JPS6232970B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Application of the Invention) The present invention relates to an adsorbent for sulfur compounds in tail gas discharged from a Claus sulfur recovery device. (Background of the Invention) Currently, a Claus furnace is used as a method for recovering sulfur from a large amount of hydrogen sulfide-containing gas. The Claus reaction is a partial oxidation reaction of hydrogen sulfide, and is generally expressed by the following three equations. H ₂ S + 3/2O ₂ = SO ₂ + H ₂ O (1) 2H ₂ S + SO ₂ = 3/XSx + 2H ₂ O (2) (1) + (2) H ₂ S + 1/2O ₂ = 1/XSx + H ₂ O (3) The Claus reaction is an exothermic reaction as a whole (reaction (3))
Therefore, the lower the reaction temperature, the higher the sulfur recovery rate based on chemical equilibrium. In a Claus sulfur recovery device, the reaction is usually carried out in two or three stages, with a cooling step and a sulfur condensation step occurring in the middle. however,
Even when the Claus reaction is carried out in 2 to 3 stages, the Claus tail gas contains 2 to _0.2 % H2S, 1 to 0.1%
% _SO2 , and small amounts of _CS2 , COS, and sulfur vapors. Emission of these sulfur compounds into the atmosphere is naturally undesirable because it causes air pollution. Therefore, there is a need for a cloud tail gas processing device. Several methods for treating cloud tail gas have already been industrialized or proposed. The representative ones among them are as follows. 1. Low-temperature Claus method: A method in which the Claus reaction is carried out at a low temperature below the dew point of sulfur to increase the sulfur removal rate. This method includes a method using alumina (Special Publication No. 48-20999) and a method using activated carbon (Special Publication No. 48-20999).
46-22728) is known. In this method, since the reaction (2) is governed by chemical equilibrium, there is a limit to the sulfur removal rate, and since carbon disulfide and carbonyl sulfide cannot be removed, the overall removal rate of sulfur compounds is low. Therefore, this method is not suitable if a high sulfur removal rate is desired. Apart from the above-mentioned method, a method of carrying out a low-temperature Claus reaction in a liquid phase has also been proposed (e.g., Japanese Patent Application Laid-open No. 11361-1983). 2. Oxidation absorption method: Sulfur compounds in the tail gas are oxidized to substantially all sulfur dioxide, and the sulfur dioxide is treated by various known flue gas desulfurization methods. These methods include fixing sulfur dioxide as gypsum and absorbing it with sodium sulfite (Wellman-Lord method), but both have problems with wastewater treatment and require complicated equipment. 3. Reduction method: The sulfur compounds in the tail gas are reduced to essentially all hydrogen sulfide, and the hydrogen sulfide is treated by partial oxidation, absorption method, etc. The most famous of these are the Bevon Process (Japanese Patent Publication No. 49-11142), which uses a strain food method to treat hydrogen sulfide, and the Scotto Process (Japanese Patent Publication No. 49-114579, 47), which absorbs hydrogen sulfide using a renewable amine solution. -2908). These methods also have the same problem of waste liquid treatment as in case (2), and since the oxidation or absorption process is performed with a low-temperature solution, the gas must be cooled and water must be removed, which requires equipment. It becomes complicated and expensive. As a result of searching for a renewable solid adsorbent for hydrogen sulfide, the present inventors discovered an adsorbent containing molybdenum oxide as the main active component, preferably an adsorbent containing titanium and molybdenum oxides as the main component (adsorbent). (It can also be called a catalyst because the agent component reacts with hydrogen sulfide to form sulfide) has excellent hydrogen sulfide adsorption performance.
We also found that sulfurized adsorbents can be easily regenerated with oxygen-containing gas. The present inventors have also experimentally confirmed that by applying this adsorbent to the treatment of cloud tail gas, a safe dry process with a high desulfurization rate and relatively simple equipment can be assembled, and the present invention reached. An object of the present invention is to provide an adsorbent (catalyst) that adsorbs hydrogen sulfide from a hydrogen sulfide-containing gas such as cloud tail gas or its processed gas. The hydrogen sulfide adsorbent of the present invention is suitably used for tail gas treatment of sulfur recovery equipment, but can also be used to remove hydrogen sulfide from other hydrogen sulfide-containing gases. Hereinafter, a case where the present invention is applied to a cloud tail gas treatment method will be described. The method for recovering sulfur from cloud tail gas involves a reduction process in which the tail gas is brought into contact with a catalyst together with a hydrogen-containing reducing gas to convert the sulfur compounds in the tail gas into hydrogen sulfide, and the hydrogen sulfide-containing gas is converted to molybdenum oxide as an active ingredient. It consists of an adsorption step in which hydrogen sulfide is removed as molybdenum sulfide by bringing it into contact with the adsorbent (catalyst) of the present invention, and a regeneration step in which the adsorbent is oxidized with an oxygen-containing gas. This method essentially belongs to the above-mentioned reduction method 3. The adsorbent of the present invention and the process using the adsorbent have the following advantages compared to known adsorbents. (1) Hydrogen sulfide generated in the reduction process is adsorbed and removed using a renewable solid adsorbent (catalyst), making the entire process a completely dry process. Therefore, there is no problem with waste liquid treatment. (2) Since the hydrogen sulfide adsorption removal step is performed at a temperature of 100 to 300°C, there is no need to remove moisture in the tail gas between the reduction step and the adsorption removal step. In the conventional liquid phase partial oxidation method or amine absorption method, the reaction temperature is below the dew point of the water in the tail gas, so it is necessary to remove the water in advance. (3) The adsorbent (catalyst) that adsorbs sulfur can be easily regenerated with oxygen-containing gas, and the process can be made into a closed system by circulating the desorption gas containing a relatively high concentration of sulfur dioxide to the Claus reactor. I can do it. In order to convert the sulfur compounds in the cloud tail gas into hydrogen sulfide, a hydrogen-containing reducing gas is added to the tail gas and brought into contact with a catalyst. As this catalyst, a catalyst containing a group metal and/or a sulfide can be used. A typical example is Co-
Mo-alumina and Ni-Mo-alumina catalysts.
These catalysts are usually obtained in the form of oxides, but prior to use in the above reduction step, they may be reduced with hydrogen at 350 to 550°C to convert the active ingredients into a metal state.
Alternatively, when it is further sulfurized with hydrogen sulfide to form a sulfide, it becomes highly active in reducing sulfur compounds (mainly sulfur dioxide). The temperature at which the reduction step is performed is preferably 200 to 400°C in order to maintain catalyst activity and avoid thermal loss. When the reduction process is carried out under such reaction conditions, the hydrolysis reactions (6) and (7) of carbonyl sulfide and carbon disulfide proceed simultaneously with the reduction reactions (4) and (5) between sulfur dioxide and sulfur. . SO ₂ +3H ₂ =H ₂ S+2H ₂ O (4) 1/XSx(gas)+H ₂ =H ₂ S (5) COS+H ₂ O=CO ₂ +H ₂ S (6) CS ₂ +2H ₂ O=CO ₂ +2H ₂ S (7) Cloud tail gas contains a large amount of water, so there is no need to add the water required for reactions (6) and (7). Hydrogen required for reactions (4) and (5) must be supplied, but the amount supplied is 1 to 4 times the stoichiometric ratio. The space velocity (in terms of standard conditions) when performing the reduction step is preferably 200 to 10,000 h ^-1 , particularly preferably 200 to 5,000 h ^-1 from the viewpoint of economical catalyst usage and reactivity. Through the above reduction step, substantially all of the sulfur compounds in the tail gas are converted to hydrogen sulfide. This hydrogen sulfide-containing gas is an adsorbent (catalyst) of the present invention having molybdenum oxide as its active component, preferably at least one of tin, silicon, zirconium, and titanium oxides and molybdenum oxide as its active component. The hydrogen sulfide is adsorbed and removed by contacting with an adsorbent (catalyst) containing, most preferably, oxides of titanium and molybdenum as main components. This adsorption process is performed by reacting hydrogen sulfide with molybdenum oxide to produce molybdenum sulfide and water, and is not a normal adsorption (physical) but a reactive adsorption. Although the reaction mechanism of this adsorption step has not been fully clarified so far, it is thought to be expressed by the following formula. _3H2S + _MoO3 = _MoS3 + _3H2O (8) _2H2S + _MoO2 = _MoS2 +2H2O (9) _nH2S + _MoO3 = _{MoO3 -} nSn+ _nH2O (10) (0<n<3) In the present invention Hydrogen sulfide adsorbent (catalyst) is
As mentioned above, molybdenum oxide is the main active ingredient. The active ingredient molybdenum oxide is usually combined with other ceramic materials such as alumina, silica, silica-alumina, zeolite, diatomaceous earth,
Molybdenum oxide is used as a mixture with magnesia, zirconia, tin oxide, titania, etc., or as supported on the above ceramic material. Among the above-mentioned ceramic materials, tin oxide, silica, zirconia, and titania are excellent as carriers for molybdenum oxide or as materials that improve adsorption performance. It is superior in terms of both hydrogen sulfide adsorption performance and oxidative regeneration activity. The most preferred material to be mixed with molybdenum oxide or to support molybdenum oxide is titania. Adsorbents whose main components are titanium and molybdenum oxides not only have excellent hydrogen sulfide adsorption performance and activity in the oxidation regeneration process, but also have extremely excellent durability. Therefore, in the following explanation,
The description will focus on TiO ₂ and MoO ₃ adsorbents. However, the TiO ₂ MoO ₃ adsorbent TiO ₂ SnO ₂ , SiO ₂ ZrO ₂
It goes without saying that it may also be replaced with a mixture thereof including TiO ₂ . The temperature at which the adsorption step of the present invention is carried out is preferably 100 to 300°C, particularly 120 to 300°C, from the viewpoint of adsorption rate and amount of adsorption.
250°C is preferred. If the temperature is too high, the oxidation activity of the adsorbent increases, reactions that produce sulfur dioxide occur simultaneously, and the desulfurization rate tends to decrease. As mentioned above, the reduction step of the present process preferably ranges from 200 to
400℃, since the adsorption process is carried out at 100-300℃.
There is no need for a cooling step between the reduction step and the adsorption step, or even if it is necessary, there is no need to lower the temperature below the dew point of the water in the tail gas. In the conventionally known wet method for removing hydrogen sulfide, it is necessary to remove moisture from the tail gas.
A large cooling tower was required. The space velocity (in terms of standard conditions) of the gas to be treated when performing the adsorption step is preferably 100 to 10,000 h ^-2 , particularly preferably 100 to 5,000 h ^-1 from the viewpoint of the amount of adsorbent used and adsorption properties. The upper limit of space velocity is
Although it depends on the concentration of hydrogen sulfide in the gas to be treated,
For example, if the hydrogen sulfide concentration is 1%, approximately
10000h ^-1 . The higher the concentration of hydrogen sulfide, the lower the upper limit of space velocity. In practice, the upper limit of the space velocity can be determined by selecting the time required for the adsorbent to reach saturated adsorption, or by selecting an appropriate time required for the adsorption step-regeneration step cycle. When purifying cloud tail gas using the catalyst of the present invention, the types of adsorption towers include fixed bed,
Both moving beds and fluidized beds can be used. In the case of a fixed bed, it is preferable to use at least two adsorption towers (or reaction towers) filled with the adsorbent of the present invention to carry out the reaction continuously. For example, if two adsorption towers are installed, one may be used for the adsorption process and the other for the regeneration process. Regeneration of the adsorbent (catalyst), which is at least partially sulfurized by reactive adsorption of hydrogen sulfide, can be easily performed using an oxygen-containing gas. Nitrogen dioxide, ozone, etc. can also be used, but in practice it is appropriate to use air or oxygen. When the sulfurized adsorbent is brought into contact with an oxygen-containing gas, the sulfide in the adsorbent becomes an oxide, and the sulfur is desorbed as sulfur dioxide. As mentioned earlier, the sulfurized form of the adsorbent is not necessarily clear, but reaction equations (8), (9),
(10), it can be estimated that the reaction in the regeneration process will be as follows. MoS ₃ +9/2O ₂ =3SO ₂ +MoO ₃ (11) MoS ₂ +3O ₂ =2SO ₂ +MoO ₂ (12) (MoS ₂ +7/2O ₂ =2SO ₂ +MoSO ₃ ) MoO ₃ -nSn+3n/2O ₂ =nSO ₂ +MoO ₃ (13) The desorption gas in the regeneration process is a gas containing sulfur dioxide. For example, if air is used as the regeneration gas, the desorption gas will contain about 14% sulfur dioxide, and if pure oxygen is used as the regeneration gas, the desorption gas will be nearly pure sulfur dioxide. Although the desorption gas naturally contains a small amount of unreacted oxygen, the oxygen concentration in the desorption gas can be made extremely low by appropriately selecting the temperature and space velocity in the regeneration step.
The desorption gas contains a high concentration of sulfur dioxide as mentioned above, but this desorption gas can be used as a raw material for sulfuric acid production, or it can be treated with a known flue gas desulfurization method (for example, a method of recovering it as gypsum). You may. However, the most preferred method is to circulate the desorption gas to a Claus furnace. By circulating, the Claus reactor tail gas purification method of the present invention is completely closed. The temperature when performing the regeneration step is preferably 100 to 600°C from the viewpoint of the oxidation rate and adsorption capacity of the adsorbent. If the regeneration temperature is too high, the adsorption performance may deteriorate due to evaporation of molybdenum oxides or sulfides, which are adsorbent components, and sintering of the adsorbent. The reactions in the regeneration process are thought to be expressed by equations (11), (12), and (13), and each of these reactions has a
It can be estimated that this is an exothermic reaction of 110 kcal. Therefore, if, for example, air is used as the regeneration gas, the heat of reaction will cause the desorption gas to reach an extremely high temperature of far exceeding 1000°C (assuming an adiabatic reaction without considering the temperature rise of the adsorbent). used in the present invention
When TiO ₂ MoO ₃ adsorbent is exposed to high temperatures of 600°C or higher, its adsorption performance decreases. Therefore, the oxygen concentration in the regeneration gas must be selected such that the temperature of the desorption gas is below 600°C. To obtain a desorption gas with a low oxygen concentration, air, pure oxygen gas, etc. may be diluted with an inert gas, or a preferable method is to circulate or mix a desorption gas containing sulfur dioxide into the regeneration gas. . According to the latter method, a desorption gas containing a high concentration of sulfur dioxide is obtained, and by circulating this desorption gas to the Claus reactor as described above, the tail gas purification apparatus of the present invention can be closed. The supply rate of the regeneration gas in the regeneration process, that is, the space velocity, is about the same as that in the adsorption process to 2.
It is sufficient if it is ~3 times. Under such conditions, the sulfides in the adsorbent can be almost completely converted to oxides.
Since the oxidation activity of the adsorbent (catalyst) of the present invention is extremely high, all sulfur components are quickly desorbed as sulfur dioxide. The ratio of titanium to molybdenum in the adsorbent of the present invention is preferably Ti:Mo in atomic ratio of 99:1 to 30:70, particularly 98:2 to 50: A range of 50 is preferred. Among the adsorbent components of the present invention, the reaction formula (8),
It is thought that molybdenum oxide is directly involved in the reactive adsorption of hydrogen sulfide as shown in (9) and (10). However, in this case, the role of titanium oxide is not only as a mere carrier, but also as an active ingredient. This can be inferred from the following. That is, using alumina, which is commonly used as an adsorbent carrier,
When producing Al ₂ O ₃ - MoO ₃ adsorbent, the present invention
Compared to TiO ₂ -MoO ₃ adsorbents, it has inferior hydrogen sulfide adsorption performance and requires higher temperatures in the regeneration process. As described above, titanium oxide, tin oxide, silica,
The role of zirconia is not only as a carrier, but also to improve the reaction adsorption activity of molybdenum oxide against hydrogen sulfide, and to improve the activity when oxidizing sulfurized molybdenum. It is considered a thing. Another important role of titanium oxide is to significantly increase the lifetime of the sorbent of the present invention. That is, even in an atmosphere where sulfur dioxide and oxygen coexist in the regeneration process, the adsorbent component does not become sulfated. For example, if a molybdenum adsorbent supported on alumina is exposed to an atmosphere in which sulfur dioxide and oxygen coexist, sulfation of the alumina progresses, resulting in a decrease in the performance of the adsorbent. On the other hand, since titanium oxide hardly generates sulfate, the adsorbent of the present invention maintains its performance for a long time. As described above, the present invention can provide an adsorbent that has excellent reaction and adsorption performance for hydrogen sulfide and has good durability. Here, the manner in which the adsorbent of the present invention is used will be shown with one example. FIG. 1 is a schematic diagram of purifying cloud tail gas using the adsorbent of the present invention. In the figure, a case will be described in which the adsorption tower 3 is currently in the adsorption process and the adsorption tower 4 is in the regeneration process. In this case, valves 12, 14, 15, and 18 are open, and valves 11, 13, 16, and 17 are closed. The tail gas discharged from the sulfur recovery device 1 passes through a pipe 20, is added with hydrogen, and is led to the reduction reactor 2. In the reduction reactor 2, substantially all of the sulfur compounds in the tail gas are converted to hydrogen sulfide. The gas leaving the reduction reactor 2 is cooled by a heat exchanger 5, passes through a valve 12, enters an adsorption tower 3, and hydrogen sulfide in the gas is removed by an adsorbent containing molybdenum oxide. The gas leaving adsorption tower 3 passes through valve 1.
5. It is discharged to the atmosphere from the chimney 10 through the pipe 21. On the other hand, gas containing oxygen, sulfur dioxide, and nitrogen is supplied to the adsorption tower 4 through a valve 14 by pumps 8 and 7. The sulfurized form of the adsorbent is oxidized by oxygen in the regeneration gas, releasing sulfur dioxide. The desorbed gas at the outlet of the adsorption tower 4 passes through a valve 18 and is cooled by a heat exchanger 6. A part of the desorbed gas passes through the pipe 24 and is pumped by the pump 9.
It is circulated to the sulfur recovery device 1 through the pipe 25. The other part of the desorption gas passes through the pipe 23 and is mixed by the pump 7 with air (delivered by the pump 8) to become regeneration gas and circulated to the desorption tower 4. The oxygen concentration of the regeneration gas is determined by adjusting the flow rates of pumps 7 and 8. Normally, the time required for the regeneration process is shorter than the time for the adsorption process, so when the desorption of sulfur dioxide is completed, if you stop the pump 8, stop the air supply, and run only the pump 7, the adsorption process can be completed in a short time. The temperature of column 4 drops to a predetermined value. When the adsorption tower 3 has reached saturated adsorption and the adsorption tower 4 has been regenerated, valves 11, 13, 16, and 17 are opened, and valve 1 is opened.
2, 14, 15, and 18 are closed. By doing this, the adsorption tower 3 moves to the regeneration process, and the adsorption tower 4 moves to the adsorption process. By switching the valves as described above, the Claus furnace tail gas can be continuously processed. In the tail gas treatment equipment shown in Figure 1, the chimney 1
An incinerator or catalytic oxidation device is installed before the adsorption tower 3 or 4 to oxidize trace amounts of sulfur compounds (hydrogen sulfide, carbon disulfide, carbonyl sulfide, etc.) contained in the gas at the outlet of the adsorption tower 3 or 4. Using sulfur is also desirable from the standpoint of removing bad odors. (Embodiments of the Invention) Example 1 500 g of metatitanic acid slurry containing about 55% by weight of titanium oxide was taken and thoroughly mixed with 260 g of ammonium paramolybdate in a kneader. After drying the mixture at 120 to 140°C, it was ground to 20 meshes or less using a mill, and 15 g of graphite was added and mixed well. The powder of this mixture was compressed into cylindrical tablets with a height of 6 mm and a diameter of 6 mm using a tablet machine. The obtained molded product was fired in an electric furnace at 500°C for 3 hours. This adsorbent contains Ti and Mo in an atomic ratio of 7:3. Examples 2, 3, 4 Ti:Mo=9:1, 8:
A 2.5:5 (atomic ratio) adsorbent was prepared. Adsorbent of Example-2 Ti-Mo (9:1) 〃 3 〃 Ti-Mo (8:2) 〃 4 〃 Ti-Mo (5:5) Examples 5, 6 1000g of titanium tetrachloride in 2000ml of water It gradually dissolved. Aqueous ammonia was added dropwise to this solution to form a precipitate of orthotitanic acid. This precipitate was thoroughly washed with decantation and passed through the mouth. The cake-like precipitate was dried at 120-140°C, pulverized, and further calcined at 500°C for 1 hour. The obtained fired product was pulverized to 50 mesh or less. This fine powder was molded into a spherical shape of 3 to 5 mm using a rolling granulator. The obtained molded article was fired at 550°C for 2 hours to obtain a titanium oxide carrier. The obtained titanium oxide carrier was impregnated with paramolybdic acid solutions of various concentrations to obtain adsorbents having the following compositions. Adsorbent of Example-5 Ti-Mo (Mo: 8wt%) Adsorbent of Example-6 Ti-Mo (Mo: 13wt%) Example 7 In this example, an experiment was conducted in which a reduction process and an adsorption process were performed. Show the results. The experimental equipment used is as follows. Two reaction tubes heated from the outside in an electric furnace were connected in series. Each reaction tube has an inner diameter of 27 mm, a length of 600 mm, and is filled with a catalyst or adsorbent in the center. The reaction tube on the upstream side through which the reaction gas flows was used as a reduction reactor, and the reaction tube on the downstream side was used as an adsorption reactor. The gas leaving the reduction reactor either enters the adsorption reactor or bypasses it and is led to an analyzer (gas chromatograph). Furthermore, oxygen-containing gas (regeneration gas) can be introduced into the adsorption reactor from before the adsorption reactor. The reduction reactor was filled with 40 ml of Comox, a commercially available hydrodesulfurization catalyst, pulverized into 10 to 20 mesh pieces. Prior to use, the reduction catalyst was reduced with hydrogen at 500°C and sulfided with hydrogen sulfide. In the adsorption reactor, 80ml of the adsorbent shown in Example-1 was crushed into 10 to 20 meshes.
filled with. The reaction conditions of the reduction and adsorption reactor are as follows. Reduction reactor Temperature: 350°C Space velocity: 1000h ^-1 Catalyst Co-Mo-Alumina adsorption reactor Temperature: 150°C Space velocity: 500h ^-1 Adsorbent TiO ₂・MoO ₃ (Example-1) The following reaction gases are used: _{Using a gas with a composition of}
When the temperature was below, nitrogen gas containing 3% oxygen was passed through the adsorption reactor to regenerate the catalyst. The TiO ₂ ·MoO ₃ adsorbent of the present invention has improved H ₂ S adsorption performance at the initial stage of use. Therefore, the ring element-adsorption step and regeneration step were repeated at least three times. The experimental results obtained are shown in Table 1. Note that the desorption gas in the regeneration process contained about 2% sulfur dioxide. Example 8 Same as Example 8, except that the catalyst packed in the reduction reactor was a commercially available Nimox catalyst for hydrodesulfurization, and the adsorbent of Example 2, 3, or 4 was used in the adsorption reactor. An experiment was conducted in the same manner as in Example 7, and the results shown in Table 1 were obtained.

[Table] Example 9 Example except that the temperature of the reduction reactor was 300°C, the temperature of the adsorption reactor was 120, 150, 200, 250, and 300°C, and the adsorbent shown in Example-5 was used. An experiment was conducted in the same manner as in 7-7, and the results shown in Table 2 were obtained. When the adsorbent was regenerated at the same temperature as adsorption, it was confirmed that sulfur dioxide was desorbed at any temperature.

【table】

[Table] Example 10 80% of the adsorbent shown in Example-6 was added to the adsorption reactor.
The experiment was conducted in the same manner as in Example 7, except that 40 or 20 ml was filled, and the results shown in Table 3 were obtained.

[Table] Example 11 An experiment similar to Example 7 was conducted using a material containing 100% titanium oxide, which does not contain molybdenum oxide, as an adsorbent for hydrogen sulfide. Exit gas is always
It contained about 2% HS. In other words, titanium oxide alone does not have the ability to adsorb HS. Example 12 An adsorbent containing molybdenum, tin, and titanium oxides in an atomic ratio of approximately 8:40:52 was prepared using metastannic acid, metatitanic acid, and ammonium molybdate as raw materials. When a test was conducted using this adsorbent under the same conditions as in Example 9 (however, the adsorption temperature was 150°C), the outlet gas composition was almost the same, but the time required for the desulfurization rate to fall below 95% was It was 60 minutes.

[Brief explanation of the drawing]

FIG. 1 is a processing system diagram showing an example of purifying Claus reactor tail gas using the adsorbent of the present invention. 1... Sulfur recovery device, 2... Reduction reaction tower, 3, 4...
Adsorption tower, 5, 6... Heat exchanger, 7-9... Pump, 1
1-18...Valve, 20-25...Piping.

Claims (1)

[Claims] 1 Molybdenum oxide, titanium oxide, tin oxide,
An adsorbent for sulfur recovery equipment tail gas that contains at least one of silica and zirconia and adsorbs hydrogen sulfide as molybdenum sulfide. 2. Claim 1, wherein the atomic ratio of the metal components of the total amount of titanium oxide, tin oxide, silica, and zirconia to molybdenum oxide is 1:99 to 70:30.
Adsorbent for tail gas of sulfur recovery equipment as described in section. 3. The adsorbent for tail gas of a sulfur recovery equipment according to claim 1, wherein the atomic ratio of the metal component of titanium oxide to molybdenum oxide is from 2:98 to 50:50.