Oil sludge treatment method and system

Abstract

The present application discloses an oil sludge treatment method and system, wherein the oil sludge treatment method comprises: drying the oil sludge and mixing it with an extraction solvent to obtain a first mixture; extracting and separating the first mixture to obtain oil sludge residue and an oil-containing gas phase mixture; subjecting the oil sludge residue, superheated steam and a first oxidant to a pyrolysis and gasification reaction to obtain gasified oil gas and gasified residue; subjecting at least part of the oil-containing gas phase mixture to an oil-gas separation to obtain gasified gas; combusting the gasified gas with a second oxidant, and using the heat generated by the combustion to melt the gasified residue to obtain molten slag and hot flue gas. The oil sludge treatment method of the present application not only solves the problem of low pyrolysis oil yield caused by traditional oil sludge pyrolysis, but also realizes the green and harmless treatment of pyrolysis residue, thereby realizing the green disposal and energy utilization of oil-containing sludge throughout the process.

Description

Technical Field

[0001] The present application belongs to the technical field of oil-containing solid waste treatment, and in particular, relates to an oil sludge treatment method and system. Background Art

[0002] Oil sludge is an oily solid waste generated during the oilfield drilling, transportation, refining and oily wastewater treatment. Generally speaking, oil sludge has a high oil content (10%-50%), a water content of 50%-90%, a high viscosity, and is difficult to dehydrate. It is a black, viscous semi-fluid. The composition of oily sludge not only contains a large amount of aged crude oil, asphaltene, wax, colloid, bacteria, suspended solids, salts, corrosive products, acidic gases and excessive chemical heavy metals (such as copper, zinc, chromium, mercury, etc.), but also includes corrosion inhibitors, coagulants, bactericides, scale inhibitors and other water treatment agents added during the production process. If these harmful substances are not effectively and timely treated, they will cause serious harm and corrosion to the surrounding crop soil cultivation, water bodies, air, ecological environment, etc. Therefore, oil sludge has been included in the national hazardous waste list of my country, and corresponding environmental protection standards have also been formulated for oil sludge disposal (such as landfill, pyrolysis, incineration, etc.).

[0003] At present, the actual production process of oil sludge treatment generally adopts pyrolysis method. The so-called pyrolysis method refers to sending the oily sludge to the pyrolysis furnace for heating treatment under the condition of inert atmosphere and slight positive pressure, and then separating it into pyrolysis residue, pyrolysis liquid and pyrolysis gas, so as to achieve resource utilization of oily sludge. However, directly drying the oil sludge and then pyrolyzing it will easily cause the oil phase in the oil sludge to decompose into pyrolysis gas and pyrolysis carbon due to heat, which will affect the yield of oil products from pyrolysis of the oil sludge. At the same time, the oil sludge residue produced as hazardous waste needs to be treated separately in an additional melting combustion furnace.

[0004] Therefore, there is an urgent need for an oil sludge treatment technology that can overcome the defect of low pyrolysis oil yield caused by traditional oil sludge pyrolysis, and at the same time achieve green and harmless treatment of oily sludge. Summary of the invention

[0005] In view of this, one purpose of the present application is to provide a method for treating oil sludge, which mixes the oil sludge with an extraction solvent and then sequentially performs extraction separation, pyrolysis gasification and melt combustion treatment, which not only solves the problem of low pyrolysis oil yield caused by traditional oil sludge pyrolysis, but also can achieve green and harmless treatment of pyrolysis residue, thereby realizing green disposal and energy utilization of oil-containing sludge throughout the process.

[0006] Another object of the present application is to provide an oil sludge processing system.

[0007] To achieve the above-mentioned purpose, the first aspect of the present application proposes a method for treating oil sludge, comprising:

[0008] drying the oil sludge and mixing it with an extraction solvent to obtain a first mixture;

[0009] Extracting and separating the first mixture to obtain oil sludge and an oil-containing gas phase mixture;

[0010] The oil sludge, superheated steam and a first oxidant are subjected to pyrolysis and gasification reaction to obtain gasified oil gas and gasified slag;

[0011] separating oil and gas from at least a portion of the oil-gas phase mixture to obtain gasified gas;

[0012] The fuel gas is burned with a second oxidant, and the heat generated by the combustion is used to melt the gasified slag to obtain molten slag and hot flue gas; the fuel gas includes the gasification gas.

[0013] In some embodiments, the oil sludge treatment method further includes: during the extraction and separation process, indirectly or directly exchanging heat between the vaporized oil gas and the first mixture.

[0014] In some embodiments, the oil-containing gas-phase mixture includes a first oil-containing gas-phase mixture and a second oil-containing gas-phase mixture, the first oil-containing gas-phase mixture includes tar, and the second oil-containing gas-phase mixture includes the extraction solvent and light oil.

[0015] In some embodiments, when the vaporized oil and gas are indirectly heat exchanged with the first mixture, the separation of oil and gas from at least a portion of the oil-containing gas phase mixture comprises:

[0016] The first oil-gas phase mixture is subjected to the oil-gas separation to obtain the gasified gas and the first liquid phase; the first liquid phase includes tar;

[0017] In some embodiments, when the vaporized oil and gas are directly heat exchanged with the first mixture, the separation of oil and gas from at least a portion of the oil-containing gas phase mixture comprises:

[0018] The oil-gas mixture is subjected to the oil-gas separation to obtain the gasified gas and the second liquid phase; the second liquid phase is the extraction solvent, light oil and tar.

[0019] In some embodiments, the oil sludge treatment method further comprises:

[0020] fractionally distilling the mixture of the first liquid phase and the second oil-containing gas phase to obtain recovered extraction solvent, light oil, water and heavy oil;

[0021] The recovered extraction solvent is reused in the mixing process.

[0022] In some embodiments, the second liquid phase is fractionally distilled to obtain the extraction solvent, light oil, water and heavy oil;

[0023] The recovered extraction solvent is reused in the mixing process.

[0024] In some embodiments, the first oxidant and the second oxidant both include preheated air.

[0025] In some embodiments, the fuel gas further comprises combustion gas.

[0026] In some embodiments, the oil sludge treatment method further comprises:

[0027] Performing a first heat exchange between the hot flue gas and water to obtain the superheated steam and the hot flue gas after a first cooling;

[0028] Exchanging heat between the first cooled hot flue gas and air to obtain the preheated air and the second cooled hot flue gas;

[0029] The second cooled hot flue gas is used as the drying gas for drying.

[0030] In some embodiments, the drying temperature is 200-250°C.

[0031] In some embodiments, in the first mixture, the mass ratio of the dried sludge to the extraction solvent is 1:(1-2).

[0032] In some embodiments, the extraction solvent includes at least one of light coal tar, benzene, and toluene.

[0033] In some embodiments, the temperature of the vaporized oil gas is 700-800°C.

[0034] In some embodiments, the extraction and separation time is 2-4 minutes.

[0035] In some embodiments, the mass ratio of the oil sludge, superheated steam and the first oxidant is (0.8-1.0):(0.48-1.2):(0.1-0.6).

[0036] In some embodiments, the reaction temperature of the pyrolysis and gasification is 800-850° C., and the reaction time of the pyrolysis and gasification is 3-10 min.

[0037] In some embodiments, the melting temperature is 1300-1500° C., and the melting time is 0.5-1.0 h.

[0038] In some embodiments, the composition of the gasified slag includes: combustibles with poor gasification reactivity and inert ash, etc.

[0039] In some embodiments, the oil sludge residue comprises: combustibles and inert ash, etc.

[0040] In some embodiments, the gasification gas comprises carbon monoxide, carbon dioxide, hydrogen, methane and the like.

[0041] In some embodiments, the method of mixing the dried sludge with the extraction solvent includes stirring mixing or ultrasonic dispersion.

[0042] The second aspect of the present application provides an oil sludge treatment system, comprising:

[0043] A drying unit, used for drying the oil sludge;

[0044] a mixing unit connected to the drying unit and an extraction solvent source to mix the dried sludge with the extraction solvent to obtain a first mixture;

[0045] An extraction and separation unit, the extraction and separation unit is connected to the mixing unit to extract and separate the first mixture to obtain oil sludge and oil-containing gas phase mixture;

[0046] A pyrolysis and gasification unit, the pyrolysis and gasification unit is connected to the extraction and separation unit and is used to pyrolyze and gasify the oil sludge to obtain gasified oil gas and gasified slag;

[0047] A melting combustion unit is connected to the pyrolysis gasification unit, and is used to subject the gasified slag to a melting combustion process to obtain molten slag and hot flue gas.

[0048] In some embodiments, the extraction and separation unit includes a first shell, the top of the first shell is provided with a first inlet for the first mixture to enter the first shell, the bottom of the first shell is provided with a first outlet for the oil sludge to be discharged, and a plurality of inclined plates are spaced apart on opposite sides of the first shell, and the angle between two adjacent inclined plates is an acute angle.

[0049] In some embodiments, the oil sludge treatment system further comprises an oil-gas separation unit, wherein the oil-gas separation unit is connected to the extraction separation unit, the molten combustion unit and the fractional distillation unit, and the fractional distillation unit is connected to the mixing unit.

[0050] In some embodiments, the oil sludge treatment system further comprises a waste heat recovery unit, and a cold side of the waste heat recovery unit is connected to a water source and a pyrolysis gasification unit.

[0051] In some embodiments, the pyrolysis gasification unit and the melt combustion unit are separately provided or integrally formed.

[0052] In some embodiments, a second inlet for the vaporized oil gas to enter the first shell is provided at the lower end of the first shell, and a second outlet is provided at the upper end of the first shell.

[0053] In some embodiments, the extraction and separation unit also includes a second shell, which is sleeved on the outside of the first shell, and the inner wall of the second shell and the outer wall of the first shell form an annular closed space; the lower end of the second shell is provided with a second inlet for the vaporized oil and gas to enter the first shell, the upper end of the second shell is provided with a third outlet for the vaporized oil and gas to be discharged, and the top of the first shell is provided with a fourth outlet.

[0054] In some embodiments, the sludge treatment system further includes an air preheating unit, a hot side of the air preheating unit being connected to a hot side of the waste heat recovery unit and the drying unit, and a cold side of the air preheating unit being connected to an air source, the pyrolysis gasification unit and the molten combustion unit.

[0055] In some embodiments, the fractional distillation unit is further connected to the extractive separation unit.

[0056] In some embodiments, the molten combustion unit is further connected to a fuel gas source.

[0057] In some embodiments, the mixing unit is a reaction kettle with a stirrer or a container with a stirrer.

[0058] In some embodiments, the angle between the inclined plate and the horizontal plane is 25-35°.

[0059] The oil sludge treatment method of the present application can at least bring the following beneficial effects:

[0060] 1. After mixing the oil sludge with the extraction solvent, the extraction separation, pyrolysis gasification and melt combustion treatment are carried out in sequence, which can improve the oil sludge pyrolysis oil yield and realize the green and harmless treatment of pyrolysis residue. Specifically:

[0061] Mixing the oil sludge with the extraction solvent and extracting and separating them can achieve two oil phase extraction and separation of the oil sludge, and preliminarily achieve an oil sludge oil phase yield of 34-46%wt, which is much higher than the traditional oil sludge pyrolysis oil yield (25-38%wt).

[0062] The oil sludge residue after extraction and separation is subjected to pyrolysis and gasification reaction. The resulting gasified sludge composition does not contain unrecovered oil products and can be directly melted and harmlessly treated. The resulting slag can be green landfilled after cooling.

[0063] 2. The whole process of green disposal and energy integration of oily sludge is realized. Specifically: after the oily sludge is mixed with the extraction solvent, extraction separation, pyrolysis gasification and melt combustion treatment are carried out in sequence, and the extracted and separated oily sludge mixture is subjected to oil-gas separation and graded distillation, and the recovered extraction solvent can be reused in the mixing process of oily sludge and extraction solvent; the hot flue gas generated by the melt combustion is exchanged with water and air in sequence, which, on the one hand, realizes the cascade utilization of waste heat, and on the other hand, the obtained superheated steam can be used as reaction gas and part of the preheated air can participate in pyrolysis gasification, and part of the preheated air can be burned with the gasification gas obtained by oil and gas separation to provide the heat required for melting gasification slag, and the flue gas after heat exchange with water and air can be used as drying gas for drying oily sludge.

[0064] The oil sludge treatment system of the present application can be used for the oil sludge treatment method of the present application, and it at least has the beneficial effects of the oil sludge treatment method of the present application.

[0065] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings.

[0067] in:

[0068] Figure 1 The flowchart of an oil sludge treatment method (indirect contact heat exchange between gasified oil gas and oil sludge / extraction solvent mixture) shown in an exemplary embodiment of the present application.

[0069] Figure 2 for Figure 1 Flow chart of the corresponding sludge treatment system.

[0070] Figure 3 for Figure 2 Schematic diagram of the structure of the extraction and separation unit in the sludge treatment system.

[0071] Figure 4 This is a flow chart of an oil sludge treatment method (direct contact heat exchange between gasified oil gas and oil sludge / extraction solvent mixture) according to another exemplary embodiment of the present application.

[0072] Figure 5 for Figure 4 Flow chart of the corresponding sludge treatment system.

[0073] Figure 6 for Figure 5 Schematic diagram of the structure of the extraction and separation unit in the sludge treatment system.

[0074] Figure 7It is a schematic structural diagram of an exemplary device (melt pyrolysis device) in which a pyrolysis gasification unit and a melt combustion unit are integrated in the oil sludge treatment system of the present application.

[0075] Reference numerals:

[0076] 1-drying unit; 2-mixing unit; 3-extraction and separation unit; 301-first shell; 302-second shell; 303-first inlet; 304-first outlet; 305-inclined plate; 306-second inlet; 307-second outlet; 308-annular closed space; 309-third outlet; 310-fourth outlet; 4-pyrolysis and gasification unit; 5-molten combustion unit; 6-oil and gas separation unit; 7-graded distillation unit; 8-waste heat recovery unit; 9-air preheating unit; 200-slag pool; 201-combustion chamber; 202-feeding pipe; 203-storage hopper; 204-smoke channel; 205-air hole. DETAILED DESCRIPTION

[0077] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0078] In this application, the disclosure of numerical ranges includes all values ​​within the entire range and the disclosure of further subdivided ranges, including the endpoints and sub-ranges given in these ranges.

[0079] In this application, the raw materials, equipment, etc. involved, unless otherwise specified, are all raw materials and equipment that can be made through commercial channels or known methods; the methods involved, unless otherwise specified, are all conventional methods.

[0080] In this application, normal temperature refers to 20-30°C.

[0081] The following describes an oil sludge treatment method and an oil sludge treatment system according to an embodiment of the present application with reference to the accompanying drawings.

[0082] Figure 1 The present invention is a flowchart of an oil sludge treatment method according to an exemplary embodiment of the present invention.

[0083] like Figure 1 As shown, the sludge treatment method of the embodiment of the present application comprises the following steps:

[0084] S101, drying the oil sludge and mixing it with an extraction solvent to obtain a first mixture.

[0085] In some embodiments, the sludge consists of combustibles, water, inert ash, and the like.

[0086] As a non-limiting example, the oil sludge includes but is not limited to ground block sludge, scum sludge, pipeline sludge, tank bottom sludge, storage and transportation sludge, drying sludge, etc. Optionally, their physical properties are analyzed as shown in Table 1 and Table 2.

[0087] Table 1 Analysis of oil sludge properties - industrial analysis

[0088]

[0089] Table 2 Analysis of oil sludge physical properties - elemental analysis and calorific value

[0090]

[0091] In some embodiments, the temperature of the sludge is room temperature.

[0092] In some embodiments, the water content of the sludge is 45-60 wt %, including but not limited to 45%, 50%, 55% or 60%.

[0093] In some embodiments, the drying temperature is 200-250°C, including but not limited to 200°C, 210°C, 220°C, 230°C, 240°C or 250°C.

[0094] In some embodiments, the moisture content of the sludge after drying is 20-30 wt %, including but not limited to 20%, 22.5%, 25%, 27.5% or 30%, etc.

[0095] In some embodiments, the temperature of the sludge after drying is 40-60°C, including but not limited to 40°C, 45°C, 55°C, or 60°C.

[0096] In some embodiments, the methods of drying the sludge include but are not limited to oven drying, natural air drying, spray drying, heat exchange drying, etc.

[0097] As an optional example, the oil sludge is dried by heat exchange drying, and the drying gas includes but is not limited to hot flue gas, high-temperature steam, etc., such as hot flue gas with a temperature of 200-250° C. Preferably, the drying gas and the oil sludge are in direct contact for heat exchange.

[0098] In the embodiments of the present application, the oil sludge is dried and then mixed with an extraction solvent to complete the preliminary extraction of the oil phase in the oil sludge.

[0099] In some embodiments, the method of mixing the dried sludge with the extraction solvent includes stirring mixing or ultrasonic dispersion.

[0100] As an optional example, the method of mixing the dried sludge with the extraction solvent is stirring.

[0101] It should be noted that in the embodiments of the present application, the more uniformly the sludge is mixed with the extraction solvent after drying, the better the initial extraction effect of the oil phase in the sludge.

[0102] In some embodiments, in the first mixture, the mass ratio of the dried sludge to the extraction solvent is 1:1-1:2, including but not limited to 1:1, 1:1.25, 1:1.5, 1:1.75 or 1:2, etc.

[0103] In some embodiments, the extraction solvent includes but is not limited to at least one of light coal tar, benzene, toluene, and the like.

[0104] S102, extracting and separating the first mixture to obtain oil sludge and an oil-containing gas phase mixture.

[0105] In some embodiments, the temperature of the extraction separation is 200-350°C, including but not limited to 200°C, 250°C, 300°C or 350°C.

[0106] It should be noted that in the embodiments of the present application, the temperature for extraction and separation can be provided by heat exchange between the heat medium and the first mixture, or can be achieved by electric heating and other methods. When heat exchange is performed by a heat medium, the heat exchange method can be direct contact heat exchange between the heat medium and the first mixture or indirect contact heat exchange. Among them, direct contact heat exchange is conducive to direct contact between the heat medium and the first mixture, with high heat exchange efficiency and high extraction efficiency; indirect heat exchange, the heat exchange efficiency is slightly lower than direct contact heat exchange, but the oil extraction efficiency can be improved by increasing the amount of heat medium.

[0107] It should be noted that in the embodiments of the present application, when heat medium is used for heat exchange, the extraction temperature can be adjusted by the amount of heat medium and the amount of the first mixture so as to be basically maintained at 200-350°C.

[0108] As a non-limiting example, the heat medium includes but is not limited to gasified oil gas, high temperature inert gas (such as argon, nitrogen, etc.), blast furnace gas, etc., but preferably the gasified oil gas generated by the subsequent pyrolysis gasification process of the present application. At this time, the oil sludge treatment method also includes:

[0109] During the extraction and separation process, the vaporized oil and gas are subjected to indirect or direct heat exchange with the first mixture.

[0110] In some embodiments, the extraction and separation time is 2-4 min, including but not limited to 2 min, 2.5 min, 3 min, 3.5 min or 4 min.

[0111] In some embodiments, the composition of the oil sludge includes: combustibles and inert ash, etc.

[0112] In some embodiments, the temperature of the oil sludge residue is 200-300°C, including but not limited to 200°C, 220°C, 250°C, 280°C or 300°C.

[0113] In some embodiments, the oil-gas phase mixture includes a first oil-gas phase mixture and a second oil-gas phase mixture, the first oil-gas phase mixture includes tar and water, etc., and the second oil-gas phase mixture includes extraction solvent and light oil, etc.

[0114] S103, subjecting the oil sludge, superheated steam and the first oxidant to a pyrolysis and gasification reaction to obtain gasified oil gas and gasified slag.

[0115] In some embodiments, the mass ratio of oil sludge, superheated steam and the first oxidant is (0.8-1.0):(0.48-1.2):(0.1-0.6), including but not limited to 0.8:0.48:0.1, 0.8:0.48:0.6, 1.0:0.48:0.1, 1.0:1.2:0.6, 1.0:0.48:0.6 or 0.9:0.8:0.35, etc.

[0116] In some embodiments, the first oxidant includes preheated air. As a non-limiting example, the temperature of the preheated air is 150-200°C, including but not limited to 150°C, 165°C, 180°C or 200°C.

[0117] In some embodiments, the temperature of the superheated steam is 300-500°C, including but not limited to 300°C, 350°C, 400°C, 450°C or 500°C.

[0118] In some embodiments, the reaction temperature of the pyrolysis gasification is 800-850°C, including but not limited to 800°C, 810°C, 820°C, 830°C, 840°C or 850°C.

[0119] In some embodiments, the reaction time of pyrolysis and gasification is 3-10 min, including but not limited to 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min.

[0120] In some embodiments, the temperature of the gasified oil gas is 700-800°C, including but not limited to 700°C, 725°C, 750°C, 775°C or 800°C.

[0121] In some embodiments, the composition of gasified slag includes: combustibles with poor gasification reactivity and inert ash, etc.

[0122] In some embodiments, the temperature of the gasified slag is 760-800°C, including but not limited to 760°C, 770°C, 780°C, 790°C or 800°C.

[0123] S104, separating at least a portion of the oil-gas mixture into oil and gas to obtain gasified gas.

[0124] In some embodiments, Figure 1 As shown, when the gasified oil and gas are indirectly heat exchanged with the first mixture, at least a portion of the oil-containing gas phase mixture is subjected to oil and gas separation, including:

[0125] The first oil-gas phase mixture is subjected to oil-gas separation to obtain gasified gas and a first liquid phase; the first liquid phase includes tar.

[0126] In some embodiments, the oil sludge treatment method further comprises:

[0127] fractionally distilling the mixture of the first liquid phase and the second oil-containing gas phase to obtain recovered extraction solvent, light oil, water and heavy oil;

[0128] The recovered extraction solvent is reused in the process of mixing the sludge with the extraction solvent after drying in step S101.

[0129] In other embodiments, Figure 4 As shown, when the gasified oil and gas are directly heat exchanged with the first mixture, at least a portion of the oil-containing gas phase mixture is subjected to oil and gas separation, including:

[0130] The oil-gas mixture is subjected to oil-gas separation to obtain gasified gas and a second liquid phase; the second liquid phase is used to extract solvent, light oil and tar.

[0131] In some embodiments, the oil sludge treatment method further comprises:

[0132] The second liquid phase is fractionally distilled to obtain extraction solvent, light oil, water and heavy oil;

[0133] The recovered extraction solvent is reused in the process of mixing the sludge with the extraction solvent after drying in step S101.

[0134] It should be noted that in the embodiments of the present application, the recovered extraction solvent is reused in the process of mixing with the extraction solvent after the sludge is dried in step S101. Specifically, the recovered oil extraction solvent is used as the extraction solvent in step S101 to complete the preliminary extraction of the oil phase in the sludge.

[0135] In some embodiments, the composition of the gasification gas includes carbon monoxide, carbon dioxide, hydrogen, methane, etc.

[0136] S105, combusting the fuel gas and the second oxidant, and utilizing the heat generated by the combustion to melt the gasified slag to obtain molten slag and hot flue gas; the fuel gas includes the gasification gas obtained in step S104.

[0137] In some embodiments, the second oxidant includes preheated air. As a non-limiting example, the temperature of the preheated air is 150-200°C.

[0138] In some embodiments, when the amount of gasification gas obtained in step S104 is insufficient, fuel gas may be added as a supplement to the gasification gas, and the two may be used together as fuel gas.

[0139] In some embodiments, the composition of the slag includes: heavy metals, silicon dioxide, aluminum oxide, etc.

[0140] In some embodiments, the hot flue gas comprises carbon dioxide, water vapor, trace carbon monoxide, and the like.

[0141] In some embodiments, the temperature of the hot flue gas is 1200-1400°C, including but not limited to 1200°C, 1250°C, 1300°C, 1350°C or 1400°C.

[0142] In some embodiments, the oil sludge treatment method further includes: performing a first heat exchange between the hot flue gas and water to obtain superheated steam and the hot flue gas after a first cooling.

[0143] In some embodiments, the temperature of the water is ambient temperature.

[0144] In some embodiments, the temperature of the superheated steam is 300-450° C., which can be used in step S103 .

[0145] In some embodiments, the oil sludge treatment method further includes: exchanging heat between the hot flue gas after the first cooling and air to obtain preheated air and the hot flue gas after the second cooling.

[0146] In some embodiments, the temperature of the air is ambient temperature.

[0147] In some embodiments, the preheated air has a temperature of 150-200° C. and can be used as the first oxidant and / or the second oxidant.

[0148] In some embodiments, the oil sludge treatment method further includes: using the hot flue gas after the second temperature reduction as drying gas in the drying process in step S101.

[0149] In some embodiments, the temperature of the hot flue gas after the second cooling is 200-250°C, including but not limited to 200°C, 210°C, 220°C, 230°C, 240°C or 250°C.

[0150] In some embodiments, the melting temperature is 1300-1500°C, including but not limited to 1300°C, 1350°C, 1400°C, 1450°C or 1500°C.

[0151] In some embodiments, the melting time is 0.5-1.0 h, including but not limited to 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h or 1.0 h, etc.

[0152] The oil sludge treatment method of the embodiment of the present application can at least bring the following beneficial effects:

[0153] 1. After mixing the oil sludge with the extraction solvent, the oil sludge is sequentially subjected to extraction separation, pyrolysis gasification and melt combustion treatment, which can improve the quality of the oil sludge pyrolysis oil and achieve green and harmless treatment of the pyrolysis residue. Specifically:

[0154] Mixing the oil sludge with the extraction solvent and extracting and separating them can achieve two oil phase extraction and separation of the oil sludge, and preliminarily achieve an oil sludge oil phase yield of 34-46%wt, which is much higher than the traditional oil sludge pyrolysis oil yield (25-38%wt).

[0155] The oil sludge residue after extraction and separation is subjected to pyrolysis and gasification reaction. The resulting gasified sludge composition does not contain unrecovered oil products and can be directly melted and harmlessly treated. The resulting slag can be green landfilled after cooling.

[0156] 2. The whole process of green disposal and energy integration of oily sludge is realized. Specifically: after the oily sludge is mixed with the extraction solvent, extraction separation, pyrolysis gasification and melt combustion treatment are carried out in sequence, and the extracted and separated oily sludge mixture is subjected to oil-gas separation and graded distillation, and the recovered extraction solvent can be reused in the mixing process of oily sludge and extraction solvent; the hot flue gas generated by the melt combustion is exchanged with water and air in sequence, which, on the one hand, realizes the cascade utilization of waste heat, and on the other hand, the obtained superheated steam can be used as reaction gas and part of the preheated air can participate in pyrolysis gasification, and part of the preheated air can be burned with the gasification gas obtained by oil and gas separation to provide the heat required for melting gasification slag, and the flue gas after heat exchange with water and air can be used as drying gas for drying oily sludge.

[0157] It should be noted that the structure of the processing system of the sludge processing method of the embodiment of the present application is not limited, as long as the sludge processing method of the above embodiment of the present application can be implemented.

[0158] Figure 2 for Figure 1 Flow chart of the corresponding sludge treatment system. The sludge treatment system can be used to treat sludge in the sludge treatment method of the embodiment of the present application. Figure 2As shown, the oil sludge treatment system includes a drying unit 1, a mixing unit 2, an extraction and separation unit 3, a pyrolysis and gasification unit 4 and a molten combustion unit 5. Among them: the drying unit 1 is used to dry the oil sludge; the mixing unit 2 is connected to the drying unit 1 and the extraction solvent source to mix the dried oil sludge with the extraction solvent to obtain a first mixture; the extraction and separation unit 3 is connected to the mixing unit 2 to extract and separate the first mixture to obtain oil sludge residue and an oil-containing gas phase mixture; the pyrolysis and gasification unit 4 is connected to the extraction and separation unit 3 to pyrolyze and gasify the oil sludge residue to obtain gasified oil gas and gasified slag; the molten combustion unit 5 is connected to the pyrolysis and gasification unit 4, and the molten combustion unit 5 is used to subject the gasified slag to molten combustion treatment to obtain molten slag and hot flue gas.

[0159] In some embodiments, the drying unit 1 is a drum dryer, a belt dryer, a fluidized bed dryer, or the like.

[0160] In some embodiments, the mixing unit 2 is a reaction kettle with a stirrer or a container with a stirrer.

[0161] In some embodiments, Figure 3 and Figure 6 As shown, the extraction and separation unit 3 includes a first shell 301, a first inlet 303 for the first mixture to enter the first shell 301 is provided at the top of the first shell 301, a first outlet 304 for the sludge residue to be discharged is provided at the bottom of the first shell 301, and a plurality of inclined plates 305 are spaced apart on opposite sides of the first shell 301, and the angle between two adjacent inclined plates 305 is an acute angle.

[0162] In some embodiments, the angle between the inclined plate 305 and the horizontal plane is 25-35°, such as 25°, 30° or 35°.

[0163] In some embodiments, a plurality of inclined plates 305 spaced apart on opposite sides of the first shell 301 form a zigzag material discharge channel.

[0164] As an alternative example, Figure 3 and Figure 6 As shown, the two opposite sides in the first housing 301 are the first side 3011 and the second side 3012. For the inclined plate installed on the first side, one end thereof is fixedly connected to the first side in the first housing 301 (for example, by welding, bolting, etc.), and a gap is left between the other end and the second side; for the inclined plate installed on the second side, one end thereof is fixedly connected to the second side in the first housing 301 (for example, by welding, bolting, etc.), and a gap is left between the other end and the first side. As a non-limiting example, the gap is 1 / 5-1 / 4 of the gap between the first side and the second side, such as 1 / 5, 9 / 40 or 1 / 4, etc.

[0165] In some embodiments, Figure 6 As shown, a second inlet 306 for gasified oil gas to enter the first shell 301 is provided at the lower end of the first shell 301 , and a second outlet 307 is provided at the upper end of the first shell 301 .

[0166] In some embodiments, Figure 3 As shown, the extraction and separation unit 3 also includes a second shell 302, which is sleeved on the outside of the first shell 301, and the inner wall of the second shell 302 and the outer wall of the first shell 301 form an annular closed space 308; the lower end of the second shell 302 is provided with a second inlet 306 for gasified oil and gas to enter the first shell 301, the upper end of the second shell 302 is provided with a third outlet 309 for gasified oil and gas to be discharged, and the top of the first shell 301 is provided with a fourth outlet 310.

[0167] In some embodiments, the bottom of the first shell 301 is funnel-shaped (ie, a frustum or prism shape that is larger at the top and smaller at the bottom).

[0168] In some embodiments, the shape of the first shell 301 includes but is not limited to a cylinder, a prism, a cuboid, etc.

[0169] In some embodiments, the shape of the second shell 302 includes but is not limited to a cylinder, a prism, a cuboid, etc.

[0170] As an optional example, the first shell 301 and the second shell 302 are both cylindrical in shape and are coaxially arranged.

[0171] In some embodiments, the pyrolysis gasification unit 4 and the melt combustion unit 5 are separately provided or integrally formed.

[0172] In some embodiments, the pyrolysis gasification unit 4 is a rotary kiln, a pyrolysis furnace, etc.

[0173] In some embodiments, the melt combustion unit is a melting furnace, a cyclone furnace, etc.

[0174] In other embodiments, the pyrolysis gasification unit 4 and the melt combustion unit 5 are integrally formed.

[0175] As an alternative example, Figure 7 As shown, the device in which the pyrolysis gasification unit 4 and the molten combustion unit 5 are integrally formed is a molten pyrolysis device, which includes a slag pool 200 and a combustion chamber 201. At least one feed pipe 202 is arranged in the slag pool 200, and the upper end of the feed pipe 202 extends out of the top of the slag pool 200 and is connected to a storage hopper 203 storing oil sludge residue. At least one flue gas channel 204 is arranged below the feed pipe 202, and the flue gas channel is located in the slag pool 200. The flue gas channel 204 is connected to the combustion chamber 201, and the combustion chamber 201 is located outside the slag pool 200.

[0176] In some embodiments, the distance between the flue gas channel 204 and the bottom of the slag pool 200 is 3-6 cm.

[0177] In some embodiments, at least one air hole 205 is disposed on the smoke channel 204 .

[0178] In some embodiments, the lower end of the feed pipe 202 is inserted below the liquid level in the slag pool 200 .

[0179] As a non-limiting example, the lower end of the feed pipe 202 is inserted into the slag pool 200 to a depth of 0.2-0.3 m below the liquid surface.

[0180] In some embodiments, the combustion chamber 201 has a second oxidant inlet for entering a second oxidant, a hot flue gas outlet is provided at the upper end of the slag pool 200, and a slag outlet is provided at the bottom of the slag pool 200.

[0181] In some embodiments, the combustion chamber can be a burner closed square furnace, a closed tube furnace, etc.

[0182] It should be noted that in Figure 7 In the melting pyrolysis device shown, the gasified oil gas produced by pyrolysis is discharged from the storage hopper from bottom to top. In addition, the slag pool is a closed hollow space, and the lower end of the feed pipe is open, so that the pyrolysis gasified slag can enter the slag pool for melting.

[0183] In some embodiments, Figure 2 and Figure 5 As shown, the oil sludge treatment system also includes an oil-gas separation unit 6 , which is connected to the extraction separation unit 3 , the melting combustion unit 5 and the fractional distillation unit 7 , and the fractional distillation unit 7 is connected to the mixing unit 2 .

[0184] In some embodiments, the oil-gas separation unit 6 is a water-cooled spray tank, a condensation tower, etc.

[0185] In some embodiments, the fractional distillation unit 7 is a distillation column or the like.

[0186] In some embodiments, Figure 2 and Figure 5 The oil sludge treatment system further includes a waste heat recovery unit 8 , and a cold side of the waste heat recovery unit 8 is connected to a water source and the pyrolysis gasification unit 4 .

[0187] In some embodiments, the waste heat recovery unit 8 is a waste heat boiler or the like.

[0188] In some embodiments, the sludge treatment system also includes an air preheating unit 9, the hot side of the air preheating unit 9 is connected to the hot side of the waste heat recovery unit 8 and the drying unit 1, and the cold side of the air preheating unit 9 is connected to the air source, the pyrolysis gasification unit 4 and the molten combustion unit 5.

[0189] In some embodiments, the air preheating unit 9 is an air preheater, etc. When an air preheater is used, it can be a plate heat exchanger, a shell and tube heat exchanger, etc.

[0190] In some embodiments, Figure 2 As shown, the fractional distillation unit 7 is also connected to the extractive separation unit 3 .

[0191] In some embodiments, the melt combustion unit 5 is also connected to a fuel gas source.

[0192] The sludge treatment system of the embodiment of the present application can be used to implement the sludge treatment method of the embodiment of the present application. Optionally, the specific process is:

[0193] The hot flue gas from the air preheating unit 9 (i.e., the hot flue gas after the second cooling) directly contacts and exchanges heat with the oil sludge through the drying unit 1 to reduce the moisture content of the oil sludge to 20-30%wt, and then is discharged after environmental protection treatment and meets the standards. The dried oil sludge is then fully stirred with the extraction solvent in the mixing unit to form an oil sludge / extraction solvent mixture (i.e., the first mixture) to complete the preliminary extraction of the oil phase in the oil sludge; the oil sludge / extraction solvent mixture then enters the extraction and separation unit 3 to directly or indirectly contact and heat-exchange with the high-temperature gasified oil gas to separate light oil, heavy oil, water and oil sludge residue; the oil sludge residue after extraction and separation enters the pyrolysis gasification unit 3. The gasification unit 4 performs pyrolysis and gasification reaction with superheated steam and preheated air to generate gasified oil gas and gasified slag. The gasified oil gas is separated into gasified gas (when the amount of gasified gas is insufficient, fuel gas is added as a supplement) by the extraction and separation unit 3 and the oil-gas separation unit 6. The gasified gas is burned with the preheated air in the melting combustion unit. The hot flue gas generated by the combustion provides heat for the melting process of the gasified slag. The glassy slag generated by the melting combustion unit is green landfilled after cooling. The hot flue gas generated enters the waste heat recovery unit 8 and the air preheating unit 9 to exchange heat with normal temperature water and normal temperature air respectively to generate superheated steam and preheated air. The process flow is as follows: Figure 1 shown.

[0194] The hot flue gas inlet temperature of the drying unit 1 is controlled at 200-250°C, the flue gas outlet temperature is 110-130°C, and the moisture content is 45-60wt%. The temperature of the sludge at room temperature is kept at 40-60°C after drying, and the moisture content is reduced to 20-30wt%. In the mixing unit 2, the dried sludge and the extraction solvent are stirred and mixed in a glass fiber reinforced plastic container with a stirrer to achieve the initial oil phase separation of the sludge. The mass ratio of the dried sludge and the extraction solvent is controlled at 1:1-1:2. The extraction solvent used can be at least one of light coal tar, benzene, toluene and other organic solvents.

[0195] The extraction separation unit 3 mainly realizes direct and indirect heat exchange between the oil sludge / extraction solvent mixture and the 700-800℃ gasified oil gas from the pyrolysis gasification unit to further separate the oil phase in the oil sludge. Figure 3 and Figure 6 As shown. The sludge / extraction solvent mixture enters the extraction and separation unit 3 through the upper sludge + extraction solvent inlet (i.e., the first inlet 303). The extraction and separation unit 3 is provided with multiple groups (2 groups or more) of inclined plates with an angle of 25-35° with the horizontal plane. The sludge / extraction solvent mixture exchanges heat with the 700-800°C vaporized oil gas from top to bottom, and the 200-300°C sludge residue is finally discharged from the sludge residue outlet (i.e., the first outlet 304) of the extraction and separation unit 3. The residence time of the sludge / extraction solvent mixture in the extraction and separation unit 3 is controlled to be 2-4 minutes. Figure 1-3 As shown, when the indirect contact heat exchange extraction separation method is adopted, the 700-800°C vaporized oil gas enters through the second inlet 306 on the second shell 302 of the extraction separation unit, and after heat exchange with the oil sludge / extraction solvent mixture in the first shell 301, the temperature drops to 300-400°C and enters the oil-gas separation unit 6 through the third outlet 309 on the second shell 302 to separate the room temperature tar and the room temperature vaporized gas. The oil sludge / extraction solvent mixture in the first shell 301 of the extraction separation unit 3 is heat exchanged with the gasified oil gas in the second shell 302, and the extraction solvent with a temperature of 200-300°C and the separated light oil are discharged from the fourth outlet 310 to enter the graded distillation unit 7, and are distilled together with the room temperature tar to separate the light oil, heavy oil, water and oil sludge residue, and the extraction solvent is recycled to the mixing unit 2; as shown in FIG. Figure 4-6 As shown, when a direct contact heat exchange extraction separation method is adopted, 700-800°C vaporized oil and gas enters through the inlet (i.e., the first inlet 303) of the extraction separation unit 3, and after direct heat exchange with the oil sludge / extraction solvent mixture, the temperature drops to 300-350°C, and then enters the oil and gas separation unit together with the extraction solvent from the second outlet 307 to separate the room temperature vaporized gas, and the room temperature oil phase (including vaporized oil and gas tar) and the extraction solvent enter the fractional distillation unit 7 to separate the light oil, heavy oil, water and oil sludge residue, and the extraction solvent is recycled to the mixing unit 2.

[0196] The pyrolysis and gasification reaction temperature in the pyrolysis and gasification unit 3 is controlled at 800-850°C. The 200-300°C oil sludge residue undergoes pyrolysis and gasification reaction with 300-450°C superheated steam and 150-200°C preheated air in the pyrolysis and gasification unit to produce 700-800°C gasified oil gas to provide heat for heat exchange in the extraction and separation unit 3. The 760-820°C gasified slag produced by the pyrolysis and gasification reaction enters the melting combustion unit 5 for melting and harmless treatment.

[0197] The melting temperature in the melting combustion unit 5 is controlled at 1300-1500°C to ensure that the gasified slag is melted into a glassy state. In the melting combustion unit 5, 150-200°C preheated air and normal temperature gasification gas (when the amount of gasification gas is insufficient, fuel gas is added as a supplement) are burned in the melting combustion unit 5, and the hot flue gas generated by the combustion provides heat for the melting process of the gasified slag. The glassy slag generated by the melting combustion unit 5 is green landfilled after cooling treatment. The hot flue gas of 1200-1400°C is successively entered into the waste heat recovery unit 8 and the air preheating unit 9 for heat exchange with normal temperature water and normal temperature air to generate 300-450°C superheated steam and 150-200°C preheated air. The flue gas of 200-250°C (that is, the hot flue gas after the second cooling) flowing out of the air preheating unit 9 further enters the drying unit 1 for sludge drying.

[0198] The air preheating unit 9 mainly utilizes the hot flue gas of 450-600°C after heat exchange in the waste heat recovery unit 8 (that is, the hot flue gas after the first cooling) to exchange heat with air at normal temperature. The preheated air is divided into two branches, one of which enters the pyrolysis gasification unit 4 as the first oxidant for pyrolysis and gasification of oil sludge, and the other enters the melting combustion unit 5 as the second oxidant and the gasification gas (when the amount of gasification gas is insufficient, fuel gas is added as a supplement) to carry out melting treatment of the gasified slag.

[0199] The oil sludge treatment system of the embodiment of the present application can be used for the oil sludge treatment method of the embodiment of the present application, so it at least has the beneficial effects of the oil sludge treatment method of the embodiment of the present application.

[0200] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0201] Application Case 1

[0202] Pipeline sludge (physical property analysis is shown in Tables 1 and 2 above) is used as a raw material, and the feed rate is controlled at 5 to 6 tons per hour. The flue gas at 220°C from the outlet of an air preheating unit (e.g., an air preheater) is directly contacted with the sludge through a drying unit (e.g., a drum dryer) for heat exchange, and the flue gas outlet temperature is 120°C and the moisture content is 50wt%. The sludge at room temperature is kept at 50°C after drying, and the moisture content is reduced to 25wt%. The dried sludge and toluene are mixed to form a sludge / toluene mixture, wherein the mixing mass ratio of the dried sludge and toluene is controlled at 1:1.2; the sludge / toluene mixture is mixed with 760°C gasified oil gas in an extraction separation unit (e.g., a Figure 6The extraction and separation unit is provided with 12 groups of inclined plates which are at an angle of 32° to the horizontal. The 240°C oil sludge residue produced by the extraction and separation is discharged from the oil sludge residue outlet and enters the pyrolysis gasification unit (e.g., a rotary kiln). The residence time of the oil sludge / toluene mixture in the extraction and separation unit is controlled at 2.5 min. The pyrolysis oil gas, toluene, light oil and tar are subsequently separated by an oil-gas separation unit (e.g., a condensation tower) and a graded distillation unit (e.g., a distillation tower). The toluene is continuously recycled to the mixing unit (e.g., a reactor with an agitator). The light oil, tar and gasified oil gas are separated by a gas separation unit (e.g., a condensation tower) and a graded distillation unit (e.g., a distillation tower). The tar in the oil sludge is used as the oil product produced by the treatment of oily sludge, and the oil sludge residue enters the pyrolysis gasification unit for pyrolysis gasification reaction. The mass ratio of oil sludge residue, superheated steam and preheated air is 0.8:0.6:0.2. The reaction temperature is controlled at 820℃. The 760℃ gasified oil gas produced provides heat exchange for the extraction and separation unit. The 760℃ gasified slag produced by the pyrolysis gasification reaction enters the melting combustion unit (for example, melting furnace) for melting harmless treatment; the 180℃ preheated air and room temperature gasification gas in the melting combustion unit (the amount of gasification gas is insufficient, and 120-150Nm of fuel gas is added per hour) 3 As a supplement) the molten combustion unit is burned, and the 1350℃ hot flue gas generated by the combustion provides heat for the gasification slag melting process. The melting combustion temperature is 1350℃, and the melting combustion time is 0.5h. The glassy slag produced by the melting combustion unit is green landfilled after cooling. The 1350℃ hot flue gas generated enters the waste heat recovery unit (for example, waste heat boiler) and the air preheating unit to exchange heat with normal temperature water and normal temperature air respectively to generate 350℃ superheated steam and 180℃ preheated air. The 220℃ flue gas after heat exchange in the above units further enters the drying unit for sludge drying. By controlling the process operation parameters of each of the above units, the oil phase yield of the pipeline sludge is basically maintained at 40-42%wt.

[0203] Application Case 2

[0204] Dried sludge (physical property analysis is shown in Tables 1 and 2 above) is used as a raw material, and the feed rate is controlled at 2 to 3 tons per hour. The flue gas at 200°C from the outlet of an air preheating unit (e.g., an air preheater) is directly in contact with the sludge through a drying unit (e.g., a drum dryer) for heat exchange, and the flue gas outlet temperature is 116°C and the moisture content is 48wt%. The temperature of the sludge at room temperature is maintained at 40 to 60°C after drying, and the moisture content is reduced to 24wt%. The dried sludge and toluene are mixed to form a sludge / toluene mixture, wherein the mixing mass ratio of the dried sludge and toluene is controlled at 1:1.6; the sludge / toluene mixture is mixed with 770°C gasified oil gas in an extraction separation unit (e.g., Figure 6The extraction and separation unit is provided with 8 groups of inclined plates which are at an angle of 28° to the horizontal. The 240°C oil sludge residue produced by the extraction and separation is discharged from the oil sludge residue outlet and enters the pyrolysis gasification unit (e.g., a rotary kiln). The residence time of the oil sludge / toluene mixture in the extraction and separation unit is controlled to be 3 minutes; the pyrolysis oil gas, toluene, light oil and tar are subsequently separated by an oil-gas separation unit (e.g., a condensation tower) and a graded distillation unit (e.g., a distillation tower), and the toluene is continuously recycled to the mixing unit, and the light oil, tar and tar in the gasified oil gas are used as The oil products produced by the oil sludge treatment and the oil sludge residue enter the pyrolysis gasification unit for pyrolysis gasification reaction. The mass ratio of oil sludge residue, superheated steam and preheated air is 1.0:1.0:0.4. The reaction temperature is controlled at 840℃. The 770℃ gasified oil gas produced provides heat exchange for the extraction and separation unit. The 770℃ gasified slag produced by the pyrolysis gasification reaction enters the melting combustion unit (for example, melting furnace) for melting harmless treatment; the 160℃ preheated air and room temperature gasification gas (the amount of gasification gas is insufficient, and 50-60Nm of fuel gas is added per hour) in the melting combustion unit. 3 As a supplement) the smelting combustion unit is used for combustion, and the 1400℃ hot flue gas generated by the combustion provides heat for the gasification slag melting process. The temperature of the smelting combustion is 1400℃, and the melting time is 0.8h. The glassy slag generated by the smelting combustion unit is green landfilled after cooling. The 1400℃ hot flue gas generated enters the waste heat recovery unit (for example, waste heat boiler) and the air preheating unit to exchange heat with normal temperature water and normal temperature air respectively to generate 450℃ superheated steam and 160℃ preheated air. The 200℃ hot flue gas after heat exchange in the above units further enters the drying unit for sludge drying. By controlling the process operation parameters of each of the above units, the oil phase yield of the dried sludge is basically maintained at 36-39%wt.

[0205] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0206] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0207] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for treating oily sludge, characterized in that: include: drying the oil sludge and mixing it with an extraction solvent to obtain a first mixture; Extracting and separating the first mixture to obtain oil sludge and an oil-containing gas phase mixture; The oil sludge, superheated steam and a first oxidant are subjected to pyrolysis and gasification reaction to obtain gasified oil gas and gasified slag; separating oil and gas from at least a portion of the oil-gas phase mixture to obtain gasified gas; During the extraction and separation process, the vaporized oil and gas are subjected to indirect or direct heat exchange with the first mixture; When the gasified oil and gas are indirectly heat exchanged with the first mixture, the step of separating at least a portion of the oil-containing gas phase mixture into oil and gas comprises: The oil-containing gas phase mixture includes a first oil-containing gas phase mixture and a second oil-containing gas phase mixture; the first oil-containing gas phase mixture includes tar and gasification gas, and the second oil-containing gas phase mixture includes light oil and the extraction solvent; The first oil-gas phase mixture is subjected to the oil-gas separation to obtain a first liquid phase and the gasified gas; the first liquid phase includes tar; When the gasified oil and gas are directly heat exchanged with the first mixture, the oil and gas separation of at least a portion of the oil-containing gas phase mixture comprises: The oil-gas phase mixture is subjected to the oil-gas separation to obtain a second liquid phase and the gasified gas; the second liquid phase includes light oil, tar and the extraction solvent; Combusting the fuel gas and the second oxidant, and using the heat generated by the combustion to melt the gasified slag to obtain molten slag and hot flue gas; the fuel gas includes the gasified gas; The pyrolysis and gasification reaction is carried out in a pyrolysis and gasification unit, the combustion and the melting are carried out in a melting combustion unit, the pyrolysis and gasification unit and the melting combustion unit are integrally formed, and include a slag pool and a combustion chamber, at least one feeder pipe is arranged in the slag pool, the upper end of the feeder pipe extends out from the top of the slag pool and is connected to a storage hopper storing the sludge residue, the lower end of the feeder pipe is inserted below the liquid level in the slag pool, at least one flue gas channel is arranged below the feeder pipe, the flue gas channel is located in the slag pool, the flue gas channel is connected to the combustion chamber, and the combustion chamber is located outside the slag pool.

2. The oil sludge treatment method according to claim 1, characterized in that: The oil sludge treatment method further comprises: fractionally distilling the mixture of the first liquid phase and the second oil-containing gas phase to obtain recovered extraction solvent, light oil, water and heavy oil; Reusing the recovered extraction solvent in the mixing process; Alternatively, the second liquid phase is subjected to fractional distillation to obtain recovered extraction solvent, light oil, water and heavy oil; The recovered extraction solvent is reused in the mixing process.

3. The oil sludge treatment method according to claim 1, characterized in that: The first oxidant and the second oxidant both include preheated air.

4. The oil sludge treatment method according to claim 3, characterized in that: The oil sludge treatment method further comprises: Performing a first heat exchange between the hot flue gas and water to obtain the superheated steam and the hot flue gas after a first cooling; Exchanging heat between the first cooled hot flue gas and air to obtain the preheated air and the second cooled hot flue gas; The second cooled hot flue gas is used as the drying gas for drying.

5. The oil sludge treatment method according to claim 1, characterized in that: The drying temperature is 200-250°C; and / or, in the first mixture, the mass ratio of the dried sludge to the extraction solvent is 1:(1-2); and / or, the extraction solvent comprises at least one of light coal tar, benzene and toluene; and / or, the temperature of the gasified oil gas is 700-800°C; And / or, the extraction and separation time is 2-4 min; And / or, the mass ratio of the oil sludge, superheated steam and the first oxidant is (0.8-1.0): (0.48-1.2): (0.1-0.6); And / or, the reaction temperature of the pyrolysis and gasification reaction is 800-850°C, and the reaction time of the pyrolysis and gasification reaction is 3-10min; And / or, the melting temperature is 1300-1500° C., and the melting time is 0.5-1.0 h; And / or, the method of mixing the dried sludge with the extraction solvent includes stirring mixing or ultrasonic dispersion.

6. An oil sludge treatment system used in the oil sludge treatment method according to any one of claims 1 to 5, characterized in that: include: A drying unit, used for drying the oil sludge; a mixing unit connected to the drying unit and an extraction solvent source to mix the dried sludge with the extraction solvent to obtain a first mixture; An extraction and separation unit, the extraction and separation unit is connected to the mixing unit to extract and separate the first mixture to obtain oil sludge and oil-containing gas phase mixture; A pyrolysis and gasification unit, the pyrolysis and gasification unit is connected to the extraction and separation unit and is used to pyrolyze and gasify the oil sludge to obtain gasified oil gas and gasified slag; A melting combustion unit is connected to the pyrolysis gasification unit, and is used to subject the gasified slag to a melting combustion process to obtain molten slag and hot flue gas.

7. The oil sludge treatment system according to claim 6, characterized in that: The extraction separation unit comprises a first shell, the top of the first shell is provided with a first inlet for the first mixture to enter the first shell, the bottom of the first shell is provided with a first outlet for the oil sludge to be discharged, and a plurality of inclined plates are arranged at intervals on two opposite sides of the first shell, and the angle between two upper and lower adjacent inclined plates is an acute angle; The oil sludge treatment system further comprises an oil-gas separation unit, the oil-gas separation unit is connected to the fractional distillation unit, the extraction separation unit and the melting combustion unit, and the fractional distillation unit is connected to the mixing unit; And / or, the oil sludge treatment system further comprises a waste heat recovery unit, and a cold side of the waste heat recovery unit is connected to a water source and a pyrolysis gasification unit.

8. The oil sludge treatment system according to claim 7, characterized in that: A second inlet for the vaporized oil gas to enter the first shell is provided at the lower end of the first shell, and a second outlet is provided at the upper end of the first shell; or, The extraction and separation unit further comprises a second shell, which is sleeved on the outside of the first shell, and the inner wall of the second shell and the outer wall of the first shell form an annular closed space; a second inlet for the gasified oil gas to enter the annular closed space is provided at the lower end of the second shell, a third outlet for the gasified oil gas to be discharged is provided at the upper end of the second shell, and a fourth outlet is provided at the top of the first shell; And / or, the oil sludge treatment system further comprises an air preheating unit, the hot side of the air preheating unit is connected to the hot side of the waste heat recovery unit and the drying unit, and the cold side of the air preheating unit is connected to an air source, the pyrolysis gasification unit and the melt combustion unit; And / or, the fractional distillation unit is also connected to the extraction separation unit; And / or, the molten combustion unit is also connected to a fuel gas source; And / or, the mixing unit is a reaction kettle with a stirrer or a container with a stirrer; And / or, the angle between the inclined plate and the horizontal plane is 25-35°.

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