JPH02293044A - Production of desulfurizing agent - Google Patents

Abstract

PURPOSE:To obtain a desulfurizing agent having superior desulfurizing performance by forming a metal oxide mixture by coprecipitation from an aq. soln. contg. water soluble salts of Cu and a specified metal and by reducing the metal oxide mixture with hydrogen. CONSTITUTION:An aq. soln. contg. water soluble salts of Cu and a metal such as Cr, Mn or Co is prepd. A water soluble Zn salt is preferably added to the soln., a water soluble Al salt is further added and a metal oxide mixture contg. copper oxide is formed by coprecipitation from the soln. The metal oxide mixture has a uniform compsn., consists of fine grains and contains copper oxide kept in a highly dispersed state. The mixture is then reduced with hydrogen under mild conditions, e.g. in the presence of a gaseous mixture of <=6vol.% hydrogen with an inert gas. The resulting desulfurizing agent has such desulfurizing performance that the amt. of sulfur is reduced to <=0.1ppb.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing a desulfurizing agent. In more detail,
This invention relates to a method for producing a desulfurizing agent used for desulfurizing various gases and oils.

Problems to be solved by conventional techniques and inventions
Various gases and oils, such as industrial gas, natural gas, and Ishiura distillate, are subjected to a desulfurization process using a desulfurization agent to remove the sulfur content in order to remove the negative effects of the sulfur contained in them.・Used after removal. As a desulfurization agent, copper is known to have excellent desulfurization performance, and is usually used in a state where copper is supported on a carrier such as activated carbon, alumina, or zinc oxide.

However, known copper-based desulfurization agents have a sulfur adsorption capacity (
Since the saturated adsorption capacity is low, it is not only necessary to use a large amount in order to continue desulfurization for a long time, but also the lp
It has been difficult to stably perform desulfurization to levels as low as pb (sulfur, hereinafter the same) or lower.

The present invention was developed by the present inventors as a result of repeated various studies in view of the problems with conventional copper-based desulfurization agents as described above. The sulfur content in various gases and oils can be reduced to 0.1 ppb or less by using a desulfurizing agent obtained by hydrogen reduction of a gold L oxide mixture containing copper oxide prepared by the method. The object of the present invention is to provide a method for producing a desulfurizing agent with excellent desulfurization performance.

Means for Solving the Problems> The method for producing a desulfurizing agent of the present invention, which was made to solve the above problems, uses a desulfurizing agent of the group consisting of chromium, manganese, cobalt, lanthanum, cerium, alkaline earth metals, vanadium, and zirconium. (hereinafter referred to as "metal group") and a water-soluble salt of copper, preferably, in addition, a water-soluble salt of zinc, more preferably, In addition, it is characterized in that a metal oxide mixture containing copper oxide prepared by a coprecipitation method from a water-soluble salt of aluminum is subjected to hydrogen reduction.

In the present invention, a metal oxide mixture containing copper oxide is prepared by a coprecipitation method.

First, we will explain how to prepare a metal oxide mixture by coprecipitation using a water-soluble salt of copper and a water-soluble salt of an element of the metal group. Although various water-soluble salts can be used as the catalyst, it is preferable to use nitrates, acetates, etc. that do not contain substances that poison the catalyst, and nitrates are particularly preferable. The coprecipitation method itself may be carried out by a method similar to that conventionally employed in the production of catalysts. For example, a mixed aqueous solution containing a water-soluble salt of copper and one or more water-soluble salts of elements of the metal group, and a basic compound (e.g., sodium carbonate, potassium carbonate, etc.)
an aqueous solution of purified water (for example,
(distilled water, ion-exchanged water, etc.) while stirring and neutralizing at a constant speed, a mixed slurry is generated. Next, the formed precipitate is washed, collected by filtration, and heated to 110 to 120°C.
After drying, add auxiliary agents if necessary and compression mold.
This is further carried out by firing at about 300° C., thus obtaining a metal oxide mixture containing copper oxide. In addition, each of these conditions may be selected as appropriate depending on the type of water-soluble salt of copper and water-soluble salt of an element of the metal group to be used.
It is not particularly limited.

The metal oxide mixture containing copper oxide obtained above is
The composition is uniform, the particles are fine, and the copper oxide is maintained in a highly dispersed state. Although the mixing ratio of copper oxide and the oxide component of the element of the metal group can vary within a wide range, it is usually preferred that the content of copper oxide is in the range of 10% by weight to 70% by weight. If there is too little copper, it will not be able to exhibit sufficient performance as a copper-based desulfurizing agent, and if there is too much copper,
Sintering occurs and the dispersion condition worsens. Then,
The desulfurizing agent of the present invention can be obtained by reducing the metal oxide mixture containing copper oxide thus obtained with hydrogen.

The above hydrogen reduction can be carried out by conventional methods, but
Since copper has a low melting point, heat tends to increase the particle size and decrease the surface area, and excessive heat changes the pore structure and changes the properties of the catalyst. Therefore, when reducing the metal oxide mixture with hydrogen, hydrogen reduction of copper oxide is an exothermic reaction, so under mild conditions, for example, hydrogen content of 6% by volume.
Reduction treatment while maintaining a temperature of about 150 to 300°C in the presence of a mixed gas of hydrogen and an inert gas (e.g., nitrogen, argon, etc.) adjusted to a certain degree, preferably about 0.5 to 4% by volume. It is preferable to do so.

In the desulfurization agent thus obtained, fine particle copper having a large surface area is uniformly dispersed and is in a highly active state, so that the sulfur adsorption power is extremely strong and large. Here, the metal that co-precipitates with copper must be one that keeps copper in a highly dispersed state and does not cause side reactions under actual desulfurization conditions. Generally, the metal that satisfies this condition is Elements of the metal group (i.e. chromium, manganese, cobalt, lanthanum, cerium, alkaline earth metals,
vanadium, zirconium, etc.).

The desulfurization agent obtained above is preferably a desulfurization agent containing a zinc component, and is obtained by incorporating the zinc component by coprecipitation during the preparation of the coprecipitation mixture, firing, and then reducing with hydrogen. That is, a mixed aqueous solution containing one or more water-soluble salts of copper, water-soluble salts of zinc (e.g., zinc nitrate, zinc acetate, etc.) and water-soluble salts of elements of the metal group, and an aqueous solution of a basic compound. A mixture containing copper oxide, zinc oxide and oxides of elements of the metal group is prepared by co-precipitation, drying and calcination, and then hydrogen reduction under the same conditions as above to remove the zinc component. A desulfurizing agent containing the desulfurization agent is obtained. Zinc oxide has the effect of keeping the copper in the desulfurization agent in a highly dispersed state after hydrogen reduction. Copper in desulfurization agents,
The atomic ratio of zinc and the elements of the metal group can vary within a wide range, but is usually copper:zinc:element of the metal group -1:0.3 to 1.
The ratio is preferably about 0:0.05 to 10 (atomic ratio), more preferably about 1:0.6 to 3:0.1 to 2 (atomic ratio). If the copper content is less than the above range, sufficient performance as a copper-based desulfurization agent cannot be exhibited, and if the copper content is more than the above range, sintering may occur and the dispersion state may deteriorate.

Furthermore, in order to improve the heat resistance of the desulfurizing agent obtained above, it is preferable to contain an aluminum component in addition to copper, zinc, and elements of the metal group. It can be obtained by incorporating an aluminum component by coprecipitation during the preparation of a coprecipitated mixture containing elemental components of the metal group and calcination, followed by hydrogen reduction. Namely, water-soluble salts of copper, water-soluble salts of zinc, water-soluble salts of aluminum (
For example, aluminum nitrate, sodium aluminate, etc.)
Co-precipitation from a mixed aqueous solution containing one or more water-soluble salts of elements of the metal group and an aqueous solution of a basic compound,
A mixture containing copper oxide, zinc oxide, aluminum oxide and oxides of elements of the metal group was prepared by drying and firing, and then hydrogen reduction was performed under the same conditions as above to prepare a mixture containing the aluminum component. A desulfurizing agent is obtained.

Aluminum oxide has the effect of preventing a decrease in the strength of the desulfurizing agent at high temperatures and significantly reducing the decrease in sulfur adsorption ability at high temperatures. The atomic ratios of copper, zinc, aluminum and elements of the metal group in the desulfurization agent can vary over a wide range, but are usually copper; zinc; aluminum; element of the bimetallic group -1:
The ratio is preferably about 0.3 to 10:0.05 to 2:0.05 to 10 (atomic ratio). If the copper content is less than the above range, sufficient performance as a copper-based desulfurization agent cannot be exhibited, and if the copper content is more than the above range, sintering may occur and the dispersion state may deteriorate. Furthermore, if the amount of aluminum is less than the above range, it cannot contribute to the improvement of heat resistance, and if it is more than the above range, there is a risk that the desulfurization performance may be reduced.

The desulfurization agent obtained by the method of the present invention can be used in the same manner as known types of desulfurization agents, for example, by filling it into an adsorption desulfurization device of a predetermined shape and passing the gas or oil to be purified through it. be done.

In addition, the desulfurization agent obtained by the method of the present invention has a high degree of adsorption performance that could not be purified with conventional adsorption desulfurization agents. It has particularly remarkable effects when used as a "secondary desulfurization agent" for desulfurization. Examples of the gases and oils to be purified include natural gas, ethane, propane, butane, LPG (liquefied petroleum gas), light naphtha, heavy naphtha, light kerosene, coke oven gas, and various city gases. be done.

In addition, when desulfurizing using the desulfurizing agent obtained by the method of the present invention, if necessary, for example, 150 to 3
For desulfurizing agents containing an aluminum component, heating may be carried out at approximately 150 to 400°C.

Effects of the Invention The desulfurizing agent obtained by the method of the present invention has excellent desulfurization performance,
Desulfurization agents that can significantly reduce the organic sulfur and inorganic sulfur content in various gases and oils (usually 0.1 ppb or less), and also contain zinc components, have even higher desulfurization performance and A desulfurizing agent containing an aluminum component has an effect of being excellent in heat resistance.

Examples> Hereinafter, the present invention will be explained in more detail based on Reference Examples, Examples, and Comparative Examples, but the present invention is not limited to these Examples.

Reference Example 1 Naphtha containing 100 ppm of sulfur was first heated in the presence of a Ni-Mo hydrodesulfurization catalyst at a temperature of 380°C, a pressure of 10 kg/c Sea-G, and a LHSV of 1.0 according to a conventional method.
After hydrogenolysis under the conditions of , hydrogen/naphtha-0.1 (molar ratio), desulfurization was carried out by contacting with a ZnO-based adsorption desulfurization agent. The concentration of sulfur compounds in the purified gas obtained was approximately 0.2 ppm.
Met.

Example 1 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate and chromium nitrate, and the resulting precipitate was washed with water and collected by filtration. It was molded into tablets and fired at about 300°C. The atomic ratio of copper and chromium in the fired body was about 1=2, respectively.

Next, a secondary desulfurization equipment (
Nitrogen gas containing 2% by volume of hydrogen was passed through the desulfurization layer (length 30 cm) to reduce the temperature at 200°C, and then 400g/h of the purified gas obtained in Reference Example 1 was passed through the desulfurization equipment at a temperature of 250°C.
Desulfurization was carried out again under the conditions of temperature and pressure of 8 kg/c4-G.

As a result, the concentration of sulfur compounds in the finally obtained refined gas decreased to an average of 1 ppb or less over 1000 hours of operation.

Comparative Example 1 Activated alumina carrier (surface area 1
When secondary desulfurization was carried out in the same manner as in Example 1 using a desulfurization agent with 5% copper supported on (00rrr/sr), sulfur compounds began to slip immediately after the start of operation, and 0% copper was carried in the purified gas. .05 ppm of sulfur compounds were detected.

Comparative Example 2 A sodium carbonate aqueous solution was added to an aqueous solution containing chromium nitrate at 85° C., and the resulting precipitate was washed with water, filtered, and then suspended in purified water again. Adding a copper nitrate aqueous solution to the suspension,
While stirring vigorously, an aqueous sodium carbonate solution was added at 85°C. The generated precipitate was thoroughly washed with water, collected by filtration, and then molded into tablets of 1/8 inch in height x 1/8 inch in diameter.
It was fired at 0°C. The atomic ratio of copper and chromium in the fired body was about 1:2, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the concentration of sulfur compounds in the final purified gas was 0.05 ppm 100 hours after the start of operation, and increased to 0.12 ppm after a further 24 hours.

Example 2 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, and chromium nitrate, and the resulting precipitate was washed with water and collected by filtration. The tablets were molded into a size and baked at about 300°C. The atomic ratio of copper:zinc:chromium in the fired body was about 1:1:1, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.1 ppb on average over 4000 hours of operation.
It had fallen below.

Comparative Example 3 A sodium carbonate aqueous solution was added to an aqueous solution containing zinc nitrate and chromium nitrate at 85°C, and the resulting precipitate was washed with water and collected by filtration.
It was suspended again in purified water. An aqueous solution containing copper nitrate was added to the suspension, and while stirring strongly, an aqueous sodium carbonate solution was added at 85°C. Wash the formed precipitate thoroughly with water,
After filtering, the mixture was molded into tablets of 1/8 inch in height x 1/8 inch in diameter, and fired at about 300°C. The atomic ratio of copper:zinc:chromium in the fired body was about 1:1:1, respectively.

Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the concentration of sulfur compounds in the final purified gas was 0.05 ppm 220 hours after the start of operation, and the concentration of sulfur compounds in the final purified gas was 0.05 ppm, and
After time elapsed, it increased to 0.1 ppm.

Example 3 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, and manganese nitrate,
After washing the resulting precipitate with water and collecting it by filtration, a height of 1/8 inch
It was molded into tablets with a diameter of 1/8 inch and fired at about 300°C. The atomic ratio of copper:zinc:manganese in the fired body is approximately 1=120. It was 8. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.1 ppb on average over 1000 hours of operation.
It had fallen below.

Example 4 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate and barium nitrate,
After washing the resulting precipitate with water and collecting it by filtration,
It was molded into tablets with a diameter of 1/8 inch and fired at about 300°C. The atomic ratio of copper:zinc;barium in the fired body was about 1:1:0.4, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.000000000000000 on average over 1500 hours of operation. lppb
It had fallen below.

Example 5 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, and zirconium nitrate, and the resulting precipitate was washed with water and collected by filtration. Molded into tablets of approximately 300 pieces
Calcined at ℃. The atomic ratio of copper:zinc:zirconium in the fired body was about 1:1:0.3, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then subjected to hydrogen reduction treatment in the same manner as in Example 1.
The purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as described above.

As a result, the sulfur compound concentration in the final purified gas was 0.1 ppb on average over 1000 hours of operation.
It had fallen below.

Example 6 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, and cobalt nitrate,
After washing the resulting precipitate with water and collecting it by filtration, a height of 1/8 inch
It was molded into tablets with a diameter of 1/8 inch and fired at about 300°C. The atomic ratio of copper:zinc:cobalt in the fired body was about 1:120.5, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.19 pb on average over 1000 hours of operation.
It had fallen below.

Example 7 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate and lanthanum nitrate,
After washing the resulting precipitate with water and collecting it by filtration,
The key was molded to a size of 1/8 inch in diameter and fired at about 300°C. The atomic ratio of copper:zinc:lanthanum in the fired body was about 1=1:0.1, respectively. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the concentration of sulfur compounds in the final purified gas was 0.000% on average over 1000 hours of operation. lppb
It had fallen below.

Example 8 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, aluminum nitrate, and chromium nitrate, and the resulting precipitate was washed with water and filtered, and then made into a 1/8 inch high x 1/8 inch diameter. It was molded into 8-inch tablets and fired at about 400°C. The atomic ratio of copper:zinc:aluminum:chromium in the fired body is approximately 1:1:0.7:
It was 0.5. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.1 ppb on average over 4000 hours of operation.
It had fallen below.

Example 9 A sodium carbonate aqueous solution was added as an alkaline substance to a mixed aqueous solution containing copper nitrate, zinc nitrate, aluminum nitrate, and manganese nitrate, and the resulting precipitate was washed with water and collected by filtration.
The key was molded into a size of 1/8 inch in height x 1/8 inch in diameter, and fired at about 400°C. Copper:zinc in the fired body:
The atomic ratio of aluminum and manganese is approximately 1:1:0.
7:0.3. Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the sulfur compound concentration in the final purified gas was 0.000000000000000 on average over 1500 hours of operation. lppb
It had fallen below.

Example 10 Aqueous sodium carbonate solution was added as an alkaline substance to a mixed aqueous solution containing steel nitrate, zinc nitrate, chromium nitrate, and manganese nitrate, and the resulting precipitate was washed with water and collected by filtration.
The key is molded into a size of /8 inches x 1/8 inch in diameter,
It was fired at about 400°C. The atomic ratios of copper:zinc; chromium:manganese in the fired body were about 1:1:0.7:0.3, respectively.

Next, the fired body was subjected to hydrogen reduction treatment in the same manner as in Example 1, and then the purified gas obtained in Reference Example 1 was subjected to secondary desulfurization in the same manner as in Example 1.

As a result, the concentration of sulfur compounds in the final purified gas was 0.000% on average over 1000 hours of operation. lppb
It had fallen below.

Example 11 The fired body obtained in Example 2 was reduced in the same manner as in Example 1, and then city gas 13A having the composition shown in Table 1 below was passed through it at a flow rate of IOOR/h, and the temperature was 200°C. , pressure o. It was removed at 0.02kg/c-G.

As a result, the concentration of sulfur compounds in the final purified gas was 0.000% on average over 1000 hours of operation. lppb
It had fallen below.

Table 1 Methane 86.9% by volume Ethane
8.1% by volume broban
3.7% by volume butane
1.3 volume% odorant dimethyl sulfide 3m
g-S/Nm't-butylmercabutane 2mg-S/
Nm' Example 12 The fired body obtained in Example 2 was reduced in the same manner as in Actual Relaxation Example 1, and then LPG (sulfur-containing 325 ppm) was passed through m-c' at a flow rate of 10047/h to reduce the temperature. Desulfurization was carried out at 200'C and a pressure of 0.02 kg/c Sea-G.

As a result, the sulfur compound concentration in the final purified gas was 0.19 pb on average over iooo hours of operation.
It had fallen below.

Claims (1)

[Claims] 1. A water-soluble salt of at least one element selected from the group consisting of chromium, manganese, cobalt, lanthanum, cerium, alkaline earth metals, vanadium, and zirconium and a water-soluble salt of copper are used. 1. A method for producing a desulfurizing agent, which comprises reducing a metal oxide mixture prepared by a coprecipitation method with hydrogen. 2. Using a water-soluble salt of at least one element selected from the group consisting of chromium, manganese, cobalt, lanthanum, cerium, alkaline earth metals, vanadium, and zirconium, a water-soluble salt of copper, and a water-soluble salt of zinc. 1. A method for producing a desulfurizing agent, which comprises reducing a metal oxide mixture prepared by a coprecipitation method with hydrogen. 3. A water-soluble salt of at least one element selected from the group consisting of chromium, manganese, cobalt, lanthanum, cerium, alkaline earth metals, vanadium, and zirconium, a water-soluble salt of copper, a water-soluble salt of zinc, and aluminum. 1. A method for producing a desulfurizing agent, which comprises hydrogen reducing a metal oxide mixture prepared by a coprecipitation method using a water-soluble salt of 4. Claims 1 to 3 in which the hydrogen reduction is carried out at 150 to 300°C using diluted hydrogen gas with a hydrogen concentration of 6% by volume or less.
A method for producing a desulfurizing agent according to any one of the above.