阅读说明：本技术 一种高吸附性能活性炭制备方法及应用 (Preparation method and application of high-adsorption-performance activated carbon ) 是由 卢辛成 徐茹婷 蒋剑春 孙康 王傲 陈超 张燕萍 于 2020-12-24 设计创作，主要内容包括：本发明公开了一种高吸附性能活性炭的制备方法及应用。将生物质原料,木屑、枝丫、秸秆等,破碎、酸洗、水洗后烘干；将硫酸加入到一定质量分数的硝酸锌溶液中,配制成混合活化剂；生物质原料与混合活化剂按一定比例均匀混合,室温下浸渍3h后置于管式炉中,在氮气保护下升温至600～800℃活化1～3h,冷却至室温后,依次经过酸洗、水洗至溶液pH为中性,干燥后即得活性炭。活性炭对Hg～(2+)吸附容量可达298.75mg/g。本发明通过使用混合活化剂,极大降低了活性炭制备过程中活化剂消耗,较传统磷酸法活化工艺降低了6～10倍；制备出具有高吸附性能的活性炭,适用于重金属吸附及水污染治理。(The invention discloses a preparation method and application of high-adsorption-performance activated carbon. Crushing, pickling and washing biomass raw materials, wood chips, twigs, straws and the like, and then drying; adding sulfuric acid into a zinc nitrate solution with a certain mass fraction to prepare a mixed activator; uniformly mixing a biomass raw material and a mixed activating agent according to a certain proportion, soaking for 3 hours at room temperature, then placing in a tubular furnace, heating to 600-800 ℃ under the protection of nitrogen, activating for 1-3 hours, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. Activated carbon to Hg 2+ The adsorption capacity can reach 298.75 mg/g. According to the invention, the consumption of the activating agent in the preparation process of the activated carbon is greatly reduced by using the mixed activating agent, and is reduced by 6-10 times compared with the traditional phosphoric acid method activation process; preparing the active carbon with high adsorption performanceIt is used for heavy metal adsorption and water pollution treatment.)

1. The preparation method of the activated carbon with high adsorption performance is characterized by comprising the following steps:

1) crushing, acid washing and water washing biomass raw materials, and drying;

2) adding sulfuric acid into a zinc nitrate solution to prepare a mixed activating agent;

3) uniformly mixing the clean and dry biomass raw material with a mixed activating agent, and soaking at room temperature;

4) placing the mixture obtained in the step 3) in a tubular furnace, heating and activating under the protection of nitrogen, and cooling to obtain an activated material;

5) and (4) sequentially carrying out acid washing and water washing on the activated material until the pH value of the solution is neutral, and drying to obtain the activated carbon.

2. The preparation method of the activated carbon with high adsorption performance according to claim 1, wherein the mass fraction of the zinc nitrate in the step 2) is 5-15%.

3. The method for preparing activated carbon with high adsorption performance according to claim 1, wherein the temperature rise rate in the step 4) is 10 ℃/min.

4. The preparation method of the activated carbon with high adsorption performance according to claim 1, wherein the mass ratio of the zinc nitrate to the sulfuric acid in the mixed activator in the step 2) is 1 (0.05-0.1).

5. The preparation method of the activated carbon with high adsorption performance according to claim 1, wherein the mass ratio of the wood chips to the zinc nitrate in the step 3) is 1 (0.1-0.5).

6. The method for preparing activated carbon with high adsorption performance according to claim 1, wherein the activation temperature in the step 4) is 600-800 ℃.

7. The preparation method of the activated carbon with high adsorption performance according to claim 1, wherein the activation time in the step 4) is 1-3 h.

8. The method for preparing the activated carbon with high adsorption performance according to claim 1, wherein the biomass raw material is any one of wood chips, twigs and straws.

9. The use of the activated carbon obtained by the method for preparing activated carbon with high adsorption performance according to any one of claims 1 to 8 in heavy metal adsorption and water pollution treatment.

Technical Field

The invention belongs to the technical field of preparation of bio-based activated carbon materials, and particularly relates to a preparation method and application of activated carbon with high adsorption performance.

Background

The active carbon has huge specific surface area, abundant pore structures and good adsorption performance, is an environment-friendly adsorption and purification material, has wide application in various fields such as environmental protection, pollution control, energy storage, national defense and the like, plays an important role, and is an indispensable product of national economy.

China is the first country for production and export of activated carbon. The chemical activation method is one of the main technologies for preparing and producing the activated carbon in China, and has the characteristics of simple production process, large production scale, stable product quality and the like. The chemical activation method is a method for preparing activated carbon by uniformly mixing (or impregnating) various carbon-containing raw materials with a chemical activating agent, and subjecting the mixture to processes of carbonization, activation, chemical recovery, rinsing, drying and the like at a proper temperature. At present, phosphoric acid, potassium hydroxide, zinc chloride and the like are mainly used as common activating agents.

The chemical activation method uses chemical reagents in the production process, can generate waste gas and waste water, not only pollutes the environment and harms the health, but also increases the operation cost of enterprises. With the technical upgrade and the environmental protection requirement in China, the development trend of low-consumption preparation technology and high-performance material development is. Therefore, the method has important significance for reducing the consumption of the activating reagent and preparing the high-performance activated carbon.

Disclosure of Invention

The invention aims to solve the problems in the background art, and provides a preparation method and application of activated carbon with high adsorption performance, the method is simple, the consumption of an activating agent is low, and the prepared activated carbon has excellent adsorption performance.

The technical scheme of the invention is as follows: a preparation method of activated carbon with high adsorption performance comprises the following steps:

1) crushing, acid washing and water washing biomass raw materials, and drying;

2) adding sulfuric acid into a zinc nitrate solution to prepare a mixed activating agent;

3) uniformly mixing the clean and dry biomass raw material with a mixed activating agent, and soaking at room temperature;

4) placing the mixture obtained in the step 3) in a tubular furnace, heating and activating under the protection of nitrogen, and cooling to obtain an activated material;

5) and (4) sequentially carrying out acid washing and water washing on the activated material until the pH value of the solution is neutral, and drying to obtain the activated carbon.

And in the step 2), the mass fraction of the zinc nitrate is 5-15%.

And 4) the heating rate during heating is 10 ℃/min.

The mass ratio of the zinc nitrate to the sulfuric acid in the mixed activating agent in the step 2) is 1 (0.05-0.1).

And 3) the mass ratio of the wood dust to the zinc nitrate is 1 (0.1-0.5).

And 4) the activation temperature is 600-800 ℃.

And 4) activating for 1-3 h.

The biomass raw material is any one of wood chips, twigs and straws.

An application of the activated carbon prepared by the preparation method of the activated carbon with high adsorption performance in heavy metal adsorption and water pollution treatment.

Has the advantages that:

the preparation method of the high-adsorption-property activated carbon is simple, the raw material adaptability is wide, the consumption of an activating reagent is greatly reduced, the consumption is reduced by 6-10 times compared with that of the traditional phosphoric acid method activating process, and the emission of pollutants in the preparation process is less. The prepared active carbon has excellent adsorption performance and is suitable for heavy metal adsorption and water pollution treatment. Activated carbon to Hg²⁺The adsorption capacity can reach 298.75 mg/g.

Detailed Description

A preparation method of activated carbon with high adsorption performance comprises the following steps:

1) crushing, pickling and washing biomass raw materials (wood chips, twigs, straws and the like), and drying at 110 ℃;

2) adding sulfuric acid and zinc nitrate into water according to a certain mass ratio to prepare mixed activators with different mass fractions;

3) uniformly mixing a clean and dry biomass raw material with mixed activators with different mass fractions, and soaking for 3 hours at room temperature;

4) placing the mixture obtained in the step 3) in a tubular furnace, heating to 600-800 ℃ under the protection of nitrogen, activating for 1-3 h, and cooling to obtain an activated material;

5) and (4) sequentially carrying out acid washing and water washing on the activated material until the pH value of the solution is neutral, and drying to obtain the activated carbon.

Preferably, the method comprises the following steps:

and in the step 2), the mass fraction of the zinc nitrate is 5-15%.

And 2) the mixed activating agent is a mixture of zinc nitrate and sulfuric acid.

The mass ratio of the zinc nitrate to the sulfuric acid in the mixed activating agent in the step 2) is 1 (0.05-0.1).

And 3) the mass ratio of the wood dust to the zinc nitrate is 1 (0.1-0.5).

And 4) the activation temperature is 600-800 ℃.

And 4) activating for 1-3 h.

Example 1:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C; adding 1.53g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 15% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried sawdust, stirring uniformly, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 700 ℃ under the protection of nitrogen for activation for 2h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 242.5.50 mg/g.

Example 2:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C; adding 0.82g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 10% to prepare a mixed activator; adding 10g of dried sawdust into 30g of the mixed activating agent, stirring uniformly, soaking for 3h at room temperature, and placing in a tube furnaceHeating to 700 ℃ under the protection of nitrogen, activating for 3h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 206.75 mg/g.

Example 3:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C; adding 1.53g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 15% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried sawdust, stirring uniformly, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 800 ℃ under the protection of nitrogen for activation for 2h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 298.75 mg/g.

Example 4:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C; adding 1.53g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 15% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried sawdust, stirring uniformly, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 800 ℃ under the protection of nitrogen for activation for 2.5h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 225.50 mg/g.

Example 5:

crushing and screening the branches into particles of 1-2 mm, pickling and washing at normal temperature, and drying at 110 ℃; adding 0.82g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 10% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried sawdust, stirring uniformly, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 600 ℃ under the protection of nitrogen for activation for 2h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 153.75 mg/g.

Example 6:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C(ii) a Adding 0.51g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 5% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried sawdust, stirring uniformly, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 800 ℃ under the protection of nitrogen for activation for 2h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 182.50 mg/g.

Example 7:

crushing and screening cotton stalks into particles of 1-2 mm, pickling and washing at normal temperature, and drying at 110 ℃; adding 0.61g of concentrated sulfuric acid (98%) into 100g of zinc nitrate solution with the mass fraction of 10% to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried cotton stalks, stirring uniformly, soaking for 3h at room temperature, then placing in a tube furnace, heating to 800 ℃ under the protection of nitrogen for activation for 2h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 196.50 mg/g.

Example 8:

crushing and screening cotton stalks into particles of 1-2 mm, pickling and washing at normal temperature, and drying at 110 ℃; adding 1.22g of concentrated sulfuric acid (98%) into 100g of 15% zinc nitrate solution by mass percent to prepare a mixed activator; adding 30g of the mixed activating agent into 10g of dried cotton stalks, stirring uniformly, soaking for 3h at room temperature, placing in a tube furnace, heating to 800 ℃ under the protection of nitrogen for activation for 1h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 167.50 mg/g.

Comparative example 1:

pickling sawdust at normal temperature, washing with water, and drying at 110 deg.C; adding 10g of dried sawdust into 40g of phosphoric acid solution with the mass fraction of 55%, uniformly stirring, putting into a 140 ℃ oven for heat treatment for 1.5h, then putting into a tubular furnace, heating to 450 ℃ under the protection of nitrogen for activation for 1h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 136.25 mg/g.

Comparative example 2:

pickling and washing sawdust at normal temperature, drying 10g of dried sawdust at 110 ℃, adding 30g of zinc nitrate solution with the mass fraction of 5%, uniformly stirring, soaking for 3h at room temperature, placing in a tubular furnace, heating to 800 ℃ under the protection of nitrogen, activating for 2h, cooling to room temperature, pickling and washing in sequence until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 167.50 mg/g.

Comparative example 3:

crushing and screening cotton stalks into particles of 1-2 mm, pickling and washing at normal temperature, and drying at 110 ℃; adding 10g of dried cotton stalks into 30g of 15 mass percent zinc nitrate solution, uniformly stirring, soaking at room temperature for 3h, then placing in a tubular furnace, heating to 800 ℃ under the protection of nitrogen for activation for 1h, cooling to room temperature, then sequentially carrying out acid washing and water washing until the pH value of the solution is neutral, and drying to obtain the activated carbon. The activated carbon is used for Hg²⁺The adsorption capacity was 103.75 mg/g.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.