阅读说明：本技术 一种超级活性炭的制备方法 (Preparation method of super activated carbon ) 是由 应盛荣 姜战 应悦 于 2020-12-29 设计创作，主要内容包括：本发明提出了一种超级活性炭的制备方法,包括,粉碎原料活性炭；将粉碎后的活性炭加入含有盐酸和氢氟酸的混合酸液中,加热至40～90℃,搅拌反应5～120min；上述反应完毕后,分离酸液与活性炭,并清洗活性炭至PH≥5；将清洗后的活性炭在90～140℃烘干；烘干后的活性炭与KOH固体以1：0.4～2.0的重量比混合,然后进行750～850℃的高温活化,冷却后即得超级活性炭成品。本发明选用盐酸与氢氟酸的混合酸液,只需要一次酸洗即可,缩短操作步骤,节能能耗；同时,一次酸洗也能减少废酸的量,利于后续酸回收。制得的超级活性炭比表面积大,吸附能力强。(The invention provides a preparation method of super activated carbon, which comprises the steps of crushing raw material activated carbon; adding the crushed activated carbon into a mixed acid solution containing hydrochloric acid and hydrofluoric acid, heating to 40-90 ℃, and stirring for reaction for 5-120 min; after the reaction is finished, separating acid liquor from the activated carbon, and cleaning the activated carbon until the pH value is more than or equal to 5; drying the cleaned activated carbon at 90-140 ℃; mixing the dried activated carbon and KOH solid in a ratio of 1: 0.4-2.0, then carrying out high-temperature activation at 750-850 ℃, and cooling to obtain the super activated carbon finished product. The method selects the mixed acid solution of hydrochloric acid and hydrofluoric acid, only needs one-time acid cleaning, shortens the operation steps, and saves energy and energy consumption; meanwhile, the amount of waste acid can be reduced by one-time acid washing, and the subsequent acid recovery is facilitated. The prepared super activated carbon has large specific surface area and strong adsorption capacity.)

1. A preparation method of super activated carbon is characterized by comprising the following steps,

crushing raw material active carbon;

adding the crushed activated carbon into a mixed acid solution containing hydrochloric acid and hydrofluoric acid, heating to 40-90 ℃, and stirring for reaction for 5-120 min; wherein the concentration of hydrochloric acid in the mixed acid liquid is 5-25 wt%, and the concentration of hydrofluoric acid is 5-25 wt%;

after the reaction is finished, separating acid liquor from the activated carbon, and cleaning the activated carbon until the pH value is more than or equal to 5; drying the cleaned activated carbon at 90-140 ℃;

mixing the dried activated carbon and KOH solid in a ratio of 1: mixing the components in a weight ratio of 0.4-2.0, then activating at a high temperature of 750-850 ℃, and cooling to obtain a super activated carbon finished product;

the separated acid solution is waste acid; the waste acid is treated by a waste acid recovery circulating system and then reused;

the recovery process of the waste acid comprises the following steps:

adding concentrated sulfuric acid into the waste acid to generate HCl gas and SiF₄Gas and HF gas; condensing to obtain hydrogen fluoride liquid, and converting concentrated sulfuric acid into dilute sulfuric acid;

compressing and cooling HClGas and SiF₄Gas to obtain hydrogen chloride liquid; absorbing with water to obtain hydrochloric acid solution;

SiF₄absorbing the gas with water to obtain silicon dioxide and fluosilicic acid solution; after the silicon dioxide is separated, the fluosilicic acid is returned to be mixed with the waste acid;

preparing hydrogen fluoride liquid and hydrochloric acid solution with water, and then re-using the hydrogen fluoride liquid and the hydrochloric acid solution as mixed acid liquid;

the dilute sulfuric acid is concentrated to become concentrated sulfuric acid again for recycling.

2. The method for preparing super activated carbon according to claim 1, wherein the specific surface area of the raw material activated carbon is less than or equal to 1000M²/g。

3. The method of claim 1 or 2, wherein the activated carbon is pulverized into 100-500 mesh.

4. The method for preparing super activated carbon according to claim 3, wherein the pH of the washed activated carbon is 5-7.

5. The method for preparing super activated carbon according to claim 1, wherein the drying time is 4-8 hours.

6. The method for preparing the super activated carbon according to claim 1, wherein the specific surface area of the super activated carbon is more than or equal to 2500M²/g。

7. The method for preparing super activated carbon according to claim 6, wherein the condensation temperature is 10 to-15 ℃.

8. The method for preparing super activated carbon according to claim 6, wherein the pressure of the compressed gas is 2.0-3.0 MPa, and the gas cooling temperature is 10-minus 10 ℃.

Technical Field

The invention relates to the field of super activated carbon, in particular to a preparation method of super activated carbon.

Background

Activated Carbon (AC) is a broad-spectrum adsorbent, the adsorption capacity of which depends mainly on the specific surface area and pore size distribution of activated carbon. Conventional activated carbon due to its small specific surface area (<1500m²The pore size distribution is wide (the pore size distribution is in the range of 1 nm-100 nm), the selective adsorption is poor, and the special requirements in the fields of increasingly developed medicine, environmental protection, military, electronics and the like can not be met, so that a plurality of novel activated carbon materials are researched and developed at home and abroad in recent years. Wherein the super activated carbon has high specific surface area (>2200m²/g), concentrated micropore distribution, excellent adsorption performance and the like, and is widely applied to the fields of medicine, catalysis, gas separation and storage, super capacitors, energy storage batteries and the like. According to the indexes in national standard GBT 37386-2019 of activated carbon for super capacitor, the best I-grade activated carbon has a specific surface area of more than or equal to 2000m²(ii)/g; the specific surface area of the activated carbon for RAC-I-2200 resin class-I super capacitor is 2200m²/g。

CN104291333A, published 2015, 1 month and 21 days, entitled preparation method of high specific surface area stone coal based mesoporous activated carbon, wherein concentrated sulfuric acid and hydrofluoric acid are used as mixed acid liquid, and the use of the mixed acid liquid can cause insoluble salt to be generated, so that pores of the activated carbon are blocked, and the adsorption capacity of the activated carbon is influenced. And the method also has the problem that the waste acid is difficult to recover.

CN109133055A, published 2019, 1 month and 4 days, invents a preparation method and application of high-purity medium-temperature coal pitch-based super activated carbon, wherein hydrochloric acid and hydrofluoric acid are used for treating samples in a grading manner, so that not only is the process flow increased, but also the generated waste acid is increased, and the problem of treating more waste acid is not solved.

CN101209840A, published 2008, 7/2, entitled method for preparing high specific surface area coal-based activated carbon, in which a sample is activated first and then soaked in hydrochloric acid two to three times, which has the disadvantage that multiple acid treatments generate waste acid and the problem of waste acid treatment is not mentioned.

Ash in the activated carbon severely restricts the adsorption capacity of the activated carbon; the ash content of the super activated carbon is lower than 0.3%, many enterprises want to remove ash by using inorganic acid liquor to prepare the super activated carbon, but waste acid generated in the production process is difficult to treat, so that the serious problem of environmental pollution is caused, and if the waste acid is subjected to harmless treatment, the cost is high, so that the production cost of the super activated carbon is high. There are also enterprises wanting to remove ash by strong alkali to produce super activated carbon; strong alkali is used, high-temperature reaction is needed, and energy consumption is large; and also creates disposal problems for alkaline waste liquids and water.

Disclosure of Invention

The invention provides a preparation method of super activated carbon, which solves the problems of high energy consumption and high ash content in the super activated carbon in the process of preparing the super activated carbon in the prior art.

The invention also solves the problem of serious pollution in the prior preparation of the super activated carbon, solves the recycling of waste acid and greatly reduces the preparation cost.

The technical scheme of the invention is realized as follows:

a preparation method of super activated carbon comprises the following steps,

crushing raw material active carbon;

adding the crushed activated carbon into a mixed acid solution containing hydrochloric acid and hydrofluoric acid, heating to 40-90 ℃, and stirring for reaction for 5-120 min; wherein the concentration of hydrochloric acid in the mixed acid liquid is 5-25 wt%, and the concentration of hydrofluoric acid is 5-25 wt%;

after the reaction is finished, separating acid liquor from the activated carbon, and cleaning the activated carbon until the pH value is more than or equal to 5; drying the cleaned activated carbon at 90-140 ℃;

mixing the dried activated carbon and KOH solid in a ratio of 1: mixing the components in a weight ratio of 0.4-2.0, then activating at a high temperature of 750-850 ℃, and cooling to obtain a super activated carbon finished product;

the separated acid solution is waste acid; the waste acid is reused after being treated by a waste acid recycling circulating system.

In some embodiments, the feedstock activated carbon has a specific surface area of 1000M or less²/g。

In some embodiments, the activated carbon powder is ground to 100-500 mesh.

In some embodiments, the pH of the activated carbon after cleaning is 5-7.

In some embodiments, the drying time is 4 to 8 hours.

In some embodiments, the specific surface area of the super activated carbon is more than or equal to 2500M²/g。

In some embodiments, the spent acid recovery process is:

adding concentrated sulfuric acid into the waste acid to generate HCl gas and SiF₄Gas and HF gas; condensing to obtain hydrogen fluoride liquid, and converting concentrated sulfuric acid into dilute sulfuric acid;

compressing and cooling HCl gas and SiF₄Gas to obtain hydrogen chloride liquid; absorbing with water to obtain hydrochloric acid solution;

SiF₄absorbing the gas with water to obtain silicon dioxide and fluosilicic acid solution; after the silicon dioxide is separated, the fluosilicic acid is returned to be mixed with the waste acid;

preparing hydrogen fluoride liquid and hydrochloric acid solution with water, and then re-using the hydrogen fluoride liquid and the hydrochloric acid solution as mixed acid liquid;

the dilute sulfuric acid is concentrated to become concentrated sulfuric acid again for recycling.

In some embodiments, the condensation temperature is between 10 ℃ and-15 ℃.

In some embodiments, the compressed gas has a pressure of 2.0 to 3.0MPa and a gas cooling temperature of 10 to-10 ℃.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method selects the mixed acid solution of hydrochloric acid and hydrofluoric acid, only needs one-time acid cleaning, shortens the operation steps, and saves energy and energy consumption; meanwhile, the amount of waste acid can be reduced by one-time acid washing, and the subsequent acid recovery is facilitated.

(2) The super activated carbon prepared by the method has large specific surface area (the specific surface area is more than or equal to 2700M)²(g) and has strong adsorption capacity.

(3) The concentration of the hydrochloric acid and the concentration of the hydrofluoric acid are low, and the production safety is improved.

(4) The method firstly removes ash and then activates; the silicon dioxide and alkali metal oxide in the ash content do not consume KOH in the activation process; the consumption of the potassium hydroxide can be greatly reduced, so that the production cost of the product is further reduced.

(5) The consumption of cleaning water in the process is only about 0.8 time of the weight of the activated carbon material, and water resources are saved.

(6) The waste acid is recycled, so that the pollution is reduced, the materials are recycled, the process can be carried out circularly, the production efficiency is improved, and the energy is saved and the consumption is reduced; the production cost is reduced, and the market competitiveness of the product is improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The reagents used in the examples of the present invention are all commercially available.

Example 1

A preparation method of super activated carbon comprises the following steps,

(1) taking 1200g of common active carbon (the specific surface area is less than or equal to 1000M)²(g) and pulverizing it in a pulverizer; the mesh number after crushing can be 100 meshes to 500 meshes.

(2) Adding 1800ml of mixed acid liquid into the deashing reaction kettle; the concentration of hydrochloric acid in the mixed acid solution is 5 wt%, and the concentration of hydrofluoric acid is 25 wt%. Hydrofluoric acid can react with silicon dioxide in ash to generate fluosilicic acid, so that the silicon dioxide is removed, and other metal oxides are stripped from the main material, thereby reducing the content of the metal oxides on the main material; the hydrochloric acid can react with metal oxides (such as alumina, calcium oxide, etc.) in the ash to generate soluble substances such as aluminum chloride, calcium chloride, etc., so that the soluble substances are removed from the main material.

Pouring the activated carbon crushed in the step (1) into a deashing reaction kettle, and stirring for reaction for 1 hour at the reaction temperature of 50 ℃.

(3) After the reaction in the step (2) is completed, separating the activated carbon by solid-liquid separation, and washing the activated carbon by pure water at room temperature until the pH value is more than or equal to 5. The waste acid is reused after being treated by a waste acid recycling circulating system.

(4) The washed activated carbon was placed in an oven for 4 hours at a temperature of 130 ℃.

Mixing the dried activated carbon and KOH solid in a ratio of 1: 0.4 weight ratio, then carrying out high-temperature activation at 850 ℃, and cooling to obtain 1068g of a finished product of the super activated carbon.

Detecting the super activated carbon: the ash content is 0.26 percent,effective specific surface area 2870M²/g。

The recovery process of waste acid is as follows:

adding concentrated sulfuric acid into the waste acid separated in the step (3) to generate HCl gas and SiF₄Gas and HF gas; hydrogen fluoride liquid is obtained after condensation at 10 ℃, and concentrated sulfuric acid becomes dilute sulfuric acid.

3.0MPa compression and cooling of HCl gas and SiF at-10 ℃₄Gas to obtain hydrogen chloride liquid; absorbed with water as a hydrochloric acid solution.

SiF₄Absorbing the gas with water to obtain silicon dioxide and fluosilicic acid solution; after the silicon dioxide is separated, the fluosilicic acid is returned to be mixed with the waste acid.

Preparing hydrogen fluoride liquid and hydrochloric acid solution with water, and then re-using the hydrogen fluoride liquid and the hydrochloric acid solution as mixed acid liquid;

the dilute sulfuric acid is concentrated to become concentrated sulfuric acid again for recycling.

Example 2

A preparation method of super activated carbon comprises the following steps,

(1) taking 1200g of common active carbon (the specific surface area is less than or equal to 1000M)²(g) and pulverizing it in a pulverizer; the mesh number after crushing can be 100 meshes to 500 meshes.

(2) 1800ml of mixed acid liquid is added into the deashing reaction kettle, the concentration of hydrochloric acid in the mixed acid liquid is 10 wt%, and the concentration of hydrofluoric acid is 20 wt%.

Pouring the activated carbon crushed in the step (1) into a deashing reaction kettle, and stirring for reaction for 2 hours at the reaction temperature of 60 ℃.

(3) After the reaction in the step (2) is completed, separating the activated carbon by solid-liquid separation, and washing the activated carbon by pure water at room temperature until the pH value is more than or equal to 5. The waste acid is reused after being treated by a waste acid recycling circulating system.

(4) The washed activated carbon was placed in an oven for 4 hours at a temperature of 130 ℃. To obtain 1054g of super activated carbon finished product.

Mixing the dried activated carbon and KOH solid in a ratio of 1: 1 weight ratio, then carrying out high-temperature activation at 750 ℃, and cooling to obtain 1054g of a super activated carbon finished product.

Detecting the super activated carbon: the ash content is 0.23 percent,effective specific surface area 2986M²/g。

The recovery process of waste acid is as follows:

adding concentrated sulfuric acid into the waste acid separated in the step (3) to generate HCl gas and SiF₄Gas and HF gas; hydrogen fluoride liquid is obtained after condensation at the temperature of minus 15 ℃, and concentrated sulfuric acid becomes dilute sulfuric acid.

Compressing at 2.0MPa and cooling HCl gas and SiF at-10 deg.C₄Gas to obtain hydrogen chloride liquid; absorbed with water as a hydrochloric acid solution.

SiF₄Absorbing the gas with water to obtain silicon dioxide and fluosilicic acid solution; after the silicon dioxide is separated, the fluosilicic acid is returned to be mixed with the waste acid.

Preparing hydrogen fluoride liquid and hydrochloric acid solution with water, and then re-using the hydrogen fluoride liquid and the hydrochloric acid solution as mixed acid liquid;

the dilute sulfuric acid is concentrated to become concentrated sulfuric acid again for recycling.

Example 3

A preparation method of super activated carbon comprises the following steps,

(1) taking 1200g of common active carbon (the specific surface area is less than or equal to 1000M)²(g) and pulverizing it in a pulverizer; the mesh number after crushing can be 100 meshes to 500 meshes.

(2) Adding mixed acid liquid into the deashing reaction kettle, wherein the concentration of hydrochloric acid in the mixed acid liquid is 25 wt%, and the concentration of hydrofluoric acid in the mixed acid liquid is 5 wt%.

Pouring the activated carbon crushed in the step (1) into a deashing reaction kettle, and stirring for reaction for 2 hours at the reaction temperature of 90 ℃.

(3) After the reaction in the step (2) is completed, separating the activated carbon by solid-liquid separation, and washing the activated carbon by pure water at room temperature until the pH value is more than or equal to 5. The waste acid is reused after being treated by a waste acid recycling circulating system.

(4) The washed activated carbon was placed in an oven for 4 hours at a temperature of 130 ℃.

Mixing the dried activated carbon and KOH solid in a ratio of 1: 2, then activating at high temperature of 750 ℃, and cooling to obtain 1080g of finished product of the super activated carbon.

Detecting the super activated carbon: ash content of 0.31%, effective specific surface area of 2753M²/g。

The recovery process of waste acid is as follows:

adding concentrated sulfuric acid into the waste acid separated in the step (3) to generate HCl gas and SiF₄Gas and HF gas; condensing at-10 deg.c to obtain hydrogen fluoride liquid and converting concentrated sulfuric acid into dilute sulfuric acid.

Compressing under 2.0MPa and cooling HCl gas and SiF at 10 deg.C₄Gas to obtain hydrogen chloride liquid; absorbed with water as a hydrochloric acid solution.

SiF₄Absorbing the gas with water to obtain silicon dioxide and fluosilicic acid solution; after the silicon dioxide is separated, the fluosilicic acid is returned to be mixed with the waste acid.

Preparing hydrogen fluoride liquid and hydrochloric acid solution with water, and then re-using the hydrogen fluoride liquid and the hydrochloric acid solution as mixed acid liquid;

the dilute sulfuric acid is concentrated to become concentrated sulfuric acid again for recycling.