Harmless treatment system for realizing oil production by hydrothermal liquefaction of oily waste and supercritical water oxidation step by step and starting control method thereof

Abstract

The invention relates to a system for realizing oil production by hydrothermal liquefaction of oil-containing waste and supercritical water oxidation innocent treatment step by step and a start control method thereof, and the start control method specifically comprises the following steps: conveying a material to a primary heater through a material pump to heat, after reaching 350 DEG C, entering a secondary heater to maintain the temperature, then entering a reactor to perform hydrothermal liquefaction, and recovering an oil product; the liquefied waste liquid is subjected to supercritical water oxidation treatment, the oxidized waste liquid generates carbon dioxide and water, and the carbon dioxide and the water enter a cooler through an oxidation valve and then are discharged. In order to realize quick start, the invention provides two start modes: one mode is heating by injecting steam into the reactor, and the other mode is starting to heat materials through back pressure, and quick heating is realized by combining external heat tracing and cooling water. In addition, under the supercritical water oxidation working condition, stable operation of the reactor is ensured through accurate temperature and pressure control. According to the method, the starting time is effectively shortened, the treatment efficiency is improved, and good environmental protection and economic benefits are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste treatment, and specifically relates to a system for realizing step-by-step hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation harmless treatment, and also relates to a startup control method for realizing step-by-step hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation harmless treatment. Background Art

[0002] With the advancement of industrialization, the amount of oily waste generated has increased year by year. Traditional methods of treating oily waste, such as incineration and landfill, are prone to secondary pollution and have low treatment efficiency, and cannot effectively achieve resource recovery and harmless waste discharge. Therefore, it is particularly important to develop an efficient and environmentally friendly treatment technology.

[0003] Hydrothermal liquefaction is an advanced technology that uses the properties of water under high temperature and pressure to convert organic matter into recyclable oil products. In the subcritical water or supercritical water state, water can act as a solvent and catalyst to react chemically with organic matter in waste to produce oil products and other valuable chemicals. However, the waste liquid after hydrothermal liquefaction often contains a large amount of organic matter and cannot be discharged directly. It must be further treated to avoid environmental pollution.

[0004] Supercritical water oxidation (SCWO) technology is a harmless treatment technology that uses water as a reaction medium in a supercritical state to oxidize organic matter in waste liquid into carbon dioxide and water. This technology has the advantages of high efficiency, thoroughness, and environmental protection. It can treat difficult-to-degrade organic matter, and the reaction conditions are relatively mild, making it suitable for industrial applications. However, existing supercritical water oxidation systems have problems such as difficulty in starting up and slow temperature rise, resulting in long system startup time and slow startup speed, which in turn affects the efficiency of the entire treatment process.

[0005] Therefore, how to achieve rapid heating and efficient startup during hydrothermal liquefaction and supercritical water oxidation while ensuring stable operation of the system is a key issue that needs to be urgently solved in current technology. Summary of the invention

[0006] The first purpose of the present invention is to provide a system for realizing the hydrothermal liquefaction of oil-containing waste and the harmless treatment of supercritical water oxidation in steps, so as to solve the problems of long startup time and slow startup speed of sub-supercritical equipment in the startup process in the prior art, thereby improving the processing efficiency and ensuring the rapid startup and stable operation of the equipment.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A system for stepwise realizing hydrothermal liquefaction of oily waste to produce oil and supercritical water oxidation for harmless treatment includes a material tank, a reactor, a cooler, a cooling water tank and a combustion improver tank; the discharge port of the material tank is sequentially connected to the inlet of the reactor through a material pump, a primary heater and a secondary heater, the reactor is connected to the inlet of the cooler through a discharge valve, the outlet of the cooler is connected to the outside through a back pressure valve, the cooling water tank is connected with a cooling water pump, and the cooling water pump is respectively communicated with the cavities in the inner walls of the reactor and the cooler through a first cooling water reactor inlet valve and a second cooling water reactor inlet valve, the cavity of the cooler is respectively connected with a material tank preheating inlet valve and a cooling water bypass valve, the material tank preheating inlet valve is communicated with the cavity in the inner wall of the material tank, the cavity of the reactor is connected with a cooling water reactor outlet valve, and the cooling water reactor outlet valve is respectively connected with the material tank preheating inlet valve and the cooling water bypass valve; the combustion improver tank is sequentially connected to the inlet of the reactor through a combustion improver pump and a combustion improver outlet valve.

[0008] The technical solution of the present invention also has the following characteristics: The material tank is interlocked and controlled with the material tank preheating inlet valve through a material tank temperature controller.

[0009] The primary heater is interlocked and controlled with a primary heater temperature controller.

[0010] The secondary heater is interlocked and controlled with a secondary heater temperature controller.

[0011] During the hydrothermal liquefaction process for producing oil, the secondary heater is used as supplementary heating to ensure that the temperature of the output material is 350 °C.

[0012] During the supercritical water oxidation process for harmless treatment, the secondary heater is used as secondary heating to heat the temperature of the material to 450 °C.

[0013] The second object of the present invention is to provide a start-up control method for a system for stepwise realizing hydrothermal liquefaction of oily waste to produce oil and supercritical water oxidation for harmless treatment, so as to solve the problems of long start-up time and slow start-up speed of sub-supercritical equipment in the prior art during the start-up process, thereby improving the treatment efficiency and ensuring the rapid start-up and stable operation of the equipment.

[0014] In order to achieve the above object, the first technical solution adopted by the present invention is as follows: For the start-up control method of a system for stepwise realizing hydrothermal liquefaction of oily waste to produce oil and supercritical water oxidation for harmless treatment, when there is no pressure in the system, the material is heated into steam at 350 °C by the primary heater and injected into the reactor, and the reactor is rapidly heated by the steam releasing the gasification latent heat. When the temperature of the reactor wall reaches 300 °C, back pressure treatment is carried out to complete the system heating. Under the system backpressure condition, when the pressure reaches 25 MPa, start the first-stage heater to heat the material to 350 °C and inject it into the reactor. At the same time, use the tracing heating system and cooling water to assist in temperature rise, and finally realize the system temperature rise.

[0015] In order to achieve the above object, the second technical solution adopted by the present invention is: a start-up control method for realizing the hydrothermal liquefaction of oily waste to produce oil and the harmless treatment of supercritical water oxidation step by step. Under the supercritical water oxidation condition, when the system pressure reaches 25 MPa, the material is heated to above 450 °C through the first-stage heater and injected into the reactor. At the same time, the oxidant is injected into the reactor through the oxidant pump to carry out a counter-jet ignition reaction with the material. After the material catches fire, it releases energy to maintain the continuous progress of the reaction. At the same time, the reactor wall is protected by the cooling water system to prevent overheating.

[0016] The beneficial effects of the present invention are: The step-by-step realization of the hydrothermal liquefaction of oily waste to produce oil and the harmless treatment of supercritical water oxidation system of the present invention provides a start-up control technology for realizing the hydrothermal liquefaction of oily waste to produce oil and the harmless treatment of supercritical water oxidation step by step for the problems of long start-up time and slow start-up speed of sub-supercritical equipment during the start-up process. It can be quickly started under different working conditions and efficiently complete the waste treatment process, which not only improves the treatment efficiency but also reduces the energy consumption, and has good environmental and economic benefits. Description of the Drawings

[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 is a structural schematic diagram of a step-by-step realization of the hydrothermal liquefaction of oily waste to produce oil and the harmless treatment of supercritical water oxidation system of the present invention.

[0018] In the figure, 1. material tank; 2. material pump; 3. first-stage heater; 4. second-stage heater; 5. reactor; 6. discharge valve; 7. cooler; 8. backpressure valve; 9. combustion improver tank; 10. combustion improver pump; 11. combustion improver outlet valve; 12. cooling water tank; 13. cooling water pump; 14. first cooling water reactor inlet valve; 15. second cooling water reactor inlet valve; 16. cooling water reactor outlet valve; 17. material tank preheating inlet valve; 18. cooling water bypass valve; T01. material tank temperature controller; T02. first-stage heater temperature controller; T03. second-stage heater temperature controller. Detailed Embodiments

[0019] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0020] In the description of the present invention, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0021] Embodiment 1 As Figure 1 shown, a step-by-step system for hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation for harmless treatment according to the present invention includes a material tank 1, a reactor 5, a cooler 7, a cooling water tank 12, and a combustion improver tank 9.

[0022] The outlet of the material tank 1 is sequentially connected to the inlet of the reactor 5 through a material pump 2, a primary heater 3, and a secondary heater 4. The reactor 5 is connected to the inlet of the cooler 7 through a discharge valve 6. The outlet of the cooler 7 is connected to the outside through a back pressure valve 8. The cooling water tank 12 is connected with a cooling water pump 13. The cooling water pump 13 is respectively connected to the cavities in the inner walls of the reactor 5 and the cooler 7 through a first cooling water reactor inlet valve 14 and a second cooling water reactor inlet valve 15. The cavities of the cooler 7 are respectively connected with a material tank preheating inlet valve 17 and a cooling water bypass valve 18. The material tank preheating inlet valve 17 is connected to the cavity in the inner wall of the material tank 1. The cavity of the reactor 5 is connected with a cooling water reactor outlet valve 16. The cooling water reactor outlet valve 16 is respectively connected to the material tank preheating inlet valve 17 and the cooling water bypass valve 18. The combustion improver tank 9 is sequentially connected to the inlet of the reactor 5 through a combustion improver pump 10 and a combustion improver outlet valve 11.

[0023] Among them: The material tank 1 is used to store oil-containing waste; The material pump 2 is used to send the material from the material tank 1 into the primary heater 3; The primary heater 3 is used to heat the material to 350 °C; The secondary heater 4 is used to supplement heat to the material and heat the material to 350 °C to 450 °C; The reactor 5 is used for waste oil recovery and upgrading under subcritical hydrothermal conditions, or for harmless treatment of waste liquid under supercritical water oxidation conditions; The discharge valve 6 is used to control the flow direction of the liquefied and oxidized material; The cooler 7 is used to cool the reacted material; Cooling equipment consisting of a cooling water tank 12, a cooling water pump 13, a first cooling water inlet valve 14, a second cooling water outlet valve 13, etc. is used to cool the system and ensure the safe operation of the equipment.

[0024] During operation, the material is sent from the material tank 1 to the first-stage heater 3 by the material pump 2, heated to 350 °C, enters the second-stage heater 4 for supplementary heating, and then enters the reactor 5.

[0025] When the hydrothermal liquefaction process to produce oil is carried out in the reactor 5: The material is transported from the material tank 1 to the first-stage heater 3 by the material pump 2 for heating. When the material temperature rises to 350 °C, it enters the second-stage heater 4 for supplementary heating to keep the outlet temperature of the material at 350 °C. Then, the material is transported to the reactor 5 for hydrothermal liquefaction reaction to recover oil products. After the hydrothermal liquefaction reaction, the material enters the cooler 7 through the discharge valve 6 for cooling and is discharged through the back pressure valve 8.

[0026] When the supercritical water oxidation harmless treatment process is carried out in the reactor 5: For the waste liquid after hydrothermal liquefaction, the organic matter that cannot be directly discharged is treated by supercritical water oxidation. In this process, the material is heated to 350 °C by the first-stage heater 3, then heated to 450 °C by the second-stage heater 4, and the combustion aid in the combustion aid tank 9 is injected into the reactor through the combustion aid pump 10 to carry out supercritical water oxidation reaction with the organic matter in the waste liquid to generate carbon dioxide and water. After the supercritical water oxidation reaction ends, the oxidized material enters the cooler 7 through the discharge valve 6 and is discharged through the back pressure valve 8.

[0027] In addition, the step-by-step implementation of the system for hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation harmless treatment of the present invention further includes a set of cooling water system and temperature control system to ensure the stable operation of each device and avoid potential safety hazards caused by too high or too low temperature. Specifically, during operation, the cooling water in the cooling water tank 12 is introduced into the cavities in the inner walls of the reactor 5 and the cooler 7 respectively by the cooling water pump 13 for cooling.

[0028] Example 2 As Figure 1 shown, different from Example 1, in the system for step-by-step implementation of hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation harmless treatment of the present invention in this Example 2: The material tank 1 is interlocked and controlled with the material tank preheating inlet valve 17 through the material tank temperature controller T01.

[0029] When the material tank preheating inlet valve 17 controls the outflow of cooling water, the temperature of the material tank 1 can be maintained at 80 °C.

[0030] Example 3 As Figure 1As shown, different from Example 2, in a step-by-step implementation of an oil-containing waste hydrothermal liquefaction to produce oil and supercritical water oxidation harmless treatment system of the present invention in Example 3: The primary heater 3 is interlocked and controlled with the primary heater temperature controller T02; the secondary heater 4 is interlocked and controlled with the secondary heater 4 through the secondary heater temperature controller T03.

[0031] The primary heater 3 is interlocked and controlled with the primary heater 3 through the primary heater temperature controller T02 to maintain the outlet temperature of the primary heater 3 at 350 °C.

[0032] The secondary heater 4 is interlocked and controlled with the secondary heater 4 through the secondary heater temperature controller T03; to maintain the outlet temperature of the secondary heater 4 at 350 °C under the liquefaction condition and 450 °C under the supercritical water oxidation condition.

[0033] Example 4 As Figure 1 shown, different from Example 2, in a step-by-step implementation of an oil-containing waste hydrothermal liquefaction to produce oil and supercritical water oxidation harmless treatment system of the present invention in Example 4: The secondary heater 4 is interlocked and controlled with the secondary heater 4 through the secondary heater temperature controller T03.

[0034] The secondary heater 4 is interlocked and controlled with the secondary heater 4 through the secondary heater temperature controller T03; to maintain the outlet temperature of the secondary heater 4 at 350 °C under the liquefaction condition and 450 °C under the supercritical water oxidation condition.

[0035] Example 5 Combined with Figure 1 , for a start-up control method of a step-by-step implementation of an oil-containing waste hydrothermal liquefaction to produce oil and supercritical water oxidation harmless treatment system of the present invention, when using the hydrothermal liquefaction to produce oil process for start-up control in the reactor 5: When the system has no pressure, the material is heated into steam at 350 °C by the primary heater 3 and injected into the reactor 5, and the reactor 5 is rapidly heated by the release of the gasification latent heat of the steam. When the wall temperature of the reactor 5 reaches 300 °C, backpressure treatment is carried out to complete the system heating; Under the backpressure condition of the system, when the pressure reaches 25 MPa, start the primary heater 3 to heat the material to 350 °C and inject it into the reactor 5, and at the same time, assist the heating through the tracing system and cooling water to finally achieve system heating.

[0036] Example 6 Combined with Figure 1 , for a start-up control method of a step-by-step implementation of an oil-containing waste hydrothermal liquefaction to produce oil and supercritical water oxidation harmless treatment system of the present invention, when using the supercritical water oxidation harmless treatment process for start-up control in the reactor 5: In the supercritical water oxidation process, when the pressure reaches 25 MPa, the material is heated to above 250 °C by a primary heater and injected into the reactor. At the same time, the oxidant pump is started to inject the oxidant into the reactor for counter-jet ignition reaction with the material. After the material catches fire, a large amount of energy is released to maintain the continuous progress of the reaction. At this time, the cooling water system is started to protect the reactor wall to prevent overheating.

[0037] Therefore, a system for stepwise realizing hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation for harmless treatment according to the present invention provides a start-up control technology for stepwise realizing hydrothermal liquefaction to produce oil and supercritical water oxidation for harmless treatment, aiming at the problems of long start-up time and slow start-up speed of sub-supercritical equipment during the start-up process. It can be quickly started under different working conditions and efficiently complete the waste treatment process, which not only improves the treatment efficiency but also reduces energy consumption, having good environmental and economic benefits.

[0038] The above description shows and describes several preferred embodiments of the invention. However, as mentioned above, it should be understood that the invention is not limited to the forms disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the inventive concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the invention shall fall within the protection scope of the appended claims of the invention.

Claims

1. A system for step - by - step realizing hydrothermal liquefaction of oily waste to produce oil and supercritical water oxidation for harmless treatment, characterized in that, It includes a material tank. The discharge port of the material tank is sequentially connected to the inlet of the reactor through a material pump, a primary heater, and a secondary heater. The reactor is connected to the inlet of the cooler through a discharge valve. The outlet of the cooler is connected to the outside through a backpressure valve. A cooling water tank is connected with a cooling water pump. The cooling water pump is respectively connected to the cavities in the inner walls of the reactor and the cooler through a first cooling water reactor inlet valve and a second cooling water reactor inlet valve. The cavity of the cooler is respectively connected with a material tank preheating inlet valve and a cooling water bypass valve. The material tank preheating inlet valve is connected to the cavity in the inner wall of the material tank. The cavity of the reactor is connected with a cooling water reactor outlet valve. The cooling water reactor outlet valve is respectively connected to the material tank preheating inlet valve and the cooling water bypass valve; The combustion-supporting agent tank is sequentially connected to the inlet of the reactor through a combustion-supporting agent pump and a combustion-supporting agent outlet valve.

2. The step-by-step implementation of the hydrothermal liquefaction of oily waste to produce oil and the supercritical water oxidation harmless treatment system according to claim 1, wherein, The material tank (1) is interlocked and controlled with the material tank preheating inlet valve (17) through a material tank temperature controller (T01).

3. The step-by-step implementation of the hydrothermal liquefaction of oily waste to produce oil and the supercritical water oxidation harmless treatment system according to claim 2, characterized in that, The primary heater (3) is interlocked and controlled with a primary heater temperature controller (T02).

4. The step-by-step implementation of the hydrothermal liquefaction of oily waste to produce oil and the supercritical water oxidation harmless treatment system according to claim 3, characterized in that, The secondary heater (4) is interlocked and controlled with a secondary heater temperature controller (T03).

5. The step-by-step implementation of the hydrothermal liquefaction of oily waste to produce oil and the supercritical water oxidation harmless treatment system according to claim 4, characterized in that, During the hydrothermal liquefaction process for producing oil, the secondary heater (4) is used for supplementary heating to ensure that the temperature of the output material is 350 °C.

6. The step-by-step implementation of the hydrothermal liquefaction of oily waste to produce oil and the supercritical water oxidation harmless treatment system according to claim 5, characterized in that, During the supercritical water oxidation process for harmless treatment, the secondary heater (4) is used for secondary heating to heat the temperature of the material to 450 °C.

7. The starting control method for the step-by-step realization of the system for hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation for harmless treatment according to any one of claims 1-6, characterized in that When there is no pressure in the system, the material is heated into steam at 350 °C by the primary heater (3) and injected into the reactor (5). The reactor (5) is rapidly heated by releasing the gasification latent heat of the steam. When the wall temperature of the reactor (5) reaches 300 °C, backpressure treatment is carried out to complete the system heating; Under the backpressure condition of the system, when the pressure reaches 25 MPa, the primary heater (3) is started to heat the material to 350 °C and inject it into the reactor (5), and at the same time, the system is heated by the tracing system and cooling water to finally realize the system heating.

8. The starting control method for the step-by-step realization of the system for hydrothermal liquefaction of oil-containing waste to produce oil and supercritical water oxidation for harmless treatment according to any one of claims 1-7, characterized in that Under the supercritical water oxidation working condition, when the system pressure reaches 25 MPa, the material is heated to above 450 °C by the primary heater (3) and injected into the reactor (5). At the same time, the oxidant is injected into the reactor (5) through the oxidant pump (10) to have a counter-jet ignition reaction with the material. After the material catches fire, it releases energy to maintain the continuous progress of the reaction. At the same time, the wall of the reactor (5) is protected by the cooling water system to prevent overheating.

Images