A monolithic catalyst for hydrogen sulfide to sulfur and a method for preparing the same

Abstract

The application discloses a monolithic catalyst for preparing sulfur from hydrogen sulfide and a preparation method thereof. The monolithic catalyst comprises a honeycomb carrier, a coating material and an active component, and the weight ratio of the three is 100:(5-10):(0.1-1). The monolithic catalyst provided by the application is applied to a process for preparing sulfur from hydrogen sulfide, can realize complete conversion of hydrogen sulfide, has a sulfur preparation selectivity of 100%, has a low temperature for use, has good long-time running stability, and is applicable to the desulfurization field of natural gas, coal chemical industry, crude oil refining and blast furnace gas in a steel plant.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of atmospheric purification and environmental protection, and particularly relates to a monolithic catalyst for preparing sulfur from hydrogen sulfide and a preparation method thereof. BACKGROUND

[0002] Hydrogen sulfide is a pungent and toxic gas with a rotten egg smell, and is one of the pollutants of acid gases. The tail gas in the industrial production processes such as natural gas, coal chemical industry, crude oil refining and blast furnace gas in steel plants contains a large amount of hydrogen sulfide, which must be treated strictly before being discharged. At present, for high-concentration hydrogen sulfide gas, Claus process is generally used for hydrogen sulfide removal, and hydrogen sulfide is converted into elemental sulfur through two stages of thermal reaction and catalytic reaction, but due to the influence of thermodynamic equilibrium control, the conversion rate can only reach about 97%, and 0.1% of hydrogen sulfide cannot be treated. For low-concentration hydrogen sulfide, wet LO-CAT is generally used for desulfurization, and the principle is that H2S is oxidized to elemental sulfur by complex iron in an alkaline solution, but there are a series of problems such as absorption liquid treatment. In addition, there are also reports of using H2S as fuel to treat hydrogen sulfide by fuel cell, which can recover sulfur in H2S without inputting external net energy, and can convert chemical energy in the oxidation of H2S into electrical energy, but this technology also has problems such as high cost of electrolyte membrane and poor electrode performance.

[0003] The selective catalytic oxidation technology of hydrogen sulfide is not affected by thermodynamic equilibrium, and can realize the complete conversion of hydrogen sulfide. This process is often combined with Claus process to remove the remaining H2S gas. Chinese patent CN 105712301 B discloses a process for converting H2S in natural gas into sulfur, which uses natural gas containing H2S and CO2 as raw gas, and a honeycomb catalyst to convert hydrogen sulfide into sulfur. The honeycomb catalyst is composed of cordierite honeycomb carrier, carbonized coating and active component. This method can convert H2S in natural gas into sulfur by using CO2 as oxidant, but the yield of sulfur is not higher than 20%. Patents CN101380582A, CN102500362A and the like disclose catalysts and processes for selectively oxidizing H2S to elemental sulfur, and the active component of the catalyst is Fe2O3 and Cr2O3, and the carrier is a mixed oxide of TiO2 and Al2O3. The catalyst has good low-temperature activity and exhibits good catalytic activity at 160℃-240℃, but the selectivity and stability of the above-mentioned technologies for preparing sulfur from hydrogen sulfide are low. SUMMARY

[0004] In view of the problem of low selectivity and stability of hydrogen sulfide in the prior art for preparing sulfur, the application provides a monolithic catalyst for preparing sulfur from hydrogen sulfide and a preparation method thereof, and the selectivity of the catalyst for preparing sulfur from partial oxidation of hydrogen sulfide can reach 100%. The catalyst can be applied in the desulfurization field of natural gas, coal chemical industry, crude oil refining and blast furnace gas in steel plants.

[0005] The application adopts the following technical scheme:

[0006] A monolithic catalyst for preparing sulfur from hydrogen sulfide comprises a honeycomb carrier, a coating material and an active component, and the weight ratio of the three is 100:(5-10):(0.1-1).

[0007] The honeycomb carrier is made of one or more of cordierite, mullite, magnesium-aluminum spinel and foamed nickel alloy.

[0008] Preferably, the honeycomb carrier is made of magnesium-aluminum spinel, wherein the weight ratio of magnesium oxide to aluminum oxide is 1:(3-5), and the sintering temperature of the carrier is 800-1100 DEG C.

[0009] The coating material is one or more of aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, molecular sieve and activated carbon.

[0010] Preferably, the coating material is a composite oxide, wherein the weight ratio of aluminum oxide to titanium oxide to zirconium oxide is 10:(3-5):(2-5), and the calcination temperature of the oxide is 450-600 DEG C.

[0011] The active component is one or more of manganese oxide, copper oxide, cerium oxide, nickel oxide, iron oxide and cobalt oxide.

[0012] Preferably, the active component is a composite of copper oxide and manganese oxide, wherein the weight ratio of copper to manganese is 1:(10-20), the active component is loaded on the carrier by impregnation, and is calcined at 450-600 DEG C to form a shape.

[0013] A preparation method of a monolithic catalyst for preparing sulfur from hydrogen sulfide comprises the following steps:

[0014] S1, magnesium oxide and aluminum oxide are mixed according to a specified weight ratio, the mixture is made into a honeycomb shape after the carrier is prepared, and is calcined for 4-6 hours to form a honeycomb carrier;

[0015] S2, aluminum oxide, titanium oxide and zirconium oxide are weighed according to a specified weight ratio to form an oxide coating material, and the oxide coating material is coated on the honeycomb carrier and calcined for 4-6 hours to obtain a honeycomb carrier with a coating;

[0016] S3, dip the coated honeycomb carrier into a copper-manganese nitrate solution for 2-4 hours, take out and dry, and then calcine to obtain the monolithic catalyst.

[0017] The weight ratio of the magnesium oxide and the aluminum oxide added in step S1 is 1:(3-5), and the sintering temperature of the carrier is 800-1100 DEG C.

[0018] The weight ratio of the aluminum oxide, the titanium oxide and the zirconium oxide added in step S2 is 10:(3-5):(2-5), and the calcination temperature of the oxides is 450-600 DEG C.

[0019] The weight ratio of copper and manganese in the copper-manganese nitrate solution added in step S2 is 1:(10-20), the active component is loaded onto the carrier by impregnation, and then calcined at 450-600 DEG C to form.

[0020] Application of a monolithic catalyst in the preparation of sulfur from hydrogen sulfide.

[0021] The technical scheme of the present application has the following advantages:

[0022] A. The monolithic catalyst provided by the present application can completely convert hydrogen sulfide, and the selectivity of the preparation of sulfur is 100%, and the catalyst has good stability in long-term operation.

[0023] B. The monolithic catalyst provided by the present application is used at a relatively low temperature, and for different hydrogen sulfide concentrations (0.01%-5%), the reaction temperature is between 150 DEG C and 230 DEG C, and the volume space velocity is between 100 and 10000 h -1 , and the hydrogen sulfide can be completely converted. In particular, in a high-concentration carbon monoxide atmosphere (such as a blast furnace gas atmosphere for desulfurization), the selectivity of the monolithic catalyst provided by the present application for the preparation of sulfur from hydrogen sulfide is still 100%.

[0024] C. The monolithic catalyst provided by the present application has a selectivity of 100% for the preparation of sulfur from hydrogen sulfide in an atmosphere containing hydrogen sulfide: oxygen with a volume ratio of 1:(0.5-5) (i.e. when oxygen is excessive), and no sulfur dioxide is produced in the partial oxidation reaction of hydrogen sulfide below 250 DEG C. DETAILED DESCRIPTION

[0025] The technical scheme of the present application will be described below. Obviously, the described embodiments are part of the embodiments of the present application, but not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] Example 1:

[0027] The weight ratio of magnesium oxide to alumina is 1:3, the honeycomb carrier is made by carrier and is baked at 800°C for 4 hours to form the honeycomb carrier; the coating material with the weight ratio of alumina to titanium oxide to zirconium oxide being 10:3:2 is coated on the honeycomb carrier, and then is baked at 450°C for 4 hours; finally, the carrier is immersed in the copper manganese nitrate solution containing copper and manganese with the weight ratio of 1:10 for 2 hours, is taken out and dried, and is baked at 450°C to form the monolithic catalyst. The weight ratio of the honeycomb carrier to the coating material to the active component in the final monolithic catalyst is 100:5:0.2.

[0028] The activity test is conducted on the catalyst, and the reaction gas components are as follows: the content of hydrogen sulfide is 0.5%, the content of oxygen is 1%, the content of carbon dioxide is 10%, the content of carbon monoxide is 20%, and the other is nitrogen. When the reaction temperature is 200°C and the volume space velocity is 1000h -1 The complete conversion of hydrogen sulfide can be realized, the selectivity to sulfur is 100%, and the catalyst performance does not change after the reaction for 240 hours.

[0029] Example 2:

[0030] The weight ratio of magnesium oxide to alumina is 1:4, the honeycomb carrier is made by carrier and is baked at 900°C for 4 hours to form the honeycomb carrier. The coating material with the weight ratio of alumina to titanium oxide to zirconium oxide being 10:3:3 is coated on the honeycomb carrier, and then is baked at 550°C for 4 hours. Finally, the carrier is immersed in the copper manganese nitrate solution containing copper and manganese with the weight ratio of 1:13 for 2 hours, is taken out and dried, and is baked at 500°C to form the monolithic catalyst. The weight ratio of the honeycomb carrier to the coating material to the active component in the final monolithic catalyst is 100:6:0.5.

[0031] The activity test is conducted on the catalyst, and the reaction gas components are as follows: the content of hydrogen sulfide is 0.05%, the content of oxygen is 0.2%, the content of carbon dioxide is 10%, the content of carbon monoxide is 20%, and the other is nitrogen. When the reaction temperature is 180°C and the volume space velocity is 8000h -1 The complete conversion of hydrogen sulfide can be realized, the selectivity to sulfur is 100%, and the catalyst performance does not change after the reaction for 720 hours.

[0032] Example 3:

[0033] Magnesium oxide and aluminum oxide were mixed in a weight ratio of 1:5, formed into a honeycomb structure on a carrier, and then calcined at 1100℃ for 4 hours to form a honeycomb carrier. A coating material with an aluminum oxide:titanium oxide:zirconia weight ratio of 10:4:3 was applied to the honeycomb carrier, followed by calcination at 600℃ for 4 hours. Finally, the carrier was immersed in a copper-manganese nitrate solution containing copper and manganese in a weight ratio of 1:15 for 2 hours, dried, and then calcined at 500℃ to form a monolithic catalyst. The final monolithic catalyst had a honeycomb carrier:coating material:active component weight ratio of 100:7:0.8.

[0034] The catalyst activity was tested in an atmosphere containing 0.02% hydrogen sulfide, 0.1% oxygen, 2% carbon dioxide, and the remainder methane. The reaction temperature was 170℃, and the volume hourly space velocity (VHSV) was 1000 h⁻¹. -1 It can achieve complete conversion of hydrogen sulfide with 100% selectivity for sulfur, and the catalyst performance remains unchanged after 1440 hours of reaction.

[0035] Example 4:

[0036] A magnesium oxide to aluminum oxide weight ratio of 1:4.5 was used to form a honeycomb structure on a carrier, which was then calcined at 1050℃ for 4 hours to form a honeycomb carrier. A coating material with an aluminum oxide:titanium oxide:zirconia weight ratio of 10:5:5 was applied to the honeycomb carrier, followed by calcination at 500℃ for 4 hours. Finally, the carrier was immersed in a copper-manganese nitrate solution containing copper and manganese at a weight ratio of 1:20 for 2 hours, dried, and then calcined at 600℃ to form a monolithic catalyst. The final monolithic catalyst had a honeycomb carrier:coating material:active component weight ratio of 100:8:0.7.

[0037] The catalyst was tested for activity in an atmosphere containing 2% hydrogen sulfide, 1.5% oxygen, 8% carbon dioxide, 1% carbon monoxide, and the remainder nitrogen. The volume hourly space velocity (VHSV) was 2000 h⁻¹ at a reaction temperature of 220°C. -1 It can achieve complete conversion of hydrogen sulfide and has 100% selectivity for sulfur. The catalyst performance remains unchanged after 120 hours of reaction.

[0038] Comparison Example 1:

[0039] A coating material with a weight ratio of alumina to titania of 10:7 was coated onto a cordierite honeycomb support and then calcined at 500°C for 4 hours. The support was then impregnated with a solution of copper and iron nitrates having a weight ratio of copper to iron of 1:10 for 2 hours, removed and dried, and then calcined at 500°C to form a monolithic catalyst. The final weight ratio of honeycomb support:coating material:active components was 100:10:0.5. The catalyst was tested for activity in a reaction gas having a composition of 1.0% hydrogen sulfide, 1.0% oxygen, 8% carbon dioxide, 10% carbon monoxide, and the balance nitrogen. At a reaction temperature of 220°C and a volumetric space velocity of 1000 h -1 The conversion of hydrogen sulfide was only 82% and the selectivity to sulfur was 91% with a selectivity to sulfur dioxide of 9%. After 48 hours of reaction, the conversion of hydrogen sulfide decreased to 65% and the selectivity to sulfur decreased to 71%.

[0040] Comparative Example 2

[0041] A spherical silica support was impregnated with a solution of copper and iron nitrates having a weight ratio of copper to iron of 1:10 for 2 hours, removed and dried, and then calcined at 500°C to form a catalyst. The final weight ratio of active components was 5%. The catalyst was tested for activity in a reaction gas having a composition of 1% hydrogen sulfide, 1.0% oxygen, 8% carbon dioxide, 20% carbon monoxide, and the balance nitrogen. At a reaction temperature of 230°C and a volumetric space velocity of 800 h -1 The conversion of hydrogen sulfide was 92% and the selectivity to sulfur was 75% with a selectivity to sulfur dioxide of 11% and a selectivity to carbonyl sulfide of 8%. The remaining sulfur species were accumulated on the catalyst as sulfate. After 48 hours of reaction, the conversion of hydrogen sulfide decreased to 76% and the selectivity to sulfur decreased to 70%.

[0042] In summary, the monolithic catalyst of the present application can achieve complete conversion of hydrogen sulfide and a selectivity of 100% to sulfur. The catalyst has good stability over a long period of time. The catalyst can be used at a low temperature of 150-230°C and a volumetric space velocity of 100-10000 h -1 The monolithic catalyst of the present application can achieve complete conversion of hydrogen sulfide. In particular, in a high carbon monoxide atmosphere (e.g., a blast furnace gas atmosphere), the selectivity of the monolithic catalyst of the present application to sulfur from hydrogen sulfide is still 100%. The selectivity of the catalyst to sulfur from hydrogen sulfide is still 100% when oxygen is in excess and no sulfur dioxide is produced from the partial oxidation of hydrogen sulfide at a temperature of 250°C or below.

[0043] Obviously, the above-described embodiments are merely exemplary but not limiting of the present application. It is intended to cover any and all modifications and variations of the present application along with its equivalents. It is intended that the present application encompass such modifications and variations as fall within the scope of the appended claims.

Claims

1. A monolithic catalyst for the production of sulfur from hydrogen sulfide, characterized in that: The product comprises a honeycomb carrier, a coating material, and an active component, with a weight ratio of 100:(5-10):(0.1-1). The honeycomb carrier is made of magnesium aluminum spinel, wherein the weight ratio of magnesium oxide to aluminum oxide is 1:(3-5), and the sintering temperature of the carrier is 800-1100℃. The active component is a composite of copper oxide and manganese oxide, wherein the weight ratio of copper to manganese is 1:(10-20). The active component is loaded onto the carrier by impregnation and then sintered at 450-600℃. The coating material is a composite oxide, wherein the weight ratio of aluminum oxide:titanium oxide:zirconia is 10:(3~5):(2~5), and the calcination temperature of the oxide is 450~600℃; The preparation method of the monolithic catalyst for hydrogen sulfide to sulfur production includes the following steps: S1. Weigh magnesium oxide and aluminum oxide according to the specified weight ratio, mix them, and then make them into a honeycomb structure through a carrier. After calcination for 4 to 6 hours, a honeycomb carrier is formed. S2. Weigh alumina, titanium oxide and zirconium oxide according to the specified weight ratio to form an oxide coating material, coat it onto the honeycomb carrier, and calcine for 4 to 6 hours to obtain a coated honeycomb carrier. S3. The coated honeycomb carrier is immersed in a copper-manganese nitrate solution for 2-4 hours, then removed, dried, and calcined to obtain the monolithic catalyst.

2. A method for preparing a monolithic catalyst for hydrogen sulfide-to-sulfur production as described in claim 1, characterized in that, Includes the following steps: S1. Weigh magnesium oxide and aluminum oxide according to the specified weight ratio, mix them, and then make them into a honeycomb structure through a carrier. After calcination for 4 to 6 hours, a honeycomb carrier is formed. S2. Weigh alumina, titanium oxide and zirconium oxide according to the specified weight ratio to form an oxide coating material, coat it onto the honeycomb carrier, and calcine for 4 to 6 hours to obtain a coated honeycomb carrier. S3. The coated honeycomb carrier is immersed in a copper-manganese nitrate solution for 2-4 hours, then removed, dried, and calcined to obtain the monolithic catalyst.

3. The application of the monolithic catalyst according to claim 1 in the production of sulfur from hydrogen sulfide.