Edible mushroom residue processing method, graphene and application thereof

Abstract

The present invention belongs to the technical field of carbon materials, and specifically relates to a method for processing edible fungus residue, graphene and its application. The method for processing edible fungus residue provided by the present invention comprises the following steps: mixing edible fungus residue and polyethylene plastic and pyrolyzing them to obtain graphene; the edible fungus residue contains calcium, and the content of calcium in the edible fungus residue is greater than 1000 mmol / kg. During the pyrolysis process of the edible fungus residue and polyethylene plastic, the polyethylene plastic produces a large number of hydrocarbon free radicals, which promote the in-depth decomposition of the edible fungus residue and obtain precursors that are beneficial for the preparation of graphene; the calcium in the edible fungus residue promotes the interaction between the edible fungus residue and the polyethylene material to obtain more graphene precursors while promoting the catalytic conversion of the graphene precursors, guiding the orderly growth of carbon atoms, and facilitating the formation of graphene. The method of the present invention not only solves the problem of waste recycling of edible fungus residue, but also realizes the green and low-cost preparation of graphene.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon materials, and in particular relates to a method for processing edible fungus residue, graphene and applications thereof. Background Art

[0002] Edible fungi refer to mushrooms (macrofungi) with large, edible fruiting bodies. Edible fungi are organic, nutritious, and health-promoting green foods. Their cultivation offers the advantages of low investment, short production cycles, and rapid returns, leading to the rapid growth of the edible fungi industry. With this rapid growth, a significant amount of fungus residue, a byproduct of the industry, is also being produced. Mushroom residue is made from a mixture of biomass, such as sawdust, straw, rice husks, and fruit shells. This biomass mixture undergoes pulverization, steam sterilization, inoculation, and fungal growth, resulting in edible fungus residue. As an emerging solid waste, edible fungus residue currently lacks viable utilization options. While a small amount has been explored as fertilizer or feed, challenges such as long composting cycles and uncontrollable properties limit its implementation. The majority is simply discarded or incinerated, occupying land and fostering mold growth, resulting in resource waste and environmental pollution (including air, water, and soil pollution). The proper treatment and disposal of edible fungus residue has become an urgent issue. Summary of the Invention

[0003] In view of this, the present invention provides a method for processing edible fungus residue, graphene and applications thereof. The method for processing edible fungus residue provided by the present invention is simple and easy to operate, and can make resource utilization of edible fungus residue.

[0004] In order to solve the above technical problems, the present invention provides a method for processing edible mushroom residue, comprising the following steps:

[0005] Mixing edible fungus residue and polyethylene plastic and performing pyrolysis to obtain graphene;

[0006] The edible fungus residue contains calcium, and the content of the calcium in the edible fungus residue is greater than 1000 mmol / kg.

[0007] Preferably, the mass ratio of the edible fungus residue to the polyethylene plastic is 10:1 to 1:10.

[0008] Preferably, the pyrolysis temperature is 800-1000° C., and the pyrolysis holding time is 2-5 hours.

[0009] Preferably, the heating rate to the temperature required for pyrolysis is 1-20°C / min.

[0010] Preferably, the mixing further comprises:

[0011] The edible fungus residue is removed from impurities and then dried, crushed and sieved in sequence to obtain edible fungus residue powder.

[0012] Preferably, the polyethylene plastic is waste polyethylene plastic;

[0013] Before the mixing, the method further comprises: washing, drying and then crushing the waste polyethylene plastic to obtain plastic debris.

[0014] Preferably, the waste polyethylene plastics include one or more of waste polyethylene ground films, waste polyethylene plastic bags and waste polyethylene packaging films.

[0015] Preferably, the edible fungus residue is a mushroom stick after cultivating edible fungi, and the edible fungi include one or more of shiitake mushrooms, enoki mushrooms, oyster mushrooms, coprinus comatus, king oyster mushrooms and straw mushrooms.

[0016] The present invention also provides graphene obtained by the edible fungus residue processing method according to the above technical solution, wherein the graphene has a thickness of 1 to 8 nm and the number of carbon layers is 3 to 25.

[0017] The present invention also provides applications of the graphene described in the above technical solution in the fields of high-strength composite material preparation, energy storage or catalysis.

[0018] The present invention provides a method for processing edible mushroom residue, comprising the following steps: mixing the edible mushroom residue with polyethylene plastic and subjecting them to pyrolysis to obtain graphene; the edible mushroom residue contains calcium, wherein the calcium content in the edible mushroom residue is greater than 1000 mmol / kg. In the present invention, during the pyrolysis of the edible mushroom residue and polyethylene plastic, the polyethylene plastic generates a large number of hydrocarbon free radicals, which promote the further decomposition of the edible mushroom residue and obtain a large number of precursors that are beneficial for the preparation of graphene; the calcium in the edible mushroom residue, on the one hand, strengthens the interaction between the edible mushroom residue and the polyethylene material, thereby obtaining more precursors for the preparation of graphene; and on the other hand, promotes the catalytic conversion of the graphene precursor, guiding the orderly growth of carbon atoms, acting as a catalyst, and obtaining a high-value graphene product. The present invention obtains high-value carbon nanomaterial graphene using discarded edible mushroom residue and polyethylene plastic as raw materials, not only solving the problem of waste recycling of edible mushroom residue but also achieving the green and low-cost preparation of high-value carbon nanomaterial graphene. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the SEM image of the pyrolysis product prepared in Example 1;

[0020] Figure 2 TEM image of the pyrolysis product prepared in Example 1;

[0021] Figure 3 This is a thermogravimetric curve of the graphene prepared in Example 1. DETAILED DESCRIPTION

[0022] The present invention provides a method for processing edible fungus residue, comprising the following steps:

[0023] The edible fungus residue and polyethylene plastic are mixed and pyrolyzed to obtain graphene.

[0024] In the present invention, the edible fungus residue is preferably a mushroom stick after cultivating edible fungi, and the edible fungi preferably include one or more of shiitake mushrooms, enoki mushrooms, oyster mushrooms, coprinus comatus, king oyster mushrooms and straw mushrooms.

[0025] In the present invention, the edible fungus residue contains calcium, and the content of calcium in the edible fungus residue is greater than 1000 mmol / kg, preferably 1400-1800 mmol / kg. In the present invention, the ash content of the edible fungus residue is preferably greater than 15%, more preferably 16-24%.

[0026] In the present invention, the polyethylene plastic is preferably waste polyethylene plastic; the waste polyethylene plastic includes one or more of waste polyethylene ground film, waste polyethylene plastic bags and waste polyethylene packaging film.

[0027] In the present invention, the mass ratio of the edible fungus residue to the polyethylene plastic is preferably 1-10:1-10, more preferably 1-2:1.

[0028] In the present invention, the mixing step preferably further comprises:

[0029] After removing impurities from the edible fungus residue, the residue is dried, crushed and sieved in sequence to obtain edible fungus residue powder. In the present invention, the impurity removal is preferably to remove the soil from the edible fungus residue. The present invention has no special requirements for the method of impurity removal, as long as the impurities in the edible fungus residue can be removed. In the present invention, the drying is preferably oven drying, and the oven drying temperature is preferably 100-110°C, more preferably 105°C; the oven drying time is preferably 3-5h, more preferably 4h. The present invention has no special requirements for the pulverization, and conventional methods in the art can be used. In the present invention, the aperture of the sieve for screening is preferably 20-60 mesh, more preferably 30-40 mesh.

[0030] In the present invention, the mixing step preferably further comprises: washing, drying, and then crushing the waste polyethylene plastic to obtain plastic scraps. The present invention has no particular requirements for the washing step, as long as the surface contaminants of the waste polyethylene plastic are completely cleaned. The drying step is also not particularly limited, as long as the solvent on the surface of the waste polyethylene plastic is removed. In the present invention, the size of the crushed product is preferably 0.2 to 2 μm, more preferably 0.5 to 1 μm.

[0031] The present invention has no special requirements for the mixing, as long as the mixing is uniform. In an embodiment of the present invention, the mixing method is preferably grinding.

[0032] In the present invention, the pyrolysis temperature is preferably 800-1000°C, more preferably 800-900°C; the pyrolysis holding time is preferably 2-5 hours, more preferably 2-4 hours. In the present invention, the heating rate to the desired pyrolysis temperature is preferably 1-20°C / min, more preferably 2-10°C / min.

[0033] In the present invention, the pyrolysis is preferably carried out in a protective atmosphere, preferably an inert gas or nitrogen, more preferably nitrogen. In the present invention, the inert gas is preferably argon or helium. In the present invention, the pyrolysis is preferably carried out in a pyrolysis reactor. In the present invention, the pyrolysis reactor preferably includes a tubular furnace, a muffle furnace, a horizontal fixed bed, a vertical fixed bed, or a fluidized bed.

[0034] In the present invention, after the pyrolysis, the process preferably further comprises cooling the pyrolysis system to room temperature. In the present invention, the cooling is preferably air cooling. In the present invention, the room temperature is preferably 20-35°C, more preferably 25-30°C.

[0035] The present invention utilizes calcium-rich edible fungus residue and waste polyethylene plastic to prepare graphene through pyrolysis. The present invention uses calcium-rich, loosely structured edible fungus residue as raw material and pyrolyzes it through pyrolysis with waste polyethylene plastic. On the one hand, the pyrolysis products of the waste polyethylene plastic can capture free radicals that cause condensation and coking of the edible fungus residue, and provide hydrocarbon radicals and hydrogen radicals to deepen the decomposition of the edible fungus residue. At the same time, the calcium minerals in the edible fungus residue play two important roles in the pyrolysis: 1) strengthening the synergistic effect of the edible fungus residue and the waste plastic to obtain a large amount of precursors for preparing graphene; 2) promoting the catalytic decomposition of the graphene precursor, guiding the orderly growth of carbon atoms, and obtaining high-value carbon nanomaterial graphene. Compared with the traditional production process of producing graphene using fossil fuels as raw materials, edible fungus residue is inexpensive and widely available. The present invention reduces the production cost of graphene while realizing the resource utilization of edible fungus residue waste.

[0036] The present invention also provides graphene obtained by the edible fungus residue processing method according to the above technical solution, wherein the thickness of the graphene is 1 to 8 nm, preferably 1 to 5 nm; the number of carbon layers of the graphene is 3 to 25 layers, preferably 3 to 12 layers.

[0037] In the present invention, the graphene has excellent mechanical, thermal and photoelectric properties.

[0038] The present invention also provides the graphene described in the above technical solution for use in the preparation of high-strength composite materials, energy storage, or catalysis.

[0039] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0040] Example 1

[0041] After removing dirt and other impurities from the mushroom sticks, the mushrooms were dried at 105°C for 4 hours. The dried mushroom sticks were crushed and passed through a 40-mesh sieve to obtain mushroom residue powder. The ash content of the mushroom residue powder was 16.72%, and the calcium content was 1406.4 mmol / kg.

[0042] The discarded agricultural polyethylene mulch film is cleaned, dried, and then shredded into pieces with a size of 1 μm to obtain plastic debris;

[0043] Shiitake mushroom residue powder and plastic debris were ground and mixed in a mass ratio of 1:1 and placed in a vertical fixed bed. With nitrogen as the protective gas, the temperature was raised to 800°C at a heating rate of 10°C / min and pyrolyzed for 2 hours, and then naturally cooled to 25°C to obtain graphene.

[0044] Example 2

[0045] After removing impurities such as dirt from the enoki mushroom sticks, the mixture was dried at 105°C for 4 hours. The dried shiitake mushroom sticks were crushed and passed through a 20-mesh sieve to obtain enoki mushroom residue powder. The ash content of the enoki mushroom residue powder was 19.65%, and the calcium content was 1235.8 mmol / kg.

[0046] The waste polyethylene packaging film is cleaned, dried, and then shredded into pieces with a size of 0.5 μm to obtain plastic debris;

[0047] The powder of Flammulina velutipes residue and plastic debris were ground and mixed in a mass ratio of 2:1, and then placed in a horizontal tube furnace. With nitrogen as the protective gas, the temperature was increased to 900°C at a heating rate of 2°C / min, and pyrolyzed for 4 hours, and then naturally cooled to 25°C to obtain graphene.

[0048] The pyrolysis product prepared in Example 1 was examined by scanning electron microscopy to obtain a SEM image, as shown in FIG. Figure 1 The pyrolysis product prepared in Example 1 was examined by transmission electron microscopy to obtain a TEM image, as shown in FIG. Figure 2 As shown. Figure 1 and 2 It can be seen that the product obtained by pyrolysis in Example 1 is a thin-layer graphene with a clustered paper-like structure, with an edge thickness of about 1 to 3 nm and a carbon layer number of about 3 to 8 layers.

[0049] The pyrolysis product prepared in Example 2 was examined by scanning electron microscopy and transmission electron microscopy. The test results showed that the obtained product was a clustered paper-like graphene structure with an edge thickness of about 1 to 5 nm and a carbon layer number of about 3 to 12 layers.

[0050] The graphene prepared in Example 1 was subjected to thermogravimetric analysis to obtain a thermogravimetric curve. Figure 3 As shown, the yield of graphene in Example 1 was calculated to be 9.24% by thermogravimetric peak integration.

[0051] The graphene prepared in Example 2 was subjected to thermogravimetric analysis, and the yield of the graphene in Example 2 was calculated to be 8.82% through thermogravimetric peak integration.

[0052] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for processing edible mushroom residue, comprising the following steps: Mixing edible fungus residue and polyethylene plastic and performing pyrolysis to obtain graphene; The edible fungus residue contains calcium, and the content of calcium in the edible fungus residue is 1400-1800 mmol / kg; The pyrolysis temperature is 800-900° C., the pyrolysis holding time is 2-5 hours, and the heating rate to the temperature required for pyrolysis is 2-10° C. / min.

2. The method for processing edible fungus residue according to claim 1, characterized in that: The mass ratio of the edible fungus residue to the polyethylene plastic is 10:1 to 1:

10.

3. The method for processing edible fungus residue according to claim 1, characterized in that: The mixing also includes: The edible fungus residue is removed from impurities and then dried, crushed and sieved in sequence to obtain edible fungus residue powder.

4. The method for processing edible fungus residue according to claim 1, characterized in that: The polyethylene plastic is waste polyethylene plastic; Before the mixing, the method further comprises: washing, drying and then crushing the waste polyethylene plastic to obtain plastic debris.

5. The method for processing edible fungus residue according to claim 4, characterized in that: The waste polyethylene plastics include: one or more of waste polyethylene ground films, waste polyethylene plastic bags and waste polyethylene packaging films.

6. The method for processing edible fungus residue according to claim 1, characterized in that: The edible fungus residue is the fungus sticks after the edible fungi are cultivated, and the edible fungi include one or more of shiitake mushrooms, enoki mushrooms, oyster mushrooms, coprinus comatus, king oyster mushrooms and straw mushrooms.

7. The graphene obtained by the method for treating edible fungus residue according to any one of claims 1 to 6, characterized in that: The graphene has a thickness of 1 to 8 nm and a carbon layer number of 3 to 25 layers.

8. Use of the graphene according to claim 7 in the preparation of high-strength composite materials, energy storage or catalysis.

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