HIGH-PERFORMANCE SPHERICAL ACTIVATED CARBON, PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

A high-performance spherical activated carbon has a specific surface area of less than 1250 m.sup.2/g as well as desirable physical or mechanical properties. It can be prepared using spherical polymeric particles. The spherical activated carbon can be used as adsorbents.

Claims

1. A spherical activated carbon, wherein the specific surface area B of the activated carbon is less than 1250 m.sup.2/g; preferably, 600 m.sup.2/gB1200 m.sup.2/g; for example, 700 m.sup.2/gB1100 m.sup.2/g.

2. The spherical activated carbon according to claim 1, wherein the median particle size D.sub.50 of the spherical activated carbon can be 0.2-1.5 mm, such as 0.5-1.3 mm, for example 0.7-1.2 mm; preferably, the median pore size of the spherical activated carbon can be 1-4 nm, such as 1.5-3.8 nm, for example 1.8-3.8 nm; preferably, the compressive strength of the spherical activated carbon can be 10-300N, such as 40-150N, for example 50-140N, for example 50-130 N; preferably, the cracking rate of the spherical activated carbon can be less than 10.0%, such as 1.0-10.0%, for example 1.5-6.0%, preferably less than 5.0%, for example 3.0-5.0%.

3. The spherical activated carbon according to claim 1, wherein the iodine adsorption value of the spherical activated carbon is 400-1100 mg/g, preferably 500-1000 mg/g, for example 600-950 mg/g; preferably, the bulk density of the spherical activated carbon can be 300-1000 g/L, preferably 400-800 g/L, for example 450-700 g/L.

4. The spherical activated carbon according to claim 1, wherein the raw material for preparing the spherical activated carbon is a spherical polymer.

5. A preparation method of the spherical activated carbon according to claim 1, comprising the following steps: 1) carbonizing the spherical polymer; 2) activating the product obtained in step 1).

6. The preparation method according to claim 5, wherein the carbonization temperature of step 1) can be 100-950 C, for example 150-900 C., such as 300-850 C.; the carbonization time is 30 minutes to 10 hours, for example 1 to 8 hours, such as 2 to 6 hours; the activation of step 2) can comprise a first activation step and a second activation step; the temperature of the first activation step is 700-1300 C., for example 800-1200 C., such as 850-950 C.; the time of the first activation step is 1-24 hours, for example 5-15 hours, such as 6-12 hours; preferably, the atmosphere of the first activation step comprises water vapor, in particular a mixture of water vapor and an inert gas, preferably a mixture of water vapor and nitrogen, or the atmosphere is composed of the above gases; preferably, the volume ratio (flow rate ratio) of nitrogen and water vapor is 3:1 or more, for example 4:1-10:1, preferably 4:1-8:1; the temperature of the second activation step is 700-1300 C., preferably 800-1200 C., for example 850-950 C.; the time of the second activation step is 1-10 hours, for example 3-8 hours; preferably, the atmosphere of the second activation step comprises CO.sub.2, for example CO.sub.2 or a mixture of CO.sub.2 and an inert gas, for example a mixture of CO.sub.2 and nitrogen; preferably, where the second activation atmosphere comprises a mixture of nitrogen and CO.sub.2, the volume ratio (flow rate ratio) of nitrogen and CO.sub.2 can be 10:1-1:10, for example 10:1-2:1, such as 8:1-4:1, for example 3:1-2:1.

7. Use of the spherical activated carbon according to claim 1 as an adsorbent; preferably, the spherical activated carbon is used to adsorb harmful gases, for example one or more selected from the group consisting of CO, H.sub.2S, HCl, SO.sub.2 and NOx; preferably, the spherical activated carbon is used in food industry for the preparation and/or decolorization of a food.

8. Use of the spherical activated carbon according to claim 1 in the preparation of drugs.

9. An adsorbent, comprising the spherical activated carbon according to claim 1.

10. A protective clothing, comprising the above spherical activated carbon according to claim 1.

Description

DETAILED DESCRIPTION

[0077] The present disclosure will be further described in detail below in conjunction with specific examples. The following examples are merely illustrative of the present disclosure and are not to be construed as limiting the scope of the present disclosure. The technology that is implemented based on the above-described contents of the present disclosure is encompassed within the scope of the present disclosure.

[0078] Instruments and Apparatuses

[0079] The specific surface areas in the following examples were determined by a nitrogen physical adsorber model Belsorp Mini II of MicrotracBEL Corp. The compressive strength was determined by the pressure tester of Shanghai Yihuan Instrument Technology Co., Ltd.

Example 1

[0080] 1.1 Preparation of Spherical Polymer Matrix

[0081] 18 liters of water were added into a 50-liter polymerization kettle, heated to 45 C., to which 10 g magnesium carbonate, 20 g of gelatin and 0.15 g of methylene blue were added respectively under stirring. After the system was stirred evenly, an oil phase consisting of 3 kg methylstyrene, 1 kg dipentene and 20 g benzoyl peroxide were added into the system, and then 1.0 kg of paraffin was added, and the polymerization kettle was closed. Clean compressed air was introduced into the polymerization kettle, so that the gas phase pressure in the kettle was kept at 0.02 MPa. Stirring was turned on, the liquid beads in the kettle were adjusted to an appropriate particle size, the system was heated to 80 C. and hold for 12 hours, followed by being heated to 100 C. and hold for 20 hours. The reaction mixture was filtered, washed, dried and sieved to give 2.35 kg white spherical polymer.

[0082] 1.2 Sulfonation and Carbonization

[0083] The spherical polymer obtained in step 1.1 was mixed with concentrated sulfuric acid at a mass ratio of 1:1, then the mixture was added to an acid resistant rotary tubular furnace. Under a nitrogen atmosphere, the mixture was subjected to the following heating process at the heating rate of 5 C./min:

[0084] heating to 100 C., holding for 120 minutes;

[0085] heating to 150 C., holding for 240 minutes;

[0086] and subjected to the following heating process at the heating rate of 4 C./min: heating to 300 C., holding for 120 minutes;

[0087] heating to 500 C., holding for 240 minutes;

[0088] then heating to 650 C., holding for 100 minutes.

[0089] After cooling, the carbonized product was obtained.

[0090] 1.3 Activation

[0091] In a rotary tubular furnace, under the mixed atmosphere of water vapor and nitrogen with a flow rate ratio of 1:4.5 (L/min), the carbonized product obtained in step 1.2 was heated to 800 C. at a rate of 3 C./min, hold for 360 minutes, then under the mixed atmosphere of CO.sub.2 and nitrogen with a flow rate ratio of 1:4 (L/min), it was further heated to 950 C. at a rate of 3 C./min, hold for 120 minutes. After cooling, spherical activated carbon GSC1 was obtained, with a yield of 37% based on the polymer, a median particle size of 0.75 mm, a median pore size of 3.50 nm, a specific surface area of 958 m.sup.2/g, a compressive strength of 79.90 N, a bulk density of 470 g/L, and a cracking rate of 4.72%.

Example 2

[0092] 2.1 Preparation of Spherical Polymer Matrix

[0093] 20 liters of water were added into a 50-liter polymerization kettle, heated to 40 C., to which 10 g of calcium carbonate, 20 g polyvinyl alcohol and 0.15 g calcium petroleum sulfonate were added respectively under stirring. After the system was stirred evenly, an oil phase consisting of 3 kg styrene, 1 kg isoprene and 20 g azodiisobutyronitrile were added into the system, and then 1.6 kg glycerol was added, and the polymerization kettle was closed. clean compressed air was introduced into the polymerization kettle, so that the gas phase pressure in the kettle was kept at 0.04 MPa. Stirring was turned on, the liquid beads in the kettle were adjusted to an appropriate particle size, the system was heated to 80 C. and hold for 12 hours, followed by being heated to 100 C. and hold for 20 hours. The reaction mixture was filtered, washed, dried and sieved to give 2.76 kg white spherical polymer.

[0094] 2.2 Sulfonation and Carbonization

[0095] The spherical polymer obtained in step 2.1 was mixed with SO.sub.3 at a mass ratio of 1:1.5, then the mixture was added to an acid resistant rotary tubular furnace. Under a helium atmosphere, the mixture was subjected to the following heating process at the heating rate of 4 C./min:

[0096] heating to 80 C., holding for 60 minutes;

[0097] heating to 150 C., holding for 300 minutes;

[0098] and subjected to the following heating process at the heating rate of 3 C./min under a mixed atmosphere containing 5% by volume of oxygen:

[0099] heating to 200 C., holding for 90 minutes;

[0100] heating to 500 C., holding for 320 minutes;

[0101] then heating to 600 C., holding for 120 minutes.

[0102] After cooling, the carbonized product was obtained.

[0103] 2.3 Activation

[0104] In a rotary tubular furnace, under the mixed atmosphere of water vapor and nitrogen with a flow rate ratio of 1:4, the carbonized product obtained in step 2.2 was heated to 950 C. at a rate of 3 C./min, hold for 360 minutes, then under the mixed atmosphere of CO.sub.2 and nitrogen with a flow rate ratio of 1:3 (L/min), it was further heated to 950 C. at a rate of 4 C./min, hold for 120 minutes. After cooling, spherical activated carbon GSC2 was obtained, with a yield of 39% based on the polymer, a median particle size of 1.15 mm, a median pore size of 1.90 nm, a specific surface area of 956 m.sup.2/g, a compressive strength of 52.76 N, a bulk density of 460 g/L, a cracking rate of 4.62%.

Example 3

[0105] 3.1 Preparation of Spherical Polymer Matrix

[0106] 20 liters of water were added into a 50-liter polymerization kettle, heated to 40 C., to which 12 g magnesium carbonate, 25 g sodium carboxymethylcellulose and 0.18 g calcium dodecylbenzene sulfonate were added respectively under stirring. After the system was stirred evenly, an oil phase consisting of 3.6 kg divinylbenzene, 1.2 kg diethylene glycol divinyl ether and 25 g sodium persulfate were added into the system, and then 2.2 kg sodium carbonate was added, the polymerization kettle was closed. Clean compressed air was introduced into the polymerization kettle, so that the gas phase pressure in the kettle was kept at 0.05 MPa. Stirring was turned on, the liquid beads in the kettle were adjusted to an appropriate particle size, the system was heated to 90 C. and hold for 9 hours, followed by being heated to 120 C. and hold for 20 hours. The reaction mixture was filtered, washed, dried and sieved to give 3.12 kg white spherical polymer.

[0107] 3.2 Sulfonation and Carbonization

[0108] The spherical polymer obtained in step 3.1 was added into the polymerization kettle, to which 10 kg fuming sulfuric acid with mass concentration of 105% were added into the polymerization kettle. The system was heated to 110 C. and hold for 16 hours, followed by adding water dropwise slowly after the temperature decreased. liquid was suctioned out when the kettle was full, and the water was sequentially added dropwise, so that the sulfuric acid concentration in the kettle was less than 5%. The product was dried to give 4.28 kg spherical polymer. Under a nitrogen atmosphere, the polymer microsphere was subjected to the following heating process at a heating rate of 3 C./min:

[0109] heating to 120 C., holding for 110 minutes;

[0110] heating to 180 C., holding for 250 minutes;

[0111] and subjected to the following heating process at the heating rate of 3 C./min under a mixed atmosphere containing 1% by volume of oxygen:

[0112] heating to 250 C., holding for 360 minutes;

[0113] heating to 450 C., holding for 240 minutes;

[0114] then heating to 700 C., holding for 90 minutes.

[0115] After cooling, carbonization products were obtained.

[0116] 3.3 Activation

[0117] In a rotary tubular furnace, under the mixed atmosphere of water vapor and nitrogen with a flow rate ratio of 1:7 (L/min), the carbonized product obtained in step 3.2 was heated to 800 C. at a rate of 3 C./min, hold for 420 minutes, then under the mixed atmosphere of CO.sub.2 and nitrogen with a flow rate ratio of 1:7 (L/min), it was further heated to 950 C. at a rate of 4 C./min, hold for 200 minutes. After cooling, spherical activated carbon GSC3 was obtained, with a yield of 42% based on the polymer, a median particle size of 0.90 mm, a median pore size of 2.95 nm, a specific surface area of 1011 m.sup.2/g, a compressive strength of 78.24 N, a bulk density of 514 g/L, and a cracking rate of 3.32%.

Example 4

[0118] 4.1 Preparation of Spherical Polymer Matrix

[0119] 18 liters of water were added into a 50-liter polymerization kettle, heated to 45 C., to which 10 g magnesium carbonate, 20 g gelatin and 0.15 g methylene blue were added respectively under stirring. After the system was stirred evenly, an oil phase consisting of 3 kg methylstyrene, 1 kg dipentene and 20 g benzoyl peroxide were added into the system, and then 1.3 kg magnesium sulphate was added, and the polymerization kettle was closed. Clean compressed air was introduced into the polymerization kettle, so that the gas phase pressure in the kettle was kept at 0.02 MPa. Stirring was turned on, the liquid beads in the kettle were adjusted to an appropriate particle size, the system was heated to 80 C. and hold for 12 hours, followed by being heated to 100 C. and hold for 20 hours. The reaction mixture was filtered, washed, dried and sieved to give 2.51 kg white spherical polymer.

[0120] 4.2 Sulfonation and Carbonization

[0121] The spherical polymer obtained in step 4.1 was mixed with concentrated sulfuric acid at a mass ratio of 1:1.3, then the mixture was added to an acid resistant rotary tubular furnace. Under a nitrogen atmosphere, the mixture was subjected to the following heating process at the heating rate of 2 C./min:

[0122] heating to 60 C., holding for 60 minutes;

[0123] heating to 130 C., holding for 100 minutes;

[0124] heating to 160 C., holding for 150 minutes;

[0125] and subjected to the following heating process at the heating rate of 3 C./min under a mixed atmosphere containing 3% by volume of oxygen:

[0126] heating to 400 C., holding for 240 minutes;

[0127] heating to 550 C., holding for 240 minutes;

[0128] then heating to 700 C., holding for 100 minutes.

[0129] After cooling, the carbonized product was obtained.

[0130] 4.3 Activation

[0131] In a rotary tubular furnace, under the mixed atmosphere of water vapor and nitrogen with a flow rate ratio of 1:6.5 (L/min), the carbonized product obtained in step 4.2 was heated to 750 C. at a rate of 3 C./min, hold for 300 minutes, then under the mixed atmosphere of CO.sub.2 and nitrogen with a flow rate ratio of 1:5.5 (L/min), it was further heated to 980 C. at a rate of 2 C./min, hold for 300 minutes. After cooling, spherical activated carbon GSC4 was obtained, with a yield of 41% base on polymer, a median particle size of 0.55 mm, a median pore size of 2.19 nm, a specific surface area of 704 m.sup.2/g, a compressive strength of 124.72 N, a bulk density of 675 g/L, and a cracking rate of 4.92%.

Example 5 Determination of Iodine Adsorption Value

[0132] The iodine adsorption values of the spherical activated carbons GSC1 to GSC4 prepared in the above Example 1-4 were determined according to GB/T 12496.8-2015, named TEST METHOD OF WOODEN ACTIVATED CARBON: DETERMINATION OF IODINE ADSORPTION VALUE. The results were shown in Table 1.

TABLE-US-00001 TABLE 1 iodine adsorption values of the spherical activated carbons prepared in Example 1-4 Example Iodine adsorption value (mg/g) Example 1 800 Example 2 780 Example 3 950 Example 4 600

[0133] The above content explained the embodiment of the disclosure. However, the present disclosure is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the disclosure.