WO2002074883A1

WO2002074883A1 - Desulfurizing agent, method for production thereof, and method of use thereof

Info

Publication number: WO2002074883A1
Application number: PCT/JP2002/002649
Authority: WO
Inventors: Michihiro Ishimori; Masafumi Katsuta; Nobuyuki Yui; Takashi Inaba
Original assignee: Waseda University
Priority date: 2001-03-21
Filing date: 2002-03-20
Publication date: 2002-09-26
Also published as: JPWO2002074883A1

Abstract

A desulfurizing agent comprising a compound represented by the general formula: ZnFe2O4/SiO2/AO2 wherein A represents Zr and/or Ti; a method for producing the desulfurizing agent which comprises adding ZrO2 and/or TiO2 to an zinc ferrite silica represented by the formula: ZnFe2O4/SiO2, followed by pulverizing and mixing, adding a forming aid to the resulting mixture and then firing; and the use of the desulfurizing agent in producing a high purity hydrogen, a highly desulfurized hydrogen, a highly desulfurized synthetic gas and a highly desulfurized reducing gas. The desulfurizing agent exhibits high performance in the desulfurization of a crude hyfrogen, a reducing gas containing hydrogen, a synthetic gas or a coal gas and also is capable of being repeatedly used in the cycle of desulfurization-regeneration, and the method allows economical and efficiet production of the desulfurizing agent.

Description

Description Desulfurization agent, method for producing the same and method for using the same

The present invention relates to a desulfurizing agent, a method for producing the same, and a method for using the same, and in particular, high purity hydrogen, highly desulfurized hydrogen, and highly desulfurized synthesis gas

(H ₂ -CO mixed gas) or renewable desulfurizing agent for producing highly desulfurizing gas, efficient production method thereof, high purity hydrogen, highly desulfurizing hydrogen using the desulfurizing agent , The application for producing highly desulfurized synthesis gas or highly desulfurizing reducible gas. Background art

In recent years, C 0 ₂ by that global warming to environmental problems in your Ri global scale Tsu Do the problems that have been attention. On the other hand, there is concern that resources such as oil will be depleted, and in response to these, high efficiency power generation coal gasification combined power generation, coal gasification fuel cell combined power generation, etc. using coal with large reserves. There are expectations for

Various methods have been proposed for directly gasifying such coal and the like and using the purified gas for power generation, for example, the above-described combined coal gasification combined cycle power generation. Such power generation gasifies coal, etc., burns the gas, drives the gas turbine, and uses the heat generated by the gasification and the heat of the exhaust gas after the gas turbine drive. It drives the steam turbine. In addition, coal was gasified using a fuel cell, for example, a molten carbonate fuel cell. Power generation methods have also been proposed to convert gas directly into electricity.

However, in such a power generation method, in order to obtain high power generation efficiency, a desulfurization method for removing sulfur compounds such as hydrogen sulfide, carbosulfide sulfur and the like is a problem.

The desulfurization methods currently used include the wet method and the dry method. The wet method has problems such as low desulfurization temperature and large energy loss. On the other hand, the dry method has small energy loss but high desulfurization temperature and can be used commercially. The desulfurization system has not been developed yet. Iron oxide and zinc oxide are commonly used dry desulfurization agents.

In addition, iron oxide as a conventional dry desulfurization agent can not remove sulfur compounds to a great extent. Therefore, iron oxide can not be used to significantly reduce the performance due to the presence of sulfur compounds such as fuel cells, and it is sufficient as a desulfurization agent. Performance is not available.

Furthermore, zinc oxide, which is used as a desulfurization agent, has a low absorption capacity for sulfur compounds and is difficult to regenerate, so it is possible to use it as a desulfurization agent for coal gasification for power generation, for example. If you use a tray, the amount of desulfurization agent required will be extremely large.

In addition, as a hydrogen production method using advanced desulfurization methods for natural gas, there is a natural gas reforming method. A conventional method for producing such advanced desulfurization hydrogen, which can be used for fuel cells etc., is a process that can be used for fuel cells etc., by converting natural gas into highly desulfurized hydrogen. And desulfurize hydrogen sulfide with zinc oxide etc. to obtain highly desulfurized natural gas. Next, the highly desulfurized natural gas obtained was Highly desulfurized hydrogen is obtained by feeding to the reformer. However, with such conventional natural gas desulfurization methods, the used zinc oxide etc. can not be disposed of and reused. In addition, when the concentration of hydrogen sulfide contained in natural gas is high (30 to 100 ppm), rough desulfurization using MDEA (amino) etc. is carried out before precision desulfurization. It will need to be implemented, and the process will be complicated.

In order to solve these problems, JP-A-4-174526 discloses a method of producing zinc ferrite used as a desulfurization agent. Such zinc ferrite as a desulfurization agent is intended to improve the removal efficiency of sulfur compounds and to further improve its absorption capacity by using a zinc-iron double oxide. It is

When the zinc ferrite desulfurization agent is used in the desulfurization process, the above-mentioned zinc ferrite desulfurization agent decomposes the desulfurization agent or precipitates carbon in the desulfurization agent, and the pore of the desulfurization agent to which the sulfur compound gas diffuses In addition, the desulfurization efficiency has been reduced by closing down the catalyst and generating byproducts that do not contribute to the desulfurization. Also, the desulfurization performance of the desulfurization agent after regeneration is significantly reduced.

Also, Zn F e ₂ 0 ₄ with the addition of shea Li Ca Zinc full E Lai DOO as a desulfurizing agent - S i 0 ₂ also being proposed. Such a desulfurization agent, the also ZnF e ₂ 0 ₄ to S i 0 ₂ a by Ri desulfurization performance and the child to be added is improved, the desulfurization performance after play had island decreased rather than the remarkable, repeat play Ri It was difficult to use it.

Therefore, the object of the present invention is to provide a high degree of repeatability for desulfurization and regeneration. Supply desulfurization agent.

Another object of the present invention is to provide a process for producing a desulfurizing agent which can produce such desulfurizing agent economically and efficiently. Another object of the present invention is to provide a method of using such desulfurizing agents to produce high purity hydrogen, highly desulfurized hydrogen, highly desulfurized synthesis gas or highly desulfurizable gas. Disclosure of the invention

The present inventors have results studied for solving the above problems, the _{_{_{ZnFe 2 0 4 / Si0 2,}}} ( in the formula, A represents the Zr and / or Ti) A0 ₂ Ri by the and this you added, The inventors have found that the desulfurization performance is improved, and that the desulfurization agent in which the desulfurization performance does not deteriorate even after repeated use is obtained, and the present invention has been achieved.

Desulfurization agent of the present invention have the general _{_{_{formula; ZnFe 2 0 4 / Si0 2}}} / A0 2 ( in the formula, A represents the Zr and / or Ti) and Oh Ru This desulfurization agent comprising a compound table with It is characterized by The _{_{_{ZnFe 2 O 4 / Si0 2 /}}} A0 2 means _{_{_{(ZnFe 2 0 4) p (}}} Si0 2) q (A0 2) r (p, q, r denotes any number) (A is Zr And / or indicate Ti).

Further, according to the method for producing the desulfurizing agent of the present invention, the following formula is used to produce the desulfurizing agent of the present invention: zinc ferrite represented by the following formula: ZnFe ₂ O ₄ / Si 0 ₂ a, (in the formula, a represents the Zr and / or Ti) A0 ₂ were ground and mixed by adding, characterized that you firing by adding a molding aid to the mixture obtained.

Preferably, in the method for producing a desulfurizing agent according to the present invention, the zinc ferrite silica is a mixed solution of an aqueous solution of zinc and an aqueous solution of iron. The solution is applied with silica sol, precipitated with ammonia or urea, and then filtered, washed, dried, and calcined to obtain a feature.

Moreover, the method of using the desulfurizing agent of the present invention comprises using the above-mentioned desulfurizing agent of the present invention for desulfurizing crude hydrogen, synthesis gas, hydrogen-containing reducing gas, synthesis gas, natural gas or coal gas. It is a feature.

Preferably, in the method of using the desulfurizing agent of the present invention, the desulfurizing agent used is regenerated by oxidation, and the regenerated desulfurizing agent is repeatedly used. Brief description of the drawings

FIG. 1 is a graph showing the desulfurization regeneration characteristics of the desulfurization agent (ZnFe ₂ O ₄ / Sio ₂ / Zr 0 ₂ ) of the present invention as a function of time and hydrogen sulfide concentration (desulfurization agent: oxidation regeneration method; hydrogen sulfide Concentration: Desulfurizer exhaust gas).

Fig. 2 is a diagram showing the desulfurization regeneration characteristics of the desulfurization agent (ZnFe ₂ O ₄ / Sio ₂ / Ti 0 ₂ ) of the present invention as a function of time and hydrogen sulfide concentration (desulfurization agent: oxidation regeneration method; hydrogen sulfide Concentration: Desulfurizer exhaust gas).

Fig. 3 is a diagram (Desulfurization agent: Regeneration system; Hydrogen sulfide concentration: Desulfurization device outlet gas) showing the desulfurization and regeneration characteristics of the conventional desulfurization agent as a function of time and hydrogen sulfide concentration. .

Fig. 4 is a diagram showing the relationship between the number of desulfurization cycles and the amount of absorbed hydrogen sulfide for the desulfurizing agent of the present invention (ZnFe ₂ 0 ₄ / Si 0 ₂ / Zr 0 ₂ ) and the conventional desulfurizing agent. Ru. FIG. 5 is a graph showing the relationship between the number of desulfurization cycles and the amount of absorbed hydrogen sulfide for the desulfurizing agent (ZnFe ₂ O ₄ / Si 0 ₂ / Ti 0 ₂ ) of the present invention.

Fig. 6 is a diagram showing the desulfurization regeneration characteristics of the desulfurization agent (ZnFe ₂ O ₄ / Sio ₂ / Zr 0 ₂ ) of the present invention as a function of time and hydrogen sulfide concentration (desulfurization agent: oxidation regeneration · reduction treatment method Hydrogen sulfide concentration: Desulfurizer outlet gas).

Fig. 7 is a diagram showing the relationship between the number of desulfurization cycles and the amount of absorbed hydrogen sulfide in relation to the hydrogen reduction treatment for the desulfurization agent (ZnFe ₂ 0 ₄ / Si 0 ₂ / Zr 0 ₂ ) of the present invention. is there.

Fig. 8 is a graph showing the desulfurization regeneration characteristics (desulfurization temperature) of the desulfurization agent (ZnFe ₂ 0 ₄ / Si 0 ₂ / Zr 0 ₂ ) of the present invention as a function of time and hydrogen sulfide concentration (desulfurization agent: oxidation Regeneration method: Hydrogen sulfide concentration: Desulfurization unit outlet gas).

FIG. 9 is a graph showing the desulfurization regeneration characteristics (desulfurization temperature) of the desulfurization agent (ZnFe ₂ O ₄ / Sio ₂ / Ti 0 ₂ ) of the present invention as a function of time and hydrogen sulfide concentration (desulfurization agent: oxidation Regeneration method: Hydrogen sulfide concentration: Desulfurization unit outlet gas). BEST MODE FOR CARRYING OUT THE INVENTION

The invention will be described on the basis of the following preferred examples.

The preferred desulfurizing agent of the present invention comprises a compound represented by the following general formula: ZnFe ₂ O ₄ / Sio ₂ / A 0 ₂ (wherein A represents Zr and / or Ti). Zr0 ₂ or Ti0 ₂ in the above formula has a function as a ZnFe _₂ 0 ₄ / Si0 ₂ of the structural stabilizer. In addition to the Zr0 ₂ and Ti0 _2, Ri was using the A1 ₂ 0 _3, Or A1 ₂ 0 ₃ and Zr0 combination with ₂ or Ti0 ₂ also Ru can this and force S to be used.

Particularly high-performance of a point or these desulfurizing agent after regeneration, Ti0 ₂及Pi / or Zr 0 ₂ is suitably use Rere.

Zr0 ₂ and Ti0 ₂ in which these structures stabilizer to this stabilizes the binding of ZnFe ₂ 0 ₄ and Si_〇 _2, the aggregation of zinc Fe Rye preparative that put the regeneration process after the desulfurization Has a function that can be prevented.

The method for producing the desulfurizing agent of the present invention is described below.

As the production method, a precursor of iron oxide and zinc oxide and a precursor of silicon oxide are mixed, and iron, zinc and silicon in the form of hydroxide by coprecipitation method or homogeneous precipitation method. to form a sediment containing the ingredient, filtered, washed, dried, Ri by the and this firing, Ri by the and this is pulverized if necessary to be al, Zn Fe ₂ 0 ₄ - Si0 ₂ to be produced.

The form of addition of silicon is not particularly limited as long as zinc, iron and silicon can interact with each other.

The mixing ratio of zinc oxide and iron oxide is not particularly limited, but the molar ratio is preferably 1: 2 to 1: 4, preferably 1: 2 to 1: 3 depending on the amount of the desulfurizing agent used. Preferred in terms of desulfurization efficiency. In addition, the amount of silicon oxide added is also not particularly limited, and it is l ZASZ l with respect to the weight of the force S, ZnFe ₂ 0 ₄ -Si 0 ₂ is the point of the desulfurization performance of the obtained desulfurization agent I like it.

As a precursor of iron oxide or zinc oxide, for example, water soluble salts such as nitrate, sulfate and chloride can be used. In addition, silicon is a precursor of silicon oxide, such as citric acid, cobalt oxide, and It is possible to use an Amorphous System, etc.

Specifically, after stirring an aqueous solution in which these iron precursors, zinc precursors, and silicon precursors are mixed, a coprecipitation method using ammonia etc. or urea etc. is used. The precipitate is obtained as hydroxide by the homogeneous precipitation method. Sodium hydroxide and potassium hydroxide can also be used as other additives to obtain precipitates. The precipitate is aged, washed, filtered, dried, and calcined at a temperature of 300 to 900 ° C., for example. If necessary, ZnF e ₂ 0 ₄ -S i 0 ₂ is produced by grinding the obtained fired product.

Then, the resulting ZnF e ₂ 0 ₄ - adding Zr0 ₂及Pi / or Ti 0 ₂ of the structure stabilizer S i 0 ₂ baked product. The Collector et mixture was mixed and ground, Ri by the and this firing by adding a molding aid to the mixture obtained, ZnF of the present invention _{_{e 2 0 4 - S i 0}} 2 - A0 2 ( in the formula, A represents Zr and / or Ti).

The amount of added Zr0 ₂ or Ti 0 ₂ is not particularly limited, preferably ZnFe ₂ 0 ₄ - in pairs on the weight of the S i 0 _2, about 1 to 3 times, to obtain a desulfurizing agent It is preferable from the point of maintaining desulfurization performance even after regeneration.

When forming desulfurization agents, as a forming aid, methyl cellulose, polyethyl alcohol, poly alcohol, starch, starch, Organic substances such as lignin can be used. It is also possible to add inorganic agents such as glass fiber, carbon fiber and metal fiber for molding.

The calcination is then carried out at a temperature of 400 to 700 ° C., for example, granular, In the present invention, it can be formed by firing into any desired desired shape such as pellet, sphere, cylinder, cavity, cam and plate.

ZnF e ₂ 0 ₄ -S i 0 ₂ -A 0 ₂ (wherein, A represents Zr and / or Ti) A desulfurizing agent is obtained.

The desulfurization agent of the present invention thus obtained can be suitably used for desulfurization of crude hydrogen, synthetic gas, hydrogen-containing reducing gas, natural gas or coal gas. The desulfurization temperature is not particularly limited, and desulfurization at a temperature of 300 to 600 ° C. is preferable.

For example, it can be applied to a natural gas reforming method that produces high purity hydrogen by highly desulfurizing natural gas. In the present invention, natural gas is first desulfurized by passing through a desulfurizer, then desulfurized gas is passed through a reformer, and part of the H2 gas reformed by the reformer is passed through the reformer. For example, by returning about 5% of hydrogen gas to the upstream of the desulfurization apparatus, the natural gas flowing into the desulfurization apparatus is treated as a hydrogen-containing reducible natural gas, and is contained in the desulfurization apparatus. A highly desulfurized hydrogen-containing natural gas is obtained by the desulfurizing agent. Then, the highly desulfurized hydrogen-containing natural gas is fed into the reformer to obtain highly dehydrogenated hydrogen. is there.

In addition, after being used as a desulfurizing agent, the desulfurizing agent of the present invention can be regenerated by oxidation, and the regenerated desulfurizing agent can be used repeatedly. Desulfurization performance does not deteriorate even with such repeated use. This is cormorants I described above, in the structure of the desulfurization agent of the present invention, Zr0 ₂ and Ti 0 ₂ force S, to stabilize the bond between ZnFe ₂ 0 ₄ and S i 0 _2, reproduction process after the desulfurization In the country This is because it has a function that can prevent light aggregation.

In addition, even when the concentration of hydrogen sulfide contained in natural gas is high (for example, about 30 to: I 0 0 0 pp m), MDEA, which was conventionally required before precision desulfurization, There is no need to carry out rough desulfurization using (amino) etc.

Thus, by using the desulfurizing agent of the present invention, high purity hydrogen, high desulfurization hydrogen, highly desulfurized synthesis gas or highly desulfurized reduction gas can be easily and economically obtained. Therefore, synthetic gas for coal gasification such as coal gasification combined power generation, synthesis gas for liquid fuel synthesis such as methanol, etc., and phosphoric acid type fuel cell, solid material whose electrode is easily deteriorated by reaction with hydrogen sulfide etc. It is also industrially very effective in the field (1 ppm or less) where the allowable sulfide concentration in hydrogen gas is severe, such as fuel cells such as polymer fuel cells, molten carbonate fuel cells or solid electrolyte fuel cells. is there.

In addition, methanol synthesis, dimethyl ether synthesis, high-quality diesel by reaction of hydrogen and carbon monoxide using a copper-based catalyst or the like that is easily degraded by reaction with hydrogen sulfide. Also in fuel oil (T-F hydrocarbon) synthesis, high purity hydrogen, highly desulfurized hydrogen or synthesis gas obtained using the desulfurization agent of the present invention can be effectively used. Example

The present invention will be further described specifically by the following examples, comparative examples and test examples, but the present invention is limited to these examples. It's not.

Example 1

Aqueous solution of zinc nitrate (. 1 5 mol / 1) 5 0 ml iron nitrate aqueous solution (. 1 5 mol / 1) was mixed with 100 ml, a co B A Darcy Li mosquitoes, resulting ZnFe _₂ 0 ₄ - Si0 ₂ of The mixture was added and stirred in an amount corresponding to 1/3 of the weight. The pH of the solution was adjusted to 7 to 8 by adding ammonia to the obtained mixture, and the hydroxide was coprecipitated. The resulting hydroxides are aged for 1 hour, filtered, washed with pure water, dried at 120 ° C for 12 hours, then fired at 80 ° C for 5 hours, and the mortar is and Kona碎using, ZnFe ₂ 0 ₄ - was obtained Si0 _2. Then, the resulting ZnFe ₂ 0 ₄ - Si0 ₂ to be paired with the addition of Zr0 ₂ of 2 times by weight, the rig two down of the forming aid is added 5% of the total weight, mortar Mixed at the same time. The substance obtained by mixing is formed into a tablet shape with a tablet molding machine, dried, and fired at 500 ° C. for 3 hours, and the baked product is ground in a mortar. The particles were classified into an average particle size of 500 to 700 μm to obtain a ZnFe ₂ 0 ₄ / Si 0 ₂ / Zr 0 ₂ desulfurizing agent of the present invention.

Example 2

Was used in place Zr0 ₂ to Ti0 ₂ were obtained in the same manner _{_{_{ZnFe 2 0 4 / Si0 2 /}}} Ti0 2 desulfurizing agent of the present invention.

Comparative example 1

But replacing Zr0 ₂ to Si0 _2, with the _₂ 0 ₄ / Si0 ₂ desulfurizing agent ZnFe in the same manner as in Example 1, it was desulfurizing agent for comparison.

Test example

Desulfurization test and regeneration test

The desulfurizing agent obtained in Example 1 and Example 2 and Comparative Example 1 was used. The desulfurization test and regeneration test were conducted using the fixed bed flow reactor described below.

Reaction tube: made of quartz glass, inner diameter 7. 6 outer diameter 0 0 step length 4 0. 0 mm

(1) Desulfurization test conditions

Pressure Normal pressure

Temperature 450 ° C (or 250 ° C to 600 ° C)

Gas composition H ₂ S lOOOOppm

H ₂ 20% by volume

N balance (80% by volume)

Gas flow rate 100 nU / min

Desulfurization agent sample weight 600 mg (200 mg of ZnFe ₂ O ₄ / Sio ₂ + 400 mg of Z r 0 ₂ , Ti 0 ₂ or Sio ₂ )

(2) Regeneration test conditions

Pressure Normal pressure

450 ° C

Gas composition Oxidation regeneration (60 minutes) 0 ₂ 2% by volume

N ₂ 98 volume%

Reduction treatment (10 minutes) H ₂ 20% by volume

N ₂ 80% by volume

Gas flow rate 1 OO ml / min

Desulfurization agent sample weight 600 mg (200 mg of ZnFe ₂ O ₄ / Sio ₂ + 400 mg of Z r 0 ₂ , Ti 0 ₂ or Sio ₂ ) 1 minute or less maintenance time (minute) (N desulfurization)

Reproduction rate (%) = X 1 0 0

Maintenance time of 1 ppm or less (minute) (first desulfurization)

Test example 1

The desulfurizing agents obtained in Example 1 and Example 2 and Comparative Example 1 are desulfurized under the above desulfurization conditions (desulfurization temperature is 450 ° C.), and then oxidation regeneration is repeated under the above regeneration conditions and repeated. Returned desulfurization test. The results are shown in Fig. 1, Fig. 2 and Fig. 3 respectively. Desulfurization reaction In order to investigate the change in high-performance desulfurization time in which the hydrogen sulfide concentration in the gas at the outlet of the pipe is maintained at 1 ppm or less, using the above equation representing the regeneration rate based on the first time, The playback rate was calculated.

By comparing the regeneration rates shown in Fig. 1, Fig. 2 and Fig.

The desulfurization agent obtained in Example 1 and Example 2 is found to have superior desulfurization performance even after the regeneration treatment than the desulfurization agent obtained in Comparative Example 1.

Figure 4 shows the relationship between the number of desulfurization cycles in the desulfurizing agent and the amount of absorbed hydrogen sulfide in Example 1 and Comparative Example 1, and Figure 5 shows the number of cycles in the desulfurizing agent of Example 2. The relationship between and hydrogen sulfide absorption is shown. The experimental values, according to the area of the graphs in Fig. 1, Fig. 2 and Fig. 3 (diagram integral), H ₂ S theoretical absorption value is ZnFe ₂ 0 ₄ 3 mol, Fe ₂ 0 ₃ is The ZnFe ₂ 0 ₄ / S 0 ₂ Ti ₂ O ₂ -based desulfurizing agent was calculated based on the assumption that 2 moles and 1 mole of ZnO absorb 1 mole of H ₂ S. The desulfurizing agent based on ZnFe ₂ O ₄ was superior to the viewpoint of H ₂ S absorption capacity. Desulfurizing agent, H ₂ S absorption actually measured value is higher than theoretical value It was a good value. This result suggests that the desulfurization reaction as in Reaction formula 2 is also performed in addition to the desulfurization reaction formula (1) conventionally assumed as the desulfurization reaction mechanism. it is conceivable that.

Reaction formula 1 ZnFe ₂ 0 ₄ + 3H ₂ S + H ₂ → ZnS + 2FeS + 4H ₂ 0

(1) Scheme _{_{2 ZnFe 2 0 4 + 4 H}} 2 S → ZnS + FeS + FeS 2 + 4H 2 0

(2) From the comparison of the absorption capacities of hydrogen sulfide shown in FIGS. 4 and 5, the desulfurizing agents obtained in Example 1 and Example 2 can be compared with the desulfurizing agents obtained in Comparative Example 1 as well. It is possible to have excellent desulfurization performance even after regeneration treatment.

It is considered that this is because the desulfurizing agent of Comparative Example 1 was broken during regeneration between the zinc ferrite and the silica during regeneration, and the zinc ferrite was agglomerated. On the other hand, as described above, the desulfurizing agents of Example 1 and Example 2 were able to maintain excellent desulfurization performance even after regeneration, as described above, because the bonding between zinc ferrite and silica was not effective. It is believed that near stability has been achieved and zinc ferrite aggregation has been prevented.

Test example 2

The desulfurization agent obtained in Example 1 is desulfurized under the above desulfurization conditions (desulfurization temperature is 45 ° C.), and then oxidized and regenerated under the above regeneration conditions, and then the H ₂ reduction treatment is carried out. It is now. The result is shown in Fig.6. The calculation of the regeneration rate was the same as in Test Example 1. Also, in order to compare the influence of H ₂ reduction treatment on the desulfurization performance, as shown in FIG. 7, after the desulfurization agent obtained in Example 1 is oxidized and regenerated, H ₂ Show the relationship between the number of desulfurization cycles and the amount of absorbed hydrogen sulfide, with and without reduction treatment. Experimental values and theoretical values are test examples

Calculated in the same way as 1).

The purpose of H ₂ reduction is considered to be Fe S → F e S 0 _{4 in} the side reaction during regeneration treatment, and H ₂ reduction using Fe S 0 ₄ → Fe ₃ 0 _{4 is} considered It is for the future. As shown in Fig. 7 and Fig. 7, no difference was seen in the desulfurization performance regardless of whether or not the H ₂ reduction treatment was used. This desulfurization agent of the present invention, the generation of F e S 0 ₄ that Ji by Ri production in side reactions during playback Ru Oh than also indicating the this Ru small amount der.

Test example 3

The desulfurization performance of the desulfurization agent obtained in Example 1 and Example 2 is the same as in Example 1 except that the desulfurization temperature is changed. The results are shown in FIGS. 8 and 9, respectively. Show. The calculation of the regeneration rate was the same as in Test Example 1. It can be seen from FIGS. 8 and 9 that the desulfurizing agent of the present invention can perform high-performance desulfurization particularly in the temperature range of 250 and at 600 °. Industrial applicability

The desulfurizing agent of the present invention is a high-performance desulfurizing agent capable of repeated desulfurization and regeneration, and using such a desulfurizing agent, high purity hydrogen, high dehydrogenation hydrogen, high desulfurization synthesis gas or high desulfurization agent It is easy to economically produce desulfurization reducing gas. Therefore, synthesis gas for coal gas such as coal gasification combined generation, liquid fuel synthesis such as methanol, etc., phosphoric acid type whose electrode is easily deteriorated by reaction with hydrogen sulfide etc. It is also very useful industrially in areas where the concentration of sulfides in hydrogen gas is severe (for example, less than about 1 ppm), such as fuel cells and fuel cells such as molten carbonate fuel cells. It is possible. Moreover, the method for producing a desulfurizing agent of the present invention is capable of economically and efficiently producing the desulfurizing agent of the present invention.

Claims

Request

The following general formula;

ZnFe ₂ 0 ₄ / S i 0 ₂ / A 0 ₂

(Wherein, A represents Zr and / or Ti)

A desulfurization agent characterized by containing a compound represented by

. 2 Ri per To produce the desulfurizing agent in the range first claim of claim, the following formula: in _{_{ZnF e 2 0 4 / S i0}} 2 at INDICATED the zinc off E Rye preparative Shea Li Ca, A0 ₂ (In the formula, A represents Zr and / or Ti), and the mixture is pulverized and mixed, and a forming auxiliary agent is added to the obtained mixture and the mixture is calcined.

In the method for producing a desulfurizing agent according to claim 2, the zinc ferrite sol is added to the mixed solution of an aqueous solution of zinc and iron, and the ammonia sol is added to the ammonia desulfurization agent. A method for producing a desulfurization agent, which is obtained by precipitation using a or urea, followed by filtration, washing, drying and calcination.

4. Use of a desulfurizing agent characterized in that the desulfurizing agent according to claim 1 is used for desulfurizing crude hydrogen gas, synthesis gas, reducing gas containing hydrogen, natural gas, or coal gas. Method.

5. The method for using a desulfurizing agent according to claim 4, characterized in that the desulfurizing agent used is regenerated by oxidation, and the regenerated desulfurizing agent is repeatedly used. How to use desulfurization agent