JP3017730B1 - Dry desulfurizing agent, method and apparatus for producing the same, and method and apparatus for using the desulfurizing agent - Google Patents

Abstract

A dry desulfurization agent for reversibly removing a sulfur compound from a gasification gas such as a coal gasification gas, which withstands repetition of a cycle of sulfidation and regeneration, and which can be used even in a middle temperature range of 600 ° C or lower. Provided is a dry desulfurizing agent that does not lose reactivity and does not cause mechanical deterioration. SOLUTION: A moving bed type dry coal gas in which a zinc oxide and a zirconium oxide are supported on porous particles of ceramics such as silica / alumina, mullite or zirconia to produce a dry desulfurizing agent and desulfurization and dust removal can be performed simultaneously. Used in chemical purifiers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coal gasification gas,
Dry desulfurizing agent for removing sulfur compounds such as hydrogen sulfide and carbonyl sulfide from a reducing gas generally containing a sulfur compound such as petroleum gasified gas, a method and apparatus for producing the same, and a method for using the dry desulfurizing agent It relates to the device used.

[0002]

2. Description of the Related Art Gas obtained by gasifying fossil fuels such as coal and petroleum contains sulfur compounds such as hydrogen sulfide and carbonyl sulfide. Therefore, from the viewpoint of preventing corrosion of various devices and preventing air pollution. Prior to using gasified gas as fuel gas for power generation equipment such as gas turbines and molten carbonate fuel cells, sulfur compounds are removed. As a conventional method for removing sulfur compounds, a high-temperature dry desulfurization method is used.For example, a coal gasification gas is introduced into a moving-bed gas refining device, and a gas-solid reaction between the gas and a desulfurization agent at a high temperature is performed in the gas. The sulfur-removed gas is removed at the same time as the removal of sulfur compounds, and the gas subjected to desulfurization and dust removal is used as a fuel gas for gas turbines and the like.

[0003] JP-A-5-239475 describes a dry desulfurization method and apparatus in which a coal gasification gas containing hydrogen sulfide is passed through a desulfurizer filled with zinc oxide as a fixed bed to perform dry desulfurization. . Also, Japanese Patent Application Laid-Open No. 7-25609
No. 3 produced a durable pellet containing zinc oxide for removing hydrogen sulfide from coal gasification gas, containing titania as a diluent, high surface area silica gel as a matrix material, and a binder. A durable zinc oxide containing sorbent for coal gas desulfurization is described.

[0004]

The properties of the gasified gas before the removal of the sulfur compound vary depending on the gasification furnace system, and the allowable concentration of the sulfur compound that can be used as a fuel gas is not limited. Varies depending on the type of
Conventionally, desulfurizing agents such as iron oxides and zinc ferrite have been used for those having a relatively high moisture concentration in the gasified gas. When used as a fuel gas for power generation equipment such as a molten carbonate fuel cell having a low allowable concentration of a sulfur compound, a zinc-based desulfurizing agent such as zinc titanate has been used. In the former desulfurizing agent, carbon is precipitated for a gasified gas having a very low moisture concentration,
There is a problem that the mechanical strength of the desulfurizing agent deteriorates while the cycle of desulfurization and regeneration is repeated, and in the latter desulfurizing agent, the desulfurization reaction does not easily proceed unless the desulfurization temperature is maintained at a high temperature of 600 ° C. or higher. There was a disadvantage.

In the technique described in Japanese Patent Application Laid-Open No. 5-239475, dry desulfurization is carried out using zinc oxide as a fixed layer. Mechanical strength cannot be obtained. Further, in the technology described in Japanese Patent Application Laid-Open No. 7-256093, since titania is used at the time of preparing the sorbent (adsorbent), the performance is high at high temperatures, but the performance decreases at low temperatures, and it is confirmed by preliminary tests. Have been. Coal gasification gas is cooled from 343 ° C (650 ° F) to 538 ° C (1000 °
Although it is said that the dry desulfurization in the temperature range of F) maximizes the economy of the entire system, the development of the desulfurizing agent used at that time has not been fully established at present. Conventionally, a desulfurization agent was developed for a process that individually performs desulfurization and dust removal. However, by developing a desulfurization agent (desulfurization and dust removal agent) that can perform desulfurization and dust removal simultaneously, the entire process has been developed. The economy is improved.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a gaseous gas having a low water concentration without deteriorating the mechanical strength of a desulfurizing agent due to carbon precipitation or the like, and To provide a high-temperature dry desulfurizing agent exhibiting high reactivity to hydrogen sulfide over a long period of sulfurization and regeneration cycles, a method and an apparatus for producing the same, and a method and an apparatus for using the same. Another object of the present invention is to increase the content of zinc oxide for removing sulfur compounds, and to improve the dispersibility of zinc oxide, and to add high-temperature dry desulfurization by adding zirconium oxide. An object of the present invention is to provide an agent, a method and an apparatus for producing the same, and a method and an apparatus for using the same. Another object of the present invention is to provide a high-temperature dry desulfurizing agent having excellent mechanical durability with less deterioration in mechanical strength due to repetition of a cycle of sulfuration and regeneration, a method and apparatus for producing the same, and a method and apparatus for using the same. To provide. Another object of the present invention is to use as a fuel gas when using a power generation system with high power generation efficiency such as a molten carbonate fuel cell without losing reactivity even in a medium temperature range of 600 ° C. or lower. An object of the present invention is to provide a dry desulfurizing agent that can be used, a method and apparatus for producing the same, and a method and apparatus for using the same. Further, another object of the present invention is to have a mechanical strength enough to be used in a moving bed type gas purifier capable of simultaneously performing desulfurization and dedusting, and to avoid spalling during repeated cycles of desulfurization and regeneration.
An object of the present invention is to provide a high-temperature dry desulfurizing agent having high reactivity and durability, a method and an apparatus for producing the same, and a method and an apparatus for using the same.

[0007]

In order to achieve the above-mentioned object, the dry desulfurizing agent of the present invention is constituted such that zirconium is added to zinc to increase the loading amount and improve the dispersibility. You. Further, the dry desulfurizing agent of the present invention comprises zinc oxide (ZnO) for removing sulfur compounds and a binder.
Zirconium oxide (zirconia, Z
rO ₂ ) is supported by porous particles of ceramics such as silica / alumina, mullite or zirconia (hereinafter sometimes simply referred to as “ceramics”). In this case, 0.1 to 12% by weight, preferably 3 to 6% by weight of zinc oxide, 0.1 to 14% by weight, preferably 4 to 8% by weight of zirconium oxide, and 74 to 99.8% of porous particles. % By weight, preferably 86 to 93% by weight. As described above, porous particles such as mullite, silica / alumina, and zirconia are used as the porous particles. The dry desulfurizing agent of the present invention uses porous particles made of ceramics as a desulfurizing agent carrier in order to have mechanical strength that can withstand high temperature and high pressure such as a moving bed type gas purifying device. Further, by adding zirconium oxide, the content of zinc oxide in the desulfurizing agent for removing sulfur compounds can be increased. Furthermore, by adding zirconium oxide, the dispersibility of zinc oxide for removing sulfur compounds in a desulfurizing agent can be improved. In addition, the reactivity can be maintained even in a middle temperature range of 600 ° C. or lower. The dry desulfurizing agent of the present invention is particularly suitable for use as a dry desulfurizing agent for removing a sulfur content in a reducing gas such as a coal gasification gas.

The process for producing a dry desulfurizing agent according to the present invention is characterized in that a ceramic porous body such as silica-alumina, mullite or zirconia is used as a carrier and a solution containing at least one of zinc nitrate, zinc sulfate and zinc chloride, that is, a zinc-containing solution And a solution containing at least one of zirconium nitrate, zirconium sulfate and zirconium chloride, that is, a zirconium-containing solution is impregnated and fired. Further, the method for producing a dry desulfurizing agent of the present invention is characterized in that ceramic powder such as silica / alumina, mullite or zirconia is kneaded with zinc and zirconium, formed into particles or a honeycomb, and then fired. . Further, in the method for producing a dry desulfurizing agent of the present invention, after a zinc-containing solution and a zirconium-containing solution are mixed to form an adjusted aqueous solution, porous particles made of a ceramic serving as a carrier are deposited and left in the adjusted aqueous solution. After the porous particles are impregnated with the adjusted aqueous solution, the adjusted aqueous solution containing the porous particles impregnated with the adjusted aqueous solution is heated, evaporated, concentrated, and dried to support the zinc compound and the zirconium compound on the porous particles. It is characterized in that porous particles supporting a zinc compound and a zirconium compound are fired.

Further, in the method for producing a dry desulfurizing agent of the present invention, an adjusted aqueous solution is obtained by mixing at least one of zinc nitrate, zinc sulfate and zinc chloride with at least one of zirconium nitrate, zirconium sulfate and zirconium chloride and water. Thereafter, porous particles made of ceramics as a carrier are deposited and left in the adjusted aqueous solution to impregnate the porous particles with the adjusted aqueous solution, and then the adjusted aqueous solution containing the porous particles impregnated with the adjusted aqueous solution is heated and evaporated. It is characterized in that after the zinc compound and the zirconium compound are supported on the porous particles by concentration and drying, the porous particles supporting the zinc compound and the zirconium compound are fired (see FIG. 1). In these production methods, after firing,
It is preferable that the metal compound attached to the surface be scraped off by an automatic sieve or the like (see FIG. 1).

[0010] The apparatus for producing a dry desulfurizing agent of the present invention comprises a stirring / mixing means for stirring / mixing a zinc-containing solution and a zirconium-containing solution into an adjusted aqueous solution, for example, a stirring / mixing tank; A sedimentation / leaving / impregnation means for depositing / leaving the porous particles made of ceramics and impregnating the porous particles with the conditioning aqueous solution, for example, a settling tank, and a conditioning aqueous solution containing the porous particles impregnated with the conditioning aqueous solution. Heating, evaporating, concentrating, drying and heating / evaporating / concentrating / drying means for supporting the zinc compound and the zirconium compound on the porous particles, for example, an evaporator, and porous particles supporting the zinc compound and the zirconium compound. And a firing furnace for firing.
In this manufacturing apparatus, it is preferable to provide a surface scraping means for scraping off a metal compound attached to the surface of the fired product, for example, an automatic sieve.

The method of using the dry desulfurizing agent of the present invention is characterized in that the dry desulfurizing agent produced as described above is used in a moving bed type dry gas purifier capable of simultaneously performing desulfurization and dust removal. (See FIGS. 2 and 3). The method for using the dry desulfurizing agent of the present invention is characterized in that the dry desulfurizing agent produced as described above is used in a fixed-bed desulfurizing apparatus. Further, the method of using the dry desulfurizing agent of the present invention is characterized in that the dry desulfurizing agent produced as described above is used in a fluidized bed desulfurizing apparatus. In these usage methods, it is particularly effective and desirable to use a desulfurizing agent to desulfurize a reducing gas such as a coal gasification gas.

The apparatus for using a dry desulfurizing agent according to the present invention is characterized by comprising a moving bed simultaneous desulfurization / dust removing apparatus using the dry desulfurizing agent produced as described above as a desulfurizing / dust removing agent. 2 and 3). Further, the apparatus for using a dry desulfurizing agent of the present invention is characterized by comprising a fixed bed desulfurizing apparatus using the dry desulfurizing agent produced as described above as a desulfurizing agent. Further, the apparatus for using a dry desulfurizing agent of the present invention is characterized by comprising a fluidized bed desulfurizing apparatus using the dry desulfurizing agent produced as described above as a desulfurizing agent.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications. FIG. 1 shows steps of a method for producing a dry desulfurizing agent according to a first embodiment of the present invention. First, 10 g to 200 g of zinc nitrate hexahydrate, 10 g to 200 g of zirconium nitrate dihydrate, and 10 g to 200 g of distilled water are put into mixing tanks at appropriate ratios and mixed with stirring. Mullite (porous solid) composed of a silica / alumina component serving as a desulfurizing agent carrier is deposited on the zinc-containing aqueous solution (adjusted aqueous solution) prepared in this manner in an amount of 10 cc to 200 cc, and left for a while to be impregnated. Next, the above-mentioned metal-containing solution is concentrated under a negative pressure by an evaporator, and a metal compound is supported on pores in the desulfurizing agent carrier. The prepared desulfurizing agent is transferred to a firing furnace and fired in air at a temperature in the range of 500 ° C to 900 ° C. At this time, zinc nitrate changes to zinc oxide, and zirconium nitrate changes to zirconium oxide. Then, the metal species only adhering to the surface were scraped off with a sieve,
Prepare a desulfurizing agent of about mm. In addition, instead of zinc nitrate,
Alternatively, zinc sulfate and zinc chloride can be used together with zinc nitrate. Further, zirconium sulfate or zirconium chloride can be used instead of or together with zirconium nitrate.

[0014]

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention. Example 1 70 g of zinc nitrate hexahydrate, zirconium nitrate dihydrate 6
8 g and distilled water (100 g) were placed in a mixing vessel and stirred and mixed to obtain an adjusted aqueous solution. 50 cc of porous particles (average particle size: 1.0 mm) composed of a silica / alumina component were added to the adjusted aqueous solution, and the resulting solution was allowed to stand for 60 minutes. Subsequently, the porous particles and the adjusted aqueous solution were transferred to an eggplant-shaped flask, and heated while keeping the inside of the system under a negative pressure to evaporate water, and concentrated and dried. Next, the dried porous particles were transferred to a firing furnace and fired at 700 ° C. to obtain a desulfurizing agent. Table 1 shows these conditions.

[0015]

[Table 1]

EXAMPLE 2 70 g of zinc nitrate hexahydrate, zirconium nitrate dihydrate 3
5 g and distilled water (100 g) were placed in a mixing vessel and stirred and mixed to obtain an adjusted aqueous solution. 50 cc of porous particles (average particle size: 1.0 mm) composed of a silica / alumina component were added to the adjusted aqueous solution, and the resulting solution was allowed to stand for 60 minutes. Subsequently, the porous particles and the adjusted aqueous solution were transferred to an eggplant-shaped flask, and heated while keeping the inside of the system under a negative pressure to evaporate water, and concentrated and dried. Next, the dried porous particles were transferred to a firing furnace and fired at 700 ° C. to obtain a desulfurizing agent. Table 1 shows these conditions.

EXAMPLE 3 70 g of zinc nitrate hexahydrate, zirconium nitrate dihydrate 7
0 g and distilled water (100 g) were placed in a mixing vessel and stirred and mixed to obtain an adjusted aqueous solution. 50 cc of porous particles (average particle size: 1.0 mm) composed of a silica / alumina component were added to the adjusted aqueous solution, and the resulting solution was allowed to stand for 60 minutes so that the porous particles were impregnated with the adjusted aqueous solution. Subsequently, the porous particles and the adjusted aqueous solution were transferred to an eggplant-shaped flask, and heated while keeping the inside of the system under a negative pressure to evaporate water, and concentrated and dried. Next, the dried porous particles were transferred to a firing furnace and fired at 700 ° C. to obtain a desulfurizing agent. Table 1 shows these conditions.

Comparative Example 1 70 g of zinc nitrate hexahydrate and 100 g of distilled water were put into a mixing vessel and mixed with stirring to obtain an adjusted aqueous solution. 50 cc of porous particles (average particle size: 1.0 mm) composed of a silica / alumina component were added to the adjusted aqueous solution, and the resulting solution was allowed to stand for 60 minutes. Subsequently, the porous particles and the adjusted aqueous solution were transferred to an eggplant-shaped flask, and heated while keeping the inside of the system under a negative pressure to evaporate water, and concentrated and dried. Then, the dried porous particles were transferred to a baking furnace and dried.
Calcination at 0 ° C. gave a desulfurizing agent. Table 1 shows these conditions.

Comparative Example 2 35 g of zinc nitrate hexahydrate and 100 g of distilled water were put into a mixing vessel and mixed with stirring to obtain an adjusted aqueous solution. 50 cc of porous particles (average particle size: 1.0 mm) composed of a silica / alumina component were added to the adjusted aqueous solution, and the resulting solution was allowed to stand for 60 minutes. Subsequently, the porous particles and the adjusted aqueous solution were transferred to an eggplant-shaped flask, and heated while keeping the inside of the system under a negative pressure to evaporate water, and concentrated and dried. Then, the dried porous particles were transferred to a baking furnace and dried.
Calcination at 0 ° C. gave a desulfurizing agent. Table 1 shows these conditions.

Next, evaluation of the desulfurizing agent obtained in Examples 1 to 3 and Comparative Examples 1 and 2 will be described. Among the future coal-fired power generation systems, Integrated Coal Gasification Combined Cycle (IGCC)
Is regarded as the most important as high-efficiency power generation. However, desulfurization must be performed with the gas in a high-temperature state before the gas turbine inlet due to problems such as corrosion of the gas turbine. Therefore, as an example, an IGCC configuration incorporating a moving bed gas purification system as shown in FIG. 2 is recommended, and the development of a high temperature dry desulfurization agent used in a moving bed gas purification flow chart as shown in FIG. 3 is required. As shown in FIG.
The gasified gas gasified in the coal gasifier 10 heats feed water in the heat exchanger 12 to generate steam. Heat exchanger 1
After a large portion of the char is collected, the gas from the fuel cell 2 is introduced into the moving bed gas purifier 14, desulfurized and dedusted, and then introduced into the gas turbine 16, where it is combusted by the combustor and the combustion exhaust gas is used for turbine. Rotates to generate electricity. 18 is a heat recovery boiler, and 19 is a steam turbine.

FIG. 3 shows the details of the moving bed gas purifier 14 shown in FIG. 2, and shows a moving bed gas purifier 20 for desulfurizing and dedusting the coal gasified gas from the heat exchanger 12.
In addition, a regenerating unit such as a regenerator 22 and a dust filter 24 is provided. In the case of an oxygen-blown, dry-coal feed coal gasifier, which can provide high thermal efficiency as a coal gasifier, the gas condition of the coal gasified gas is extremely low, and the gas condition is very low. When the used Zn-Fe desulfurizing agent is used, carbon deposition becomes a problem. The desulfurizing agent of the present invention includes (1) a desulfurizing agent having mechanical strength usable in a moving bed system, (2) a desulfurizing agent which does not cause carbon precipitation under a condition of extremely low moisture, and (3) an IGCC system. 343 ° C. (650 ° F.) to 538 ° C. (1000 ° C.)
(F) a desulfurizing agent that can be used in the temperature range of (° F), and (4) a desulfurizing agent having better performance than conventional desulfurizing agents. The dry desulfurizing agent of the present invention can be used in a fixed-bed desulfurization device and a fluidized-bed desulfurization device in addition to a moving-bed simultaneous desulfurization / dust removal device as shown in FIGS.

FIG. 4 shows a test apparatus used for desulfurization evaluation.
The desulfurization test conditions were as shown in Table 2.

[0023]

[Table 2]

The procedure of a desulfurizing agent evaluation test performed using the test apparatus shown in FIG. 4 will be described with reference to Table 2. First, the reactor 30 was charged with 15 ml of a desulfurizing agent. The temperature in the desulfurizing agent layer 34 was set to 425 ° C.
Temperature was reached. When the desulfurizing agent layer 34 was heated, the gas flow rate and the composition at the inlet of the reactor 30 were adjusted through the bypass line 36. The flow rate adjustment is performed by the thermal mass flow controller 38, and the gas composition analysis is performed by gas chromatography (TCD,
FPD). After confirming that the temperature inside the desulfurizing agent layer 34, the inlet gas flow rate, and the composition were under the predetermined conditions shown in Table 2, gas passing through the desulfurizing agent layer 34 was started. After passing the gas, the outlet gas was sampled at intervals of 10 minutes and analyzed by gas chromatography (TCD, FPD).
In addition, 40 is a heater coil, 42 is a thermometer, 44 is a temperature instruction controller, and 46 is a pressure control valve.

The results of the desulfurization evaluation test are shown in FIGS.
FIG. 5 shows the desulfurization curves for the five desulfurizing agents of Examples 1 to 3 and Comparative Examples 1 and 2. The desulfurization performance was improved when zirconium oxide was added than when only zinc oxide was supported. You can see that it is. The outlet sulfur concentration after desulfurization showed a very low value of 3 ppm or less, and high desulfurization performance was confirmed. In FIG. 6, 80 pp in FIG.
The value obtained by dividing the time required to exceed the outlet sulfur concentration of m 2 with respect to the zinc content as the main component of desulfurization was defined as breakthrough time, and a comparison was made. Table 3 shows the results. FIG. 6 shows that the addition of zirconia by the catalyst preparation method of the present invention significantly extends the breakthrough time. Further, under pressure (10 atm absolute pressure), further improvement in performance was confirmed.

[0026]

[Table 3]

[0027]

As described above, the present invention has the following effects. (1) Although the content of zinc oxide, which is a main component of desulfurization, and the strength of the desulfurization agent itself were insufficient with the conventional desulfurization agent, zirconium oxide (zinc oxide ( By using (zirconia), the zinc oxide content in the desulfurizing agent is increased, and sufficient strength can be obtained by using a ceramic porous body such as mullite, silica / alumina, or zirconia as the carrier. In addition, the reactivity can be improved by increasing the dispersing effect of zinc oxide. (2) In the case of a conventional desulfurizing agent in which titania is mixed with zinc oxide, a Zn—Ti bond is formed and mechanical strength increases, but reactivity decreases. Although the reaction temperature must be kept high to compensate for the drawback, the desulfurizing agent of the present invention uses a porous material such as mullite, silica / alumina, zirconia, etc., which has a mechanical strength as described above. By carrying zinc oxide on the surface, mechanical strength can be obtained. At the same time, high desulfurization performance can be obtained even at a relatively low temperature range of about 400 ° C. by confining zinc oxide in a desulfurizing agent without forming a Zn—Ti bond. (3) The zinc oxide content in the desulfurizing agent is limited by simply supporting the zinc oxide on a porous carrier such as mullite, silica / alumina, zirconia, etc. Hydrate, zirconium sulfate hydrate or zirconium chloride hydrate, as described above, increases the zinc oxide content in the desulfurizing agent, and at the same time, improves the dispersibility of the zinc oxide in the carrier, The desulfurization performance can be improved without adverse effects. (4) By the effects of the above (1) to (3), hydrogen sulfide and the like can be efficiently removed from a sulfur-containing gas containing a sulfur compound such as hydrogen sulfide generated in coal gasification gas, Further, it is possible to provide a desulfurizing agent which is easily regenerated and does not cause a decrease in durability due to carbon deposition or the like.

[Brief description of the drawings]

FIG. 1 is a process explanatory diagram showing an example of a method for producing a dry desulfurizing agent according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram of an integrated coal gasification combined cycle (IGCC) incorporating a moving bed gas purification system that can use the dry desulfurizing agent of the present invention as a desulfurizing and dust removing agent.

FIG. 3 is a systematic configuration diagram showing a detailed flow of the moving bed gas purification system in FIG. 2;

FIG. 4 is a systematic configuration diagram of a test apparatus used for a desulfurization evaluation test.

FIG. 5 is a graph showing a desulfurization curve when an evaluation test is performed on the desulfurizing agents obtained in Examples and Comparative Examples.

FIG. 6 is a graph showing a comparison of desulfurization performance when evaluation tests of desulfurizing agents obtained in Examples and Comparative Examples are performed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Coal gasifier 12 Heat exchanger 14 Moving bed gas purifier 16 Gas turbine 18 Heat recovery boiler 19 Steam turbine 20 Moving bed gas purifier 22 Regenerator 24 Dust filter 30 Reactor 32 Electric furnace 34 Desulfurizer layer 36 Bypass Line 38 Thermal mass flow controller 40 Heater coil 42 Thermometer 44 Temperature indicating controller 46 Pressure control valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kakei Hata 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Akashi Plant (72) Inventor Kimihiro Funabashi 3-chome, Higashi-Kawasakicho, Chuo-ku, Kobe-shi No. 1-1 Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Noriaki Izumi 3-1-1, Higashikawasaki-cho, Chuo-ku, Kobe City Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Kenji Kamei Hamamatsucho, Minato-ku, Tokyo 2-4-1 Kawasaki Heavy Industries, Ltd. Tokyo head office (72) Inventor Hitoshi Terada 4-1 Egasaki-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Tokyo Electric Power Company (56) References JP-A-8-266851 (JP, A) JP-A-2-99137 (JP, A)

Claims (17)

(57) [Claims] 1. A dry desulfurizing agent characterized by adding zirconium to zinc to increase the amount of supported zinc and improve dispersibility. 2. A dry desulfurizing agent comprising zinc oxide and zirconium oxide supported on porous particles of ceramic such as silica-alumina, mullite or zirconia. 3. The dry desulfurizing agent according to claim 1, wherein the dry desulfurizing agent is a dry desulfurizing agent for removing a sulfur content in a reducing gas such as a coal gasification gas. 4. A ceramic porous body such as silica / alumina, mullite or zirconia as a carrier, a solution of at least one of zinc nitrate, zinc sulfate and zinc chloride, and at least one of zirconium nitrate, zirconium sulfate and zirconium chloride. A method for producing a dry desulfurizing agent, characterized by impregnating and firing a solution of the above. 5. A method for producing a dry desulfurizing agent, comprising kneading ceramic powder such as silica / alumina, mullite or zirconia with zinc and zirconium, forming the mixture into particles or a honeycomb, and firing. 6. A zinc-containing solution and a zirconium-containing solution are mixed to form an adjusted aqueous solution, and porous particles made of ceramics such as silica-alumina, mullite or zirconia are deposited and left in the adjusted aqueous solution. The porous particles are impregnated with the adjusted aqueous solution, and then the adjusted aqueous solution containing the porous particles impregnated with the adjusted aqueous solution is heated, evaporated, concentrated and dried to support the zinc compound and the zirconium compound on the porous particles. A method for producing a dry desulfurizing agent, comprising firing porous particles carrying a zinc compound and a zirconium compound. 7. An adjusted aqueous solution obtained by mixing at least one of zinc nitrate, zinc sulfate, and zinc chloride with at least one of zirconium nitrate, zirconium sulfate, and zirconium chloride to form an aqueous solution. Porous particles made of ceramics such as alumina, mullite or zirconia are deposited and left to impregnate the adjusted aqueous solution into the porous particles, and then the adjusted aqueous solution containing the porous particles impregnated with the adjusted aqueous solution is heated to evaporate and concentrate. A method for producing a dry desulfurizing agent, comprising: drying to allow a zinc compound and a zirconium compound to be supported on porous particles; and then calcining the porous particles supporting the zinc compound and the zirconium compound. 8. The method for producing a dry desulfurizing agent according to claim 4, wherein after firing, the metal compound attached to the surface is scraped off. 9. A stirring / mixing means for stirring / mixing a zinc-containing solution and a zirconium-containing solution into an adjusted aqueous solution, and a porosity comprising a carrier such as silica, alumina, mullite or zirconia as a carrier in the adjusted aqueous solution. To deposit and leave the porous particles to impregnate the porous particles with the prepared aqueous solution, and to heat and evaporate, concentrate and dry the prepared aqueous solution containing the porous particles impregnated with the prepared aqueous solution with zinc. A heating / evaporating / concentrating / drying means for supporting the compound and the zirconium compound on the porous particles; and a firing furnace for firing the porous particles supporting the zinc compound and the zirconium compound. Dry desulfurizing agent manufacturing equipment. 10. The apparatus for producing a dry desulfurizing agent according to claim 9, further comprising a surface scraping means for scraping off a metal compound attached to the surface of the fired product. 11. A method for using a dry desulfurizing agent, comprising using the dry desulfurizing agent according to claim 1, 2, or 3 in a moving bed type dry gas purifier capable of simultaneously performing desulfurization and dust removal. 12. A method of using a dry desulfurizing agent, comprising using the dry desulfurizing agent according to claim 1, 2 or 3 in a fixed bed desulfurization apparatus. 13. A method for using a dry desulfurizing agent, comprising using the dry desulfurizing agent according to claim 1, 2 or 3 in a fluidized bed desulfurization apparatus. 14. The use of a dry desulfurizing agent according to claim 11, wherein the desulfurizing agent is used for desulfurizing a reducing gas such as a coal gasification gas. 15. An apparatus for using a dry desulfurization agent, comprising a moving bed simultaneous desulfurization / dust removal device using the dry desulfurization agent according to claim 1, 2 or 3 as a desulfurization / dust removal agent. 16. An apparatus for using a dry desulfurization agent, comprising a fixed bed desulfurization apparatus using the dry desulfurization agent according to claim 1, 2 or 3 as a desulfurization agent. 17. An apparatus for using a dry desulfurizing agent, comprising a fluidized bed desulfurization apparatus using the dry desulfurizing agent according to claim 1, 2 or 3 as a desulfurizing agent.