Sludge-kitchen combined treatment multi-product collaborative recovery system and method

Abstract

The invention discloses a sludge-kitchen combined treatment multi-product collaborative recovery system and method, and belongs to the technical field of environmental protection and resource recovery. The system comprises a collection, transportation and classification unit, a grading pretreatment unit, a material distribution unit, an anaerobic digestion unit, a biogas treatment unit, a biogas slurry multi-product recovery unit, a biogas residue treatment unit and a kitchen residue recovery unit which are sequentially connected along a material flow direction. The method comprises the steps of receiving, transporting, classifying and grading pretreatment material distribution, anaerobic digestion biogas treatment, biogas slurry multi-product recovery biogas residue treatment and kitchen residue recovery. Impurities are removed in a targeted mode through grading pretreatment, cooperation is achieved through the material distribution unit, flexible adaptation of a diversion path is achieved, ammonia water and ammonium bicarbonate are produced as needed through the biogas slurry multi-product recycling unit, six products including crude oil, kitchen residue, biogas, carbon soil, ammonia water and ammonium bicarbonate are synchronously recycled, and full-chain resource utilization of waste is achieved; and the method has the advantages of flexible process, high economic benefit and remarkable environmental benefit.

Description

Technical Field

[0001] This invention relates to the field of environmental protection and resource recycling technology, and in particular to a synergistic recycling system and method for multiple products from combined treatment of sludge and kitchen waste. Background Technology

[0002] With the acceleration of urbanization, the production of municipal sludge and kitchen waste has surged. Both are characterized by high water content and high organic matter content, and improper disposal can easily lead to environmental pollution. Existing sludge and kitchen waste co-processing technologies suffer from problems such as single product and low resource utilization efficiency. Most processes focus only on a single product, such as biogas or carbonaceous soil, neglecting the extraction of valuable components such as crude oil, ammonia nitrogen, etc.; poor process synergy, with the pretreatment processes for kitchen waste and sludge being disconnected, and impurities interfering with the quality of downstream products; rigid ammonia nitrogen recovery pathways, unable to flexibly switch between ammonia water and ammonium bicarbonate according to market demand; unsystematic recovery of kitchen waste residue and crude oil, failing to fully explore resource value; and insufficient adaptability in synergy and diversion, making it difficult to cope with fluctuations in material composition. Therefore, developing a sludge and kitchen waste co-processing system that can achieve synergistic pretreatment, flexible product switching processes, and simultaneous recovery of ammonia water, ammonium bicarbonate, crude oil, kitchen waste residue, biogas, and carbonaceous soil has become the key to solving the above problems. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a sludge-kitchen waste co-processing multi-product synergistic recycling system and method, which achieves efficient synergistic treatment and multi-resource recycling of waste, and improves resource recovery rate and process economy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A sludge-food waste co-processing and multi-product co-recovery system is characterized by comprising, sequentially connected along the material flow direction, a collection and sorting unit, a graded pretreatment unit, a material distribution unit, an anaerobic digestion unit, a biogas treatment unit, a biogas slurry multi-product recovery unit, a biogas residue treatment unit, and a food waste recovery unit; the collection and sorting unit includes a food waste collection subunit, a food waste collection subunit, and a sludge collection subunit, each subunit being equipped with a negative pressure deodorization device; the graded pretreatment unit includes a food waste pretreatment subunit, a food waste pretreatment subunit, and a sludge pretreatment subunit; the material distribution unit includes a mixing tank, a sorting tank, and a distribution tank. The system includes flow valves and a temporary storage bin for kitchen waste; the anaerobic digestion unit is equipped with a centrifugal dehydrator and a biogas collection hood; the biogas treatment unit includes a desulfurization tower, a dehydrator, and a biogas storage tank; the biogas slurry multi-product recovery unit includes a purification module, a heat transfer module, a hardening removal tower, an ammonia recovery module, and a product switching module connected in sequence; the ammonia recovery module includes a stripping analysis tower, a stripping ammonia removal tower, a condenser, a gas-liquid separator, and an ammonia concentration tower connected in sequence; the product switching module includes a carbonization tower and an absorption tower arranged in parallel; the biogas residue treatment unit includes a low-temperature dryer, a screening machine, and a carbon soil conditioning tank; the kitchen waste recovery unit includes a dryer and a baler.

[0005] Furthermore, the kitchen waste pretreatment subunit is equipped with a draining device, a crushing and screening machine, a magnetic separator, an extrusion dewatering machine, and a sand and impurity removal machine in sequence along the material flow direction; the catering waste pretreatment subunit is equipped with a pulping machine, a sand remover, a hot water hydrolysis tank, a screw press oil extraction machine, and an impurity removal screen in sequence along the material flow direction; and the sludge pretreatment subunit is equipped with a sand removal tank, a pulping tank, and a stacked press dewatering machine in sequence along the material flow direction.

[0006] Furthermore, a compound scale inhibitor is added to the hardening tower at a dosage of 200 to 300 ppm to reduce the hardness of the biogas slurry to no more than 50 mg / L (calculated as CaCO3); the tube bundle of the hardening tower is made of inert material or has undergone surface treatment with inert material, and the inert material is one or more of stainless steel, titanium-titanium alloy, polytetrafluoroethylene, hexagonal boron nitride ceramic, glass lining, glass fiber reinforced plastic, or reinforced stainless steel.

[0007] Furthermore, the operating pressure of the stripping analysis tower is -0.05 to -0.08 MPa, and the operating temperature is 70 to 80°C; the operating pressure of the stripping ammonia removal tower is -0.03 to -0.06 MPa, and the operating temperature is 60 to 70°C.

[0008] Furthermore, the anaerobic digestion unit is a mesophilic CSTR reactor; in the material distribution unit, the mass ratio of pretreated kitchen waste and catering waste to sludge mixed in a mixing tank is 1:6.5 to 7.5:13 to 14.

[0009] This invention also provides a method for the synergistic recovery of multiple products from the combined treatment of sludge and kitchen waste, characterized by comprising the following steps: S1. The collection and transportation of kitchen waste, catering waste and sludge are collected and transported separately using negative pressure sealed special vehicles, and the material temperature is monitored in real time during the collection and transportation process. S2. Staged pretreatment: Kitchen waste, catering waste, and sludge are pretreated separately through corresponding pretreatment sub-units. The pretreated kitchen waste has a moisture content of 80-90% and a VSS content of 82-95%. The pretreated catering waste has a moisture content of 85-95% and a VSS content of 90-98%, and crude oil is extracted. The pretreated sludge has a moisture content of 85-95% and a VSS content of 25-35%. S3. Material Distribution and Anaerobic Digestion: The pretreated kitchen waste, catering waste and sludge are mixed through the material distribution unit via a co-processing path and then enter the anaerobic digestion unit for anaerobic digestion, or they are treated separately via a diversion path. After anaerobic digestion, the wastewater is dewatered by centrifugation to obtain biogas slurry and biogas residue. The ammonia nitrogen concentration in the biogas slurry is 800 to 1000 mg / L. S4. Biogas treatment and utilization: The biogas produced by anaerobic digestion is desulfurized and dehydrated by the biogas treatment unit and then stored in a storage tank for use in heating or power generation in the plant area. S5. The biogas slurry multi-product recovery biogas slurry passes through the impurity removal module, the heat transfer module for heating, the hardening removal tower for hardening, and the ammonia recovery module for ammonia removal and concentration. Then it enters the product switching module to produce ammonium bicarbonate or ammonia water according to demand. S6. Biogas residue treatment: Biogas residue is dried, screened and conditioned in a biogas residue treatment unit to produce carbonaceous soil. S7. Kitchen waste recycling: The kitchen waste generated during the pretreatment of catering waste is dried, packaged, and transported out after being processed by the kitchen waste recycling unit.

[0010] Furthermore, in step S2, the hot water hydrolysis temperature of the food waste pretreatment is 80 to 90°C, the operating pressure of the screw press oil extractor is 0.8 to 1.0 MPa, and the crude oil extraction rate is 2.5 to 3.5% with a purity of not less than 95%; in step S3, the anaerobic digestion temperature is 30 to 40°C, and the anaerobic digestion time is 20 to 30 days.

[0011] Furthermore, in step S5, when producing ammonium bicarbonate, the concentrated ammonia gas from the ammonia recovery module is introduced into the carbonization tower, along with CO2 and demineralized water. The reaction occurs at 30 to 40°C to generate an ammonium bicarbonate solution, which is then crystallized at 15 to 20°C and separated by centrifugation to obtain solid ammonium bicarbonate. When producing ammonia water, the concentrated ammonia gas is introduced into the absorption tower and contacted counter-currently with the demineralized water. The liquid-to-gas ratio is controlled at 5 to 8 to 1 to obtain concentrated ammonia water with a concentration of 20 to 25%.

[0012] Furthermore, in step S5, an online ammonia nitrogen concentration detection device is installed at the discharge end of the stripping ammonia removal tower. When the ammonia nitrogen concentration in the effluent is higher than 60 mg / L, the effluent is returned to the heat transfer module for reprocessing; when the ammonia nitrogen concentration does not exceed 60 mg / L, the effluent is sent to the cryocooler for cooling before entering the wastewater treatment system.

[0013] Furthermore, in step S6, the organic matter content of the obtained carbonaceous soil is not less than 30%; in step S7, the moisture content of the dried kitchen waste does not exceed 15%, and the crude protein content is not less than 18%.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention can simultaneously recover six types of high-value products: crude oil, kitchen waste, biogas, carbonaceous soil, ammonia water, and ammonium bicarbonate. It breaks through the limitation of single product in traditional processes and realizes the full exploitation of various valuable components in sludge and kitchen waste.

[0015] 2. On the one hand, the material distribution unit can flexibly switch between collaborative processing and individual diversion. When the composition of a certain material fluctuates or the supply is unstable, the processing path can be adjusted through the diversion valve to avoid the impact of a single material abnormality on the overall process operation. On the other hand, the product switching module of the biogas slurry multi-product recovery unit can switch between the carbonization tower and the absorption tower with one click through the PLC, and produce ammonia water or ammonium bicarbonate as needed according to market conditions, thereby avoiding the economic benefits risk caused by the fluctuation of the market price of a single product and improving the project's risk resistance.

[0016] 3. The graded pretreatment unit is designed with differentiated pretreatment processes for the different characteristics of kitchen waste, catering waste, and sludge. It can accurately remove various interfering substances such as sand, metal, and suspended impurities. Among them, catering waste pretreatment can achieve crude oil extraction of 2.5%-3.5% with a purity of ≥95%. After pretreatment, the VSS content of all materials reaches the optimal range for anaerobic digestion, which not only avoids the clogging and corrosion of downstream anaerobic digestion and ammonia recovery equipment by impurities, but also ensures the quality of products such as carbonaceous soil and kitchen waste.

[0017] 4. The biogas slurry multi-product recovery unit is equipped with a hardening removal tower. By adding 200-300ppm of compound scale inhibitor and using inert material tube bundles, the hardness of the biogas slurry can be reduced to ≤50mg / L, effectively solving the industry pain point of equipment scaling in traditional ammonia recovery processes. The equipment operation cycle is extended by more than 30%, significantly reducing the frequency of equipment cleaning and maintenance, and lowering operation and maintenance costs. At the same time, the online ammonia nitrogen monitoring and reflux mechanism of the stripping ammonia removal tower ensures that the effluent ammonia nitrogen is stable at ≤60mg / L, meeting the influent requirements of the sewage treatment system and avoiding secondary pollution.

[0018] 5. The biogas produced by anaerobic digestion can be used for heating or power generation in the plant area after purification. The waste heat from power generation can be reused in the hydrolysis tank, which can meet more than 60% of the plant's heat demand, achieving energy self-sufficiency and reducing dependence on external energy. At the same time, the entire process adopts a negative pressure closed collection and deodorization device to prevent odor leakage during collection and treatment. Carbon soil can be used for landscaping, and kitchen waste can be used as feed raw material. From source to end, zero discharge of pollutants is achieved, which has significant economic and environmental benefits.

[0019] 6. The system and method of the present invention can flexibly adjust the equipment selection according to the project scale. It is suitable for centralized sludge-kitchen waste treatment centers in large cities, as well as distributed treatment sites in small and medium-sized towns. Moreover, the products can be connected to local agricultural input, energy, feed and other markets, and have great promotion and application value. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process of the present invention; Figure 2 This is a detailed process diagram of the biogas slurry multi-product recovery unit of the present invention. Detailed Implementation

[0021] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0022] like Figure 1 , 2 As shown, the sludge-kitchen waste co-processing multi-product collaborative recycling system provided by the present invention is connected sequentially along the material flow direction to a collection and classification unit, a graded pretreatment unit, a material distribution unit, an anaerobic digestion unit, a biogas treatment unit, a biogas slurry multi-product recycling unit, a biogas residue treatment unit, and a kitchen waste recycling unit. Each unit works collaboratively to complete the disposal and resource recycling of sludge and kitchen waste.

[0023] The collection and sorting unit includes a kitchen waste collection and transportation subunit, a catering waste collection and transportation subunit, and a sludge collection and transportation subunit. Each subunit is equipped with a negative pressure deodorization device and uses a negative pressure sealed special vehicle for material collection and transportation, which can effectively control odor leakage during the collection and transportation process, and at the same time monitor the material temperature in real time to ensure the stability of the material transportation process.

[0024] The graded pretreatment unit is equipped with corresponding pretreatment sub-units for different material characteristics, achieving precise removal of impurities and material quality improvement. The kitchen waste pretreatment sub-unit is equipped with a draining device, crusher, screener, magnetic separator, extrusion dewatering machine, and sand and impurity removal machine sequentially along the material flow direction. This sequentially completes the draining, crushing, screening, iron removal, extrusion dewatering, and sand and impurity removal of kitchen waste, reducing the load on subsequent processing. The catering waste pretreatment sub-unit is equipped with a pulper, sand remover, hot water hydrolysis tank, screw press oil extractor, and impurity removal screen sequentially along the material flow direction. The catering waste is first made into a pulp by the pulper, then sand and gravel impurities are removed by the sand remover before being sent to the hot water hydrolysis tank for hot water hydrolysis. Crude oil is then extracted by the screw press oil extractor, and finally, impurities are further removed by the impurity removal screen. The sludge pretreatment sub-unit is equipped with a sand remover, pulping tank, and stacked press dewatering machine sequentially along the material flow direction. The sludge first enters the sand remover to remove sand and gravel, then enters the pulping tank for pulping treatment, and finally is dewatered and improved by the stacked press dewatering machine.

[0025] The material distribution unit includes a mixing tank diversion valve and a temporary storage bin for kitchen waste. The diversion valve allows for flexible switching between a co-processing path and a diversion path. When the material composition is stable, the pre-treated kitchen waste, catering waste, and sludge are fed into the mixing tank at a set mass ratio and then mixed before entering the subsequent anaerobic digestion unit. When the composition of a certain type of material fluctuates significantly or requires separate treatment, the diversion valve directs it to a separate treatment path, improving the system's adaptability to material fluctuations.

[0026] The anaerobic digestion unit uses a mesophilic CSTR reactor, equipped with a centrifugal dewatering machine and a biogas collection hood. The mesophilic CSTR reactor has the characteristics of high processing efficiency and stable operation, and can realize the efficient anaerobic decomposition of materials. The biogas produced is collected through the biogas collection hood, and the reacted materials are separated into biogas liquid and biogas residue by the centrifugal dewatering machine.

[0027] The biogas treatment unit includes a desulfurization tower, a dehydrator, and a biogas storage tank. The biogas first passes through the desulfurization tower to remove hydrogen sulfide, and then passes through the dehydrator to remove moisture. The purified biogas is stored in the biogas storage tank and can be used for heating or power generation in the plant area, realizing energy recovery and utilization.

[0028] The biogas slurry multi-product recovery unit includes a sequentially connected impurity removal module, heat transfer module, hardening tower, ammonia recovery module, and product switching module, achieving efficient recovery of ammonia nitrogen from the biogas slurry and flexible switching of product types. The impurity removal module uses coagulation and flotation technology to remove suspended impurities from the biogas slurry, ensuring stable operation of subsequent treatment equipment. The heat transfer module uses a heat exchanger to heat the biogas slurry to a set temperature, providing conditions for subsequent ammonia removal treatment. A compound scale inhibitor is added to the hardening tower at a dosage of 200 to 300 ppm to reduce the hardness of the biogas slurry to no more than 50 mg / L (calculated as CaCO3). The tube bundle of the hardening tower is made of inert material or has undergone inert material surface treatment; the inert material can be stainless steel, titanium-titanium alloy, polytetrafluoroethylene, hexagonal boron nitride, ceramic, or glass lining. Fiberglass reinforced plastic or reinforced stainless steel effectively prevents equipment scaling and extends operating cycles; the ammonia recovery module includes a stripping analysis tower, a stripping ammonia removal tower, a condenser, a gas-liquid separator, and an ammonia concentration tower connected in sequence. Ammonia nitrogen is removed from the biogas slurry in the stripping analysis tower and the stripping ammonia removal tower. After separation in the condenser, gas-liquid separator, and concentration in the ammonia concentration tower, high-concentration ammonia gas is obtained; the product switching module includes a carbonization tower and an absorption tower set in parallel, which can be switched with one button through a PLC control system, and can flexibly produce ammonium bicarbonate or ammonia water according to market demand.

[0029] The biogas residue treatment unit includes a low-temperature dryer, a screening machine, and a carbon soil conditioning tank. The biogas residue first enters the low-temperature dryer to dry to the set moisture content, then passes through the screening machine to remove impurities, and finally enters the carbon soil conditioning tank for conditioning treatment to produce carbon soil that meets the standards and can be used in landscaping and other fields.

[0030] The food waste recycling unit includes a dryer and a baler. The food waste generated during the pretreatment of catering waste enters the dryer and is dried to a set moisture content. Then, it is baled by the baler for easy transport and utilization as feed raw material.

[0031] This invention also provides a method for the synergistic recovery of multiple products from the combined treatment of sludge and kitchen waste. This method is based on the above-mentioned system and specifically includes the following steps: S1 Collection and Classification: Kitchen waste, catering waste and sludge are collected separately using negative pressure sealed special vehicles. During the collection process, the temperature of the materials is monitored in real time by temperature sensors to prevent the materials from deteriorating due to abnormal temperature.

[0032] S2 graded pretreatment: Kitchen waste is sent to the kitchen waste pretreatment subunit, where it passes through a draining device, a crushing and screening machine, a magnetic separator to remove metal impurities, an extrusion dewatering machine, a sand and impurity removal machine, and a dewatering and sand removal machine. After pretreatment, the kitchen waste has a moisture content of 80-90% and a VSS content of 82-95%. Catering waste is sent to the catering waste pretreatment subunit, where it passes through a pulping machine, a sand removal machine, a hot hydrolysis tank, a screw press for oil extraction, and a screen for impurity removal. The hydrolysis temperature is controlled at 80 to 90℃, the operating pressure of the screw press oil extractor is 0.8 to 1.0 MPa, and the moisture content of the pretreated catering waste is 85 to 95%, the VSS content is 90 to 98%, and the crude oil extraction rate is 2.5 to 3.5% with a purity of not less than 95%. The sludge is sent to the sludge pretreatment subunit, and then dewatered by passing through the sand removal tank, sand removal slurry tank, slurry stacking press dewatering machine in sequence. The moisture content of the pretreated sludge is 85 to 95%, and the VSS content is 25 to 35%.

[0033] S3 Material Distribution and Anaerobic Digestion: The processing path is selected through the diversion valve of the material distribution unit. In the co-processing path, pretreated kitchen waste, catering waste and sludge are fed into the mixing tank at a mass ratio of 1:6.5 to 7.5:13 to 14 and mixed evenly before entering the mesophilic CSTR reactor for anaerobic digestion. The digestion temperature is controlled at 30 to 40°C and the digestion time is 20 to 30 days. In the diversion path, a certain type of material is introduced into the processing flow separately through the diversion valve. The biogas produced during anaerobic digestion is collected through a biogas collection hood. The reacted materials are separated into biogas slurry and biogas residue by a centrifugal dewatering machine. The ammonia nitrogen concentration in the biogas slurry is 800 to 1000 mg / L.

[0034] S4 Biogas Treatment and Utilization: After biogas is collected, it is sent to the biogas treatment unit. First, hydrogen sulfide is removed by the desulfurization tower, and then water is removed by the dehydrator. The purified biogas is stored in the biogas storage tank and can be transported to the plant heating system for heating or connected to the generator for power generation. The waste heat from power generation can be reused in the hot water hydrolysis tank to improve energy utilization.

[0035] S5 biogas slurry multi-product recovery: The biogas slurry first enters the impurity removal module, where suspended impurities are removed by coagulation and flotation processes. It then enters the heat transfer module, where it is heated to 75-85℃ and the pH is adjusted to 9-10. Subsequently, it is sent to the hardening removal tower for hardening treatment, where a compound scale inhibitor is added to prevent scaling. The hardened biogas slurry then enters the ammonia recovery module, where it undergoes ammonia removal and concentration in sequence via a stripping stripping tower, ammonia stripping deammonia removal tower, a condenser, a gas-liquid separator, and an ammonia concentration tower. The stripping stripping tower operates at a pressure of -0.05 to -0.08 MPa and a temperature of 70-80℃, while the stripping deammonia removal tower operates at a pressure of -0.03 to -0.06 MPa and a temperature of 60-70℃. The concentrated ammonia then enters the product... In the material switching module, when producing ammonium bicarbonate, ammonia gas is introduced into the carbonation tower, along with CO2 and demineralized water. The reaction occurs at 30 to 40°C to generate an ammonium bicarbonate solution, which is then crystallized at 15 to 20°C and separated by centrifugation to obtain solid ammonium bicarbonate. When producing ammonia water, ammonia gas is introduced into the absorption tower and comes into countercurrent contact with the demineralized water. The liquid-to-gas ratio is controlled at 5 to 8 to 1 to produce concentrated ammonia water with a concentration of 20 to 25%. An online ammonia nitrogen concentration detection device is installed at the discharge end of the stripping ammonia removal tower. When the ammonia nitrogen concentration in the effluent is higher than 60 mg / L, the effluent is returned to the heat transfer module for reprocessing. When the ammonia nitrogen concentration does not exceed 60 mg / L, the effluent is sent to the cryocooler for cooling before entering the wastewater treatment system.

[0036] S6 biogas residue treatment: The biogas residue is sent to the biogas residue treatment unit, first dried to a moisture content of 40 to 45% by a low-temperature dryer, then screened to remove undecomposed impurities, and finally enters the carbon soil conditioning tank, where a conditioning agent is added for conditioning treatment to obtain carbon soil. The organic matter content of the carbon soil is not less than 30%, which meets the GB / T23486-2009 standard.

[0037] S7 Food Waste Recycling: Food waste generated during the pretreatment of catering waste is sent to the food waste recycling unit, dried by a dryer until the moisture content does not exceed 15%, and then packaged by a baler. The crude protein content of the packaged food waste is not less than 18%, which meets the hygiene standards for feed raw materials, and then transported for resource utilization.

[0038] This invention achieves classified and sealed collection and transportation of sludge and kitchen waste through a collection and classification unit, avoiding secondary pollution during transportation; a graded pretreatment unit performs precise pretreatment based on the characteristics of different materials, removing impurities and extracting crude oil to improve material quality; a material distribution unit can flexibly switch between collaborative and diversion paths to adapt to different material compositions; an anaerobic digestion unit achieves efficient anaerobic decomposition of materials under mesophilic conditions to produce biogas; a biogas treatment unit purifies and recovers biogas for energy reuse; a biogas slurry multi-product recovery unit achieves on-demand production of ammonia water and ammonium bicarbonate through impurity removal, hardening removal, ammonia removal, concentration, and product switching; a biogas residue treatment unit converts biogas residue into carbonaceous soil, and a kitchen waste residue recovery unit converts kitchen waste into feed raw materials, ultimately realizing the full-chain resource utilization of sludge and kitchen waste, simultaneously recovering six products: crude oil, kitchen waste residue, biogas, carbonaceous soil, ammonia water, and ammonium bicarbonate, thus improving the resource recovery rate.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A sludge-kitchen combined disposal multi-product synergic recovery system, characterized in that, The kitchen waste pretreatment subunit is sequentially provided with a draining device, a crushing and screening machine, a magnetic separator, a squeezing dehydrator and a sand removal and impurity removal machine along the material flow direction; the catering waste pretreatment subunit is sequentially provided with a pulping machine, a sand removal machine, a hot hydrolysis tank, a screw press oil extractor and an impurity removal sieve along the material flow direction; and the sludge pretreatment subunit is sequentially provided with a sand removal tank, a pulping pool and a laminated press dehydrator along the material flow direction.

2. The sludge-kitchen combined disposal multi-product synergic recovery system of claim 1, wherein, The hard removal tower is internally added with a compound scale inhibitor, and the addition amount is 200-300 ppm, so that the hardness of the biogas slurry is reduced to not more than 50 mg / L in terms of CaCO3; and the pipe bundle of the hard removal tower is made of inert materials or is surface treated by inert materials, and the inert materials are one or more of stainless steel, titanium alloy, polytetrafluoroethylene, hexagonal boron nitride ceramic, glass lining, glass fiber reinforced plastic or reinforced stainless steel.

3. The sludge-kitchen combined disposal multi-product synergic recovery system of claim 1, wherein, The operating pressure of the stripping and resolving tower is -0.05 to -0.08 MPa, and the operating temperature is 70-80℃; the operating pressure of the stripping and deaminating tower is -0.03 to -0.06 MPa, and the operating temperature is 60-70℃.

4. The sludge-kitchen combined disposal multi-product cogeneration recovery system of claim 1, wherein, The anaerobic digestion unit is a mesophilic CSTR reactor; in the material distribution unit, the mass ratio of pretreated kitchen waste, catering waste and sludge mixed by the mixing tank is 1:6.5-7.5:13-14.

5. The sludge-kitchen combined disposal multi-product synergic recovery system of claim 1, wherein, The following steps are included:

6. A sludge-kitchen waste co-treatment multi-product synergistic recovery process characterized by, S1, kitchen waste, catering waste and sludge are respectively collected and transported by negative pressure closed special vehicles, and the material temperature is monitored in real time during the collection and transportation process; S2, the kitchen waste, the catering waste and the sludge are respectively pretreated by the corresponding pretreatment subunit, the water content of the pretreated kitchen waste is 80-90%, the VSS content is 82-95%, the water content of the pretreated catering waste is 85-95%, the VSS content is 90-98%, and the crude oil is extracted, and the water content of the pretreated sludge is 85-95%, the VSS content is 25-35%; ​ S3, the pretreated kitchen waste and sludge are mixed by the material distribution unit and then enter the anaerobic digestion unit for anaerobic digestion, or are separately treated by selecting a separate path, and the biogas produced by the anaerobic digestion is centrifuged to obtain biogas slurry and biogas residue, and the ammonia nitrogen concentration in the biogas slurry is 800 to 1000 mg / L; S4, the biogas produced by the anaerobic digestion is desulfurized and dewatered by the biogas treatment unit and then is stored in a storage tank for heating or power generation in the factory area; S5, the biogas slurry is sequentially subjected to impurity removal by the impurity removal module, heating by the heat transfer module, hardness removal by the hardness removal tower, ammonia removal and concentration by the ammonia recovery module, and then enters the product switching module to produce ammonium bicarbonate or ammonia water according to the demand; S6, the biogas residue is dried, screened and conditioned by the biogas residue treatment unit to produce carbon soil; S7, the kitchen residue produced in the pretreatment process of the kitchen waste is dried by the kitchen residue recovery unit and then is packaged and shipped out.

7. The sludge-kitchen combined disposal multi-product synergic recovery method according to claim 6, characterized in that, In step S2, the hydrolysis temperature of the kitchen waste is 80 to 90℃, the operating pressure of the screw press oil extractor is 0.8 to 1.0 MPa, the oil extraction rate of the crude oil is 2.5 to 3.5%, and the purity is not less than 95%; in step S3, the temperature of the anaerobic digestion is 30 to 40℃, and the anaerobic digestion time is 20 to 30 days.

8. The sludge-kitchen waste co-disposal multi-product cogeneration recovery process of claim 6 wherein, In step S5, when ammonium bicarbonate is produced, the ammonia gas after concentration by the ammonia recovery module is introduced into the carbonation tower, CO2 and desalted water are introduced at the same time, and ammonium bicarbonate solution is generated by reaction at 30 to 40℃, followed by crystallization at 15 to 20℃, and ammonium bicarbonate solid is obtained by centrifugal separation; When ammonia water is produced, the concentrated ammonia gas is introduced into the absorption tower and is in counterflow contact with the desalted water, the liquid-gas ratio is controlled to be 5 to 8 to 1, and 20 to 25% concentrated ammonia water is prepared.

9. The sludge-kitchen combined disposal multi-product synergic recovery method according to claim 6, characterized in that, In step S5, an online ammonia nitrogen concentration detection device is arranged at the discharge end of the stripping ammonia removal tower, when the ammonia nitrogen concentration in the effluent is higher than 60 mg / L, the effluent is returned to the heat transfer module for reprocessing; when the ammonia nitrogen concentration is not more than 60 mg / L, the effluent is sent to the cryogenic cooler for cooling and then enters the sewage treatment system.

10. The sludge-kitchen combined disposal multi-product synergic recovery method according to claim 6, characterized in that, In step S6, the organic matter content of the prepared carbon soil is not less than 30%; in step S7, the water content of the dried kitchen residue is not more than 15%, and the crude protein content is not less than 18%.

Images