KR102085613B1 - A regeneration method of metal sulfurized catalyst - Google Patents

Abstract

The present invention relates to a method for regenerating a metal sulfide catalyst which continuously supplies hydrogen sulfide to a catalyst to maintain an active point of the sulfiding catalyst.

Description

Regeneration method of a metal sulfide catalyst in-situ {A REGENERATION METHOD OF METAL SULFURIZED CATALYST}

The present invention relates to a method for regenerating a metal sulfide catalyst.

In the reaction using a synthesis gas containing a sulfur compound, when a metal sulfide is used as the catalyst, the sulfur compound deteriorates the performance of the catalyst even in a very small amount when present in the process gas as a catalyst poisoning material, and irreversibly adsorbs to the active site. To reduce the lifespan. Therefore, the catalyst is mainly used to remove the sulfur compound through an adsorbent or an acid gas process, and then the process is cumbersome and uneconomical. In order to solve this problem, there is a method of using an active point of sulfur contained in the metal sulfur compound and using a catalyst made of metal sulfide in a state in which sulfur is not separately removed.

However, it is necessary to continuously supply sulfur compounds to the surface of the catalyst to maintain the active point of the sulfide. In particular, if the amount of sulfur contained in the original raw material is not sufficient, a continuously low amount of sulfur compound is supplied and eventually the active point of sulfur in the metal sulfide catalyst cannot be maintained, so that the catalyst is seriously deactivated.

Therefore, in order to solve this problem, the method of regenerating the deactivated catalyst of Japanese Patent Laid-Open No. 3110838 provides a method of regenerating the catalyst such as a method of burning and removing carbon deposited on the surface of the coated catalyst using oxygen. do. However, the regeneration method also has a cumbersome problem in the process of separately supplying a predetermined gas containing oxygen for regeneration of the catalyst.

Accordingly, one aspect of the present invention is to continuously supply hydrogen sulfide to the catalyst to maintain the active point of sulfur, thereby simplifying the process of regenerating the metal catalyst and regeneration of the metal sulfide catalyst which can minimize catalyst damage caused by external air exposure. To provide a way.

According to one aspect of the present invention, in a catalytic reaction using a metal sulfide catalyst, the method may include converting an active metal sulfide catalyst by supplying hydrogen sulfide to a surface of an inert metal sulfide catalyst.

The method may further include preparing hydrogen sulfide by reacting the sulfur compound with hydrogen or a mixed gas of hydrogen and nitrogen before supplying hydrogen sulfide to the catalyst to regenerate the metal sulfide catalyst.

The inert metal sulfide catalyst is M _x S _m , the active metal sulfide catalyst is M _x S _n , and x and n are the number of each element such that the value of oxidation number of all atoms is 0, where m is 0 To n-1.

M may be one or more selected from the group consisting of nickel (Ni), cobalt (Co), tungsten (W) and molybdenum (Mo).

The inert metal sulfide catalyst may be supported on a porous carrier comprising at least one selected from the group consisting of silica, aluminum and titania.

The sulfur compound is DMDS (dimethyl disulfide, C ₂ H ₆ S ₂ ), DMS (dimethyl sulfide, C ₂ H ₆ S), DMSO (dimethyl sulfoxide, C ₂ H ₆ SO), N-butyl mercaptan (C ₄ H ₁₀ S), Methyl Mercaptan (CH ₄ S) and TBPS (di-t-butyl polysulfide, C ₈ H1 ₈ S ₄ ) It may be one or more selected from the group consisting of.

The conversion to the active metal sulfide catalyst may be performed by supplying hydrogen sulfide to the surface of the inert metal sulfide catalyst at 220 to 310 ° C.

The method may further include heating the hydrogen sulfide supplied to 220 to 300 ° C. prior to the catalytic reaction using the metal sulfide catalyst.

Providing a method for regenerating a metal sulfide catalyst comprising supplying hydrogen sulfide which is not used for regeneration of the catalyst from the hydrogen sulfide supplied in the step of supplying the hydrogen sulfide to the inert metal sulfide catalyst to the metal sulfide catalyst. do.

The method for regenerating a metal sulfide catalyst according to the present invention uses hydrogen sulfide generated from a reaction of a sulfur compound and hydrogen, and continuously supplies hydrogen sulfide to a metal catalyst instead of a post-treatment method, which is a conventional metal sulfide regeneration method. By maintaining the active point of sulfur, the catalyst can be regenerated and used, which not only prevents oxidation and damage of the catalyst, but also has a very simple procedure and low maintenance cost.

1 is a schematic diagram showing the entire process of an exemplary metal sulfide catalyst regeneration of the present invention.
2 is a view showing the conditions for treating DMDS to a mixed gas of hydrogen and nitrogen to produce hydrogen sulfide according to an embodiment of the present invention.
3 shows the CO conversion of exemplary metal sulfide catalysts of the present invention.

1 is a schematic diagram showing a regeneration method of an inactivated metal sulfide catalyst according to an embodiment of the present invention.

As shown in FIG. 1, the regeneration method of the metal sulfide catalyst of the present invention provides a method of regenerating a metal sulfide catalyst by continuously supplying hydrogen sulfide to an inactivated metal sulfide catalyst to maintain an active point of sulfur.

More specifically, the present invention maintains the active site of sulfur by a method of continuously supplying a sufficient amount of hydrogen sulfide necessary for the catalytic reaction to the surface of the metal sulfide catalyst deactivated by reducing the sulfur compound supply amount. Therefore, according to the metal sulfide catalyst regeneration method of the present invention, it is possible to regenerate the performance of the metal sulfide catalyst in which deactivation has occurred.

Hydrogen sulfide may be further provided prior to supplying hydrogen sulfide or hydrogen sulfide to provide hydrogen sulfide to the surface of the deactivated metal sulfide catalyst.

In the latter case, for example, prior to the step of supplying hydrogen sulfide to the surface of the deactivated metal sulfide catalyst, the deactivated metal sulfide such as reacting a sulfur compound with a mixed gas of hydrogen and nitrogen to obtain hydrogen sulfide in FIG. It may further comprise the step of producing hydrogen sulfide supplied to the catalyst surface.

The hydrogen sulfide may be obtained by reacting hydrogen or a mixed gas of hydrogen and nitrogen with a sulfur compound.

In the preparing of the hydrogen sulfide, the concentration of hydrogen does not exceed the concentration of the prepared hydrogen sulfide. If the amount of hydrogen sulfide produced is less than the amount of hydrogen supplied, and the amount of hydrogen compound and unreacted hydrogen is significantly high, then hydrogen sulfide is applied to the catalyst to the hydrogen that is not reacted with the sulfur compound. Sulfur substituted on the surface of the catalyst can be released.

Therefore, it is preferable that the sulfur compound is supplied so that the concentration of hydrogen sulfide is maintained higher than the concentration of hydrogen gas measured at the time when hydrogen or hydrogen and nitrogen gas react with the sulfur compound to be converted into hydrogen sulfide. If conditions are maintained, the concentrations of hydrogen, nitrogen and sulfur compounds are not particularly limited.

Furthermore, the ratio of the volume of hydrogen and nitrogen gas is preferably 0.5-1.5: 8.5-9.5. For example, the ratio of the volume of hydrogen and nitrogen may be adjusted to be 1: 9. When the ratio of the volume of hydrogen is less than 0.5, hydrogen cannot be supplied in an amount sufficient to form hydrogen sulfide, and when it exceeds 1.5, a large amount of H ₂ S is generated, so that it is difficult to control the exotherm during the sulfidation reaction, and the temperature is increased by exotherm. The effect is also undesirable, in that it can be elevated above the temperature required for the reaction.

In addition, when the ratio of the volume of nitrogen is less than 8.5, it is not preferable in terms of stabilization of the reaction, and when it exceeds 9.5, it is not preferable in view of being more than necessary in consideration of being removed in the sulfidation step of the catalyst.

In the present invention, the metal catalyst may include one or more metals or oxides thereof selected from Groups 4 to 12 of the Periodic Table. Preferably, it is not particularly limited as long as it can be used as a composition of a catalyst that can utilize the active point of sulfur. For example, the metal catalyst may be at least one selected from the group consisting of nickel (Ni), cobalt (Co), tungsten (W), and molybdenum (Mo). Alternatively, the metal catalyst may be in the form of an oxide of one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), tungsten (W), and molybdenum (Mo).

Assuming that the active state of the metal catalyst is M _x S _n , the x and n are the number of each element such that the value of the oxidation number of all atoms becomes zero. At this time, the inactive state of the metal catalyst indicates that M _x S _m , m is a number from 0 to n-1, for example 0 or more than 0 to n-1 is an integer.

For example, nickel sulfide catalysts are NiS, Ni ⁰ and mixtures thereof in the inactivated catalyst state and NiS ₂ in the normal catalyst state. For cobalt sulfide catalysts it is Co ^{0 in the} deactivated catalyst state and CoS in the normal catalyst state. For tungsten sulfide catalysts, WS, W ⁰ S and mixtures thereof in the deactivated catalyst state and WS ₂ in the normal catalyst state. In the case of the molybdenum sulfide catalyst, MoS, Mo ^0, and a mixture thereof in the inactivated catalyst state, and MoS ₂ in the normal catalyst state.

Furthermore, it may be supported on a porous carrier to stably maintain the activity of the metal catalyst. The carrier is not particularly limited as long as it is a porous carrier capable of supporting the metal catalyst as the activity of the metal catalyst can be stably maintained. For example, it may be a carrier including at least one selected from the group consisting of silica, alumina and titania.

On the other hand, the sulfur compound in the step of producing hydrogen sulfide may be one or more selected from the group consisting of sulfide series (sulfide series), polysulfide series (polysulfide series) and mercaptan series (mercaptan series), the hydrogen sulfide ( The sulfur compound that can provide sulfur in the process of forming H ₂ S) is not particularly limited.

For example, DMDS (dimethyl disulfide, C ₂ H ₆ S ₂ ), DMS (dimethyl sulfide, C ₂ H ₆ S), DMSO (dimethyl sulfoxide, C ₂ H ₆ SO), TBPS (di-t-butyl polysulfide, Hydrogen sulfide may be prepared using one or more selected from the group consisting of C ₈ H ₁₈ S ₄ ), butyl mercaptan (C ₄ H ₁₀ S), and methyl mercaptan (CH ₄ S). Can be.

The step of converting the inert metal sulfide catalyst into the active metal sulfide catalyst is a step of regenerating the inert metal sulfide catalyst using hydrogen sulfide generated by the reaction of hydrogen or a mixed gas of hydrogen and nitrogen with the sulfur compound. Regenerating the catalyst may be carried out at a temperature range of 220 to 310 ℃, preferably reacting for a sufficient time for the sulfidation reaction to proceed completely in the temperature range.

More specifically, the catalyst for the sulfidation reaction may promote the exothermic reaction by the formation of methane by the reaction of the gas or carbon monoxide or carbon dioxide contained in the reactor with hydrogen. This exposes the catalyst to high temperatures and serious catalyst deactivation due to sintering makes it desirable to set a temperature range for supplying sulfur to the catalyst.

In order to prevent the above problems, the present invention can be carried out by setting the temperature range in the step of activating by supplying hydrogen sulfide to the inert metal sulfide catalyst. However, when a metal element including various electron valences is present in the metal catalyst and the electron valences are different, the temperature at which the sulfidation reaction proceeds on the surface of the catalyst may be different.

The metal element is most 4 ⁺ or 5 ⁺ E a and for the 4 ⁺ or a metal element with electrons of 5 ⁺ on the surface of the catalyst metal of the present invention in relation to the case where the temperature at which the sulfidation reaction proceeding different from the catalyst is generally The sulfidation reaction can be started at 220 ° C. During the sulfidation reaction, the temperature may be raised to about 270 ° C. due to the exothermic phenomenon. As described above, the catalyst of the present invention can generally actively proceed the sulfidation reaction on the surface of the catalyst at 220 to 270 ° C.

Furthermore, the catalyst also contains other valence metal elements and the sulfidation reaction using them proceeds at a slightly higher temperature than the metallic elements having valence 4 ⁺ or 5 ⁺ . Therefore, 100% of the deactivated sulfur can be activated by the sulfidation reaction at different temperature ranges.

On the other hand, it is preferable that the reaction is carried out for a sufficient time to proceed the sulfidation reaction completely, and the time of the sulfidation reaction is determined by the required amount of sulfur determined according to the amount of metal in the catalyst. In general, it is possible to determine whether the sulfidation reaction of the catalyst is completely performed by measuring the hydrogen sulfide slip at the rear end of the catalyst by the hydrogen sulfide analyzer or by measuring the hydrogen generation by the hydrogen analyzer. Therefore, the sulfidation reaction may be performed by the analyzer until the hydrogen sulfide or the hydrogen is not generated.

For example, as shown in FIG. 2, hydrogen sulfide is introduced into a metal catalyst and reacted at 200 to 230 ° C. for 2 to 3 hours at atmospheric pressure, and subsequently, the temperature of step A is increased to 2 to 2 ° C. at 270 to 310 ° C. It can be carried out in two steps including the step B, which is reacted for 3 hours.

In the case of performing in two steps as described above, it is possible not only to sulfide metals in various oxidation states, but also to soaking for stabilization of the catalyst (retention ripening while maintaining the initial reaction conditions to complete the desired reaction). There is an effect that can complete 100% sulphide.

On the other hand, prior to the step of supplying the sulfur compound to the inert metal sulfide catalyst, the step of heating to a temperature that can be converted to the active point of sulfur in the reaction of the obtained hydrogen sulfide and inert metal sulfide catalyst may be further performed. The heating is not particularly limited as long as it is a temperature range in which the produced hydrogen sulfide does not condense, and may be heated, for example, at 350-450 ° C.

When the hydrogen sulfide is supplied to the inert metal sulfide catalyst and the sulfidation reaction is completed, the hydrogen sulfide discharged without being used for regeneration of the catalyst among the supplied hydrogen sulfide may be supplied to the metal sulfide catalyst again. Therefore, by supplying the discharged hydrogen sulfide to the metal sulfide catalyst, it is possible to repeatedly supply a sufficient amount of sulfur necessary for the activity of the catalyst to the catalyst to prevent the inactive state of the catalyst.

As described above, the method for regenerating the metal sulfide catalyst of the present invention includes obtaining hydrogen sulfide from the reaction of hydrogen or a mixed gas of hydrogen and nitrogen with a sulfur compound, and reacting hydrogen sulfide with an inactivated metal sulfide catalyst to activate the metal catalyst. By including the step of maintaining the active state of the metal sulfide catalyst.

Example

1. Regeneration of inert metal sulfide catalysts

 (1) deactivation step

In order to regenerate the inert metal sulfide catalyst, the state of the inactivated molybdenum sulfide catalyst having lost the active point of sulfur was prepared as shown in Table 1 below. Table 1 if it is not H ₂ S is supplied to the molybdenum sulfide catalyst, maintaining the 10bar, and H ₂ 14% by volume, in 400 ℃ CO 25 vol%, CO ₂ 10% by volume, N ₂ 5 vol.% And H ₂ O Inert catalyst condition with 45% by volume is shown.

Inert metal catalyst Pressure: 10bar Temperature: 400 ^o C Gas hourly space velocity (GHSV): 5,000h ^-1 Supply: H ₂ 14%, CO 25%, CO ₂ 10%, N ₂ 5%, H ₂ O 46% and H ₂ S 0% Steam / carbon monoxide volume ratio: 1.8

(2) supply of hydrogen sulfide

As shown in Table 2, H ₂ 50ml / min and N ₂ 450ml / min for 2 hours at 220 ℃ at 1 atm and H ₂ 10% by volume and N ₂ 90% by volume of mixed gas and DMDS (dimethyl disulfide, C ₂ H ₆ S ₂ ) was reacted at 0.021 g / min, and hydrogen sulfide produced was supplied to the catalyst to carry out a sulfidation reaction. After the sulfidation reaction at 220 ° C. for 2 hours, the temperature was raised to 300 ^° C. under the same conditions as above, and the sulfidation reaction was performed for 2 hours.

After the sulfidation reaction, a process of removing nitrogen gas contained in the mixed gas at 25 ^° C. for 24 hours was performed.

DMDS Processing Conditions
Pressure: 1atm Temperature: 220 ~ 300 ^o C Supply: H ₂ 10%, N ₂ 90%, DMDS 0.021 g / min Remove: N ₂ 100%, 25 ^o C, 24h

(3) regeneration of inert metal sulfide catalysts

When the sulfur on the surface of the inert metal sulfide catalyst is regenerated, hydrogen sulfide is supplied to the metal sulfide catalyst including molybdenum which has lost the active point of S as shown in the following formulas (1) and (2), thereby providing a metal catalyst in an inactive state. It can be played.

Formula (1) 3H ₂ + C ₂ H ₆ S ₂ ? 2H ₂ S + 2CH ₄

(2) S activity loss catalyst (MoS or Mo0) + 2H ₂ S-> MoS ₂

2. Measurement of CO Conversion of Regenerated Metal Sulfide Catalysts

In order to confirm the activity of the metal sulfide catalyst regenerated by the regeneration method according to the present invention, maintaining the temperature of 400 ^o C at 10 bar and used for the CO conversion as shown in Table 3 H ₂ 13%, CO 25%, 10% CO ₂ , 3.2% N ₂ , 45% H ₂ O and 2000 ppm H ₂ S were fed. The results of measuring the CO conversion rate of the sour gas containing H ₂ , CO, and CO ₂ using a metal sulfide catalyst regenerated by hydrogen sulfide supplied under the above conditions are shown in FIG. 3.

CO conversion rate
Pressure: 10bar Temperature: 400 ^o C Gas hourly space velocity (GHSV): 5,000h ^-1 Supply: H ₂ 13%, CO 25%, CO ₂ 10%, N ₂ 3.2%, H ₂ O: 45%, H ₂ S: 2000 ppm Steam / carbon monoxide volume ratio: 1.8

Figure 3 shows the CO conversion (%) of the new gas in the molybdenum sulfide catalyst in an inactive state, and the CO conversion (%) of the molybdenum sulfide catalyst to restore the activity, according to an embodiment of the present invention Molybdenum catalyst was able to confirm the CO conversion rate (%) of more than 80%.

That is, when hydrogen sulfide was supplied to the surface of the inert metal catalyst, it was confirmed that the CO conversion (%) was restored to the same performance as the active state of the metal sulfide catalyst.

This is because when the deactivation of the catalyst proceeds while the concentration of sulfur of the deactivated metal sulfur compound decreases, the concentration of sulfur can be maintained in a high amount to maintain the activity of the catalyst. Therefore, as a conventional method for regenerating a metal sulfide catalyst, the catalyst may not be replaced by adopting a method of continuously supplying sulfur to the catalyst instead of removing and replacing the catalyst. That is, there is a difference in the method of regenerating the catalyst, and the procedure has a very simple effect.

Claims (9)

In the catalytic reaction using a metal sulfide catalyst,
Supplying hydrogen sulfide to the surface of the inert metal sulfide catalyst to convert it into an active metal sulfide catalyst,
The step of converting to the active metal sulfide catalyst is a step of reacting for 2 to 3 hours at 200 to 230 ° C. at atmospheric pressure and subsequently raising the temperature of step A and reacting for 2 to 3 hours at 270 to 310 ° C. A method of regenerating a metal sulfide catalyst, which is carried out in a step. The method of claim 1,
The metal sulfide catalyst regeneration method,
Hydrogen prior to feeding hydrogen sulfide; Or reacting a sulfur compound with a mixed gas of hydrogen and nitrogen to produce hydrogen sulfide. The method of claim 1,
The inert metal sulfide catalyst is M _x S _m , the active metal sulfide catalyst is M _x S _n , and x and n are the number of each element such that the value of oxidation number of all atoms is 0, where m is 0 To n-1, wherein the metal sulfide catalyst is regenerated. The method of claim 3, wherein
M is at least one selected from the group consisting of nickel (Ni), cobalt (Co), tungsten (W) and molybdenum (Mo). The method of claim 1,
The inert metal sulfide catalyst may be supported on a porous carrier including at least one selected from the group consisting of silica, aluminum, and titania. The method of claim 2,
The sulfur compound is DMDS (dimethyl disulfide, C ₂ H ₆ S ₂ ), DMS (dimethyl sulfide, C ₂ H ₆ S), DMSO (dimethyl sulfoxide, C ₂ H ₆ SO), N-butyl mercaptan (C ₄ H ₁₀ S), Methyl Mercaptan (CH ₄ S) and TBPS (di-t-butyl polysulfide, C ₈ H1 ₈ S ₄ ) is at least one selected from the group consisting of regeneration of metal sulfide catalyst. delete The method of claim 2,
Further comprising the step of heating the hydrogen sulfide supplied to the catalyst to 220 to 300 ℃ prior to the catalytic reaction using the metal sulfide catalyst, regeneration method of the metal sulfide catalyst. The method of claim 1,
And supplying the hydrogen sulfide to the inert metal sulfide catalyst includes supplying the hydrogen sulfide discharged without being used for regeneration of the catalyst among the supplied hydrogen sulfide to the metal sulfide catalyst.

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