JP5388974B2 - Method for producing regenerated catalyst for chlorine production, method for regenerating degraded catalyst, method for producing chlorine, and method for maintaining activity of catalyst for chlorine production - Google Patents

Description

  The present invention relates to a method for producing a regenerated catalyst by regenerating a deteriorated catalyst whose activity has decreased with time in the production of chlorine by oxidizing hydrogen chloride with oxygen using a fluidized bed reactor, and the deteriorated catalyst. , A method for producing chlorine efficiently and economically while regenerating the catalyst, and a method for maintaining the flow stability and reaction activity of the catalyst in the fluidized bed reactor for a long time About.

Chlorine is useful as a raw material for vinyl chloride, phosgene and the like. As a method for industrially producing chlorine, catalytic oxidation of hydrogen chloride is widely known.
Production by catalytic oxidation of hydrogen chloride was devised as one of the methods for recovering hydrogen chloride by-produced when producing vinyl chloride monomers and isocyanates. Since hydrogen chloride produced as a byproduct is used as a raw material, it is a very effective process from the viewpoint of environmental impact.

  There are three types of production of chlorine from hydrogen chloride by catalytic oxidation of hydrogen chloride: electrolysis, gas phase catalytic oxidation, and non-contact oxidation. Among them, the gas phase catalytic oxidation method is also called a Deacon process, and was proposed in the 1860s as a method for obtaining chlorine from hydrogen chloride and oxygen. This reaction is an equilibrium reaction with exotherm, and the reaction proceeds more preferentially as the reaction temperature is lower. As the catalyst used in this reaction, for example, a catalyst mainly composed of copper, a catalyst mainly composed of chromium, and the like are known.

As a catalyst having copper as a main component, for example, a catalyst in which a lanthanoid such as copper chloride, alkali metal chloride or dymium chloride is supported on a silica gel carrier having a specific surface area of 200 m ² / g or more and an average pore diameter of 60 mm or more (patent) Document 1), a catalyst prepared by impregnating copper, potassium and dymium into silica gel having a specific surface area of 410 m ² / g and a pore volume of 0.72 ml / g (Patent Document 2) is known. These catalysts are composed of inexpensive components, but have low reaction activity and require high temperatures to obtain sufficient activity. Since the Deacon process is an equilibrium reaction with exotherm, there is a problem that the higher the temperature, the lower the equilibrium conversion rate of hydrogen chloride. In addition, dymium is a mixture containing various rare earth elements, but because it is a mixture, its composition is not constant depending on the mining place and timing, and the activity using the catalyst using dymium is not constant and stable use. Is disadvantageous.

  As a catalyst mainly composed of chromium, for example, a catalyst in which chromia is supported on silicon oxide is known (Patent Documents 3 and 4). Since this catalyst also has low reaction activity, it becomes a reaction at a high temperature, and there is a problem that it is difficult to obtain a sufficient equilibrium conversion rate as in the case of a catalyst mainly composed of copper. At the same time, the main component is chromium, which is problematic for health and safety, and it can be said that the problem is large from the viewpoint of environmental impact.

  The fluidized bed process is a process in which solid particles are suspended by a fluid to perform operations such as reaction and heat treatment, and has been widely known since the latter half of the 19th century. In the oxidation reaction using a hydrogen chloride catalyst, a fluidized bed process using a catalyst containing chromium as a main component has been put into practical use, although it involves the above problems. In the fluidized bed process, solid particles are required to maintain good fluidity during the reaction, and various examinations are made regarding particle physical properties, apparatus structure, and operating conditions. Also, in order to maintain good fluidity of the solid particles, it is necessary to maintain the catalyst shape during the reaction. If the shape of the catalyst changes significantly due to wear, crushing, etc. during the reaction, the catalyst components are scattered. This causes a decrease in reaction activity.

  However, there are many unknown areas regarding the influence of each factor on fluidity. Therefore, conventionally, it is difficult to reuse the catalyst used in the fluidized bed process, and the catalyst whose activity is lowered is disposed of as a waste, and there is a great problem from the viewpoint of environmental load. In addition, the cost of the produced chlorine was also a cause.

Therefore, methods for regenerating and utilizing a catalyst having a reduced activity have been proposed (for example, Patent Documents 5 to 7).
However, these regeneration methods are methods for regenerating a catalyst mainly composed of chromium, and are applied immediately because the catalyst itself is different from a catalyst composed mainly of copper and porous particles. Can not. That is, the catalyst mainly composed of chromium is mainly a composite of chromium and silica, and it is estimated that the deterioration of the activity is mainly caused by the decrease in the chromium concentration. On the other hand, the deterioration of the activity of a catalyst having copper as a main component and porous particles as a carrier is caused by a decrease in copper concentration, a ratio of copper element and alkali metal element supported on the carrier, and copper element and lanthanoid. It is conceivable that the ratio of elements changes greatly and that impurities accumulated over time work as poisoning components. Thus, since the deterioration mechanism of the catalyst is different, these regeneration methods cannot be applied immediately. Further, in the methods of Patent Documents 6 and 7, since the metal concentration in the catalyst does not change, the catalyst activity is recovered multiple times for a catalyst mainly composed of copper and porous particles as a carrier. It is unclear whether it can be done, and it is difficult to say that the original reaction activity and a high catalyst recovery rate can be realized at the same time.

  Therefore, in a fluidized bed process, a catalyst that has copper as a main component and porous particles as a carrier, which deteriorates with time, can be efficiently regenerated, and by using such a regeneration technology, it can be efficiently Therefore, there has been a demand for a method that can produce chlorine stably over a long period of time economically.

U.S. Pat. No. 3,260,678 US Pat. No. 3,483,136 JP 61-275104 A Japanese Patent No. 25133756 Japanese Patent Laid-Open No. 10-15389 JP-A-62-254846 Japanese Examined Patent Publication No. 7-67530

  The present invention provides a method and a regenerated catalyst for efficiently and economically regenerating a deteriorated catalyst whose activity has decreased over time in the production of chlorine by oxidizing hydrogen chloride with oxygen using a fluidized bed reactor. It is an object to obtain a method and a method for economically producing chlorine over a long period of time while efficiently regenerating the deteriorated catalyst. Another object of the present invention is to provide a catalyst activity maintaining method that can maintain the excellent reaction activity and high flow stability of the catalyst over a long period of time and ensure the performance of the plant for a long period of time.

  The method for producing a regenerated catalyst for chlorine production according to the present invention is a treatment step in which a deteriorated catalyst used in producing chlorine by oxidizing hydrogen chloride with oxygen is impregnated with a solution containing copper using a fluidized bed reactor. 1 or 2 or more, and the deterioration catalyst comprises (A) a copper element, (B) an alkali metal element, and (C) a lanthanoid element satisfying a bond dissociation energy with oxygen at 298K of 100 to 185 kcal / mol. The active ingredient is a catalyst supported on a porous particle carrier.

  In the regeneration method of the deteriorated catalyst of the present invention, the deteriorated catalyst is impregnated with a solution containing copper once or twice, and the deteriorated catalyst oxidizes hydrogen chloride with oxygen using a fluidized bed reactor. And (A) a copper element, (B) an alkali metal element, and (C) a lanthanoid element satisfying a bond dissociation energy with oxygen at 298K of 100 to 185 kcal / mol. The active ingredient containing is a catalyst supported on a porous particle carrier.

  The method for producing chlorine of the present invention is a method for producing chlorine by oxidizing hydrogen chloride with oxygen using a catalyst in a fluidized bed reactor, and the total catalyst contained in the fluidized bed reactor. The copper element content is 0.3 wt% or more and 4.5 wt% or less per 100 wt% of the total catalyst, and a part of the catalyst is drawn out from the outlet of the fluidized bed reactor. And a step of impregnating the obtained catalyst with a solution containing at least one or more times, and charging the obtained catalyst into a fluidized bed reactor. The extracted catalyst comprises (A) elemental copper (B) an active component containing an alkali metal element and (C) a lanthanoid element whose bond dissociation energy with oxygen at 298 K satisfies 100 to 185 kcal / mol, contains a catalyst supported on a porous particle carrier With features That.

  In the method for maintaining the activity of the catalyst for chlorine production according to the present invention, a part of the catalyst for chlorine production used when producing chlorine by oxidizing hydrogen chloride with oxygen is extracted from the outlet of the fluidized bed reactor. A method of impregnating a catalyst at least once or twice with a solution containing copper and charging the obtained catalyst into a fluidized bed reactor, maintaining the activity of the catalyst while regenerating the catalyst, The content of copper element in the total catalyst contained in the fluidized bed reactor is 0.3 wt% or more and 4.5 wt% or less per 100 wt% of the total catalyst, and the extracted catalyst is (A An active component containing a lanthanoid element satisfying a bond dissociation energy with oxygen in 100) to 185 kcal / mol supported on a porous particle carrier. Characterized in that it comprises a.

It is preferable that the solution containing copper contains a lanthanoid satisfying a bond dissociation energy with copper, an alkali metal, and oxygen at 298K of 100 to 185 kcal / mol.
The obtained regenerated catalyst preferably has a copper content higher than that of the deteriorated catalyst, more preferably 0.1% by weight or more.

Moreover, it is preferable that the average sphericity of the obtained regenerated catalyst is 0.80 or more.
It is preferable to include a treatment of dissolving and removing the active component and poisoning component contained in the deteriorated catalyst with water and / or an acidic solution before the treatment of impregnating the solution containing copper.

It is preferable to dry and / or bake after the dissolution and removal treatment.
It is preferable to dry and / or bake after the treatment of impregnating the solution containing copper.

  According to the present invention, in a reaction in which hydrogen chloride is oxidized with oxygen by using a catalyst in a fluidized bed reactor to produce chlorine, a deteriorated catalyst with reduced performance is efficiently and economically high. The initial performance of the catalyst can be restored.

  In addition, by efficiently regenerating and reusing the deteriorated catalyst, the catalyst in the fluidized bed reactor can maintain high fluidity for a long time without causing excellent high reaction activity and sticking. Can be secured. Therefore, a high chlorine yield can be obtained over a long period of time, and chlorine can be provided stably and economically.

  Furthermore, according to the present invention, the deteriorated catalyst can be reused efficiently, so that the burden on the environment can be minimized.

In FIG. 1, the schematic of the glass reaction tube used in the catalytic reaction test method of an Example, a reference example, and a comparative example is shown.

Hereinafter, the present invention will be specifically described.
<Method for producing regenerated catalyst for chlorine production, method for regenerating degraded catalyst, method for producing chlorine, and method for maintaining catalyst activity>
(Deteriorated catalyst)
The deterioration catalyst in the present invention is a catalyst used when hydrogen chloride is oxidized with oxygen in a fluidized bed reactor to produce chlorine, and (A) a copper element, (B) an alkali metal element, and (C ) A catalyst in which an active component containing a lanthanoid element satisfying a bond dissociation energy with oxygen at 298 K of 100 to 185 kcal / mol is supported on a porous particle carrier. The carrier is not particularly limited as long as it is a porous particle, can disperse and carry the active ingredient, and has corrosion resistance that does not decompose against hydrochloric acid and chlorine. , Silica alumina, alumina, titania, zirconia, glass and the like. Among them, in the present invention, the support is preferably silica or alumina, and silica is particularly preferable in that a treatment for efficiently impregnating a solution containing copper can be performed.

  In the fluidized bed reactor, the reaction activity of the catalyst in the initial stage of the reaction is reduced due to the decrease in the active component, alteration of the active component, physical destruction of the catalyst due to crushing, accumulation of poisonous components, etc. In addition, the flow stability of the catalyst deteriorates. In the present invention, such a catalyst deteriorated with time can be regenerated to a regenerated catalyst exhibiting initial catalytic activity at a high recovery rate, and it can be said that the economic effect is very large. The shape of the deteriorated catalyst is not particularly limited, but a spherical shape is preferable in that the regenerated catalyst can be efficiently recovered.

  Further, the deterioration catalyst is not limited by the chlorine yield, but it is considered that the deterioration catalyst is significantly deteriorated if the chlorine yield of the deterioration catalyst is reduced by 10% or more with respect to the initial chlorine yield. In addition, a chlorine yield can be calculated | required by the method as described in an Example.

  The copper element (A) contained in the deterioration catalyst may be contained in either a monovalent or bivalent state. The content of copper element varies depending on the degree of deterioration and is not particularly limited. However, considering the copper content in the catalyst before the initial deterioration and the environment in which the catalyst is used, 0.01% by weight per 100% by weight of the deteriorated catalyst. As described above, it is often in the range of 5.0% by weight or less. Further, considering the efficiency of the treatment of impregnating a solution containing copper, which will be described later, based on the degree of deterioration, the content of the copper element is 0.05% by weight or more and 3.0% by weight per 100% by weight of the deteriorated catalyst. % Or less, preferably 0.1% by weight or more and 1.0% by weight or less, the degree of activity improvement is greater and the regeneration effect becomes more prominent.

  Examples of the alkali metal element (B) contained in the deterioration catalyst include lithium, sodium, potassium, rubidium, cesium, and francium. These alkali metal elements (B) may be contained alone or in combination of two or more in the catalyst. Among these, the deterioration catalyst contains sodium and / or potassium from the viewpoint that the interaction between the remaining component and the copper component treated in the treatment step of impregnating the solution containing copper described later is likely to occur. Preferably, potassium is more preferable. The content of the alkali metal element (B) varies depending on the degree of deterioration and is not particularly limited. However, considering the content of the alkali metal element in the catalyst before the initial deterioration and the environment in which the catalyst is used, the deterioration catalyst is 100% by weight. In many cases, it is in the range of 0.01 wt% or more and 3.0 wt% or less. Further, considering the efficiency of the treatment of impregnating a solution containing copper, which will be described later, based on the degree of deterioration, the content of alkali metal (B) is 0.05% by weight or more per 100% by weight of the deterioration catalyst. When the content is 0.0% by weight or less, preferably 0.1% by weight or more and 1.0% by weight or less, the degree of activity improvement is greater and the regeneration effect becomes more remarkable.

  The lanthanoid element (C) contained in the deterioration catalyst is a lanthanoid element having a bond dissociation energy with oxygen at 298 K in the range of 100 to 185 kcal / mol among so-called lanthanoid elements having atomic numbers 57 to 71. Here, the bond dissociation energy of lanthanoid and oxygen at 298K is as shown in the following Table 1. Specifically, as the lanthanoid element (C) contained in the deterioration catalyst, praseodymium (Pr), neodymium ( Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm) and lutetium ( And one or more lanthanoid elements selected from the group consisting of Lu).

なお、上記表１に記載の２９８ＫでのＬｎ−Ｏ（ランタノイド−酸素）結合解離エネルギーＤ₂₉₈の値は、有機金属反応剤ハンドブック（玉尾皓平編著、化学同人、発行年月：２００３年６月）２２３頁表２に記載の値である。

Incidentally, Ln-O at 298K according to Table 1 - the value of (lanthanide oxygen) bond dissociation energy D ₂₉₈ is an organometallic reagent Handbook (Tamao Akirataira eds, Kagaku Dojin, Publication date: June 2003 ) The values described in Table 2 on page 223.

  In the present invention, if the catalyst regenerated from the deteriorated catalyst has a bond dissociation energy of the lanthanoid element exceeding 185 kcal / mol, the bond with oxygen becomes too strong, and if it is less than 100 kcal / mol, the affinity with oxygen Is too low, the reaction activity (chlorine yield) may not be sufficiently improved. Therefore, it is preferable to regenerate the deteriorated catalyst having the bond dissociation energy of the lanthanoid element within the above range because the regenerated catalyst can be recovered more efficiently. Of these lanthanoid elements, praseodymium, neodymium, samarium, europium, gadolinium, and dysprosium are preferable, and praseodymium, neodymium, samarium, and europium are more preferable. These lanthanoid elements may be contained alone or in combination of two or more.

  The content of the lanthanoid element (C) varies depending on the degree of deterioration and is not particularly limited. However, considering the content of the alkali metal element in the catalyst before the initial deterioration and the environment in which the catalyst is used, , Often in the range of 0.01 wt% or more and 5.0 wt% or less. In consideration of the efficiency of the treatment for impregnating a solution containing copper, which will be described later, based on the degree of deterioration, the content of the lanthanoid element is 0.05% by weight or more and 3.0% by weight per 100% by weight of the deteriorated catalyst. % Or less, preferably 0.1% by weight or more and 1.0% by weight or less, the degree of activity improvement is greater and the regeneration effect becomes more prominent.

(Process for impregnating the deterioration catalyst with a solution containing copper)
In the present invention, the deterioration catalyst includes a treatment step of impregnating a solution containing copper once or twice or more. By the above impregnation treatment, the active component reduced during the hydrogen chloride oxidation reaction is introduced and replenished efficiently and economically without being affected by the components remaining in the deteriorated catalyst. It becomes possible. In addition, if the present invention is used, it is possible to restore the deteriorated catalyst to a catalyst having the same performance as that of the catalyst before the start of the reaction with a recovery rate of almost 100%, and it is possible to minimize the number of discarded catalysts. Become.

  In the impregnation, if the deterioration catalyst is impregnated with a solution containing copper, the bond dissociation energy with copper, alkali metal, and oxygen at 298K is 100 to 185 kcal / s before and after the impregnation of the present invention. A solution containing a lanthanoid in the mol range may be impregnated, or a solution containing one or more of these active ingredients may be impregnated separately. Further, the deterioration catalyst may be impregnated with a plurality of active components. The number of treatments impregnated with the solution is not particularly limited, but is preferably 5 times or less, and more preferably 3 times or less. In view of the efficiency of the treatment process, when impregnating a plurality of metals, it is preferable to impregnate at the same time. In order to efficiently express the interaction of active ingredients, bond dissociation energy with copper, alkali metal and oxygen at 298K Is preferably impregnated with a solution containing a lanthanoid in the range of 100 to 185 kcal / mol, and in order to maximize the interaction of the active ingredients, any one selected from copper, potassium, praseodymium, neodymium, samarium and europium It is more preferable to impregnate a solution containing one or more kinds.

In addition, about the copper, an alkali metal, and a lanthanoid, the said deterioration catalyst can be referred.
The treatment method to be impregnated is not particularly limited, and an evaporative drying method, a spray method, an adsorption method, an equilibrium adsorption method, a pore filling method, and the like are applicable. From the viewpoint of ease of process, the evaporation to dry method or the spray method is preferable.

  When impregnating, in any method, it is necessary to add a compound or solution containing the active ingredient to an arbitrary solvent to prepare a solution containing copper in which the active ingredient is completely dissolved or thoroughly mixed. It becomes.

  In any treatment method, the temperature at the time of impregnation is not particularly limited, but is preferably 0 ° C. or higher and lower than 100 ° C., more preferably 10 ° C. or higher and lower than 50 ° C. If the temperature at the time of impregnation is less than 0 ° C., the active ingredient dissolved in the solution may be precipitated in the solvent, which may cause freezing of the solution itself, which is not preferable. On the other hand, if it is 100 ° C. or higher, the solvent in the solution may be evaporated, which is not preferable.

  The solvent used for producing the solution containing copper is not particularly limited as long as it can dissolve or disperse the compound containing the active ingredient, water, alcohol such as methanol and ethanol, organic acid such as formic acid and acetic acid, Alternatively, a mixture of these may be mentioned, but water is preferable because of easy handling. The concentration when the active ingredient is dissolved and dispersed in the solvent is not particularly limited as long as the compound of the active ingredient can be uniformly dissolved or dispersed, but if the concentration is too low, the amount of liquid used may increase. The content of the active ingredient is preferably 1 to 50% by weight, more preferably 2 to 40% by weight per 100% by weight of the total of the active ingredient and the solvent.

Further, copper is not particularly limited, but it is preferably 0.4 to 20% by weight, preferably 0.8 to 16% by weight per 100% by weight of the solvent because copper can be efficiently impregnated.
In the solution, the weight ratio of the copper element to the alkali metal element is in the range of 1: 0.2 to 1: 4.0, and the weight ratio of the copper element to the lanthanoid element is 1: 0.2 to 1: A range of 6.0 is preferred. The weight ratio of copper element to alkali metal element is in the range of 1: 0.2 to 1: 2.0, and the weight ratio of copper element to lanthanoid element is 1: 0.2 to 1: 3. More preferably, the weight ratio of copper element to alkali metal element is 1: 0.3 to 1: 1.5, and the weight ratio of copper element to lanthanoid element is 1: 0.3. More preferably, the weight ratio of copper element to alkali metal element is 1: 0.4 to 1: 1.0, and the weight ratio of copper element to lanthanoid element is Most preferably, it is 1: 0.4 to 1: 2.0. It is preferable to use a solution containing an active ingredient in the above range as a solution containing copper because each element is easily complexed, a long life is obtained, and the regenerated catalyst for producing chlorine is excellent in activity.

  As the active ingredient, the copper compound, alkali metal compound and lanthanoid compound to be dissolved and mixed in the solution may be any compound, salt or complex salt as long as the object of the present invention is not impaired. , Sulfates, acetates, carbonates, oxalates, alkoxides or complex salts. Among these, chloride, nitrate, or acetate is preferable because it can easily form a complex salt.

  The solution may contain other components other than the active ingredient and the carrier as long as the object of the present invention is not impaired. Examples of other components include ruthenium, palladium, iridium, vanadium, niobium, aluminum, alkaline earth metal elements, other rare earth elements such as lanthanum, cerium, ytterbium, scandium, and yttrium.

(Processing to dissolve and remove with water and / or acidic solution)
In the present invention, before the treatment step of impregnating the solution containing copper, a treatment step of dissolving and removing active components and poisoning components contained in the deteriorated catalyst using water and / or an acidic solution may be included. The catalyst is preferable because it is easier to regenerate the catalyst and it is easy to obtain an initial catalyst before use in chlorine production.

  As poisoning components contained in the deterioration catalyst, for example, metallic components such as nickel, cobalt, chromium, molybdenum, tungsten, iron, manganese, etc. mainly derived from a fluidized bed reactor, and nonmetallic components such as sulfur Is mentioned. If these poisoning components are contained in the regenerated catalyst, the catalyst activity may be lowered and the fluidity may be adversely affected, which is not preferable.

  In addition, for example, in the case of nickel, the content of poisoning components is preferably 1% by weight or less per 100% by weight of the deteriorated catalyst, and 0.5% by weight or less is preferable for catalyst activity and flow stability. From the viewpoint of maintaining the property over a long period of time, it is more preferable. The lower limit is not particularly limited.

  In addition, the solvent used in the acidic solution is not particularly limited, and examples thereof include water, alcohols such as methanol and ethanol, and mixtures thereof. Water is preferable because of easy handling. The type of acid contained in the acidic solution is not particularly limited, but examples include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as acetic acid, formic acid, and paratoluenesulfonic acid. This is preferable because the removal efficiency is high. In order to efficiently remove active components and poisoning components remaining in the porous carrier, it is more preferable to use water after using the acidic solution. The amount of the solvent used for the deteriorated catalyst is not particularly limited, but is preferably 1 to 10 times by weight, more preferably 2 to 6 times by weight with respect to the deteriorated catalyst. . If it is less than 1 times by weight, the solvent for the deteriorated catalyst is insufficient, and there is a possibility that dissolution and removal of poisoning components will not proceed efficiently. On the other hand, if it is larger than 10 times by weight, the amount of waste solvent becomes excessive, which is not preferable. In addition, the number of times of dissolution and removal can be twice or more in order to improve the efficiency of dissolution and removal. In this case, after adding the solvent to the deteriorated catalyst, separation of the deteriorated catalyst and the solvent by filtration or the like is performed a plurality of times, thereby making it possible to efficiently remove the active components and poisoned components. The treatment step of dissolving and removing in this way is preferable because the remaining poisoning components are reduced by repeating the number of times. Moreover, it is also possible to change the kind of solvent for every frequency | count. For example, an acid can be used for the first dissolution removal, and water can be used for the second and subsequent times. It is preferable to use an acidic solution and water in combination.

(Drying and / or baking after the treatment step to dissolve and remove)
In the present invention, it is preferable to include a step (1) of drying and / or firing after the treatment step of dissolving and removing and before the treatment step of impregnating the deterioration catalyst with a solution containing copper.

Although it does not specifically limit as drying conditions, It is preferable to implement on air | atmosphere or under pressure reduction, the drying temperature of 0-200 degreeC, and the conditions of drying time 10min-24hr.
Although it does not specifically limit as baking conditions, It is preferable to implement on the conditions of the baking time of 10 minutes-24 hours by the baking temperature of 200 to 600 degreeC under air | atmosphere.

In addition, the order of a drying process and a baking process is not specifically limited.
By drying and / or calcination, the residual solvent used in the treatment step of dissolving and removing can be separated from the deteriorated catalyst, and the porosity of the pore volume of the catalyst can be increased. By increasing the porosity, it is possible to secure a space for impregnation with a solution containing copper, which is preferable because the impregnation proceeds efficiently.

(Drying and / or baking after the treatment step of impregnating the solution containing copper)
In this invention, it is preferable to include the process (2) of drying and / or baking after the process process which makes the deterioration catalyst impregnate the solution containing copper.

Regarding the drying conditions and firing conditions, the above-described drying and / or firing step (1) can be referred to.
After the treatment step of impregnating the solution containing copper, the catalyst obtained is dried and / or calcined, so that a solvent unnecessary for the hydrogen chloride oxidation reaction can be removed in advance, This is preferable because it can be firmly fixed in the regenerated catalyst.

  When the amount of solvent remaining in the regenerated catalyst is larger than the pore volume of the catalyst, the regenerated catalyst is dried and / or calcined before filling the fluidized bed reactor with the catalyst, so that the solvent is reduced to less than the pore volume. Although it is preferable because it can be removed, if the amount of the remaining solvent is not more than the pore volume of the catalyst, it can be used for the reaction as it is, or it can be used for the reaction after removing the solvent by drying and / or calcination. Also good.

(Regenerated catalyst for chlorine production)
The regenerated catalyst for producing chlorine according to the present invention can be used as a catalyst for producing chlorine by oxidizing hydrogen chloride with oxygen, and is an active component of copper element (a), alkali metal element (b) and It is preferably composed of particles containing a lanthanoid element (c) having a bond dissociation energy with oxygen at 298 K in the range of 100 to 185 kcal / mol, and the particles have an average sphericity of 0.80 or more. In the regenerated catalyst for producing chlorine according to the present invention, these active components are usually supported on a porous particle carrier. The carrier can refer to the deteriorated catalyst.

  In the regenerated catalyst for producing chlorine according to the present invention, the copper element (a) may be contained in a monovalent or divalent state. Further, when comparing the copper content of the regenerated catalyst and the deteriorated catalyst, the copper content of the regenerated catalyst is more than the copper content of the deteriorated catalyst, preferably more than 0.1 wt%, more preferably, More than 0.2% by weight, more preferably more than 0.3% by weight. It is preferable that the copper content of the regenerated catalyst is 0.1% by weight or more than the content of the deteriorated catalyst because the effect of improving the hydrogen chloride oxidation activity is further increased. The upper limit is not particularly limited, but considering the regeneration efficiency, it is 12% by weight with respect to the copper content of the deteriorated catalyst.

  Further, the content of copper element is 0.5% by weight or more and 12.0% by weight or less, preferably 1.0% by weight or more and 10.0% by weight or less per 100% by weight of the regenerated catalyst. Is 1.2 wt% or more and 8.0 wt% or less. A regenerated catalyst having a copper content of greater than 12.0% by weight is difficult to produce, and when a regenerated catalyst with a high content is charged into a fluidized bed reactor, the fluidity between the catalysts may deteriorate. This is not preferable. On the other hand, a regenerated catalyst having a copper content of less than 0.5% by weight is not economically preferable because sufficient reaction activity of the catalyst cannot be obtained and chlorine cannot be obtained in a high yield.

  With respect to the alkali metal element (b) contained in the regenerated catalyst for chlorine production of the present invention, the deterioration catalyst can be referred to, but sodium and / or potassium is particularly preferable, and potassium is more preferable. The content of the alkali metal element (b) is not particularly limited, but is preferably 0.3% by weight or more and 12.0% by weight or less, more preferably 0.5% by weight or more and 10% by weight or less per 100% by weight of the catalyst for chlorine production. It is more preferably 0% by weight or less, and further preferably 0.6% by weight or more and 8.0% by weight or less.

  Regarding the lanthanoid element (c) contained in the regenerated catalyst for chlorine production of the present invention, among the so-called lanthanoid elements having atomic numbers 57 to 71, the lanthanoid having a bond dissociation energy with oxygen at 298 K in the range of 100 to 185 kcal / mol. It is an element, and the deterioration catalyst can be referred to.

  In the regenerated catalyst for chlorine production, if the bond dissociation energy of the lanthanoid element (c) exceeds 185 kcal / mol, the bond with oxygen becomes too strong, and if it is less than 100 kcal / mol, the affinity with oxygen decreases. Therefore, the reaction activity (chlorine yield) may not be sufficiently improved.

  In the regenerated catalyst for chlorine production, praseodymium, neodymium, samarium, europium, gadolinium, and dysprosium are preferable as the lanthanoid element (c). More preferable from the viewpoint of balance. These lanthanoid elements (c) may be used alone or in combination of two or more.

  The content of the lanthanoid element (c) is not particularly limited, but is preferably 0.5% by weight or more and 15.0% by weight or less per 100% by weight of the regenerated catalyst for chlorine production, 1.0% by weight or more, and 12. 0 wt% or less is more preferable, and 1.2 wt% or more and 10.0 wt% or less is more preferable.

  The regenerated catalyst for chlorine production according to the present invention contains a copper element (a), an alkali metal element (b), and a specific lanthanoid element (c), and the weight ratio thereof is not particularly limited, but the copper element (a) And the alkali metal element (b) have a weight ratio of 1: 0.2 to 1: 4.0, and the copper element (a) and the lanthanoid element (c) have a weight ratio of 1: 0. It is preferably in the range of 2 to 1: 6.0. The weight ratio of the copper element (a) to the alkali metal element (b) is in the range of 1: 0.2 to 1: 2.0, and the weight ratio of the copper element (a) to the lanthanoid element (c). Is more preferably 1: 0.2 to 1: 3.0, and the weight ratio of the copper element (a) to the alkali metal element (b) is 1: 0.3 to 1: 1.5. More preferably, the weight ratio of the copper element (a) to the lanthanoid element (c) is 1: 0.3 to 1: 2.5, and the copper element (a) and the alkali metal element (b) The weight ratio of 1: 0.4 to 1: 1.0, and the weight ratio of the copper element (a) and the lanthanoid element (c) is 1: 0.4 to 1: 2.0. Is most preferred. The above range is preferable because each element as an active component is easily complexed, a long life is obtained, and the regenerated catalyst for producing chlorine is excellent in activity.

  The shape of the regenerated catalyst for chlorine production according to the present invention may be any of a cylindrical shape, a ring shape, a granular shape, a spherical shape, and the like, but the catalyst has excellent wear resistance and durability, and also has good fluidity. Spherical shape is preferred. The average value of the sphericity of the regenerated catalyst particles is preferably 0.80 or more, and more preferably 0.90 or more. If it is less than 0.80, the wear and pulverization of particles due to friction cannot be ignored, and the fluidity during the reaction may deteriorate. If good fluidity cannot be ensured, the reaction efficiency decreases, resulting in a decrease in productivity. In addition, the upper limit of the average value of sphericity is 1, and when it is 1, it indicates a true sphere. Moreover, the average value of the sphericity of the regenerated catalyst particles can be determined by, for example, the average value of the circularity coefficient (sphericity of each particle) determined from an image of a micrograph such as a scanning electron microscope (SEM). .

  When the particle shape of the regenerated catalyst is not spherical or has a low sphericity, particle wear and pulverization due to friction cannot be ignored, and the fluidity during the reaction may decrease. If good fluidity cannot be ensured, the reaction efficiency may decrease, resulting in a decrease in productivity.

  Further, the regenerated catalyst for chlorine production according to the present invention is a component other than the above active component and carrier (other components) derived from a degradation catalyst, a treatment step of impregnating a solution containing copper, a treatment step of dissolving and removing, and the like. May be included. Other components include nickel element, cobalt element, chromium element, molybdenum element, tungsten element, iron element, manganese element, ruthenium element, palladium element, iridium element, vanadium element, niobium element, aluminum element, alkaline earth metal element And other rare earth elements such as lanthanum, cerium, ytterbium, scandium and yttrium.

  Further, in the regenerated catalyst for chlorine production according to the present invention, when it contains one or more other rare earth elements such as lanthanum, cerium, ytterbium, scandium, yttrium, it is preferable that the regenerated catalyst for chlorine production is 100 weights. % Is 0.001 wt% or more and 10 wt% or less. The weight ratio of the lanthanoid element (c) according to the present invention to other rare earth elements is not particularly limited, but is preferably in the range of 1: 0 to 1: 9.0, more preferably 1: 0. It is in the range of ˜1: 4.0.

  The regenerated catalyst for producing chlorine according to the present invention is not particularly limited. For example, it is desirable that the average particle diameter is 10 μm or more and less than 1000 μm, preferably 30 μm or more and less than 600 μm, more preferably 50 μm or more and less than 300 μm.

  The regenerated catalyst for producing chlorine according to the present invention is not particularly limited. For example, the average pore diameter is preferably 3 nm or more and 50 nm or less, and more preferably 6 nm or more and 30 nm or less. If the average pore diameter is less than 3 nm, it is difficult to introduce an active ingredient such as copper into the pores, which may cause aggregation on the surface, clogging of the pores, and the like. On the other hand, if the average pore diameter is larger than 50 nm, the surface area of the catalyst is decreased, and the reaction efficiency may be decreased, which is not preferable.

The regenerated catalyst for production of chlorine according to the present invention is not particularly limited. For example, the specific surface area is preferably 30 m ² / g or more and 1000 m ² / g or less, and is 50 m ² / g or more and 500 m ² / g or less. More preferably, it is 100 m ² / g or more and 300 m ² / g or less. In addition, the specific surface area in this invention can be measured using the BET method specific surface area measuring apparatus (BELSORP-max: Nippon Bell Co., Ltd. product), for example.

  The regenerated catalyst for producing chlorine according to the present invention is not particularly limited, but preferably has a bulk density of 0.20 g / ml or more and 1.00 g / ml or less, 0.30 g / ml or more, 0.80 g / ml. More preferably, it is less than ml.

  The regenerated catalyst for producing chlorine according to the present invention is not particularly limited, but the pore volume is preferably 0.3 ml / g or more and 3.0 ml / g or less, preferably 0.5 ml / g or more and 2.0 ml. / G or less, more preferably 0.6 ml / g or more and 1.5 ml / g or less. If it is less than 0.3 ml / g, the space in the pores is insufficient and the diffusion of the substrate becomes insufficient, the specific surface area is lowered, and the reaction efficiency is lowered. On the other hand, if it is larger than 3.0 ml / g, the strength as a catalyst is lowered, and the catalyst itself may be destroyed during the reaction, which is not preferable.

  The regenerated catalyst for chlorine production according to the present invention comprises particles containing copper elements (a), alkali metal elements (b) and specific lanthanoid elements (c) as active components, and the average sphericity of the particles If it is 0.80 or more, even if it consists of an aggregate | assembly of particle | grains, what is necessary is just to satisfy | fill said specific property as a whole.

  In addition, the regenerated catalyst for producing chlorine according to the present invention is preferably an aggregate of only particles having the same composition, but even if it satisfies the above-mentioned specific properties as a whole by mixing particles having different compositions. Good. Examples of particles having different compositions include particles having different compositions and physical properties, such as particles (P) that are inactive to the hydrogen chloride oxidation reaction (also referred to as inert particles (P)). In the present invention, when such inert particles (P) are used together with the regenerated catalyst, high fluidity can be maintained for a longer period of time, and chlorine can be supplied more stably. Such inert particles may be used by adding and mixing the inert particles contained in the deteriorated catalyst as they are to the regenerated catalyst as long as the object of the present invention is not impaired. The material of the reaction inactive particles is not particularly limited as long as it is not reactive with the reactant (hydrogen chloride, oxygen) and the product (chlorine, water). For example, silica, silica Examples thereof include alumina, alumina, titania, zirconia, and glass. Of these, silica and alumina are preferable, and silica is particularly preferable. Moreover, you may use the support | carrier before a catalyst is carry | supported as an inert particle (P). The shape of the inert particles (P) may be any of a cylindrical shape, a ring shape, a granular shape, a spherical shape, and the like, but in order to suppress wear during the reaction, it is preferably a spherical shape, It is more preferable that the average particle size is a spherical particle of 0.80 or more.

  In the present invention, the content of the copper element (a) in the regenerated catalyst for chlorine production is 0.5% by weight or more and 12.0% by weight or less per 100% by weight of the catalyst. In use, by mixing the inert particles (P), the content of the copper element (a) may be out of the above range as a result. It is preferable to maintain the content of copper element in the fluidized bed reactor at 0.3 wt% or more and 4.5 wt% or less per 100 wt% of the total catalyst in the reactor.

  Such a regenerated catalyst for producing chlorine according to the present invention can be suitably used as a catalyst for producing chlorine by oxidizing hydrogen chloride with oxygen in a fluidized bed reactor.

(Chlorine production method and chlorine production catalyst activity maintenance method)
The method for producing chlorine of the present invention is a method for producing chlorine by oxidizing hydrogen chloride with oxygen in the presence of a catalyst in a fluidized bed reactor, the catalyst producing the chlorine according to the present invention described above. Includes regenerated catalyst.

The method for maintaining the activity of the catalyst for producing chlorine according to the present invention is a method for maintaining the activity of the catalyst while regenerating the catalyst according to the present invention in order to efficiently produce chlorine.
In the present invention, the reaction activity and fluid stability of the catalyst bed in the fluidized bed reactor can be maintained over a long period of time, and chlorine can be produced more inexpensively and stably under a high chlorine reaction yield. obtain. Moreover, since the amount of catalyst discarded can be reduced, it can greatly contribute to the reduction of the environmental load.

In addition, the catalyst may contain the catalyst which has the activity which exists in a fluidized bed reactor, a deterioration catalyst, etc. in the range which does not impair the objective of this invention.
In the present invention, in order to regenerate a part of the catalyst whose activity has decreased while the reaction proceeds, a part or all of the catalyst is extracted from the outlet of the fluidized bed reactor, and after regenerating the extracted catalyst, The obtained regenerated catalyst or, if necessary, the inert particles (P) can be optionally charged into the fluidized bed reactor. This operation makes it possible to easily control the reaction activity of the fluidized bed reactor, to set it to any reaction activity, and to maintain the desired reaction activity and flow stability at a low cost over a long period of time. It becomes possible. The method for obtaining the regenerated catalyst is as described above.

  Further, the content of copper element in the fluidized bed reactor can be easily controlled within a range not impairing the object of the present invention, but preferably, the copper element content of all the catalysts contained in the fluidized bed reactor. The content is preferably 0.3% by weight or more and 4.5% by weight or less per 100% by weight of the total catalyst.

  In the present invention, a fluidized bed reactor is used, and the reaction system is preferably a flow type because chlorine can be continuously produced. Since this reaction is an equilibrium reaction, if the reaction temperature is too high, the yield of chlorine decreases, and if it is too low, the activity of the catalyst is not sufficient, so the reaction temperature is usually 250 ° C. or more and less than 500 ° C., preferably It is performed at 320 ° C. or higher and lower than 420 ° C. The pressure during the reaction is preferably not less than atmospheric pressure and less than 50 atm in consideration of operability.

  As an oxygen source for oxygen used in the reaction, air may be used as it is, but pure oxygen that can easily control the oxygen partial pressure is more preferable. Moreover, since the reaction of oxidizing hydrogen chloride with oxygen to generate chlorine is an equilibrium reaction, the yield of chlorine does not reach 100%, and it is necessary to separate unreacted hydrogen chloride from the product chlorine. . The stoichiometric molar ratio of hydrogen chloride to oxygen (hydrogen chloride / oxygen) is 4, but in general, it is possible to obtain higher activity and better fluidity by supplying oxygen in excess than the theoretical amount. The molar ratio of hydrogen chloride to oxygen (hydrogen chloride / oxygen) is preferably 0.5 or more and less than 3.0, more preferably 1.0 or more and less than 2.5. Moreover, you may distribute | circulate gas other than hydrogen chloride and oxygen in a reactor as needed.

Furthermore, at the start or end of the reaction, stable operation can be achieved by reducing the molar ratio of hydrogen chloride to oxygen or increasing the superficial velocity.
In addition, the source gas used may contain an impurity gas in addition to hydrogen chloride and oxygen, which are chlorine sources. Although it does not specifically limit as impurity gas, For example, chlorine, water, nitrogen, a carbon dioxide, carbon monoxide, hydrogen, carbonyl chloride, an aromatic compound, a sulfur-containing compound, a halogen-containing compound etc. are mentioned. In particular, carbon monoxide is known to cause a decrease in catalyst activity in conventional catalysts, but when using a catalyst for chlorine production, a significant decrease in catalyst activity is not recognized, and sufficient. Activity is maintained. The concentration contained in the raw material gas of carbon monoxide is preferably less than 10.0 vol%, and more preferably less than 6.0 vol%. If it is 10.0 vol% or more, the oxidation reaction of carbon monoxide proceeds remarkably, causing problems such as excessive heat generation and reduced chlorine yield.

  In the present invention, the supply rate of hydrogen chloride is usually preferably 100 NL / hr or more and less than 2000 NL / hr, more preferably 200 NL / hr or more, per 1 kg of the total catalyst present in the fluidized bed reactor. It is less than 1000 NL / hr.

  The gas superficial velocity in the present invention is preferably 0.01 m / sec or more and 1.0 m / sec or less, more preferably 0.02 m / sec or more and 0.5 m / sec or less. If the gas superficial velocity is less than 0.01 m / sec, the flow of the catalyst is insufficient and the fluidity is deteriorated. If the gas superficial velocity is higher than 1.0 m / sec, the catalyst will be scattered from the reactor, which is not preferable. In particular, in the present invention, it is not necessary to greatly change the gas superficial velocity even when the catalyst is withdrawn or charged with the regenerated catalyst, so that chlorine can be produced efficiently, economically and stably over a long period of time. it can.

In the method for producing chlorine in the present invention, the production process is not particularly limited, but preferably includes the following steps.
(1) A step of preheating a raw material gas containing hydrogen chloride and oxygen (2) A step of conducting an oxidation reaction of hydrogen chloride (3) A step of cooling a product gas containing hydrogen chloride, oxygen, chlorine and water (4) ) Steps for recovering and removing hydrogen chloride from the product gas (5) Steps for dehydrating the product gas (6) Steps for compressing and cooling the product gas and separating chlorine as liquefied chlorine

  In the step of preheating the raw material gas containing hydrogen chloride and oxygen, the gas is preferably heated to 100 ° C. or more and less than 400 ° C. before the gas is introduced into the fluidized bed reactor, and is preferably 150 ° C. or more and less than 350 ° C. More desirable. If the temperature to be heated in advance is less than 100 ° C., hydrogen chloride gas condenses in the system, and there is a possibility that device corrosion proceeds, which is not preferable.

  In the process of cooling the product gas containing hydrogen chloride, oxygen, chlorine and water, the product gas containing chlorine and water produced in the reactor and unreacted hydrogen chloride and oxygen at about 250 ° C. to 500 ° C. Is cooled by a refrigerant. The refrigerant is not particularly limited, but water is preferable.

  The step of recovering / removing hydrogen chloride from the product gas aims at recovering / removing unreacted hydrogen chloride from the product gas containing hydrogen chloride, oxygen, chlorine, and water. The method for recovering and removing hydrogen chloride is not particularly limited, but a method in which hydrogen chloride is absorbed by the recovery medium is preferable. The recovery medium is not particularly limited, but water is preferable because of easy handling. In addition, the step of cooling the product gas and the step of absorbing hydrogen chloride may be performed using separate apparatuses or may be performed using the same apparatus.

  The step of dehydrating the product gas is intended to remove water from the product gas containing chlorine, oxygen, and water. The dehydration method is not particularly limited, and methods such as a cooling dehydration method, an absorption dehydration method, an adsorption dehydration method, and a compression dehydration method can be suitably used, and a method by an absorption dehydration method is particularly preferable. By using this process, residual moisture contained in the product gas can be removed almost completely.

  In the step of compressing and cooling the product gas and separating chlorine as liquefied chlorine, the product gas from which moisture has been removed in the previous step is compressed and cooled to liquefy the chlorine and separate it from the gas phase. At this time, the gas phase after chlorine is liquefied and separated contains oxygen and unrecovered chlorine. This gas containing oxygen can be used as a raw material gas in the (2) hydrogen chloride oxidation reaction step by reintroducing it into the step of (1) preheating the hydrogen chloride and oxygen-containing raw material gas in advance. it can.

Through these steps, high-purity chlorine can be produced continuously and efficiently.
In the present invention, in order to improve fluidity, particles (P) that are inactive to the hydrogen chloride oxidation reaction can be used together with a catalyst for producing chlorine in the reactor. The use ratio of the inert particles (P) at this time is not particularly limited, but is 1% by weight or more based on the total particles composed of all the catalysts and inert particles present in the fluidized bed reactor. 80% by weight or less, preferably 2% by weight or more and 50% by weight or less, more preferably 2% by weight or more and 40% by weight or less. If the addition amount of the inert particles is less than 1% by weight, the effect of improving the fluidity may be lowered, and if it is more than 80% by weight, the yield of chlorine may be reduced. The inert particles (P) are as described above.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.
In addition, unless otherwise indicated, the activity evaluation of the catalyst of the following example or reference example was implemented on the conditions of the following catalytic reaction test methods. In the following examples and reference examples, the measurement and evaluation of each property were carried out as follows.

[1] Catalytic reaction test method Quartz sand is filled in the lower part of a glass reaction tube (see FIG. 1) having an inner diameter of 16 mm in which a glass filter having a thickness of 3 mm is installed in the hollow part, and the glass filter in the upper part of the glass filter. Charge 21.5 ml of catalyst. From the bottom of the glass reaction tube, 90.0 Nml / min of hydrogen chloride and 45.0 Nml / min of oxygen were supplied, and the reaction was carried out at a reaction temperature of 380 ° C. under normal pressure while flowing the catalyst. The gas superficial velocity at this time was 2.8 cm / sec, and the supply amount of hydrogen chloride per 1 kg of the catalyst was about 600 NL / hr.

[2] Yield of chlorine Potassium iodide (Kanto Chemical Co., Inc., for oxidant measurement) is dissolved in water to prepare a 0.2 mol / L solution. The generated gas was absorbed into the 300 ml of the solution from the reaction tube for 8 minutes. This solution was titrated with a 0.1 mol / L sodium thiosulfate solution (Kanto Chemical Co., Ltd.), and the amount of generated chlorine was measured to determine the yield of chlorine. In the oxidation reaction of hydrogen chloride, no by-products other than chlorine and water are observed, so the yield of chlorine is almost the same as the conversion rate of hydrogen chloride.

[3] Evaluation of catalyst fluidity The oxidation reaction of hydrogen chloride was carried out by the method described in the catalytic reaction test method except that the reaction temperature was 360 ° C. The temperature difference between A and B was measured when the lower part of the catalyst layer, that is, the part in contact with the glass filter was A, and the part 40 mm above the glass filter was B. When the temperature difference was less than ± 2 ° C., the fluidity was good, and when the temperature difference was ± 2 ° C. or more, the fluidity was judged as poor.

[4] Measurement of average sphericity The average sphericity was measured according to the following procedure.
1. The measurement sample was fixed on the sample stage with an adhesive tape and photographed using a scanning electron microscope (SEM).

2. The SEM image was taken into an image analyzer, the sphericity (circularity coefficient) of each particle was measured, and the average sphericity was calculated from the number of measured particles. The measurement target was particles having an equivalent circle diameter of 30 μm or more, and the number of measured particles was 1000 or more.
In addition, the apparatus and measurement conditions used for the measurement are as follows.

Scanning electron microscope (SEM): S-4800 manufactured by Hitachi High-Technologies Corporation
Acceleration voltage: 30 kV, emission current: 20 μA, magnification: 30 times Image analyzer: Leica Q-win manufactured by Leica Microsystems

[5] Concentration of each element in the catalyst In the present invention, the content of each element in the catalyst was measured using a fluorescent X-ray analysis method (LAB CENTER XRE-1700, manufactured by Shimadzu Corporation).

[Reference Example 1]
As a support, spherical silica (Fuji Silysia Chemical Co., Ltd., Q-15, particle size distribution: 75 to 300 μm, physical property values from manufacturer analysis table are average pore diameter: 15 nm, average particle diameter: 150 μm, bulk density: 0.4 g. / Ml, pore volume: 1.2 ml / g).

  59.0 kg of water, cupric chloride (Wako Pure Chemicals, special grade) 4.04 kg, samarium chloride hexahydrate (Wako Pure Chemicals, special grade) 4.55 kg, potassium chloride (Wako Pure Chemicals, special grade) 2.15 kg Was added to make an aqueous solution. After 120 kg of this aqueous solution was impregnated with a silica carrier by spray impregnation, the water was removed using a reduced pressure rotary dryer to obtain Reference Catalyst 1. The concentration of copper element contained in the reference catalyst 1 is 1.5% by weight, the concentration of potassium element is 0.9% by weight, the concentration of samarium element is 1.5% by weight, and the concentration of nickel element is 0.00% by weight. %, And the average sphericity was 0.925.

  The chlorine yield and fluidity of the obtained reference catalyst 1 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in Reference Catalyst 1 with oxygen.

[Reference Catalyst 1 Hydrochloric Acid Oxidation Treatment]
In a cylindrical pure nickel reactor including an upright internal and a horizontal internal, the inner diameter in the horizontal cross section of the portion where the catalyst layer exists is 2.70 m and the equivalent diameter in the cross section is 0.84 m. 1 was filled so that the packed bed height was 2.80 m. At this time, the content of the copper element contained in the catalyst layer was 1.50% by weight. After heating the catalyst layer temperature inside the reactor to 350 ° C. by heating, hydrogen chloride gas: 370 NL / hr, oxygen gas: 230 NL / hr. Gas other than hydrogen chloride and oxygen: A mixed gas consisting of 200 NL / hr was introduced, and a hydrogen chloride oxidation reaction was carried out while flowing the catalyst. At this time, the reaction temperature increased to nearly 400 ° C. due to the exotherm due to the progress of the reaction. After the reaction reached a steady state, it was maintained for 300 hr. After 300 hours, the supply of hydrogen chloride gas was stopped and the catalyst layer was cooled. The catalyst after cooling was taken out and designated as deteriorated catalyst 1.

[Reference Example 2]
The concentration of the copper element contained in the deterioration catalyst 1 is 0.89% by weight, the concentration of the potassium element is 0.58% by weight, the concentration of the samarium element is 1.03% by weight, and the concentration of the nickel element is 0.10% by weight. The average sphericity was 0.924.

  The chlorine yield and fluidity of the deteriorated catalyst 1 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the deteriorated catalyst 1 with oxygen.

[Example 1]
Add 320 g of 3 wt% nitric acid aqueous solution into a 1000 ml glass beaker. 80 g of the deteriorated catalyst 1 was added thereto and stirred at room temperature for 20 minutes. After completion of the stirring, the slurry containing the deteriorated catalyst 1 is filtered under reduced pressure, and then continuously washed with 300 g of water three times. After washing with water, 179.4 g of wet cake 1 was recovered. When the moisture content of the collected wet cake 1 was measured, it was 58.0 wt%. The wet cake 1 was filled into a 1000 ml glass eggplant flask, evaporated to dryness at 80 ° C. using an evaporator, and after washing, the catalyst 1 (copper element: 0.02 wt% per 100 wt% catalyst, potassium element: 75.2 g of 0.01% by weight, element of samarylum: 0.06% by weight, element of nickel: 0.01% by weight) was obtained.

  In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to form an aqueous solution, and at room temperature, after washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 1. The concentration of the copper element contained in the regenerated catalyst 1 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.919.

  Chlorine yield and fluidity of the obtained regenerated catalyst 1 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy value of the lanthanoid element in the regenerated catalyst 1 with oxygen.

[Example 2]
A washed catalyst 2 and a regenerated catalyst 2 were obtained in the same manner as in Example 1 except that the nitric acid concentration in the aqueous nitric acid solution was 1 wt%. The concentration of the copper element contained in the regenerated catalyst 2 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.920.

  The chlorine yield and fluidity of the obtained regenerated catalyst 2 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 2 with oxygen.

[Example 3]
A washed catalyst 3 and a regenerated catalyst 3 were obtained in the same manner as in Example 1 except that water was used instead of the 3 wt% nitric acid aqueous solution. The concentration of the copper element contained in the regenerated catalyst 3 is 1.6% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.7% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.917.

  Chlorine yield and fluidity of the obtained regenerated catalyst 3 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 3 with oxygen.

[Example 4]
A post-washing catalyst 4 and a regenerated catalyst 4 were obtained in the same manner as in Example 1 except that a 3 wt% hydrochloric acid aqueous solution was used instead of the 3 wt% nitric acid aqueous solution. The concentration of copper element contained in the regenerated catalyst 4 is 1.5% by weight, the concentration of potassium element is 0.9% by weight, the concentration of samarium element is 1.5% by weight, and the concentration of nickel element is 0.00% by weight. The average sphericity was 0.921.

  The chlorine yield and fluidity of the obtained regenerated catalyst 4 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 4 with oxygen.

[Example 5]
The wet cake 1 prepared by the method described in Example 1 was dried at 80 ° C. for 3 hours and then calcined at 420 ° C. for 3 hours to obtain a catalyst 5 after washing.

  In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 5 was added, and the mixture was evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 5. The concentration of the copper element contained in the regenerated catalyst 5 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.923.

  Chlorine yield and fluidity of the obtained regenerated catalyst 5 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy value of the lanthanoid element in the regenerated catalyst 5 with oxygen.

[Example 6]
A wet cake 1 was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to make an aqueous solution, 119.0 g of wet cake 1 was added thereto, and the mixture was evaporated to dryness at 80 ° C. using a rotary evaporator to obtain a regenerated catalyst 6. The concentration of the copper element contained in the regenerated catalyst 6 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01%. % By weight, and the average sphericity was 0.917.

  Chlorine yield and fluidity of the obtained regenerated catalyst 6 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 6 with oxygen.

[Example 7]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 12.5 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 7. The concentration of the copper element contained in the regenerated catalyst 7 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.920.

  The chlorine yield and fluidity of the obtained regenerated catalyst 7 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 7 with oxygen.

[Example 8]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500-ml glass eggplant flask, 125 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain a regenerated catalyst 8. The concentration of copper element contained in the regenerated catalyst 8 is 1.5% by weight, the concentration of potassium element is 0.9% by weight, the concentration of samarium element is 1.5% by weight, and the concentration of nickel element is 0.01% by weight. The average sphericity was 0.921.

  The chlorine yield and fluidity of the obtained regenerated catalyst 8 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 8 with oxygen.

[Example 9]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 25.0 g of water, 2.89 g of cupric chloride (Wako Pure Chemicals, special grade), 3.25 g of samarium chloride hexahydrate (Wako Pure Chemicals, special grade), potassium chloride (Wako Pure Chemicals) 1.53 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added thereto and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain a regenerated catalyst 9. The concentration of copper element contained in the regenerated catalyst 9 is 2.5% by weight, the concentration of potassium element is 1.5% by weight, the concentration of samarium element is 2.5% by weight, and the concentration of nickel element is 0.01% by weight. Met. The obtained regenerated catalyst 9 and the silica support 1 were mixed at a weight ratio of 6: 4 to obtain a mixed catalyst 1. The average sphericity of the mixed catalyst 1 was 0.915.

  The chlorine yield and fluidity of the mixed catalyst 1 were measured and evaluated by the above methods. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the mixed catalyst 1 with oxygen.

[Example 10]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 37.5 g of water, 6.21 g of cupric chloride (Wako Pure Chemical, special grade), 6.98 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical) , Special grade) 3.30 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 10. The concentration of the copper element contained in the regenerated catalyst 10 is 5.0% by weight, the concentration of the potassium element is 3.0% by weight, the concentration of the samarium element is 5.0% by weight, and the concentration of the nickel element is 0.01% by weight. Met. The obtained regenerated catalyst 10 and the silica carrier 1 were mixed at a weight ratio of 3: 7 to obtain a mixed catalyst 2. The average sphericity of the mixed catalyst 2 was 0.912.

  The chlorine yield and fluidity of the mixed catalyst 2 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the mixed catalyst 2 with oxygen.

[Example 11]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500-ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.89 g of samarium chloride hexahydrate (Wako Pure Chemical, special grade), sodium chloride (Wako Pure Chemical, special grade) ) 1.20 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 11. The concentration of the copper element contained in the regenerated catalyst 11 is 1.5% by weight, the concentration of the sodium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.919.

  The chlorine yield and fluidity of the obtained regenerated catalyst 11 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 11 with oxygen.

[Example 12]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.90 g of europium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 12. The concentration of the copper element contained in the regenerated catalyst 12 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the europium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.917.

  The chlorine yield and fluidity of the obtained regenerated catalyst 12 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy value of the lanthanoid element in the regenerated catalyst 12 with oxygen.

[Example 13]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemical, special grade), 1.86 g of neodymium chloride hexahydrate (Wako Pure Chemical, special grade), potassium chloride (Wako Pure Chemical, special grade) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 13. The concentration of elemental copper contained in the regenerated catalyst 13 is 1.5% by weight, the concentration of potassium element is 0.9% by weight, the concentration of neodymium element is 1.5% by weight, and the concentration of nickel element is 0.01% by weight. And the average sphericity was 0.915.

  The chlorine yield and fluidity of the obtained regenerated catalyst 13 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 13 with oxygen.

[Example 14]
A catalyst 1 after washing was obtained in the same manner as in Example 1.
In a 500 ml glass eggplant flask, 25 g of water, 1.68 g of cupric chloride (Wako Pure Chemicals, special grade), 1.94 g of praseodymium chloride heptahydrate (Wako Pure Chemicals, special grade), potassium chloride (Wako Pure Chemicals, special grade) 0.90 g was added to make an aqueous solution. After washing, 50.0 g of catalyst 1 was added and evaporated to dryness at 80 ° C. using a rotary evaporator to obtain regenerated catalyst 14. The concentration of the copper element contained in the regenerated catalyst 14 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the praseodymium element is 1.5% by weight, and the concentration of the nickel element is 0.01% by weight. The average sphericity was 0.920.

  The chlorine yield and fluidity of the obtained regenerated catalyst 14 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 14 with oxygen.

[Example 15]
In a 500 ml glass eggplant flask, 25 g of water, 0.56 g of cupric chloride (Wako Pure Chemicals, special grade), 0.50 g of samarium chloride hexahydrate (Wako Pure Chemicals, special grade), potassium chloride (Wako Pure Chemicals, special grade) ) 0.23 g was added to make an aqueous solution, 50.0 g of the deteriorated catalyst 1 was added thereto, and it was evaporated to dryness at 80 ° C. using a rotary evaporator to obtain a regenerated catalyst 15. The concentration of the copper element contained in the regenerated catalyst 15 is 1.5% by weight, the concentration of the potassium element is 0.9% by weight, the concentration of the samarium element is 1.5% by weight, and the concentration of the nickel element is 0.09% by weight. The average sphericity was 0.919.

  The chlorine yield and fluidity of the obtained regenerated catalyst 15 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 15 with oxygen.

[Example 16]
Add 25 g of water and 0.28 g of cupric chloride (Wako Pure Chemicals, special grade) to a 500 ml glass eggplant flask to make an aqueous solution, add 50.0 g of deteriorated catalyst 1 to this, and evaporate at 80 ° C. using a rotary evaporator. The catalyst was dried and the regenerated catalyst 16 was obtained. The concentration of the copper element contained in the regenerated catalyst 16 is 1.2% by weight, the concentration of the potassium element is 0.58% by weight, the concentration of the samarium element is 1.03% by weight, and the concentration of the nickel element is 0.10% by weight. The average sphericity was 0.914.

  The chlorine yield and fluidity of the obtained regenerated catalyst 16 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy values of the lanthanoid elements in the regenerated catalyst 16 with oxygen.

[Example 17]
Add 25 g of water and 0.046 g of cupric chloride (Wako Pure Chemicals, special grade) to a 500 ml glass eggplant flask to make an aqueous solution, add 50.0 g of deteriorated catalyst 1 to this, and evaporate at 80 ° C. using a rotary evaporator. The catalyst was dried to obtain a regenerated catalyst 17. The concentration of copper element contained in the regenerated catalyst 17 is 0.94% by weight, the concentration of potassium element is 0.58% by weight, the concentration of samarium element is 1.03% by weight, and the concentration of nickel element is 0.10% by weight. And the average sphericity was 0.918.

  The chlorine yield and fluidity of the obtained regenerated catalyst 17 were measured and evaluated by the methods described above. The results are shown in Table 2 together with the bond dissociation energy value of the lanthanoid element in the regenerated catalyst 17 with oxygen.

  According to the present invention, in a fluidized bed reactor, a deteriorated catalyst having a reduced performance can be efficiently and economically regenerated with a high recovery rate, and the initial performance of the catalyst has been recovered, that is, the catalytic activity is improved. High yield of a regenerated catalyst for chlorine production suitable for reaction in a fluidized bed reactor that is high, has a long catalyst life, can be stably supplied at low cost, and can maintain high fluidity for a long time without sticking. Can be provided at.

  Further, according to the chlorine production method of the present invention, chlorine can be produced stably, continuously and efficiently over a long period of time, and more economically. According to the catalyst activity maintaining method of the present invention, the excellent reaction activity and high flow stability of the catalyst can be maintained over a long period of time, and the performance of the plant can be ensured over a long period of time.

  Furthermore, according to the present invention, the deteriorated catalyst can be reused efficiently, so that the burden on the environment can be minimized.

1 generated gas 2 glass reaction tube (inner diameter: 16 mm)
3 Heater 4 Catalyst layer 5 Glass filter 6 Quartz sand 7 Raw material gas

Claims (18)

Regeneration for chlorine production, including one or more treatment steps of impregnating a deteriorated catalyst used in producing chlorine by oxidizing hydrogen chloride with oxygen using a fluidized bed reactor once or twice. A method for producing a catalyst,
The deterioration catalyst is a porous particle having an active component containing (A) a copper element, (B) an alkali metal element, and (C) a lanthanoid element whose bond dissociation energy with oxygen at 298K satisfies 100 to 185 kcal / mol. A method for producing a regenerated catalyst for producing chlorine, characterized in that the catalyst is a catalyst supported on a carrier.   The method for producing a regenerated catalyst for chlorine production according to claim 1, wherein the obtained regenerated catalyst has a copper content higher than that of the deteriorated catalyst.   The treatment step of impregnating the solution containing copper with the active component and poisoning component contained in the deteriorated catalyst is dissolved and removed with water and / or an acidic solution before the treatment step of impregnating the solution containing copper. A method for producing a regenerated catalyst for producing chlorine according to 1 or 2.   The method for producing a regenerated catalyst for chlorine production according to claim 3, further comprising a drying and / or calcination step after the dissolving and removing step.   The chlorine according to any one of claims 1 to 4, wherein the solution containing copper contains a lanthanoid having a bond dissociation energy with copper, an alkali metal, and oxygen at 298K of 100 to 185 kcal / mol. A method for producing a regenerated catalyst for production.   The method for producing a regenerated catalyst for chlorine production according to any one of claims 1 to 5, further comprising a drying and / or calcination step after the treatment step of impregnating the solution containing copper.   The chlorine according to any one of claims 1 to 6, wherein the obtained regenerated catalyst has a copper content of 0.1 wt% or more higher than the copper content of the deteriorated catalyst. A method for producing a regenerated catalyst for production.   The method for producing a regenerated catalyst for chlorine production according to any one of claims 1 to 7, wherein an average sphericity of the obtained regenerated catalyst is 0.80 or more. A method for regenerating a deteriorated catalyst, wherein the deteriorated catalyst is treated by impregnating a solution containing copper once or twice or more.
The deterioration catalyst is a catalyst used when producing chlorine by oxidizing hydrogen chloride with oxygen using a fluidized bed reactor, and (A) a copper element, (B) an alkali metal element, and (C ) An active component containing a lanthanoid element satisfying a bond dissociation energy with oxygen at 298 K of 100 to 185 kcal / mol is a catalyst supported on a porous particle carrier.
A method for regenerating a deteriorated catalyst.   The method for regenerating a deteriorated catalyst according to claim 9, wherein the obtained regenerated catalyst has a copper content higher than a copper content of the deteriorated catalyst.   The active component and poisoning component contained in the deteriorated catalyst are dissolved and removed with water and / or an acidic solution before the treatment of impregnating the solution containing copper. 11. A method for regenerating a deteriorated catalyst according to 10.   12. The method for regenerating a deteriorated catalyst according to claim 11, wherein drying and / or calcination is performed after the treatment for dissolving and removing.   The deterioration according to any one of claims 9 to 12, wherein the solution containing copper contains a lanthanoid satisfying a bond dissociation energy with copper, an alkali metal, and oxygen at 298K of 100 to 185 kcal / mol. Catalyst regeneration method.   The method for regenerating a deteriorated catalyst according to any one of claims 9 to 13, wherein drying and / or calcination is performed after the treatment of impregnating the solution containing copper.   The deteriorated catalyst according to any one of claims 9 to 14, wherein the obtained regenerated catalyst has a copper content of 0.1 wt% or more higher than the copper content of the deteriorated catalyst. How to play.   The method for regenerating a deteriorated catalyst according to any one of claims 9 to 15, wherein the regenerated catalyst has an average sphericity of 0.80 or more. In the fluidized bed reactor, a catalyst is used to oxidize hydrogen chloride with oxygen to produce chlorine, and the content of copper element in the total catalyst contained in the fluidized bed reactor is: 0.3 wt% or more and 4.5 wt% or less per 100 wt% of the total catalyst,
A part of the catalyst is extracted from the outlet of the fluidized bed reactor, and the extracted catalyst is impregnated with a solution containing at least copper once or twice, and the obtained catalyst is used in the fluidized bed reactor. Including the process of charging
The extracted catalyst has an active component containing (A) a copper element, (B) an alkali metal element, and (C) a lanthanoid element whose bond dissociation energy with oxygen at 298K satisfies 100 to 185 kcal / mol. Including a catalyst supported on a carrier of particles,
A method for producing chlorine characterized by the above. A part of the catalyst for producing chlorine used for producing chlorine by oxidizing hydrogen chloride with oxygen is extracted from the outlet of the fluidized bed reactor, and a solution containing at least copper is extracted once or two in the extracted catalyst. It is a method of maintaining the activity of the catalyst while regenerating the catalyst, performing the impregnation process more than once, and charging the obtained catalyst into the fluidized bed reactor,
The content of copper element in all catalysts contained in the fluidized bed reactor is 0.3 wt% or more and 4.5 wt% or less per 100 wt% of the total catalyst,
The extracted catalyst is composed of (A) a copper element, (B) an alkali metal element, and (C) an active component containing a lanthanoid element satisfying a bond dissociation energy with oxygen at 298K of 100 to 185 kcal / mol. Including a catalyst supported on a carrier of particles,
A method for maintaining the activity of a catalyst for producing chlorine.

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