Pyrolysis process and device for realizing resource classification and utilization of oil-containing sludge

Abstract

The application is a pyrolysis process and device for realizing classified utilization of oily sludge resources. The device for realizing the pyrolysis process of classified utilization of oily sludge resources comprises a feeding device, a front-end connecting cover, a rotary pyrolysis device, a tail-end connecting cover, a slag discharge port, a first air extraction pipe, a second air extraction pipe, a third air extraction pipe, a transmission device and a control system. The main body of the rotary pyrolysis device is a horizontal double-layer cylinder, comprising a concentrically arranged inner cylinder and an outer cylinder. In the process, water vapor, light component pyrolysis products and heavy component pyrolysis products generated by oily sludge in different temperature ranges are discharged from the rotary pyrolysis device through corresponding air extraction pipes. The application simplifies the process flow and improves the operation reliability of the equipment, can realize classified collection of pyrolysis products, and is helpful for classified and directional catalytic utilization of subsequent pyrolysis products.

Description

Technical Field

[0001] This invention belongs to the field of resource utilization of oily sludge, and particularly relates to a pyrolysis process and apparatus for realizing the classified utilization of oily sludge resources. Background Technology

[0002] Oily sludge is a solid waste generated in the petroleum industry during crude oil extraction, refining, transportation, and storage. my country's annual production of oily sludge is estimated at 5 million tons. Oily sludge has a complex composition and is characterized by its reluctance to degrade, toxicity, and harmfulness, falling under category HW08 in the National Hazardous Waste List. Oily sludge is a highly emulsified mixture of water, oil, and sludge, with water primarily existing as emulsified water. The four components of the oil phase in oily sludge are a fundamental parameter characterizing its properties: saturated hydrocarbons, aromatic hydrocarbons, gums, and asphaltenes. Generally, saturated hydrocarbons and aromatic hydrocarbons are considered light components, while gums and asphaltenes are considered heavy components. The presence of gums and asphaltenes promotes the emulsification stability of water, oil, and sludge in oily sludge, increasing its viscosity and thus making it more difficult to treat.

[0003] Currently, the treatment methods for oily sludge are mainly divided into two categories: harmless treatment and resource utilization. Harmless treatment technologies include incineration, stabilization / solidification, oxidation / novel oxidation, secure landfill, land cultivation, and composting. Resource utilization technologies include mechanical separation, solvent extraction, pyrolysis, and some newer methods such as microwave radiation, ultrasonic radiation, and freeze-thaw cycles. Pyrolysis can be applied to treat various types of oily sludge, especially high-viscosity, high-sludge-content oily sludge, and is currently the most industrially valuable resource utilization technology. The diverse types of oily sludge result in complex pyrolysis products, making it difficult to recover high-quality oil or gaseous products. How to efficiently and cleanly utilize oily sludge resources to produce clean oils, syngas, and chemicals is a major issue in my country's energy sector.

[0004] According to the thermal comprehensive analysis curve, the pyrolysis process of oily sludge is generally divided into three stages. The first stage is at room temperature -120℃, and the main occurrence is the evaporation of emulsified water. The second stage is at a temperature between 120℃ and 400℃, which corresponds to the volatilization and cracking of light components (C5-C20). The third stage is at a temperature between 400℃ and 550℃, which corresponds to the cracking of heavy components (C21-C30), and condensation reactions also begin to occur.

[0005] Generally, the oil products recovered from the pyrolysis of oily sludge contain both saturated hydrocarbons and aromatic hydrocarbons, and the content of heavy components remains relatively high, affecting their direct use as fuel oil. From a fuel perspective, for the recovered oil products to be used as fuel oil, the higher the content of straight-chain hydrocarbons and the lower the content of aromatic hydrocarbons, the higher the quality of the oil products. From an industrial perspective, the technology of preparing high-content aromatic hydrocarbon products from oily sludge is of great value; aromatic hydrocarbons have wide applications in the production of high-value-added chemical products and polymer preparation; however, currently, aromatic hydrocarbons are mainly extracted and prepared from fossil fuels, resulting in significant fossil fuel consumption. In addition, obtaining high-quality gaseous products from oily sludge is also a way to utilize its resources, and improving the tar conversion rate while producing gas is an urgent problem to be solved.

[0006] Adding catalysts during the pyrolysis of oily sludge can achieve targeted pyrolysis, thereby obtaining high-value pyrolysis products. For example, catalysts such as CaO, NiO, and dolomite facilitate the generation of light oils rich in chain hydrocarbons; metal-supported ZSM-5 and HZSM-5 molecular sieves can improve the selectivity and yield of aromatic hydrocarbons during pyrolysis; and coke catalysts can help obtain hydrogen-rich gases. The selection of catalysts for the pyrolysis of oily sludge needs to be determined based on the characteristics of the oily sludge and the target products.

[0007] Patent (CN 202121317859.7) discloses a rotary oily sludge pyrolysis device, including a feeding device, a kiln body, a heating device, a connecting hood, a discharging device, and a transmission device. The kiln body consists of three sections connected by connecting hoods. By setting up three independently heated, interconnected rotary kilns, each section extracts a pyrolysis product from its tail end, achieving continuous operation of oily sludge drying, low-temperature pyrolysis, and high-temperature pyrolysis, and significantly improving the quality of the recovered oil. However, the connection between the kiln sections via connecting hoods and the presence of transmission and heating devices in each section significantly increases system complexity and operational reliability.

[0008] Based on existing problems, this paper proposes a method to achieve pyrolysis of oily sludge in a single pyrolysis unit and discharge the pyrolysis products at an appropriate location, simplifying the process and improving equipment reliability. Considering the targeted catalytic utilization of different pyrolysis products from oily sludge, a solution for the classified utilization of oily sludge resources is also proposed. Summary of the Invention

[0009] The purpose of this invention is to address the limitations of current technologies by proposing a pyrolysis process and apparatus for the classified utilization of oily sludge resources. The main body of the apparatus is a single-stage rotary kiln, within which three exhaust pipes are installed. Water vapor, light component pyrolysis products, and heavy component pyrolysis products generated at different temperature ranges are discharged from the rotary pyrolysis equipment through their respective exhaust pipes. This invention simplifies the process flow and improves the reliability of equipment operation, enabling the classified collection of pyrolysis products, which facilitates the subsequent classified and targeted catalytic utilization of these products.

[0010] The technical solution of this invention is:

[0011] A pyrolysis process for the classified utilization of oily sludge resources includes the following steps:

[0012] Oily sludge at room temperature in the storage silo is fed into the inner cylinder of the rotary pyrolysis equipment via a rotary discharge valve and screw conveyor; the oily sludge moves from left to right through the inner cylinder; at the same time, hot flue gas at 750-850℃, the heating medium, enters the outer cylinder of the rotary pyrolysis equipment through the hot flue gas inlet, and moves from right to left, indirectly and countercurrently exchanging heat with the oily sludge through the inner cylinder wall; finally, flue gas at 120-150℃ is discharged from the outer cylinder through the flue gas outlet.

[0013] The first exhaust pipe removes the generated water vapor, the second exhaust pipe removes the light component pyrolysis products generated in the temperature range of 120-400℃, and the third exhaust pipe removes the heavy component pyrolysis products generated in the temperature range of 400-550℃, which are then discharged from the inner cylinder.

[0014] The oily sludge entering the feeding equipment has the following characteristics: water content 0-10%; oil content 50-90%; and slag content 5-40%.

[0015] All ratios mentioned are mass percentages;

[0016] The heating medium is industrial flue gas, preferably hot flue gas produced by a hot blast furnace.

[0017] The temperature ranges for the generation of water vapor, pyrolysis products of light components, and pyrolysis products of heavy components are room temperature -120℃, 120-400℃, and 400-550℃, respectively.

[0018] The air inlet temperature of the outer cylinder from right to left is 750-850℃, and the air outlet temperature is 120-150℃; the temperature of the oily sludge in the inner cylinder from left to right is in the range of room temperature to 600℃.

[0019] The feed rate is 0.2–1.5 t / h; the air intake is 1000–10000 Nm³. 3 / h; the rotational speed of the inner cylinder is 0.5-2 rpm;

[0020] The light component pyrolysis products can be catalytically pyrolyzed at 450-550℃ under the action of different catalysts to obtain light oil rich in chain hydrocarbons or oil products rich in aromatic hydrocarbons.

[0021] The pyrolysis products of the heavy components undergo a thermocatalytic water vapor reforming reaction at 800-1000℃ to generate small molecule gases such as H2, CO, and CH4.

[0022] The pyrolysis residue has an oil content of less than 0.3% and its main components are oxides such as SiO2, Fe2O3, Al2O3, and CaO, which can be used as building material raw materials.

[0023] The apparatus for realizing the classified utilization of oily sludge resources through pyrolysis includes a feeding device, a front-end connecting cover, a rotary pyrolysis device, a tail-end connecting cover, a slag discharge port, a first exhaust pipe, a second exhaust pipe, a third exhaust pipe, a transmission device, and a control system.

[0024] The rotary pyrolysis equipment has a front connecting cover at the front end and a tail connecting cover at the rear end, which are dynamically connected to both ends of the inner cylinder. The feeding equipment consists of a storage bin, a rotary discharge valve, and a screw conveyor, located in front of the rotary pyrolysis equipment, and transports oily sludge into the equipment. The discharge port is located at the bottom of the tail connecting cover and is connected to the residue cooler. The first exhaust pipe is connected to the front connecting cover, and the second and third exhaust pipes are connected to the tail connecting cover. The first exhaust pipe is located in the steam generation area. The second and third exhaust pipes are coaxially arranged, with the second exhaust pipe located in the light component pyrolysis product generation area and the third exhaust pipe located in the heavy component pyrolysis product generation area. All exhaust pipes are connected to an induced draft fan.

[0025] The rotary pyrolysis equipment is a horizontal double-layered cylinder consisting of an inner cylinder and an outer cylinder arranged concentrically. The length of the outer cylinder is 70-85% of the length of the inner cylinder. A large gear installed on the inner cylinder meshes with a small gear, which in turn connects to a reducer and a motor, thereby enabling the rotation of the inner cylinder. The outer cylinder is fixed and does not rotate. The outer cylinder is equipped with a hot flue gas inlet and a flue gas outlet. Several temperature sensors are also installed inside the outer cylinder. The temperature sensors are electrically connected to the control device.

[0026] The first exhaust pipe is located in the water vapor generation area, corresponding to 10-40% of the inner cylinder length; the second exhaust pipe is located in the light component pyrolysis product generation area, corresponding to 45-70% of the inner cylinder length; the third exhaust pipe is located in the heavy component pyrolysis product generation area, corresponding to 75-92% of the inner cylinder length.

[0027] The diameter of the inner cylinder ranges from 1.4 to 3.0 m, and the length ranges from 6.0 to 18.0 m.

[0028] The distance between the center of the first exhaust pipe and the highest point of the inner cylinder is one-eighth to one-sixth of the diameter of the inner cylinder, and the distance between the center of the second exhaust pipe and the highest point of the inner cylinder is one-quarter to one-third of the diameter of the inner cylinder.

[0029] The control system includes a temperature control system for the rotary pyrolysis equipment and a transmission control system for the inner cylinder.

[0030] The transmission device includes an electric motor, a speed reducer, and large and small gears.

[0031] The essential features of this invention are:

[0032] (1) Based on the comprehensive thermal analysis results of the oily sludge, the pyrolysis process is divided into three stages: ambient temperature - 120℃, 120℃ - 400℃, and 400℃ - 550℃. Accordingly, the pyrolysis device is equipped with three exhaust pipes. By reasonably setting and adjusting the exhaust positions, the water, light oil and heavy oil are collected separately during the pyrolysis process.

[0033] (2) The classification and collection of products provides the possibility for subsequent classification applications.

[0034] The beneficial effects of this invention are as follows:

[0035] (1) After the first stage of pyrolysis is completed, the water vapor is extracted in time, which is beneficial to improve the quality of the recovered oil and also reduces the heat absorption in the subsequent pyrolysis process, thus improving the energy utilization efficiency.

[0036] (2) The classification and collection of pyrolysis products of light and heavy components is beneficial to purifying the composition of reactants, selecting subsequent catalysts more effectively, and improving the quality of target oil products or target gas products.

[0037] (3) The rotary pyrolysis equipment is equipped with temperature sensors to detect the temperature at each point. By controlling the flow rate of the heating medium and adjusting the opening of the flue gas valve, the temperature of the oily sludge pyrolysis is controlled in zones.

[0038] (4) The inner cylinder of the rotary pyrolysis equipment adopts frequency conversion regulation. The residence time of oily sludge can be adjusted by adjusting the rotation speed (0.5-2 rpm) to achieve better pyrolysis effect. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the classification and utilization of oily sludge resources according to the present invention.

[0040] Figure 2 This is a schematic diagram of a pyrolysis device for the classified utilization of oily sludge resources.

[0041] Figure 3 This is a schematic diagram of a pyrolysis process for the classified utilization of oily sludge resources.

[0042] Figure 4 This is the TG-DTG curve of oil sludge sample #1;

[0043] Among them, 1-feeding equipment; 2-front end connecting cover; 3-rotary pyrolysis equipment; 4-tail end connecting cover; 5-slag discharge port; 6-first exhaust pipe; 7-second exhaust pipe; 8-third exhaust pipe; 9-residue cooler; 10-transmission device; 11-storage silo; 12-rotary discharge valve; 13-screw conveyor; 31-inner cylinder; 32-outer cylinder; 33-hot flue gas inlet; 34-flue gas outlet; 35-temperature sensor; 61-steam treatment system; 71-light component treatment system; 81-heavy component treatment system. Detailed Implementation

[0044] To further understand the invention's content, features, and effects, the following embodiments are provided and detailed below, but are not limited thereto:

[0045] The apparatus for the pyrolysis process of realizing the classified utilization of oily sludge resources described in this invention, such as... Figure 2 , Figure 3 As shown, it includes a feeding device 1, a front connecting cover 2, a rotary pyrolysis device 3, a tail connecting cover 4, a slag discharge port 5, a first exhaust pipe 6, a second exhaust pipe 7, a third exhaust pipe 8, a residue cooler 9, a transmission device 10, and a control system (not shown in the figure).

[0046] The rotary pyrolysis equipment 3 has a front connecting cover 2 at the front end and a tail connecting cover 4 at the rear end, which are dynamically connected to both ends of the inner cylinder 31 respectively. The feeding equipment 1 consists of a storage bin 11, a rotary discharge valve 12, and a screw conveyor 13, and is located in front of the rotary pyrolysis equipment 3 to transport oily sludge into the rotary pyrolysis equipment 3. The slag discharge port 5 is located at the bottom of the tail connecting cover 4 of the rotary pyrolysis equipment 3, and the slag discharge port 5 is connected to the residue cooler 9. The first exhaust pipe 6 is connected to the front connecting cover 2 of the rotary pyrolysis equipment 3, and the second exhaust pipe 7 and the third exhaust pipe 8 are connected to the tail connecting cover 4 of the rotary pyrolysis equipment 3. The exhaust position of the first exhaust pipe 6 is in the water vapor generation area. The second exhaust pipe 7 and the third exhaust pipe 8 are arranged coaxially. The exhaust position of the second exhaust pipe 7 is in the light component pyrolysis product generation area, and the exhaust position of the third exhaust pipe 8 is in the heavy component pyrolysis product generation area. All exhaust ducts are connected to exhaust fans, and the positions of all exhaust ducts are adjustable (i.e., they can move left and right within the inner cylinder 31, adjusting the position of the exhaust port based on the gas temperature measured by the thermocouple inside the outer cylinder and the feedback results from the online gas chromatograph-mass spectrometer connected to the second and third exhaust ducts). The axes of the three exhaust ducts are parallel to the axis of the inner cylinder 31.

[0047] The rotary pyrolysis device 3 has a main body that is a horizontal double-layered cylinder, including an inner cylinder 31 and an outer cylinder 32 arranged concentrically. The length of the outer cylinder 32 is 70-85% of the length of the inner cylinder 31. A large gear installed on the inner cylinder 31 meshes with a small gear and is then connected to a reducer and a motor, thereby realizing the rotation of the inner cylinder. The outer cylinder 32 is fixed and does not rotate. The outer cylinder is provided with a hot flue gas inlet 33 and a flue gas outlet 34. Several temperature sensors 35 are also provided inside the outer cylinder 32. The temperature sensors 35 are electrically connected to the control device.

[0048] The oily sludge has varying moisture and oil content, therefore the exhaust pipe positions are adjustable. The first exhaust pipe is located in the water vapor generation area, corresponding to 10-40% of the inner cylinder length; the second exhaust pipe is located in the light component pyrolysis product generation area, corresponding to 45-70% of the inner cylinder length; and the third exhaust pipe is located in the heavy component pyrolysis product generation area, corresponding to 75-92% of the inner cylinder length. All are measured from the left side of the inner cylinder 31.

[0049] The distance between the center of the first exhaust pipe and the highest point of the inner cylinder is one-eighth to one-sixth of the diameter of the inner cylinder, and the distance between the center of the second exhaust pipe and the highest point of the inner cylinder is one-quarter to one-third of the diameter of the inner cylinder.

[0050] The steam treatment system 61 is connected to the outlet of the first exhaust pipe 6; after cooling the steam, it is sent to the wastewater treatment stage.

[0051] The core of the light component processing system 71 is a reaction tower or a rotary reaction device loaded with a catalyst. This system is connected to the outlet of the second exhaust pipe 7. After the light component pyrolysis products drawn out from the second exhaust pipe 7 undergo a catalytic reaction at 450-550℃, they pass through a cyclone dust collector and then enter an indirect condenser. The condensed oil products (light oil rich in chain hydrocarbons, or oil products rich in aromatic hydrocarbons) are stored in an oil storage tank, and a small amount of uncondensed pyrolysis gas is stored in a gas storage tank via a non-condensable gas fan.

[0052] The core of the heavy component processing system 81 is a reaction tower loaded with catalyst or a rotary reaction device. This system is connected to the outlet of the third exhaust pipe 8. The heavy component pyrolysis products drawn out from the third exhaust pipe 8 undergo a thermal catalytic water vapor reforming reaction at 800-1000℃, and then enter the indirect condenser after passing through a cyclone dust collector. The pyrolysis gas (small molecule gases such as H2, CO, and CH4) enters the gas storage tank for storage through a non-condensable gas fan, and the small amount of condensed pyrolysis oil products enters the oil storage tank for storage.

[0053] The control system includes temperature control of the rotary pyrolysis equipment and transmission control of the inner cylinder.

[0054] The transmission device consists of an electric motor, a reducer, and large and small gears.

[0055] The heating medium is specifically the hot flue gas produced by the hot blast furnace at 750-850℃, or any other industrial flue gas that meets the temperature requirements.

[0056] The pyrolysis process for classifying and utilizing oily sludge resources includes the following steps:

[0057] Oily sludge is stored in silo 11 and fed into rotary pyrolysis equipment 3 via rotary discharge valve 12 and screw conveyor 13. Inside rotary pyrolysis equipment 3, oily sludge moves from left to right through inner cylinder 31. At the same time, hot flue gas at 750-850℃ enters outer cylinder 32 of rotary pyrolysis equipment 3 through hot flue gas inlet 33 and moves from right to left through the inner cylinder wall to indirectly and countercurrently exchange heat with oily sludge. Finally, flue gas at 120-150℃ is discharged from outer cylinder 32 through flue gas outlet 34.

[0058] The first exhaust pipe 6 removes the water vapor generated below 120℃, the second exhaust pipe 7 removes the light component pyrolysis products generated in the temperature range of 120-400℃, and the third exhaust pipe 8 removes the heavy component pyrolysis products generated in the temperature range of 400-550℃, which are discharged from the rotary pyrolysis equipment 3 respectively.

[0059] The feed rate is 0.2–1.5 t / h; the air intake is 1000–10000 Nm³. 3 / h; the rotation speed of the inner cylinder 31 is 0.5-2 rpm;

[0060] The air inlet temperature of the outer cylinder from right to left is 750-850℃, and the air outlet temperature is 120-150℃; the temperature of the oily sludge in the inner cylinder from left to right is in the range of room temperature to 600℃.

[0061] The temperature of the gas inside the outer cylinder is indirectly reflected by the temperature of the sludge inside the outer cylinder, thus determining the positions of the first, second, and third exhaust pipes. Alternatively, an online gas chromatography-mass spectrometry (GC-MS) instrument connected to the second and third exhaust pipes can be used to determine whether the extracted product meets expectations.

[0062] Oily sludge is fed into a rotary pyrolysis unit 3 at a certain feed rate via a rotary discharge valve 12 and a screw conveyor 13 in a storage silo 11. Inside the rotary pyrolysis unit 3, the oily sludge flows through the inner cylinder 31, while the heating medium flows through the outer cylinder 32. The oily sludge and heating medium achieve counter-current indirect heat exchange, causing a pyrolysis reaction. The first exhaust pipe 6 removes water vapor generated below 120℃, the second exhaust pipe 7 removes light component pyrolysis products generated in the temperature range of 120-400℃, and the third exhaust pipe 8 removes heavy component pyrolysis products generated in the temperature range of 400-550℃. These products are then discharged from the rotary pyrolysis unit 3. While the oily sludge is pyrolyzing in the rotary pyrolysis unit 3, it moves towards the tail end of the inner cylinder 31. The remaining pyrolysis residue is discharged through the slag discharge port 5 at the tail end of the rotary pyrolysis unit 3 and enters the residue cooler 9. After cooling, it can be used as a building material raw material. The steam extracted from the first exhaust duct 6 enters the steam treatment system 61. The pyrolysis products of the light components extracted from the second exhaust duct 7 enter the light component treatment system 71, where catalytic pyrolysis occurs at 450-550℃ under the action of different catalysts to obtain light oil rich in chain hydrocarbons, or oil products rich in aromatic hydrocarbons. A small amount of non-condensable gas can be collected and used as gaseous fuel. The pyrolysis products of the heavy components extracted from the third exhaust duct 8 enter the heavy component treatment system 81, where a thermocatalytic steam reforming reaction occurs at 800-1000℃, producing mostly small molecule gases such as H2, CO, and CH4, with a small amount becoming pyrolysis oil products.

[0063] Example 1

[0064] In this embodiment, the No. 1 oily sludge was treated by using the Dean-Stark azeotropic distillation method to separate and measure the three components of water, oil and residue. The oily sludge sample had a water content of 1.5%, an oil content of 71.5%, and a residue content of 27.0%.

[0065] The figure shows the TG-DTG image of oily sludge sample #1 at a heating rate β = 10℃ / min. The pyrolysis of the sample can be divided into four stages: Stage 1, in the temperature range of 40–120℃, involves the oily sludge absorbing heat and evaporating its own moisture. This process is relatively slow, and because the oily sludge sample was dried before the thermogravimetric experiment, the weight loss in this stage is small, at 0.77%. Stage 2, in the temperature range of 120–414℃, mainly involves the precipitation of light components, with a weight loss of 64.30%. Stage 3, mainly involves the cracking of heavy components, in the temperature range of 414–540℃, where the remaining organic matter in the oily sludge undergoes cracking and recombination, with a weight loss of 7.31%. Stage 4, in which the TG curve shows no significant decrease, indicates that pyrolysis is basically complete, mainly involving the decomposition of minerals, in the temperature range of 646–788℃, with a weight loss of 3.15%.

[0066] Oily sludge #1 is fed into the rotary pyrolysis equipment 3 (inner cylinder rotation speed is 1.3 rpm) at a feed rate of 1 t / h via rotary discharge valve 12 and screw conveyor 13 in storage silo 11. Inside the rotary pyrolysis equipment 3, the oily sludge flows through the inner cylinder 31, while 800℃ hot flue gas, the heating medium, enters the outer cylinder 32 of the rotary pyrolysis equipment 3 through hot flue gas inlet 33 (inlet air volume 6000 Nm³). 3 The oily sludge undergoes countercurrent indirect heat exchange with the heating medium ( / h), resulting in a pyrolysis reaction. Finally, the flue gas at 120–150°C is discharged from the flue gas outlet 34 into the outer cylinder 32. The inner cylinder has dimensions of Φ1.6 × 16.5 m, and the outer cylinder has dimensions of Φ2.0 × 14 m. The distance between the center of the first exhaust pipe and the highest point of the inner cylinder is one-seventh of the inner cylinder diameter, and the distance between the center of the second exhaust pipe and the highest point of the inner cylinder is one-third of the inner cylinder diameter. The first exhaust pipe 6 removes water vapor at approximately 100℃ at a depth of 5.94m (the condensed mass is 0.021t / h). The second exhaust pipe 7 removes the pyrolysis products of the light components at approximately 400℃ at a depth of 11.22m (corresponding to a condensed liquid mass of 0.534t / h and a gas mass of 0.053t / h). The third exhaust pipe 8 removes the pyrolysis products of the heavy components at approximately 550℃ at a depth of 14.19m (corresponding to a condensed liquid mass of 0.059t / h and a gas mass of 0.027t / h), and these products are discharged from the rotary pyrolysis unit 3. The oily sludge undergoes pyrolysis in the rotary pyrolysis unit 3 while simultaneously moving towards the tail end of the inner cylinder 31. The remaining pyrolysis residue is discharged through the slag discharge port 5 at the tail end of the rotary pyrolysis unit 3 and enters the residue cooler 9. After cooling, it can be used as a raw material for building materials. The pyrolysis residue yield is 0.306 t / h, with an oil content of 0.15%.

[0067] Although preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the scope of protection of the present invention. Matters not covered in this invention are common knowledge.

Claims

1. A pyrolysis process for the classified utilization of oily sludge resources, characterized in that: The process includes the following steps: Oily sludge at room temperature in the storage silo is fed into the inner cylinder of the rotary pyrolysis equipment via a rotary discharge valve and screw conveyor; the oily sludge moves from left to right through the inner cylinder; at the same time, a heating medium at 750-850℃ enters the outer cylinder of the rotary pyrolysis equipment and, from right to left, exchanges heat indirectly and countercurrently with the oily sludge through the inner cylinder wall; finally, flue gas at 120-150℃ is discharged from the outer cylinder through the flue gas outlet. The first exhaust pipe removes the generated water vapor, the second exhaust pipe removes the light component pyrolysis products generated in the temperature range of 120-400℃, and the third exhaust pipe removes the heavy component pyrolysis products generated in the temperature range of 400-550℃, which are then discharged from the inner cylinder. The heating medium is industrial flue gas; A device for realizing the classified utilization of oily sludge resources through pyrolysis, the device includes a feeding device, a front-end connecting cover, a rotary pyrolysis device, a tail-end connecting cover, a slag discharge port, a first exhaust pipe, a second exhaust pipe, a third exhaust pipe, a transmission device, and a control system. The rotary pyrolysis equipment has a front connecting cover at the front end and a tail connecting cover at the rear end, which are dynamically connected to both ends of the inner cylinder. The feeding equipment consists of a storage bin, a rotary discharge valve, and a screw conveyor, located in front of the rotary pyrolysis equipment, and transports oily sludge into the equipment. The discharge port is located at the bottom of the tail connecting cover and is connected to the residue cooler. The first exhaust pipe is connected to the front connecting cover, and the second and third exhaust pipes are connected to the tail connecting cover. The first exhaust pipe is located in the steam generation area. The second and third exhaust pipes are coaxially arranged, with the second exhaust pipe located in the light component pyrolysis product generation area and the third exhaust pipe located in the heavy component pyrolysis product generation area. All exhaust pipes are connected to an induced draft fan. The rotary pyrolysis equipment is a horizontal double-layered cylinder consisting of an inner cylinder and an outer cylinder arranged concentrically. The length of the outer cylinder is 70-85% of the length of the inner cylinder. A large gear installed on the inner cylinder meshes with a small gear, which in turn connects to a reducer and a motor, thereby enabling the rotation of the inner cylinder. The outer cylinder is fixed and does not rotate. The outer cylinder is equipped with a hot flue gas inlet and a flue gas outlet. Several temperature sensors are also installed inside the outer cylinder. The temperature sensors are electrically connected to the control device. The first exhaust duct is located in the water vapor generation area, corresponding to 10-40% of the inner cylinder length; the second exhaust duct is located in the light component pyrolysis product generation area, corresponding to 45-70% of the inner cylinder length; the third exhaust duct is located in the heavy component pyrolysis product generation area, corresponding to 75-92% of the inner cylinder length. The position of all exhaust pipes can be adjusted by moving them left and right within the inner cylinder.

2. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that: The heating medium is the hot flue gas produced by the hot blast stove.

3. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that the oily sludge entering the feeding equipment has the following characteristics: water content of 0-10%; oil content of 50-90%; slag content of 5-40%; and all percentages of the materials are mass percentages.

4. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that the feed rate is 0.2~1.5 t / h; and the air intake is 1000~10000 Nm³. 3 / h; the rotation speed of the inner cylinder is 0.5-2 rpm.

5. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that: The light component pyrolysis products undergo catalytic pyrolysis at 450-550℃ under the action of different catalysts to obtain light oil rich in chain hydrocarbons, or to obtain oil products rich in aromatic hydrocarbons. The pyrolysis products of the heavy components undergo a thermocatalytic water vapor reforming reaction at 800-1000℃ to generate H2, CO and CH4; The pyrolysis residue has an oil content of less than 0.3% and its main components are SiO2, Fe2O3, Al2O3, and CaO. It is used as a raw material for building materials.

6. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that, In the device, the diameter of the inner cylinder ranges from 1.4 to 3.0 m, and the length ranges from 6.0 to 18.0 m.

7. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that, In the device, the distance between the center of the first exhaust pipe and the highest point of the inner cylinder is one-eighth to one-sixth of the diameter of the inner cylinder, and the distance between the center of the second exhaust pipe and the highest point of the inner cylinder is one-quarter to one-third of the diameter of the inner cylinder.

8. The pyrolysis process for classifying and utilizing oily sludge resources as described in claim 1, characterized in that, The control system in the device includes a temperature control system for the rotary pyrolysis equipment and a transmission control system for the inner cylinder.

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