Disclosure of Invention
The invention mainly aims to provide a preparation method of provider bamboo activated carbon and the provider bamboo activated carbon, and solves the technical problem that bamboo activated carbon in the prior art cannot give consideration to adsorption performance, form and strength.
In order to achieve the above object, according to a first aspect of the present invention, there is provided a method for preparing square bamboo activated carbon, the technical scheme being as follows:
the preparation method of square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections;
(2) Putting the short section into a solvent and boiling;
(3) Putting the short section into steam for steaming;
(4) Drying the short section and then carbonizing;
(5) Dipping the short section into a reinforcing base;
(6) And drying the short section and activating to obtain the square bamboo activated carbon.
As a further improvement of the first aspect of the invention, the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2-3 cm.
As a further development of the first aspect of the invention, the solvent is water or lye; boiling for 1-3 h.
As a further improvement of the first aspect of the present invention, the solvent is a sodium hydroxide solution with a mass fraction of 3 to 10%.
As a further development of the first aspect of the invention, the steam is water vapor; steaming for 1-3 h.
As a further improvement of the first aspect of the invention, the carbonization temperature is 400-600 ℃, and the carbonization time is 1-2 h.
As a further development of the first aspect of the invention, the reinforcing group is a silica sol.
As a further improvement of the first aspect of the invention, the silica sol with the mass fraction of 15-20% is dipped in a reaction kettle at the dipping temperature of 180-220 ℃ for 5-7 h, or is dipped at normal temperature and normal pressure for 5-7 h, and is kept stand for 5-7 h after dipping.
As a further improvement of the first aspect of the invention, the activation temperature is 850-950 ℃, the activation time is 3-5 h, and the activating agent is water vapor.
In order to achieve the above object, according to a second aspect of the present invention, there is also provided bamboo activated carbon, the technical solution is as follows:
activated carbon prepared by the method of the first aspect.
The preparation method of the square bamboo activated carbon and the square bamboo activated carbon have the following advantages:
the hollow bamboo tube structure naturally formed in the square bamboo is used as a structural framework foundation of the hollow activated carbon, powder making and forming are not needed, and the preparation process and the raw material cost are obviously shortened.
The boiling can improve vertical moisture permeability, increase the inside space of bamboo timber, reduce the degree of difficulty of moisture migration, can slowly deviate from the inside lignin of bamboo timber simultaneously. Because the lignin in the bamboo wood can be dissolved in the alkali liquor, when the sodium hydroxide solution is selected and boiled, the lignin can be quickly removed, and the cracking phenomenon caused by the structural damage caused by the high-temperature quick decomposition of the lignin in the square bamboo in the subsequent heat treatment process is reduced.
The steam can increase the internal energy of water molecules of the bamboo, the activity is enhanced, and the connection force among the structural components of the bamboo is reduced, so that the bamboo is softened. The bamboo softening reduces the deformation resistance of the bamboo, reduces the drying shrinkage stress, reduces the possibility of cracking, and ensures that the dehydrated structure tends to be densified.
During the carbonization process, the fiber components in the square bamboo can be removed preliminarily, and macropores in the active carbon are produced preliminarily.
The reinforcing base can be sufficiently dispersed in the carbonized square bamboo structure by impregnation. The preferred impregnation process is to complete the impregnation in a reaction vessel, so that the impregnation efficiency can be improved by pressure impregnation. The silica sol is a dispersion of nano-scale silica particles in water or solvent, and the silica sol is impregnated into the carbonized square bamboo structure to occupy the volatilization and precipitation positions in the square bamboo structure, and can form Si0 with high strength in the square bamboo activated carbon after heat treatment 2 The monomer structure remolds the skeleton texture, strengthens the intensity of bamboo activated carbon.
In conclusion, the preparation method of the square bamboo activated carbon with the hollow structure, which does not need a forming process, is simple in process, gets rid of the traditional activated carbon powder forming process, does not need to add bonding agents and other kneading forming auxiliary materials, remarkably reduces the production cost of the hollow activated carbon, and is more environment-friendly. The verification proves that the square bamboo activated carbon prepared by the preparation method disclosed by the invention is extremely low in cracking rate, the original cylindrical shape of the square bamboo raw bamboo is still well maintained, the outer diameter of the square bamboo activated carbon is 15-20 mm, the wall thickness is 1-3 mm, the square bamboo activated carbon is easy to transport and use, and has higher strength and extremely high iodine value, so that the square bamboo activated carbon can obtain better adsorption performance and longer service cycle when in use, can be applied to a wider field, and improves the economic value of the square bamboo.
The invention is further described with reference to the following figures and detailed description. Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
The invention will be described more fully hereinafter with reference to the accompanying drawings. Those skilled in the art will be able to implement the invention based on these teachings. Before describing the present invention in detail with reference to the accompanying drawings, it is to be noted that:
the technical solutions and features provided in the present invention in the respective sections including the following description may be combined with each other without conflict.
Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.
With respect to terms and units in the present invention. The terms "comprising," "having," and any variations thereof in the description and claims of this invention and the related sections are intended to cover non-exclusive inclusions.
The specific implementation mode of the preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2-3 cm.
(2) Putting the short section into a solvent for boiling: the solvent is water or sodium hydroxide solution with the mass fraction of 3-10%, and the boiling is carried out for 1-3 h.
(3) And putting the short section into steam to steam for 1-3 h.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 400-600 ℃, and the carbonization time is 1-2 h.
(5) Dipping the pup joint in a reinforcing base: the reinforcing base is 15-20% silica sol, and is soaked in a reaction kettle at 180-220 ℃ for 5-7 h, or is soaked at normal temperature and pressure for 5-7 h, and is kept stand for 5-7 h after being soaked.
(6) Drying and activating the short section to obtain square bamboo activated carbon; the activation temperature is 850-950 ℃, the activation time is 3-5 h, and the activating agent is water vapor.
The square bamboo activated carbon is prepared by the preparation method.
The advantageous effects of the present invention are illustrated below by specific examples.
Example 1
The preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2cm.
(2) Putting the short section into a solvent for boiling: the solvent is water and is boiled for 2 hours.
(3) And putting the short section into steam to be steamed for 1 hour.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 600 ℃, and the carbonization time is 1h.
(5) Dipping the pup joint in a reinforcing base: the reinforcing base is 15% silica sol by mass, the impregnation is carried out at normal temperature and normal pressure for 6 hours, and the reinforcing base is taken out and kept stand for 6 hours after the impregnation.
(6) Drying the short sections and then activating to obtain square bamboo activated carbon; the activation temperature is 900 ℃, the activation time is 3h, and the activating agent is water vapor.
Example 2
The preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2cm.
(2) Putting the short section into a solvent for boiling: the solvent is water and is boiled for 2 hours.
(3) And putting the short section into steam to be steamed for 1 hour.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 600 ℃, and the carbonization time is 1h.
(5) Dipping the pup joint in a reinforcing base: the reinforcing base is silica sol with the mass fraction of 20%, the impregnation is carried out at normal temperature and normal pressure for 6 hours, and the reinforcing base is taken out and stands for 6 hours after the impregnation.
(6) Drying the short sections and then activating to obtain square bamboo activated carbon; the activation temperature is 900 ℃, the activation time is 3h, and the activating agent is water vapor.
Example 3
The preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2cm.
(2) Putting the short section into a solvent for boiling: the solvent is water and is boiled for 2 hours.
(3) And putting the short section into steam to be steamed for 1 hour.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 600 ℃, and the carbonization time is 1h.
(5) Dipping the pup joint in a reinforcing matrix: the reinforcing base is 15% silica sol by mass, and is soaked in a reaction kettle at the soaking temperature of 200 ℃ for 6 hours.
(6) Drying and activating the short section to obtain square bamboo activated carbon; the activation temperature is 900 ℃, the activation time is 3h, and the activating agent is water vapor.
Example 4
The preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2cm.
(2) Putting the short section into a solvent for boiling: the solvent is sodium hydroxide solution with the mass fraction of 8%, and the solution is boiled for 2 hours.
(3) And putting the short section into steam to be steamed for 1 hour.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 600 ℃, and the carbonization time is 1h.
(5) Dipping the pup joint in a reinforcing base: the reinforcing base is 15% silica sol by mass, and is impregnated at normal temperature and normal pressure for 6 hours, and the reinforcing base is kept stand for 6 hours after impregnation.
(6) Drying the short sections and then activating to obtain square bamboo activated carbon; the activation temperature is 900 ℃, the activation time is 3h, and the activating agent is water vapor.
Example 5
The preparation method of the square bamboo activated carbon comprises the following steps:
(1) Cutting the square bamboo into short sections: the outer diameter of the square bamboo is 2-3 cm, the wall thickness is 3-4 mm, and the length of the short section is 2cm.
(2) Putting the short section into a solvent for boiling: the solvent is 8 percent sodium hydroxide solution by mass percent and is boiled for 2 hours.
(3) And putting the short section into steam to be steamed for 1 hour.
(4) And (3) drying the short section and then carbonizing: the carbonization temperature is 600 ℃, and the carbonization time is 1h.
(5) Dipping the pup joint in a reinforcing base: the reinforcing base is 15% silica sol by mass, and is soaked in a reaction kettle at the soaking temperature of 200 ℃ for 6 hours.
(6) Drying the short sections and then activating to obtain square bamboo activated carbon; the activation temperature is 900 ℃, the activation time is 3h, and the activating agent is water vapor.
Comparative example
Directly carbonizing and activating the cut raw bamboo of the square bamboo: the carbonization temperature is 600 ℃, the carbonization time is 1h, the activation temperature is 900 ℃, and the activation time is 3h.
Table 1 shows iodine value, compressive strength and cracking rate of square bamboo activated carbon prepared in examples 1 to 5 and comparative example.
TABLE 1
As can be seen from Table 1, the iodine values of the square bamboo activated carbon of examples 1 to 5 were all 800mg/g or more, and had a good compressive strength. Compared with a comparative example, the iodine value and the compressive strength are obviously improved and the cracking rate is obviously reduced after the digestion and the impregnation treatment.
The iodine value is tested by adopting the 'GB/T14296.8-2015 determination of iodine adsorption value of wood activated carbon experimental method'.
The compressive strength is tested by adopting a GB/T1964-1996 porous ceramic compressive strength test method.
The cracking rate refers to the proportion of the short sections with cracks or fractures on the surface after activation to the total number of the short sections.
It was verified that the square bamboo activated carbon of examples 1 to 5 was in the natural shape of the original bamboo, and had good appearance quality and less cracking and deformation.
FIG. 1 is a scanning electron microscope photomicrograph of square bamboo activated carbon of example 2. FIG. 2 is a photograph taken by a high scanning electron microscope of square bamboo activated carbon of example 2. As can be seen from FIGS. 1-2, the square bamboo activated carbon has a large number of macroporous structures with a size of 1-20 μm, and the pore structures are uniformly distributed.
FIG. 3 is a graph showing nitrogen adsorption and desorption of square bamboo activated carbon in example 2. Figure 4 is a pore structure distribution diagram of square bamboo activated carbon of example 2. As can be seen from FIG. 3, the square bamboo activated carbon has I-shaped isothermal adsorption and desorption curves, which reflect the microporous adsorbentThe micropore filling phenomenon proves that the square bamboo activated carbon is a micropore material. Meanwhile, the maximum ratio of micropores with the diameter of 0.563nm can be verified according to a pore structure distribution diagram. According to the pore structure analysis, the average pore diameter of the square bamboo activated carbon is 1.75nm, and the total pore volume is 0.3764cm 3 Per g, specific surface area of 859.087m 2 /g。
The contents of the present invention have been explained above. Those skilled in the art will be able to implement the invention based on these teachings. All other embodiments, which can be derived by a person skilled in the art from the above description without inventive step, shall fall within the scope of protection of the present invention.