Garden waste and kitchen waste cooperative treatment system

Abstract

The utility model relates to a cooperative treatment system for garden waste and kitchen waste. The cooperative treatment system comprises a kitchen waste pretreatment system (1), a garden waste pretreatment system (2), a mixed inoculation system (3), a dry anaerobic system (4) and a solid-liquid separation system (5). The kitchen garbage pretreatment system (1) comprises a crusher (1-1), a magnetic separator (1-2) and a screening machine (1-3), and is used for crushing kitchen garbage for pulping and separating organic matters and inorganic matters; the garden waste pretreatment system (2) comprises a crushing unit (2-1) and an acid and enzyme treatment unit (2-2), and is used for crushing garden waste into proper particle sizes and carrying out acid and enzyme combined pretreatment; the mixed inoculation system (3) is used for mixing the pretreated kitchen waste slurry and the pretreated garden waste slurry and carrying out heating inoculation and material blending on the mixed slurry; the dry anaerobic system (4) is used for fermenting the slurry to produce biogas; and the solid-liquid separation system (5) is used for separating the fermentation slurry into biogas residues and biogas slurry. Through cooperative treatment of garden waste and kitchen waste, the biogas yield is increased, and the system is simple in technological process and high in stability.

Description

Technical Field

[0001] The utility model belongs to the technical field of anaerobic fermentation of organic solid waste, and in particular relates to a system for coordinating treatment of garden waste and kitchen waste. Background Art

[0002] With the advancement of garbage classification and the gradual improvement of classification level, more and more examples of anaerobic fermentation of organic solid waste biogas projects are being applied. Common organic solid waste includes: kitchen waste, garden waste, fruit and vegetable waste, livestock and poultry manure and crop straw, etc. After anaerobic fermentation, organic solid waste will produce biogas bioenergy, effectively alleviating the contradiction between energy supply and demand and improving the energy structure. Therefore, anaerobic fermentation biogas project is an important way to utilize organic solid waste resources.

[0003] There are two main methods for anaerobic fermentation of organic solid waste: wet anaerobic and dry anaerobic. Wet anaerobic is suitable for organic solid waste with a solid content of 8%-15%, and is widely used in engineering, but it has high requirements for pretreatment capacity, slurry quality, sand and impurity content, and is sensitive to load shock. Dry anaerobic is suitable for organic solid waste with a higher solid content (15%-40%), has strong load shock resistance, and has low requirements for material pretreatment, but the investment cost of dry anaerobic equipment is relatively high.

[0004] Affected by economic level, dietary structure, waste classification level and supporting facilities construction, there are certain differences in the classified collection and transportation of kitchen waste in various regions, but in general, the solid content of kitchen waste is relatively high, ranging from 15% to 35%, and the C / N ratio is 15 to 30. Due to the high solid content of kitchen waste, if the wet anaerobic method is used to reduce the solid content, a large amount of water will be consumed, but the amount of biogas slurry treatment will increase, resulting in a waste of water resources. Therefore, the dry anaerobic method is used to ferment high-solid kitchen waste. Garden waste is rich in carbon, low in nitrogen, and has a high solid content (TS 40%-60%). In particular, the C / N ratio of plant branches is as high as 56.5. Garden waste is usually treated by landfill, incineration, pyrolysis, composting and anaerobic fermentation. Landfill and incineration methods will cause environmental pollution and waste of resources, and pyrolysis is prone to secondary pollution. Composting can turn garden waste resources into organic fertilizer, but there are problems such as long time for complete decomposition, poor fertilizer efficiency, and limited application of organic fertilizer. Therefore, a dry anaerobic system that can tolerate high-solid materials can be used to treat garden waste.

[0005] The coordinated treatment of kitchen waste and garden waste can not only adjust the solid content and C / N ratio of the material, effectively solve the system instability problem caused by material fluctuation and accumulation of volatile fatty acids, but also significantly improve the anaerobic digestion efficiency and biogas production. The patent number is: CN201810140063.5, and the patent name is: A method for the coordinated disposal of kitchen waste and green waste, using a two-phase wet anaerobic method to treat kitchen waste and green waste generated in residential areas. However, due to the high solid content of the material, water with a mass ratio of 1:1-3:1 to kitchen waste needs to be added during pulping for dilution, which increases unnecessary water resource use and biogas slurry treatment. At the same time, ultrasound and high-temperature hot wet methods are used to treat garden waste, and the equipment investment and operating costs are high. Utility Model Content

[0006] The purpose of the utility model is to provide a system for coordinating the treatment of garden waste and kitchen waste, so as to solve the problems existing in the background technology.

[0007] In order to solve the technical problem, the utility model provides a system for coordinating the treatment of garden waste and kitchen waste, which is characterized by comprising:

[0008] A kitchen waste pretreatment system (1), the kitchen waste pretreatment system (1) comprising a crusher (1-1), a magnetic separator (1-2), and a screening machine (1-3) connected in sequence, the crusher (1-1) being used to crush the kitchen waste and prepare a slurry with a particle size of ≤80 mm, the magnetic separator (1-2) being used to recover ferrous metals in the kitchen waste, and the screening machine (1-3) being used to sort out coarse materials with a particle size of ≥60 mm and light and flexible debris such as plastics and textiles in the kitchen waste.

[0009] A garden waste pretreatment system (2), the garden waste pretreatment system (2) comprising a crushing unit (2-1) and an acid + enzyme treatment unit (2-2), the crushing unit (2-1) being used to crush the garden waste to a particle size of ≤80 mm, the acid + enzyme treatment unit (2-2) being used to subject the crushed garden waste to acetic acid soaking treatment and laccase biotreatment, thereby accelerating the degradation of lignocellulose in the garden waste.

[0010] A mixing and inoculation system (3) is used to mix the pre-treated kitchen waste slurry and the garden waste slurry, heat the mixed slurry, mix the materials, and adjust the TS and C / N range of the mixed slurry. The feed inlet of the mixing and inoculation system (3) is connected to the organic matter discharge port of the screening machine (1-3) and the discharge port of the enzyme treatment unit (2-3).

[0011] A dry anaerobic system (4) is used to ferment the mixed slurry to produce biogas, and its feed inlet is connected to the discharge outlet of the mixed inoculation system (3).

[0012] A solid-liquid separation system (5) is used to separate the fermentation slurry into biogas residue and biogas liquid, and its feed inlet is connected to the discharge outlet of the dry anaerobic system (4).

[0013] Furthermore, the screening screw inside the screening machine (1-3) is arranged at an angle, and a trash can or an impurity conveying screw for collecting impurities is placed at the bottom of the inorganic impurity discharge port.

[0014] Furthermore, the crushing unit (2-1) comprises at least one double-shaft crusher.

[0015] Furthermore, the acid+enzyme combined treatment unit (2-2) and the mixed inoculation system (3) are both equipped with a central stirring device to ensure uniformity of the materials, and are both equipped with a steam coil jacket to achieve temperature control.

[0016] Furthermore, the dry anaerobic system (4) is a horizontal anaerobic system, equipped with a dual heating system of tank bottom heating and heating gun heating, and the agitator is a long-axis agitator to ensure that the materials are fully mixed.

[0017] Furthermore, the solid-liquid separation system (5) comprises at least one extrusion dehydrator and one centrifugal dehydrator to ensure that the dehydrated biogas residue has a high solid content. The biogas slurry discharge port of the solid-liquid separation system (5) is connected to a pipeline provided with a flow control valve, and is connected to the liquid phase feed port of the mixed inoculation system (3) to achieve the effect of biogas slurry reflux inoculation. The biogas residue discharge port of the solid-liquid separation system (5) is connected to the solid phase feed port of the mixed inoculation system (3) through a weighing screw. When the output of garden waste raw materials is insufficient or fluctuates greatly, the biogas residue is recycled to the mixed inoculation system (3) for the preparation of anaerobic materials.

[0018] Beneficial effects:

[0019] (1) The utility model pre-treats garden waste by crushing and acid + enzyme combined treatment system, which can accelerate the degradation of lignocellulose in garden waste. At the same time, by reflux inoculation of biogas slurry, the fermentation cycle is shortened and the biogas production is increased.

[0020] (2) This system can effectively avoid the stratification phenomenon of kitchen waste in the dry anaerobic system, adjust the C / N ratio and solid content of the raw materials, and improve the operating stability and gas production rate of the dry anaerobic system.

[0021] (3) By reusing biogas residue to adjust the C / N ratio and solid content of the mixture of kitchen waste and garden waste, the problem of material output and property fluctuations caused by seasonal pruning of garden waste can be effectively addressed. In addition, the cost of transporting and disposing of biogas residue can be reduced, project benefits can be increased, and the resource utilization rate of kitchen waste and garden waste can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 The utility model is a flow chart of a system for coordinating the treatment of garden waste and kitchen waste.

[0024] In the figure, 1-kitchen waste pretreatment system, 1-1 crusher, 1-2 magnetic separator, 1-3 screening machine, 2-garden waste pretreatment system, 2-1 crushing unit, 2-2 acid + enzyme treatment unit, 3-mixed inoculation system, 4-dry anaerobic system, 5-solid-liquid separation system. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0026] See also Figure 1 The utility model provides a technical solution:

[0027] like Figure 1 As shown, a system for co-processing kitchen waste and garden waste includes:

[0028] A kitchen waste pretreatment system (1), the kitchen waste pretreatment system (1) comprising a crusher (1-1), a magnetic separator (1-2), and a screening machine (1-3) connected in sequence, the crusher (1-1) being used to crush the kitchen waste and prepare a slurry with a particle size of ≤80 mm, the magnetic separator (1-2) being used to recover ferrous metals in the kitchen waste, and the screening machine (1-3) being used to sort out coarse materials with a particle size of ≥60 mm and light and flexible debris such as plastics and textiles in the kitchen waste.

[0029] A garden waste pretreatment system (2), the garden waste pretreatment system (2) comprising a crushing unit (2-1) and an acid + enzyme treatment unit (2-2), the crushing unit (2-1) being used to crush the garden waste to a particle size of ≤80 mm, the acid + enzyme treatment unit (2-2) being used to subject the crushed garden waste to acetic acid soaking treatment and laccase biotreatment, thereby accelerating the degradation of lignocellulose in the garden waste.

[0030] A mixing and inoculation system (3) is used to mix the pre-treated kitchen waste slurry and the garden waste slurry, heat the mixed slurry, mix the materials, and adjust the TS and C / N range of the mixed slurry. The feed inlet of the mixing and inoculation system (3) is connected to the organic matter discharge port of the screening machine (1-3) and the discharge port of the enzyme treatment unit (2-3).

[0031] A dry anaerobic system (4) is used to ferment the mixed slurry to produce biogas, and its feed inlet is connected to the discharge outlet of the mixed inoculation system (3).

[0032] A solid-liquid separation system (5) is used to separate the fermentation slurry into biogas residue and biogas liquid, and its feed inlet is connected to the discharge outlet of the dry anaerobic system (4).

[0033] The screening screw inside the screening machine (1-3) is arranged at an angle, and a trash can or an impurity conveying screw for collecting impurities is placed at the bottom of the inorganic impurity discharge port.

[0034] The crushing unit (2-1) comprises at least one double-shaft crusher.

[0035] The acid+enzyme combined treatment unit (2-2) and the mixed inoculation system (3) are both equipped with a central stirring device to ensure uniformity of the materials, and are both equipped with a steam coil jacket to achieve temperature control.

[0036] The dry anaerobic system (4) is a horizontal anaerobic system, equipped with a dual heating system of tank bottom heating and heating gun heating, and the agitator is a long-axis agitator to ensure that the materials are fully mixed.

[0037] The solid-liquid separation system (5) comprises at least one extrusion dehydrator and one centrifugal dehydrator to ensure that the dehydrated biogas residue has a high solid content. The biogas slurry discharge port of the solid-liquid separation system (5) is connected to a pipeline provided with a flow control valve, and is connected to the liquid phase feed port of the mixed inoculation system (3) to achieve the effect of biogas slurry reflux inoculation. The biogas residue discharge port of the solid-liquid separation system (5) is connected to the solid phase feed port of the mixed inoculation system (3) through a weighing screw. When the output of garden waste raw materials is insufficient or fluctuates greatly, the biogas residue is recycled to the mixed inoculation system (3) for the preparation of anaerobic materials.

[0038] Through the above technical scheme, when the kitchen waste enters the kitchen waste pretreatment system, it is crushed into materials with a particle size of ≤80mm by the crusher, and then enters the magnetic separator to sort out the mixed iron for recycling, and then enters the screening machine. Through low-speed rotary screening, coarse materials with a particle size of ≥60mm and light and flexible debris such as plastics and textiles in the kitchen waste are screened out. The internal screening spiral is tilted, and the screened inorganic impurities fall to the impurity discharge port at the lower end, fall into the trash can placed at the bottom of the discharge port, or fall into the impurity conveying spiral, and are finally transported out for incineration.

[0039] Garden waste enters the garden waste pretreatment system, is crushed into materials with a particle size of ≤80mm by a double-shaft crusher, and enters the acetic acid and laccase joint treatment unit. First, it is soaked in acetic acid of appropriate concentration at a suitable solid-liquid ratio and temperature for a period of time, and then a certain concentration of industrial-grade laccase is added to the slurry. The pH and temperature are adjusted to the optimal range and reacted for a period of time.

[0040] The pre-treated kitchen waste and garden waste are sent to the mixed inoculation system in a certain proportion. According to the properties of the mixed materials, the TS and C / N of the returned biogas slurry mixture are added in appropriate amounts, and the temperature is adjusted to a suitable inoculation temperature. After stirring until the materials are evenly mixed, they are pumped into the dry anaerobic fermentation system for fermentation and biogas production. After 27-30 days of fermentation, the materials enter the solid-liquid separation system, where they are first extruded and dehydrated, and then the solid phase after extrusion and dehydration is centrifuged and finally separated into biogas residue and biogas slurry. In summer, when the garden waste is mainly grass and leaves and is seldom pruned, the solid content of the garden waste is low and the output is insufficient. Part of the biogas residue can be reused in the mixed inoculation system to supplement the shortage of garden waste.

[0041] The above is only a preferred embodiment of the utility model. It should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be protected by the claims attached to the utility model.

Claims

1. A system for coordinating the treatment of garden waste and kitchen waste, characterized in that: include: A kitchen waste pretreatment system (1), the kitchen waste pretreatment system (1) comprising a crusher (1-1), a magnetic separator (1-2), and a sieving machine (1-3) connected in sequence, the crusher (1-1) being used to crush the kitchen waste and prepare a slurry with a particle size of ≤80 mm, the magnetic separator (1-2) being used to recover ferrous metals in the kitchen waste, and the sieving machine (1-3) being used to separate coarse materials with a particle size of ≥60 mm in the kitchen waste; A garden waste pretreatment system (2), the garden waste pretreatment system (2) comprising a crushing unit (2-1) and an acid + enzyme treatment unit (2-2), the crushing unit (2-1) being used to crush the garden waste to a particle size of ≤80 mm, the acid + enzyme treatment unit (2-2) being used to perform acetic acid soaking treatment and laccase biotreatment on the crushed garden waste, thereby accelerating the degradation of lignocellulose in the garden waste; A mixed inoculation system (3), the mixed inoculation system (3) is used to mix the pre-treated kitchen waste slurry and the garden waste slurry, heat the mixed slurry, mix the materials, and adjust the TS and C / N range of the mixed slurry. The feed inlet of the mixed inoculation system (3) is connected to the organic matter discharge port of the screening machine (1-3) and the discharge port of the enzyme treatment unit (2-2); A dry anaerobic system (4), the dry anaerobic system (4) is used to ferment the mixed slurry to produce biogas, and its feed inlet is connected to the discharge outlet of the mixed inoculation system (3); A solid-liquid separation system (5) is used to separate the fermentation slurry into biogas residue and biogas liquid, and its feed inlet is connected to the discharge outlet of the dry anaerobic system (4).

2. A system for coordinating the treatment of garden waste and kitchen waste according to claim 1, characterized in that The screening screw inside the screening machine (1-3) is arranged at an angle, and a trash can or an impurity conveying screw for collecting impurities is placed at the bottom of the inorganic impurity discharge port.

3. A system for coordinating the treatment of garden waste and kitchen waste according to claim 1, characterized in that The crushing unit (2-1) comprises at least one double-shaft crusher.

4. The system for coordinating the treatment of garden waste and kitchen waste according to claim 1, characterized in that The acid+enzyme combined treatment unit (2-2) and the mixed inoculation system (3) are both equipped with a central stirring device to ensure uniformity of the materials, and are both equipped with a steam coil jacket to achieve temperature control.

5. The system for coordinating the treatment of garden waste and kitchen waste according to claim 1, characterized in that The dry anaerobic system (4) is a horizontal anaerobic system, equipped with a dual heating system of tank bottom heating and heating gun heating, and the agitator is a long-axis agitator to ensure that the materials are fully mixed.

6. The system for coordinating the treatment of garden waste and kitchen waste according to claim 1, characterized in that The solid-liquid separation system (5) comprises at least one extrusion dehydrator and one centrifugal dehydrator, so as to ensure that the dehydrated biogas residue has a high solid content; the biogas liquid discharge port of the solid-liquid separation system (5) is connected to a pipeline provided with a flow control valve, and is connected to the liquid phase feed port of the mixed inoculation system (3), so as to achieve the effect of biogas liquid reflux inoculation; the biogas residue discharge port of the solid-liquid separation system (5) is connected to the solid phase feed port of the mixed inoculation system (3) through a weighing screw, and when the output of the garden waste raw material is insufficient or fluctuates greatly, the biogas residue is recycled to the mixed inoculation system (3) for preparing anaerobic materials.

Images