JPH0471435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for high-level desulfurization of gas containing sulfur compounds. The method of the present invention includes steam reforming,
It is particularly suitable for desulfurization of various gases used in methanation, hydrogenation, etc.

Prior Art Conventionally, for example, when performing steam reforming of hydrocarbons, as shown in FIG. Thereafter, adsorption desulfurization using ZnO or the like is carried out in an adsorption desulfurization device 27, and the thus purified hydrocarbons are passed through a line 29 and used as a raw material in the subsequent process. However, in such a desulfurization method, if the activity of the catalyst in the hydrodesulfurization equipment 23 decreases, organic sulfur compounds such as thiophene may come into direct contact with the catalyst for subsequent steam reforming of hydrocarbons. There is a risk that the catalyst will become unusable. In addition, the adsorption desulfurization device 27
As is clear from the equilibrium equation, a non-negligible amount of H ₂ S slip is observed when the temperature is high or when the P _{H 2 O} is large. Furthermore, according to the desulfurization method of the type shown in Figure 2, it is practically difficult to reduce the H ₂ S concentration in the gas to 0.02 ppm or less even if all reactions are carried out normally. . Therefore, due to the current state of the technology, which has become more susceptible to the negative effects of H ₂ S due to the use of more highly active catalysts, a new method that can easily perform higher-order desulfurization has been developed. The practical application of this method is eagerly awaited.

Composition of the Invention As a result of various studies in view of the current state of the technology as described above, the present inventor has discovered that when desulfurizing a sulfur compound-containing gas, after performing hydrogen desulfurization and adsorption desulfurization, a copper-based desulfurization agent is used. When performing adsorption desulfurization, reduce the concentration of sulfur compounds in the gas from 0.1ppm to 1ppb.
It has been found that this can be reduced to a certain extent. That is, the present invention provides a gas containing sulfur compound, which is characterized in that the gas containing a sulfur compound is subjected to hydrodesulfurization treatment and adsorption desulfurization treatment using a zinc-based desulfurization agent, and then subjected to adsorption desulfurization treatment using a copper-based desulfurization agent. Concerning a high-order desulfurization method.

The copper-based desulfurization agent used in the present invention exhibits a particularly excellent sulfur compound adsorption effect when the sulfur compound concentration in the gas is about 1 ppm to 1 ppb and when the gas contains an organic sulfur compound such as thiophene. Therefore, it is preferable to reduce the concentration of sulfur compounds in the gas to the above range by hydrodesulfurization and adsorption desulfurization using a zinc desulfurization agent, and then perform adsorption treatment using a copper desulfurization agent.

EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described in detail with reference to a flowchart according to an embodiment of the present invention shown in the drawings.

In FIG. 1, a gas containing sulfur compounds is supplied to a hydrodesulfurization apparatus 3 via a line 1. The conditions for hydrodesulfurization are not particularly different from those in known hydrodesulfurization, such as
Temperature 350 in the presence of NiMoS-based, CoMoS-based catalysts, etc.
The conditions of approximately 400° C., pressure of approximately 10 kg/cm ² G, and SV of approximately 3000 are adopted.

The gas that has undergone hydrodesulfurization is sent to an adsorption desulfurization device 7 through a line 5. The conditions for adsorption desulfurization are also
Although there is no particular difference from that of known technology, in order to maximize the sulfur compound adsorption effect by the subsequent copper-based adsorbent, it is desirable that the sulfur compound concentration in the gas is approximately 1 to 0.1 ppm. Therefore, the temperature in the presence of zinc desulfurization agent is about 350 to 400℃,
It is preferable to adopt conditions of a pressure of about 10 kg/cm ² ·G and an SV of about 1000, but other conditions can of course be adopted.

The gas whose concentration of sulfur compounds has been reduced to about 1 to 0.1 ppm is supplied via line 9 to a second adsorption desulfurization device 11 that uses a copper-based desulfurization agent.
Examples of the copper-based desulfurization agent include those containing 5% or more of copper or copper oxide, and optionally containing at least one of zinc oxide, alumina, silica, and the like. The conditions for adsorption are a temperature of about 200 to 250℃,
Pressure 1~100Kg/ ^cm2・G, P _H2O 0~20Kg/
It is preferable to set it to about cm ² ·G and SV about 1000.
The copper desulfurization agent used has a sulfur compound concentration of 1 to
Since it exhibits a particularly remarkable sulfur compound adsorption effect in the 0.01 ppm range, there is no leakage of H ₂ S. Furthermore, since organic sulfur compounds can also be adsorbed, high-level desulfurization is possible even when the catalyst in the hydrodesulfurization device 3 deteriorates and hydrogenation of organic sulfur compounds is not performed sufficiently.

The copper-based desulfurization agent used in the present invention is produced, for example, as follows.

It may be prepared by adding an auxiliary agent to a precipitate obtained by a coprecipitation method from a solution containing Cu and Zn components, and using a method similar to a general method for producing a low-temperature shift catalyst, such as tableting and calcination.

Effects of the Invention According to the present invention, the following effects are achieved.

(1) Calculate the concentration of sulfur compounds contained in the gas.
It can be easily reduced to 0.1ppm or less, up to about 1ppb.

(2) Therefore, poisoning of the catalyst in subsequent steam reforming, methanation, hydrogenolysis, etc. can be prevented, and the life of the catalyst can be greatly extended.

Examples Examples will be shown below to further clarify the features of the present invention.

Example 1 After hydrogenolyzing coke oven gas with a sulfur compound content of 150 ppm (as S) in the presence of a NiMo catalyst under conditions of temperature 380°C, pressure 10 Kg/cm ² G, and SV 3000. , in contact with Zno desulfurization agent,
Desulfurized. The concentration of sulfur compounds in the obtained gas was approximately 5 mg·S/Nm ³ (average over 1000 hours).

The primary purified gas thus obtained was 400/hr.
The mixture was supplied to an adsorption desulfurization device (catalyst layer length: 10 cm) filled with 50 g of a desulfurization catalyst consisting of 30% CuO and 70% ZnO, and desulfurization was carried out under conditions of a temperature of 180 to 250°C and a pressure of 8 kg/cm ² ·G.

The sulfur compound concentration in the final purified gas was always less than 0.01 mg·S/Nm ³ .

Example 2 A mixture consisting of naphtha and H ₂ (H ₂ /naphtha molar ratio 0.3, sulfur compound content 100 ppm) was heated in the presence of a NiMo catalyst at a temperature of 380°C and a pressure of 10
After hydrogenolysis under the conditions of Kg/cm ²・G and SV3000,
Desulfurization was performed by contacting with a Zno desulfurization agent. The concentration of sulfur compounds in the purified gas obtained was approximately 5 mg・S/
Nm ³ (average over 1000 hours).

The purified gas thus obtained 400/hr was converted into CuO30
%-ZnO 70% desulfurization catalyst (catalyst layer length 10 cm), and the temperature was approx.
Desulfurization was carried out under the conditions of 200°C and a pressure of 8 kg/cm ² ·G.

The sulfur compound concentration in the final purified gas was always less than 0.01 mg·S/Nm ³ .

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an example of an embodiment of the present invention. FIG. 2 is a flowchart showing an example of gas purification by a conventional method. 3...Hydrodesulfurization equipment, 7...Adsorption desulfurization equipment, 1
1... Adsorption desulfurization equipment, 23... Hydrodesulfurization equipment, 2
7...Adsorption desulfurization equipment.

Claims (1)

[Claims] 1 After subjecting the sulfur compound-containing gas to hydrodesulfurization treatment and adsorption desulfurization treatment using a zinc-based desulfurization agent,
A method for high-level desulfurization of gas, characterized by subjecting it to adsorption desulfurization treatment using a copper-based desulfurization agent.