preparing a low-temperature gas adsorbent capable of regenerating and removing hydrogen sulfide, the method comprising the following preparation process: First, the formed molecular sieve is mixed with a transition metal salt precursor and a solvent to carry out a loading reaction, filtration, washing, drying and calcination. The formed molecular sieve undergoes a complete operation of loading reaction, filtration, washing, drying and calcination once, which is recorded as one loading operation, and the adsorbent obtained is a primary loading adsorbent; The specific steps include: (1) dissolving a transition metal salt precursor in a solvent to obtain an impregnation solution, and impregnating the formed molecular sieve in the impregnation solution at 40-60°C for 2-4 hours. After the reaction is completed, taking out the formed molecular sieve, filtering it, and washing it for 0-5 minutes with a washing reagent at the same temperature as during the impregnation operation; (2) The washed shaped molecular sieve is dried at 120-140°C, and the dried product is calcined in an air atmosphere for 3-5 hours at a calcination temperature of 200-400°C; (3) replenishing the impregnation solution with a metal salt precursor and water (using a washing agent used to wash the formed molecular sieve) to the previous concentration, repeating the loading operation in the above steps (1)-(2), and continuously increasing the content of the active ingredient in the adsorbent to obtain the desired adsorbent; the adsorbent comprises the formed molecular sieve and the active component loaded on the carrier; the carrier is the molecular sieve, and the active component is the metal oxide; The loading operation is repeated 1 to 5 times; the heating rate of the drying and calcining temperature is 5 to 10°C / min.

[0010] The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the molded molecular sieve is a commercially available cheap molded molecular sieve, and the shape of the molded molecular sieve includes a sphere with a size of Ф1.5-Ф6 mm or a strip with a diameter of Ф1.5-Ф6 mm and a length of 1.5-5 mm; preferably, the molded shape is a sphere with a size of 3-5 mm.

[0011] The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the molded molecular sieve comprises a molecular sieve and a binder, wherein the molecular sieve content is 50-90% by weight, and the binder content is 10-50% by weight; preferably, the molecular sieve content is 80% by weight, and the binder content is 20% by weight; the molecular sieve is an A-type molecular sieve, an X-type molecular sieve, a Y-type molecular sieve, an M-type molecular sieve, or a high-silicon molecular sieve; preferably, the molecular sieve is an X-type molecular sieve.

[0012] In the method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the general chemical formula of the molecular sieve is xAl2O3∙ySiO2, y:x=0-100; preferably y:x=10-50.

[0013] The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the metal in the metal oxide includes one or a combination of at least two of the fourth period, fifth period or sixth period transition metals, preferably one or a combination of at least two of titanium, vanadium, manganese, iron, nickel, copper or zinc, and more preferably copper.

[0014] In the method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the transition metal salt precursor includes one or a combination of at least two of nitrate, chloride, acetate or sulfate; the solvent used includes water, ethanol, methanol, preferably solvent water; preferably, the mixing process is accompanied by stirring, and the specific mixing method includes: (a) dissolving a transition metal precursor salt in a solvent to obtain a transition metal salt solution; (b) blending the formed molecular sieve and the impregnation solution; Preferably, the concentration of the transition metal salt solution in step (a) is 0.5 mol / L-5 mol / L, or 1-4 mol / L; The shaped molecular sieve is mixed with a solution containing a transition metal salt by impregnation, ion exchange or spraying to load the metal salt on the molecular sieve carrier, preferably by impregnation.

[0015] In the method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide, the immersion temperature of the carrier and the transition metal salt precursor solution is 30-90°C, preferably 40-80°C; Preferably, the volume ratio of the formed molecular sieve to the impregnation liquid is 1:(1-20), or 1:(1-10); Preferably, the impregnation reaction time is 1-5 h, or 2-4 h; The preferred washing reagent is water, ethanol, methanol, preferably water; Preferably, the number of washing operations is 0-10 times, or 0-5 times; Preferably, the single dosage of the washing agent is 1-10 times, or 1-5 times, the volume of the adsorbent; Preferably, the temperature of the washing agent is room temperature to 90°C, or room temperature to 80°C; Preferably, the drying temperature of the washed formed molecular sieve is 80-200°C, preferably 120-140°C; Preferably, the drying time of the formed molecular sieve after impregnation is 1-10 h, or 3-5 h; The calcination temperature is preferably 250-600°C, or 300-400°C; The preferred calcination time is 2-6 h, or 3-5 h; The preferred calcining atmosphere is air atmosphere; Preferably, the number of adsorbent loading operations is 1-6 times, or 1-4 times.

[0016] The method for preparing a low-temperature gas adsorbent capable of regenerating hydrogen sulfide removal has a temperature range of 60-160°C for low-temperature hydrogen sulfide removal.

[0017] The advantages and effects of the present invention are: (1) The present invention provides a regenerable adsorbent for removing hydrogen sulfide at low temperature. The adsorbent uses a composite molecular sieve with a large specific surface area as a carrier, which improves the uniform distribution of active components in the adsorbent and effectively improves the utilization rate of active components. The loading amount can be regulated, and the adsorbent can achieve low-temperature fine desulfurization, and the desulfurization effect can reach ppb level. It can also be regenerated and recycled. The regeneration temperature is low, simple and easy to operate, and effectively reduces the industrial use cost.

[0018] (2) The adsorbent provided by the present invention has a simple preparation process, does not require the use of organic hazardous reagents during the preparation process, and can be recycled and reused, thereby reducing the generation of solid waste and is an environmentally friendly material.

[0019] (3) The adsorbent provided by the present invention has strong application value and significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a comparison chart of hydrogen sulfide adsorption performance of adsorbents AD prepared in Examples 1-4 of the present invention; Figure 2This is a comparison chart of hydrogen sulfide adsorption performance of adsorbent AP prepared in Examples 1-16 of the present invention; Figure 3 This is a comparison chart of hydrogen sulfide adsorption performance of adsorbent A, adsorbent Q and adsorbent R prepared in Example 1, Example 17 and Example 18 of the present invention; Figure 4 This is a comparison chart of the hydrogen sulfide adsorption performance of adsorbent A, adsorbent S and adsorbent T prepared in Examples 1, 19 and 20 of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below.

[0022] The present invention provides a method for preparing a regenerable low-temperature hydrogen sulfide gas adsorbent, wherein the adsorbent comprises a carrier and an active component loaded on the carrier; The carrier is a molded molecular sieve, and the active component is a metal oxide. The regenerable low-temperature hydrogen sulfide gas adsorbent includes a molded molecular sieve and an active component loaded on the carrier, and the loading amount can be regulated. The reuse of the impregnation liquid and the washing reagent reduces the cumbersome operation and capital investment of the washing reagent after washing, while reducing the cost of using raw materials. The molecular sieve with a larger specific surface area effectively improves the utilization rate of the active component, and the adsorbent can achieve a larger sulfur capacity at low temperature, and the desulfurization accuracy can reach the ppb level. At the same time, regeneration and recycling can be achieved, which effectively reduces the preparation and use costs of the industrialized adsorbent, and has a strong market practical value. The adsorbent can be used directly, has a good deep desulfurization effect, can be regenerated multiple times, and the regeneration process is gentle and simple. The present invention adopts a commercially available cheap molded molecular sieve, which can reduce the subsequent molding cost of the adsorbent. In addition, the larger specific surface area of ​​the molecular sieve is conducive to the uniform distribution of the active component on the adsorbent.

[0023] As a preferred technical solution of the present invention, the shape and size of the molded molecular sieve is a sphere of Φ3-5mm, for example, it can be a sphere of Φ3mm, Φ3.5mm, Φ4mm, Φ4.5mm or Φ5mm. The preferred molecular sieve content and binder content ratio is (50-90 weight %): (10-50 weight %), wherein the molecular sieve content selection range "10-50 weight %" can be, for example, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, and the binder content selection range "10-50 weight %" can be, for example, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0024] If the molecular sieve content and the binder content ratio are large, that is, the molecular sieve content is too much, it is not conducive to the molding of the molecular sieve, and it is easy to cause the molecular sieve to pulverize, which is not conducive to the subsequent loading operation; if the molecular sieve content and the binder content ratio is too small, that is, the molecular sieve content is too little, the content of the carrier in the preparation process of the adsorbent is not enough to provide a large specific surface area, which is not conducive to the dispersion of the active component on the carrier. X-type molecular sieve is preferred.

[0025] The present invention adopts X molecular sieve with large specific surface area, so that the prepared adsorbent has a large loading area, which is conducive to the uniform dispersion of active components on the carrier. The preferred chemical formula of the molecular sieve is xAl2O3∙ySiO2, y:x=0-100; for example, it can be 1, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90 or 100, etc. Preferably y:x=10-50.

[0026] In the present invention, if the silicon-aluminum ratio is too small, that is, the silicon content in the molecular sieve is too little, it is not conducive to the thermal stability of the adsorbent; if the silicon-aluminum ratio is too large, that is, the aluminum content in the molecular sieve is too little, it is not conducive to increasing the specific surface area of ​​the adsorbent. In the preferred active component metal oxide, the metal includes any one or a combination of at least two of the fourth period, fifth period or sixth period transition metals, preferably any one or a combination of at least two of titanium, vanadium, manganese, iron, nickel, copper or zinc, and more preferably copper; copper, iron and zinc are present in the active component at the same time, which can play a synergistic role and is conducive to improving the hydrogen sulfide adsorption capacity per unit volume and mass of the active component of the adsorbent. The preferred atomic ratio of copper, iron and zinc is (1-0):(0-0.2):(0-0.2), wherein the selection range of copper "1-0" can be, for example, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 or 0, etc., the selection range of iron is "0.1-0.2", for example, 0, 0.1 or 0.2, etc., and the selection range of zinc is "0.1-0.2", for example, 0, 0.1 or 0.2, etc.

[0027] The present invention mixes the formed molecular sieve with the transition metal salt precursor and the solvent for loading reaction, filtering, washing, drying and roasting. The preparation process of the adsorbent is simple, no organic harmful reagents are needed in the preparation process, and it can be recycled and reused, reducing the generation of solid waste, and belongs to environmentally friendly materials. Its preparation belongs to dry desulfurization, which overcomes the problems of low desulfurization accuracy in wet desulfurization technology.

[0028] The molecular sieve carrier in the molded state has columnar and spherical shapes, and the preferred molded shape is spherical. The molded molecular sieve is spherical in shape, and the spherical shape with a larger surface area is more conducive to the impregnation liquid entering the molded adsorbent.

[0029] The transition metal precursor salt of the present invention includes any one of nitrate, chloride, acetate or sulfate, or a combination of at least two thereof; The solvent used includes water, ethanol, methanol, etc., preferably water; the present invention does not specifically limit water, and illustratively, it can be distilled water, for example.

[0030] Preferably, the mixing process is accompanied by stirring, and the specific method of mixing includes: (a) dissolving a transition metal precursor salt in a solvent to obtain an impregnation solution; (b) blending the shaped molecular sieve and the impregnation solution.

[0031] The present invention adopts this mixing method, which can fully mix the shaped molecular sieve and the transition metal to the maximum extent, which is beneficial to the dispersion of the metal loaded on the shaped molecular sieve.

[0032] Preferably, the concentration of the impregnation solution in step (a) is 1-4 mol / L, for example, 1 mol / L, 2 mol / L, 3 mol / L or 1:4 mol / L, etc. The molecular sieve in the molded state is loaded with the metal salt on the molecular sieve carrier by impregnation, ion exchange or spraying in a solution containing a transition metal salt, preferably by impregnation.

[0033] The load is treated by impregnation, which is simple to operate and has low equipment requirements. The impregnation temperature of the carrier and the transition metal salt precursor solution is preferably 40-80 ° C, for example, 40 ° C, 50 ° C, 60 ° C, 70 ° C or 80 ° C. The volume ratio of the formed molecular sieve and the impregnation solution is preferably 1: (1-10), for example, it can be 1: 1, 1: 2, 1: 3, 1: 4, 1: 5, 1: 6, 1: 7, 1: 8, 1: 9 or 1: 10, etc. The impregnation reaction time is 2-4 h, for example, it can be 2 h, 2.5 h, 3 h, 3.5 h or 4 h. The preferred washing reagent is water. The preferred number of washing operations is 0-5 times, for example, it can be 0, 1, 2, 3, 4 or 5 times; the preferred single amount of washing reagent is 1-5 times the volume of the adsorbent, for example, it can be 1, 2, 3, 4 or 5 times. Preferably, the temperature of the washing agent is room temperature to 80°C, for example, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C, preferably 40-80°C.

[0034] The room temperature in the present invention refers to 25±5°C, for example, it can be 20°C, 22°C, 24°C, 26°C, 28°C or 30°C.

[0035] Preferably, the drying temperature of the formed molecular sieve after impregnation is 120-140 ° C, for example, it can be 120 ° C, 125 ° C, 130 ° C, 135 ° C or 140 ° C; preferably, the drying time of the formed molecular sieve after impregnation is 3-10 h, for example, it can be 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, etc., preferably 3-5h; the calcination temperature is 250-600 ° C, for example, it can be 250 ° C, 300 ° C, 350 ° C, 400 ° C, 450 ° C, 500 ° C, 550 ° C or 600 ° C, preferably 200-400 ° C; In the present invention, if the calcination temperature is too low, the metal salt cannot be completely converted into an oxide with adsorption activity, and the hydrogen sulfide adsorption sulfur capacity is reduced; if the calcination temperature is too high, it is easy to cause the metal oxide to sinter and cause the particles to agglomerate, resulting in a reduction in adsorption centers, resulting in a decrease in the hydrogen sulfide adsorption sulfur capacity. The calcination time is 2-6 h, for example, it can be 2h, 3h, 4h, 5h or 6h, preferably 3-5 h; the calcination atmosphere is an air atmosphere.

[0036] The preparation method of the present invention comprises the following steps: (1) dissolving a transition metal salt precursor in a solvent to obtain an impregnation solution of a certain concentration, and immersing the formed molecular sieve in the impregnation solution at 40-80°C for 2-4 hours. After the reaction is completed, the formed molecular sieve is taken out and filtered, and washed with a washing agent at the same temperature as the impregnation operation for 0-5 minutes. (2) The washed shaped molecular sieve is dried at 120-140°C, and the dried product is calcined in an air atmosphere for 3-5 hours at a calcination temperature of 200-400°C; (3) The impregnation solution is supplemented with metal salt precursor and water (the washing reagent used to wash the formed molecular sieve can be used) to the previous concentration, and the loading operation of steps 1-2 is repeated to continuously increase the content of active ingredients in the adsorbent to obtain the desired adsorbent; The drying and calcining temperatures are increased at a rate of 5-10 °C / min.

[0037] In the present invention, 3-5 h, for example, can be 3 h, 3.5 h, 4 h, 4.5 h or 5 h, 120-140 ℃, for example, can be 120 ℃, 125 ℃, 130 ℃, 135 ℃ or 140 ℃, 200-400 ℃, for example, can be 200 ℃, 250 ℃, 300 ℃, 350 ℃ or 400 ℃.

[0038] Among them, the formed molecular sieve undergoes a complete operation of loading reaction, filtration, washing, drying and calcination, which is recorded as one loading operation, and the adsorbent obtained is a primary loaded adsorbent; the number of loading operations of the adsorbent is 1-4 times, for example, it can be 1, 2, 3 or 4 times, and the adsorbent obtained is distributed as a primary loaded adsorbent, a secondary loaded adsorbent, a tertiary loaded adsorbent or a quaternary loaded adsorbent.

[0039] The temperature range of the low-temperature removal of hydrogen sulfide in the present invention is 60-160°C, for example, it can be 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or 160°C.

[0040] The adsorbent of the present invention can remove hydrogen sulfide in the range of 60-160°C, and can remove nearly 100% of the hydrogen sulfide in the mixed gas. If the removal temperature is too high, although it will accelerate the desorption of hydrogen sulfide and appropriately increase the adsorption sulfur capacity of the adsorbent, it will increase industrial energy consumption and is not conducive to industrial use.

[0041] The adsorbent of the present invention is used to remove hydrogen sulfide from blast furnace gas, coke oven gas or fuel gas. In addition to hydrogen sulfide, blast furnace gas also contains oxygen, methane, hydrogen, carbon monoxide and carbon dioxide, and in addition to hydrogen sulfide, coke oven gas also contains oxygen, methane, hydrogen, carbon monoxide and carbon dioxide.

[0042] It should be noted that the use condition of the adsorbent provided by the present invention is 60-90°C, for example, it can be 60°C, 70°C, 80°C or 90°C.

[0043] When the adsorbent of the present invention is regenerated, the adsorbent after adsorption is heated in an atmosphere of 150-300°C to desorb the adsorbed hydrogen sulfide, thereby restoring the adsorption capacity of the adsorbent for hydrogen sulfide. The regeneration atmosphere used is selected from gases such as hydrogen, methane, carbon monoxide, carbon dioxide or oxygen after hydrogen sulfide is removed.

[0044] The numerical range of the present invention includes but is not limited to the point values ​​listed above, and also includes point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0045] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings. Example 1

[0046] This embodiment provides a regenerable low-temperature hydrogen sulfide gas adsorbent, the adsorbent comprising a shaped molecular sieve and an active component loaded on the carrier, the carrier is a molecular sieve; the active component is a metal oxide; The molded molecular sieve is a commercially available X-type molded molecular sieve, the weight ratio of the molecular sieve to the binder in the molded molecular sieve is 90:10, and the concentration of the impregnation solution, the impregnation temperature, and the number of loading operations are selected according to the required active ingredient content on the adsorbent.

[0047] The present invention also provides a method for preparing the above-mentioned regenerable adsorbent for removing hydrogen sulfide at low temperature, the preparation method comprising the following steps: (1) Dissolve 24.2 g of copper nitrate in 100 mL of distilled water to prepare a 1 mol / L copper nitrate solution; (2) Immerse 7.5 g of the formed molecular sieve in the above impregnation solution at 40 °C for 2 h, and immerse once. After the reaction is completed, take out the formed molecular sieve, filter it, and wash it with 40 °C water for 3 times; (3) The impregnated formed molecular sieve was placed in an oven at 120 °C for 4 h to dry, and then placed in a muffle furnace for calcination at 300 °C in an air atmosphere for 4 h. The calcination temperature was increased at a rate of 5 °C / min, and the load operation was 1 time. The sieve was 40 mesh to obtain the regenerable adsorbent for low-temperature removal of hydrogen sulfide, which was recorded as adsorbent A.

[0048] The adsorbent A provided in this embodiment can remove hydrogen sulfide at 80°C.

[0049] Example 2 The difference between this embodiment and embodiment 1 is that the loading operation is performed twice in step (3), and the adsorbent is recorded as adsorbent B.

[0050] The rest of the preparation methods and parameters were the same as those in Example 1.

[0051] Example 3 The difference between this embodiment and embodiment 1 is that the loading operation is performed three times in step (3), and the adsorbent is recorded as adsorbent C.

[0052] The rest of the preparation methods and parameters were the same as those in Example 1.

[0053] Example 4 The difference between this embodiment and embodiment 1 is that the loading operation in step (3) is performed 4 times, and the adsorbent is recorded as adsorbent D.

[0054] The rest of the preparation methods and parameters were the same as those in Example 1.

[0055] Example 5 The difference between this embodiment and embodiment 1 is that in step (1), 48.3 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a 2 mol / L copper nitrate solution, and the adsorbent is recorded as adsorbent E.

[0056] The rest of the preparation methods and parameters were the same as those in Example 1.

[0057] Example 6 The difference between this embodiment and embodiment 1 is that in step (1), 48.3 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 2 mol / L, and in step (3), the loading operation is performed twice. The adsorbent is recorded as adsorbent F.

[0058] The rest of the preparation methods and parameters were the same as those in Example 1.

[0059] Example 7 The difference between this embodiment and embodiment 1 is that in step (1), 48.3 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 2 mol / L, and in step (3), the loading operation is performed 3 times. The adsorbent is recorded as adsorbent G.

[0060] The rest of the preparation methods and parameters were the same as those in Example 1.

[0061] Example 8 The difference between this embodiment and embodiment 1 is that in step (1), 48.3 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 2 mol / L, and in step (3), the loading operation is performed 4 times. The adsorbent is recorded as adsorbent H.

[0062] The rest of the preparation methods and parameters were the same as those in Example 1.

[0063] Example 9 The difference between this embodiment and embodiment 1 is that in step (1), 72.5 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a 3 mol / L copper nitrate solution, and the adsorbent is recorded as adsorbent I.

[0064] The rest of the preparation methods and parameters were the same as those in Example 1.

[0065] Example 10 The difference between this embodiment and embodiment 1 is that in step (1), 72.5 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 3 mol / L, and in step (3), the loading operation is performed twice. The adsorbent is recorded as adsorbent J.

[0066] The rest of the preparation methods and parameters were the same as those in Example 1.

[0067] Embodiment 11 The difference between this embodiment and embodiment 1 is that in step (1), 72.5 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 3 mol / L, and in step (3), the loading operation is performed 3 times. The adsorbent is recorded as adsorbent K.

[0068] The rest of the preparation methods and parameters were the same as those in Example 1.

[0069] Example 12 The difference between this embodiment and embodiment 1 is that in step (1), 72.5 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 3 mol / L, and in step (3), the loading operation is performed 4 times. The adsorbent is recorded as adsorbent L.

[0070] The rest of the preparation methods and parameters were the same as those in Example 1.

[0071] Embodiment 13 The difference between this embodiment and embodiment 1 is that in step (1), 96.6 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 4 mol / L, and the adsorbent is recorded as adsorbent M.

[0072] The rest of the preparation methods and parameters were the same as those in Example 1.

[0073] Embodiment 14 The difference between this embodiment and embodiment 1 is that in step (1), 96.6 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 4 mol / L, and in step (3), the loading operation is performed twice. The adsorbent is recorded as adsorbent N.

[0074] The rest of the preparation methods and parameters were the same as those in Example 1.

[0075] Embodiment 15 The difference between this embodiment and embodiment 1 is that in step (1), 96.6 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 4 mol / L, and in step (3), the loading operation is performed 3 times. The adsorbent is recorded as adsorbent O.

[0076] The rest of the preparation methods and parameters were the same as those in Example 1.

[0077] Example 16 The difference between this embodiment and embodiment 1 is that in step (1), 96.6 g of copper nitrate is dissolved in 100 mL of distilled water to prepare a copper nitrate solution with a concentration of 4 mol / L, and in step (3), the loading operation is performed 4 times. The adsorbent is recorded as adsorbent P.

[0078] The rest of the preparation methods and parameters were the same as those in Example 1.

[0079] Embodiment 17 The difference between this embodiment and embodiment 1 is that in step (2), the adsorbent is immersed at 60°C for 2 h, immersed once, and washed with 60°C water. The adsorbent is recorded as adsorbent Q.

[0080] The rest of the preparation methods and parameters were the same as those in Example 1.

[0081] Embodiment 18 The difference between this embodiment and embodiment 1 is that step (2) is to immerse at 80°C for 2 h, immerse once, and wash with 80°C water. The adsorbent is recorded as adsorbent R.

[0082] The rest of the preparation methods and parameters were the same as those in Example 1.

[0083] Embodiment 19 The difference between this embodiment and embodiment 1 is that in step (3), the adsorbent is placed in a muffle furnace and calcined in an air atmosphere at 200° C. for 4 h. The adsorbent is recorded as adsorbent S.

[0084] The rest of the preparation methods and parameters were the same as those in Example 1.

[0085] Embodiment 20 The difference between this embodiment and embodiment 1 is that in step (3), the adsorbent is placed in a muffle furnace and calcined at 250° C. in an air atmosphere for 4 h. The adsorbent is denoted as adsorbent T.

[0086] The rest of the preparation methods and parameters were the same as those in Example 1.

[0087] Performance Testing The adsorbents prepared in Examples 1 to 12 were analyzed and tested. The hydrogen sulfide concentration was tested using online chromatography, and when the H2S concentration detected at the outlet was 20% of the initial concentration, the adsorbent was defined to have been penetrated, and the time required for penetration was the penetration time, which was used to determine the adsorption effect of the adsorbent material.

[0088] Test process: The hydrogen sulfide adsorption effect was tested in a fixed bed quartz reactor, with an adsorbent loading of 0.5 g, an adsorbent particle size of 30-40 mesh, a reaction temperature of 80 °C, and a heating rate of 5 °C / min. The adsorbed gas was hydrogen sulfide with a concentration of 1000 ppm, the diluent gas was nitrogen, the total gas flow rate was 100 mL / min, and the reaction device temperature was maintained at 80 °C for testing.

[0089] The calculation formula of hydrogen sulfide adsorption rate is: H2S adsorption rate (%) = (1-raw gas outlet concentration / raw gas inlet concentration) × 100% The test results are shown in Table 1.

[0090] Table 1 Breakthrough time (min) Sulfur capacity (g / 100g) Example 1 52 1.46 Example 2 59 1.66 Example 3 64 1.81 Example 4 68 1.91 Example 5 54 1.54 Example 6 62 1.75 Example 7 71 2.00 Example 8 79 2.22 Example 9 60 1.66 Example 10 71 1.99 Embodiment 11 88 2.28 Example 12 96 2.36 Embodiment 13 63 1.83 Embodiment 14 76 2.15 Embodiment 15 95 2.35 Example 16 96 2.36 Embodiment 17 55 1.55 Embodiment 18 59 1.65 Embodiment 19 69 1.99 Embodiment 20 60 1.68 The regeneration process of the adsorbent is as follows: stop introducing the standard gas, adjust the H2S gas flow to air, heat the fixed bed reactor from the adsorption temperature to 260 °C through a heating furnace over 36 min, keep it at 260 °C for 60 min, then cool it down naturally to 80 °C, and then test the adsorption effect of the adsorbent again according to the test conditions.

[0091] Table 2 Breakthrough time (min) Sulfur capacity (g / 100g) Example 1 46 1.29 Example 2 53 1.51 Example 3 62 1.74 Example 4 85 2.40 Example 5 46 1.29 Example 6 55 1.56 Example 7 64 1.80 Example 8 72 2.04 Example 9 57 1.55 Example 10 60 1.69 Embodiment 11 75 2.14 Example 12 85 2.20 Embodiment 13 57 1.54 Embodiment 14 70 1.99 Embodiment 15 84 2.20 Example 16 86 2.21 Embodiment 17 46 1.29 Embodiment 18 52 1.47 Embodiment 19 61 1.68 Embodiment 20 52 1.51 analyze: As can be seen from Tables 1 and 2, the present invention provides a regenerable adsorbent for removing hydrogen sulfide at low temperature, the adsorbent includes a shaped molecular sieve and an active component loaded on the carrier, which improves the production rate of hydrogen sulfide gas in the adsorbent, and at the same time, the molecular sieve with a larger specific surface area effectively improves the utilization rate of the active component, and the adsorbent can achieve a larger sulfur capacity at low temperature, and the desulfurization accuracy can reach ppb level, and at the same time, regeneration and recycling can be achieved, which effectively reduces the industrial preparation and use costs of the adsorbent, and has a strong market practical value.

[0092] From the data results of Example 1 and Example 2-3, it can be seen that after multiple loading operations of the molecular sieve in the impregnation solution of 1 mol / L copper nitrate, the active components of the adsorbent gradually increase, and the sulfur capacity after the initial adsorption and the sulfur capacity after regeneration both show an increasing trend.

[0093] It can be seen from the data results of Example 1 and Example 2-16 that as the concentration of copper nitrate in the impregnation solution increases from 1 mol / L, 2 mol / L, 3 mol / L to 4 mol / L, the sulfur capacity of the adsorbent gradually increases, but when the impregnation Cu concentration of the adsorbent reaches a certain value, the sulfur capacity shows a stable trend, indicating that the active components that can be effectively utilized do not increase with the increase of Cu content in the adsorbent.

[0094] It can be seen from the data results of Example 1 and Examples 17-18 that when the adsorbent is impregnated, when the concentration of copper nitrate in the impregnation solution is the same, as the impregnation temperature increases during operation, the thermal motion of the active components loaded on the adsorbent increases, which increases the loading amount of the active components on the carrier, thereby increasing the adsorption effect of the adsorbent, but the increase is not large. In actual production, the heating of the impregnation solution will cause additional energy consumption.

[0095] It can be seen from the data results of Example 1 and Examples 19-20 that during the calcination process of the adsorbent, the nitrate of Cu can be completely decomposed at 170°C, and as the calcination temperature increases from 200°C and 250°C to 300°C, the active component oxide will sinter with the increase of the calcination temperature, causing the particles of the active component on the carrier surface to become larger, making the adsorption performance of the adsorbent gradually worse.

[0096] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a low-temperature gas adsorbent capable of regenerating hydrogen sulfide removal, characterized in that: The method comprises the following preparation process: First, the formed molecular sieve is mixed with a transition metal salt precursor and a solvent to carry out a loading reaction, filtration, washing, drying and calcination. The formed molecular sieve undergoes a complete operation of loading reaction, filtration, washing, drying and calcination once, which is recorded as one loading operation, and the adsorbent obtained is a primary loading adsorbent; The specific steps include: (1) dissolving a transition metal salt precursor in a solvent to obtain an impregnation solution, and impregnating the formed molecular sieve in the impregnation solution at 40-60°C for 2-4 hours. After the reaction is completed, taking out the formed molecular sieve, filtering it, and washing it for 0-5 minutes with a washing reagent at the same temperature as during the impregnation operation; (2) The washed shaped molecular sieve is dried at 120-140°C, and the dried product is calcined in an air atmosphere for 3-5 hours at a calcination temperature of 200-400°C; (3) replenishing the impregnation solution with a metal salt precursor and water (using a washing agent used to wash the formed molecular sieve) to the previous concentration, repeating the loading operation in the above steps (1)-(2), and continuously increasing the content of the active ingredient in the adsorbent to obtain the desired adsorbent; the adsorbent comprises the formed molecular sieve and the active component loaded on the carrier; the carrier is the molecular sieve, and the active component is the metal oxide; The load operation is repeated 1 to 5 times; The heating rate of the drying and calcining temperature is 5-10 ℃ / min.

2. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 1, characterized in that: The shaped molecular sieve is a commercially available cheap shaped molecular sieve, and the shape of the shaped molecular sieve includes a sphere with a size of 1.5-6 mm or a strip with a diameter of 1.5-6 mm and a length of 1.5-5 mm; preferably, the shaped shape is spherical with a size of 3-5 mm.

3. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 2, characterized in that: The shaped molecular sieve comprises a molecular sieve and a binder, wherein the molecular sieve content is 50-90% by weight and the binder content is 10-50% by weight; preferably, the molecular sieve content is 80% by weight and the binder content is 20% by weight; the molecular sieve is an A-type molecular sieve, an X-type molecular sieve, a Y-type molecular sieve, an M-type molecular sieve, or a high-silicon molecular sieve; preferably, the molecular sieve is an X-type molecular sieve.

4. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 3, characterized in that: The general chemical formula of the molecular sieve is xAl2O3∙ySiO2, y:x=0-100; preferably y:x=10-50.

5. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 1, characterized in that: The metal in the metal oxide includes one or a combination of at least two of the fourth period, fifth period or sixth period transition metals, preferably one or a combination of at least two of titanium, vanadium, manganese, iron, nickel, copper or zinc, and more preferably copper.

6. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 1, characterized in that: The transition metal salt precursor includes one or a combination of at least two of nitrate, chloride, acetate or sulfate; the solvent used includes water, ethanol, methanol, preferably water; preferably, the mixing process is accompanied by stirring, and the specific mixing method includes: (a) dissolving a transition metal precursor salt in a solvent to obtain a transition metal salt solution; (b) blending the formed molecular sieve and the impregnation solution; Preferably, the concentration of the transition metal salt solution in step (a) is 0.5 mol / L-5 mol / L, or 1-4 mol / L; The shaped molecular sieve is mixed with a solution containing a transition metal salt by impregnation, ion exchange or spraying to load the metal salt on the molecular sieve carrier, preferably by impregnation.

7. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 1, characterized in that: The immersion temperature of the carrier and the transition metal salt precursor solution is 30-90°C, preferably 40-80°C; Preferably, the volume ratio of the formed molecular sieve to the impregnation liquid is 1:(1-20), or 1:(1-10); Preferably, the impregnation reaction time is 1-5 h, or 2-4 h; The preferred washing reagent is water, ethanol, methanol, preferably water; Preferably, the number of washing operations is 0-10 times, or 0-5 times; Preferably, the single dosage of the washing agent is 1-10 times, or 1-5 times, the volume of the adsorbent; Preferably, the temperature of the washing agent is room temperature to 90°C, or room temperature to 80°C; Preferably, the drying temperature of the washed formed molecular sieve is 80-200°C, preferably 120-140°C; Preferably, the drying time of the formed molecular sieve after impregnation is 1-10 h, or 3-5 h; The calcination temperature is preferably 250-600°C, or 300-400°C; The preferred calcination time is 2-6 h, or 3-5 h; The preferred calcining atmosphere is air atmosphere; Preferably, the number of adsorbent loading operations is 1-6 times, or 1-4 times.

8. The method for preparing a regenerable low-temperature gas adsorbent for removing hydrogen sulfide according to claim 1, characterized in that: The temperature range of the low-temperature removal of hydrogen sulfide is 60-160°C.

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