Paper biomass charcoal as well as preparation method and application thereof

Abstract

The technical scheme of the invention provides paper biomass charcoal as well as a preparation method and application thereof, and belongs to the technical field of resource reutilization. The preparation method of the paper biomass charcoal provided by the invention comprises the following steps: crushing paper wastes, and soaking the crushed paper wastes in water to obtain paper pulp; stirring is performed during soaking; mixing the obtained paper pulp with an oxidizing agent for oxidation reaction to obtain oxidized paper pulp; the obtained oxidized paper pulp is sequentially subjected to freeze thawing treatment and carbonization treatment, and the paper biomass charcoal is obtained. The preparation method is easy to operate, environmental pollution generated in the process of regenerating paper products from paper waste is reduced, meanwhile, excessive development of natural resources by paper products is reduced, environmental protection is better facilitated, and the requirement for resource recycling is better met; and the paper biomass charcoal prepared by the preparation method has rich porous structures and large specific surface area, and can be used in the field of adsorbent materials.

Description

Technical Field

[0001] The present invention relates to the technical field of resource recycling, and in particular to a paper biochar and a preparation method and application thereof. Background Art

[0002] In today's society where resources are becoming increasingly scarce, the recycling of waste paper resources has become a focus of current research. After losing its use function, paper is generally incinerated or recycled into recycled paper, thereby achieving the effect of waste treatment or waste utilization. However, incineration will cause waste emissions and cause environmental pollution problems, and paper recycling will also use a large amount of water resources and produce more wastewater, causing environmental pollution, which does not meet environmental protection requirements.

[0003] At present, a new paper processing method has emerged in the prior art to address the above-mentioned problems, which is to produce fertilizer by degrading waste paper with microorganisms. Although this method solves the pollution problem caused by the recycling of waste paper, the method of producing fertilizer returns the waste paper to nature, which will force people to continue to develop and utilize new forest resources when reproducing paper products, which is not conducive to the protection of natural resources and leads to over-exploitation of natural resources.

[0004] Therefore, there is an urgent need to provide a method for preparing paper biochar using paper waste, so that it can solve the pollution problems caused by the recycling and reuse of paper waste and the problem of excessive use of natural resources. Summary of the invention

[0005] The purpose of the present invention is to provide a paper biochar and a preparation method and application thereof. The preparation method of the paper biochar provided in the present application will not cause new environmental pollution problems in the process of recycling and reusing waste paper, and the prepared paper biochar can be used in the field of adsorption materials, reducing the exploitation of natural resources and being more conducive to the protection of natural resources.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing paper biochar, comprising the following steps:

[0008] (1) soaking paper waste in water to obtain paper pulp; stirring while soaking;

[0009] (2) mixing the pulp obtained in step (1) with an oxidant to carry out an oxidation reaction to obtain oxidized pulp;

[0010] (3) The oxidized paper pulp obtained in step (2) is subjected to freeze-thaw treatment and carbonization treatment in sequence to obtain paper biochar.

[0011] Preferably, the paper waste in step (1) includes one or more of newspapers, office paper, books and express boxes.

[0012] Preferably, in step (1), the mass ratio of water to paper waste is (10-30):1.

[0013] Preferably, the soaking time in step (1) is 12 to 18 hours.

[0014] Preferably, the oxidant in step (2) is one or both of sodium hypochlorite and hydrogen peroxide solution.

[0015] Preferably, the mass of the sodium hypochlorite is 4-6 g / L of the pulp volume; the volume of the hydrogen peroxide solution is 5-10% of the pulp volume; and the ratio of the mass of the sodium hypochlorite to the mass of the hydrogen peroxide in the mixture of the sodium hypochlorite and the hydrogen peroxide solution is 1:(0.5-1).

[0016] Preferably, the freezing temperature in the freeze-thaw treatment in step (3) is -60 to -40°C, and the melting temperature in the freeze-thaw treatment is room temperature; the number of freeze-thaw treatments is 1 to 3 times.

[0017] Preferably, in step (3), the temperature of the carbonization treatment is 450-550° C., the time of the carbonization treatment is 1.5-3 hours, and the atmosphere of the carbonization treatment is nitrogen.

[0018] The present invention also provides a paper biochar prepared by the preparation method described in the above technical solution.

[0019] The present invention also provides a paper biomass charcoal prepared by the preparation method described in the above technical solution or the use of the paper biomass charcoal described in the above technical solution in an adsorbent material.

[0020] The present invention also provides a paper biomass charcoal prepared by the preparation method described in the above technical solution or the use of the paper biomass charcoal described in the above technical solution in an adsorbent material.

[0021] The technical solution of the present invention provides a method for preparing paper biochar, comprising the following steps: crushing paper waste and soaking it in water to obtain pulp; stirring while soaking; mixing the pulp obtained above with an oxidant for oxidation reaction to obtain oxidized pulp; and sequentially subjecting the oxidized pulp obtained above to freeze-thaw treatment and carbonization treatment to obtain paper biochar. The present invention can obtain a relatively uniform pulp by crushing and then soaking the paper waste, which is more conducive to full contact with the oxidant to achieve modification; the addition of the oxidant can effectively pre-treat the pulp so that it obtains more oxygen-containing groups, and after freeze-thaw treatment and carbonization treatment, the pulp fiber can obtain a richer porous structure, which is more conducive to use as an adsorbent material. The preparation method of the present invention is simple to operate, reduces the environmental pollution generated in the process of regenerating paper products from paper waste, and also reduces the over-exploitation of natural resources for paper products, which is more conducive to environmental protection and more in line with the requirements of resource recycling; and the paper biochar prepared by the preparation method of the present invention has a rich porous structure and a large specific surface area, and can be used in the field of adsorbent materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a SEM image of the paper biochar product prepared in Example 1 of the present invention;

[0023] Figure 2 This is the XRD diagram of the paper biochar product prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] The present invention provides a method for preparing paper biochar, comprising the following steps:

[0025] (1) soaking paper waste in water to obtain paper pulp; stirring while soaking;

[0026] (2) mixing the pulp obtained in step (1) with an oxidant to carry out an oxidation reaction to obtain oxidized pulp;

[0027] (3) The oxidized paper pulp obtained in step (2) is subjected to freeze-thaw treatment and carbonization treatment in sequence to obtain paper biochar.

[0028] The invention soaks paper waste in water to obtain paper pulp.

[0029] In the present invention, the paper waste preferably includes one or more of newspapers, office paper, books and express boxes.

[0030] In the present invention, the paper waste is preferably crushed before being soaked in water. The present invention has no requirements on the size of the crushed paper waste, and the paper waste can be crushed into paper scraps using a crushing device well known to those skilled in the art. The present invention is more conducive to fully soaking the paper waste and obtaining uniform pulp by crushing the paper waste.

[0031] In the present invention, the soaking time is preferably 12 to 18 hours, more preferably 13 to 17 hours, and most preferably 14 to 16 hours. The present invention can fully swell the fibers in the paper waste by soaking and controlling the soaking time within the above range, which is more conducive to obtaining loose and porous paper biochar with a large specific surface area.

[0032] In the present invention, the soaking is performed while stirring; the stirring rate is preferably 400 to 700 rpm, more preferably 500 to 600 rpm. The present invention is more conducive to obtaining uniform pulp by stirring while soaking and controlling the stirring rate within the above range.

[0033] In the present invention, the mass ratio of water to paper waste is preferably (10-30): 1, more preferably (15-25): 1, and most preferably 20: 1. By controlling the mass ratio of water to paper waste within the above range, the present invention can make the paper waste fully swell and disperse in water, thereby obtaining a more uniform pulp, which is more conducive to obtaining paper biochar with a rich porous structure.

[0034] After soaking is completed, the present invention preferably adjusts the pH value of the soaked product to obtain pulp. In the present invention, the pH value of the pulp is preferably 4.8 to 5.5. The present invention has no requirements for the method of adjusting the pH value, and the method of adjusting the pH value well known to those skilled in the art can be used to make the pH value meet the requirements. By adjusting the pH value of the pulp, the present invention can reduce the decomposition of the oxidant, which is more conducive to the full oxidation of the pulp.

[0035] After obtaining the pulp, the present invention mixes the pulp with an oxidant to carry out an oxidation reaction to obtain oxidized pulp.

[0036] In the present invention, the oxidant is preferably one or both of sodium hypochlorite and hydrogen peroxide solution.

[0037] In the present invention, the mass of the sodium hypochlorite is preferably 4-6 g / L of the pulp volume, more preferably 5 g / L.

[0038] In the present invention, the volume of the hydrogen peroxide solution is preferably 5-10% of the volume of the pulp, more preferably 6-9%, and most preferably 7-8%. In the present invention, the hydrogen peroxide solution is preferably an analytically pure solution with a mass fraction of 30%.

[0039] In the present invention, the ratio of the mass of sodium hypochlorite to the mass of hydrogen peroxide in the mixture of sodium hypochlorite and hydrogen peroxide solution is preferably 1:(0.5-1), more preferably 1:(0.6-0.9), more preferably 1:(0.7-0.8). The present invention can make the fiber surface in the pulp obtain more oxygen-containing groups by adding an oxidant to the pulp, selecting the above oxidant and controlling the usage amount of each oxidant, which is more conducive to obtaining a rich porous structure and a higher specific surface area.

[0040] In the present invention, the oxidation reaction is preferably carried out under stirring conditions; the stirring rate is preferably 900-1100 rpm, more preferably 1000 rpm. The present invention adopts a stirring method and controls the stirring rate within the above range, which is more conducive to uniform mixing of pulp and oxidant and sufficient oxidation of pulp, so that the fiber surface in the pulp obtains more hydroxyl groups, which is more conducive to obtaining a rich porous structure.

[0041] In the present invention, the oxidation reaction time is preferably 2 to 6 hours, more preferably 3 to 5 hours. The present invention controls the oxidation time within the above range, which is more conducive to the oxidant fully oxidizing the pulp, so that the fiber surface in the pulp obtains more hydroxyl groups, which is more conducive to obtaining a rich porous structure.

[0042] After obtaining the oxidized paper pulp, the present invention sequentially performs freeze-thaw treatment and carbonization treatment on the oxidized paper pulp to obtain paper biomass charcoal.

[0043] In the present invention, the oxidized pulp is preferably filtered before freeze-thaw treatment. The present invention has no special requirements for the filtering operation, and a filtering operation well known to those skilled in the art can be used to remove most of the water in the pulp and retain the solid matter.

[0044] In the present invention, the freezing temperature in the freeze-thaw treatment is preferably -60 to -40°C, more preferably -55 to -45°C; the freezing time in the freeze-thaw treatment is preferably 6 to 8 hours, more preferably 7 hours; the melting temperature in the freeze-thaw treatment is preferably room temperature; the number of freeze-thaw treatments is preferably 1 to 3 times, more preferably 2 times. The present invention has no requirements for the thawing time, as long as the frozen pulp material can be completely melted. The present invention can dry the oxidized pulp and initially obtain a rich porous structure by performing a freeze-thaw treatment and controlling the parameters of the freeze-thaw treatment within the above range.

[0045] In the present invention, the freeze-thaw treatment is preferably performed under vacuum conditions; the vacuum degree of the freeze-thaw treatment is preferably 10-15 Pa, more preferably 12 Pa. The present invention can better maintain the oxidized state of the oxidized pulp by controlling the vacuum degree of the freeze-thaw treatment within the above range.

[0046] In the present invention, the temperature of the carbonization treatment is preferably 450-550°C, more preferably 500°C; the time of the carbonization treatment is preferably 1.5-3h, more preferably 2-2.5h; the atmosphere of the carbonization treatment is preferably nitrogen. The present invention can pyrolyze organic matter such as fiber and lignin in the freeze-thaw treated paper material to retain long carbon chains, obtain a rich porous structure, and have a high specific surface area by performing carbonization treatment and controlling its parameters within the above range.

[0047] The preparation method of paper biomass charcoal provided by the present invention is simple to operate, reduces the environmental pollution generated in the process of regenerating paper products from paper waste, and also reduces the over-exploitation of resources for paper products, which is more conducive to environmental protection and more in line with the requirements of resource recycling; and the paper biomass charcoal prepared by the preparation method of the present invention has a rich porous structure and a large specific surface area, and can be used in the field of adsorbent materials.

[0048] The present invention also provides a paper biochar prepared by the preparation method described in the above technical solution.

[0049] The paper biochar provided by the invention has a rich porous structure and a large specific surface area.

[0050] The present invention also provides a paper biomass charcoal prepared by the preparation method described in the above technical solution or the use of the paper biomass charcoal described in the above technical solution in an adsorbent material.

[0051] The application provided by the present invention enables paper biomass charcoal to be used in the field of adsorption materials, thereby reducing the exploitation of natural resources and being more conducive to the protection of natural resources.

[0052] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Example 1

[0054] An experiment was conducted on the collection of office paper generated daily by an office enterprise in Hebei Province. The unit's waste paper was treated in the same way as a general solid waste treatment plant, with an average quarterly paper usage of 50,000 sheets.

[0055] Step 1: First, 100 g of waste paper that has been shredded by a shredder is soaked in 1000 g (1000 mL of deionized water) of water, and stirred at room temperature at a speed of 400 rpm for 18 hours to obtain uniform pulp.

[0056] Step 2: The pH of the pulp is adjusted to between 4.8 and 5.5, sodium hypochlorite is added to the pulp with the adjusted pH value, and the mixture is stirred and oxidized at 1000 rpm for 3 hours at room temperature to obtain oxidized pulp; wherein the mass of sodium hypochlorite is 5 g / L of the pulp volume.

[0057] Step 3: Take 200 mL of the oxidized pulp in the above step 2 and filter it. The obtained pulp is placed in an alumina crucible and placed in a freezing temperature of -58°C, a freezing time of 6 hours, a vacuum degree of 12 Pa, and a melting condition of room temperature. The freeze-thaw treatment is performed for 6 hours, and the freeze-thaw treatment process is repeated twice; then the carbonization treatment is performed in a tubular furnace set at 500°C for 2 hours, with a nitrogen atmosphere protected throughout the process. After cooling to room temperature, paper biochar is obtained, and the mass of the biochar is weighed to be 0.7294 g.

[0058] Example 2

[0059] An experiment was conducted on the collection of office paper generated daily by an office enterprise in Hebei Province. The unit's waste paper was treated in the same way as a general solid waste treatment plant, with an average quarterly paper usage of 50,000 sheets.

[0060] Step 1: First, 100 g of waste paper that has been shredded by a shredder is soaked in 1000 g (1000 mL of deionized water) of water, and stirred at room temperature at a speed of 400 rpm for 18 hours to obtain uniform pulp.

[0061] Step 2: The pH of the above pulp is adjusted between 4.8 and 5.5, and a hydrogen peroxide solution (30% by mass of analytically pure hydrogen peroxide solution) is mixed with the pulp with the adjusted pH, and after waiting for no more violent reaction, the mixture is stirred and oxidized at 1000 rpm for 3 hours at room temperature to obtain oxidized pulp; wherein the volume of the hydrogen peroxide solution is 7% of the volume of the pulp.

[0062] Step 3: Take 200 mL of the oxidized pulp in the above step 2 and filter it. The obtained pulp is placed in an alumina crucible, and the freezing temperature is -58°C, the freezing time is 6 hours, the vacuum degree is 12 Pa, and the melting condition is room temperature. The freeze-thaw process is repeated twice; then it is carbonized in a tubular furnace set at 500°C for 2 hours, with nitrogen atmosphere protection throughout the process. After cooling to room temperature, paper biochar is obtained, and the mass of the biochar is weighed to be 0.7401 g.

[0063] Comparative Example 1

[0064] The freeze-thaw treatment in step 3 of Example 1 was replaced by drying in an oven at 65° C. for 2 h. The paper-like biochar obtained in step 3 of Comparative Example 1, which was finally cooled to room temperature, had a total weight of 0.0603 g.

[0065] The microstructure of the paper biochar product prepared in Example 1 was observed using a scanning electron microscope. The results were as follows: Figure 1 shown.

[0066] Depend on Figure 1 It can be seen that paper biochar is composed of intersecting fibrous carbon structures and has a rich porous structure.

[0067] The paper biochar product prepared in Example 1 was subjected to phase analysis using an X-ray diffractometer. The analysis results are as follows: Figure 2 shown.

[0068] Depend on Figure 2 It can be seen that the paper biochar finally prepared by the present invention is a carbon material, which can prove that the present invention can process paper waste into economically beneficial carbon materials, is simple to operate, saves resources, and reduces environmental pollution.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing paper biochar, comprising the following steps: (1) soaking paper waste in water to obtain paper pulp; stirring while soaking; (2) mixing the pulp obtained in step (1) with an oxidant to carry out an oxidation reaction to obtain oxidized pulp; (3) The oxidized paper pulp obtained in step (2) is subjected to freeze-thaw treatment and carbonization treatment in sequence to obtain paper biochar.

2. The preparation method according to claim 1, characterized in that: The paper waste in step (1) includes one or more of newspapers, office paper, books and express boxes.

3. The preparation method according to claim 1, characterized in that: In the step (1), the mass ratio of water to paper waste is (10-30):

1.

4. The preparation method according to claim 1, characterized in that: The soaking time in step (1) is 12 to 18 hours.

5. The preparation method according to claim 1, characterized in that: The oxidant in step (2) is one or both of sodium hypochlorite and hydrogen peroxide solution.

6. The preparation method according to claim 5, characterized in that: The mass of the sodium hypochlorite is 4-6 g / L of the pulp volume; the volume of the hydrogen peroxide solution is 5-10% of the pulp volume; and the ratio of the mass of the sodium hypochlorite to the mass of the hydrogen peroxide in the mixture of the sodium hypochlorite and the hydrogen peroxide solution is 1:(0.5-1).

7. The preparation method according to claim 1, characterized in that: The freezing temperature in the freeze-thaw treatment in step (3) is -60 to -40°C, and the melting temperature in the freeze-thaw treatment is room temperature; the number of freeze-thaw treatments is 1 to 3 times.

8. The preparation method according to claim 1, characterized in that: The temperature of the carbonization treatment in step (3) is 450-550° C., the time of the carbonization treatment is 1.5-3 hours, and the atmosphere of the carbonization treatment is nitrogen.

9. A paper-like biochar prepared by the preparation method according to claims 1 to 8.

10. Use of the paper biochar prepared by the preparation method according to claims 1 to 8 or the paper biochar according to claim 9 in an adsorbent material.

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