A sludge biological drying-pyrolysis integrated device and method

Abstract

The present invention discloses a sludge biological drying-pyrolysis integrated device and method, which mainly includes a biological drying reactor (including a high-temperature start-up bin and a micro-pressure aeration bin), a deodorizing device, a granulator, a pyrolysis furnace, a combustion furnace, a boiler, etc. After the sludge is treated by biological drying and granulation, it is transported to the pyrolysis furnace, and the pyrolysis carbon produced by pyrolysis is cooled and stored, while the high-temperature flue gas produced by the combustion of pyrolysis gas enters the boiler and is converted into hot water or hot steam to provide energy supply for the biological drying reactor. The biological drying of this device is coupled with the internal heat pyrolysis, and the biological drying reduces the high energy consumption, high cost and high pollution of the sludge thermal drying process; pyrolysis is used instead of the incineration process to reduce the production of harmful substances such as dioxins, and the clean combustible gas and pyrolysis carbon produced by pyrolysis improve the resource utilization of sludge and the cleanliness of the treatment process. The biological drying tail gas is discharged after harmless treatment, which provides a low-pollution, low-energy consumption and low-economy technical route for sludge treatment and disposal.

Description

Technical Field

[0001] The invention belongs to the technical field of high-water-content organic solid waste energy conversion, and particularly relates to a sludge biological drying-pyrolysis integrated device and method. Background Art

[0002] In recent years, in contrast to the rapid development of sewage treatment, the development of sludge treatment and disposal has been very slow, and the effective disposal rate of sludge is low. With the increase in the production of stored sludge, the environmental and other problems caused have received more and more attention. According to the survey results, about 2 / 3 of the sludge is currently landfilled, 1 / 5 is transported and randomly piled up, and the proportion of incineration and resource utilization is relatively small. Therefore, the treatment of stored sludge is imminent. Since the properties of stored sludge and high water content affect its further treatment and disposal, the use of drying technology to first dehydrate and then recycle the dried sludge into resources and energy is one of the current economically feasible methods for stored sludge.

[0003] Traditional physical drying has high energy consumption, while chemical drying is contrary to the concept of solid waste reduction and is prone to produce toxic and harmful tail gas. Biological drying technology mainly uses the bioheat generated by aerobic microorganisms to degrade organic matter to remove moisture from sludge. It is an economical and environmentally friendly drying method. At the same time, pyrolysis technology can convert organic matter in solid waste into clean liquid or gaseous fuels, and this process can inhibit the production of toxic and harmful gases such as dioxins. It is considered to be a clean thermal treatment method to replace incineration. At present, biological drying is mostly carried out as a single biological drying, and pyrolysis is mainly combined with dried materials as raw materials or other drying forms. There is a lack of low-energy consumption, environmentally friendly biological drying and clean, resource-based pyrolysis process combinations, as well as integrated engineering applications such as combined matching flue gas purification. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art and promote the engineering application and promotion of the integrated device of biological drying process and pyrolysis process, the purpose of the present invention is to provide a sludge biological drying-pyrolysis integrated device and method, firstly, the stored sludge and the conditioning agent are fully mixed in the premixing tank, and then enter the biological drying reactor for biological drying, the dried organic material or the mixed granulation with the biomass enters the pyrolysis furnace for pyrolysis, the high-temperature flue gas generated by the combustion of the pyrolysis gas is used as the energy required for biological drying, and the drying tail gas discharged from the micro-negative pressure bin of the biological drying reactor is deodorized and discharged in compliance with the standards. Thereby, an effective combination of biological drying and pyrolysis of stored sludge is achieved, and low energy consumption, cleanness and resource utilization of water-containing organic solid waste treatment and disposal are achieved.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A sludge biological drying-pyrolysis integrated device comprises a biological drying reactor and a premixing tank 1 for storing sludge and a conditioning agent therein for substrate conditioning, wherein the substrate outlet of the premixing tank 1 is connected to the material inlet of the biological drying reactor, the material outlet of the biological drying reactor is connected to the material inlet of a granulator 5, the material outlet of the granulator 5 is connected to the material inlet of a pyrolysis furnace 6, the material outlet of the pyrolysis furnace 6 is connected to a cooling conveyor 10, the gas outlet of the pyrolysis furnace 6 is connected to the inlet of a combustion furnace 7, the outlet of the combustion furnace 7 is connected to the flue gas inlet of a boiler 9, and the heat medium outlet of the boiler 9 is connected to the heat medium inlet of the biological drying reactor.

[0007] Preferably, a deodorization device 4 is provided at the gas outlet of the bio-drying reactor.

[0008] Preferably, the biological drying reactor includes a high-temperature starting bin 2 and a micro-pressure aeration bin 3, the substrate outlet of the premixing tank 1 is connected to the material inlet of the high-temperature starting bin 2, the material outlet of the high-temperature starting bin 2 is connected to the material inlet of the micro-pressure aeration bin 3, and the material outlet of the micro-pressure aeration bin 3 is connected to the material inlet of the granulator 5.

[0009] The present invention also provides a sludge biological drying-pyrolysis integrated method based on the sludge biological drying-pyrolysis integrated device, comprising the following steps:

[0010] a. Fully mix the stored sludge and the conditioning agent in proportion in the premixing tank 1;

[0011] b. transporting the organic solid waste prepared in step a to a biological drying reactor to dry the organic solid waste;

[0012] c. The dried material produced in step b is conveyed to the granulator 5 for granulation, and then conveyed to the pyrolysis furnace 6. The pyrolytic char produced by pyrolysis is output through the cooling conveyor 10 for standby use, and the pyrolysis gas produced by pyrolysis directly enters the combustion furnace 7. The high-temperature flue gas produced by combustion enters the boiler 9 and is converted into hot water or hot steam as energy supply for the biological drying reactor.

[0013] Preferably, the conditioning agent is kitchen waste and straw. The design principle is that the kitchen waste substrate is rich in protein, fat and sugar, and the presence of macromolecular nutrients will cause the microorganisms in the entire system to proliferate rapidly and reach the logarithmic phase. The presence of straw will reduce the density of the entire substrate system, which is conducive to the full mixing and aeration process of the substrate.

[0014] Preferably, the biological drying reactor includes a high-temperature starting chamber 2 and a micro-pressure aeration chamber 3. The organic solid waste material is first subjected to rapid microbial proliferation and expansion in the high-temperature starting chamber 2 to promote the rapid degradation of organic macromolecules in the substrate material into small molecules, and then transported to the micro-pressure aeration chamber 3. Micro-negative pressure is used to inhibit the biological process to maintain it in a logarithmic stable period, and negative pressure aeration is used to draw the drying tail gas to the deodorization device 4 for discharge after harmlessness.

[0015] Preferably, the temperature of the high-temperature starting bin 2 is controlled at 55-60° C. The design principle is that the rapid heating of the substrate causes the entire pile to quickly enter the high-temperature period, thereby shortening the fermentation cycle.

[0016] The micro-pressure aeration chamber 3 is a micro-negative pressure aeration with a pressure range of -5mmAp to -10mmAp. The design principles are twofold: first, the pressure causes the metabolism process of the microorganisms to be controlled, so that it can be maintained in a logarithmic stable period for a long time, and the substrate degradation effect is better and more sufficient; second, the negative pressure exhaust can concentrate the odor generated by the fermentation into the deodorization device 4 during aeration.

[0017] Preferably, in the granulator 5, the dried material is mixed with biomass having a particle size of 2-8 mm for granulation.

[0018] Preferably, the pyrolysis furnace 6 is an endothermic pyrolysis furnace, an exothermic pyrolysis furnace or other pyrolysis gasification processes, the temperature inside the pyrolysis furnace 6 is controlled at 400-700°C, and the combustion temperature of the combustion furnace 7 is controlled at 750-1100°C.

[0019] Preferably, the cooling conveyor 10 is a device that adopts two cooling methods: direct water spray gasification and indirect water jacket cooling.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention couples biological drying with internal heat pyrolysis. Biological drying reduces the high energy consumption, high cost and high pollution in the thermal drying process of sludge. Pyrolysis is used instead of incineration process to reduce the generation of harmful substances such as dioxins. The clean combustible gas and pyrolytic carbon generated by pyrolysis improve the resource utilization of sludge and the cleanliness of the treatment process. The exhaust gas from biological drying is harmlessly treated and then discharged, providing a low-pollution, low-energy consumption and low-economy technical route for sludge treatment and disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the present invention. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0024] The present invention provides an integrated device and method for biological drying and pyrolysis of stored sludge. The specific technical methods and devices of the present invention are described in detail and completely in conjunction with the accompanying drawings and specific embodiments. The specific embodiments described are only some examples of the present invention, not all examples. All other examples obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] Figure 1 The schematic diagram of the biological drying-pyrolysis integrated device for storing sludge of the present invention is shown. As shown in the figure, the present invention includes a premixing tank 1, a high temperature starting chamber 2, a micro-pressure aeration chamber 3, a deodorizing device 4, a granulator 5, a pyrolysis furnace 6, a combustion furnace 7, an oil and gas burner 8, a boiler 9 and a cooling conveyor 10.

[0026] The stored sludge is conditioned with a conditioner in the premixing tank 1, and then transported to the biological drying reactor, that is, enters the high-temperature starting bin 2, and then the organic solid waste material is dried through the micro-pressure aeration bin 3, and then transported to the granulator 5 for granulation, and then transported to the pyrolysis furnace 6. The pyrolytic carbon produced by pyrolysis is output through the cooling conveyor 9 and stored for standby use, while the pyrolysis gas produced by pyrolysis directly enters the combustion furnace 7. The high-temperature flue gas produced by combustion is converted into hot water or hot steam through the boiler as energy supply for the biological drying reactors 2 and 3. The tail gas of the biological drying reaction is discharged after being rendered harmless by the deodorization device 4.

[0027] The storage sludge conditioner is kitchen waste and straw. The design principle is that the kitchen waste substrate is rich in protein, fat and sugar. The presence of macromolecular nutrients will cause the microorganisms in the whole system to proliferate rapidly and reach the logarithmic phase. The presence of straw will reduce the density of the whole substrate system, which is conducive to the full mixing and aeration process of the substrate.

[0028] The biological drying reactor is composed of a high-temperature starting chamber and a micro-pressure aeration chamber.

[0029] The high temperature starting bin is set at a temperature of 55-60°C. The design principle is that the rapid heating of the substrate causes the entire pile to quickly enter a high temperature period, thereby shortening the fermentation cycle.

[0030] The micro-pressure aeration chamber is a micro-negative pressure aeration chamber, and its design principles are twofold: first, the pressure causes the metabolic process of microorganisms to be controlled, so that it can be maintained in a logarithmic stable period for a long time, and the substrate degradation effect is better and more sufficient; second, the negative pressure exhaust system can concentrate the odor generated by fermentation into the deodorization device during aeration.

[0031] The dried material can be mixed with biomass with a particle size of 2-8 mm to form granules.

[0032] The pyrolysis furnace is an internal heating pyrolysis furnace, an external heating pyrolysis furnace or other pyrolysis gasification processes, and the temperature in the pyrolysis furnace is controlled at 400-700°C.

[0033] The cooling conveyor is a device that adopts two cooling methods: direct water spray gasification and indirect water jacket cooling.

[0034] The combustion temperature of the combustion furnace is controlled at 750-1100°C.

[0035] The biological drying-pyrolysis integrated device and method for stored sludge comprises the following steps:

[0036] a. The stored sludge and the conditioning agent are fully mixed in proportion in the premixing tank 1. The conditioning agent is kitchen waste and straw.

[0037] b. The prepared materials in step a are transported to the biological drying reactor, where they are first rapidly multiplied and expanded in the high-temperature start-up chamber 2 to promote the rapid degradation of organic macromolecules in the substrate material into small molecules, and then transported to the micro-pressure aeration chamber 3. The micro-negative pressure in this chamber causes the biological process to be slightly inhibited, so that it is maintained in a logarithmic stable period. Negative pressure aeration draws the drying tail gas to the deodorization device 4 for harmless discharge.

[0038] c. The dried material produced in step b is conveyed to the granulator 5 for granulation, and then conveyed to the pyrolysis furnace 6. The pyrolytic carbon produced by pyrolysis is output through the cooling conveyor 9 for standby use, and the pyrolysis gas produced by pyrolysis directly enters the combustion furnace 7. The high-temperature flue gas produced by combustion enters the boiler 9 and is converted into hot water or hot steam as energy supply for the biological drying reactor. At the same time, the oil and gas burner 8 can also be used as an additional energy supply for the boiler 9 to avoid insufficient energy of the high-temperature flue gas generated by the combustion furnace 7.

[0039] By using the biological drying process of the present invention, the initial moisture content of sludge greater than 70% can be reduced to less than 15% within 7 days, and in the pyrolysis process section, the charcoal yield is 50%, that is, 100 kg of sludge produces 50 kg of charcoal.

Claims

1. A sludge biological drying-pyrolysis integrated method, which is implemented based on a sludge biological drying-pyrolysis integrated device, wherein the sludge biological drying-pyrolysis integrated device comprises a biological drying reactor and a premixing tank (1) for allowing stored sludge and a conditioning agent to perform substrate conditioning therein, wherein a substrate outlet of the premixing tank (1) is connected to a material inlet of the biological drying reactor, the material outlet of the biological drying reactor is connected to a material inlet of a granulator (5), the material outlet of the granulator (5) is connected to a material inlet of a pyrolysis furnace (6), the material outlet of the pyrolysis furnace (6) is connected to a cooling conveyor (10), the gas outlet of the pyrolysis furnace (6) is connected to an inlet of a combustion furnace (7), the outlet of the combustion furnace (7) is connected to a flue gas inlet of a boiler (9), and the heat medium outlet of the boiler (9) is connected to the heat medium inlet of the biological drying reactor; The biological drying reactor comprises a high-temperature starting bin (2) and a micro-pressure aeration bin (3); the substrate outlet of the premixing tank (1) is connected to the material inlet of the high-temperature starting bin (2); the material outlet of the high-temperature starting bin (2) is connected to the material inlet of the micro-pressure aeration bin (3); the material outlet of the micro-pressure aeration bin (3) is connected to the material inlet of a granulator (5); and a deodorizing device (4) is provided at the gas outlet of the biological drying reactor; It is characterized in that The steps include: a. Fully mix the stored sludge and the conditioning agent in a premixing tank (1) according to the proportion; b. The organic solid waste prepared in step a is transported to a biological drying reactor to dry the organic solid waste; the biological drying reactor comprises a high-temperature starting chamber (2) and a micro-pressure aeration chamber (3); the organic solid waste is firstly subjected to rapid microbial proliferation and propagation in the high-temperature starting chamber (2) to promote rapid degradation of organic macromolecules in the substrate material into small molecules, and then transported to the micro-pressure aeration chamber (3) to inhibit the biological process by micro-negative pressure to maintain it in a logarithmic stable period, and to use negative pressure aeration to draw the drying tail gas to a deodorization device (4) for harmless discharge; the temperature of the high-temperature starting chamber (2) is controlled at 55-60° C., and the micro-pressure aeration chamber (3) is a micro-negative pressure aeration chamber with a pressure range of -5 mmAp to -10 mmAp; c. The dried material produced in step b is transported to a granulator (5) for granulation, and then transported to a pyrolysis furnace (6). The pyrolysis char produced by pyrolysis is output through a cooling conveyor (10) for standby use, and the pyrolysis gas produced by pyrolysis directly enters a combustion furnace (7). The high-temperature flue gas produced by combustion enters a boiler (9) and is converted into hot water or hot steam as energy supply for a biological drying reactor. In the granulator (5), the dried material is mixed with biomass having a particle size of 2-8 mm for granulation. The pyrolysis furnace (6) is an endothermic pyrolysis, an exothermic pyrolysis or other pyrolysis gasification process. The temperature inside the pyrolysis furnace (6) is controlled at 400-700° C., and the combustion temperature of the combustion furnace (7) is controlled at 750-1100° C.

2. The sludge biological drying-pyrolysis integrated method according to claim 1, characterized in that: The conditioning agents are kitchen waste and straw.

3. The sludge biological drying-pyrolysis integrated method according to claim 1, characterized in that: The cooling conveyor (10) is a device that adopts two cooling methods: direct water spray gasification and indirect water jacket cooling.

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