CN107175108A - A kind of cobalt series catalyst that sulphur processed is reduced for sulfur dioxide in flue gas and its production and use - Google Patents

Abstract

The present invention provides a Co _- based catalyst for sulfur production from SO2 reduction in flue gas and its preparation method and application. The catalyst includes a carrier and an active component and an auxiliary agent coated on the carrier, wherein the active component It is an oxide of Co, and the auxiliary agent is any one of Cu, Ni, La, Mg, Ca or Ba or a combination of at least two oxides. The preparation method is as follows: the active components and auxiliary agents are loaded on the carrier by an equal-volume impregnation method, and then dried, calcined and vulcanized to prepare the Co-based catalyst. The neutral component of the Co-based catalyst described in the present invention is uniformly dispersed, has stable performance and uniform particle size, and is suitable for catalyzing SO2 reduction in flue gas to produce sulfur in a fixed _- bed reactor.

Description

A kind of cobalt-based catalyst for reducing sulfur dioxide in flue gas and preparation method thereof law and use

technical field

The invention belongs to the field of flue gas treatment, and relates to a Co _- based catalyst used for reducing SO2 in flue gas to produce sulfur and its treatment method and application, especially to a kind of catalyst with uniform dispersion of active components, stable performance, good mechanical strength and particle size A uniform Co-based catalyst suitable for producing elemental sulfur from flue gas SO ₂ and its preparation method and application.

Background technique

Pyrometallurgy is a process of extracting and refining metals or their compounds from ores at high temperatures using fuel, electric energy or other energy sources to generate high temperatures. Pyrometallurgy is generally divided into steps such as ore preparation, smelting, refining and flue gas treatment. It is the oldest and most widely used metal smelting method in modern times. Sulfur, which exists in the form of elemental sulfur, occupies a pivotal position in the production of the national economy. Sulfur has become the main raw material for production in industries such as dyestuffs, rubber, papermaking, and military industry. Need to spend a huge amount of foreign exchange to import sulfur. In the face of such a situation, we cannot deny that only by changing harmful sulfur into beneficial sulfur (for example, if SO ₂ in flue gas is changed into available resource sulfur) will completely solve the problem of China's utilization of sulfur resources. Therefore, the selective reduction of SO ₂ in the flue gas to elemental sulfur will be a flue gas desulfurization method with broad market prospects, both economic and social benefits, and suitable for China's national conditions.

At present, many experts and scholars at home and abroad have also made great efforts in the basic and technical research of desulfurization, and believe that the best way to deal with high-concentration SO ₂ is to selectively reduce SO ₂ to elemental S. There are two main technologies for producing sulfur from sulfur dioxide flue gas: direct reduction method and indirect reduction method. The direct reduction method can be divided into H ₂ reduction method, carbon reduction method, hydrocarbon (mainly CH ₄ ) reduction method, CO reduction method and NH ₃ reduction method according to the different reducing agents used. And other methods are also difficult to realize industrialization due to various reasons. There are hydrogen reduction method and high-temperature methane reduction method that have been industrialized, but the transportation and storage of _H2 sources are not convenient and the operability is poor, and the consumption of natural gas and oxygen in the high-temperature methane reduction process is huge.

At present, the traditional preparation methods of sulfur dioxide reduction catalysts include sol-gel method and impregnation method. The sol-gel method is that the active components are doped on the colloid, and they are dried and roasted together. In this method, the distribution of the active components in the catalyst is uniform. For example, Rao Yuxiang and others doped some Co, Mo and Ni mixed roasting in the process of perovskite preparation, and the prepared catalyst was used to catalyze the process of methane reduction of sulfur dioxide, and achieved good results, but the catalytic temperature in this method is relatively high. The process consumes too much energy ("Research on Methane Desulfurization by Perovskite-type Composite Oxide Catalyst", Rao Yuxiang et al., "Petrochemical Industry", Volume 33 in 2004).

The most widely used preparation method of sulfur dioxide reduction catalyst is the impregnation method, because the preparation process of the impregnation method is simple, and the concentration of active components on the surface of the catalyst is relatively high, and the concentration gradually decreases from the outside to the inside, which meets the requirements of the process and large-scale production. In the impregnation method, the carrier used usually chooses some basic oxides or amphoteric oxides, the purpose of which is to adsorb sulfur dioxide on the surface of the catalyst and promote the catalytic process. For example, Moody of Los Alamos National Laboratory used Ru/Al ₂ O ₃ with the best catalytic performance as a catalyst for research. When the reaction temperature was 156 ° C, the conversion rate of the catalyst was over 90%, and there were basically no by-products. H ₂ S, but the cost of using precious metals is too high. Boswell et al. used Fe-based metals (Fe, Co, Ni) loaded on porous materials such as asbestos, diatomaceous earth, and porous bricks as catalysts to investigate the reaction of H ₂ reducing SO ₂ . Wang Shizhong et al. used rare earth metal (Nb, Ce, Pr, La, Sm) oxides supported on Al ₂ O ₃ to study the catalytic process of CO reduction to SO ₂ , and found that rare earth oxides have a good desulfurization effect, Pr/ A1 ₂ O ₃ is best. In addition, CeO ₂ is also a good carrier for reduction and desulfurization. Liu's research shows that the yield of elemental sulfur of Ni/CeO ₂ and Cu/CeO ₂ at 500°C is above 95%. Mulligan et al. used pure crystal MoS ₂ , WS, FeS and supported MoS ₂ /A1 ₂ O ₃ to study and found that MoS had higher selectivity than WS and FeS catalysts, and supported MoS ₂ /A12O ₃ was more active than A1 ₂ O ₃ Higher, but the preparation method is quite complicated, not suitable for large-scale production.

In short, some of the catalysts in the prior art are relatively expensive to prepare, some have complicated preparation methods, and some have poor activity. In view of economy and industrial application, it is necessary to develop a catalyst with low cost, simple preparation process, and high activity. is inevitable.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a Co _- based catalyst for reducing SO2 in flue gas to produce sulfur, as well as its preparation method and application. In the present invention, through the metal oxide of the active component Co loaded on the carrier, and through its synergistic effect with the auxiliary agent, the catalyst can be used for _SO2 Reduction of sulfur production has higher activity, and higher In addition, the neutral components of the Co-based catalyst are uniformly dispersed, stable in performance and uniform in particle size, and are suitable for catalyzing SO2 in flue gas to produce sulfur in a fixed _- bed reactor.

For reaching this purpose, the present invention adopts following technical scheme:

One of the purposes of the present invention is to provide a Co _- based catalyst for SO in flue gas Reduction of sulfur, the catalyst includes a carrier and an active component and an auxiliary agent coated on the carrier, wherein the active component is Co oxides, and the auxiliary agent is any one of Cu, Ni, La, Mg, Ca or Ba or a combination of at least two oxides.

Wherein, the additive can be a combination of Cu and Ni, a combination of La and Mg, a combination of Ca and Ba, a combination of Cu, Ni and La, a combination of La, Mg and Ca, a combination of Mg, Ca and Ba, Cu , a combination of Ni, La, Mg and Ca, etc.

The following are preferred technical solutions of the present invention, but not as limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

As a preferred technical solution of the present invention, the carrier is any one or a combination of at least two of γ-Al ₂ O ₃ , SiO ₂ , TiO ₂ or ZSM-5.

Preferably, the carrier is particles with uniform shape, preferably spherical particles and/or powder.

In the present invention, the carrier is not limited to the forms listed above, and other uniform particles with special shapes that can achieve the same effect are applicable to the present invention.

As a preferred technical solution of the present invention, the loading of Co in the active component of the catalyst is 3wt% to 16wt%, such as 3wt%, 5wt%, 7wt%, 10wt%, 13wt%, 15wt% or 16wt%, etc., However, it is not limited to the listed values, and other unlisted values within the range of values are also applicable.

In the present invention, the loading of Co needs to be controlled within a certain range. If the loading of Co is too much, the specific surface area of the catalyst will be reduced rapidly; if the loading of Co is too low, the concentration of the active center of the catalyst will be reduced, and then affect the catalytic performance of the catalyst.

Preferably, the loading amount of Cu in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, Other unrecited values within this value range are also applicable.

Preferably, the loading amount of Ni in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, Other unrecited values within this value range are also applicable.

Preferably, the loading amount of La in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, etc., but not limited to the listed values, Other unrecited values within this value range are also applicable.

Preferably, the loading amount of Mg in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, the Other unrecited values within the range of values also apply.

Preferably, the loading amount of Ca in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, the Other unrecited values within the range of values also apply.

Preferably, the loading of Ba in the promoter in the catalyst is 1wt% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, Other unrecited values within this value range are also applicable.

The second object of the present invention is to provide a preparation method of the above-mentioned Co-based catalyst. The preparation method is as follows: the active component and the auxiliary agent are loaded on the carrier by an equal-volume impregnation method, and dried, roasted and vulcanized to obtain Co catalysts.

As a preferred technical solution of the present invention, the preparation method specifically includes the following steps:

(1) Cobalt source and additive metal salt are mixed to make solution;

(2) adding a carrier to the solution described in step (1), impregnating with equal volume to obtain the impregnated carrier;

(3) The impregnated carrier described in step (2) is dried and calcined to obtain a catalyst precursor;

(4) Sulphurizing the catalyst precursor described in step (3) to obtain a Co-based catalyst.

In the present invention, the activity and sulfur resistance of the catalyst can be greatly improved by sulfurizing the catalyst precursor.

As a preferred technical solution of the present invention, the cobalt source in step (1) is cobalt nitrate.

Preferably, the promoter metal salt in step (1) is any one or a combination of at least two of nickel nitrate, copper nitrate, lanthanum nitrate, magnesium nitrate, calcium nitrate or barium nitrate, the combination is typical but not limiting Examples are: the combination of nickel nitrate and copper nitrate, the combination of lanthanum nitrate and magnesium nitrate, the combination of calcium nitrate and barium nitrate, the combination of nickel nitrate, copper nitrate, lanthanum nitrate and magnesium nitrate, the combination of lanthanum nitrate, magnesium nitrate, calcium nitrate and Combinations of barium nitrate, etc.

Preferably, the amount of cobalt source described in step (1) is: make the loading of Co in the active component in the catalyst after loading be 3wt%～16wt%, such as 3wt%, 5wt%, 7wt%, 10wt%, 13wt% %, 15wt% or 16wt%, etc., but not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the amount of the promoter metal salt in the solution described in step (1) is: the loading amount of Cu in the supported catalyst is 1% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% % or 6wt%, etc., but not limited to the listed values, other unlisted values within this range are also applicable; Ni loading is 1% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt% , 5wt% or 6wt%, etc., but not limited to the listed values, other unlisted values within the range of values are also applicable; the loading of La is 1% to 6wt%, such as 1wt%, 2wt%, 3wt%, 4wt%, 5wt% or 6wt%, but not limited to the listed values, other unlisted values within this range are also applicable; Mg loading is 1% to 6wt%, such as 1wt%, 2wt%, 3wt% , 4wt%, 5wt% or 6wt%, etc., but not limited to the listed values, other unlisted values within the range of values are also applicable; the loading of Ca is 1% to 6wt%, such as 1wt%, 2wt%, 3wt% %, 4wt%, 5wt% or 6wt%, but not limited to the listed values, other unlisted values within the range of values are also applicable; the loading of Ba is 1% to 6wt%, such as 1wt%, 2wt% , 3wt%, 4wt%, 5wt% or 6wt%, etc., but not limited to the listed values, other unlisted values within the range of values are also applicable.

Here, it is not limited that the loaded additives include Cu, Ni, La, Mg, Ca and Ba, but can be any one or at least two of them, as long as the loaded concentration satisfies the above range.

Preferably, the solvent in the solution described in step (1) is water.

As a preferred technical solution of the present invention, the carrier in step (2) is any one or a combination of at least two of γ-Al ₂ O ₃ , SiO ₂ , TiO ₂ or ZSM-5.

Preferably, the time for equal-volume immersion in step (2) is 1h to 6h, such as 1h, 2h, 3h, 4h, 5h or 6h, etc., but not limited to the listed values, other unlisted values within the range Numerical values also apply.

Preferably, the drying temperature in step (3) is 100°C to 130°C, such as 100°C, 105°C, 110°C, 115°C, 120°C, 125°C or 130°C, etc., but not limited to the listed values, Other unrecited values within this value range are also applicable.

Preferably, the drying time in step (3) is 1h to 6h, such as 1h, 2h, 3h, 4h, 5h or 6h, etc., but it is not limited to the listed values, and other unlisted values within this range are also applicable .

Preferably, the roasting temperature in step (3) is 400°C to 600°C, such as 400°C, 430°C, 450°C, 470°C, 500°C, 530°C, 550°C, 570°C or 600°C, etc., but not Not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the roasting time in step (3) is 6h to 12h, such as 6h, 8h, 10h or 12h, etc., but it is not limited to the listed values, and other unlisted values within this range are also applicable.

Preferably, the calcination in step (3) is carried out in a muffle furnace.

As a preferred technical solution of the present invention, the vulcanization in step (4) is carried out under a mixed atmosphere of H ₂ S and H ₂ .

Preferably, the volume content of H _{2 S in the mixed atmosphere of H 2 S} and H ₂ is 5%-15%, such as 5%, 7%, 10%, 13% or 15%, but not limited to the Numerical values listed, other unlisted numerical values within the numerical range are also applicable.

Preferably, the vulcanization temperature in step (4) is 400°C to 600°C, such as 400°C, 430°C, 450°C, 470°C, 500°C, 530°C, 550°C, 570°C or 600°C, etc., but not Not limited to the listed values, other unlisted values within the range of values are also applicable.

Preferably, the vulcanization time in step (4) is 0.5h to 6h, such as 0.5h, 1h, 2h, 3h, 4h, 5h or 6h, etc., but it is not limited to the listed values. The listed values also apply.

Preferably, the vulcanization in step (4) is carried out in a tube furnace.

The third object of the present invention is to provide the use of the above-mentioned Co-based catalyst, that is, to use the Co _- based catalyst to catalyze the reduction of SO2 in flue gas in a fixed-bed reactor to prepare elemental sulfur.

Preferably, the SO2 content in the flue gas is ₂₀ % to 30%, such as 20%, 22%, 24%, 26%, 28% or 30%, but not limited to the listed values, the values Other unrecited values within the range also apply.

As a preferred technical solution of the present invention, the method for preparing elemental sulfur by reducing SO2 in the catalytic flue gas is _:

The Co-based catalyst is loaded in a fixed-bed reactor, and after the air in the system is discharged, the flue gas and coal gas are preheated to 300°C-450°C, and then enter the fixed-bed reactor to react at 350°C-450°C , to reduce SO2 in the flue gas to produce _elemental sulfur.

That is to say, after the sulfurized catalyst is sampled and crushed, catalyst particles with a reasonable particle size are screened out, and put into a fixed bed micro-reaction evaluation device for effect evaluation. After sulfur crystallization and dehydration treatment, the tail gas is analyzed to calculate the conversion rate and selective.

Compared with the prior art, the present invention has the following beneficial effects:

In the present invention, through the metal oxide of the active component Co loaded on the carrier, and through its synergistic effect with the auxiliary agent, the catalyst can be used for _SO2 Reduction of sulfur production has higher activity, and higher selectivity; and, the neutral components of the Co-based catalyst are uniformly dispersed, stable in performance and uniform in particle size, and are applicable to catalyzing SO in the flue gas in a fixed _- bed reactor to reduce sulfur, so that the conversion rate of _SO can be More than 90%, the selectivity can reach more than 90%.

At the same time, the catalyst of the present invention can be regenerated after being deactivated, only needs secondary roasting and sulfidation in situ, and the activity of the catalyst can be restored, thereby improving the resource recycling rate.

Description of drawings

Fig. 1 is the schematic diagram of the effect evaluation device of Co series catalyst described in the present invention;

Among them, 1-preheater, 2-fixed bed reactor, 3-sulfur crystallization tank, 4-water removal tank, 5-drying pipe, 6-tail gas detection, 7-tail gas purification.

detailed description

In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention will be further described in detail below. However, the following embodiments are only simple examples of the present invention, and do not represent or limit the protection scope of the present invention, and the protection scope of the present invention shall be determined by the claims.

Part of the specific examples of the present invention provides a Co _- based catalyst for sulfur production from SO in flue gas and a preparation method thereof. The catalyst includes a carrier and an active component and an auxiliary agent coated on the carrier, wherein the active The component is an oxide of Co, and the additive is any one of Cu, Ni, La, Mg, Ca or Ba or a combination of at least two oxides.

The preparation method is as follows: the active components and auxiliary agents are loaded on the carrier by an equal-volume impregnation method, and then dried, calcined and vulcanized to prepare the Co-based catalyst.

Catalytic effect evaluation is carried out to described Co series catalyst, and its device is as shown in Figure 1, described Co series catalyst is packed in the fixed-bed reactor 2, removes the air in the system with nitrogen earlier, then preheater 1 temperature rises to 300-450°C, the fixed-bed reactor 2 is heated to 350-450°C, when the temperature is stable, the flue gas (reaction gas) and coal gas (reducing gas) are introduced in proportion, and pass through the fixed-bed reactor 2 and the sulfur crystallization tank 3 and after the water removal tank ₄ , quantitatively analyze the tail gas to calculate the SO2 conversion rate and selectivity.

The following are typical but non-limiting embodiments of the present invention:

Example 1:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

(2) Calculate the amount of Co(NO ₃ ) ₂ 6H ₂ O needed to prepare 14wt% Co/γ-Al ₂ O ₃ catalyst (carrier is 15g) according to the mass of carrier, wherein 14% is the mass of metal oxide and Ratio of vector mass. Dissolve 8.16g of Co(NO ₃ ) ₂ ·6H ₂ O in 15.3mL of deionized water, stir until completely dissolved to form a Co(NO ₃ ) ₂ solution with the desired concentration; then pour the solution into the Weigh 15g of γ-Al ₂ O ₃ carrier into a small beaker, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h.

(3) Put the above catalyst in an oven at 110°C to dry for 6 hours, then place it in a muffle furnace and roast it at 500°C for 12 hours. After cooling, a γ-Al ₂ O ₃ Catalyst precursor;

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 400°C for 1 hour, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co/γ-Al ₂ O ₃ catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 93.2%, and the selectivity is 90.5%.

Example 2:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

(2) Calculate the required Co(NO ₃ ) ₂ ·6H ₂ O and Cu(NO ₃ ) ₂ ·3H for the preparation of 14%Co-4%Cu/γ-Al ₂ O ₃ catalyst (15g support) according to the weight of the carrier The amount of ₂ O. Dissolve 8.16g of Co(NO ₃ ) ₂ ·6H ₂ O and 1.82g of Cu(NO ₃ ) ₂ ·3H ₂ O in 15.3mL of deionized water, stir until completely dissolved to form an impregnation solution with the required concentration ; Then pour the solution into a small beaker that has weighed 15g of γ-Al ₂ O ₃ carrier at one time, and keep stirring, the carrier is just completely impregnated, and stand for 0.5h.

(3) Put the above catalyst in an oven at 110°C to dry for 6 hours, then put it in a muffle furnace and heat it up to 500°C for 12 hours, and after cooling, obtain a γ-Al ₂ O catalyst with uniform distribution of Co and Cu oxides. ₃ catalyst precursors;

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 400°C for 1 hour, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co-4% Cu/γ-Al ₂ O ₃ catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 94.0% and the selectivity is 96.1%.

Example 3:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

( ₂ ) Calculate the Co(NO ₃ ) ₂ ·6H ₂ O, Cu ₍ NO ₃ ) ₂ ·3H ₂ O and the amount of La(NO ₃ ) ₃ ·6H ₂ O. Dissolve 8.16 g of Co(NO ₃ ) ₂ ·6H ₂ O, 1.82 g of Cu(NO ₃ ) ₂ ·3H ₂ O and 0.9352 g of La(NO ₃ ) ₃ ·6H ₂ O in 15.3 mL of deionized In water, stir until it is completely dissolved to form an impregnation solution of the required concentration. Then pour the solution into a small beaker that has weighed 15g of γ-Al ₂ O ₃ carrier at one time, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h;

(3) Put the above-mentioned catalyst in an oven at 100°C for 5 hours, then place it in a muffle furnace and heat it up to 450°C for 10 hours. After cooling, the γ-Al Catalyst precursor for _{2O3 ;}

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 500°C for 4 hours, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co-4%Cu- ₂ %La/γ- _Al2O3 catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 93.8%, and the selectivity is 96.5%.

Example 4:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

(2) Calculate the required Co(NO ₃ ) ₂ ·6H ₂ O and Cu(NO ₃ ) ₂ ·3H for the preparation of 14%Co-4%Cu/γ-Al ₂ O ₃ catalyst (15g support) according to the weight of the carrier The amount of ₂ O. Dissolve 8.16g of Co(NO ₃ ) ₂ ·6H ₂ O and 1.82g of Cu(NO ₃ ) ₂ ·3H ₂ O in 15.3mL of deionized water, stir until completely dissolved to form an impregnation solution with the required concentration . Then pour the solution into a small beaker that has weighed 15g of γ-Al ₂ O ₃ carrier at one time, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h;

(3) Put the above catalyst in an oven at 130°C to dry for 2 hours, then place it in a muffle furnace to program the temperature to 550°C and bake it for 7 hours. After cooling, a γ-Al ₂ O ₃ catalyst precursors;

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 600°C for 2 hours, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co-4% Cu/γ-Al ₂ O ₃ catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 86.5%, and the selectivity is 93.4%.

Example 5:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

(2) Calculate the required Co(NO ₃ ) ₂ ·6H ₂ O and Cu(NO ₃ ) ₂ ·3H for the preparation of 14%Co-6%Cu/γ-Al ₂ O ₃ catalyst (15g support) according to the weight of the carrier The amount of ₂ O. Dissolve 8.16g of Co(NO ₃ ) ₂ ·6H ₂ O and 2.73g of Cu(NO ₃ ) ₂ ·3H ₂ O in 15.3mL of deionized water, stir until completely dissolved to form an impregnation solution with the required concentration . Then pour the solution into a small beaker that has weighed 15g of γ-Al ₂ O ₃ carrier at one time, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h;

(3) Put the above catalyst in an oven at 110°C to dry for 6 hours, then put it in a muffle furnace and heat it up to 500°C for 12 hours, and after cooling, obtain a γ-Al ₂ O catalyst with uniform distribution of Co and Cu oxides. ₃ catalyst precursors;

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 400°C for 1 hour, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co-6% Cu/γ-Al ₂ O ₃ catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 92.5%, and the selectivity is 94.3%.

Embodiment 6:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of _SiO2 particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping when the water is just fully impregnated with _SiO2 , weigh and calculate the amount of water added, and determine the amount of 15g Carrier SiO ₂ absorbs 16.5g of water;

(2) Calculate the amount of Co(NO ₃ ) ₂ ·6H ₂ O needed to prepare the 14% Co/SiO ₂ catalyst (with a support of 15 g) based on the mass of the support. Dissolve 8.16g of Co(NO ₃ ) ₂ ·6H ₂ O in 16.5mL of deionized water, and stir until completely dissolved to form an impregnation solution with the desired concentration. Then pour the solution into a small beaker that has weighed 15g of SiO ₂ carrier at one time, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h;

(3) Put the above-mentioned catalyst into an oven at 110° C. to dry for 6 hours, then place it in a muffle furnace and heat it up to 500° C. and roast it for ₁₂ hours. After cooling, obtain a catalyst precursor in SiO in which the oxides of Co are uniformly distributed;

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 400°C for 1 hour, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co/ _SiO2 catalyst.

Accurately weigh 1g of the catalyst and put it into a micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 60.4%, and the selectivity is 74.6%.

Embodiment 7:

This embodiment provides a Co _- based catalyst and a preparation method thereof for SO reduction in flue gas to produce sulfur, the method comprising the following steps:

(1) Weigh 15g of γ-Al ₂ O ₃ particles with a fixed mesh number, put them into a small beaker, gradually drop in deionized water, stop dripping water when the water is just fully impregnated with γ-Al ₂ O ₃ , weigh and calculate The amount of water added is determined to be 15.3g of water absorbed by 15g of carrier γ-Al ₂ O ₃ ;

(2) Calculate the required Co(NO ₃ ) ₂ ·6H ₂ for the preparation of 14%Co+4%Cu+4%Ni/γ-Al ₂ O ₃ catalyst (15g carrier) based on the mass of carrier O, Cu(NO ₃ ) ₂ ·3H ₂ O and Ni(NO ₃ ) ₂ ·6H ₂ O, amount. Dissolve 8.16 g of Co(NO ₃ ) ₂ 6H ₂ O, 1.82 g of Cu(NO ₃ ) ₂ 3H ₂ O and 2.34 g of Ni(NO ₃ ) ₂ 6H ₂ O in 15.3 mL of deionized water , and stir until completely dissolved to form a mixed solution of the desired concentration. Then pour the solution into a small beaker that has weighed 15g of γ-Al ₂ O ₃ carrier at one time, and keep stirring, the carrier is just completely impregnated, and place it for 0.5h;

(3) Put the above-mentioned catalyst in an oven at 110°C for 6 hours, then place it in a muffle furnace and heat it up to 500°C for 12 hours. Catalyst precursor for _{2O3 ;}

(4) Put the catalyst precursor into a tube furnace, pre-sulfurize it in a 10% H ₂ S/H ₂ atmosphere at 400°C for 1 hour, and then lower it to room temperature to obtain a 14% catalyst with uniform particle size and uniform distribution of active components. Co+4%Cu+4%Ni/γ _{- Al2O3} catalyst.

Accurately weigh 1g of the catalyst and put it into the micro _- reactor evaluation device for evaluation. After the exhaust gas test, it is calculated that the SO2 conversion rate is 91.6%, and the selectivity is 92.5%.

Embodiment 8:

This example provides an evaluation method for the Co-based catalyst. Accurately weigh 1 g of the presulfided 14% Co-4% Cu-2% La/γ-Al ₂ O ₃ catalyst and fill it into a fixed-bed reactor in the evaluation. The reaction temperature is 400°C, the reaction space velocity is 5000h ^-1 , the proportion of SO ₂ in the simulated metallurgical flue gas is 9.65%, and the total amount of CO and H ₂ in the reducing gas is twice that of SO ₂ . The lifetime and regeneration of the Co-based three-component catalyst were evaluated. After the catalyst runs for 100h, the _SO2 conversion rate and sulfur selectivity can still reach 90%. Finally, the deactivated catalyst is regenerated, and the catalyst activity can be recovered after in-situ secondary roasting and sulfidation of the catalyst in the reactor.

As can be seen from the foregoing examples, the present invention can enable the catalyst to be used for SO reduction to produce sulfur by the metal _oxide of the active component Co loaded on the carrier, and through its synergistic effect with the auxiliary agent. Higher activity and higher selectivity; and, the neutral component of the Co-based catalyst is uniformly dispersed, stable in performance and uniform in particle size, and can be used in catalytic flue gas in a fixed _- bed reactor SO2 reduces sulfur production , so that the conversion rate of SO2 can reach more _than 90%, and the selectivity can reach more than 90%.

At the same time, the catalyst of the present invention can be regenerated after being deactivated, only needs secondary roasting and sulfidation in situ, and the activity of the catalyst can be restored, thereby improving the resource recycling rate.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow process can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. one kind is used for SO in flue gas₂The Co series catalysts of reduction sulphur processed, it is characterised in that the catalyst includes carrier and painting The active component and auxiliary agent being overlying on carrier, wherein active component are Co oxide, and auxiliary agent is Cu, Ni, La, Mg, Ca or Ba In any one or at least two combination of oxides.

2. Co series catalysts according to claim 1, it is characterised in that the carrier is γ-Al₂O₃, SiO₂, TiO₂Or Any one in ZSM-5 or at least two combination；

Preferably, the carrier is the homogeneous particle of shape, preferably spherical particle and/or powder.

3. Co series catalysts according to claim 1 or 2, it is characterised in that Co in active component in the catalyst Load capacity is 3wt%~16wt%；

Preferably, Cu load capacity is 1wt%~6wt% in auxiliary agent in the catalyst；

Preferably, Ni load capacity is 1wt%~6wt% in auxiliary agent in the catalyst；

Preferably, La load capacity is 1wt%~6wt% in auxiliary agent in the catalyst；

Preferably, in the catalyst in auxiliary agent Mg load capacity 1wt%~6wt%；

Preferably, in the catalyst in auxiliary agent Ca load capacity 1wt%~6wt%；

Preferably, Ba load capacity is 1wt%~6wt% in auxiliary agent in the catalyst.

4. the preparation method of the Co series catalysts according to claim any one of 1-3, it is characterised in that the preparation method For：Active component and auxiliary agent are carried on carrier using equi-volume impregnating, through drying, roasting and vulcanization, Co systems is made and urge Agent.

5. preparation method according to claim 4, it is characterised in that the preparation method specifically includes following steps：

(1) cobalt source and promoter metal salt are mixed and made into solution；

(2) carrier is added into step (1) described solution, incipient impregnation, the carrier after being impregnated is carried out；

(3) carrier after step (2) described dipping is dried and is calcined, and obtains catalyst precursor；

(4) step (3) described catalyst precursor is vulcanized, obtains Co series catalysts.

6. the preparation method according to claim 4 or 5, it is characterised in that step (1) described cobalt source is cobalt nitrate；

Preferably, step (1) the promoter metal salt is nickel nitrate, copper nitrate, lanthanum nitrate, magnesium nitrate, calcium nitrate or barium nitrate In any one or at least two combination；

Preferably, the consumption of step (1) described cobalt source is：The load capacity for making Co in active component in the catalyst after load is 3wt%~16wt%；

Preferably, the consumption of promoter metal salt is in step (1) described solution：The load capacity for making Cu in the catalyst after load is 1%~6wt%, Ni load capacity are 1%~6wt%, and La load capacity is 1%~6wt%, Mg load capacity 1%~ 6wt%, Ca load capacity 1%~6wt%, Ba load capacity are 1%~6wt%；

Preferably, solvent is water in step (1) described solution.

7. the preparation method according to claim any one of 4-6, it is characterised in that step (2) described carrier be γ- Al₂O₃, SiO₂, TiO₂Or any one in ZSM-5 or at least two combination；

Preferably, the time of step (2) described incipient impregnation is 1h~6h；

Preferably, step (3) described drying temperature is 100 DEG C~130 DEG C；

Preferably, step (3) drying time is 1h~6h；

Preferably, the temperature of step (3) described roasting is 400 DEG C~600 DEG C；

Preferably, the time of step (3) described roasting is 6h~12h；

Preferably, step (3) roasting is carried out in Muffle furnace.

8. the preparation method according to claim any one of 4-7, it is characterised in that step (4) vulcanization is in H₂S and H₂ Mixed atmosphere under carry out；

Preferably, the H₂S and H₂Mixed atmosphere in H₂S volume content is 5%~15%；

Preferably, the temperature of step (4) described vulcanization is 400 DEG C~600 DEG C；

Preferably, the time of step (4) described vulcanization is 0.5h~6h；

Preferably, step (4) vulcanization is carried out in tube furnace.

9. the purposes of the Co series catalysts according to claim any one of 1-3, it is characterised in that by the Co series catalysts For being catalyzed SO in flue gas in fixed bed reactors₂Reduction prepares elemental sulfur；

Preferably, SO in the flue gas₂Volume content be 20%~30%.

10. purposes according to claim 9, it is characterised in that SO in the catalysis flue gas₂Reduction prepares the side of elemental sulfur Method is：

The Co series catalysts are loaded in fixed bed reactors, in discharge system after air, flue gas and coal gas are preheated extremely 300 DEG C~450 DEG C, enter back into fixed bed reactors and reacted at 350 DEG C~450 DEG C, by the SO in flue gas₂Reduction system Standby elemental sulfur.