CN114484439A - Kitchen waste and household waste collaborative pyrolysis treatment system and method - Google Patents

Abstract

The invention discloses a system and method for co-pyrolysis treatment of kitchen waste and domestic waste, including a kitchen waste pretreatment system, a domestic waste and a kitchen waste mixing system, a sewage treatment device, a waste pyrolysis system, a waste heat utilization system, a flue gas Purification system; after pretreatment of kitchen waste, it is mixed with domestic waste and then pyrolyzed and gasified, and the gas combustion of pyrolysis and gasification is used as output energy. At the same time, all solid waste, concentrate and crude oil generated in each process are Pyrolysis and gasification are carried out, and all kinds of harmful liquids and gases produced are harmlessly treated and discharged up to the standard, and low-grade heat energy is recovered and utilized as heat energy for system operation through heat exchange; through energy cascade utilization, energy utilization is maximized, emission reduction.

Description

A system and method for co-pyrolysis treatment of kitchen waste and domestic waste

technical field

The invention belongs to the field of waste resource utilization and harmless treatment, and in particular relates to a collaborative pyrolysis treatment system for kitchen waste and domestic waste and a treatment method.

Background technique

Garbage disposal is attracting more and more attention. The conventional treatment technologies for kitchen waste include feed, composting, anaerobic fermentation, etc. The conventional treatment technologies for domestic waste include sanitary landfill, incineration power generation, pyrolysis and gasification, etc. Among the above technologies applicable to the treatment of kitchen waste and domestic waste, due to the different types of waste, the treatment requirements are different, and they are usually used alone, and most of them deal with a single type of waste.

In the face of the increasingly tight urban and rural land use indicators and the problems of single waste raw material treatment, the waste treatment is gradually moving towards the development path of intensive and collaborative processing. The problems and shortcomings of the current solid waste treatment field are widely concerned.

Specifically for the most common kitchen waste and domestic waste in residents' daily life, how to realize the co-processing of the two wastes, improve the integration of the treatment system, save land resources, reduce project investment, reduce pollutant emissions, and improve the efficiency of waste treatment to achieve Building a project to achieve the purpose of various waste treatment is the current key research direction in the field of kitchen waste and domestic waste treatment.

SUMMARY OF THE INVENTION

The moisture content of kitchen waste and domestic waste is different. Statistics show that the moisture content of kitchen waste is nearly double or even higher than that of domestic waste. The high water content leads to the problem that the energy consumption of the treatment process is too high and the treatment time increases. The purpose of the present invention is to provide a system and method for the co-processing of kitchen waste and domestic waste, so that when the kitchen waste and domestic waste are mixed, the moisture content of the kitchen waste is close to that of the domestic waste, thereby reducing the energy consumption for processing.

In order to achieve the above purpose, the technical solution provided by the present invention is a collaborative pyrolysis treatment system for kitchen waste and domestic waste, including a kitchen waste pretreatment system, a domestic waste and a kitchen waste mixing system, a sewage treatment device, a waste pyrolysis system, Waste heat utilization system, flue gas purification system;

The kitchen waste pretreatment system separates the kitchen waste from solid and liquid, and sends the solid phase kitchen waste material to the domestic waste and kitchen waste mixing system to mix with the domestic waste, and the liquid phase material is processed by oil extraction;

The domestic waste and kitchen waste mixing system mixes the domestic waste and the pretreated kitchen waste;

The waste pyrolysis system pyrolyzes and gasifies the mixed domestic waste and kitchen waste, the oil-phase material treated by oil extraction, and the concentrate of the leachate in the mixed system of domestic waste and kitchen waste, and burns the generated gas. The generated electrical or thermal energy is utilized as an energy output;

The waste heat utilization system exchanges the heat of the high temperature flue gas after gas combustion with the normal temperature air at the mixing system of domestic waste and kitchen waste and feeds it back to the pyrolysis treatment system;

The sewage treatment device conducts harmless treatment of the concentrated supernatant of the leachate of the domestic waste and kitchen waste mixing system and the water-phase material after the oil extraction of the kitchen waste;

Flue gas purification system purification The flue gas generated by the waste pyrolysis system is purified to meet the standards such as dust removal, dechlorination, desulfurization, destocking, and dioxin removal.

Preferably, the food waste pretreatment system includes a receiving device, a crushing device, a first solid-liquid separation device, a second solid-liquid separation device, an oil extraction device, and a food waste conveying device;

The receiving device sends the received kitchen waste to the crushing device for crushing;

The first solid-liquid separation device dehydrates the crushed kitchen waste to obtain slurry and solid kitchen waste;

The second solid-liquid separation device further separates the dehydrated slurry from solid-liquid to obtain solid kitchen waste and liquid-phase materials;

The oil-lifting device performs oil-lifting treatment on the liquid-phase material after solid-liquid separation, so as to separate the oil and water to obtain the oil-phase material and the water-phase material, and the water-phase material is sent to the sewage treatment device for harmless treatment;

The food waste conveying device is used for conveying dehydrated solid food waste and solid food waste after liquid phase separation to the domestic waste and food waste mixing system.

Preferably, the kitchen waste pretreatment system further includes a heating system, and the oil-phase material after the oil extraction treatment is heated by the heating system and then transported to the waste pyrolysis system for pyrolysis.

Preferably, the food waste conveying device comprises a closed casing, a hot air inlet is opened at the feed end of the casing, and an air outlet and a material outlet are opened at the discharge end.

Preferably, the household waste and kitchen waste mixing system includes a garbage receiving tank, a feeding hopper is arranged on one side of the upper part of the garbage receiving tank, the feeding end of the feeding hopper is located in the garbage receiving tank, and the discharging end is located outside the garbage receiving tank for garbage. The pyrolysis system supplies materials; a domestic garbage discharge hall is set on the upper side of the garbage receiving tank for unloading domestic garbage to the garbage receiving tank; the kitchen garbage conveying device of the kitchen garbage pretreatment system transfers the pretreated solid The kitchen waste is sent to the garbage receiving tank to be mixed with the domestic garbage; a leachate collection device for collecting the leachate at the bottom of the garbage receiving tank is arranged on the outside of the bottom of the garbage receiving tank, and the leachate collection device is connected with the leachate concentration device, and the leachate concentration device will concentrate The resulting supernatant is sent to the sewage treatment plant for harmless treatment, and the concentrate is sent to the garbage pyrolysis system for pyrolysis.

Preferably, the garbage receiving tank is a negative pressure closed workshop, and a closed electric rolling shutter door is installed at the discharge hall of the domestic garbage; the air outlet and the material outlet of the discharge end of the kitchen garbage conveying device are located in the garbage receiving tank.

Preferably, the waste pyrolysis system includes a waste pyrolysis gasifier and a pyrolysis gas combustion and utilization device; the waste pyrolysis gasifier is used for pyrolysis and gasification of domestic waste, kitchen waste and treated waste from the waste receiving tank. Concentrate the leachate and oil phase materials; the pyrolysis gas combustion and utilization device burns and utilizes the gas generated in the pyrolysis gasifier, and the generated electrical energy or thermal energy is utilized as energy output.

Preferably, a leachate atomization spray device, a crude oil atomization spray device, a gas outlet and a burner are arranged on the top of the garbage pyrolysis gasifier; garbage is provided above the feed port of the garbage pyrolysis gasifier. The feeding hopper of the receiving tank; a gasification agent inlet is arranged on the lower side of the pyrolysis gasifier, and a slag collection and utilization system is arranged at the bottom of the pyrolysis gasifier; the concentrated leachate at the bottom of the garbage receiving tank is sent to the The leachate atomization spray device is sprayed into the furnace for pyrolysis, and the oil phase material extracted by the oil extraction device is heated and sent to the crude oil atomization spray device for pyrolysis in the furnace.

Preferably, the pyrolysis gas combustion and utilization device performs pretreatment such as heating, tar removal, dust removal, or reforming before the combustion of the gas.

Preferably, the waste heat utilization system divides the hot air after heat exchange into three feedback outputs, one is transported to the kitchen waste conveying device to heat the waste and then enters the waste receiving tank; the other is transported to the feeding hopper of the waste receiving tank for heating After the garbage, it enters the garbage receiving tank; all the way, it is transported as a gasification agent to the inlet of the gasification agent of the pyrolysis gasifier.

The invention also provides a method for synergistic pyrolysis treatment of kitchen waste and domestic waste, comprising the steps of:

Step 1. Pretreatment of kitchen waste

The kitchen waste is crushed and solid-liquid separated by the kitchen waste pretreatment system to generate solid kitchen waste and liquid phase materials. The solid kitchen waste is transported to the mixing place of kitchen waste and domestic waste, and the liquid phase materials are processed by oil extraction. produce oil phase material and water phase material;

Step 2. Mix pretreated kitchen waste with household waste:

The solid kitchen waste and domestic waste are mixed and stacked, and the leachate at the bottom of the mixed waste is collected at the same time, and the leachate is concentrated to obtain a supernatant and a concentrate;

Step 3. Pyrolysis and gasification of mixed domestic waste and kitchen waste

The mixed waste is sent to the pyrolysis gasifier for pyrolysis and gasification, while the oil phase material in step 1 is heated and then transported to the pyrolysis gasifier for pyrolysis and gasification, and the concentrate in step 2 is transported to the pyrolysis gas Pyrolysis and gasification in the furnace; the combustion and utilization of the gas generated by the pyrolysis and gasification, and the generated electric energy or thermal energy is used as the energy output;

Step 4. Waste heat utilization

The high-temperature flue gas generated by the combustion of gas is discharged after being purified and reached the standard after being utilized by the waste heat of heat exchange;

Step 5. Sewage treatment

The concentrated supernatant of the leachate in step 2 and the water-phase material after oil extraction in step 1 are respectively sent to a sewage treatment device for harmless treatment, and discharged after reaching the standard.

Preferably, in step 1, the solid-liquid separation includes two solid-liquid separations, the first solid-liquid separation dehydrates the crushed kitchen waste, and the second solid-liquid separation further solid-liquid separation of the slurry produced after dehydration.

Preferably, in step 1, the solid kitchen waste after the two solid-liquid separations has a solid content of 30-40%.

Preferably, in step 2, domestic waste and kitchen waste are mixed and stacked in a negative pressure airtight environment.

Preferably, in step 2, the concentrated solution after the diafiltrate is concentrated has a solid content of 10-20%.

Preferably, in step 3, the pyrolysis gasification reaction temperature in the pyrolysis gasifier is 550-900°C, the solid phase residence time is 8-25s, the gas phase residence time is 0.3-1.8s, and the excess air coefficient is 0.5-0.7 .

Preferably, in step 3, both the oil-phase material and the concentrated liquid enter the furnace for pyrolysis and gasification by spraying in the pyrolysis gasifier.

Preferably, in step 3, the heating temperature of the oil phase material is 60-80°C.

Preferably, in step 4, the hot air generated after the waste heat utilization is divided into three paths for recycling, wherein one path heats the solid kitchen waste after solid-liquid separation in step 2, and the heated air enters the domestic garbage and kitchen garbage Mixed stacking place, one of which heats the mixed waste at the feed hopper before entering the pyrolysis gasifier in step 3 and then enters the mixed stacking place of domestic waste and kitchen waste, and one of them is used as the gasification agent of the pyrolysis gasifier .

Preferably, in step 3, the burner of the pyrolysis gasifier is used as the start-up ignition device and the combustion-supporting device, and works when the start-up or processing system load is low or the calorific value of the incoming waste is low.

The advantages of the present invention are:

The food waste and domestic waste co-pyrolysis treatment system can realize the synergistic energy treatment of domestic waste and food waste, and solve the problem of single raw materials in traditional waste treatment technology;

The pyrolysis treatment system is aimed at the treatment of kitchen waste. Through pretreatment, the moisture content of the kitchen waste is reduced. The crude oil extracted by the oil extraction device is directly sent to the waste pyrolysis gasifier through the heating system, which avoids the need for a larger project scale. The hourly cost of crude oil storage, processing and transportation can also be used as a combustion aid for the waste pyrolysis gasification system to improve the operation stability of the waste pyrolysis system;

After the pyrolysis treatment system concentrates the landfill leachate, the concentrated solution is sprayed back into the landfill pyrolysis gasifier for gasification, which reduces the amount of leachate discharged and greatly reduces ammonia nitrogen, COD, organic matter, heavy metals and other pollutants in the leachate. emissions;

The system is environmentally friendly and has good environmental performance. The waste receiving tank adopts the form of closed negative pressure, which greatly reduces the diffusion of odor; the concentrated leachate is rich in a large amount of pollutants, which is treated by the pyrolysis gasification system to reduce pollutant discharge; Discharge after reaching the standard treatment; the slag produced by pyrolysis is used for resource utilization, and the flue gas after combustion and utilization of pyrolysis gas is purified and discharged up to the standard; the induced draft fan introduces odorous wind from the garbage receiving tank, and part of it returns to the garbage after heat exchange The receiving pool avoids direct wind from the atmosphere;

The pyrolysis system is stable and adaptable to raw materials. The system can process kitchen waste, domestic waste, leachate concentrate, and kitchen waste crude oil at the same time. The waste pyrolysis gasifier is equipped with a burner and a crude oil spray device. As a combustion-supporting system, it can adapt to the operating conditions of low system load and low calorific value of raw materials;

Cascade utilization of energy, high energy efficiency, after the pyrolysis gas is used by the combustion utilization device, the waste heat is fully utilized, and the air heated by the waste heat can be used as a gasification agent (avoiding room temperature air as a gasification agent), heating the waste into the furnace (Increase the temperature of the garbage entering the furnace and reduce the water content, thereby increasing the calorific value of the garbage entering the gasifier), heating and dehydrating the kitchen (reducing the kitchen, sludge (from the leachate collection tank), solid slag entering the garbage receiving tank) and other moisture content), realizing the cascade utilization of energy and high energy utilization efficiency.

Description of drawings

FIG. 1 is a schematic structural diagram of the synergistic pyrolysis treatment system for kitchen waste and domestic waste according to the present invention.

FIG. 2 is a schematic structural diagram of a receiving device.

Figure 3 is a schematic view of the structure of the crushing device.

FIG. 4 is a schematic structural diagram of the first solid-liquid separation device of the present invention.

FIG. 5 is a schematic structural diagram of the second solid-liquid separation device of the present invention.

FIG. 6 is a schematic structural diagram of the dehydration kitchen waste conveying device of the present invention.

Figure 7 is a schematic structural diagram of the waste pyrolysis gasifier.

1-Receiver, 101-Hopper, 102-Screw feeder, 103-Discharge port

2- crushing device, 201- crusher material inlet, 202- crusher material outlet

3-The first solid-liquid separation device, 301-material inlet, 302-slurry outlet, 303-solid kitchen waste outlet

4-Second solid-liquid separation device, 401-material inlet, 402-liquid phase material outlet, 403-solid kitchen waste outlet

5- Oil lift device

6- Heating system

7- Sewage treatment plant

8- Leachate concentration device

9- Leachate collection device

10-Dehydration kitchen conveying device, 1001-belt conveyor, 1002-shell, 1003-hot air inlet, 1004-air outlet, 1005-material outlet

11- Garbage receiving tank, 1101- Electric rolling shutter door, 1102- Garbage unloading hall, 1103- Grab truck, 1104- Feed hopper

12- Garbage pyrolysis gasifier, 1201- Garbage feed inlet, 1202- Concentrated leachate atomization spray device, 1203- Crude oil atomization spray device, 1204- Gasifier body, 1205- Combustible gas outlet, 1206-burner, 1207-gasification agent inlet, 1208- slag collection and utilization system

13-Pyrolysis gas combustion utilization device

14- Waste Heat Utilization System, 1401- Induced Fan, 1402- Blower

15- Flue gas purification system

Detailed ways

According to the above technical solution, a preferred embodiment is given and described in detail with reference to the drawings, with specific reference to FIG. 1 to FIG. 7 .

The food waste and domestic waste collaborative pyrolysis treatment system of the present invention includes a food waste pretreatment system, a domestic waste and a food waste mixing system, a sewage treatment device, a waste pyrolysis system, a waste heat utilization system, and a flue gas purification system;

The kitchen waste pretreatment system crushes and separates the kitchen waste from solid and liquid, and sends the solid kitchen waste materials to the domestic waste and the kitchen waste mixing system to mix with the domestic waste, and the liquid phase materials are subjected to oil extraction treatment to obtain the oil phase materials. and water phase materials;

The domestic waste and kitchen waste mixing system mixes the domestic waste and the pretreated kitchen waste;

The waste pyrolysis system pyrolyzes and gasifies the mixed domestic waste and kitchen waste, the oil-phase material treated by oil extraction, and the concentrate of the leachate in the mixed system of domestic waste and kitchen waste, and burns the generated gas. The generated electrical or thermal energy is utilized as an energy output;

The waste heat utilization system exchanges heat between the high-temperature flue gas after gas combustion and the normal temperature air from the household waste and kitchen waste mixing system, and the heated hot air is fed back to the solid-phase kitchen waste material for heating and pyrolysis of waste before gasification. Heating and as a gasifier for pyrolysis gasifiers;

The sewage treatment device conducts harmless treatment of the concentrated supernatant of the leachate of the domestic waste and kitchen waste mixing system and the water-phase material after the oil extraction of the kitchen waste;

Flue gas purification system purification The flue gas generated by the waste pyrolysis system is purified to meet the standards such as dust removal, dechlorination, desulfurization, destocking, and dioxin removal.

In the following, the pyrolysis treatment system will be described in detail, and the treatment devices involved are all commercially available.

The kitchen waste pretreatment system includes a receiving device 1 , a crushing device 2 , a first solid-liquid separation device 3 , a second solid-liquid separation device 4 , an oil extraction device 5 , a heating system 6 , and a dewatered food waste conveying device 10 .

The receiving device 1 includes a hopper, a screw discharger 102 is provided at the bottom of the hopper 101, and a discharge port 103 is provided at the discharge end of the screw discharge port. The kitchen waste is sent to the hopper 101 by the garbage conveying vehicle, and then the food waste is sent through the discharge port 103 by the screw feeder, and then sent to the crushing device 2 for crushing by the screw feeder.

The crushing device 2 includes a box body, and a crusher is arranged in the box body, a material inlet 201 of the crusher and an outlet 202 of the material of the crusher. The crusher can be one or a combination of hammer crusher, impact crusher, shear crusher or roller crusher. After the kitchen waste is received by the receiving device, it enters the crusher through the material inlet 201 of the crusher to be crushed, and the crushed material is sent to the first solid-liquid separation device 3 through the material outlet 202 of the crusher for dehydration.

The first solid-liquid separation device 3 includes a dehydrator, a material inlet 301, a slurry outlet 302 and a solid kitchen waste outlet 303. The dehydrator is one or a combination of a screw extrusion dehydrator, a centrifugal dehydrator or a belt filter press. After the kitchen waste is crushed by the crushing device, it is sent to the dehydrator through the material outlet 202 of the crusher and the material inlet 301 of the first solid-liquid separation device for dehydration. The solid content of the dehydrated solid kitchen waste is 30-40%. The dehydrated solid food waste is sent to the dehydrated food waste conveying device 10 through the solid food waste outlet 303, and is sent to the food waste and domestic waste mixing system through the dehydrated food waste conveying device 10 to be mixed with the domestic waste. The slurry generated after the dehydration of the kitchen waste is sent to the second solid-liquid separation device 4 through the slurry outlet 302 for further solid-liquid separation.

The second solid-liquid separation device 4 is provided with a material inlet 401 , a liquid-phase material outlet 402 and a solid kitchen waste outlet 403 . The second solid-liquid separation device can also use one or a combination of a screw extrusion dehydrator, a centrifugal dehydrator or a belt filter press; compared with the first solid-liquid separation device 3, due to the small solid particles in the slurry, Therefore, the mesh number of the screen of the second solid-liquid separation device is larger. The dehydrated slurry enters the second solid-liquid separation device 4 through the material inlet 401 for further solid-liquid separation, and then the solid food waste is sent to the dehydrated food waste conveying device 10 through the solid food waste outlet 403, and passes through the dehydrated food waste. The garbage conveying device 10 is sent to the kitchen garbage and domestic garbage mixing system to be mixed with the domestic garbage. The liquid phase material is sent to the oil extraction device 5 through the liquid phase material outlet 402 for oil-water separation.

The oil-lifting device 5 performs oil-lifting treatment on the liquid-phase material after solid-liquid separation by the second solid-liquid separation device 4 to separate oil and water. After the oil-water separation, the oil-phase material in the upper layer, that is, the crude oil, is transported to the heating system 6 for heating and then sent to the waste pyrolysis system for pyrolysis. The water phase of the lower layer is sent to the sewage treatment device 7 for harmless treatment, and discharged after reaching the standard. The heating system 6 adopts electric heating or gas heating. The heating system 6 controls the temperature of the delivered crude oil to be 60-80°C by heating. The heating system 6 heats the upper crude oil of the oil lifting device 5, which can ensure that the crude oil transportation pipeline and pump will not solidify and the pipeline and pump will not be blocked when the ambient temperature is low throughout the year.

The food waste conveying device 10 includes a belt conveyor 1001 and a conveying device casing 1002 arranged outside the belt conveyor; the solid food waste inlet of the first solid-liquid separation device and the second solid food waste are arranged on the casing of the conveying device. The solid food waste inlet of the liquid separation device 4 sends the solid food waste after solid-liquid separation to the belt conveyor. A hot air inlet 1003, an air outlet 1004, and a material outlet 1005 are also arranged on the casing of the conveying device; the air outlet 1004 and the material outlet 1005 are both located at the output end of the belt conveyor 1001, and the material outlet 1005 is located under the casing of the conveying device, which is convenient for Discharge.

In the kitchen waste pretreatment system, in order to reduce the occupied area of the space plane, the devices are arranged in layers as reasonably as possible to fully improve the utilization rate of space volume; at the same time, the effect of gravity is used to accelerate the conveying speed.

The household waste and kitchen waste mixing system includes a garbage receiving tank 11, and a garbage discharge hall 1102 is arranged on the upper side of the garbage receiving tank 11, and the garbage discharge hall is communicated with the garbage receiving tank. The garbage discharge hall is provided with an electric rolling shutter door 1101 , and the domestic garbage transport vehicle enters the garbage discharge hall 1102 through the electric rolling shutter door 1101 , and dumps the domestic garbage into the garbage receiving tank 11 . A grab truck 1103 is provided on the top of the garbage receiving tank 11, and a feeding hopper 1104 is provided on the other side of the garbage receiving tank. Above the waste pyrolysis gasifier 12 , the grabbing trolley 1103 grabs the mixture of domestic waste and kitchen waste, and sends it to the waste pyrolysis gasifier 12 through the feed hopper 1104 for pyrolysis and gasification. The bottom and side walls of the feeding hopper 1104 are equipped with heating tuyere, and the heating tuyere for hot air enters the feeding hopper 1104 to heat the garbage in the feeding hopper; meanwhile, the air after heating the garbage enters the garbage receiving tank 11 .

The garbage receiving tank 11 is a negative pressure closed workshop. The electric rolling shutter door 1101 is only opened when the domestic garbage transporter is unloading, and is closed at the rest of the time to prevent the leakage of foul air and pollute the environment.

The discharge end of the kitchen waste conveying device 10 extends into the garbage receiving tank 11 from one side, and the air outlet 1004 and the material outlet 1005 are respectively located in the garbage receiving tank 11 . The dewatered and solid-liquid separated solid kitchen waste is sent to the garbage receiving tank 11 through the material outlet 1005 by the kitchen garbage conveying device 10 and mixed with the domestic garbage at the bottom of the garbage receiving tank. The air outlet 1004 can output the air in the food waste conveying device 10 to the waste receiving tank 11 to avoid environmental pollution, and meanwhile the residual heat of the air can be returned to the garbage tank to increase or maintain the temperature in the garbage tank. The garbage is stacked in the garbage receiving tank for 5-7 days and then sent to the pyrolysis gasifier for pyrolysis and gasification.

The discharge end of the food waste conveying device 10 and the waste discharge hall need to keep a sufficient distance from the bottom of the waste receiving tank 11, and the kitchen waste and domestic waste fall into the garbage receiving tank by gravity, making full use of the space volume, and no other External force to carry out operations such as roll stacking.

A leachate collecting device 9 is arranged on the outside of the bottom of the garbage receiving tank 11 near the kitchen waste pretreatment system. The leachate collecting device 9 is a storage tank structure and communicates with the bottom of the garbage receiving tank 11 through a filter screen for collecting garbage. Leachate in receiving tank 11.

The leachate concentration device 8 is communicated with the leachate collecting device 9, and the leachate collected by the leachate collecting device 9 is concentrated to obtain a supernatant and a concentrated solution, and the solid content of the concentrated solution is 10-20%. The concentrated solution is sent to the waste pyrolysis gasifier 12 for spray pyrolysis. The sludge at the bottom of the leachate collection device 9 is conveyed to the kitchen waste conveying device 10, and then conveyed to the waste receiving tank, and then sent to the waste pyrolysis gasifier for processing.

The sewage treatment device 7 sends the concentrated supernatant to the sewage treatment device 7 for treatment, and the water-phase material after oil extraction by the oil extraction device is sent to the sewage treatment device 7 for treatment. The sewage treatment device 7 treats the water-phase material after oil extraction and the supernatant liquid from the leachate concentration device 8 and discharges them up to the standard.

The waste pyrolysis system includes a waste pyrolysis gasifier 12 and a pyrolysis gas combustion and utilization device 13 .

The waste pyrolysis gasifier 12 is an upward suction type fixed bed gasifier. It includes a garbage feeding port 1201, a concentrated leachate atomization spray device 1202, a crude oil atomization spray device 1203, a gasifier body 1204, a combustible gas outlet 1205, a burner 1206, a gasification agent inlet 1207, and slag collection. Utilize system 1208.

The garbage feeding port 1201 is located above the gasifier body 1204, and a feeding hopper 1104 is provided above the garbage feeding port 1201; In the hopper 1104, the garbage is fed into the garbage pyrolysis gasifier through the feeding hopper 1104 and the garbage feeding port 1201.

A concentrated leachate atomizing and spraying device 1202 and a crude oil atomizing and spraying device 1203 are arranged at the top of the gasifier body on the side of the garbage feeding port 1201 . The combustible gas outlet 1205 and the burner 1206 are respectively located in the upper part of the gasifier. The gasification agent inlet 1207 is located on the lower side of the gasifier, and the slag collection and utilization system 1208 is located at the bottom of the gasifier. The burner 1206 is a diesel burner or a biogas burner or a natural gas burner or an oil-gas mixed burner.

The gasification agent is fed into the waste pyrolysis gasification furnace 12 through the gasification agent inlet 1207 at the lower part of the gasification furnace. The pyrolysis gasification reaction temperature in the waste pyrolysis gasification furnace 12 is 550-900°C, and the solid phase residence time is 550-900°C. It is 8-25s, the gas phase residence time is 0.3-1.8s, and the excess air coefficient is 0.5-0.7. The concentrated solution concentrated by the leachate concentration device 8 is transported to the pyrolysis gasification furnace, and the concentrated leachate atomization spray device 1202 is sprayed into the furnace body from the upper part of the furnace body for pyrolysis and gasification. The crude oil heated by the heating system 6 is transported to the pyrolysis gasifier, and is sprayed into the waste pyrolysis gasifier 12 as fuel through the crude oil atomization spray device 1203 for combustion; the burner 1206 is used as a furnace starter ignition device and Combustion-supporting device works when the furnace is started or when the load of the processing system is low or the calorific value of the incoming waste is low. It is used to compensate the thermal imbalance of the system when the calorific value of the incoming waste is low or the load of the processing system is low, and maintain the normal operation of the pyrolysis gasifier. It can be reused. The slag collection and utilization system 1208 adopts wet slag discharge. The slag is discharged by a wet slag extractor. The discharged slag can be used as a low-grade road subgrade material for resource utilization. The combustible gas outlet 1205 transports the gas generated in the pyrolysis gasifier to the pyrolysis gas combustion and utilization device 13 .

The pyrolysis gas combustion and utilization device 13 is a gas turbine generator set or an internal combustion engine generator set or a gas heating boiler. Before combustion and utilization of the gas generated by the pyrolysis gasifier, different types of pyrolysis gas combustion and utilization device 13 are selected. Gas pretreatment, gas pretreatment includes heating, tar removal, dust removal, reforming, etc. The pyrolysis gas combustion and utilization device 13 outputs and utilizes energy such as electric energy and thermal energy generated by burning gas, and the generated low-grade thermal energy, that is, high-temperature flue gas, enters the waste heat utilization system 14 .

The waste heat utilization system 14 adopts a heat exchanger to recover the low-grade heat energy generated by the pyrolysis gas combustion and utilization device 13, that is, the high-temperature flue gas. The room temperature air drawn from the waste receiving tank 11 by the induced draft fan 1401 enters the waste heat utilization system 14, and exchanges heat with the high temperature flue gas in the waste heat utilization system 14, further improving the energy utilization efficiency and realizing the cascade utilization of energy. The heated hot air is divided into three outputs, and one hot air enters the feeding hopper 1104 through the heating tuyere on the feeding hopper 1104 through the blower 1402 for heating the garbage, and at the same time enters the garbage receiving tank 11 through the feeding hopper 1104 In order to maintain a slight negative pressure in the garbage receiving tank 11, the diffusion of odor in the garbage receiving tank 11 can be avoided; one way enters the garbage pyrolysis gasifier 12 through the gasification agent inlet 1207 as a gasification agent; the other way passes through the dehydration The hot air inlet 1003 on the kitchen conveying device 10 enters the housing of the conveying device to heat the garbage on the conveyor belt, and the air whose temperature is reduced after heating enters the garbage receiving tank 11 through the air outlet 1004, so as to keep the inside of the garbage receiving tank 11 at a low temperature. Negative pressure, the air in the garbage receiving tank 11 enters the waste heat utilization system 14 through the induced draft fan 1401 for recycling and reuse.

After heat exchange in the waste heat utilization system 14, the flue gas with reduced temperature enters the flue gas purification system 15, and the flue gas is de-stocked, desulfurized, dedusted, dechlorinated, treated with dioxins, treated with fly ash stabilization, etc.; the purified flue gas meets the standard rear discharge.

The co-pyrolysis treatment method for kitchen waste and domestic waste using the above pyrolysis system includes the following steps:

Step 1. Pretreatment of kitchen waste

The kitchen waste is crushed and dehydrated to obtain solid kitchen waste and slurry; the slurry is subjected to solid-liquid separation to obtain solid kitchen waste and liquid-phase materials; the liquid-phase materials are subjected to oil extraction treatment to obtain oil-phase materials and water-phase materials, Heating the oil phase material;

Step 2. Mix pretreated kitchen waste with household waste:

The fixed food waste obtained from dehydration and the solid food waste obtained from solid-liquid separation are sent to the garbage receiving tank to be mixed with domestic garbage, and the leachate at the bottom of the garbage receiving tank is collected at the same time, and the leachate is concentrated to obtain supernatant and concentrate. ;

Step 3. Pyrolysis and gasification of mixed domestic waste and kitchen waste

The mixed household waste and kitchen waste are sent to the pyrolysis gasifier for pyrolysis and gasification, while the heated oil phase material in step 1 is transported to the pyrolysis gasifier for pyrolysis and gasification, and the step 2 The concentrated liquid is transported to the pyrolysis gasification furnace for pyrolysis gasification; the gas generated by the pyrolysis gasification is burned and utilized, and the generated electric energy or heat energy is used as energy output;

Step 4. Waste heat utilization

The high-temperature flue gas generated by the combustion of gas is discharged after being purified and reached the standard after being utilized by the waste heat of heat exchange;

Step 5. Sewage treatment

In step 2, the collected leachate is concentrated and the supernatant and the water-phase material after oil extraction in step 1 are respectively sent to the sewage treatment device for harmless treatment, and discharged after reaching the standard.

Specific examples are given below for description.

Example 1

In this embodiment, the synergistic pyrolysis treatment system of kitchen waste and domestic waste is used to implement the coordinated harmless treatment and energy utilization of kitchen waste and domestic waste.

The daily feeding amount of domestic waste is 60t, the moisture content is 45%, and the low calorific value is 5500kJ/kg. The daily feeding amount of kitchen waste is 10t/d, the moisture content is 80%, and the oil content is 5%.

The kitchen waste is sent to the receiving device 1 by the garbage truck for storage, and then sent to the crushing device 2 through the screw feeder for crushing. The crushed kitchen waste is transported to the Dehydration is performed in the first solid-liquid separation device 3 to obtain solid kitchen waste and slurry, the solid content of the solid kitchen waste is 37%, and the solid kitchen waste is transported to the kitchen waste conveying device 10 . Since the dehydrated slurry also contains a certain amount of solid waste, the dehydrated slurry is sent to the second solid-liquid separation device 4 for further solid-liquid separation, and the separated solid food waste is sent to the food waste conveying device through the conveying device In 10, the moisture content of the dehydrated solid food waste and the solid food waste after solid-liquid separation will be about 62%; on the food waste conveying device 10, the food waste is continuously heated by hot air during the conveying process, The moisture content upon entering the refuse receiving tank 11 dropped to 53%.

The liquid-phase material produced after separation is sent to the oil-lifting device 5 for oil-lifting treatment, and the crude oil of the upper layer is collected and transported to the heating system 6 and heated to 75 ° C, and then transported to the pyrolysis gasifier through pipelines. The crude oil atomization spray device is sprayed into the furnace of the pyrolysis gasifier for pyrolysis and gasification.

The water-phase material after the oil-lifting treatment by the oil-lifting device is sent to the sewage treatment device 7 for innocuous treatment after reaching the standard and then discharged.

Open the electric rolling shutter door, the garbage truck loaded with household garbage passes through the electric rolling shutter door and unloads in the garbage unloading hall. The domestic garbage from the unloading hall falls into the garbage receiving tank 11 under the action of gravity and is mixed with the pretreated kitchen waste. After 7 days of stacking of the domestic waste and kitchen waste entering the garbage receiving tank, the overall moisture content of the mixed garbage is further reduced to 38%, and is sent to the feed hopper by grabbing trucks. After the overall moisture content of the mixed waste is reduced to 32%, it enters the furnace of the pyrolysis gasifier for pyrolysis and gasification. The heated air enters through the gasification agent inlet at the bottom of the gasifier, the heating air temperature is 95°C, and the excess air coefficient in the gasifier is 0.6. The gasification temperature in the gasifier is 810°C, the solid phase residence time is 15s, and the gas phase residence time is 1.2s.

The leachate at the bottom of the garbage receiving tank 11 is collected by the leachate collection device 9, and then sent to the leachate concentration device 8 for concentration. The concentrated liquid is sent to the leachate atomization spray device installed in the pyrolysis gasifier and sprayed into the furnace for pyrolysis and gasification, and the supernatant liquid is sent to the sewage treatment device 7 for harmless treatment and discharge after reaching the standard.

The gas generated by pyrolysis and gasification enters the gas heating boiler 13 for combustion, and the gas heating boiler supplies heat for external heat users. The high-temperature flue gas generated by the gas boiler enters the waste heat utilization system 14, and the heat exchange is carried out through the waste heat utilization system. After heating the air from the garbage receiving tank to 95°C, the heated air is divided into three paths and enters the pyrolysis gasifier respectively. It is heated at the feeding hopper, the inlet of the gasification agent, and the food waste conveying device. The flue gas after heat exchange by the waste heat utilization system is discharged after reaching the standard after purification treatment such as dust removal, dechlorination, destocking, desulfurization, and dioxin treatment in the flue gas purification system. Make use of resources.

Example 2

In this embodiment, the synergistic pyrolysis treatment system of kitchen waste and domestic waste is used to implement the coordinated harmless treatment and energy utilization of kitchen waste and domestic waste. In this example, the daily feeding amount of domestic waste is 220t, the water content is 51%, the low calorific value is 5100kJ/kg, the daily feeding amount of kitchen waste is 20t/d, the water content is 85%, and the oil content is 4 %.

The kitchen waste is sent to the receiving device 1 by the garbage truck for storage, and then sent to the crushing device 2 through the screw feeder for crushing. The crushed kitchen waste is transported to the Dehydration is performed in the first solid-liquid separation device 3 to obtain solid kitchen waste and slurry, the solid content of the solid kitchen waste is 36%, and the solid kitchen waste is transported to the kitchen waste conveying device 10 . Since the dehydrated slurry also contains a certain amount of solid waste, the dehydrated slurry is sent to the second solid-liquid separation device 4 for further solid-liquid separation, and the separated solid food waste is sent to the food waste conveying device through the conveying device In 10, the moisture content of the dehydrated solid food waste and the solid food waste after solid-liquid separation will be about 65%; on the food waste conveying device 10, the food waste is continuously heated by hot air during the conveying process, The moisture content at the time of entering the refuse receiving tank 11 dropped to 57%.

The liquid-phase material produced after separation is sent to the oil-lifting device 5 for oil-lifting treatment, and the crude oil of the upper layer is collected and transported to the heating system 6 and heated to 72 ° C, then transported to the pyrolysis gasifier through the pipeline, and passed The crude oil atomization spray device is sprayed into the furnace of the pyrolysis gasifier for pyrolysis and gasification.

The water-phase material after the oil-lifting treatment by the oil-lifting device is sent to the sewage treatment device 7 for innocuous treatment after reaching the standard and then discharged.

Open the electric rolling shutter door, the garbage truck loaded with household garbage passes through the electric rolling shutter door and unloads in the garbage unloading hall. The domestic garbage from the unloading hall falls into the garbage receiving tank 11 under the action of gravity and is mixed with the pretreated kitchen waste. After 5 days of stacking of domestic waste and kitchen waste entering the waste receiving tank, the overall moisture content of the mixed waste is further reduced to 43%, and is sent to the feed hopper by grabbing trucks. After the overall moisture content of the mixed waste is reduced to 37%, it enters the furnace of the pyrolysis gasifier for pyrolysis and gasification. The heated air enters through the gasification agent inlet at the bottom of the gasifier, the heating air temperature is 100°C, and the excess air coefficient in the gasifier is 0.65. The gasification temperature in the gasifier is 890°C, the solid phase residence time is 20s, and the gas phase residence time is 1.6s. In order to ensure a good reaction condition in the pyrolysis gasifier, a diesel burner is used for combustion support.

The leachate at the bottom of the garbage receiving tank 11 is collected by the leachate collection device 9, and then sent to the leachate concentration device 8 for concentration. The concentrated liquid is sent to the leachate atomization spray device installed in the pyrolysis gasifier and sprayed into the furnace for pyrolysis and gasification, and the supernatant liquid is sent to the sewage treatment device 7 for harmless treatment and discharge after reaching the standard.

The gas generated by pyrolysis and gasification enters the gas turbine generator set 13 for combustion. The pyrolysis gasification gas undergoes tar removal and dust removal pretreatment before entering the gas turbine, and then enters the gas turbine generator set. The power generation part of the gas turbine generator set is used for system power consumption, and the rest Part of it enters the grid for consumption. The high-temperature flue gas used by the gas turbine generator set enters the waste heat utilization system 14, and the heat exchange is carried out through the waste heat utilization system. After heating the air from the garbage receiving pool to 100 °C, the heated air is divided into three paths and enters the pyrolysis gasification. Heating is carried out at the feeding hopper of the furnace, the inlet of the gasification agent, and the food waste conveying device. The flue gas after heat exchange by the waste heat utilization system is discharged after reaching the standard after purification treatment such as dust removal, dechlorination, destocking, desulfurization, and dioxin treatment in the flue gas purification system. Make use of resources.

Claims (20)

1. A food waste and domestic waste collaborative pyrolysis treatment system is characterized in that, comprising a food waste pretreatment system, a domestic waste and a food waste mixing system, a sewage treatment device, a waste pyrolysis system, a waste heat utilization system, flue gas purification system; The kitchen waste pretreatment system separates the kitchen waste from solid and liquid, transports the solid kitchen waste to the domestic waste and the kitchen waste mixing system and mixes it with the domestic waste, and carries out the oil extraction treatment of the liquid material; The domestic waste and kitchen waste mixing system mixes the domestic waste and the pretreated kitchen waste; The waste pyrolysis system pyrolyzes and gasifies the mixed domestic waste and kitchen waste, the oil-phase material treated by oil extraction, and the concentrate of the leachate in the mixed system of domestic waste and kitchen waste, and burns the generated gas. The generated electrical or thermal energy is utilized as an energy output; The waste heat utilization system exchanges the heat of the high temperature flue gas after gas combustion with the normal temperature air at the mixing system of domestic waste and kitchen waste and feeds it back to the pyrolysis treatment system; The sewage treatment device conducts harmless treatment of the concentrated supernatant of the leachate of the domestic waste and kitchen waste mixing system and the water-phase material after the oil extraction of the kitchen waste; Flue gas purification system purification The flue gas generated by the waste pyrolysis system is subjected to dust removal, dechlorination, desulfurization, destocking, and dioxin removal and purification to meet the standards. 2. The food waste and domestic waste co-pyrolysis treatment system according to claim 1, wherein the food waste pretreatment system comprises a receiving device, a crushing device, a first solid-liquid separation device, and a second solid-liquid separation device. Separation device, oil extraction device, kitchen waste conveying device; The receiving device sends the received kitchen waste to the crushing device for crushing; The first solid-liquid separation device dehydrates the crushed kitchen waste to obtain slurry and solid kitchen waste; The second solid-liquid separation device further separates the dehydrated slurry from solid-liquid to obtain solid kitchen waste and liquid-phase materials; The oil-lifting device performs oil-lifting treatment on the liquid-phase material after solid-liquid separation, so as to separate the oil and water to obtain the oil-phase material and the water-phase material, and the water-phase material is sent to the sewage treatment device for harmless treatment; The food waste conveying device is used to transport the solid food waste after solid-liquid separation to the domestic waste and food waste mixing system. 3. The food waste and domestic waste synergistic pyrolysis treatment system according to claim 2, wherein the food waste pretreatment system further comprises a heating system, and the oil-phase material after the oil extraction treatment is heated by the heating system and then transported to the waste pyrolysis system for pyrolysis. 4. The food waste and domestic waste co-pyrolysis treatment system according to claim 2, wherein the food waste conveying device comprises a closed shell, and a hot air inlet is opened at the feeding end of the shell, and a hot air inlet is provided at the outlet. The material end is provided with an air outlet and a material outlet. 5. The food waste and household waste co-pyrolysis treatment system according to claim 1, wherein the household waste and food waste mixing system comprises a garbage receiving tank, and a feeding hopper is provided on one side of the upper part of the garbage receiving tank , the feeding end of the feeding hopper is located in the garbage receiving tank, and the discharging end is located outside the garbage receiving tank to feed the garbage pyrolysis system; there is a domestic garbage discharge hall on the upper side of the garbage receiving tank; the kitchen waste pretreatment system The kitchen waste conveying device sends the pretreated solid kitchen waste to the garbage receiving tank to be mixed with domestic garbage; a leachate collection device for collecting the leachate at the bottom of the garbage receiving tank is arranged on the outside of the bottom of the garbage receiving tank. The leachate concentration device is connected, and the leachate concentration device sends the concentrated supernatant to the sewage treatment device for harmless treatment, and sends the concentrated solution to the garbage pyrolysis system for pyrolysis. 6. The food waste and domestic waste co-pyrolysis treatment system according to claim 5, wherein the waste receiving tank is a negative pressure closed workshop, and the air outlet and the material outlet of the discharge end of the food waste conveying device are located at In the garbage receiving pond. 7. The collaborative pyrolysis treatment system for kitchen waste and domestic waste according to claim 1, wherein the waste pyrolysis system comprises a waste pyrolysis gasifier and a pyrolysis gas combustion and utilization device; the waste pyrolysis gasifier It is used for pyrolysis and gasification of domestic waste, kitchen waste and processed concentrated leachate and oil-phase materials from the waste receiving tank; The electrical or thermal energy is utilized as energy output. 8. The collaborative pyrolysis treatment system for kitchen waste and domestic waste according to claim 7, wherein the top of the waste pyrolysis gasifier is provided with a leachate atomization spray device, a crude oil atomization spray device, gas outlet and burner; the feed hopper of the waste receiving pool is set above the feed port of the waste pyrolysis gasifier; the gasification agent inlet is set on the lower side of the pyrolysis gasifier, and the bottom of the pyrolysis gasifier is set There is a slag collection and utilization system; the concentrated leachate at the bottom of the garbage receiving tank is sent to the leachate atomization and spraying device to be sprayed into the furnace for pyrolysis, and the kitchen waste is heated by the oil phase material extracted by the oil extraction device. It is sent to the spray furnace of the crude oil atomization spray device for pyrolysis. 9 . The co-pyrolysis treatment system for kitchen waste and domestic waste according to claim 7 , wherein the pyrolysis gas combustion and utilization device performs pretreatment before gas combustion. 10 . 10. The system for co-pyrolysis treatment of kitchen waste and domestic waste according to claim 1, wherein the waste heat utilization system divides the hot air after heat exchange into three paths of feedback output, and one path is transported to the kitchen garbage conveyor After the device heats the garbage, it enters the garbage receiving tank; all the way to the feeding hopper of the garbage receiving tank to heat the garbage and then enters the garbage receiving tank; all the way to the entrance of the gasification agent of the pyrolysis gasifier as a gasification agent. 11. A method for co-pyrolysis treatment of kitchen waste and domestic waste, the steps comprising: Step 1. Pretreatment of kitchen waste The kitchen waste is crushed and solid-liquid separated by the kitchen waste pretreatment system to generate solid kitchen waste and liquid phase materials. The solid kitchen waste is transported to the mixing place of kitchen waste and domestic waste, and the liquid phase materials are processed by oil extraction. produce oil phase material and water phase material; Step 2. Mix pretreated kitchen waste with household waste: The solid kitchen waste and domestic waste are mixed and stacked, and the leachate at the bottom of the mixed waste is collected at the same time, and the leachate is concentrated to obtain a supernatant and a concentrate; Step 3. Pyrolysis and gasification of mixed domestic waste and kitchen waste The mixed waste is sent to the pyrolysis gasifier for pyrolysis and gasification, while the oil phase material in step 1 is heated and then transported to the pyrolysis gasifier for pyrolysis and gasification, and the concentrate in step 2 is transported to the pyrolysis gas Pyrolysis and gasification in the furnace; the combustion and utilization of the gas generated by the pyrolysis and gasification, and the generated electric energy or thermal energy is used as the energy output; Step 4. Waste heat utilization The high-temperature flue gas generated by the combustion of gas is discharged after being purified and reached the standard after being utilized by the waste heat of heat exchange; Step 5. Sewage treatment The concentrated supernatant of the leachate in step 2 and the water-phase material after oil extraction in step 1 are respectively sent to a sewage treatment device for harmless treatment, and discharged after reaching the standard. The processing method according to claim 11, wherein in step 1, the solid-liquid separation comprises two solid-liquid separations, the first solid-liquid separation dehydrates the crushed kitchen waste, and the second solid-liquid separation The slurry produced after dehydration is subjected to further solid-liquid separation. 13 . The processing method according to claim 12 , wherein in step 1, the solid kitchen waste after two solid-liquid separations has a solid content of 30-40%. 14 . 14. The processing method according to claim 11, wherein in step 2, domestic waste and kitchen waste are mixed and stacked in a negative pressure airtight environment. 15 . The processing method according to claim 11 , wherein, in step 2, the concentration of the concentrated liquid after the diafiltrate is concentrated has a solid content of 10-20%. 16 . 16 . The processing method according to claim 11 , wherein in step 3, the pyrolysis gasification reaction temperature in the pyrolysis gasifier is 550-900° C., the solid-phase residence time is 8-25s, and the gas-phase residence time is 8-25 s. 17 . It is 0.3~1.8s, and the excess air coefficient is 0.5~0.7. 17. The processing method according to claim 11, characterized in that, in step 3, both the oil phase material and the concentrated liquid are sprayed into the furnace for pyrolysis and gasification in the pyrolysis gasifier. 18 . The processing method according to claim 11 , wherein, in step 3, the heating temperature of the oil phase material is 60-80° C. 19 . 19. The processing method according to claim 11, wherein in step 4, the hot air generated after the waste heat utilization is divided into three paths for recycling, wherein one path is for the solid kitchen waste after solid-liquid separation in step 2 After heating, the air enters the mixed storage place of domestic waste and kitchen waste, and the mixed waste at the feeding hopper before entering the pyrolysis gasifier in step 3 is heated and then enters the mixed storage place of domestic waste and kitchen waste. , one of which is used as the gasification agent of the pyrolysis gasifier. 20. The processing method according to claim 11, characterized in that, in step 3, the burner of the pyrolysis gasifier is used as the start-up ignition device and the combustion-supporting device, and the load of the start-up or treatment system is relatively low or the waste entering the furnace is Works when the calorific value is low.

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