Pyrolysis oil gas reforming reaction furnace

Abstract

The utility model discloses a pyrolysis oil gas reforming reaction furnace which comprises an upper sealing head, a vertical furnace body and a lower sealing head which are connected in sequence, the upper sealing head is connected with a pyrolysis gaseous product connecting pipe, the lower sealing head is connected with a slag falling pipe, and the lower part of the vertical furnace body is connected with an exhaust pipe. Refractory linings are arranged in the upper sealing head, the pyrolysis gaseous product connecting pipe, the vertical furnace body, the exhaust pipe, the lower sealing head and the slag falling pipe, and the slag falling pipe is provided with a valve; a first-stage gasifying agent nozzle connecting pipe, a second-stage gasifying agent nozzle connecting pipe and a third-stage gasifying agent nozzle connecting pipe are sequentially arranged on the side wall of the vertical furnace body from top to bottom; the device has the advantages of sufficient heat and mass transfer in the furnace, good uniformity of a temperature field in the furnace and complete reaction, and can improve the quality of outlet synthesis gas.

Description

Technical Field

[0001] The utility model relates to a reforming reactor, in particular to a reforming reactor used for pyrolyzing oil and gas. Background Art

[0002] Low-temperature, oxygen-free pyrolysis of organic solid waste involves the slow thermal decomposition (also known as cracking or dry distillation) of organic solid waste at 350-500°C while strictly limiting oxygen concentration to produce gaseous pyrolysis products—pyrolysis oil (tar), pyrolysis gas (non-condensable gas), water vapor, and a solid pyrolysis residue. This process allows for the resource-based, high-value utilization of organic solid waste. Low-temperature, oxygen-free pyrolysis of organic solid wastes, such as agricultural and forestry biomass, waste plastics, waste rubber, and waste textiles, produces high-calorific-value gaseous pyrolysis products at 350-500°C. These gaseous pyrolysis products can be further autothermally reformed with steam and oxygen in a reforming reactor to produce synthesis gas primarily composed of hydrogen and carbon monoxide, which can then be used in the industrial production of high-purity hydrogen, synthetic ammonia, and methanol.

[0003] The pyrolysis gaseous products contain hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), alkanes below C4, alkanes above C4, and benzene ring hydrocarbons. Not only are the components complex, but the steam oxygen autothermal reforming reaction at 1200~1400℃ is also relatively complex.

[0004] Existing reactors, such as patent CN102923658B, disclose a non-catalytic partial oxidation reformer for gaseous hydrocarbons. This reformer targets gaseous hydrocarbons, primarily methane, such as natural gas, shale gas, coalbed methane, oilfield gas, refinery gas, coke oven gas, and pyrolysis gas. It features high conversion efficiency, a long service life for the refractory lining, and convenient load adjustment. However, in the actual production process, there are still the following problems in achieving the direct preparation of synthesis gas from high calorific value pyrolysis gaseous products at 350~500℃: (1) Low-temperature oxygen-free pyrolysis furnaces are usually tubular or rotary kiln types. Due to the limitations of sealing technology, the outlet pressure of their pyrolysis gaseous products usually does not exceed 200Pa(g). It is difficult to use nozzles and burners to increase the flow rate of pyrolysis gaseous products while fully mixing them with the gasifying agent (a higher flow rate can ensure that the heat load in the furnace is not concentrated). This results in poor mixing of gaseous products with gasifying agents such as steam and oxygen in the furnace, which in turn leads to problems such as insufficient heat and mass transfer, concentrated heat load in the furnace, incomplete reaction, and high tar content in the outlet synthesis gas; (2) The gaseous products in the reforming reactor are in a process of rapid temperature increase and rapid flow increase. In order to ensure the residence time, the diameter of the furnace is larger than the diameter of the gaseous product inlet pipe. The position of the gasifying agent nozzle connecting pipe on the reactor cannot achieve efficient heat and mass transfer in the furnace, resulting in incomplete autothermal reforming reaction and high tar content in the outlet synthesis gas.

[0005] Patent CN110964572B discloses a gasifying agent channel assembly consisting of oxygen and steam nozzles for a pulverized coal gasifier. Four such assemblies are evenly spaced on the same horizontal cross-section of the upper portion of the gasifier body, expected to achieve an "oxygen-in-water" tangential circular effect. However, for pyrolysis gaseous products with relatively slow flow rates (less than 20 m / s), separating the gasification channel into oxygen and steam nozzles is unnecessary. This results in difficulty in mixing the gasifying agents and between the gasifying agents and the pyrolysis gaseous products. Furthermore, single-stage introduction of the gasifying agent can lead to concentrated heat loads within the furnace and incomplete reactions, reducing the quality of the outlet syngas. Summary of the Invention

[0006] The purpose of this utility model is to provide a pyrolysis oil and gas reforming reactor to address the above-mentioned deficiencies in the prior art, which has the advantages of sufficient heat and mass transfer in the furnace, good uniformity of the temperature field in the furnace, and complete reaction, and can improve the quality of the exported synthesis gas.

[0007] In order to achieve the above-mentioned purpose, the utility model provides a pyrolysis oil and gas reforming reactor, comprising an upper head, a vertical furnace body and a lower head connected in sequence, the upper head is connected to a pyrolysis gas product connecting pipe, the lower head is connected to a slag dropping pipe, the lower part of the vertical furnace body is connected to an exhaust pipe, the upper head, the pyrolysis gas product connecting pipe, the vertical furnace body, the exhaust pipe, the lower head and the slag dropping pipe are all provided with a refractory lining, and the slag dropping pipe is provided with a valve; it is characterized in that: a first-stage gasifying agent nozzle connecting pipe, a second-stage gasifying agent nozzle connecting pipe and a third-stage gasifying agent nozzle connecting pipe are provided in sequence from top to bottom on the side wall of the vertical furnace body; the first-stage gasifying agent nozzle connecting pipe includes a circumferentially evenly distributed and There are 3 to 8 first-level connecting pipes located at the same height, and the center lines of the first-level connecting pipes all intersect with the central axis of the vertical furnace body; the second-level gasifier nozzle connecting pipe includes 4 to 12 second-level connecting pipes that are evenly distributed on the circumference in the same rotation direction and located at the same height, and the center lines of all the second-level connecting pipes form a tangential circle with a diameter of d1 around the central axis of the vertical furnace body and the center of the circle coincides with the central axis of the vertical furnace body; the third-level gasifier nozzle connecting pipe includes 3 to 8 tertiary connecting pipes that are evenly distributed on the circumference and located at the same height, and the center lines of the tertiary connecting pipes all intersect with the central axis of the vertical furnace body; the third-level gasifier nozzle connecting pipe is located above the exhaust pipe.

[0008] During use, the pyrolysis oil and gas are introduced into the furnace body through the pyrolysis gaseous product connecting pipe. The gasifying agent containing more than 90% oxygen and saturated steam is divided into three levels and introduced into the furnace body in a graded manner to react with the pyrolysis oil and gas. Among them, the second-level gasifying agent has the highest oxygen content and is injected in a tangentially circular manner with a momentum 3 to 15 times that of the pyrolysis oil and gas. It fully entrains, disturbs and mixes the pyrolysis oil and gas, and has the advantages of sufficient heat and mass transfer in the furnace, good temperature field uniformity in the furnace, and complete reaction, which can improve the quality of the exported synthesis gas.

[0009] As a further improvement of the present invention, the ratio of the tangential circle diameter d1 to the flow inner diameter d0 of the pyrolysis gas product connecting pipe is d1:d0=1.3~0.9; this can improve the entrainment, disturbance and mixing effect of the second-stage gasifying agent on the pyrolysis oil and gas;

[0010] As a further improvement of the present invention, the ratio of the centerline height difference H0 between the first-stage gasifying agent nozzle connecting pipe and the exhaust pipe to the flow inner diameter D0 of the furnace is H0:D0=4-2; so that the reaction maintains a reasonable residence time in the furnace, which is conducive to the occurrence of autothermal oxidation reaction and sufficient preheating of pyrolysis oil and gas;

[0011] As a further improvement of the present invention, the ratio of the centerline height difference H1 to H0 between the third-stage gasifying agent nozzle connecting pipe and the exhaust pipe is H1:H0=0.4~0.5, and the ratio of the centerline height difference H2 to H0 between the second-stage gasifying agent nozzle connecting pipe and the first-stage gasifying agent nozzle connecting pipe is H2:H0=0.2~0.3; so that the temperature field at the effective reaction height in the furnace is uniform, which is conducive to complete reaction;

[0012] As a further improvement of the present invention, the exhaust pipe is located in the tangential direction of the vertical furnace body and is consistent with the direction of the airflow ejected from the second-stage gasifying agent nozzle connecting pipe; on the one hand, it is beneficial to the discharge of the outlet synthesis gas, and on the other hand, it is beneficial to maintain the entrainment, disturbance and mixing effects in the furnace;

[0013] In summary, the utility model has the advantages of sufficient heat and mass transfer in the furnace, good uniformity of the temperature field in the furnace, and complete reaction, and can improve the quality of the exported synthesis gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the front view of the embodiment of the present utility model.

[0015] Figure 2 for Figure 1 AA cross-sectional view.

[0016] Figure 3 for Figure 1 BB cross-sectional view.

[0017] Figure 4 for Figure 1 CC cross-sectional view. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] like Figures 1 to 4As shown, a pyrolysis oil and gas reforming reactor of this embodiment includes an upper head 1, a vertical furnace body 2 and a lower head 3 connected in sequence. The upper head 1 is connected to a pyrolysis gas product connecting pipe 4, the lower head 3 is connected to a slag dropping pipe 5, and the lower part of the vertical furnace body 2 is connected to an exhaust pipe 6. The upper head 1, the pyrolysis gas product connecting pipe 4, the vertical furnace body 2, the exhaust pipe 6, the lower head 3 and the slag dropping pipe 5 are all provided with a refractory lining 7, and the slag dropping pipe 5 is provided with a valve (not shown); the first level is provided in sequence from top to bottom on the side wall of the vertical furnace body 2. The gasifier nozzle connecting pipe 8, the second-stage gasifier nozzle connecting pipe 9 and the third-stage gasifier nozzle connecting pipe 10; the first-stage gasifier nozzle connecting pipe 8 includes three first-stage connecting pipes evenly distributed on the circumference and located at the same height, and the center lines of the first-stage connecting pipes all intersect with the central axis of the vertical furnace body 2; the second-stage gasifier nozzle connecting pipe 9 includes four second-stage connecting pipes evenly distributed on the circumference in the same rotation direction and located at the same height, and the center lines of all the second-stage connecting pipes form a diameter d around the central axis of the vertical furnace body 2. 1 and the center of the circle coincides with the central axis of the vertical furnace body, the ratio of the diameter of the tangential circle d1 to the flow inner diameter d0 of the pyrolysis gas product connecting pipe 4 is d1:d0=1.3~0.9; the third-stage gasifying agent nozzle connecting pipe 10 includes three third-stage connecting pipes evenly distributed on the circumference and located at the same height, and the center lines of the three-stage connecting pipes all intersect with the central axis of the vertical furnace body 2; the third-stage gasifying agent nozzle connecting pipe 10 is located above the exhaust pipe 6, and the exhaust pipe 6 is located in the tangential direction of the vertical furnace body 2 and is connected to the second-stage gasifying agent nozzle. The airflow ejected from the gasifier nozzle connecting pipe 9 is in the same direction; the ratio of the centerline height difference H0 between the first-stage gasifying agent nozzle connecting pipe 8 and the exhaust pipe 6 to the flow inner diameter D0 of the furnace is H0:D0=4~2; the ratio of the centerline height difference H1 between the third-stage gasifying agent nozzle connecting pipe 10 and the exhaust pipe 6 to H0 is H1:H0=0.4~0.5, and the ratio of the centerline height difference H2 between the second-stage gasifying agent nozzle connecting pipe 9 and the first-stage gasifying agent nozzle connecting pipe 8 to H0 is H2:H0=0.2~0.3.

[0020] During operation, the pyrolysis oil and gas and each level of gasifying agent are introduced at positive pressure, with the exhaust pipe 6 connected to a negative pressure device such as an induced draft fan. The pyrolysis oil and gas, at an inlet pressure of 50 Pa(g) and a temperature of 400-500°C, are introduced into the furnace body 2 via the pyrolysis gaseous product connection pipe 2. The gasifying agent, containing at least 90% oxygen and saturated steam, has a temperature of approximately 180°C. The gasifying agent is divided into three levels and introduced into the furnace body in a graded manner to react with the pyrolysis oil and gas. The first-level gasifying agent, comprising 15-25% of the total oxygen demand, is introduced via the first-stage gasifying agent nozzle connection pipe 8. This is intended to preheat the pyrolysis oil and gas at 400-500°C through oxidation (combustion heat release), creating conditions for the reforming reaction while also avoiding heat load concentration in the furnace area near the second-stage gasifying agent nozzle connection pipe 9.

[0021] The second-stage gasifying agent is introduced through the second-stage gasifying agent nozzle connecting pipe 9, accounting for 75-80% of the total oxygen demand, and is injected in a tangentially circular manner with a momentum 3-15 times that of the pyrolysis oil and gas, fully entraining, disturbing and mixing the pyrolysis oil and gas. This has the advantages of sufficient heat and mass transfer in the furnace, good temperature field uniformity in the furnace, and complete reaction, which can improve the quality of the exported synthesis gas. When the momentum is insufficient, it is also necessary to consider adding saturated steam.

[0022] The third-stage gasifying agent is introduced through the third-stage gasifying agent nozzle connecting pipe 10, accounting for 0% to 5% of the total oxygen demand. The purpose is to maintain the temperature range in the reforming reactor and promote the complete reaction of methane in the synthesis gas as much as possible. In the event of overheating at the reactor outlet, the third-stage gasifying agent can be switched to saturated steam for temporary temperature adjustment and auxiliary means of emergency temperature control.

[0023] By setting the ratio of the tangential circle diameter d1 to the flow inner diameter d0 of the pyrolysis gas product connecting pipe to 1.3-0.9, the entrainment, disturbance and mixing effects of the second-stage gasifying agent on the pyrolysis oil and gas can be further improved;

[0024] By setting H0∶D0=4~2, the reaction can maintain a reasonable residence time in the furnace, which is conducive to the occurrence of autothermal oxidation reaction and sufficient preheating of pyrolysis oil and gas;

[0025] By setting H1:H0=0.4~0.5, H2:H0=0.2~0.3, the temperature field at the effective reaction height in the furnace is more uniform, which is conducive to complete reaction;

[0026] The exhaust pipe 6 is located in the tangential direction of the vertical furnace body 2, which is conducive to the discharge of the outlet synthesis gas and also helps to maintain the entrainment, disturbance and mixing effects in the furnace;

[0027] The present invention is not limited to the above-mentioned embodiments, for example, the number of the first-stage gasifying agent nozzle connecting pipe 8, the second-stage gasifying agent nozzle connecting pipe 9 and the third-stage gasifying agent nozzle connecting pipe 10 can be adjusted according to the size of the furnace body;

[0028] The above embodiments have been used for illustration, but it should be understood that the above embodiments are only used for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments.

Claims

1. A pyrolysis oil and gas reforming reactor, comprising an upper head, a vertical furnace body, and a lower head connected in sequence, wherein the upper head is connected to a pyrolysis gas product connecting pipe, the lower head is connected to a slag drop pipe, and the lower portion of the vertical furnace body is connected to an exhaust pipe. The upper head, the pyrolysis gas product connecting pipe, the vertical furnace body, the exhaust pipe, the lower head, and the slag drop pipe are all provided with a refractory lining, and the slag drop pipe is provided with a valve; the characteristics are: A first-stage gasifier nozzle connecting pipe, a second-stage gasifier nozzle connecting pipe and a third-stage gasifier nozzle connecting pipe are sequentially provided on the side wall of the vertical furnace body from top to bottom; the first-stage gasifier nozzle connecting pipe includes 3 to 8 first-stage connecting pipes evenly distributed on the circumference and located at the same height, and the center lines of the first-stage connecting pipes all intersect with the central axis of the vertical furnace body; the second-stage gasifier nozzle connecting pipe includes 4 to 12 second-stage connecting pipes evenly distributed on the circumference in the same rotation direction and located at the same height, and the center lines of all second-stage connecting pipes form a tangential circle with a diameter of d1 around the central axis of the vertical furnace body and the center of the circle coincides with the central axis of the vertical furnace body; the third-stage gasifier nozzle connecting pipe includes 3 to 8 third-stage connecting pipes evenly distributed on the circumference and located at the same height, and the center lines of the third-stage connecting pipes all intersect with the central axis of the vertical furnace body; the third-stage gasifier nozzle connecting pipe is located above the exhaust pipe.

2. The pyrolysis oil and gas reforming reactor according to claim 1, characterized in that: The ratio of the tangential circle diameter d1 to the flow inner diameter d0 of the pyrolysis gas product connecting pipe is d1:d0=1.3~0.

9.

3. A pyrolysis oil and gas reforming reactor according to claim 1 or 2, characterized in that: The ratio of the centerline height difference H0 between the first-stage gasifying agent nozzle connecting pipe and the exhaust pipe to the flow inner diameter D0 of the furnace is H0:D0=4~2.

4. The pyrolysis oil and gas reforming reactor according to claim 3, characterized in that: The ratio of the centerline height difference H1 to H0 between the third-stage gasifying agent nozzle connecting pipe and the exhaust pipe is H1:H0=0.4~0.5, and the ratio of the centerline height difference H2 to H0 between the second-stage gasifying agent nozzle connecting pipe and the first-stage gasifying agent nozzle connecting pipe is H2:H0=0.2~0.

3.

5. The pyrolysis oil and gas reforming reactor according to claim 4, characterized in that: The exhaust pipe is located in the tangential direction of the vertical furnace body and is consistent with the direction of the airflow ejected from the second-stage gasifying agent nozzle connecting pipe.

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