Device and method for strengthening aerobic deep composting of wet garbage biogas residue

Abstract

This invention provides an apparatus and method for enhancing the aerobic deep composting of wet waste biogas residue. Targeting the dynamic aerobic composting of biogas residue, it employs an improved horizontal mechanical stirring technology and introduces ultra-high temperature aerobic composting technology. The improved horizontal mechanical stirring technology includes modifying the mechanical shaft into a stirring device composed of multiple impellers of different shapes centered on the same axis. The introduction of ultra-high temperature aerobic composting involves repeatedly inoculating the biogas residue with an ultra-high temperature aerobic fermentation agent rich in extreme thermophilic microorganisms during the initial stage of aerobic composting, raising the pile temperature to ultra-high temperature aerobic composting, and introducing a water replenishment system and adding NH4 removal agents. + A method for adding -N additives. This invention can maintain the moisture content and aerobic microbial activity of biogas residue, accelerating the composting and maturation process of biogas residue. It also adds additives to remove NH4. + -N additives can reduce the high concentration of NH4 in biogas residue. + -N inhibits ultra-high temperature aerobic microorganisms, enabling rapid and efficient conversion of biogas residue.

Description

Technical Field

[0001] This invention belongs to the field of solid waste treatment technology, and specifically relates to a device and method for enhancing the aerobic deep composting of wet waste biogas residue. Background Technology

[0002] Anaerobic digestion is a commonly used method for disposing of wet waste in my country, offering advantages such as volume reduction, low energy consumption, and the generation of biogas. However, anaerobic digestion of wet waste produces a large amount of resource-based byproducts—sludge.

[0003] Currently, aerobic composting is an important biotechnology for the harmless treatment and resource utilization of organic waste such as biogas residue. Composting not only removes odors, toxic substances, and pathogens from biogas residue, but the compost products can also serve as soil conditioners, improving soil fertility. Traditional aerobic composting of biogas residue usually employs windrow or static composting methods, but these methods have drawbacks such as long composting cycles, low efficiency, and strong odors. Compared to traditional aerobic composting methods, using a mechanical horizontal aerobic composting system coupled with ultra-high temperature aerobic fermentation bacteria to treat biogas residue can significantly accelerate aerobic maturation efficiency, shorten the aerobic fermentation cycle, and produce fewer odorous substances. This is because the mechanical horizontal aerobic composting system has more efficient mixing, resulting in more sufficient oxygen supply to the material and more efficient degradation of organic matter. Furthermore, the addition of ultra-high temperature aerobic fermentation bacteria allows the pile to reach extremely high temperatures without relying on external heating, utilizing the heat released from the aerobic respiration and metabolic decomposition of organic matter by extreme thermophilic microorganisms. This accelerates the degradation of organic matter and shortens the fermentation cycle. However, this technology has the following technical bottlenecks: (1) Due to the high viscosity of the biogas residue, when the biogas residue exceeds a certain scale during dynamic mechanical mixing, it is easy to cause the mixer to overload and the impeller to be blocked, resulting in the system being unable to operate stably; (2) Compared with the traditional aerobic composting method, the use of mechanical mixing will cause a large amount of water to evaporate rapidly. At the same time, under the ultra-high temperature (≥80℃, the highest temperature can reach 100℃) achieved by introducing ultra-high temperature aerobic fermentation agents, a large amount of water will inevitably evaporate, resulting in low water content and inhibiting the activity of aerobic microorganisms; (3) The biogas residue has high ammonium nitrogen (NH4) + The properties of (-N) inhibit ultra-high temperature aerobic microorganisms, thus affecting the temperature rise of the material and the composting of biogas residue. Therefore, it is necessary to improve this. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a device and method for enhancing the aerobic deep composting of wet waste biogas residue, so as to promote material heating, shorten the fermentation cycle, improve fermentation efficiency, and enhance the harmlessness effect.

[0005] To solve the above problems, the following technical solution is adopted:

[0006] According to a first aspect of this application, an apparatus for enhancing the aerobic deep composting of wet waste biogas residue is provided, comprising a horizontal double-layer fermenter, a mixer, a first conveyor, a second conveyor, and a third conveyor. One end of the first conveyor is disposed corresponding to the feed end of the mixer. One end of the second conveyor is connected to the mixer, and the other end of the second conveyor is connected to the feed end of the horizontal double-layer fermenter. The return end of the horizontal double-layer fermenter is connected to the return end of the mixer through the third conveyor.

[0007] Furthermore, the horizontal double-layer fermenter is equipped with three combined impellers located on the same axis.

[0008] Furthermore, the combined impeller is a turbine-screw-four-blade cyclone impeller, with the three types of impellers having diameters of 0.4-0.6m, an impeller-to-tank diameter ratio of 0.5-0.6, and a rotational speed of 50-300r / min.

[0009] Furthermore, it also includes a water replenishment device, which is connected to the feed end of the horizontal double-layer fermenter.

[0010] Furthermore, the second and third conveyors are respectively a auger conveyor and an auger return material conveyor.

[0011] According to a second aspect of this application, a method for enhancing the aerobic deep composting of wet waste biogas residue is provided, based on the apparatus described above, the method comprising:

[0012] In the initial stage of aerobic composting, the biogas residue is repeatedly inoculated with an ultra-high temperature aerobic fermentation agent rich in extreme thermophilic microorganisms, causing the compost temperature to rise to a high temperature for aerobic fermentation. The ultra-high temperature aerobic fermentation agent is a compound agent composed of microorganisms such as YM bacteria, Bacillus spp., and Thermophilus spp., with a total dosage of 1-4 kg / m³. 3 .

[0013] Furthermore, after the entire process of inoculating with extreme thermophilic bacteria, the moisture content of the biogas residue in the aerobic composting system is maintained at 35-50% by a preset amount of water replenishment.

[0014] Furthermore, zeolite and biogas residue were added to the horizontal double-layer fermenter at a ratio of 1-1.5:10. The cation exchange capacity of the zeolite was 120-160 meq / 100g, in order to reduce the high concentration of NH4 in the biogas residue. + -N

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. Advantages of the improved stirring impeller in the double-layer fermentation machine for bedrooms in this invention: Compared with traditional stirring impellers, the turbine-screw-four-blade cyclone combined stirring impeller in this invention can generate eddies, turbulence, and greater shear force by simultaneously rotating these three types of combined impellers. This allows for uniform mixing of materials in a short time, eliminating gaps between materials, preventing the formation of fluid and solid layers, and enabling it to withstand large-scale stirring of biogas residue. It also ensures more uniform and thorough mixing of the biogas residue, which is more conducive to accelerating its maturation. This further promotes the application of biogas residue in dynamic aerobic composting.

[0017] 2. Advantages of the method for inoculating an ultra-high temperature aerobic composting process using an extreme thermophilic microbial agent according to the present invention: By inoculating with an ultra-high temperature aerobic fermentation agent rich in extreme thermophilic microorganisms, the composting temperature can be rapidly increased to above 80°C (the maximum temperature can reach 100°C) without relying on an external heat source, which is a temperature that traditional high-temperature composting cannot achieve. Compared with ordinary composting, ultra-high temperature composting has significant advantages in promoting the degradation of organic matter, accelerating the composting maturation process, effectively killing harmful substances such as insect eggs, and controlling secondary pollution during the composting process.

[0018] 3. The present invention adds the advantage of an automatic water replenishment system: By adding an automatic water replenishment system, the problem of large-scale evaporation of moisture in biogas residue caused by ultra-high temperature and dynamic horizontal mechanical stirring is solved, maintaining the moisture content of biogas residue and the activity of aerobic microorganisms, and accelerating the composting and maturation process of biogas residue is solved.

[0019] 4. This invention employs a highly efficient and rapid adsorption method to remove NH4. + Advantages of the -N additive method: By introducing zeolite additives, NH4 in biogas residue can be removed. + -N is adsorbed and exchanged into the zeolite, thereby reducing the high concentration of NH4 in the biogas residue. + -N inhibits ultra-high temperature aerobic microorganisms, enabling rapid and efficient conversion of biogas residue.

[0020] 5. Advantages of the closed auger feeding conveyor system of this invention: Compared with traditional open belt conveyors, the closed auger feeding conveyor system not only improves the conveying efficiency of biogas residue, but also reduces energy waste and environmental pollution. It enables the rapid and efficient transport of large quantities of biogas residue to the double-layer fermentation machine system. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0022] Figure 1 This is a schematic diagram of a device for enhancing the aerobic deep composting of wet waste biogas residue, provided in Embodiment 1 of the present invention.

[0023] Reference numerals: 1-First conveyor, 2-Mixer, 3-Second conveyor, 4-Automatic water replenishment device, 5-Horizontal double-layer fermenter, 6-Combined impeller, 7-Third conveyor. Detailed Implementation

[0024] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] like Figure 1 As shown, Embodiment 1 of the present invention provides a device for enhancing the aerobic deep composting of wet waste biogas residue. The device includes a horizontal double-layer fermenter 5, a mixer 2, a first conveyor 1, a second conveyor 3, and a third conveyor 7. One end of the first conveyor 1 is set corresponding to the feed end of the mixer 2. One end of the second conveyor 3 is connected to the mixer 2, and the other end of the second conveyor 3 is connected to the feed end of the horizontal double-layer fermenter 5. The return end of the horizontal double-layer fermenter 5 is connected to the return end of the mixer 2 through the third conveyor 7.

[0028] In this embodiment, an automatic water replenishment device 4 is also provided, which is connected to the feed end of the horizontal double-layer fermenter 5. The automatic water replenishment device 4 solves the problem of large-scale evaporation of moisture in the biogas residue caused by ultra-high temperature and dynamic horizontal mechanical stirring, maintains the moisture content of the biogas residue and the activity of aerobic microorganisms, and accelerates the composting and maturation process of the biogas residue.

[0029] In this embodiment, the first conveyor 1 can be a belt conveyor, while the second conveyor 3 and the third conveyor 7 are both auger conveyors. Compared to traditional open belt conveyors, the enclosed auger feeding conveyor system not only improves the conveying efficiency of biogas residue but also reduces energy waste and environmental pollution. This enables the rapid and efficient transport of large quantities of biogas residue to the double-layer fermentation machine system.

[0030] In this embodiment, the horizontal double-layer fermenter 5 differs from the traditional fermenter. The horizontal double-layer fermenter features an improved stirring device composed of multiple impellers of different shapes centered on the same axis, namely the combined impeller 6 (a turbine-screw-four-blade cyclone impeller combined stirring device). The three types of impellers have a diameter of 0.4m (the ratio of blade diameter to tank diameter is 0.5) and a rotation speed of 50r / min.

[0031] Compared to traditional impellers, the turbine-screw-four-blade cyclone combined impeller of this invention generates eddies, turbulence, and significant shear force through the simultaneous rotation of these three impellers. This allows for rapid and uniform mixing of materials, eliminating gaps between materials and preventing the formation of fluid and solid layers. It can withstand the mixing of large-scale biogas residue, ensuring more uniform and thorough mixing, and accelerating the composting process. This further promotes the application of biogas residue in dynamic aerobic composting.

[0032] For example, the mixing of biogas residue was compared between the impeller before improvement and the improved turbine-screw-four-blade cyclone combined mixing impeller 6. Before the impeller improvement, the maximum load of biogas residue in the 1-compartment horizontal fermenter was 1.2 m³. 3 More than 1.2m 3 The impeller could not perform agitation. However, after using the improved turbine-screw-four-blade cyclone combined agitator impeller, the maximum load of biogas residue in the 1-compartment horizontal fermenter increased to 3m³. 3 The results showed that the impeller improvement significantly increased the maximum loading capacity of biogas residue, further promoting the application of biogas residue in dynamic aerobic composting.

[0033] Example 2

[0034] The embodiments of the present invention set up controls for the effects of water supplementation and no water supplementation on ultra-high temperature aerobic fermentation.

[0035] Based on Example 1, biogas residue and auxiliary materials (mushroom residue) are mixed in a certain proportion. The mixture is then conveyed by belt conveyor 1 into mixer 2, and then by auger conveyor 3 into double-layer fermenter 5. The mixture in double-layer fermenter 5 is repeatedly inoculated with ultra-high temperature aerobic fermentation agent rich in extreme thermophilic microorganisms (YM bacteria, Geobacillus, Thermus, and Calditerricola). The total amount of compound agent added is 2 kg / m³. 3 The mixture was stirred in batches using a combination of turbine-screw-four-blade cyclone impellers 6. All three impellers had a diameter of 0.6 m (blade diameter to tank diameter ratio of 0.6) and a rotation speed of 300 r / min. Part of the material was then fed into the mixer 2 via a auger return conveyor 7 to achieve the ultra-high temperature aerobic fermentation process. In this experiment, one group received a water replenishment system, i.e., water was added during fermentation via an automatic water replenishment system 4, adjusting the moisture content to 55%; the other group did not receive water replenishment. The characteristics of the effects of water replenishment and non-water replenishment on ultra-high temperature aerobic fermentation are compared in Table 1.

[0036] Table 1. Comparison of ultra-high temperature aerobic composting results with and without water replenishment.

[0037]

[0038]

[0039] The results showed that the fermentation cycle of ultra-high temperature aerobic composting with added water was 20-25 days, significantly shorter than that without added water, and the maximum temperature reached over 70℃, much higher than that of ultra-high temperature aerobic composting without added water, although it still did not reach the ideal temperature of over 80℃ for ultra-high temperature aerobic composting. It was also found that the ultra-high temperature fermentation stage (≥70℃) with added water lasted 5-7 days, while the stage without added water (≥60℃) lasted only 3-5 days. This indicates that water supplementation can maintain the heat released by the extreme thermophilic microorganisms through the metabolic decomposition of organic matter, thereby increasing the compost temperature and shortening the fermentation cycle. Furthermore, with added water, we found that the organic matter degradation rate and the reduction effect of biogas residue were much higher than those of ultra-high temperature aerobic composting without added water. Therefore, the addition of a water supplementation system achieves rapid reduction and resource recovery of biogas residue organic solid waste.

[0040] Example 3

[0041] Based on Examples 1 and 2, this example sets up controls to compare the effects of not introducing zeolite additives and introducing zeolite additives on ultra-high temperature aerobic fermentation.

[0042] The zeolite additive group was prepared by mixing zeolite (2mm particle size) with biogas residue and auxiliary material (mushroom residue) in a ratio of 1:10:10. The cation exchange capacity of the zeolite was 150 meq / 100g. The group without zeolite additive was the same as that without zeolite. Subsequent experimental procedures were the same as in Specific Implementation Method 2. The characteristics of ultra-high temperature aerobic composting with and without zeolite additive are compared in Table 2.

[0043] Table 2 Comparison of the effects of zeolite introduction and non-introduction on ultra-high temperature aerobic composting.

[0044]

[0045]

[0046] The results showed that the ultra-high temperature fermentation stage (≥80℃) with zeolite introduction lasted for 7 days, longer than that without zeolite introduction. Furthermore, the temperature of the ultra-high temperature fermentation stage with zeolite introduction reached above 90℃, higher than the highest temperature (above 90℃) of ultra-high temperature aerobic composting without zeolite introduction, indicating that the addition of zeolite reduced NH4 in the biogas residue. + -N content reduces NH4 in biogas residue + -N inhibits the activity of extreme thermophilic microorganisms, allowing them to increase the temperature of the compost pile through the heat released by the decomposition of organic matter, thus achieving the ideal maximum temperature and high-temperature duration, shortening the fermentation cycle, and improving the degradation rate of organic matter and the reduction of biogas residue.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for strengthening the aerobic deep composting of wet garbage marsh residue, based on a device for strengthening the aerobic deep composting of wet garbage marsh residue, characterized in that, The device comprises a horizontal double-layer fermentation machine, a mixer, a first conveyor, a second conveyor and a third conveyor, one end of the first conveyor is arranged corresponding to the feeding end of the mixer, one end of the second conveyor is connected to the mixer, the other end of the second conveyor is connected to the feeding end of the horizontal double-layer fermentation machine, and the return end of the horizontal double-layer fermentation machine is connected to the return end of the mixer through the third conveyor; The method comprises: In the initial stage of aerobic composting, the temperature of the pile is raised to high temperature by repeatedly inoculating the biogas residue with an ultra-high temperature aerobic fermentation agent rich in extreme thermophilic microorganisms. The ultra-high temperature aerobic fermentation agent is a composite microbial agent composed of YM bacteria, Geobacillus, Thermus and Calditerricola microorganisms. The dosage of the composite microbial agent is 1-4 kg / m 3 ; After the whole process of extreme thermophilic bacteria inoculation treatment, the moisture content of the biogas residue in the aerobic composting system is maintained at 35-50% through a preset water supplementing amount; Zeolite is added to the biogas residue in a ratio of 1-1.5:10 in a horizontal double-layer fermentation machine, and the cation exchange capacity of the zeolite is 120-160 meq / 100 g, so as to reduce the high concentration of NH4 + -N in the biogas residue.

2. The method for enhancing the aerobic deep composting of wet garbage biogas residue according to claim 1, characterized in that, Three combined impellers located on the same axis are arranged in the horizontal double-layer fermentation machine.

3. The method for enhancing the aerobic deep composting of wet garbage biogas residue according to claim 2, characterized in that, The combined impeller is a turbine-screw-four-leaf cyclone impeller, the diameters of the three impellers are 0.4-0.6 m, the ratio of the impeller to the tank diameter is 0.5-0.6, and the rotating speed is 50-300 r / min.

4. The method for enhancing the aerobic deep composting of wet garbage biogas residue according to claim 1, characterized in that, A water supplementing device is further arranged, and the water supplementing device is connected to the feeding end of the horizontal double-layer fermentation machine.

5. The method for enhancing the aerobic deep composting of wet waste biogas residue according to claim 1, characterized in that, The second conveyor and the third conveyor are respectively a Jiaolong conveyor and a Jiaolong return conveyor.

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