System and method for co-combustion of oily sludge
By designing an oily sludge co-firing system, the synergistic treatment of oily sludge with different morphologies was achieved, solving the problems of high cost and low efficiency in existing oily sludge treatment technologies, and realizing the efficient utilization and harmless disposal of oily sludge.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUANENG YANTAI BAJIAO THERMOELECTRIC CO LTD
- Filing Date
- 2023-09-21
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies for treating oily sludge have problems such as high oil content in solid residues, high treatment costs, and unsuitability for large-scale application. In particular, centrifugal separation and distillation separation technologies cannot meet the requirements for harmless disposal, and pyrolysis methods have high energy consumption and large investment.
Design a co-firing system for oily sludge, including a sludge storage silo, a crushing device, a pretreatment device, a conveying mechanism, and a boiler. Through crushing, screening, centrifugation, drying, and co-firing, the system achieves the synergistic treatment of oily sludge with different morphologies. The system utilizes the flue gas from the boiler combustion for purification, thereby improving the utilization rate of the oily sludge.
It achieves efficient utilization of oil sludge, reduces treatment costs, improves treatment results, meets the requirements for harmless disposal, and is suitable for large-scale application.
Smart Images
Figure CN117249440B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of oily sludge treatment, and more particularly to a co-firing system and method for oily sludge. Background Technology
[0002] Oily sludge, including both landed and transported oily sludge, is one of the most significant solid wastes generated during oil and gas well production in the petroleum and petrochemical industry. Containing a mixture of crude oil, refined oil, silt, minerals, diesel oil, white oil, waxy oil, asphalt, and rock fragments, it cannot be directly recycled. During storage, transportation, and treatment, it causes severe pollution to soil, groundwater, and rivers, becoming a major pain point and challenge for the petrochemical industry. Current oily sludge treatment technologies include centrifugal separation, pyrolysis separation, and distillation separation. However, centrifugal and distillation separations often result in high oil content in the solid residue, typically exceeding 2%, falling short of the required 0.3%. Further processing is necessary for the harmless disposal of oily sludge. Pyrolysis and distillation methods are immature, energy-intensive, require large investments, and have poor technological and economic prospects, making them unsuitable for large-scale oily sludge treatment. Therefore, achieving more economical and harmless, resource-efficient disposal of oily sludge remains a major technical challenge for the petrochemical industry. Summary of the Invention
[0003] The present invention aims to at least partially solve one of the technical problems in the related art.
[0004] Therefore, embodiments of the present invention propose a co-firing system for oily sludge, which has the advantages of high oil sludge utilization rate and synergistic treatment of oil sludge with different morphologies.
[0005] According to an embodiment of the present invention, an oily sludge co-firing system includes a sludge storage silo, a crushing device, a pretreatment device, a conveying mechanism, and a boiler. The sludge storage silo includes a first silo and a second silo. The crushing device is connected to the first silo. A screening mechanism is connected to the inlet of the crushing device to re-crush large particles of oily sludge. The pretreatment device is connected to the second silo to initially separate the oily sludge. A centrifuge is connected to the outlet of the pretreatment device to separate the oily sludge. The solid phase outlet of the centrifuge is connected to a drying device. The conveying mechanism is connected to the outlet of the screening mechanism and the outlet of the drying device. The outlet of the conveying mechanism is connected to a coal mill. The inlet of the boiler is connected to the outlet of the coal mill. The flue gas outlet of the boiler is connected to a flue gas treatment device.
[0006] The oily sludge co-firing system according to embodiments of the present invention has the advantages of high oily sludge utilization and synergistic treatment of oily sludge with different morphologies. This application synergistically treats and co-firs two types of oily sludge with different morphologies, resulting in a diverse range of treated oily sludge types and good treatment effects.
[0007] In some embodiments, the screening mechanism includes a multi-layer screen.
[0008] In some embodiments, the conveying device includes a first conveyor belt and a second conveyor belt, the first conveyor belt conveying the undersize material from the screening mechanism to the second conveyor belt, and the second conveyor belt conveying the coal lumps and undersize material to the coal mill.
[0009] In some embodiments, the centrifuge is connected to a wastewater treatment plant and an oily wastewater treatment plant to process the oil and water products obtained from separating oily sludge, respectively.
[0010] In some embodiments, the drying apparatus is connected to the secondary air blower or air preheater of the boiler.
[0011] In some embodiments, a centrifugal pump is provided at the bottom of the first chamber to transport sludge.
[0012] In some embodiments, the pretreatment apparatus includes an apparatus body and a stirrer, the apparatus body being provided with a dosing device, and the stirrer being located at the bottom of the apparatus body.
[0013] According to an embodiment of the present invention, the method for co-firing oily sludge includes the following steps:
[0014] The oily sludge in the first compartment of the sludge storage silo is transported to the crushing device for crushing. After crushing, it is sent to the screening mechanism for screening. The qualified undersize material is transported to the coal mill by the conveying mechanism, and the oversize material in the screening mechanism is sent to the crushing mechanism for re-crushing.
[0015] The oily sludge in the second compartment of the sludge storage silo is transported to the pretreatment unit, where demulsifier and cleaning agent are added and the oily sludge is thoroughly mixed with the demulsifier and cleaning agent.
[0016] The oil sludge after pretreatment is transported to a centrifuge for centrifugation to separate oil, water and solids. The oil is sent to the sludge treatment station, the water is sent to the wastewater treatment station, and the solids are sent to the drying unit for drying.
[0017] The conveying device mixes the undersize material, solid material and coal lumps and feeds them into the coal mill, which grinds the coal to obtain particles of the target size.
[0018] The target particle size particles are fed into the boiler for combustion, and the flue gas after combustion is purified by a flue gas treatment device.
[0019] In some embodiments, the sludge in the first chamber is ground-borne sludge, and the sludge in the second chamber is stored and transported sludge.
[0020] In some embodiments, the target particle size is conveyed into the boiler by wind power. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of the co-firing system for oily sludge according to an embodiment of the present invention.
[0022] Reference numerals: 1. First chamber; 2. Crushing device; 3. Screening mechanism; 4. First conveyor belt; 5. Second chamber; 6. Pretreatment device; 7. Centrifuge; 8. Drying device; 9. Second conveyor belt; 10. Coal mill; 11. Boiler; 12. Flue gas treatment device. Detailed Implementation
[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0024] Ground-borne sludge is formed during oilfield development, especially during oil well production and downhole operations, when some crude oil is released or carried to the surface by tubing, sucker rods, pumps, and other downhole tools, and then seeps into the soil. Storage and transportation sludge is formed during oil storage and transportation when inorganic matter and heavy oil components such as asphaltene and paraffin naturally settle under gravity and accumulate at the bottom of crude oil storage tanks, forming a black, thick, gelatinous sludge that occupies a large storage space. Ground-borne sludge has a low oil content (5-10%) and water content (5-10%), but a high solids content (80-90%); while storage and transportation sludge has a low oil content (15-25%) and water content (65-75%), but a very low solids content (5-10%).
[0025] According to an embodiment of the present invention, the oily sludge co-firing system includes a sludge storage silo, a crushing device 2, a pretreatment device 6, a conveying mechanism, and a boiler 11. The sludge storage silo includes a first silo 1 and a second silo 5. The crushing device 2 is connected to the first silo 1. The screening mechanism 3 is connected to the inlet of the crushing device 2 to re-crush large particles of oily sludge. The pretreatment device 6 is connected to the second silo 5 to initially separate the oily sludge. The centrifuge 7 is connected to the outlet of the pretreatment device 6 to separate the oily sludge. The solid phase outlet of the centrifuge 7 is connected to a drying device 8. The conveying mechanism is connected to the outlet of the screening mechanism 3 and the outlet of the drying device 8. The outlet of the conveying mechanism is connected to a coal mill 10. The inlet of the boiler 11 is connected to the outlet of the coal mill 10. The flue gas outlet of the boiler 11 is connected to a flue gas treatment device 12. First compartment 1 and second compartment 5 are filled with ground oil sludge and storage and transportation oil sludge, respectively. First compartment 1 is treated by direct crushing, screening and then co-firing, while second compartment 5 is treated by pretreatment, centrifugal drying and then co-firing. The two compartments are treated according to the properties of the oil sludge, and the components in the oil sludge are fully utilized before co-firing, which improves the utilization rate of oil sludge.
[0026] The oily sludge co-firing system according to embodiments of the present invention has the advantages and technical effects brought about by the independent claims.
[0027] In some embodiments, the screening mechanism 3 includes a multi-layer screen.
[0028] The multi-layer screen can thoroughly separate the crushed oil sludge particles, ensuring that particles of the target size are adequately screened. The screening machine uses a linear screen.
[0029] In some embodiments, the conveying device includes a first conveyor belt 4 and a second conveyor belt 9. The first conveyor belt 4 conveys the undersize material from the screening mechanism 3 to the second conveyor belt 9, and the second conveyor belt 9 conveys the coal lumps and undersize material to the coal mill 10.
[0030] Specifically, the first transmission belt and the second conveyor belt 9 work together to transport the screened undersize material and the dried solid material. The first conveyor belt 4 transports the screened undersize material and the dried solid material to the second conveyor belt 9, which then mixes the raw coal lumps and transports them to the coal mill 10. Inside the coal mill 10, the materials are mixed, stirred, and crushed to produce particles of a specific size.
[0031] In some embodiments, centrifuge 7 is connected to a wastewater treatment plant and an oily wastewater treatment plant to process the oil and water products obtained from separating sludge, respectively.
[0032] Specifically, the wastewater treatment plant processes the wastewater separated by centrifuge 7, and the sludge treatment plant processes the sludge separated by centrifuge 7. Classifying and processing the stored and transported oil sludge can improve the co-firing effect of the solids in the oil sludge.
[0033] In some embodiments, the drying apparatus 8 is connected to the secondary air blower or air preheater of the boiler 11.
[0034] Specifically, the drying device 8 uses the waste heat of the secondary air from the boiler 11 for drying, reducing the cost of drying sludge. The boiler 11 is a coal-fired boiler. The secondary air blower sends secondary air into the drying device 8 or sends air to the drying device 8 through an air preheater, thus reducing the cost of sludge treatment.
[0035] In some embodiments, a centrifugal pump is provided at the bottom of the first chamber 1 to transport sludge.
[0036] Specifically, the centrifugal pump installed at the bottom of the first compartment 1 can ensure the conveying efficiency of the oil sludge, so that the oil sludge that falls to the ground can be quickly sent into the crushing device 2 for crushing.
[0037] In some embodiments, the pretreatment device 6 includes a device body and a stirrer, the device body being provided with a dosing device and the stirrer being located at the bottom of the device body.
[0038] Specifically, the bottom of the device is equipped with a stirrer to thoroughly mix the sludge with the demulsifier and the cleaning agent. The dosing components include two chemical storage tanks and a chemical dosing pipe, which is connected to the top of the device.
[0039] According to an embodiment of the present invention, the method for co-firing oily sludge includes the following steps:
[0040] The oily sludge in the first compartment 1 of the sludge storage silo is transported to the crushing device 2 for crushing. After crushing, it is sent to the screening mechanism 3 for screening. The qualified undersize material is transported to the coal mill 10 by the conveying mechanism, and the oversize material in the screening mechanism 3 is sent to the crushing mechanism for re-crushing.
[0041] The oily sludge in the second compartment 5 of the sludge storage silo is transported to the pretreatment unit 6, and demulsifier and cleaning agent are added to the pretreatment unit 6. The oily sludge is thoroughly mixed with the demulsifier and cleaning agent.
[0042] The oil sludge treated by the pretreatment device 6 is transported to the centrifuge 7 for centrifugation to separate oil, water and solids. The oil is sent to the waste oil treatment station, the water is sent to the wastewater treatment station, and the solids are sent to the drying treatment device 8 for drying.
[0043] The conveying device mixes the undersize material, solid material and coal lumps and feeds them into the coal mill 10, where the coal mill 10 grinds the material to obtain particles of the target size.
[0044] The target particle size particles are fed into boiler 11 for combustion, and the flue gas after combustion is purified by flue gas treatment device 12.
[0045] In some embodiments, the sludge in the first compartment 1 is ground-borne sludge, and the sludge in the second compartment 5 is storage and transportation sludge. The ground-borne sludge in the first compartment 1 has poor fluidity and high solids content, and can be directly crushed and utilized, while the storage and transportation sludge in the second compartment 5 has low solids content and needs to be centrifuged and separated for separate utilization.
[0046] In some embodiments, the target particle size is conveyed into the boiler 11 by wind power.
[0047] Specifically, the mixture of oil sludge and coal, after being blended with coal lumps and ground into particles of the target size, is conveyed into boiler 11 by wind power, resulting in good combustion performance and convenient wind power delivery. The solid residue after combustion can be utilized as a resource.
[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0052] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.
Claims
1. A co-firing system for oily sludge, characterized in that, include: The sludge storage silo includes a first silo and a second silo, wherein the sludge in the first silo is ground-borne sludge and the sludge in the second silo is stored and transported sludge. A crushing device is connected to the first chamber, and a screening mechanism is connected to the inlet of the crushing device to re-crush large particles of sludge. A pretreatment device is connected to the second chamber to initially separate the sludge, a centrifuge is connected to the outlet of the pretreatment device to separate the sludge, and the solid phase outlet of the centrifuge is connected to a drying device. A conveying mechanism is connected to the outlet of the screening mechanism and the outlet of the drying device, and the outlet of the conveying mechanism is connected to the coal mill. The boiler has its inlet connected to the outlet of the coal mill, and its flue gas outlet connected to a flue gas treatment device. The drying device is connected to the secondary air blower or air preheater of the boiler.
2. The co-firing system for oily sludge according to claim 1, characterized in that, The screening mechanism includes a multi-layer screen.
3. The co-firing system for oily sludge according to claim 1, characterized in that, The conveying mechanism includes a first conveyor belt and a second conveyor belt. The first conveyor belt conveys the undersize material from the screening mechanism to the second conveyor belt, and the second conveyor belt conveys the coal lumps and undersize material to the coal mill.
4. The co-firing system for oily sludge according to claim 1, characterized in that, The centrifuge is connected to the wastewater treatment plant and the oily wastewater treatment plant to process the oil and water products obtained from the separation of oily sludge, respectively.
5. The co-firing system for oily sludge according to claim 1, characterized in that, A centrifugal pump is installed at the bottom of the first compartment to transport oil sludge.
6. The co-firing system for oily sludge according to claim 1, characterized in that, The pretreatment device includes a device body and a stirrer. The device body is equipped with a dosing device, and the stirrer is located at the bottom of the device body.
7. A method for co-firing oily sludge, implemented using the oily sludge co-firing system as described in any one of claims 1-6, characterized in that, Includes the following steps: The oily sludge in the first compartment of the sludge storage silo is transported to the crushing device for crushing. After crushing, it is sent to the screening mechanism for screening. The qualified undersize material is transported to the coal mill by the conveying mechanism, and the oversize material in the screening mechanism is sent to the crushing mechanism for re-crushing. The oily sludge in the second compartment of the sludge storage silo is transported to the pretreatment unit, where demulsifier and cleaning agent are added and the oily sludge is thoroughly mixed with the demulsifier and cleaning agent. The oil sludge after pretreatment is transported to a centrifuge for centrifugation to separate oil, water and solids. The oil is sent to the sludge treatment station, the water is sent to the wastewater treatment station, and the solids are sent to the drying unit for drying. The conveying device mixes the undersize material, solid material and coal lumps and feeds them into the coal mill, which grinds the coal to obtain particles of the target size. The target particle size particles are fed into the boiler for combustion, and the flue gas after combustion is purified by a flue gas treatment device.
8. The method for co-firing oily sludge according to claim 7, characterized in that, The target particle size is conveyed into the boiler by wind power.