Cracking reaction system and method for preparing low-carbon olefin by taking CO combustion as heat source

Abstract

The invention discloses a cracking reaction system and method for preparing low-carbon olefin by taking CO combustion as a heat source, and belongs to the field of petroleum processing, the cracking reaction system comprises a catalytic combustion device, a CO supply end, an oxygen-containing gas supply end, an adiabatic reactor and a cracking raw material supply end; the CO supply end and the oxygen-containing gas supply end are respectively communicated with the catalytic combustion device; the cracking raw material supply end, the catalytic combustion device and the adiabatic reactor are sequentially communicated. According to the invention, CO catalytic combustion is selectively controlled to provide heat for the cracking reaction, so that the chemical energy of CO is effectively utilized, the demand of fuel gas is reduced, and the emission of harmful CO in waste gas is reduced.

Description

Technical Field

[0001] This invention belongs to the field of petroleum processing and relates to a cracking reaction system and method for preparing low-carbon olefins using CO combustion as a heat source. More specifically, it relates to a system and method for preparing low-carbon olefins, including but not limited to ethylene, propylene and butadiene, by using the heat from CO catalytic combustion to cause thermal cracking of the cracking feedstock. Background Technology

[0002] Catalytic cracking units are crucial secondary processing equipment in the oil refining industry and a key link in the transformation and upgrading of refineries. Based on product type, catalytic cracking units can be divided into catalytic cracking units and catalytic pyrolysis units. Catalytic cracking units primarily produce gasoline, while catalytic pyrolysis units primarily produce liquefied petroleum gas (LPG) (target component is propylene), while also considering gasoline yield. Nationwide, there is a large existing base of catalytic cracking units with high operating rates and load factors. With the rise of the new energy vehicle industry, the fuel market is expected to gradually shrink in the coming years, leading to a gradual increase in the number of retrofitted or newly built catalytic pyrolysis units.

[0003] The ethylene industry is the leading sector of the petrochemical industry, and the ethylene cracking furnace is the main production unit for organic chemical raw materials. The cracking reaction that occurs inside the furnace tubes is a strongly endothermic process, requiring heat primarily provided by the combustion of fossil fuels, thus consuming large amounts of fuel and energy. How to reduce the energy and material consumption of cracking furnaces has always been a key research focus in the cracking field.

[0004] US4812597 and US4914249 employ selective hydrogen combustion catalysts to selectively combust hydrocarbon species such as benzene / styrene in the reaction stream after partial dehydrogenation of ethylbenzene. The energy generated by hydrogen combustion is used to directly heat the stream to raise its temperature to a level where a dehydrogenation reaction can occur, thus reducing energy consumption. Summary of the Invention

[0005] The purpose of this invention is to utilize the energy of CO-rich gas flow in refineries to provide the heat required for steam cracking to produce olefins, thereby reducing the energy required by the cracking reactor and achieving energy conservation and emission reduction.

[0006] This invention proposes a system and method for providing the heat required for the pyrolysis reaction by CO combustion, wherein the CO combustion is carried out in the presence of a selective CO combustion catalyst, which has high selectivity and avoids excessive generation of byproducts.

[0007] The method for preparing low-carbon olefins by hydrocarbon thermal cracking of the present invention includes mixing preheated cracking feedstock, CO-rich gas flow and oxygen-containing gas, and using CO catalytic combustion (CO and O2 are mixed, the reaction is exothermic, and CO2 is generated) to provide energy to raise the system temperature to the temperature required for thermal cracking.

[0008] On one hand, the present invention provides a cracking reaction system for preparing low-carbon olefins using CO combustion as a heat source. The cracking reaction system includes a catalytic combustion device, a CO supply end, an oxygen-containing gas supply end, an adiabatic reactor, and a cracking feedstock supply end. The CO supply end and the oxygen-containing gas supply end are respectively connected to the catalytic combustion device; the cracking feedstock supply end, the catalytic combustion device, and the adiabatic reactor are connected in sequence.

[0009] As a preferred technical solution, the pyrolysis reaction system further includes a preheating furnace, and the pyrolysis feedstock supply end, the preheating furnace, and the catalytic combustion device are connected in sequence.

[0010] Optionally, the catalytic combustion device is a fixed-bed reactor or a fluidized-bed reactor.

[0011] As a preferred technical solution, the connected catalytic combustion device (1) and the adiabatic reactor (4) form a reaction unit; the pyrolysis reaction system includes N reaction units, N = 1 to 10; the first reaction unit, the second reaction unit, ..., the (N-1)th reaction unit and the Nth unit are connected sequentially.

[0012] As a preferred technical solution, the pyrolysis reaction system further includes a cooling device and a separation device; the Nth adiabatic reactor, the cooling device, and the separation device are sequentially connected. The separation device generally includes one or more separation processes selected from compression, distillation, extraction, and cryogenic separation. Appropriate separation processes can be adopted based on the variation range of different raw materials in the low-carbon olefin products.

[0013] On the other hand, the present invention provides a method for carrying out a pyrolysis reaction using any of the above-mentioned pyrolysis reaction systems, comprising the steps of: pyrolysis feedstock provided by the pyrolysis feedstock supply end entering a catalytic combustion device; CO-containing gas material provided by the CO supply end entering the catalytic combustion device; oxygen-containing gas (including but not limited to air, pure oxygen, etc.) provided by the oxygen-containing gas supply end entering the catalytic combustion device; the CO-containing gas contacting the oxygen-containing gas and undergoing a combustion reaction to provide heat for the pyrolysis feedstock; the CO-containing gas stream being combusted in the catalytic combustion device and then discharged from the catalytic combustion device; the pyrolysis feedstock being heated in the catalytic combustion device and then entering an adiabatic reaction device to undergo a pyrolysis reaction to generate pyrolysis gas containing low-carbon olefins.

[0014] As a preferred technical solution, preferably, all the cracked gas (mixed gas) obtained from the first reaction unit enters the catalytic combustion device of the second reaction unit, and the catalytic combustion device of the second reaction unit only introduces oxygen-containing gas, without supplementing the cracked raw materials and flue gas; all the cracked gas (mixed gas) obtained from the second reaction unit enters the catalytic combustion device of the third unit, and the catalytic combustion device of the third reaction unit only introduces oxygen-containing gas, without supplementing the cracked raw materials and flue gas... all the cracked gas (mixed gas) obtained from the (N-1)th reaction unit enters the catalytic combustion device of the Nth reaction unit, and the combustion device of the Nth reaction unit only introduces oxygen-containing gas, without supplementing the cracked raw materials and flue gas, and the Nth reaction unit generates cracked gas containing low-carbon olefins.

[0015] As a preferred technical solution, the pyrolysis feedstock supplied by the pyrolysis feedstock supply end is first preheated in a preheating furnace before entering the catalytic combustion device.

[0016] As a preferred technical solution, the cracked gas containing low-carbon olefins from the adiabatic reaction unit is separated into low-carbon olefin products by a separation device.

[0017] As a preferred technical solution, the cracked gas containing low-carbon olefins from the adiabatic reaction device is first cooled by a cooling device before entering the separation device; preferably, the cooling device cools the cracked gas containing low-carbon olefins to 300-400°C within a time of no more than 0.5 seconds.

[0018] As a preferred technical solution, the diluent is preheated to 200-300°C and then enters the preheating furnace. Preferably, the diluent is water vapor.

[0019] As a preferred technical solution, the pyrolysis feedstock is preheated to 200-300°C in a preheating furnace and then mixed with a diluent; preferably, the weight ratio of the diluent to the pyrolysis feedstock is 0.1-3.0, and more preferably 0.2-2.0.

[0020] As a preferred technical solution, the pyrolysis feedstock is mixed with the diluent, preheated to 500-700°C, and then enters the catalytic combustion device.

[0021] As a preferred technical solution, the CO content in the CO-containing gaseous material is 2wt% to 20wt%, preferably 3wt% to 12wt%.

[0022] As a preferred technical solution, the CO-containing gaseous material supplied by the CO supply end comes from the flue gas of the catalytic cracking unit (flue gas generated by the regenerator). The sources of the CO-containing gaseous material include, but are not limited to, the incompletely regenerated flue gas of the catalytic cracking unit.

[0023] As a preferred technical solution, the total amount of oxygen-containing gas, calculated as pure oxygen, accounts for 10-120% by weight of the pyrolysis feedstock. The molar ratio of oxygen-containing gas to CO, calculated as pure oxygen and pure CO, is 1:1.8 to 1:2.

[0024] Preferably, when the pyrolysis reaction system comprises N reaction units, the oxygen-containing gas is divided into several streams and introduced into the catalytic combustion devices of the first reaction unit, the second reaction unit, and so on, up to the Nth reaction unit. Preferably, the flow rate of each stream decreases sequentially according to the reaction unit.

[0025] Preferably, the pyrolysis reaction system includes three reaction units, with oxygen-containing gas divided into three streams. 60% of the total oxygen-containing gas is fed into the catalytic combustion device of the first reaction unit, 24% of the total oxygen-containing gas is fed into the catalytic combustion device of the second reaction unit, and 16% of the total oxygen-containing gas is fed into the catalytic combustion device of the third reaction unit.

[0026] As a preferred technical solution, the catalytic combustion device is filled with a selective CO combustion catalyst; preferably, the active component of the selective CO combustion catalyst is one or a combination of Pt and Pd, the co-active component is Zr, and the support is one or a combination of cordierite, spherical alumina and SiC.

[0027] The Pt / Al2O3 catalyst of the present invention can be prepared by impregnation method, wherein the Pt content is 0.001-3% by weight, and 0.01-3% by weight of La, Zr, and Ce are added as promoters.

[0028] As a preferred technical solution, the reaction conditions for the combustion reaction include: a temperature of 500℃~750℃, a reaction pressure of 0.1~0.12MPa, and a space velocity of 3.5~4h. -1 .

[0029] The method for calculating air velocity in this invention is as follows: Air velocity (weight) = Total mass flow rate of gas entering the burner / Mass of catalyst in the burner.

[0030] As a preferred technical solution, the cracking feedstock is at least one selected from ethane, propane, liquefied petroleum gas (LPG), topping oil, naphtha, hydrotreated tail oil, and diesel oil; the topping oil contains straight-chain and / or branched-chain hydrocarbons; the naphtha contains straight-chain and / or branched-chain hydrocarbons and / or cycloalkanes.

[0031] As a preferred technical solution, the low-carbon olefins in the cracked gas containing low-carbon olefins are C64-C ... 2-5 Olefin; preferably selected from at least one of ethylene, propylene, and butadiene.

[0032] As a preferred technical solution, the temperature of the CO-containing gaseous material supplied by the CO supply end is higher than 300°C, preferably higher than 500°C, and more preferably higher than 600°C.

[0033] As a preferred technical solution, the conditions for the pyrolysis reaction in the adiabatic reaction device include: a temperature of 700-1000℃, preferably 750-950℃, and more preferably 770-900℃.

[0034] In the refining industry, incomplete regeneration processes such as coal chemical engineering, methane-to-hydrogen production, and catalytic cracking all generate CO-rich streams. The combustion of this CO can produce a significant amount of heat, but this heat is currently not being fully utilized. Introducing the exothermic reaction from CO combustion into ethylene cracking furnaces to replace traditional fuels (such as natural gas and CH4) can significantly reduce the use of traditional fuels, thereby reducing energy consumption.

[0035] The beneficial effects of this invention are:

[0036] 1. In the method of the present invention, by selectively controlling the catalytic combustion of CO to provide heat for the cracking reaction, the chemical energy of CO is effectively utilized, and the demand for fuel gas is reduced;

[0037] 2. In the method of the present invention, the emission of harmful CO in the exhaust gas is reduced by selectively controlling the catalytic combustion of CO. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the pyrolysis reaction system for preparing low-carbon olefins using CO combustion as a heat source according to the present invention.

[0039] In the diagram, 1 is the catalytic combustion device, 2 is the CO supply end, 3 is the preheating furnace, 4 is the adiabatic reactor, and 5 is the separation device. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments, but these do not constitute any limitation on the invention. All raw materials used in the embodiments are commercially available.

[0041] The pyrolysis reaction method includes the following steps:

[0042] (1) Preheat the pyrolysis feedstock to 200-300℃ and preheat the diluent to 200-300℃;

[0043] (2) After the preheated pyrolysis feedstock is mixed with the preheated diluent, it is heated to 500-700°C in a preheating furnace to obtain the mixed pyrolysis feedstock;

[0044] (3) Mix the mixed pyrolysis feedstock, CO-containing gaseous material (e.g., flue gas) with oxygen-containing gas (including but not limited to air, pure oxygen, and the O2 content in the oxygen-containing gas is in the range of 21-100%), introduce it into a catalytic combustion device, catalyze the combustion reaction of CO and O2, and heat the mixture to 700-1000°C.

[0045] (4) The mixture from (3) enters the adiabatic reaction device, where a thermal cracking reaction occurs to generate cracked gas containing low-carbon olefins, and the temperature drops to 500-750°C.

[0046] (5) The cracked gas from (4) enters the reaction unit consisting of one catalytic combustion device and one adiabatic reaction device, and repeats steps (3) and (4) N times, where N takes the value of 0 to 10;

[0047] (6) The material from the Nth adiabatic reaction device recovers heat through a cooling device (preferably a quenching device) and cools the material to 300-400°C;

[0048] (7) The cracked gas containing low-carbon olefins from the cooling unit is separated by a separation system to obtain low-carbon olefin products including ethylene, propylene and butadiene.

[0049] This invention makes full use of the CO-rich flue gas generated by the regenerator in the catalytic cracking unit of the refinery, saving fuel gas consumption and achieving the effect of energy saving and emission reduction.

[0050] The Pt / Al2O3 catalysts of Examples 2 and 3 of this invention were prepared by impregnation method:

[0051] 0.75g chloroplatinic acid, 50g alumina balls, and 1.55g lanthanum nitrate were impregnated in equal volumes and dried at 120℃ for 2h; calcined at 500℃ for 4h; and then reduced with H2 at 450℃ for 6h.

[0052] The composition of the flue gas (640-690℃) in Examples 2 and 3 of this invention is shown in Table 1.

[0053] Table 1. Components of regenerator flue gas

[0054] Components Kgmol / h M％ Kg / h W％ CO 754.864 5.78％ 21136 5.63％ <![CDATA[CO2]]> 1509.7 11.56％ 66428 17.70％ <![CDATA[O2]]> 11.6 0.09％ 371 0.10％ <![CDATA[N2]]> 9266.8 70.95％ 259469 69.15％ <![CDATA[SO2]]> 10.4 0.08％ 666 0.18％ <![CDATA[H2O]]> 1507.7 11.54％ 27140 7.23％ total 13061.1 100.00％ 375210 100.00％

[0055] Example 1: Pyrolysis Reaction System

[0056] The pyrolysis reaction system consists of a catalytic combustion device 1 (fixed bed reactor or fluidized bed reactor), a CO supply end 2, a preheating furnace 3, an oxygen-containing gas supply end, an adiabatic reactor 4, and a separation device 5. The CO supply end 2 and the oxygen-containing gas supply end are respectively connected to the catalytic combustion device (1). The CO-containing gaseous material is mixed with O2 and undergoes a catalytic combustion reaction in the catalytic combustion device 1. The pyrolysis feedstock preheating furnace 3, the catalytic combustion device 1, the adiabatic reactor 4, and the separation device 5 are connected in sequence.

[0057] Example 2: Pyrolysis Reaction Method

[0058] Taking a catalytic cracking unit with a capacity of 3 million tons / year as an example, a mixture of ethane and propane is introduced as the cracking feedstock. The conditions for the mixed feedstock are 40℃, 0.7MPa, and a flow rate of 9341kg / hr.

[0059] The pyrolysis reaction method includes the following steps:

[0060] (1) The pyrolysis feedstock is first preheated in preheating furnace 3 (flue gas can be introduced into the preheating furnace to preheat the pyrolysis feedstock), and the temperature is raised to 250°C.

[0061] (2) Diluting steam (at 250°C, 1.0 MPa, and a flow rate of 2289 kg / hr) is injected into preheating furnace 3 to obtain a mixture. After steam injection, the flow rate increases to 11630 kg / hr. The mixture is preheated to 680°C in preheating furnace 3.

[0062] (3) The flue gas (components detailed in Table 1) generated by the regenerator in the catalytic cracking unit and the preheated mixture to 680°C are respectively fed into the catalytic combustion unit 1 and mixed with air at a rate of 53376 kg / hr. The catalytic combustion unit 1 (fixed-bed reactor or fluidized-bed reactor) is filled with Pt / Al2O3 catalyst, the reaction pressure is 0.1 MPa, the reaction temperature is 680°C, and the space velocity is 4 h⁻¹. -1 In catalytic combustion unit 1, the heat generated by the catalytic combustion of CO heats the mixture to 860°C;

[0063] (4) The mixture heated to 860°C enters the adiabatic reactor 4 and undergoes a cracking reaction to obtain cracked gas rich in low-carbon olefins (see Table 2 for the composition).

[0064] (5) The cracked gas enters the separation unit 5 and is separated to obtain products such as ethylene, propylene and butadiene.

[0065] Table 2. Composition of gaseous streams rich in low-carbon olefins.

[0066] CO 0.02％ <![CDATA[CH4]]> 10.96％ <![CDATA[C2H4]]> 29.96％ <![CDATA[C2H6]]> 13.57％ <![CDATA[C3H6]]> 8.90％ <![CDATA[C3H8]]> 7.35％ <![CDATA[C4H6]]> 1.58％ <![CDATA[C4H8]]> 0.40％ <![CDATA[C4H 10 ]]> 0.06％ other 27.20％ total 100.00％

[0067] Example 3: Pyrolysis Reaction Method

[0068] Taking a catalytic cracking unit with a capacity of 3 million tons / year as an example, a mixture of ethane and propane is introduced as the cracking feedstock. The conditions for the mixed feedstock are 40℃, 0.7MPa, and a flow rate of 9341kg / hr.

[0069] The pyrolysis reaction method includes the following steps:

[0070] (1) The pyrolysis feedstock is first preheated in preheating furnace 3 (flue gas can be introduced into the preheating furnace to preheat the pyrolysis feedstock), and the temperature is raised to 250°C.

[0071] (2) Diluting steam (at 250°C, 1.0 MPa, and a flow rate of 2289 kg / hr) is injected into preheating furnace 3 to obtain a mixture. After steam injection, the flow rate increases to 11630 kg / hr. The mixture is preheated to 680°C in preheating furnace 3.

[0072] (3) The preheated mixture to 680℃ and the flue gas generated by the regenerator in the catalytic cracking unit (components detailed in Table 1) enter the first catalytic combustion unit and are mixed with air at a flow rate of 32025 kg / hr to obtain mixed gas I-1. The first catalytic combustion unit is filled with Pt / Al2O3 catalyst, the reaction temperature is 680℃, the reaction pressure is 0.1 MPa, and the space velocity is 4 h⁻¹. -1 In catalytic combustion device 1, the heat generated by the catalytic combustion of CO heats the mixed gas I-1 to 850°C;

[0073] (4) The mixed gas I-1 heated to 850°C enters the first adiabatic reactor and undergoes a cracking reaction (850°C) to obtain a mixed gas I-2 rich in low-carbon olefins that is cooled to 730°C (see Table 3 for the composition).

[0074] (5) Mixed gas I-2 enters the second catalytic combustion device and mixes with air at a flow rate of 12810.2 kg / hr to obtain mixed gas II-1. The second catalytic combustion device is filled with Pt / Al2O3 catalyst, the reaction pressure is 0.1 MPa, the reaction temperature is 730℃, and the space velocity is 4 h⁻¹. -1 In the second catalytic combustion device, the heat generated by the catalytic combustion of CO in mixed gas II-1 heats mixed gas II-1 to 840°C.

[0075] (6) The mixed gas II-1 heated to 840°C enters the second adiabatic reactor and undergoes a cracking reaction to obtain mixed gas II-2 rich in low-carbon olefins, which is cooled to 740°C (see Table 3 for composition details).

[0076] (7) Mixed gas II-2 enters the third catalytic combustion unit and mixes with air at a flow rate of 8540.2 kg / hr to obtain mixed gas III-1. The catalytic combustion unit is filled with Pt / Al2O3 catalyst, the reaction pressure is 0.1 MPa, the reaction temperature is 740℃, and the space velocity is 4 h⁻¹. -1 In the third catalytic combustion unit, the heat generated by the catalytic combustion of CO heats the mixed gas III-1 to 830°C.

[0077] (8) Mixed gas III-1 heated to 830°C enters the third adiabatic reactor and undergoes a cracking reaction to obtain cracked gas rich in low-carbon olefins, which is cooled to 730°C (see Table 3 for composition details).

[0078] (9) The cracked gas enters the separation unit 5 and is separated to obtain products such as ethylene, propylene and butadiene.

[0079] Table 3. Composition of gaseous streams rich in low-carbon olefins.

[0080]

[0081] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88… and 69-71 and 70-71, etc. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0082] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A pyrolysis reaction system, characterized in that, The pyrolysis reaction system includes a catalytic combustion device (1), a CO supply end (2), an oxygen-containing gas supply end, an adiabatic reactor (4), and a pyrolysis feedstock supply end; The CO supply end (2) and the oxygen-containing gas supply end are respectively connected to the catalytic combustion device (1); The pyrolysis feedstock supply end, the catalytic combustion device (1), and the adiabatic reactor (4) are connected in sequence.

2. The pyrolysis reaction system according to claim 1, characterized in that, The cracking reaction system also includes a preheating furnace (3), and the cracking raw material supply end, the preheating furnace (3), and the catalytic combustion device (1) are connected in sequence; And / or, the catalytic combustion device (1) is a fixed-bed reactor or a fluidized-bed reactor.

3. The pyrolysis reaction system according to claim 1 or 2, characterized in that, The connected catalytic combustion device (1) and the adiabatic reactor (4) form a reaction unit; The pyrolysis reaction system comprises N reaction units, where N = 1 to 10; The first reaction unit, the second reaction unit, ..., the (N-1)th reaction unit and the Nth unit are connected sequentially; And / or, the pyrolysis reaction system further includes a cooling device and a separation device (5); The Nth adiabatic reactor (4), cooling device, and separation device (5) are connected in sequence.

4. A method for carrying out a pyrolysis reaction using the pyrolysis reaction system according to any one of claims 1-3, characterized in that, Including the following steps: The cracking feedstock supplied by the cracking feedstock supply end enters the catalytic combustion device (1); the CO-containing gaseous material supplied by the CO supply end (2) enters the catalytic combustion device (1); the oxygen-containing gas supplied by the oxygen-containing gas supply end enters the catalytic combustion device (1); the CO-containing gas and the oxygen-containing gas come into contact and undergo a combustion reaction; After being heated in the catalytic combustion device (1), the cracking feedstock enters the adiabatic reaction device (4) to undergo a cracking reaction and generate cracked gas containing low-carbon olefins.

5. The method for pyrolysis reaction according to claim 4, characterized in that, The pyrolysis feedstock supplied by the pyrolysis feedstock supply end is first preheated by the preheating furnace (3) and then enters the catalytic combustion device (1); And / or, the cracked gas containing low-carbon olefins from the adiabatic reaction unit (4) is separated by the separation unit (5) to obtain low-carbon olefin products.

6. The method for the pyrolysis reaction according to claim 4 or 5, characterized in that, The cracked gas containing low-carbon olefins from the adiabatic reaction unit (4) is first cooled by a cooling device and then enters the separation unit (5). The cooling device cools the cracked gas containing low-carbon olefins to 300-400°C within 0.5 seconds.

7. The method for the pyrolysis reaction according to any one of claims 4-6, characterized in that, The diluent is first preheated to 200-300°C and then enters the preheating furnace (3). Preferably, the diluent is water vapor. And / or, the pyrolysis feedstock is preheated to 200-300°C in a preheating furnace (3) and then mixed with a diluent; preferably, the weight ratio of the diluent to the pyrolysis feedstock is 0.1-3.0, more preferably 0.2-2.0; And / or, the pyrolysis feedstock is mixed with a diluent, preheated to 500-700°C, and then enters the catalytic combustion device (1).

8. The method for the pyrolysis reaction according to any one of claims 4-7, characterized in that, The CO-containing gaseous material has a CO content of 2 wt% to 20 wt%, preferably 3 wt% to 12 wt%. And / or, the CO-containing gaseous material supplied by the CO supply end comes from the flue gas of the catalytic cracking unit; And / or, based on pure oxygen, the amount of oxygen-containing gas accounts for 10 to 120% by weight of the pyrolysis feedstock; And / or, based on pure oxygen and pure CO, the molar ratio of oxygen-containing gas to CO is 1:1.8 to 1:2; The catalytic combustion device (1) is filled with a selective CO combustion catalyst; preferably, the active component of the selective CO combustion catalyst is one or a combination of Pt and Pd, the co-active component is Zr, and the support is one or a combination of cordierite, spherical alumina and SiC. The combustion reaction conditions include: reaction pressure of 0.1 MPa to 0.12 MPa, temperature of 500℃ to 750℃, and space velocity of 4 h⁻¹. -1 .

9. The method for the pyrolysis reaction according to any one of claims 4-8, characterized in that, The pyrolysis feedstock is at least one of ethane, propane, liquefied petroleum gas, topping oil, naphtha, hydrotreated tail oil, and diesel oil. The head-pulling oil contains straight-chain and / or branched-chain hydrocarbons; The naphtha contains straight-chain and / or branched-chain hydrocarbons and / or cycloalkanes; The low-carbon olefins in the cracked gas containing low-carbon olefins are C64-C ... 2-5 Olefin; preferably selected from at least one of ethylene, propylene, and butadiene.

10. The method for the pyrolysis reaction according to any one of claims 4-9, characterized in that, The temperature of the CO-containing gaseous material supplied by the CO supply end is higher than 300°C, preferably higher than 500°C, and more preferably higher than 600°C. The conditions for the pyrolysis reaction in the adiabatic reaction device (4) include: a temperature of 700-1000℃, preferably 750-950℃, and more preferably 770-900℃.

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