KR100423095B1 - Method for preparing activated carbon-supported fibers using the inorganic fiber materials - Google Patents

Abstract

The present invention relates to a method for producing activated carbon-based fibers used as adsorbents, catalyst carriers and catalysts through a process of activating a cured resin based on inorganic fibers such as glass fibers or silica fibers and treated with a chemical activator. As an activated carbon body fiber produced by the method comprising the step of activating a chemical activator-containing resin cured product formed on an inorganic fiber base material in an inert atmosphere according to the present invention, the activated carbon body fibers are superior to the activated carbon body fibers produced by the conventional method. It has the advantage of low manufacturing cost with characteristics.

Description

Method for producing activated carbon fiber using inorganic fiber {METHOD FOR PREPARING ACTIVATED CARBON-SUPPORTED FIBERS USING THE INORGANIC FIBER MATERIALS}

The present invention relates to a method for producing activated carbon fibers, and more particularly, using an inorganic fiber such as glass fiber or silica fiber as a base material and activating a cured resin treated with a chemical activator under an inert atmosphere. The present invention relates to a catalyst carrier and a method for producing activated carbon fibers used as a catalyst.

In general, the activated carbon fiber has the advantage that the fine pores are well developed compared to the activated carbon, the adsorption and desorption rate is fast and uniform pore structure.

Conventional activated carbon fibers have been prepared by activating carbon fibers obtained from polymer raw materials such as polyacrylonitrile, pitch and phenol at a high temperature of 900 to 1,500 ° C. using an oxidizing agent. Is open to the public. Specifically, U. S. Patent No. 4,285, 831 discloses a method for producing polyacrylonitrile-based activated carbon fibers with improved mechanical strength by giving stretching to a certain limit causing crystallization of carbon fibers. However, this method has a disadvantage in that the universality is limited and the specific surface area is not large because the limit of the stretching force is determined based on the change of the oxygen content in the fiber. In addition, Japanese Patent Application Laid-Open No. 4-126826 discloses a method of producing activated carbon fibers by activating at 750 to 1,100 ° C using a pitch-based material, and Korean Patent Publication No. 97-11056 discloses a polyacrylonitrile system. Disclosed is a method of producing activated carbon fibers by using carbon fibers as a raw material and activating them in a temperature range of 600 to 800 ° C. However, the activated carbon fiber prepared in this way, the stabilization step; Carbonization step; And through the activation step, etc., the manufacturing process is complicated, and the price of various carbon fibers used as intermediate materials has been limited in terms of price. In addition, the method has a disadvantage in that the carbon yield is low and mechanical properties such as strength and abrasion resistance are poor, since the carbon must be accompanied by vaporization of fixed carbon in the carbon fiber in order to obtain well-developed activated carbon fiber.

Therefore, in order to compensate for the disadvantages of the method of manufacturing activated carbon fibers, a method of manufacturing activated carbon fibers by impregnating pitch or phenol resin into glass fibers, which are inexpensive fiber materials than carbon fibers, has been attempted (US Patent No. 5,834,114, Korean Patent). Korean Patent Publication No. 1999-52869), which has advantages in that mechanical properties are improved by using fiber materials, and inexpensive activated carbon fibers can be manufactured by using raw materials having low cost. However, the activated carbon fiber produced according to the above method has a disadvantage in that the manufacturing cost is still high due to the small specific surface area which determines the adsorption capacity or by following the existing manufacturing process including the physical carbonization step, thereby improving the specific surface area and improving the manufacturing process. There is an urgent need for development of a process for producing simplified activated carbon fibers.

Accordingly, an object of the present invention is to provide a method for producing activated carbon-based fibers having low cost using raw materials having low porosity and well developed pores that influence the adsorption capacity while using a simple manufacturing process. The present invention has been completed by knowing that such a purpose can be achieved by activating a cured resin product treated with a chemical activator under an inert atmosphere.

1 is a block diagram showing a manufacturing process of activated carbon fiber according to Example 1 of the present invention,

Figure 2 is a block diagram showing a manufacturing process of activated carbon fiber according to Example 2 of the present invention.

In order to achieve the above object, in the present invention, a method for producing activated carbon fiber comprising the step of activating the cured drug activator-containing resin formed on the inorganic fiber base material in an inert atmosphere, more specifically, on the inorganic fiber base material Impregnating and then curing the resin; Treating the obtained cured product (green body, GB) in an aqueous drug activator solution; And activating the resultant in an inert atmosphere (method 1), or treating the resin with a chemical activator; Impregnating the obtained resin onto an inorganic fiber matrix and then curing; And activating the obtained cured product in an inert atmosphere (method 2).

Hereinafter, the present invention will be described in detail.

A feature of the method of the present invention is to activate a cured resin treated with a chemical activator based on an inorganic fiber such as glass fiber or silica fiber, and according to the method of the present invention, an increase in specific surface area and low production cost There is provided a manufacturing method for producing a fiber, the production process of which is simplified.

The process of the invention is carried out as in the process shown in FIG. 1 or FIG. 2.

Treatment with the chemical activator in the present invention includes impregnating (adhering) the cured resin or the like into the chemical activator aqueous solution or filling the chemical activator with the resin.

As the inorganic fiber material used in the present invention, glass fibers and silica fibers which are inexpensive, widely used and inert are preferred.

As the resin used in the present invention, resol type phenol resins and novolac type phenol resins are preferable, and the crosslinked structures they have after curing are effective for forming a uniform pore structure.

Chemical activators used in the present invention include oxalic acid (H ₂ C ₂ O ₄ ), nitric acid (HNO ₃ ), sulfuric acid (H ₂ SO ₄ ), ammonium nitrate (NH ₄ NO ₃ ), ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), an aqueous solution of an acid selected from the group consisting of sodium sulfate (Na ₂ SO ₄ ), sodium nitrate (NaNO ₃ ), phosphoric acid (H ₃ PO ₄ ) and ammonium oxalate ((NH ₄ ) ₂ C ₂ O ₄ ), Lewis Zinc chloride (ZnCl ₂ ), or potassium hydroxide (KOH), potassium carbonate (K ₂ CO ₃ ), sodium hydroxide (NaOH), ammonium hydroxide (NH ₄ OH), sodium chloride (NaCl), sodium hypochlorite (NaOCl), and Preference is given to aqueous solutions of salts selected from the group consisting of ammonium bifluoride (NH ₄ FHF). The activator acts as a dehydrogenating agent upon activation of carbon, which not only forms carbon-carbon crosslinking in the base resin, but also inhibits vaporization and contraction of fixed carbon, thereby enhancing carbon yield and micropore development. Let's do it.

In the method 1, the drug activator is preferably used at 25 to 300% by weight based on the weight of the resin. If the weight ratio is less than 25% by weight, it is not preferable because the specific surface area of the activated carbon fiber obtained after activation is low, and if it exceeds 300% by weight, carbon yield becomes active due to active vaporization of carbon during activation.

Meanwhile, in the method 2, the drug activator is preferably 10 to 200% by weight based on the weight of the resin. When the weight ratio is less than 10% by weight, the specific surface area of the activated carbon fiber is low, and when it exceeds 200% by weight, it is not preferable because the content of the resin is low and the impregnation is poor due to the viscosity increase.

In the drug activator impregnation treatment step of Method 1, the treatment temperature is preferably 5 ° C to 120 ° C, and the treatment time is 0.5 to 3 hours.

In the drug activator filling step of the method 2, when the drug activator is in a solid phase, any solvent can be used as long as it can dissolve the resin and the drug activator at the same time as ethyl alcohol.

Activation of the cured product after the curing step is preferably performed at a temperature of 500 to 850 ℃. If the activation temperature is less than 500 ° C., complete carbonization and activation may not be achieved due to the pyrolysis mechanism of the cured product. If the activation temperature is higher than 850 ° C., the shape of the fiber collapses due to melting of the matrix fiber, which is not preferable.

In the activation step, the temperature increase rate is preferably 1 to 120 ℃ / min. If the temperature increase rate is less than 1 ° C / min, productivity is lowered, and if the temperature rise rate exceeds 120 ° C / min, not only does not significantly affect the improvement of physical properties, but also the carbon yield falls.

In the activation step, the activation time is preferably 10 minutes to 5 hours. Activated carbon fiber having a good specific surface area is obtained in the case of activating for a short time after reaching the activation temperature, that is, for 10 minutes or more and cooling, but in case of exceeding 5 hours, there is no effect of enhancing physical properties and also in terms of economic efficiency. Not desirable

The following examples of the present invention are intended to more clearly understand the present invention and are for illustrative purposes only and are not intended to limit the scope of the invention.

Example 1

Activated carbon body fibers were prepared by the procedure shown in FIG. 1. Resol type phenol resins and zinc chloride (ZnCl ₂ ) were used as starting materials and drug activators, respectively. First, a resin solution containing 10 g of a resol-type phenolic resin (obtained from Gangnam Hwaseong Co., Ltd.) was poured into a glass fiber of 391 cm ² , impregnated with a ruler, and then impregnated with a ruler. 2 hours, 30 minutes at 150 ° C., 30 minutes at 180 ° C. The cured product thus obtained was added to a 100 ml aqueous solution containing 25% by weight of zinc chloride based on the weight of the phenol resin and then impregnated at 25 ° C. for 30 minutes. The cured product impregnated with zinc chloride was dried at about 110 ° C. for 24 hours and then activated in a furnace filled with an inert gas. At this time, the activation temperature was 500 ℃, the temperature increase rate was 1 ℃ / min and after reaching the activation temperature was activated for 1 hour and then cooled under an inert gas atmosphere. In order to remove residual organic matters and the like from the obtained carbonaceous fiber, the activated carbon fiber was washed with 0.5N HCl aqueous solution at 85 ° C. for 1 hour, then washed several times with distilled water and dried at 100 ° C. for 24 hours. The final activated carbon fiber was prepared.

Example 2

Activated carbon body fibers were prepared by the procedure shown in FIG. 2. Novolak-type phenolic resins and potassium hydroxide (KOH) were used as starting materials and drug activators, respectively. First, 10 g of novolac-type phenolic resin (obtained from Gangnam Hwaseong Co., Ltd.) was added to 30 ml of ethyl alcohol, dissolved at 70 ° C. for 30 minutes, and then potassium hydroxide was added to 50% by weight based on the weight of phenolic resin and then again. After mixing for 15 minutes, 1 g of hexamethylene tetramine (HMTA) was added thereto, followed by mixing for 15 minutes to prepare a resin solution for impregnation. To obtain a cured product, first, the resin solution is poured into 391 cm ² glass fibers, and then impregnated evenly using a ruler, followed by curing cycle for 30 minutes at 100 ° C, 2 hours at 125 ° C, 30 minutes at 150 ° C, and 180 ° C. Cured for 30 minutes. The cured product filled with potassium hydroxide was dried at about 110 ° C. for 24 hours and then activated in a furnace filled with an inert gas. At this time, the activation temperature was 700 ℃, the temperature increase rate was 10 ℃ / min, after activating for 2 hours after reaching the activation temperature was cooled under an inert gas atmosphere. In order to remove residual organic matters and the like from the obtained carbonaceous fiber, the activated carbon fiber was washed with 0.5N HCl aqueous solution at 85 ° C. for 1 hour, then washed several times with distilled water and dried at 100 ° C. for 24 hours. The final activated carbon fiber was prepared.

[Examples 3 to 9]

The final activated carbon fiber was prepared by the same procedure as in Example 1, except that the type of resin, the type and weight ratio of the drug activator, and the activation conditions were performed as described in Table 1 below.

[Examples 10 to 17]

The final activated carbon fiber was prepared by the same procedure as in Example 2, except that the type of resin, the type and weight ratio of the drug activator, and the activation conditions were performed as described in Table 1 below.

[Comparative Example]

As a comparative example, the activated carbon body fibers were prepared by the same procedure as in Example 1 except that the chemical activator was not activated and subjected to the carbonization process of the physical activation method.

Specific surface area, total pore volume, carbon yield and pure specific surface area of the activated carbon fibers prepared as in Examples 1 to 17 and Comparative Examples were measured as follows, and the results are shown in Table 2 as the average of each measured value. Indicated.

1. Resin: known weight ratio

In order to determine the weight ratio of the resin based on the weight of the base material of each sample, a sample having a known weight was placed in a crucible and then burned for 4 hours in a furnace under an air atmosphere to remove the resin. At this time, heating temperature was 850 degreeC and the temperature increase rate was 10 degreeC / min. At this time, the content of the resin was determined from the amount of the base material remaining in the crucible.

2. BET specific surface area measurement method (m ² / g)

About 0.1 to 0.5 g of the sample was taken and each sample was outgassed for about 9 to 12 hours until the residual pressure in the sample was less than 10 ^-3 mmHg at 573K, and then nitrogen at 77K due to the increase in the relative pressure. The amount of adsorption of the gas was measured. At this time, the slope of the straight line was obtained at a portion of P / P ₀ (where P is partial pressure and P ₀ is saturated steam pressure) of about 0.05 to 0.2. From this, the BET specific surface area was obtained.

3. Total pore volume (cc / g)

When adsorbed with nitrogen at 77K, the adsorption amount of nitrogen adsorbed at a relative pressure of about 0.995 is V _max (unit: cc) divided by 22,400cc and converted to the number of moles adsorbed. Obtained by multiplying 34.67 cc.

4. Carbon yield (% by weight)

The carbon yield of the activated carbon fiber obtained from the present invention was calculated as follows:

Carbon yield = [{( W ₁ × R ) -W _2} / ( W ₁ × R )] × 100

Here, W ₁ is the mass of the cured product, W ₂ is the weight loss after activation, and R is the content ratio of the resin in the cured product.

5. Pure BET Specific Surface Area (m ² / g)

Since the BET specific surface area of 2. is included in the mass of the matrix, the specific surface area of the pure resin obtained from the present invention was calculated and calculated as follows:

Pure BET Specific Surface Area = [(100 / R ) × A ]

Where R is the resin weight ratio and A is the BET specific surface area including the known mass.

Resin: Base Weight Ratio BET specific surface area (m ² / g) Pore Volume (cc / g) Carbon yield (%) Pure BET Specific Surface Area (m ² / g) Example 1 71:29 127 0.07 70.1 438 Example 2 68:32 229 0.1 70.3 716 Example 3 70:30 132 0.07 65.3 440 Example 4 70:30 146 0.08 55.2 487 Example 5 69:31 177 0.09 49.8 571 Example 6 70:30 135 0.07 69.7 450 Example 7 70:30 211 0.1 58.7 703 Example 8 71:29 235 0.11 53.5 810 Example 9 70:30 140 0.07 67.2 467 Example 10 72:28 198 0.08 70.3 707 Example 11 70:30 223 0.09 68.8 763 Example 12 71:29 241 0.11 66.5 831 Example 13 71:29 264 0.11 66.0 910 Example 14 71:29 316 0.14 63.6 1090 Example 15 71:29 340 0.16 62.9 1172 Example 16 70:30 378 0.17 62.0 1303 Example 17 68:32 464 0.20 60.3 1450 Comparative example 71:29 50 0.08 52 172

As shown in Table 2, the activated carbon fiber prepared in Examples 1 to 17 has a larger specific surface area, higher pore volume, and higher carbon yield than the activated carbon fiber of the comparative example which was subjected to a carbonization process without being treated with a chemical activator. It can be seen that this is excellent.

According to the present invention, activated carbon-based fibers prepared by using inorganic fibers as a base material and activating a resin cured product treated with a chemical activator have well developed pore properties, are not subjected to a carbonization process, and are used at relatively low temperatures. By chemical activation, the carbon yield is high and the manufacturing cost is low.

Claims (13)

A method of producing an activated carbon body fiber comprising the step of activating a chemical activator-containing resin cured product formed on an inorganic fiber base material in an inert atmosphere. The method of claim 1, Curing the resin cured product by impregnating a resin on an inorganic fiber matrix and then curing the resin; And treating the obtained cured product in an aqueous chemical activator solution. The method of claim 1, Treating the resin with a chemical activator by the cured resin; And impregnating the obtained resin onto an inorganic fiber matrix and then curing. The method according to any one of claims 1 to 3, The inorganic fiber matrix is glass fiber or silica fiber. The method according to any one of claims 1 to 3, The resin is a resol type phenol resin or novolak type phenol resin. The method according to any one of claims 1 to 3, The drug activator is an acid selected from the group consisting of oxalic acid, nitric acid, sulfuric acid, ammonium nitrate, ammonium sulfate, sodium sulfate, sodium nitrate, phosphoric acid, ammonium oxalate and zinc chloride, or potassium hydroxide, potassium carbonate, sodium hydroxide, ammonium hydroxide, sodium chloride, hypochlorous acid A salt selected from the group consisting of sodium chlorate and ammonium bifluoride. The method of claim 2, Weight of the drug activator is 25 to 300% by weight based on the weight of the resin. The method of claim 3, wherein Weight of the drug activator is 10 to 200% by weight based on the weight of the resin. The method according to any one of claims 1 to 3, The activation temperature is 500 to 850 ° C. and the temperature increase rate is 1 to 120 ° C./min. The method according to any one of claims 1 to 3, The activation time is 10 minutes to 5 hours. The method of claim 2, Wherein the drug activator treatment temperature is 5 to 120 ° C. The method of claim 2, The drug activator treatment time is 0.5 to 3 hours. The method according to any one of claims 1 to 3, The method further comprises pickling and drying the resultant obtained in the activation step.