JP2000015053A - Method for activation of active carbon fibrous desulfurizer and activated active carbon fibrous desulfurizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve effectively a removal activity of hydrogen sulfide by execution of baking treatment or nitric acid treatment of an active carbon fiber when a hydrogen sulfide desulfurizer comprising an active carbon fiber is activated. SOLUTION: An active carbon fiber is called also a carbon fiber, manufactured by carbonizing by heat treating in an innert gas of an organic fiber such as rayon, polyacrylonitrile, etc., or fiber prepared by spinning coal tar pitch and refined petroleum pitch, and PAN based active carbon fiber or pitch based active carbon fiber is preferably used. By executing burning treatment or nitric acid treatment of such an active carbon fiber, an activated active carbon fibrous hydrogen sulfide desulfurizer is obtained. Further, the baking treatment is executed within a rainge of about 550 to 850 deg.C in temperature. When this active carbon fibrous desulfurizer is used, hydrogen sulfide to be generated in living environment, or in cases of geothermal power generation, oil refining, natural gas refining, sewage disposal or the like, can be effectively removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for activating a hydrogen sulfide desulfurizing agent for activated carbon fibers and an activated carbon fiber hydrogen sulfide desulfurizing agent.

[0002]

2. Description of the Related Art Hydrogen sulfide is regulated as an air polluting odorant, but is generated during geothermal power generation, petroleum refining, natural gas refining, rayon production, sewage treatment, sludge treatment, waste disposal, and the like. 2. Description of the Related Art Conventionally, as a technique for removing hydrogen sulfide, a method of removing hydrogen sulfide by bringing a hydrogen sulfide-containing gas into contact with and adsorbing activated carbon at normal temperature has been known.
However, in this method, the amount of hydrogen sulfide adsorbed by the activated carbon is small, and frequent regeneration or replacement of the activated carbon is required.

[0003] Japanese Patent Application Laid-Open No. 8-281113 discloses, for example, an improved adsorption amount of trimethylamine, hydrogen sulfide, methyl mercaptan and the like. In this technique, a transition element and / or a compound thereof and a halogen or a halogen compound are added to an adsorbent such as activated carbon, hydrous magnesium silicate clay mineral, or silica gel, thereby exhibiting excellent deodorizing performance in a practical environment. And

There is also known a method in which a part of hydrogen sulfide in a hydrogen sulfide-containing gas is converted into sulfur dioxide by partial combustion, and then converted to sulfur at a high temperature using a catalyst and recovered. This method requires extensive equipment, such as the production of sulfur dioxide by partial combustion of hydrogen sulfide, followed by the conversion of hydrogen sulfide and the produced sulfur dioxide to sulfur by a conversion catalyst. When the concentration of hydrogen sulfide is low, there is a problem that it is difficult to remove hydrogen sulfide.

In addition, for example, Japanese Patent Application Laid-Open No. 8-299420
In No., activated carbon not only adsorbs deodorizing components, but also adsorbs bacteria, molds, bacteria, or protozoa that are harmful to the human body, which proliferates and returns to the environment where deodorization is required and contaminates. In order to solve this problem, at least one antibacterial agent selected from the group consisting of zinc metal and zinc oxide is deposited and adhered to the inner and outer surfaces of the activated carbon by an electrolytic method. However, this technique is specifically used for acetaldehyde (Example 1 in the publication), river water (Example 3), or air purification (Example 4). It is not used as a remover.

[0006]

SUMMARY OF THE INVENTION The present inventor has first considered that activated carbon fibers have excellent hydrogen sulfide adsorbing ability, and that this performance has excellent hydrogen sulfide adsorbing ability regardless of the presence or absence of oxygen. A method for removing hydrogen sulfide from a hydrogen sulfide-containing gas using an activated carbon fiber adsorbent has been previously proposed (Japanese Patent Application No. 9-212543). The present inventors have further experimented and pursued the adsorption characteristics of the activated carbon fiber, and found that the firing activity or the nitric acid treatment of the activated carbon fiber can effectively improve the activity of removing hydrogen sulfide.

That is, an object of the present invention is to provide a method for activating a hydrogen sulfide desulfurizing agent by calcination or nitric acid treatment of activated carbon fibers. It is an object of the present invention to provide a hydrogen sulfide desulfurizing agent comprising activated activated carbon fibers obtained by the treatment or nitric acid treatment.

[0008]

According to the present invention, there is provided (1) a method for activating a hydrogen sulfide desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are calcined. The present invention provides (2)
A method for activating a hydrogen sulfide desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are treated with nitric acid.

The present invention provides (3) a hydrogen sulfide desulfurizing agent comprising activated carbon fiber, wherein the activated carbon fiber is subjected to a calcination treatment, wherein the activated carbon fiber desulfurizing agent is provided. Further, the present invention provides (4) a hydrogen sulfide desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are treated with nitric acid.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Activated carbon fiber (Active C)
arbon Fiber: hereinafter appropriately referred to as ACF)
Is also called carbon fiber, and is produced by spinning organic fiber such as rayon or polyacrylonitrile, or fiber produced by spinning coal tar pitch or refined petroleum pitch in an inert gas and carbonizing. . In the present invention, any activated carbon fiber is used. Preferably, PAN-based activated carbon fiber (activated carbon fiber using polyacrylonitrile as a raw material for production) or pitch-based activated carbon fiber (coal tar pitch or petroleum pitch is spun) Activated carbon fiber using the fiber produced by the above process as a raw material.

According to the present invention, an activated carbon fiber hydrogen sulfide desulfurizing agent activated by calcination or nitric acid treatment of the activated carbon fiber can be obtained. The baking temperature is about 5
It is carried out in the range of 50 to 850 ° C, preferably in the range of about 600 ° C to about 800 ° C. In addition, hydrogen sulfide is regulated as an air pollution malodorous substance, but according to the activated carbon fiber desulfurizing agent activated in the present invention, it can be used in a living environment or in geothermal power generation, petroleum refining, natural gas refining, rayon production, Hydrogen sulfide generated during sewage treatment, sludge treatment, waste treatment, and the like can be very effectively removed.

In the present invention, (1) a gas containing hydrogen sulfide is brought into contact with the activated ACF desulfurizing agent according to the present invention. The gas may contain another gas. FIG. 1 shows an example of an embodiment of an apparatus for implementing the present invention. In FIG. 1, reference numeral 1 denotes a hydrogen sulfide-containing gas introduction pipe, 2 denotes an ACF packed bed (reaction pipe), and 3 denotes a treated gas discharge pipe. Hydrogen sulfide in the hydrogen sulfide-containing gas introduced from the introduction pipe 1 is adsorbed and removed by the ACF packed bed 2 or decomposed and adsorbed and discharged from the extraction pipe 3.

[0013]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it is needless to say that the present invention is not limited by these Examples. In this embodiment, a PAN-based ACF is described as an example, but the same applies to a pitch-based ACF.

Example 1 A PAN-based ACF was fired at each temperature for 1 hour in an argon stream. Table 1 shows the firing temperatures and the elemental analysis values. It also describes unfired PAN-based ACF.

[0015]

[Table 1]

The hydrogen sulfide removal activity by ACF in Table 1 was examined by a break-through test.
t). As the hydrogen sulfide-containing gas, a hydrogen sulfide-containing gas having an H ₂ S concentration of 100 ppm in nitrogen was used, and the reaction temperature was 30 ° C. An apparatus as shown in FIG. 1 was used. A reaction tube 2 is filled with each ACF, and a predetermined concentration of H ₂ S (concentration =
C ₀ ) was introduced and circulated, and H ₂ S (concentration = C) in the gas at the outlet of the reaction tube 2 was continuously measured and detected by GC-FPD (gas chromatograph equipped with a flame photometric detector).

The relative concentration (%) of hydrogen sulfide was calculated by the following equation (1) based on the concentration of H ₂ S at the inlet and outlet of the reaction tube 2 (C ₀ , C: see FIG. 1). In addition, the whole (1
The value obtained by subtracting the value of the relative concentration of hydrogen sulfide (%) calculated from the following formula (1) from the ratio (00%) corresponds to the trapping rate (conversion rate) of H ₂ S by the ACF.

[0018]

[Equation 1]

FIG. 2 shows the results of the breakthrough test. The sample fired at a temperature of 600 ° C. showed the highest activity, and the breakthrough start time was 2.7 hours (h). This is about twice as high as the breakthrough start time of the sample without calcination of 1.3 h, and the calcination treatment provided an excellent improvement effect on hydrogen sulfide removal ability. Further, according to an additional experiment on a sample having a firing temperature of about 600 ° C. to about 800 ° C., an improvement effect was observed in the range of about 550 to 850 ° C.

On the other hand, the breakthrough start time of the sample fired at 900 ° C. is 1.2 hours, and the hydrogen sulfide removing ability decreases in return. The sample fired at 1100 ° C. has the hydrogen sulfide removing ability from the beginning of the reaction. It is not allowed. As shown in Table 1, the higher the firing temperature, the lower the oxygen content.
It is understood that the carbonyl group contained in CF is released as CO or CO ₂ . Considering this together with the result of FIG. 2, the firing process at a temperature of 600 to 800 ° C.
It is presumed that the balance between the degree of carbonization and the increase in the number of active sites resulting from CO and CO ₂ elimination was most balanced.

Example 2 In Example 1, a hydrogen sulfide-containing gas in nitrogen was used. In Example 2, hydrogen sulfide-containing gas in air was used as the hydrogen sulfide-containing gas. The hydrogen scavenging activity was determined by a breakthrough test. H ₂ S concentration 100 in air as hydrogen sulfide containing gas
The same operation as in Example 1 was carried out except that a gas containing hydrogen sulfide at ppm was used. FIG. 3 shows the results of the breakthrough test.

The sample having a calcination temperature of 600 ° C. showed the highest activity, and the breakthrough start time was 10.5 hours. In comparison with the breakthrough start time of the sample without firing of 6.3 h, about 1.
7 times, and thus an excellent improvement effect on hydrogen sulfide removal ability was obtained even in air. The breakthrough start time of the sample at a sintering temperature of 800 ° C. was 10.2 h, and the
It shows a high activity corresponding to the sample at ° C. Further, according to an additional experiment on a sample having a firing temperature of about 600 ° C. to about 800 ° C., an improvement effect was observed in the range of about 550 to 850 ° C. On the other hand, the breakthrough start time of the sample fired at 900 ° C. is 1.6 h, and the hydrogen sulfide removing ability decreases in return. The sample fired at 1100 ° C. shows the hydrogen sulfide removing ability from the beginning of the reaction. I couldn't.

Example 3 PAN ACF 3.000 g
Was immersed in a 12.2 wt% aqueous solution of nitric acid for 72 hours at room temperature. Next, the ACF was taken out, and water was evaporated at a temperature of 70 ° C. using an evaporator. Then, it is baked at 200 ° C. for 1 hour in a nitrogen stream, and the remaining nitric acid is
Removed as x. Table 2 shows the elemental analysis values.

[0024]

[Table 2]

In the same manner as in Example 1, AC
The activity of removing hydrogen sulfide by F was examined by a breakthrough test.
FIG. 4 shows the results of the breakthrough test. As shown in the figure, the breakthrough start time of the ACF sample without nitric acid treatment was 1.
3 h. In contrast, the breakthrough start time of the nitric acid-treated ACF sample was 2.1 h. The difference is 0.8h
This is an excellent improvement effect on hydrogen sulfide removal performance.

Regarding the cause of activation of the ACF by the baking treatment or the nitric acid treatment, untreated ACF and baking
For CF and nitric acid-treated ACF, the TPD (Temperature Program)
(ed Desorption) measurement was performed. as a result,
Although those untreated were slightly observed residual as H ₂ S, both in the firing process or nitric acid treated ACF H ₂
No residual S was observed, and at the same time, residual SO _{3 at} around 250 ° C., particularly SO _{2 at} around 90 ° C. was observed with nitric acid-treated ACF. S is obtained by nitric acid treatment in addition to SO ₂
Adsorption as O ₃ is also observed.
The amount of adsorption was also large, such as ppm. From these facts, it is considered that the oxidation rate of H ₂ S is very high in the calcined or nitric acid-treated ACF, and it is considered that the influence of the carbonyl group is greatly involved in this oxidation.

[0027]

According to the present invention, an activated carbon fiber hydrogen sulfide desulfurizing agent which is further activated as a hydrogen sulfide desulfurizing agent by subjecting the activated carbon fiber to a baking treatment or a nitric acid treatment can be obtained. This makes it possible to more effectively remove hydrogen sulfide from various gases containing hydrogen sulfide.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of an apparatus for implementing the present invention.

FIG. 2 is a diagram showing the results of a breakthrough test in Example 1.

FIG. 3 is a diagram showing the results of a breakthrough test in Example 2.

FIG. 4 is a diagram showing the results of a breakthrough test in Example 3.

[Explanation of symbols]

 1 Hydrogen sulfide containing gas introduction pipe 2 Activated carbon fiber packed bed (reaction pipe)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B01J 20/34 B01D 53/34 ZAB F term (reference) 4D002 AA03 AB02 AC10 BA04 CA07 DA44 EA06 EA07 EA08 GA01 GA02 GB02 GB11 HA03 4D012 BA03 CA09 CD05 CD10 CE02 CE03 CF05 CF08 CG04 CK05 4G066 AA05B AD20B BA16 CA24 DA02 DA03 DA05 GA01 GA11 GA32

Claims (7)

[Claims] 1. A method for activating a hydrogen sulfide desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are calcined. 2. The method according to claim 1, wherein the firing temperature is 550 to 850 ° C. 3. A method for activating a hydrogen sulfide desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are treated with nitric acid. 4. The activated carbon fiber desulfurizing agent activation method according to claim 1, wherein the activated carbon fiber is a PAN-based activated carbon fiber or a pitch-based activated carbon fiber. 5. An activated carbon fiber desulfurizing agent comprising an activated carbon fiber, wherein the activated carbon fiber is subjected to a calcination treatment. 6. An activated carbon fiber desulfurizing agent comprising activated carbon fibers, wherein the activated carbon fibers are treated with nitric acid. 7. The activated carbon fiber desulfurizing agent according to claim 5, wherein the activated carbon fiber is a PAN-based activated carbon fiber or a pitch-based activated carbon fiber.