阅读说明：本技术 一种磷酸锌-有机酸复合活化剂及采用该活化剂制备活性炭的方法 (Zinc phosphate-organic acid composite activator and method for preparing activated carbon by using same ) 是由 王静 张春明 张奥杰 徐景涛 郭子彰 张成禄 于 2019-12-04 设计创作，主要内容包括：本发明提供一种磷酸锌-有机酸复合活化剂及采用该活化剂制备活性炭的方法,所述磷酸锌-有机酸复合活化剂包括磷酸锌和有机酸,所述有机酸为乙酸、乳酸、丙酮酸、丙酸、丁酸、异丁酸、甲基磺酸和乙基磺酸的任意一种或几种。采用上述磷酸锌-有机酸复合活化剂制备活性炭的方法包括(1)有机原料处理,(2)混合浸渍,(3)炭化活化,(4)清洗,(5)过滤、干燥：使用该复合活化剂和上述方法制得的活性炭,碘吸附量可达到1135mg/g,比表面积可达1129m<Sup>2</Sup>/g,并且,在制备活性炭的活化过程中,加入了有机酸,增加了含氧官能团,提高了活性炭的吸附性能,不需要在制备过程之外,另外进行氧化改性,简化了步骤。(The invention provides a zinc phosphate-organic acid composite activator and a method for preparing activated carbon by adopting the same. The method for preparing the activated carbon by adopting the zinc phosphate-organic acid composite activator comprises the following steps of (1) organic raw material treatment, (2) mixed impregnation, (3) carbonization and activation, (4) cleaning, (5) filtering and drying: the iodine adsorption amount of the active carbon prepared by the composite activator and the method can reach 1135mg/g, and the specific surface area can reach 1129m 2 And in addition, in the activation process of preparing the activated carbon, the organic acid is added, oxygen-containing functional groups are added, the adsorption performance of the activated carbon is improved, and oxidation modification is not required to be carried out outside the preparation process, so that the steps are simplified.)

1. A zinc phosphate-organic acid composite activator is characterized by comprising zinc phosphate and organic acid.

2. The zinc phosphate-organic acid composite activator according to claim 1, wherein the organic acid is one or more selected from the group consisting of acetic acid, lactic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, methanesulfonic acid and ethanesulfonic acid.

3. The zinc phosphate-organic acid composite activator according to claim 1, wherein the organic acid is acetic acid, lactic acid, and pyruvic acid at a mass ratio of 1: 1:1 in the composition of claim 1.

4. The zinc phosphate-organic acid complex activator according to any one of claims 1 to 3, wherein the zinc phosphate is dissolved in an organic acid to form a solution in which the concentration of zinc phosphate is: 1 to 4 wt%.

5. A method for preparing active carbon by adopting zinc phosphate-organic acid composite activating agent is characterized in that,

in the preparation process of the activated carbon, the zinc phosphate-organic acid composite activator in any one of claims 1 to 4 is used as the activator;

further, the organic raw material is any one or more of fruit shell, straw, wood, coal and resin;

furthermore, the straw is one or more of corn straw, wheat straw, rice straw and soybean straw.

6. The method for preparing activated carbon using zinc phosphate-organic acid composite activator according to claim 5, comprising the steps of:

(1) organic raw material treatment: drying and crushing the organic raw materials, sealing, drying and storing to obtain organic raw material powder;

(2) mixing and dipping: mixing and impregnating the organic raw material powder obtained in the step (1) with the zinc phosphate-organic acid composite activator according to any one of claims 1 to 4;

(3) carbonization and activation: heating the organic raw material powder impregnated in the step (2) to a carbonization temperature, keeping, cooling, taking out to obtain activated carbon,

the carbonization temperature is 500-750 ℃;

(4) cleaning: cleaning the activated carbon obtained in the step (3) until the pH of the supernatant is 6.5-7.0;

(5) filtering and drying:

and (4) filtering and drying the activated carbon cleaned in the step (4) to obtain an activated carbon product.

7. The method for preparing activated carbon using zinc phosphate-organic acid composite activator according to claim 6, wherein the zinc phosphate-organic acid composite activator is selected from the group consisting of zinc phosphate-organic acid composite activator,

the step (1) is as follows:

(1) vacuum drying the organic raw materials at 105 ℃, crushing the organic raw materials by using a plant crusher, sieving the crushed organic raw materials by using a 50-100-mesh sieve to obtain organic raw material powder, sealing, drying and storing.

8. The method for preparing activated carbon using zinc phosphate-organic acid composite activator according to claim 6, wherein the zinc phosphate-organic acid composite activator is selected from the group consisting of zinc phosphate-organic acid composite activator,

the mass ratio of the organic raw material powder to the zinc phosphate-organic acid composite activator in the step (2) is 1 (1-3);

and (3) soaking for 6-12 hours in the step (2).

9. The method for preparing activated carbon using zinc phosphate-organic acid composite activator according to claim 6, wherein the zinc phosphate-organic acid composite activator is selected from the group consisting of zinc phosphate-organic acid composite activator,

the step (3) is as follows: and (3) transferring the organic raw material powder impregnated in the step (2) to a crucible, putting the crucible into a muffle furnace, heating to 500-750 ℃, keeping the temperature for 30-90 minutes, cooling, and taking out to obtain the activated carbon.

10. The method for preparing activated carbon using zinc phosphate-organic acid composite activator according to claim 6, wherein the zinc phosphate-organic acid composite activator is selected from the group consisting of zinc phosphate-organic acid composite activator,

the step (5) is as follows:

(5) filtering and drying: and (3) pumping and filtering the activated carbon cleaned in the step (4) by using a Buchner funnel, discarding the pumped filtrate, putting the sample into a vacuum drying oven at 100-110 ℃, and drying for 4-6 hours to obtain an activated carbon product.

Technical Field

The invention belongs to the technical field of porous carbon preparation, and relates to a zinc phosphate-organic acid composite activator and a method for preparing activated carbon by adopting the composite activator through one-step carbonization and activation.

Background

The Active Carbon (AC) mainly contains carbon and a small amount of elements such as oxygen, hydrogen, sulfur, nitrogen, chlorine and the like, is a classical adsorption material with a high specific surface area and a rich pore structure, has strong adsorption performance, and is an industrial adsorbent with wide application. Currently, activated carbon has been widely used in downstream industries such as food industry, water treatment, chemical industry, pharmaceutical industry, environmental protection industry, metallurgical industry, national defense industry, and the like. With the economic development and the improvement of the living standard of people, people put forward higher requirements on the safety, the purity and other standards of food, medicines and drinking water, and the market demand of the activated carbon is continuously expanded. According to the material, the active carbon can be divided into: wood active carbon, shell active carbon, coal active carbon, petroleum active carbon, regenerated carbon and mineral substance raw material active carbon. The preparation of the activated carbon with excellent adsorption performance by using forestry 'three residues' (felling residues, lumber making residues and processing residues) and crop straws and other raw materials meets the requirement of circular economy.

The preparation method of the activated carbon generally comprises a chemical activation method and a physical activation method, wherein the chemical activation method is to prepare the activated carbon by uniformly mixing various carbon-containing raw materials and chemicals, and then carrying out the processes of carbonization, activation, chemical recovery, rinsing, drying and the like at a certain temperature. Phosphoric acid, zinc chloride, potassium hydroxide, sodium hydroxide, sulfuric acid, potassium carbonate, polyphosphoric acid, phosphate esters and the like can be used as activating reagents, and although the chemical reactions are different, some have erosion, hydrolysis or dehydration effects on raw materials and some have oxidation effects, the chemicals can promote the activation of the raw materials to a certain extent, wherein phosphoric acid, zinc chloride and potassium hydroxide are the most commonly used activating agents. Compared with a physical activation method, the activated carbon prepared by the chemical activation method has higher specific surface and better adsorption performance, and various functional groups formed after chemical activation and modification can meet the desorption requirement after adsorption saturation to achieve the aim of recycling, thereby being beneficial to the development of novel activated carbon products. In recent years, new technologies for preparing activated carbon are continuously appearing at home and abroad, and the main research directions comprise reduction of preparation cost, simplification of preparation process, improvement of adsorption performance and yield and the like. Among them, how to prepare activated carbon having a high specific surface area using waste biomass has been a hot point of research.

The paper published in the university journal of Zhongnan "on the influence of organic acid modification on the adsorption and regeneration of activated carbon and methanol thereof" discloses that the modified activated carbon is prepared by using granular activated carbon as a raw material and 3 kinds of organic acids (oxalic acid, tartaric acid and citric acid) as modifiers. After the activated carbon is prepared, the prepared activated carbon is modified by organic acid, so that the BET specific surface area and the total pore volume of the activated carbon are reduced, uneven rough etching marks are formed on the surface, and more oxygen-containing functional groups such as O-H, C-O and the like are generated on the surface along with the generation of white crystal particles.

The Lianxin academic thesis of the university in Central and south China "research on adsorption behavior of organic acid modified activated carbon and VOCs thereof", wherein the method discloses that organic acid (oxalic acid, sulfamic acid and tartaric acid) is used for modifying the activated carbon, and after modification, the pore structure parameters of the activated carbon are reduced to different degrees; the surface of the active carbon is rough in shape, has etched traces and presents an uneven structure; new more oxygen-containing functional groups are formed on the surface of the activated carbon.

The paper "acetone adsorption research by organic acid modified activated carbon" discloses that commercial activated carbon is used as a raw material, and 3 organic acids (formic acid, oxalic acid and sulfamic acid) are used as modifiers to prepare the modified activated carbon. After modification, the BET specific surface area and the total pore volume of the activated carbon are reduced, uneven and rough etching marks are formed on the surface, and more oxygen-containing functional groups such as O-H, C (O, C-O, S) are formed on the surface along with the generation of white crystal particles.

Disclosure of Invention

The invention takes crop straws as raw materials, and prepares the activated carbon with high adsorption performance by a zinc phosphate-organic acid combined activation methodThe specific surface area of the prepared activated carbon can reach 900-1200 m²·g^-1The iodine adsorption amount determined according to the national standard (GB/T12496.8-2015) can reach 1135mg/g, and the preparation method is simple in preparation process and wide in industrial prospect, and provides technical support for resource recycling of crop straws and environmental protection.

Specifically, the technical scheme adopted by the invention is as follows:

a zinc phosphate-organic acid composite activator comprises zinc phosphate and an organic acid.

The organic acid can promote the pore formation of the activated carbon and increase the function of oxygen-containing functional groups on the surface of the activated carbon.

Further, the organic acid is any one or more of acetic acid, lactic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, methanesulfonic acid and ethylsulfonic acid. For example, the organic acid may be any one of acetic acid, lactic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, methanesulfonic acid, and ethanesulfonic acid, or a combination of acetic acid and lactic acid, or a combination of lactic acid and propionic acid, or a combination of acetic acid and pyruvic acid, or a combination of acetic acid, lactic acid, and pyruvic acid, or any three of the above-mentioned combinations, any four of the above-mentioned combinations, any six of the above-mentioned combinations, any seven of the above-mentioned combinations, or any eight of the above-mentioned combinations.

Preferably, the ratio of the organic acid to acetic acid, lactic acid and pyruvic acid is 1: 1:1.

further, the zinc phosphate is dissolved in an organic acid to form a solution in which the concentration of zinc phosphate is: 1 to 4 wt%. For example, the concentration of zinc phosphate may be 1 (wt)%, 1.1 (wt)%, 1.2 (wt)%, 1.3 (wt)%, 1.4 (wt)%, 1.5 (wt)%, 2 (wt)%, 3 (wt)%, 4 (wt)% and the like.

The invention also discloses a preparation method for preparing the activated carbon by adopting the zinc phosphate-organic acid composite activator, wherein in the preparation process of the activated carbon, the zinc phosphate-organic acid composite activator is adopted as the activator;

the preparation method for preparing the activated carbon is not limited, and in the prior art, the preparation method for preparing the activated carbon by activating the acidic chemical activating agent can adopt the zinc phosphate-organic acid composite activating agent;

further, the organic raw material is any one or more of fruit shell, straw, wood, coal and resin.

The raw materials are commonly used in the preparation of the activated carbon.

The shell can be agricultural waste such as coconut shell, peach shell, walnut shell, jujube shell, etc. The wood can be wood of various trees, and can also be wood harvesting residues, wood making residues, processing residues and the like.

Furthermore, the straw is one or more of corn straw, wheat straw, rice straw and soybean straw.

As a preferred technical scheme, the preparation method comprises the following steps:

(1) organic raw material treatment: drying and crushing the organic raw materials, sealing, drying and storing to obtain organic raw material powder;

(2) mixing and dipping: mixing the organic raw material powder obtained in the step (1) with the zinc phosphate-organic acid composite activator, and dipping;

(3) carbonization and activation: heating the organic raw material powder impregnated in the step (2) to a carbonization temperature, keeping, cooling, taking out to obtain activated carbon,

the carbonization temperature is 500-750 ℃; for example, the temperature may be 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃ or the like.

(4) Cleaning: cleaning the activated carbon obtained in the step (3) until the pH of the supernatant is 6.5-7.0;

(5) filtering and drying:

and (4) filtering and drying the activated carbon cleaned in the step (4) to obtain an activated carbon product.

Further, the air conditioner is provided with a fan,

the step (1) is as follows:

(1) vacuum drying the organic raw materials at 105 ℃, crushing the organic raw materials by using a plant crusher, sieving the crushed organic raw materials by using a 50-100-mesh sieve to obtain organic raw material powder, sealing, drying and storing.

The invention does not limit the proportion of the organic raw material powder and the zinc phosphate-organic acid composite activator, and as a further preferable scheme, the mass ratio of the organic raw material powder to the zinc phosphate-organic acid composite activator in the step (2) is 1 (1-3);

and (3) soaking for 6-12 hours in the step (2). For example, 6h, 7h, 7.5h, 8h, 9h, 10h, 11h, 12h, etc.

Further, the air conditioner is provided with a fan,

the step (3) is as follows: and (3) transferring the organic raw material powder impregnated in the step (2) to a crucible, putting the crucible into a muffle furnace, heating to 500-750 ℃, keeping the temperature for 30-90 minutes, cooling, and taking out to obtain the activated carbon.

Further, the air conditioner is provided with a fan,

the step (5) is as follows:

(5) filtering and drying: and (3) pumping and filtering the activated carbon cleaned in the step (4) by using a Buchner funnel, discarding the pumped filtrate, putting the sample into a vacuum drying oven at 100-110 ℃, and drying for 4-6 hours to obtain an activated carbon product.

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

(1) the method takes organic raw materials (such as straws, fruit shells, wood, coal and resin) as materials, prepares the activated carbon by using a zinc phosphate and organic acid combined activation technology, has simple preparation process, high product yield (27.1-32.6 percent), developed pores, large specific surface area and strong adsorption effect, is an industrial adsorbent with wide application and excellent performance, specifically, the iodine adsorption quantity measured according to the national standard (GB/T12496.8-2015) can reach 1135mg/g, is higher than the quality index of the national first-grade activated carbon for wooden water purification (GB/T13803.2-1999), and the specific surface area can reach 1129m²/g。

(2) According to the preparation method, in the activation process of preparing the activated carbon, the organic acid is added, the oxygen-containing functional group is added, the adsorption performance of the activated carbon is improved, the preparation process is not required, oxidation modification is additionally carried out, the steps are simplified, and the preparation method is used in industrial production and greatly reduces the production cost.

Drawings

FIG. 1 is a SEM photograph of a product obtained in example 15.

Detailed Description

The present invention is further illustrated by the following specific examples, it should be noted that, for those skilled in the art, variations and modifications can be made without departing from the principle of the present invention, and these should also be construed as falling within the scope of the present invention.