Non-catalytic partial oxidation-reforming reaction decoking method and system

Abstract

According to the non-catalytic partial oxidation-reforming reaction decoking method and the system thereof disclosed by the invention, a two-stage pure oxygen environment is arranged in the reforming furnace, so that tar-containing synthesis gas is subjected to a sufficient pure oxygen combustion reaction at 1350 DEG C continuously, tar is fully cracked, and the tar is fully decomposed; the reformed high-temperature synthesis gas is subjected to heat exchange, separation, heat exchange, filtration and washing in sequence, and the final synthesis gas enters the next working section to be subjected to separation transformation; wherein heat exchange water and superheated steam are generated through multi-stage heat recovery and can also be circularly used for a front-end gasification or pyrolysis system or a byproduct superheated steam, so that good economical efficiency is achieved, and part of synthesis gas subjected to multi-stage heat exchange serves as chilling synthesis gas to be circularly utilized to the front end to be converged with synthesis gas subjected to radiation heat exchange; a low-temperature cooling synthesis gas chilling mode is fully utilized, and the sensible heat of the synthesis gas is utilized to the maximum extent; the whole combustor has the advantages of being simple in structure, easy to operate, good in mixing performance and stable in combustion.

Description

Technical Field

[0001] The invention relates to a biomass gasification decoking technology, in particular to a non-catalytic partial oxidation-reforming reaction decoking method and a system thereof. Background Art

[0002] Biomass is an important renewable energy source with a wide distribution and huge quantity. Biomass gasification is a process in which the organic polymers of biomass undergo pyrolysis, oxidation, reduction and reforming reactions under certain thermodynamic conditions with the help of part of the air (or oxygen) and water vapor, and are finally converted into combustible gases such as carbon monoxide, hydrogen and low molecular hydrocarbons. The biggest difficulty in the biomass gasification process is the formation of tar during the reaction. After condensation, the tar will adhere to the reaction system, causing corrosion to the equipment, and it is difficult to directly apply it to the subsequent process, so the tar must be removed as much as possible.

[0003] At present, decoking methods can be generally divided into two categories: physical method and thermochemical method. Physical decoking does not actually remove tar, but transfers tar from gas phase to condensed phase. It is a transfer of the problem, not really removing tar. It mainly includes wet or dry-wet decoking, dry decoking, etc. Thermochemical decoking is to make tar undergo a series of chemical reactions under certain reaction conditions, so that the macromolecular tar is converted into small molecular useful gas. Therefore, thermochemical decoking not only removes tar fundamentally, eliminates the hidden dangers of tar damage to equipment and environmental pollution, but also can effectively recover energy.

[0004] Thermochemical decoking mainly includes thermal cracking decoking and catalytic cracking decoking. For the tar cracking process of the thermochemical method, the cracking temperature must reach above 1100°C for effective cracking. However, to reach a high temperature of above 1100°C, not only the material requirements of the cracking equipment itself are very high, but also good insulation equipment is required. Overall research and analysis show that the current tar pyrolysis methods generally have problems such as high equipment cost and high power consumption. Therefore, the current process equipment still has the problem of relative waste of resources and environmental pollution. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method and system for decoking a non-catalytic partial oxidation-reforming reactor. The method greatly simplifies the pyrolysis reforming process by mixing pure oxygen with synthesis gas tar for combustion reforming. Moreover, through good mixing and efficient reforming, part of the synthesis gas is used in the furnace to completely pyrolyze tar and methane.

[0006] The technical solution of the present invention is as follows: A method for decoking by non-catalytic partial oxidation-reforming reaction, wherein the decoking process is as follows: The tar-containing synthesis gas and oxygen enter the reforming furnace separately. The reforming furnace is arranged vertically. The synthesis gas and the primary oxygen source enter the furnace from the upper end and undergo pure oxygen combustion reaction at the throat of the reforming furnace. After the reaction, the temperature of the synthesis gas located at the upper part of the reforming furnace should reach at least 1350°C, providing suitable oil pyrolysis temperature conditions; then, when the high-temperature synthesis gas flows through the middle part of the reforming furnace, it undergoes pure oxygen combustion reaction again with the secondary oxygen source entering the reforming furnace to supplement heat and maintain the temperature of the high-temperature synthesis gas at 1350~1400°C; the tar is fully cracked in the furnace; then, the high-temperature synthesis gas flows out from the outlet below the side wall of the reforming furnace, and some large particles of ash in the synthesis gas are discharged from the slag discharge port at the bottom of the furnace body due to inertia; The high-temperature synthesis gas after reforming undergoes radiation heat exchange and then ash separation. The synthesis gas after ash separation undergoes multi-stage convection heat exchange in turn. The synthesis gas after heat exchange is subjected to dust separation, and then acid and dust are removed through an alkaline washing process, and finally enters the next stage for separation and transformation.

[0007] Furthermore, the synthesis gas enters the reformer furnace longitudinally from the top, and the primary oxygen source enters the furnace obliquely downward from the throat of the reformer furnace. The oxygen as a whole obliquely wraps the synthesis gas flowing in longitudinally, forming a pure oxygen environment wrapped in a circular shape, so that the synthesis gas and the primary oxygen undergo a pure oxygen combustion reaction. Therefore, the temperature of the synthesis gas after the reaction can reach 1350°C in the upper furnace, thereby achieving the cracking of tar in the synthesis gas.

[0008] Furthermore, when the high-temperature synthesis gas in the upper furnace flows downward and passes through the middle section of the furnace body, the secondary oxygen source enters the furnace obliquely downward from the waist of the reforming furnace, and again obliquely wraps the synthesis gas flowing longitudinally as a whole, so that the synthesis gas and the secondary oxygen undergo pure oxygen combustion reaction again. Therefore, the synthesis gas temperature in the lower furnace can be continuously maintained at 1350°C, allowing the tar to be fully cracked.

[0009] Furthermore, the heat exchange water of the radiation heat exchange flows into the steam drum, and then flows out through the steam drum to form a saturated water circulation loop.

[0010] Furthermore, the hot water of the multi-stage convective heat exchange flows into the steam drum through the pipeline, the saturated steam after steam-water separation in the steam drum is uniformly returned to the first-stage convective heat exchange pipeline as heat exchange steam, and the saturated water after steam-water separation in the steam drum is returned to the last-stage convective heat exchange pipeline as hot water, forming a saturated water circulation loop.

[0011] Furthermore, all the hot water flows into the same steam drum to form corresponding circulation loops.

[0012] Further, the drum is provided with a supplementary source of desalted water.

[0013] Furthermore, the temperature of the synthesis gas after radiation heat exchange is reduced to 800°C.

[0014] A decoking system suitable for the above-mentioned non-catalytic partial oxidation-reforming reaction decoking method specifically comprises: a reforming furnace, a radiation waste boiler, a multi-stage separator, a multi-stage convection waste boiler, a filter, a scrubber, a steam drum, and a compressor; The top of the reforming furnace is provided with a syngas inlet, and the lower side wall of the reforming furnace body is provided with a syngas outlet, which is connected to the inlet of the radiation waste boiler through a pipeline through the syngas outlet, the heat exchange syngas outlet of the radiation waste boiler is connected to the inlet of the multi-stage separator through a pipeline, the syngas outlet of the multi-stage separator is connected to the syngas inlet of the multi-stage convection waste boiler, the syngas outlet of the multi-stage convection waste boiler is connected to the gas inlet of the filter through a pipeline, and the filtered syngas is connected to the syngas conversion process through a pipeline; The hot water of the radiation waste boiler and the hot water of the multi-stage convection waste boiler are connected to the steam drum through different pipelines respectively. After the hot water is separated into steam and water in the steam drum, a part of the saturated water flows back to the radiation waste boiler through the pipeline as a heat exchange medium, and the other part of the saturated water and the saturated steam flow into different convection waste boilers of the multi-stage convection waste boiler as heat exchange medium.

[0015] Furthermore, the throat of the reforming furnace is provided with an oxygen inlet 1, the waist of the reforming furnace is provided with an oxygen inlet 2, and the bottom of the reforming furnace body is provided with a slag discharge port. The number and angle of the oxygen inlets 1 and 2 need to be designed in detail and accurately according to the pure oxygen flow rate and the diameter of the reforming furnace.

[0016] Furthermore, the oxygen inlet 1 and the oxygen inlet 2 are both provided with pure oxygen nozzles inclined downward; oxygen enters the furnace through the nozzles, wraps around the synthesis gas, and is fully mixed with the synthesis gas.

[0017] Furthermore, the oxygen inlet 1 and the oxygen inlet 2 are respectively arranged in a ring shape inside the reforming furnace body.

[0018] Furthermore, the multi-stage convection waste boiler includes convection waste boiler one and convection waste boiler two, the saturated steam after drum heat exchange is used as the heat exchange medium of convection waste boiler one, and the partially saturated water after drum heat exchange is used as the heat exchange medium of convection waste boiler two.

[0019] Furthermore, the superheated steam after heat exchange in the convection waste boiler one is provided to users through a pipeline, and the synthesis gas after heat exchange enters the convection waste boiler two; the synthesis gas after heat exchange in the convection waste boiler two is divided into two paths, one path enters the filter, and the other path is connected to the pipeline of the radiation waste boiler synthesis gas outlet through a pipeline arranged with a compressor, that is, part of the synthesis gas that has undergone multi-stage convection waste boiler heat exchange is used as quenching synthesis gas and merges with the synthesis gas after radiation heat exchange.

[0020] Furthermore, the steam drum is also provided with a desalted water supplement pipeline for water vapor balance in the steam drum.

[0021] Furthermore, an ash outlet is provided at the bottom of the multi-stage separator and is connected to an ash discharge process through a pipeline.

[0022] Oxygen mixing performance is an important feature that affects the performance of the reformer, and the number and angle of the beveled radial holes will affect the mixing and flow characteristics of the syngas in the furnace. The number and angle of the first-stage oxygen inlet of the reformer need to be designed in detail and accurately according to the pure oxygen flow rate and the diameter of the reformer. The pressure in the furnace is determined by the system pressure, and the system gauge pressure is 0~10MPa.

[0023] Furthermore, the number of primary oxygen inlet holes of the reforming furnace is 2 to 99, and the radial hole opening angle θ ranges from 1 to 75 degrees.

[0024] The beneficial effects of the present invention are as follows: (1) The equipment structure of the present invention is compact, the system operation is simple and easy to implement. The present invention simplifies the process complexity of the reforming system, and heats by directly burning the synthesis gas through a pure oxygen nozzle, has excellent mixed combustion performance, and can obtain a better temperature field. Tar and methane stay in the high temperature zone for a long time, which improves the thermal efficiency in the furnace and reduces the size of the equipment.

[0025] (2) The present invention adopts a multi-stage heat recovery process to generate superheated steam, which can be used in the front-end gasification or pyrolysis system or as a by-product of superheated steam, and has good economy. The low-temperature cooling synthesis gas quenching method is adopted to maximize the use of the sensible heat of the synthesis gas.

[0026] (3) The present invention has excellent economic performance. The multi-stage combustion method is adopted to reduce the core flame temperature of the main combustion zone, increase the high temperature zone through multi-stage combustion, reduce the requirement for high temperature resistance (1800°C) of the equipment, and reduce the equipment investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system principle of the present invention.

[0028] Figure 2 It is a cross-sectional view of the reforming furnace of the present invention.

[0029] Among them: 1- desalted water, 2- tar-containing synthesis gas, 3- pure oxygen, 4- reformer, 5- radiation waste boiler, 6- multi-stage separator, 7- convection waste boiler 1, 8- convection waste boiler 2, 9- filter, 10- scrubber, 11- steam drum, 12- compressor, 13- ash discharge, 14- synthesis gas to shift, 15- superheated steam to users; 41-syngas inlet, 42-oxygen inlet 1, 43-oxygen inlet 2, 44-syngas outlet, 45-slag outlet; 111 - drum water outlet one, 112 - hot water exchange inlet one, 113 - drum water outlet two, 114 - hot water exchange inlet two, 115 - steam outlet, 116 - supplementary desalted water inlet. DETAILED DESCRIPTION

[0030] According to the above invention content, the following embodiments are provided.

[0031] A non-catalytic partial oxidation-reforming reaction decoking method in this embodiment has the following decoking process: the tar-containing synthesis gas 2 and the pure oxygen 3 enter the reforming furnace 4 respectively. The reforming furnace 4 is arranged vertically. The tar-containing synthesis gas 2 and the primary oxygen source (i.e., pure oxygen 3) enter the furnace from the upper end and undergo a pure oxygen combustion reaction at the throat of the reforming furnace 4. After the reaction, the temperature of the synthesis gas located at the upper part of the reforming furnace 4 reaches 1350°C, providing suitable oil pyrolysis temperature conditions; then, when the high-temperature synthesis gas flows through the middle part of the reforming furnace 4, it undergoes a pure oxygen combustion reaction again with the secondary oxygen source entering the reforming furnace 4 to supplement heat and convert the high-temperature synthesis gas The temperature is maintained at about 1350℃; the tar is fully cracked in the furnace; then, the high-temperature synthesis gas flows out from the outlet below the side wall of the reforming furnace 4, and some large particles of ash in the synthesis gas are discharged from the slag discharge port 45 at the bottom of the furnace due to inertia; after the outlet of the radiation waste boiler 5, it is mixed with the quenched synthesis gas, and the ash is separated in the multi-stage separator 6. The gas flows out of the multi-stage separator 6, enters the convection waste boiler 1 7 for heat exchange, enters the convection waste boiler 2 8 for heat exchange, and after flowing out of the convection waste boiler 2 8, the synthesis gas flows into the filter 9, separates the fine dust, and then enters the washing tower 10, and the acid and dust in the synthesis are washed down together through the alkaline washing process. After that, the synthesis gas enters the next stage for separation and transformation 14.

[0032] In the above-mentioned coke removal process, the tar-containing synthesis gas 2 enters the reformer 4 longitudinally from the top, and the primary oxygen source enters the reformer 4 obliquely downward from the throat of the reformer 4, and the oxygen as a whole obliquely wraps the synthesis gas flowing longitudinally, forming a pure oxygen environment wrapped in a circular shape, so that the synthesis gas and the primary oxygen undergo a pure oxygen combustion reaction, and therefore, the temperature of the synthesis gas after the reaction can reach 1350°C in the upper furnace, thereby achieving the cracking of tar in the synthesis gas; when the high-temperature synthesis gas in the upper furnace flows downward and flows through the middle section of the furnace body, the secondary oxygen source enters the furnace obliquely downward from the waist of the reformer, and again obliquely wraps the synthesis gas flowing longitudinally as a whole, and wraps the synthesis gas again, so that the synthesis gas and the secondary oxygen undergo a pure oxygen combustion reaction again, and therefore, the temperature of the synthesis gas can continue to reach 1350°C in the lower furnace, so that the tar is fully cracked.

[0033] like Figure 2As shown, a decoking system suitable for the above-mentioned non-catalytic partial oxidation-reforming reaction decoking method specifically includes: a reforming furnace 4, a radiation waste boiler 5, a multi-stage separator 6, a multi-stage convection waste boiler, a filter 9, a washing tower 10, a steam drum 11, and a compressor 12.

[0034] The top of the reforming furnace 4 is provided with a synthesis gas inlet 41, and the lower side wall of the furnace body of the reforming furnace 4 is provided with a synthesis gas outlet 44, which is connected to the inlet of the radiation waste boiler 5 through a pipeline through the synthesis gas outlet 44, and the heat exchange synthesis gas outlet of the radiation waste boiler 5 is connected to the inlet of the multi-stage separator 6 through a pipeline, and the synthesis gas outlet of the multi-stage separator 6 is connected to the synthesis gas inlet of the multi-stage convection waste boiler, and the synthesis gas outlet of the multi-stage convection waste boiler is connected to the gas inlet of the filter 9 through a pipeline, and the filtered synthesis gas is connected to the synthesis gas conversion 14 through a pipeline.

[0035] The hot water of the radiation waste boiler 5 and the hot water of the multi-stage convection waste boiler are connected to the drum 11 through different pipelines respectively. After the hot water is separated into steam and water in the drum 11, a part of the saturated water flows back to the radiation waste boiler 5 through the pipeline as a heat exchange medium, and the other part of the saturated water and the saturated steam flow into different convection waste boilers of the multi-stage convection waste boiler as heat exchange medium.

[0036] In this embodiment, the throat of the reforming furnace 4 is provided with an oxygen inlet 1 42 , the waist of the reforming furnace 4 is provided with an oxygen inlet 2 43 , and the bottom of the reforming furnace 4 is provided with a slag discharge port 45 .

[0037] Furthermore, the oxygen inlet 1 42 and the oxygen inlet 2 43 are both provided with nozzles inclined downward; the oxygen inlet 1 42 sprays primary oxygen, and the oxygen inlet 2 43 sprays secondary oxygen, both of which are pure oxygen, which enters the furnace through the nozzles to form a pure oxygen environment, wrap the synthesis gas, and are fully mixed with the synthesis gas for combustion.

[0038] Furthermore, the oxygen inlet 1 42 and the oxygen inlet 2 43 are respectively arranged in a ring shape inside the furnace body of the reforming furnace 4 .

[0039] In this embodiment, all the hot water flows into the same steam drum, and then flows out through the steam drum 11 to form corresponding saturated water circulation loops; the steam drum 11 is equipped with a supplementary pipeline of desalted water 1, which is used for the water vapor balance in the steam drum 11; the steam drum 11 has three inlets, specifically: hot water inlet 112, hot water inlet 214, and supplementary desalted water inlet 116.

[0040] In this embodiment, the multi-stage convection waste pot includes a convection waste pot 1 7 and a convection waste pot 2 8 .

[0041] The specific overall process of steam-water heat exchange is: (1) Part of the saturated water in the drum 11 flows out of the drum through the drum water outlet 111, enters the radiation waste boiler 5 through the radiation waste boiler 5 water inlet for heat exchange, flows out of the radiation waste boiler 5 after heat exchange, and flows into the drum through the hot water inlet 112 of the drum 11, thereby forming a saturated steam-water circulation loop.

[0042] (2) Part of the saturated water in the drum 11 flows out of the drum through the drum water outlet 113, enters the convection waste boiler 28 through the water inlet of the convection waste boiler 28 for heat exchange, flows out of the convection waste boiler 28 after heat exchange, and flows into the drum 11 through the hot water inlet 114 of the drum 11, forming another saturated steam-water circulation loop.

[0043] (3) The saturated steam in the drum 11 flows out of the drum 11 through the steam outlet 115, enters the inlet of the convection boiler 7, exchanges heat in the convection boiler 7, and then flows out of the convection boiler 7 to deliver the superheated steam to the user 15, so as to make full use of the superheated steam.

[0044] (4) Supplementation of desalted water 1 into the steam drum 11 The desalted water 1 inlet 116 is used to supplement the desalted water 1 into the steam drum 11 .

[0045] In this embodiment, the synthesis gas after the convection waste boiler 2 heat exchange is divided into two paths, one path enters the filter 9, and the other path is connected to the pipeline at the synthesis gas outlet of the radiation waste boiler 5 through a pipeline arranged with a compressor 12. That is, part of the synthesis gas that has undergone multi-stage convection waste boiler heat exchange is used as quenched synthesis gas and merges with the synthesis gas after radiation heat exchange to enter the next step of filtration.

[0046] In this embodiment, after the large ash particles and the synthesis gas are separated in the multi-stage separator 6, the large ash particles are connected to the ash discharge process through a pipeline through the ash outlet at the bottom of the multi-stage separator 6.

[0047] Oxygen mixing performance is an important feature that affects the performance of the reformer, and the number and angle of the beveled radial holes will affect the mixing and flow characteristics of the syngas in the furnace. The number and angle of the first-stage oxygen inlet of the reformer need to be designed in detail and accurately according to the pure oxygen flow rate and the diameter of the reformer. The pressure in the furnace is determined by the system pressure, and the system gauge pressure is 0~10MPa.

[0048] Furthermore, the number of oxygen inlet 1 42 and oxygen inlet 2 43 of the reforming furnace can be designed to be 2 to 99 according to specific circumstances, and the range of the radial opening angle θ of the inlet is 1 to 75 degrees.

Claims

1. A method for decoking by non-catalytic partial oxidation-reforming reaction, characterized in that: The decoking process is as follows: The tar-containing synthesis gas and oxygen enter the reforming furnace separately. The reforming furnace is arranged vertically. The synthesis gas and the primary oxygen source enter the furnace from the upper end and undergo a pure oxygen combustion reaction at the throat of the reforming furnace. After the reaction, the temperature of the synthesis gas located at the upper part of the reforming furnace reaches at least 1350°C, providing suitable oil pyrolysis temperature conditions; then, when the high-temperature synthesis gas flows through the middle part of the reforming furnace, it undergoes a pure oxygen combustion reaction again with the secondary oxygen source entering the reforming furnace to supplement heat and maintain the temperature of the high-temperature synthesis gas at 1350~1400°C; the tar is fully pyrolyzed in the furnace; then, the high-temperature synthesis gas flows out from the outlet below the side wall of the reforming furnace, and some large particles of ash in the synthesis gas are discharged from the slag discharge port at the bottom of the furnace body due to inertia; The high-temperature synthesis gas after reforming undergoes radiation heat exchange and then ash separation. The synthesis gas after ash separation undergoes multi-stage convection heat exchange in turn. The synthesis gas after heat exchange is subjected to dust separation, and then acid and dust are removed through an alkaline washing process, and finally enters the next stage for separation and transformation.

2. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 1, characterized in that: The synthesis gas enters the reforming furnace longitudinally from the top, and the primary oxygen source enters the furnace obliquely downward from the throat of the reforming furnace. The oxygen as a whole obliquely wraps the synthesis gas flowing longitudinally, forming a pure oxygen environment wrapped in a circular shape, so that the synthesis gas and the primary oxygen undergo a pure oxygen combustion reaction.

3. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 1, characterized in that: The high-temperature synthesis gas in the upper furnace flows downward. When it flows through the middle section of the furnace body, the secondary oxygen source enters the furnace from the waist of the reforming furnace at an angle downward, and again obliquely wraps the synthesis gas flowing longitudinally as a whole, so that the synthesis gas and the secondary oxygen undergo pure oxygen combustion reaction again, making the synthesis gas temperature in the lower furnace continuously reach 1350°C, so that the tar is fully cracked.

4. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 1, characterized in that: The heat exchange water of the radiation heat exchange flows into the steam drum, and then flows out through the steam drum to form a saturated water circulation loop.

5. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 1 or 4, characterized in that: The heat exchange water of the multi-stage convective heat exchange flows into the steam drum through the pipeline, the saturated steam after steam-water separation in the steam drum is uniformly returned to the first-stage convective heat exchange pipeline as heat exchange steam, and the saturated water after steam-water separation in the steam drum is returned to the last-stage convective heat exchange pipeline as heat exchange water, forming a saturated water circulation loop.

6. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 5, characterized in that: The drum is provided with a make-up source of desalinated water.

7. The method for decoking by non-catalytic partial oxidation-reforming reaction according to claim 1, characterized in that: The temperature of the synthesis gas drops to 800℃ after radiation heat exchange.

8. A decoking system suitable for the above-mentioned non-catalytic partial oxidation-reforming reaction decoking method, characterized in that include: Reformer, radiation waste boiler, multi-stage separator, multi-stage convection waste boiler, filter, scrubber, steam drum, compressor; The top of the reforming furnace is provided with a syngas inlet, and the lower side wall of the reforming furnace body is provided with a syngas outlet, which is connected to the inlet of the radiation waste boiler through a pipeline through the syngas outlet, the heat exchange syngas outlet of the radiation waste boiler is connected to the inlet of the multi-stage separator through a pipeline, the syngas outlet of the multi-stage separator is connected to the syngas inlet of the multi-stage convection waste boiler, the syngas outlet of the multi-stage convection waste boiler is connected to the gas inlet of the filter through a pipeline, and the filtered syngas is connected to the syngas conversion process through a pipeline; The hot water of the radiation waste boiler and the hot water of the multi-stage convection waste boiler are connected to the steam drum through different pipelines respectively. After the hot water is separated into steam and water in the steam drum, a part of the saturated water flows back to the radiation waste boiler through the pipeline as a heat exchange medium, and the other part of the saturated water and the saturated steam flow into different convection waste boilers of the multi-stage convection waste boiler as heat exchange medium.

9. The decoking system according to claim 8, characterized in that: The throat of the reforming furnace is provided with oxygen inlet one, the waist of the reforming furnace is provided with oxygen inlet two, and the bottom of the reforming furnace body is provided with a slag discharge port; the number and angle of the oxygen inlets one and two are designed according to the pure oxygen flow rate and the diameter of the reforming furnace.

10. The decoking system according to claim 8, characterized in that: The oxygen inlet 1 and the oxygen inlet 2 are both provided with pure oxygen nozzles inclined downward; oxygen enters the furnace through the nozzles, wraps the synthesis gas, and is fully mixed with the synthesis gas.

11. The decoking system of claim 8, wherein: The oxygen inlet 1 and the oxygen inlet 2 are respectively arranged in a ring shape inside the reforming furnace body.

12. The decoking system of claim 8, wherein: The multi-stage convection waste boiler includes convection waste boiler one and convection waste boiler two. The saturated steam after drum heat exchange is used as the heat exchange medium of convection waste boiler one, and part of the saturated water after drum heat exchange is used as the heat exchange medium of convection waste boiler two.

13. The decoking system of claim 8, wherein: The superheated steam after heat exchange in the convection waste boiler 1 is provided to users through a pipeline, and the synthesis gas after heat exchange enters the convection waste boiler 2; the synthesis gas after heat exchange in the convection waste boiler 2 is divided into two paths, one path enters the filter, and the other path is connected to the pipeline of the radiation waste boiler synthesis gas outlet through a pipeline arranged with a compressor, that is, part of the synthesis gas that has undergone multi-stage convection waste boiler heat exchange is used as quenching synthesis gas and merges with the synthesis gas after radiation heat exchange.

14. The decoking system of claim 8, wherein: The steam drum is also provided with a desalted water supplement pipeline for water vapor balance in the steam drum.

15. The decoking system of claim 8, wherein: The multi-stage separator is provided with an ash outlet at the bottom, which is connected to the ash discharge process through a pipeline.

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