CN112265990A

CN112265990A - Preparation method and application of furfural residue porous activated carbon material

Info

Publication number: CN112265990A
Application number: CN202011140792.4A
Authority: CN
Inventors: 乔岩; 郭晓樱; 王英雄
Original assignee: Shanxi Institute of Coal Chemistry of CAS
Current assignee: Shanxi Institute of Coal Chemistry of CAS
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2021-01-26

Abstract

The invention discloses a preparation method and application of a furfural residue porous activated carbon material. The invention takes the waste biomass resource furfural residues with rich sources as raw materials, has low cost, simple and easy production process, is easy to industrialize, can bring good economic benefit and is beneficial to full utilization of biological resources. The furfural residue capacitor material prepared by the invention has excellent energy density and power density, is an ideal supercapacitor electrode material, and has good application prospects in the fields of power substations, electric automobile storage batteries, water purification and the like.

Description

Preparation method and application of furfural residue porous activated carbon material

Technical Field

The invention belongs to the field of development and utilization materials of waste biomass resources, and particularly relates to a preparation method and application of a furfural residue porous activated carbon material.

Background

With the rapid development of global industry and socioeconomic industry, the use of renewable biomass as a carbon source to replace the increasingly depleted fossil fuels has become an important development direction. Because the biomass is low in price and wide in source, the biomass, especially the waste agriculture and forestry biomass, is used as a raw material for preparing the porous carbon material and is an important component in the field of porous carbon material research in the future.

The ideal porous carbon for the supercapacitor not only has high specific surface area, porosity and graphitization degree, but also needs to have a multi-scale controllable microstructure to ensure rapid ion infiltration and transmission. The plant has rich and multi-layer structure, which is favorable for the transmission of ions and the quick transmission of nutrition. Different biomass raw materials have different cell tissue structure characteristics. Natural biomass has a fine structure that is artificially not synthesized. The natural multi-scale structure can endow the biomass carbon material with better electrochemical performance if the natural multi-scale structure can be well reserved. However, most of the current researches only focus on how to obtain porous carbon with higher specific surface area, so that the natural structure of the biomass itself is not fully utilized.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the furfural residue porous activated carbon which has a large specific surface area and rich micropores and mesoporous structures.

The technical scheme for solving the technical problems is as follows:

the preparation method of the furfural residue porous activated carbon is characterized by comprising the following steps of:

step 1, pretreatment: crushing, screening and drying the furfural residues or modified furfural residues to obtain a furfural residue or modified furfural residue powder raw material;

step 2, pre-carbonization treatment: heating the furfural residue or modified furfural residue powder raw material to a pre-carbonization temperature under the protection of inert gas, and then preserving heat;

step 3, activation treatment: carrying out chemical activation or physical activation treatment on the furfural residue or modified furfural residue powder pre-carbonized in the step 2;

and 4, washing: and (4) washing the activated product in the step (3) by an acid solution and deionized water in sequence, and filtering and drying to obtain the furfural residue porous activated carbon.

Further, the modified furfural residue in the step 1 is obtained by mixing, stirring and modifying furfural residue and methanol solution according to a mass ratio of 1:5, filtering and drying. The furfural residue mainly comprises cellulose, lignin, volatile organic compounds and ash. In order to reduce the negative influence of humus generated by volatile organic compounds as much as possible, methanol pretreatment is adopted to remove the volatile organic compounds, and modified furfural residues are obtained.

Further, in the step 2, the pre-carbonization temperature is 260-500 ℃, the heating rate is 1-5 ℃/min, and the heat preservation time is 1-2 h. By adopting the temperature and the temperature rise rate range for pre-carbonization, the volatile substances of the furfural residues or the modified furfural residues can be fully reacted, dehumidified and fully pre-carbonized.

Further, in the step 3, the chemical activation is to mix the pre-carbonized furfural residue or modified furfural residue powder with an activating agent, perform high-temperature activation treatment under the protection of inert gas, and then cool the mixture to normal temperature under the protection atmosphere.

Further, the temperature of the chemical activation treatment is 800-900 ℃, the heating rate is 1-5 ℃/min, and the heat preservation time is 1-2 h; the activating agent is potassium hydroxide, and the mass ratio of the activating agent to the furfural residue or the pre-carbonization product of the modified furfural residue powder is 1-3: 1 and mixing. Within the temperature and temperature rise rate range, the furfural residue or the modified furfural residue can be fully activated to obtain more action sites. The activating agent in the mass ratio range is beneficial to the furfural residues or modified furfural residues to generate a large number of pore structures in the activation process, the high specific surface area can be greatly improved, and the structural instability of the carbon material can be caused by the excessive mass specific gravity of KOH, so that the circulation stability of the carbon material is influenced.

Further, in the step 3, the physical activation is that at the pre-carbonization temperature, carbon dioxide gas is introduced into the pre-carbonized furfural residue or modified furfural residue powder for activation treatment, and then the temperature is reduced to normal temperature under the inert gas protective atmosphere. The temperature of the physical activation treatment is 500-1000 ℃, the heating rate is 1-5 ℃/min, and the heat preservation time is 1-2 h. The carbon dioxide is used as physical activation gas, so that the biomass porous effective structure of the furfural residue or modified furfural residue can be effectively maintained.

Further, the crushing is completed by adopting a high-energy crusher, and the condition parameters in the crushing process are as follows: the rotating speed is 1000r/min to 3000r/min, and the time is 1min to 3 min; the sieve adopts a 150-mesh sieve. The furfural residue or modified furfural residue raw material in the particle size range can increase the contact area between the raw material and an activating agent or activating gas, so that the activating process is more uniform and sufficient.

Further, the acidic solution in the step 4 is hydrochloric acid, and the concentration is 0.5-2 mol/L. The hydrochloric acid in the concentration range can make the activated furfural residue or the modified furfural residue porous activated carbon be neutral.

The specific surface area of the porous activated carbon for furfural residue provided by the invention is 1583-2600 m²The pore diameter is mainly micropores and mesopores distributed in the range of 1-10 nanometers.

A preparation method of furfural residue porous activated carbon is characterized by comprising the following steps: the activated carbon is prepared by taking furfural residues or modified furfural residues as raw materials, crushing, sieving and drying the raw materials, heating the raw materials to a carbonization temperature under the protection of inert gas, preserving heat at the carbonization temperature, cooling the raw materials to room temperature, and then washing, filtering and drying the carbonized furfural residues or modified furfural residues by deionized water.

Further, the modified furfural residue is obtained by mixing, stirring and modifying furfural residue and a methanol solution, filtering and drying.

Further, the carbonization temperature is 750-900 ℃, the heating rate is 1-5 ℃/min, and the heat preservation time is 1-2 h. By adopting the temperature and the temperature rise rate range for carbonization, the furfural residue or the modified furfural residue can be fully carbonized to obtain the porous activated carbon of the furfural residue or the modified furfural residue.

Further, the crushing is completed by adopting a high-energy crusher, and the condition parameters in the crushing process are as follows: the rotating speed is 1000r/min to 3000r/min, and the time is 1min to 3 min; the sieve adopts a 150-mesh sieve. The high-energy pulverizer can be used for locally destroying the furfural slag or the modified furfural slag under the action of mechanical force and forming various defects, so that the internal energy of the furfural slag or the modified furfural slag is increased, and the reaction activity in the pre-carbonization process is improved. The furfural residue or modified furfural residue raw material in the particle size range can increase the contact area between the raw material and an activating agent or activating gas, so that the activating process is more uniform and sufficient.

The furfural residue porous activated carbon provided by the invention is applied to electrode materials of capacitors or super capacitors.

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

1. the invention adopts the furfural residue biomass as the carbon source, has wide raw material source, low cost and high generated economic benefit.

2. The preparation method of the furfural residue porous activated carbon has the advantages of simple operation, short production period, reliability, environmental protection and meeting the requirement of industrial production.

3. The furfural residue capacitor material prepared by the method has the characteristics of excellent energy density and power density, no toxicity or harm in the using process and long cycle service life, is an ideal supercapacitor electrode material, and has good application prospects in the fields of power substations, electric vehicle storage batteries, water purification and the like.

Description of the drawings:

FIG. 1 is a Scanning Electron Microscope (SEM) image of a furfural residue porous activated carbon material prepared in example 1 of the invention;

fig. 2 is a nitrogen adsorption and desorption curve diagram of the furfural residue porous activated carbon material prepared in example 1 of the invention;

FIG. 3 is a pore size distribution graph of a furfural residue porous activated carbon material prepared in example 1 of the present invention;

FIG. 4 is a Cyclic Voltammetry (CV) graph of a furfural residue porous activated carbon material electrode prepared in example 1 of the present invention at a sweep rate of 500 mV/s;

fig. 5 is a constant current charge-discharge curve (GCD) diagram of the furfural residue porous activated carbon material electrode prepared in example 1 of the present invention under different current densities.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The embodiments are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are given, but the scope of the present invention is not limited to the embodiments.

Example 1

The preparation method of the furfural residue porous activated carbon material comprises the following steps:

(1) modification treatment: mixing and stirring furfural residues and a methanol solution according to a mass ratio of 1:5, filtering, and drying in an oven at 105 ℃ for 12 hours to obtain modified furfural residues;

(2) pretreatment: crushing the modified furfural residues in a high-energy crusher (the rotating speed is 2000r/min, the time is 1min), and then sieving the crushed furfural residues through a 150-mesh sieve;

(3) pre-carbonization: weighing 20g of the modified furfural residue powder in the step (2), placing the powder in a tube furnace, heating to 500 ℃ at a speed of 5 ℃/min under the argon atmosphere, preserving the heat for 1h, naturally cooling to room temperature, and taking out a sample;

(4) and (3) activation: mixing the modified furfural residue powder pre-carbonized in the step (3) with potassium hydroxide according to a mass ratio of 1: 3, uniformly mixing the materials in an alumina crucible, drying the materials in a hot air oven at 105 ℃ for 12 hours, putting the materials into a tube furnace, heating the materials to 800 ℃ at 3 ℃/min under the argon atmosphere, preserving the heat for 1 hour, naturally cooling the materials to room temperature, and taking out a sample;

(5) washing: and (4) washing the product obtained in the step (4) with 2mol/L hydrochloric acid for 1 time and deionized water for 3 times in sequence until the product is neutral, then filtering, and carrying out vacuum drying at 60 ℃ for 12 hours to obtain the furfural residue porous activated carbon.

The specific surface area of the activated carbon prepared in this example was 1753.5m²(ii)/g; the morphology is characterized as shown in figure 1; as shown in the nitrogen adsorption and desorption curve of fig. 2, the activated carbon prepared in the embodiment has higher adsorption capacity between the relative pressure of 0.03 and 0.10; the micropores and the mesopores are more abundant, and the result is shown in a pore size distribution curve diagram 3; the prepared electrode plate is used for testing the capacitance performance, and the characterization of the capacitance performance is shown in figures 4 and 5Fig. 4 shows that the AFRM has the largest envelope, which means the highest specific capacitance. Furthermore, even at 500mV · s^-1A pseudo-rectangle can also be observed at high scanning frequencies, indicating that the material has good reversibility and a fast charge propagation speed. As can be seen from fig. 5, the electrochemical output of the AFRM is comparable to or better than other reported biomass carbon materials, showing excellent electrochemical performance.

Examples 2 to 3

A method for preparing a furfural residue porous activated carbon material, which is basically the same as in example 1, except that the rotation speed, the rotation time, the pre-carbonization heating rate, the pre-carbonization temperature, the pre-carbonization heat preservation time, the activation heating rate, the activation temperature, the activation time, the mass ratio of a pre-carbonization product to potassium hydroxide and the hydrochloric acid concentration parameters are shown in table 1.

Example 4

(1) pretreatment: crushing the furfural residues in a high-energy crusher (the rotating speed is 1000r/min, the time is 2min), and then sieving the crushed furfural residues with a 150-mesh sieve;

(2) pre-carbonization: weighing 16g of furfural residue powder obtained in the step (1), placing the furfural residue powder in a tube furnace, heating to 500 ℃ at a speed of 5 ℃/min under the argon atmosphere, preserving heat for 1h, naturally cooling to room temperature, and taking out a sample;

(3) and (3) activation: mixing the furfural residue powder pre-carbonized in the step (2) with potassium hydroxide according to a mass ratio of 1: 3, uniformly mixing the materials in an alumina crucible, drying the materials in a hot air oven at 105 ℃ for 12 hours, putting the materials into a tube furnace, heating the materials to 800 ℃ at 3 ℃/min under the argon atmosphere, preserving the heat for 1 hour, naturally cooling the materials to room temperature, and taking out a sample;

(4) washing: and (4) washing the product obtained in the step (3) with 2mol/L hydrochloric acid for 1 time and deionized water for 3 times in sequence until the product is neutral, then filtering, and carrying out vacuum drying at 60 ℃ for 12 hours to obtain the furfural residue porous activated carbon.

Examples 5 to 6

A method for preparing a furfural residue porous activated carbon material, which is basically the same as in example 4, except that the rotation speed, the rotation time, the pre-carbonization heating rate, the pre-carbonization temperature, the pre-carbonization heat preservation time, the activation heating rate, the activation temperature, the activation time, the mass ratio of the pre-carbonization product to potassium hydroxide and the hydrochloric acid concentration parameters are shown in table 1.

TABLE 1

Example 7

(1) modification treatment: mixing and stirring furfural residues and a methanol solution according to the mass ratio of 1:5, filtering, and drying in an oven at 105 ℃ for 12 hours to obtain modified furfural residues;

(2) pretreatment: crushing the modified furfural residues in a high-energy crusher (the rotating speed is 1000r/min, the time is 2min), and then sieving the crushed furfural residues with a 150-mesh sieve;

(3) pre-carbonization: weighing 20g of the modified furfural residue powder in the step (2), placing the powder in a tube furnace, heating to 450 ℃ at a speed of 5 ℃/min under the argon atmosphere, and preserving heat for 2 h;

(4) and (3) activation: heating the modified furfural residue powder pre-carbonized in the step (3) to 900 ℃ at a speed of 3 ℃/min under the argon atmosphere, performing high-temperature activation for 2h under a carbon dioxide atmosphere of 1L/min, naturally cooling to room temperature under the argon atmosphere, and taking out a sample;

(5) washing: and (4) washing the product obtained in the step (4) with 2mol/L hydrochloric acid for 1 time and deionized water for 4 times in sequence until the product is neutral, then filtering, and carrying out vacuum drying at 60 ℃ for 12 hours to obtain the furfural residue porous activated carbon.

Examples 8 to 9

A method for preparing a furfural residue porous activated carbon material, which is basically the same as in example 7, except that the rotation speed, the rotation time, the pre-carbonization heating rate, the pre-carbonization temperature, the pre-carbonization heat preservation time, the activation heating rate, the activation temperature, the activation time, and CO of a high-energy pulverizer are used₂Flow rate and hydrochloric acid concentration parameters, detailsSee table 2.

Example 10

(1) pretreatment: crushing the furfural residues in a high-energy crusher (the rotating speed is 2000r/min, the time is 1min), and then sieving the crushed furfural residues with a 150-mesh sieve;

(2) pre-carbonization: weighing 18g of furfural residue powder in the step (1), placing the furfural residue powder in a tube furnace, heating to 400 ℃ at a speed of 4 ℃/min under an argon atmosphere, and preserving heat for 1 h;

(3) and (3) activation: heating the furfural residue powder pre-carbonized in the step (2) to 900 ℃ at a speed of 5 ℃/min under the argon atmosphere, performing high-temperature activation for 1h under a carbon dioxide atmosphere of 2L/min, naturally cooling to room temperature under the argon atmosphere, and taking out a sample;

Examples 11 to 12

A method for preparing a furfural residue porous activated carbon material, which is substantially the same as in example 10, except that the rotational speed, the rotational time, the pre-carbonization temperature rise rate, the pre-carbonization temperature, the pre-carbonization heat preservation time, the activation temperature rise rate, the activation temperature, the activation time, and CO of a high-energy pulverizer are used₂Flow rate and hydrochloric acid concentration parameters are detailed in table 2.

TABLE 2

Example 13

(2) pretreatment: crushing the modified furfural residues in a high-energy crusher (the rotating speed is 1000r/min, the time is 1min), and then sieving the crushed furfural residues with a 150-mesh sieve;

(3) carbonizing: weighing 20g of the modified furfural residue powder in the step (2), placing the powder in a tube furnace, heating to 500 ℃ at a speed of 5 ℃/min under the argon atmosphere, preserving heat for 1h, heating to 800 ℃ at a speed of 3 ℃/min, preserving heat for 1h, naturally cooling to room temperature, and taking out a sample;

(4) washing: and (4) washing the product in the step (3) with deionized water for 5 times, filtering, and performing vacuum drying at 60 ℃ for 12 hours to obtain the furfural residue porous activated carbon.

Examples 14 to 15

A method for preparing a furfural residue porous activated carbon material, which is basically the same as in example 13, except that parameters of the high-energy pulverizer rotation speed, the rotation time, the carbonization temperature, the temperature rise rate and the activation time are as shown in table 3.

Example 16

(1) pretreatment: crushing the modified furfural residues in a high-energy crusher (the rotating speed is 1500r/min, the time is 1min), and then sieving the crushed furfural residues with a 150-mesh sieve;

(2) carbonizing: weighing 18g of the modified furfural residue powder in the step (2), placing the powder in a tube furnace, heating to 500 ℃ at a speed of 5 ℃/min under the argon atmosphere, preserving heat for 1h, heating to 800 ℃ at a speed of 3 ℃/min, preserving heat for 1h, naturally cooling to room temperature, and taking out a sample;

(3) washing: and (4) washing the product in the step (3) with deionized water for 6 times, filtering, and carrying out vacuum drying at 60 ℃ for 12 hours to obtain the furfural residue porous activated carbon.

Examples 17 to 18

A method for preparing a furfural residue porous activated carbon material, which is basically the same as in example 16, except that parameters of the rotation speed, the rotation time, the carbonization temperature, the temperature rise rate and the activation time of a high-energy pulverizer are as shown in table 3.

TABLE 3

Claims

1. a preparation method of furfural residue porous activated carbon, is characterized in that, comprises the following steps:

Step 1, pretreatment: after the furfural residue or modified furfural residue is pulverized, sieved and dried, furfural residue or modified furfural residue powder raw material is obtained;

Step 2, pre-carbonization treatment: heating the furfural slag or modified furfural slag powder raw material to the pre-carbonization temperature under the protection of an inert gas and then keeping the temperature;

Step 3, activation treatment: chemical activation or physical activation treatment is carried out on the pre-carbonized furfural residue or modified furfural residue powder in step 2;

Step 4, washing: the activated product in step 3 is washed with acid solution and deionized water in sequence, and after filtration and drying, furfural residue porous activated carbon is obtained.

2. the preparation method of a kind of furfural residue porous activated carbon according to claim 1, is characterized in that: in described step 1, the modified furfural residue is that after furfural residue and methanol solution are mixed and stirred for modification, the result is obtained by filtration and drying.

3. the preparation method of a kind of furfural residue porous activated carbon according to claim 1, is characterized in that: in described step 2, the pre-carbonization temperature is 260～500 ℃, the heating rate is 1～5 ℃/min, and the holding time is 1 to 2 hours.

4. the preparation method of a kind of furfural slag porous activated carbon according to claim 1, is characterized in that: in described step 3, chemical activation is to mix pre-carbonized furfural slag or modified furfural slag powder with activator, and High temperature activation treatment is carried out under the protection of inert gas, and then the temperature is lowered to normal temperature in a protective atmosphere.

5. the preparation method of a kind of furfural residue porous activated carbon according to claim 4, is characterized in that: the temperature of described chemical activation treatment is 800～900 ℃, the temperature rise rate is 1～5 ℃/min, and the holding time is 1 ~2h.

6. the preparation method of a kind of furfural slag porous activated carbon according to claim 4, is characterized in that: described activator is potassium hydroxide, and the carbonization product of described activator and furfural slag or modified furfural slag powder presses The mass ratio is 1~3:1 mixing.

7. the preparation method of a kind of furfural slag porous activated carbon according to claim 1, is characterized in that: in described step 3, physical activation is under pre-carbonization temperature, by pre-carbonized furfural slag or modified furfural slag powder Carbon dioxide gas is introduced for activation treatment, and the flow rate of the activation gas into the furnace is 1L/min～5L/min, and then the temperature is lowered to normal temperature in an inert gas protective atmosphere.

8. the preparation method of a kind of furfural residue porous activated carbon according to claim 7, is characterized in that: the temperature of physical activation treatment in described step 3 is 500～1000 ℃, the temperature rise rate is 1～5 ℃/min, high temperature The activation time is 1-2h.

9. the preparation method of a kind of furfural residue porous activated carbon according to claim 1, is characterized in that: in described step 1, pulverization adopts high-energy pulverizer to complete, and the condition parameter of pulverization process is: rotating speed is 1000r/min～3000r/ min, and the time is 1 min to 3 min; the sieving adopts a 150-mesh sieve.

10 . The preparation method of furfural residue porous activated carbon according to claim 1 , wherein the acid solution in the step 4 is hydrochloric acid, and the concentration is 0.5-2 mol/L. 11 .

11. A kind of furfural residue porous activated carbon according to claim 1 is characterized in that: the specific surface area of the furfural residue porous activated carbon is 1583～2600m ² /g, and the pore diameter is distributed in the range of 1～10 nanometers with micropores and mesopores. Mainly holes.

12. a preparation method of furfural slag porous activated carbon, it is characterized in that: described activated carbon is with furfural slag or modified furfural slag as raw material, after pulverizing, sieving and drying, be warming up to carbonization temperature under inert gas protection, in The carbonized furfural residue or the modified furfural residue is prepared by washing, filtering and drying with deionized water after being kept at the carbonization temperature and then cooled to room temperature.

13 . The method for preparing a furfural residue porous activated carbon according to claim 12 , wherein the modified furfural residue is obtained by filtration and drying after furfural residue and methanol solution are mixed and stirred for modification. 14 .

14 . The preparation method of furfural residue porous activated carbon according to claim 12 , wherein the carbonization temperature is 750-900° C., the heating rate is 1-5° C./min, and the holding time is 1-2 h. 15 .

15. The preparation method of a furfural slag porous activated carbon according to claim 12, characterized in that: the pulverization is completed by a high-energy pulverizer, and the conditional parameters of the pulverization process are: the rotating speed is 1000r/min～3000r/min, the time It is 1min to 3min; the sieving adopts a 150-mesh sieve.

16. The application of the furfural residue porous activated carbon according to any one of claims 1 to 15, characterized in that: it is applied to capacitor or supercapacitor electrode material.