BIO-OIL LIGHT FRACTION-BASED BREAD-SHAPED POROUS ACTIVATED CARBON, METHOD FOR PREPARING THE SAME AND USE THEREOF
20220259049 · 2022-08-18
Assignee
Inventors
- Shurong WANG (Hangzhou, CN)
- Yan DING (Hangzhou, CN)
- Lingjun ZHU (Hangzhou, CN)
- Kunzan Qiu (Hangzhou, CN)
- Yunchao LI (Hangzhou, CN)
- Jingsong ZHOU (Hangzhou, CN)
Cpc classification
C01B32/33
CHEMISTRY; METALLURGY
C01B32/342
CHEMISTRY; METALLURGY
Y02E60/13
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
International classification
Abstract
A bio-oil light fraction-based bread-shaped porous activated carbon, a method for preparing the same and use thereof are provided. A light fraction prepared by fast pyrolysis of a biomass coupled with molecular distillation is selected as a precursor; an activator is directly mixed with the light fraction and stirred to obtain a homogeneous liquid; then, the homogeneous liquid is subjected to one-step carbonization and activation at a two-stage temperature in an inert atmosphere; after the activation, the obtained solid was washed and filtered, the activator reaction products and impurities are removed, and then dried to obtain the activated carbon used as an electrode carbon material of a supercapacitor. The method fully utilizes the rich micromolecule compounds such as water, acids, ketones, aldehydes, monophenols and the like in the obtained light fraction, and the micromolecule compounds and water can interact with the activator.
Claims
1. A method for preparing a bio-oil light fraction-based bread-shaped porous activated. carbon, comprising the following steps of: carrying out molecular distillation on pyrolyzed bio-oil to obtain a light fraction, wherein the light fraction is in a liquid phase; using the light fraction as a carbon precursor raw material, and mixing an activator with the light fraction, wherein the activator is a water-soluble activator; mixing the light fraction with the activator to form a mixed solution; and carbonizing and activating the mixed solution to obtain the bio-oil light fraction-based bread-shaped porous activated carbon.
2. The method according to claim 1, wherein the step of carbonizing and activating involves multi-stage heating, and the mixed solution is subjected to one-step carbonization and activation.
3. The method according to claim 1, wherein the step of carbonizing and activating involves two-stage heating, and the mixed solution is subjected to one-step carbonization and activation.
4. The method according to claim 1, wherein the mixed solution is stirred by a magnetic stirrer to obtain a uniform mixed solution.
5. The method according to claim 1, specifically comprising the following steps: S1, firstly, preparing biomass fast pyrolyzed bio-oil, carrying out molecular distillation on the biomass fast pyrolyzed bin-oil to obtain the light fraction, then mixing the activator with the light fraction according to a predetermined mass ratio and stirring for a predetermined time to obtain a mixed homogeneous liquid of the light fraction and the activator, subjecting the mixed homogeneous liquid to two-stage heating and one-step carbonization and activation under a protection of an inert gas, and cooling to room temperature to obtain an impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon; S2, grinding the impurity-containing bin-oil light fraction-based bread-shaped porous activated carbon obtained in step S1 and sieving for the first time, washing and stirring with a hydrochloric acid solution, then repeatedly washing and suction filtering with deionized water until a filtrate is neutral, so as to remove activator reaction products and impurities in the solid product, drying, grinding again and sieving for the second time, and obtaining the bio-oil light fraction-based bread-shaped porous activated carbon.
6. The method according to claim 1, wherein the light fraction is obtained by preparing pyrolyzed bio-oil from a cellulose biomass by fast pyrolysis and then subjecting the pyrolyzed bio-oil to the molecular distillation.
7. The method according to according to claim 6, wherein the cellulose biomass is one or more selected from the group consisting of fruit shell, sawdust, straw, bamboo, walnut shell, poplar sawdust and corn straw.
8. The method according to according to claim 1, wherein the molecular distillation adopts a molecular distillation pressure of 10-3,000 Pa and a working pressure of a. short-range distiller of 0.001-1 mbar.
9. The method according to according to claim 1, wherein the light fraction comprises the following components in parts by mass: 15-50 parts of water, 20-30 parts of acids, 5-15 parts of ketones, 5-10 parts of aldehydes and 10-20 parts of monophenols.
10. The method according to claim 1, wherein, the activator is a solid water-soluble active metal alkali or a solid water-soluble active metal salt.
11. The method according to according to claim 10, wherein the activator is one or more selected from the group consisting of potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate and sodium bicarbonate.
12. The method according to claim 1, wherein a mass ratio of the activator to the light fraction is 1:22 to 1:3.
13. The method according to claim 5, wherein in step S1, the mixed homogeneous liquid of the light fraction and the activator is obtained by adding the activator with a predetermined mass ratio to the light fraction, quickly sealing a container, and stirring for 0.5-2 hours with a magnetic stirrer to obtain a uniform mixture.
14. The method according to claim 5, wherein in step S1, the inert gas is one or more selected from the group consisting of nitrogen, argon and helium.
15. The method according to claim 5, wherein conditions of the two-stage heating and the one-step carbonization and activation in step S1 are as follows: a first stage has a final heating temperature of 300-500° C., a heating rate of 2-10° C./min and a heating time of 0.5-3 hours, and a second stage has a final heating temperature of 700-900° C., a heating rate of 2-10° C./min and a heating time of 1-3 hours.
16. The method according to claim 5, wherein in step S2, after the sieving for the first time, the impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon is washed with a 0.5-2 M hydrochloric acid solution, stirred by a magnetic force for 3-6 hours, and then repeatedly washed with deionized water and filtered by suction.
17. A bio-oil light fraction-based bread-shaped porous activated carbon prepared by the method according to claim 1, wherein the bio-oil light fraction-based bread-shaped porous activated carbon has a three-dimensional porous structure with a density of 0.01-0.03 g/cm.sup.3, a specific surface area of 1,000-3,000 m.sup.2/g, a pore volume of 0.5-1.5 cm.sup.3/g, and an average pore size of 1.8-2.6 nm, and is free of ash.
18. A method of preparing an active material of a supercapacitor electrode or a material of a battery electrode, comprising: using the bio-oil light fraction-based bread-shaped porous activated carbon prepared by the method according to claim 1.
19. The method according to claim 2, specifically comprising the following steps: S1, firstly, preparing biomass fast pyrolyzed bio-oil, carrying out molecular distillation on the biomass fast pyrolyzed bio-oil to obtain the light fraction, then mixing the activator with the light fraction according to a predetermined mass ratio and stirring for a predetermined time to obtain a mixed homogeneous liquid of the light fraction and the activator, subjecting the mixed homogeneous liquid to two-stage heating and one-step carbonization and activation under a protection of an inert gas, and cooling to room temperature to obtain an impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon; S2, grinding the impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon obtained in step S1 and sieving for the first time, washing and stirring with a hydrochloric acid solution, then repeatedly washing and suction filtering with deionized water until a filtrate is neutral, so as to remove activator reaction products and impurities in the solid product, drying, grinding again and sieving for the second time, and obtaining the bio-oil light fraction-based bread-shaped porous activated carbon.
20. The method according to claim 3, specifically comprising the following steps: S1, firstly, preparing biomass fast pyrolyzed carrying out molecular distillation on the biomass fast pyrolyzed bio-oil to obtain the light fraction, then mixing the activator with the light fraction according to a predetermined mass ratio and stirring for a predetermined time to obtain a mixed homogeneous liquid of the light fraction and the activator, subjecting the mixed homogeneous liquid to two-stage heating and one-step carbonization and activation under a protection of an inert gas, and cooling to room temperature to obtain an impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon; S2, grinding the impurity-containing bio-oil light fraction-based bread-shaped porous activated carbon obtained in step S1 and sieving for the first time, washing and stirring with a hydrochloric acid solution, then repeatedly washing and suction filtering with deionized water until a filtrate is neutral, so as to remove activator reaction products and impurities in the solid product, drying, grinding again and sieving for the second time, and obtaining the bio-oil light fraction-based bread-shaped porous activated carbon
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE EMBODIMENTS
[0061] The following detailed description of the embodiments is exemplary in order to further explain the present application. Generally, all technical and scientific terms used herein have the same meanings as those commonly understood by ordinary people in the technical field to which this application belongs.
[0062] It should be noted that the terminology used in the following detailed description is only for describing the detailed description, and is not intended to limit the exemplary embodiments according to the present application. In the following detailed description, unless the context clearly indicates otherwise, the singular form and the plural form were the same. It should be noted that “comprising” used in this specification indicates the presence of features, steps, operations, components, devices and/or combinations thereof.
[0063] The key idea of the present application lies in the present application of a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon. A small amount of an activator is directly mixed with a light fraction of bio-oil molecular distillation to obtain a uniform liquid mixture. The bread-shaped porous activated carbon with the characteristics of a uniform pore distribution, a large specific surface area and no ash is obtained by one-step activation method in two temperature stages, which reduces the usage amount of the activator, reduces the corrosion to the equipment and further improves the electrochemical performance of electrode materials of supercapacitors.
[0064] As described in the technical background, the existing chemical activation methods for preparing activated carbon mainly adopt one-step activation or two-step activation, and at the same time, the activator is mixed with a carbon precursor in a large mass ratio (activator: biomass or activator: pre-carbide). Commonly used mixing methods include grinding mixing, ultrasonic mixing, etc., which leads to the fact that the activator and the activation precursor can not be uniformly mixed, resulting in poor uniformity of the mixture. Secondly, a large number of activators need to be used, thus increasing the cost and causing environmental pollution, and the pore distribution of the obtained activated carbon is uneven. Because of the different kinds of biomass, it is difficult to unify the preparation process. in order to solve the above shortcomings, the present application provides a bio-oil light fraction-based bread-shaped porous activated carbon as well as a method for preparing the same and use thereof.
[0065] The systematic research and verification of the present application shows that the liquid bio-oil light fraction is mixed with a very small amount of an activator, and a uniform liquid mixture can be obtained after a certain period of magnetic stirring. This process can obviously reduce the amount of activator used and the corrosion to the equipment. Moreover, after one-step carbonization and activation at two temperature stages, the activated carbon with large specific surface area and uniform pore distribution can be obtained, and the pore size is mainly concentrated in the micropore size range, which provides a lot of space for the attachment of electrolyte ions. At the same time, the ash-free feature of activated carbon product can further improve the electrochemical performance of supercapacitors.
[0066] The present application provides a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0067] Step 1, preparation of raw materials: lignocellulosic biomass such as husk, sawdust, straw, bamboo, etc. is selected for rapid pyrolysis, with a final pyrolysis temperature of 350-800° C. and a heating rate ≥100° C./min., to obtain biomass fast pyrolyzed bio-oil; further, the pyrolyzed bio-oil is subjected to molecular distillation, the molecular distillation pressure is usually in the range of 10-3000 Pa, the molecular distillation temperature is from normal temperature to 200° C., and the working pressure of the short-range distiller is 0.001-1 mbar, so as to obtain different kinds of bio-oil fractions, and the light fraction is used as the precursor for the preparation of activated carbon,
[0068] Step 2, preparation of an activator: a solid water-soluble active metal alkali such as potassium hydroxide and sodium hydroxide is selected; a solid water-soluble active metal salt such as potassium carbonate, sodium carbonate, potassium bicarbonate and sodium bicarbonate is prepared according to the mass ratio (activator: light fraction=1:22-3).
[0069] Step 3, mixing raw materials and activators: the activators in step 2 is added into the light fraction in step 1, the container is quickly sealed, the mixture is stirred with a magnetic stirrer for 0.5-2 hours, the water-soluble activator is fully dissolved in the water of the light fraction, and uniformly mixed to obtain a uniform liquid mixture.
[0070] Step 4, first-stage activation: the liquid mixture in step 3 is put in a nickel boat with an appropriate size in a horizontal tube furnace, and inert gases such as nitrogen, argon and helium are introduced into the tube furnace at a gas flow rate of 100-300 mL/min, a heating rate of 2-10° C./min, and a final heating temperature of 300-500° C. for 0.5-3 hours.
[0071] Step 5, second-stage activation: when the heating in step 4 is finished, the container is continually heated to a final temperature of 700-900° C. at a heating rate of 2-10° C./miry for 1-3 hours, and then cooled to room temperature to obtain the bread-shaped porous activated carbon.
[0072] Step 6, grinding and washing: after fully grinding the obtained bread-shaped porous activated carbon with a ball mill, it is sieved with a sieve of 100-200 meshes, the sieved powder is washed with a 0.5-2 M hydrochloric acid solution, magnetically stirred for 3-6 hours, repeatedly washed and filtered with suction with deionized water until the filtrate is neutral, so as to remove impurities such as reactant of activator in the activated carbon.
[0073] Step 7, drying and grinding: the product obtained in step 6 is dried in a ventilated drying oven for 10-12 hours, ground with a ball mill, and sieved with a 200-300 mesh sieve, finally obtaining the activated carbon which can be used as the energy storage active material of the electrode of the super capacitor. The light fraction used in the present application is brown-black, and the light fraction: 1) contains 15-50% water; 2) contains small molecular compounds including acids (20-30%), ketones (5-15%), aldehydes (5-10%) and. monophenols (10-20%); 3) does not contain macromolecular compounds with a long carbon chain and a large molecular weight, such as pyrolytic lignin, aromatic polymer, anthracene, phenolic polymer and sugar; 4) does not contain ash.
[0074] Preferably, the light fraction of molecular distillation of bio-oil comes from walnut shell, poplar sawdust, corn straw and rice husk.
[0075] Preferably, the water content of the bio-oil molecular distillation light fraction is 20%-40%. Preferably, the light fraction of bio-oil molecular distillation contains small molecular compounds such as acids (20-25%), ketones (8-10%), aldehydes (5-8%) and monophenols (12-15%), which is more conducive to the preparation of a bio-oil molecular distillation light fraction-based bread-shaped. porous activated carbon.
[0076] Preferably, the activator is potassium hydroxide or potassium bicarbonate. Preferably, the mass ratio of the bio-oil molecular distillation light fraction to the activator is 9-11:1, Preferably, the inert gas is nitrogen. Preferably, the specific steps of two-stage heating activation were as follows: the first temperature stage is 400° C., the heat holding time is 2 h, and the heating rate is 2° C./min; the second temperature stage is 800° C., the heat holding time is 2-3 h, and the heating rate is 2° C./min.
[0077] Salts, such as sodium salt and potassium salt, in the washing liquid generated in the preparation process of the present application can be recycled.
[0078] In a typical embodiment of the present application, the bio-oil molecular distillation light fraction-based bread-shaped porous activated carbon prepared by the above method steps is provided.
[0079] In a typical embodiment of the present application, use of the bio-oil light fraction-based bread-shaped porous activated carbon in supercapacitors is provided.
[0080] In a typical embodiment of the present application, an electrode material of a super capacitor is provided, which is prepared by using the bio-oil light fraction-based bread-shaped porous activated carbon.
[0081] In the embodiment of the present application, the bio-oil light fraction-based.
[0082] bread-shaped porous activated carbon has a three-dimensional porous structure, with a specific surface area of 1000-3000 m.sup.2/g, a pore volume of 0.5-1.5 cm.sup.3/g and an average pore diameter of 1.8-2.6 nm. In the three-electrode test system, the mass-specific capacitance of the material with 6 M KOH and 1 M H.sub.2SO.sub.4 as an aqueous electrolyte is 80-770 F/g, and that of the material with 6 M KOH as an electrolyte in a button two-electrode supercapacitor of CR2025 is 80-240 F/g. In the three-electrode 6 M KOH aqueous electrolyte system, the mass-specific capacitance decays slowly with the increase of current intensity. The specific capacitance at 1 A/g, is 192 F/g, and the specific capacitance at 100 A/g is 148 F/g. After the current density increases 100 times, the specific capacitance attenuation of electrode materials is less than 25%.
[0083] The present application provides a bio-oil light fraction-based bread-shaped porous activated carbon for molecular distillation. Its specific surface area, pore size distribution, pore volume and average pore size can be adjusted and controlled by changing the proportion of the activator, the activation temperature and the activation time, and it is used as an electrode active material of supercapacitors.
[0084] In the embodiment of the present application, the representation and performance test method of a bio-oil light fraction-based bread-shaped porous activated carbon electrode material for supercapacitors is as follows:
[0085] Representation test 1: Measurements of the specific surface area, the pore volume, the pore size distribution, the specific surface area distribution and average pore size: the adsorption-desorption isotherm of nitrogen by the activated carbon in liquid nitrogen was measured, and the specific surface area and average pore size were obtained according to a BET model; the pore volume was obtained according to the total pore volume of the single-point adsorption pore; the pore size distribution and specific surface area distribution were obtained according to a DFT model.
[0086] Representation test 2: SEM representation test: by a SL 8010 cold field emission scanning electron microscope made by HITACHI, Japan, obtained by treatment after gold spraying.
[0087] Representation test 3: X-ray photoelectron spectroscopy test: by an ESCALAB X-ray photoelectron spectrometer of VG Company in UK, with a range of 0-1100 eV
[0088] Representation test 4: Raman spectrum test: by a 532 nm laser confocal Raman spectrometer of LabRAM HR Evolution of French Horiba Jobin Yvon Company, with a range of 400-2450 cm.sup.−1.
[0089] Representation test 5: Specific capacitance test: by a CH.sup.-1660E electrochemical workstation of China Chenhua Company.
EXAMPLE 1
[0090] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0091] Step 1, preparation of raw materials: walnut shells were selected as biomass raw materials, and bin-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0092] Step 2, preparation of an activator: K.sub.2CO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:9).
[0093] Step 3, mixing raw materials and the activator: the activators in step 2 was slowly added into the light fraction in step 1, the container was sealed, and the mixture was stirred. for 1 hour with a magnetic stirrer to fully mix the activator with the light fraction to obtain a liquid homogeneous mixture.
[0094] Step 4, first-stage activation: the liquid mixture in step 3 was put in a nickel boat, and the nickel boat was placed in a horizontal tube furnace, which was filled with inert gases such as nitrogen and argon, with a gas flow rate of 300 mL/min, a heating rate of 2° C./min, a final heating temperature of 400° C. and a heat holding time of 3 hours.
[0095] Step 5, second-stage activation: after the heating stage in step 4, the furnace was continually heated to 800° C. at a heating rate of 2° C/min for 3 hours, and then cooled to room temperature to obtain a bread-shaped porous activated carbon.
[0096] Step 6, grinding and washing: the obtained activated carbon was fully ground with a ball mill, and after sieving with a 200-mesh sieve, the obtained powdery solid was washed with a 1 M hydrochloric acid solution, magnetically stirred for 6 hours, then repeatedly washed and filtered with suction with deionized water until the filtrate was neutral, and the remaining activator and generated inorganic salts in the activated carbon were removed.
[0097] Step 7, drying and grinding: the product obtained in step 6 was dried in a ventilated drying oven for 12 hours, and then ground with a ball mill and sieved with a 220-mesh sieve to finally obtain the activated carbon which can be used as the energy storage active material of supercapacitor electrodes.
[0098] Step 8, 0.08 g of the bio-oil light fraction-based bread-shaped porous activated carbon obtained in step 7 was taken, and the test material, conductive carbon black and a binder were added into the activated carbon in the ratio of 8:1:1, and then isopropanol was added, fully ground and rolled into a film. Then the film was dried at 110° C. for 12 hours in a ventilated drying oven, cut into square carbon films of 1 cm×1 cm, and the cut carbon film was pressed onto 1 cm×2 cm foam nickel (a current collector) under a pressure of 10 MPa.
[0099] Step 9, the carbon film cut out in step 8 was pressed on 1 cm×2 cm conductive carbon paper (a current collector).
[0100] Step 10, the carbon film prepared in step 8 was cut into a circular carbon film with a diameter of 1.5 cm, the carbon film was pressed on foamed nickel of the same size, two electrode pieces with a similar mass were selected as symmetrical electrodes (two-electrode system), and were separated with a PTFE separator, and assembled in a button capacitor of CR2025, wherein 6 M KOH as was used as an electrolyte.
[0101] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 1 has a specific surface area of 1326 m.sup.2/g, a pore volume of 0.623 m.sup.3/g, and an the average pore diameter of 1.88 nm; the pore diameter distribution was shown in
[0102] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system in, and the specific capacitance was 234 F/g at a current density of 0.1 A/g, as shown in
EXAMPLE 2
[0103] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0104] Step 1, preparation of raw materials: walnut shells were selected as biomass raw materials, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and a short-range distiller world rig pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0105] Step 2, preparation of an activator: K.sub.2CO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:9).
[0106] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 1; Step 5, the same as step 5 of Example 1, except that the final heating temperature was changed to 700° C.; Steps 6-10 were the same as those of Example 1.
[0107] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 2 has a specific surface area of 1,730 m.sup.2/g, a pore volume of 0.830 m.sup.2/g, and an average pore diameter of 1.92 nm; the pore diameter distribution was shown in
[0108] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 193 F/g at t a current density of 0.1 A/g, 170 F/g at t a current density of 1 A/g and 122 F/g at a current density of 100 A/g; electrodes made of conductive carbon paper as current collectors were used in 1 M H.sub.2SO.sub.4 electrolyte to form a three-electrode system; the specific capacitance was 560 F/g at t a current density of 0.1 A/g, 335 F/g at t a current density of 1 A/g and 110 F/g at a current density of 100 A/g; in the two-electrode system, the specific capacitance was 171 F/g at a current density of 0.1 A/g, 160 F/ at a current density of 1 A/g and 152 F/g at a current density of 50 A/g.
EXAMPLE 3
[0109] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0110] Step 1, preparation of raw materials: walnut shells were selected as biomass raw materials, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0111] Step 2, preparation of an activator: K.sub.2CO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:11).
[0112] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 1, except that the heating rate was changed to 5° C./min and the temperature was kept for 2 hours; Step 5, the same as step 5 of Example 1, except that the heating rate was changed to 5° C./min, the final heating temperature to 900° C. and the heat holding time to 2 hours; Step 6,the same as step 6 of Example 1; Step 7, the same as step 7 of Example 1, in which a sieve with a mesh size of 300 mesh was selected; Step 8, the same as step 8 of Example 1.
[0113] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 3 has a specific surface area of 1830 m.sup.2/g, a pore volume of 1.12 m.sup.3/g, and an average pore diameter of 2.45 nm.
[0114] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 160 F/g at a current density of 0.1 A/g, 154 F/g at a current density of 1 A/g, 129 F/g at a current density of 50 A/g and 124 F/g at a current density of 100 A/g.
EXAMPLE 4
[0115] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0116] Step 1, preparation of raw materials: rice hulls were selected as biomass raw materials, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1800 Pa/60° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0117] Step 2, preparation of an activator: K.sub.2CO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:10).
[0118] Step 3, the same as step 3 of Example 1; Step 4: the same as step 4 of Example 3, except that the heating rate was changed to 10° C./min and the final heating temperature to 300° C.; Step 5, the same as step 5 of Example 3, except that the heating rate was changed to 10° C./min, the final heating temperature to 800° C. and the heat holding time to 2 hours; Steps 6 to 9 were the same as those of Example 1.
[0119] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 4 has a specific surface area of 2044 m.sup.2/g, a pore volume of 1.088 m.sup.3/g, and an average pore diameter of 2.13 nm, and the nitrogen adsorption-desorption curve was shown in
[0120] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in 6 M KOH electrolyte to assemble a three-electrode system, with a specific capacitance of 191 F/g at a current density of 0.1 A/g, 173 F/g at a current density of 1 A/g and 134 F/g at a current density of 50 A/g; electrodes made of conductive carbon paper as current collectors were used in a 1 M H.sub.2SO.sub.4 electrolyte to form a three-electrode system; the specific capacitance was 644 F/g at a current density of 0.1 A/g, 394 F/g at a current density of 1 A/g and 118 F/g at current density of 100 A/g.
EXAMPLE 5
[0121] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0122] Step 1, preparation of raw materials: corn stalks were selected as biomass raw materials, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/50° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0123] Step 2, preparation of an activator: K.sub.2CO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:15).
[0124] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 4, except that the final heating temperature was changed to 500° C. and the temperature was kept for 3 hours; Step 5, the same as step 5 of Example 4, except that the final heating temperature was changed to 900° C. and the temperature was kept for 3 hours; Steps 6-10 were the same as those of Example 1.
[0125] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 5 had a specific surface area of 1761 m.sup.2/g, a pore volume of 0.850 m.sup.3/g, and an average pore diameter of 1.93 nm.
[0126] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system, with a specific capacitance of 190 F/g at a current density of 0.1 A/g, 167 F/g at a current density of A/g and 118 F/g at a current density of 50 A/g; electrodes made of conductive carbon paper as current collectors were used in 1 a M H.sub.2SO.sub.4 electrolyte to form a three-electrode system; the specific capacitance was 552 F/g at a current density of 0.1 A/g, 327 F/g at a current density of 1 A/g and 109 F/g at a current density of 100 A/g; in the two-electrode system, the specific capacitance was 168 F/g at a current density of 0.1 A/g, 157 F/g at a current density of 1 A/g and 140 F/g at a current density of 50 A/g.
EXAMPLE 6
[0127] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0128] Step 1, preparation of raw materials: scraps of willow were selected as biomass raw materials, and bio-oil was Obtained after rapid pyrolysis at 450° C.; under the molecular distillation conditions of 1700 Pa/70° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0129] Step 2, preparation of an activator: KHCO.sub.3 was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:3).
[0130] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 3, except that the heat holding time was 0.5 hours; Step 5, the same as step 5 of Example 3, except that the final heating temperature was changed to 800° C. and the temperature was kept for 3 hours; Steps 6-10 were the same as those of Example 1.
[0131] Implementation effect 1: bio-oil light fraction-based bread-shaped porous activated. carbon in Example 6 has a specific surface area of 1950 m.sup.2/g, a pore volume of 1.126 m.sup.3/g and an average pore diameter of 2.31 nm.
[0132] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system, with a specific capacitance of 210 F/g at a current density of 0.1 A/g, 190 F/g at current density of 1 A/g and 163 F/g at a current density of 50 A/g; electrodes made of conductive carbon paper as current collectors were used in a 1 M H.sub.2SO.sub.4 electrolyte to form a three-electrode system; the specific capacitance was 530 F/g at a current density of 0.1 A/g, 360 F/g at a current density of 1 A/g and 134 F/g at a current density of 100 A/g; in the two-electrode system, the specific capacitance was 172 F/g at a current density of 0.1 A/g, 160 F/g at a current density of 1 A/g and 145 F/g at a current density of 50 A/g.
EXAMPLE 7
[0133] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0134] Step 1, preparation of raw materials: scraps of willow were selected as biomass raw materials, and bio-oil was obtained after rapid pyrolysis at 450° C.; under the molecular distillation conditions of 3000 Pa/70° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0135] Step 2, preparation of an activator: KOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:22).
[0136] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 1, except that the heat holding time was changed to 1 hour; Step 5, the same as step 5 of Example 1, except that the heat holding time was changed to 2 hours; Steps 6-8 were the same as those of Example 1.
[0137] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 7 had a specific surface area of 1736 m.sup.2/g, a pore volume of 1.085 m.sup.3/g, and an average pore diameter of 2.50 nm.
[0138] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 191 F/g at a current density of 0.1.A/g, 164 F/g at a current density of 1 A/g and 117 F/g at a current density of 50 A/g.
EXAMPLE 8
[0139] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0140] Step 1, preparation of raw materials: bamboo was selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 500° C.; under the molecular distillation conditions of 1700 Pa/60° C. and a short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light, fraction, which was used as a raw material for a carbon precursor.
[0141] Step 2, preparation of activator: NaOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:3).
[0142] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 1, except that the final heating temperature was 500° C. and the heat holding time was 2 hours; Step 5, the same as step 5 of Example 1, except that the final heating temperature was changed to 900° C.; Step 6, the same as step 6 of Example 1; Step 7, the same as step 7 of Example 1, in which a sieve with a mesh size of 400 mesh was selected; Step 8, the same as step 8 of Example 1.
[0143] Implementation effect 1: bio-oil light fraction-based bread-shaped porous activated carbon in Example 8 had a specific surface area of 1240 m.sup.2/g, a pore volume of 0.769 m.sup.3/g, and an average pore diameter of 2.48 nm.
[0144] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 156 F/g at a current density of 0.1 A/g, 124 F/g at a current density of 1 A/g and 101 F/g at a current density of 50 A/g.
EXAMPLE 9
[0145] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0146] Step 1, preparation of raw materials: bamboo was selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 450° C.; under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0147] Step 2, preparation of activator: K.sub.2CO.sub.3 was selected as activator, and activator was prepared according to the mass ratio (activator: light fraction=1:3).
[0148] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 8; Step 5, the same as step 5 of Example 8, except that the final heating temperature was changed to 800° C. and the temperature was kept for 2 hours; Step 6: the same as step 6 of Example 1; Step 7: the same as step 7 of Example 1, in which a sieve with a mesh size of 500 mesh was selected; Step 8, the same as step 8 of Example 1.
[0149] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 9 had a specific surface area of 2030 m.sup.2/g, a pore volume of 1.03 m.sup.3/g and an average pore diameter of 2.03 nm.
[0150] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 215 Fig at a current density of 0.1 A/g, 194 F/g at a current density of 1 A/g and 145 F/g at a current density of 50 F/g.
EXAMPLE 10
[0151] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0152] Step 1, preparation of raw materials: bamboo was selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 450° C.; under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.01 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0153] Step 2, preparation of an activator: KOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:3.7).
[0154] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 2, except that the heating rate was 5° C./min and the heat holding time was 2 hours; Step 5, the same as step 5 of Example 2, except that the heating rate was 5° C/min and the final heating temperature was 800° C.; Steps 6-8 were the same as those of Example 1.
[0155] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 10 had a specific surface area of 2103 m.sup.2/g, a pore volume of 1.19 m.sup.3/g, and an average pore diameter of 2.27 nm.
[0156] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 212 F/g at a current density of 0.1 A/g, 193 F/g at a current density of 1 A/g and 144 F/g at a current density of 50 A/g.
EXAMPLE 11
[0157] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0158] Step 1, preparation of raw materials: bamboo was selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 450° C. under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.01 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0159] Step 2, preparation of an activator: KOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:3.7).
[0160] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 3, except that the heating rate was 8° C/min; Step 5, the same as step 5 in Example 3, except that the heating rate was 8° C./min; Steps 6-8 were the same as those of Example 1.
[0161] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 11 had a specific surface area of 1706 m.sup.2/g, a pore volume of 0.943 m.sup.3/g, and an average pore diameter of 2.21 nm.
[0162] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 176 F/g at a current density of 0.1 A/g, 154 F/g at a current density of 1 A/g and 121 F/g at a current density of 50 A/g.
EXAMPLE 12
[0163] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0164] 1. Preparation of raw materials: walnut shells were selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0165] Step 2, preparation of an activator: KOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:5.5).
[0166] Step 3, the same as step 3 of Example 1; Step 4, the same as step 4 of Example 1, except that the heat holding time was 2 hours; Step 5, the same as step 5 of Example 3, except that the heat holding time was 2 hours; Steps 6-8 were the same as those of Example 1.
[0167] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 12 had a specific surface area of 1905 m.sup.2/g, a pore volume of 1.062 m.sup.3/g, and an average pore diameter of 2.23 nm.
[0168] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 183 F/g at a current density of 0.1 A/g, 168 F/g at a current density of 1 A/g and 129 F/g at a current density of 50 A/g.
EXAMPLE 13
[0169] The present application relates to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, which includes the following steps:
[0170] 1. Preparation of raw materials: walnut shells were selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0171] Step 2, preparation of an activator: KOH was selected as an activator, and activator was prepared according to the mass ratio (activator: light fraction=1:11).
[0172] Step 3, the same as step 3 of Example 1. Step 4: the same as step 4 of Example 1, except that the final heating temperature was 500° C.; Step 5: the same as step 5 of Example 3, except that the final heating temperature was 900° C.; Steps 6-8 were the same as those of Example 1.
[0173] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 13h had a specific surface area of 1874 m.sup.2/g, a pore volume of 0.900 m.sup.3/g, and an average pore diameter was 1.92 nm.
[0174] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 169 F/g at a current density of 0.1 A/g, 141 F/g at a current density of 1 A/g and 107 F/g at a current density of 50 A/g.
EXAMPLE 14
[0175] According to a method for preparing a bio-oil light fraction-based bread-shaped porous activated carbon, in this example, the heating method was different from that of Examples 1-13. This example adopts the one-step carbonization activation method of a single temperature stage to compare and illustrate that the bio-oil light fraction-based bread-shaped porous activated carbon prepared by the one-step carbonization activation method of two temperature stages has better physical and chemical characteristics.
[0176] The method includes the following steps:
[0177] Step 1, preparation of raw materials: walnut shells were selected as a biomass raw material, and bio-oil was obtained after rapid pyrolysis at 550° C.; under the molecular distillation conditions of 1500 Pa/60° C. and short-range distiller working pressure of 0.1 mbar, the bio-oil molecules were distilled into a light fraction, which was used as a raw material for a carbon precursor.
[0178] Step 2, preparation of an activator: KOH was selected as an activator, and the activator was prepared according to the mass ratio (activator: light fraction=1:11).
[0179] Step 3, the same as step 3 of Example 1.
[0180] Step 4, the liquid mixture in step 3 was put in a nickel boat into a horizontal tube furnace, and inert gases such as nitrogen and argon were introduced into the tube furnace at a gas flow rate of 300 mL/min, the temperature was directly increased to a final heating temperature of 800° C. with heating rate was 2° C./min, and a heat holding time of 2 hours, and then the mixture was naturally cooled to room temperature to obtain a solid product.
[0181] Step 5, the same as step 6 of Example 1; Step 6: the same as step 7 of Example 1, in which a sieve with a mesh size of 300 mesh was selected; Step 7, the same as step 8 of Example 1.
[0182] Implementation effect 1: the bio-oil light fraction-based bread-shaped porous activated carbon in Example 14 had a specific surface area of 1330 m.sup.2/g, a pore volume of 0.85 m.sup.3/g, and an average pore diameter of 2.56 nm.
[0183] Implementation effect 2: the electrode with rectangular foam nickel as a current collector was used in a 6 M KOH electrolyte to assemble a three-electrode system; the specific capacitance was 123 F/g at a current density of 0.1 F/g, 98 F/g at a current density of 1 A/g and 74 F/g at a current density of 50 A/g.
[0184] The above examples were the preferred embodiments of the present application, but the embodiments of the present application were not limited by the above examples. Any other changes, modifications, substitutions, combinations and simplifications that do not violate the spirit and principles of the present application should be equivalent replacement methods, which were included in the scope of protection of the present application.