Biomass fuel containing water-based sediment and residual bait mixture and preparation method thereof

Abstract

The present invention belongs to the technical field of biomass fuel preparation, and specifically relates to a biomass fuel containing a mixture of aquatic sediment and residual bait, and a preparation method thereof. The preparation method comprises the following steps: (1) dehydrating and drying the aquatic sediment and residual bait mixture, and crushing it to obtain a substrate raw material; (2) cutting coconut palm into sections and crushing it to obtain coconut palm powder; (3) uniformly mixing the substrate raw material with coconut palm powder, anti-coking additives and oyster shell powder, and granulating the mixture through a granulator to obtain biomass fuel. The present invention uses aquaculture substrate waste as the main raw material, which not only reduces the pressure of tail water treatment in the high-density aquaculture industry, but also reduces the breeding cost by resource utilization of aquaculture sediments. It also provides a new way for the processing of biomass fuel, while increasing economic benefits. The process is simple and the application prospects are broad. While providing a guarantee for the healthy development of the high-density aquaculture industry, it also achieves the purpose of energy saving and environmental protection.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass fuel preparation, and particularly relates to a biomass fuel containing a water-based bottom mud and residual bait mixture and a preparation method thereof. Background Art

[0002] As energy demand continues to grow, humanity urgently needs to adjust its energy structure and reduce its dependence on traditional fossil energy. Biomass is internationally recognized as a low-carbon, clean, and renewable energy source. In a broad sense, biomass fuels include all solid, liquid, or gaseous fuels composed of or extracted from biomass. Biomass resources come from a wide range of sources, including agricultural and forestry waste, urban biosolids and waste, water-based or land-based vegetation, and energy crops. They are renewable energy sources with the advantages of energy conservation, environmental protection, and high calorific value. In order to meet renewable energy goals, they can, to a certain extent, replace gasoline and diesel derived from petroleum. Foreign countries have long started using biomass energy for heating, with consumption significantly exceeding production and supply, and the proportion of biomass energy in renewable energy continues to increase. Domestic research on biomass fuels is also becoming increasingly extensive.

[0003] Patent publication number CN106433841A discloses a biomass fuel containing lignin, made from the following raw materials: biomass sludge containing straw ash, straw ash, lignin, and cellulose sludge. By adding plant materials such as straw ash to undewatered sludge, the calorific value of the dehydrated sludge can be increased. Patent publication number CN102703155A discloses a sludge-straw-coal biomass fuel, its preparation method, and the use of fuel slag. The biomass fuel is obtained by mixing raw coal with the sludge-straw mixture and pressing it into shape.

[0004] Aquaculture, one of the fastest-growing agricultural sectors, plays a vital role in ensuring market supply, increasing farmers' incomes, optimizing national dietary patterns, and ensuring food security. However, with increasing stocking density and feed inputs, large amounts of residual bait, feces, and other sediment deposits accumulate at the bottom of ponds, creating pressure on wastewater treatment and leading to a range of water pollution issues. However, there are currently few reports on using aquatic sediment and residual bait mixtures as raw materials for biomass fuel production or the resource utilization of aquaculture byproducts. Summary of the Invention

[0005] In response to the shortcomings and deficiencies of the above-mentioned prior art, the present invention aims to provide a biomass fuel containing a mixture of aquatic sediment and residual bait, and a method for preparing the same. The present invention innovatively uses aquaculture sediment byproducts as the primary raw material for forming biomass fuel. By adjusting and controlling the formulation ratio and preparation method, the present invention reduces the processing difficulty and production cost of the biomass fuel, increases the fuel calorific value of the biomass fuel, and reduces the release of harmful substances. This has broad prospects for industrial application. While realizing the resource utilization of aquaculture byproducts, it also provides new ideas for the field of biomass fuel processing.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0008] (1) dehydrating and drying the aquatic sediment residual bait mixture, and crushing it to obtain a substrate raw material;

[0009] (2) coconut palm is obtained after segmentation pulverization with coconut palm powder;

[0010] (3) The substrate raw material is evenly mixed with coconut palm powder, anti-coking additive and oyster shell powder, and the mixture is granulated by a granulator to obtain biomass fuel.

[0011] Furthermore, the aquatic sediment and residual bait mixture in step (1) comprises the following components by weight: 40-60% fish excrement, 20-40% sediment, and 20-30% residual feed. The aquatic sediment and residual bait mixture is mainly derived from the bottom of aquaculture ponds, and its bottom sediment content will vary depending on the type of fish being raised and the feed they are fed.

[0012] Furthermore, the dehydration in step (1) refers to dehydrating the material using a filter press to reduce the moisture content of the material to below 40%.

[0013] Furthermore, the drying in step (1) refers to drying the material at 40-80° C. for 12-60 hours in a blast drying oven to reduce the moisture content of the material to below 20%.

[0014] Furthermore, the pulverization in steps (1) and (2) refers to pulverization to 30-50 mesh.

[0015] Furthermore, the coconut palm in step (2) is a filamentous material derived from the shell of coconut and is a common natural biomass raw material.

[0016] Furthermore, the anti-coking additive in step (3) is one or a mixture of kaolin and metakaolin. The main mineral components are kaolinite (Al4[Si4O 10](OH)8), with a content of more than 90%, is a common natural clay mineral.

[0017] Furthermore, the oyster shell powder in step (3) is a product of crushed oyster shells, and its calcium carbonate content is 95-99%.

[0018] Furthermore, the ratio of the raw materials in step (3) in parts by weight is: 5-20 parts of substrate raw materials, 70-90 parts of coconut palm powder, 4-8 parts of anti-coking additives, and 1-4 parts of oyster shell powder.

[0019] Furthermore, the biomass fuel obtained by granulation in step (3) has a diameter of 6 to 10 mm and a length of 20 to 50 mm.

[0020] A biomass fuel is prepared by the above method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The raw materials of the biomass fuel provided by the present invention include aquaculture substrate by-products, coconut palm, oyster shell powder and anti-coking additives; the raw materials are simple and easy to obtain, and the aquaculture substrate by-products are resourced, which greatly reduces a series of environmental pollution caused by fishery aquaculture tail water, protects the local environmental ecological functions, and brings additional economic benefits while reducing processing costs.

[0023] (2) The present invention only uses natural materials such as oyster shells and kaolin as calcium source additives and anti-coking agent additives. Oyster shells are a common waste in aquaculture, and their main component is calcium carbonate. This design uses them as natural additives in the preparation of biomass fuel, replacing traditional calcium additives and reducing harmful gas emissions. The method has a simple and easy operation procedure, does not require the addition of additional chemical agents, and the preparation process is green and environmentally friendly.

[0024] (3) The biomass fuel obtained by the present invention has good compressibility and high combustion efficiency; it is easy to manufacture, store and transport. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram showing the appearance of the molded biomass fuel obtained in an embodiment of the present invention.

[0026] Figure 2 Graph showing the content of different elements in the biomass fuels obtained in Examples 1 to 3 of the present invention, control group 1 (substrate raw material), and control group 2 (coconut coir). DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0028] Example 1

[0029] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0030] (1) A mixture of aquatic bottom mud and residual bait (derived from the bottom of an aquaculture pond, with its components estimated to be in the following range: 40-60% fish excrement, 20-40% bottom mud, and 20-30% residual feed) is dehydrated through a filter press to a water content of less than 40%, and then placed in a forced air drying oven at 60°C for 48 hours, and then placed in a grinder for pulverization and collected through a 40-mesh sieve for later use, to obtain a bottom material with a water content of about 10wt%.

[0031] (2) get coconut palm silk, put it into pulverizer after being cut into small pieces and pulverize, the coconut palm powder after pulverizing is crossed 40 mesh sieves and is collected for standby use, obtains coconut palm powder.

[0032] (3) By weight, 15 parts of substrate raw material, 79 parts of coconut palm powder, 5 parts of anti-coking additive kaolin and 1 part of oyster shell powder (the product of oyster shell after crushing, the calcium carbonate content of which is in the range of 95-99%) were mixed evenly, and the mixture was granulated by a granulator to obtain biomass fuel with a diameter of 7 mm and a length of 30-50 mm. The appearance morphology and element content of the obtained molded biomass fuel are shown in Figure 2. Figure 1 and Figure 2 shown.

[0033] Example 2

[0034] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0035] Steps (1) and (2) are the same as in Example 1.

[0036] (3) By weight, 15 parts of substrate raw materials were mixed evenly with 75 parts of coconut palm powder, 8 parts of anti-coking additive metakaolin and 2 parts of oyster shell powder. The mixture was granulated by a granulator to obtain biomass fuel with a diameter of 8 mm and a length of 30 to 50 mm. The element content of the obtained shaped biomass fuel is shown in the figure below. Figure 2 shown.

[0037] Example 3

[0038] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0039] Steps (1) and (2) are the same as in Example 1.

[0040] (3) By weight, 8.5 parts of substrate raw materials were mixed with 85 parts of coconut palm powder, 5 parts of anti-coking additive (kaolin and metakaolin with a mass ratio of 1:1) and 1.5 parts of oyster shell powder. The mixture was granulated by a granulator to obtain biomass fuel with a diameter of 10 mm and a length of 40-50 mm. The element content of the obtained shaped biomass fuel is shown in the figure Figure 2 shown.

[0041] Control group 1

[0042] This control group uses the substrate raw material obtained in Example 1. Its element content is shown in the figure below. Figure 2 shown.

[0043] Control group 2

[0044] The control group used the coconut palm silk raw material in Example 1. Its element content is shown in the figure below. Figure 2 shown.

[0045] Control group 3

[0046] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait, compared with Example 1, uses an equal amount of dried and crushed corn straw biomass instead of coconut palm powder, and the rest are the same.

[0047] The dry calorific value and fuel density of the biomass fuel samples obtained in Examples 1 to 3 and Control Groups 1 to 3 were measured, and their energy density was calculated. The results are shown in Table 1 below.

[0048] Table 1

[0049] sample Dry basis calorific value kcal / kg <![CDATA[Fuel density g / cm 3 > <![CDATA[Energy density kcal / m 3 > Example 1 3678 1.34 4928.52 Example 2 3737 1.25 4671.25 Example 3 3927 1.26 4948.02 Control group 1 693 2.21 1531.53 Control group 2 4307 0.53 2282.71 Control group 3 3256 1.12 3646.72

[0050] Example 4

[0051] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0052] (1) The aquatic sediment and residual bait mixture (same as in Example 1) is dehydrated through a filter press to a water content of less than 40%, and then placed in a blast drying oven at 50°C for 48 hours. The mixture is then pulverized in a grinder and collected through a 30-mesh sieve for later use, thereby obtaining a substrate raw material with a water content of approximately 14 wt%.

[0053] (2) get coconut palm silk, put it into pulverizer after being cut into small pieces and pulverize, the coconut palm powder after pulverizing is crossed 30 mesh sieves and is collected for standby use, obtains coconut palm powder.

[0054] (3) By mass, 5 parts of substrate raw material were mixed evenly with 90 parts of coconut palm powder, 4 parts of kaolin, an anti-coking additive, and 1 part of oyster shell powder. The mixture was granulated by a granulator to obtain biomass fuel with a diameter of 6 mm and a length of 20 to 40 mm. The energy density of the biomass fuel obtained in this embodiment was calculated to be 4896.65 kcal / m 3 .

[0055] Example 5

[0056] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait comprises the following steps:

[0057] (1) The aquatic sediment and residual bait mixture (same as in Example 1) is dehydrated through a filter press to a water content of less than 40%, and then placed in a blast drying oven at 80°C for 12 hours, and then placed in a grinder for pulverization and collected through a 50-mesh sieve for later use, to obtain a substrate raw material with a water content of about 8wt%.

[0058] (2) get coconut palm silk, put it into pulverizer after being cut into small pieces and pulverize, the coconut palm powder after pulverizing is crossed 50 mesh sieves and is collected for standby use, obtains coconut palm powder.

[0059] (3) By mass, 20 parts of substrate raw material, 70 parts of coconut palm powder, 8 parts of kaolin, an anti-coking additive, and 2 parts of oyster shell powder were mixed evenly, and the mixture was granulated by a granulator to obtain a biomass fuel with a diameter of 9 mm and a length of 40 to 50 mm. The energy density of the biomass fuel obtained in this embodiment was calculated to be 4627.36 kcal / m 3 .

[0060] It can be seen from the above results that the biomass fuel particles prepared by the present invention are firmly combined and should not be loose. They also have the advantages of being easy to make, low cost, and economical. The dry basis calorific value of the biomass molded fuel produced by the present invention is 3678-3927kcal / kg, which is higher than the average calorific value of 3585kcal / kg of biomass fuels made from traditional crop residues (corn stalks, rice straw), thereby realizing efficient resource utilization of aquaculture by-products. At the same time, the biomass molded fuel obtained by using coconut palm powder in combination with substrate raw materials has significantly improved calorific value and energy density compared to other biomasses (such as commonly used corn stalks). The biomass molded fuel prepared by the present invention has high energy density and high specific gravity, and can provide 4627.36-4948.02kcal of heat per unit volume of fuel. At the same time, it greatly improves the shortcomings of aquaculture substrate by-products and coconut palm in low energy utilization, large space volume, and difficulty in storage and transportation.

[0061] Control group 4

[0062] A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait, compared with Example 1, without adding the anti-coking additive kaolin, and other aspects are the same.

[0063] Control group 5

[0064] A method for preparing a biomass fuel containing a mixture of water-derived sediment and residual bait, compared with Example 1, except that oyster shell powder is not added, and the rest are the same.

[0065] The dry calorific value, slagging rate (determined in accordance with the provisions of NY / T1881.5-2010 "Test Method for Biomass Solid Molded Fuel Part 5: Ash") and S and Cl element fixation rate (S and Cl element content in combustion slag / S and Cl element content in biomass fuel * 100%) of the biomass fuel samples obtained in Example 1 and Control Groups 4 to 5 above were tested, and the results are shown in Table 2 below.

[0066] Table 2

[0067] sample Dry basis calorific value kcal / kg Slagging rate% S element fixation rate % Cl element fixation rate % Example 1 3678 10.52 85.6 79.2 Control group 4 2853 12.60 74.9 72.7 Control group 5 3590 9.37 10.5 25.1

[0068] As can be seen from the results in Table 2, the biomass briquette fuel prepared by the present invention can significantly promote the combustion of substrate raw materials, increase calorific value and reduce slagging rate by adding anti-coking additives, and also has a certain effect on the fixation of S and Cl elements. The addition of oyster shell powder can significantly enhance the fixation effect of S and Cl elements. It effectively avoids the problems of boiler coking and slagging, high-temperature chlorine corrosion, etc. that traditional biomass fuels often produce during combustion, and reduces the emission of harmful gases such as SO2. This is attributed to the added natural oyster shell powder and kaolin acting as calcium additives and anti-coking additives, respectively. During the high-temperature combustion process, the Ca element in the oyster shell powder and the Al-Si-OO structural unit in the kaolin fix the S element, alkali metal elements and Cl elements that are gasified at high temperature. Therefore, the biomass briquette fuel prepared by the present invention is a renewable clean energy that can be widely used in biomass boilers, domestic stoves, and biomass power generation. At the same time, it realizes the treatment of aquaculture bottom waste, which not only reduces the pressure of tail water treatment in the high-density aquaculture industry, but also reduces the breeding cost through resource utilization of aquaculture bottom mud, while increasing economic benefits. It provides guarantees for the healthy development of the high-density aquaculture industry while achieving the goal of energy conservation and environmental protection.

[0069] The above embodiments are preferred implementations of the present invention, but the implementations of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a biomass fuel containing a mixture of water-producing sediment and residual bait, characterized in that: The steps include: (1) Dehydrating and drying the aquatic sediment and residual bait mixture, and then crushing it to obtain the bottom material raw material; (2) cutting the coconut palm into sections and crushing them to obtain coconut palm powder; (3) uniformly mixing the substrate raw material with coconut palm powder, anti-coking additive and oyster shell powder, and pelletizing the mixture through a pelletizer to obtain biomass fuel; The aquatic sediment and residual bait mixture in step (1) comprises the following components in percentage by mass: 40-60% fish excrement, 20-40% sediment and 20-30% residual feed; The anti-coking additive in step (3) is one or a mixture of kaolin and metakaolin; the oyster shell powder is a product of crushed oyster shells, and its calcium carbonate content is 95-99%; The weight ratio of the raw materials in step (3) is: 5-20 parts of substrate raw materials, 70-90 parts of coconut palm powder, 4-8 parts of anti-coking additives, and 1-4 parts of oyster shell powder.

2. The method for preparing a biomass fuel containing a water-containing bottom mud and residual bait mixture according to claim 1, characterized in that: The dehydration in step (1) refers to dehydration using a filter press to reduce the moisture content of the material to below 40%.

3. The method for preparing a biomass fuel containing a water-containing bottom mud and residual bait mixture according to claim 1, characterized in that: The drying in step (1) refers to drying the material at 40-80°C for 12-60 hours in a blast drying oven to reduce the moisture content of the material to below 20%.

4. The method for preparing a biomass fuel containing a water-containing bottom mud and residual bait mixture according to claim 1, characterized in that: The pulverization in steps (1) and (2) refers to pulverization to 30-50 mesh.

5. The method for preparing a biomass fuel containing a water-based sediment and residual bait mixture according to claim 1, wherein: The biomass fuel obtained by granulation in step (3) has a diameter of 6-10 mm and a length of 20-50 mm.

6. A biomass fuel, characterized in that: It is prepared by the method according to any one of claims 1 to 5.

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