A reactor and method for producing low carbon olefins by direct heating of hydrocarbons by a heat carrier

Abstract

The present application relates to a kind of reactor and method for preparing low carbon olefin by hydrocarbon pyrolysis of heat carrier direct heating, the reactor includes combustion zone, mixed pre-reaction zone located downstream of combustion zone, main reaction zone located downstream of mixed pre-reaction zone and quenching zone located downstream of main reaction zone.The method is implemented based on the above-mentioned reactor, including the following steps: S1: hydrogen, and the mixture of water vapor and oxygen are respectively simultaneously introduced into hydrogen-oxygen burner, and the high-temperature water vapor generated by hydrogen combustion enters the combustion zone cylinder;S2: high-temperature water vapor flows through shrinkage cone body and equal-diameter short section in turn, mixes with raw materials from first raw material inlet and second raw material inlet, and part of raw materials are cracked, then the material enters the enlarged cone body, mixes with raw materials from third raw material inlet and reacts, and the reaction product enters the quenching zone cooling, to obtain the target product.Compared with prior art, the reactor and method of the present application have the characteristics of wide raw material application range and high selectivity of target product.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of olefin production equipment, and relates to a reactor and a method for directly heating hydrocarbons by a heat carrier to prepare low-carbon olefins. BACKGROUND

[0002] Ethylene cracking furnace is an important equipment unit in the petrochemical industry, and more than 90% of ethylene in the world is produced by ethylene cracking furnaces. The existing ethylene cracking furnace is composed of a radiation chamber, a convection chamber, a quenching boiler, a burner and the like. The burner is installed in the radiation chamber, and fuel is combusted through the burner to generate a large amount of high-temperature flue gas. The radiation furnace tube is suspended in the radiation chamber, and the high-temperature flue gas transmits heat to the radiation furnace tube in the radiation chamber through radiation heat transfer, heats the medium in the tube, and makes the raw material crack to generate low-carbon olefins. In this process, the high-temperature flue gas heat is transferred from the outside of the tube to the medium in the tube, and the high-temperature flue gas and the material in the tube are not in direct contact, which is called indirect heat transfer. The heat transfer intensity of this process is limited by the maximum use temperature of the radiation furnace tube material. The radiation furnace tube is used at a high temperature for a long time, and its service life is generally only 5-6 years. The heat rate of the cracking furnace is generally only 92-94%. Since the raw material needs to be preheated and vaporized in the convection section heat transfer tube, the use of what raw material as a cracking raw material is limited. This traditional cracking method usually uses ethane, propane, liquefied gas, naphtha, diesel oil and hydrogenated tail oil as cracking raw materials. The cracking raw materials with higher end boiling point, larger specific gravity and higher aromatic content, or untreated condensate oil and crude oil are not suitable for direct use as cracking raw materials of the existing cracking furnace.

[0003] In order to eliminate the shortcomings of the above-mentioned traditional cracking furnace and expand the source range of cracking raw materials, technical personnel have made a lot of research on the direct heating of hydrocarbons by a heat carrier since the 1970s. In recent years, technical personnel have also made some exploratory research on the method for directly cracking crude oil to produce olefins.

[0004] The direct heating of hydrocarbons by a heat carrier refers to that the high-temperature heat carrier is directly mixed with the cracking raw material, and the heat carrier directly transmits heat to the cracking raw material through direct contact with the cracking raw material. The cracking raw material reaches the cracking reaction temperature and cracks.

[0005] CN 101875591A discloses a method for producing low-carbon olefins by cracking hydrocarbons. The method is to introduce preheated hydrocarbon raw materials, hydrogen and oxygen-containing gas into several units containing hydrogen catalytic combustion device and adiabatic reaction device; in the hydrogen catalytic combustion device, hydrogen is burned to provide energy to raise the temperature of the mixture to the required temperature for cracking reaction; in the adiabatic reaction device, thermal cracking reaction occurs to generate a stream containing low-carbon olefins; finally, after recovering heat through a quenching device, various low-carbon olefin products are obtained through a separation system. This technology uses a selective hydrogen combustion catalyst, and the mixture of hydrogen, oxygen and cracking raw materials is introduced into the hydrogen catalyst device to make the hydrogen in the mixture catalytically combust, thereby providing heat for the cracking reaction.

[0006] US3161695 discloses a process for producing alkyne, the reactor is a circular tube, the circular tube wall has certain heat conduction performance, the outside of the circular tube is an annular high-temperature-resistant material, and there is a certain gap between the annular high-temperature-resistant material and the outer wall of the circular tube reactor, which is a combustion chamber. Hydrogen and oxygen are combusted in the combustion chamber, then flow upward along the combustion chamber, and then mix with the raw materials entering from the top end of the circular tube reactor, and then enter the circular reaction tube to occur cracking reaction. The wall of the circular reactor has certain heat conduction performance, which can supplement a certain amount of heat for the cracking reaction.

[0007] WO 2004 / 005431 A1, US7578929B2 and other published direct cracking technologies of crude oil are characterized by using crude oil as cracking raw material, but have certain requirements for the properties of the crude oil, and need to cut off the heavy end components in the crude oil during processing, and only the part suitable for cracking raw material is sent into the traditional tubular steam cracking furnace for cracking. This method to some extent expands the source of cracking raw materials.

[0008] In summary, the existing technologies generally have the problems of narrow raw material adaptation range, long reaction residence time, short running cycle, low thermal efficiency, large amount of greenhouse gas emission, and some need catalysts. SUMMARY

[0009] The present application aims to provide a reactor and a method for directly heating a hydrocarbon pyrolysis to produce low-carbon olefins by using a heat carrier, so as to overcome the defects of the prior art, such as narrow raw material adaptation range, long reaction residence time, short operation cycle, low thermal efficiency, large greenhouse gas emission, and the need for a catalyst. In view of the deficiencies of the prior art, the present application provides a reactor and a method for directly heating a hydrocarbon pyrolysis to produce low-carbon olefins by using a heat carrier. The method is based on the reactor and uses hydrogen-oxygen combustion to generate high-temperature steam, which is directly contacted with the pyrolysis raw material to rapidly transfer heat to the pyrolysis raw material, so as to produce low-carbon olefins through thermal cracking. The reactor and the method have a wide raw material adaptation range, high thermal efficiency, and no greenhouse gas emission, can meet the conditions required by the pyrolysis reaction, such as high temperature, short residence time, and low hydrocarbon partial pressure, and can significantly improve the selectivity of the target olefins and prolong the operation cycle of the reactor.

[0010] The object of the present application can be achieved by the following technical solutions:

[0011] One of the technical solutions of the present application provides a reactor for directly heating a hydrocarbon pyrolysis to produce low-carbon olefins by using a heat carrier, which comprises:

[0012] a combustion zone for providing high-temperature steam, which comprises a combustion zone cylinder with one end closed, the combustion zone cylinder being provided with a hydrogen-oxygen burner;

[0013] a mixing pre-reaction zone downstream of the combustion zone for mixing the raw material and the high-temperature steam, which comprises a converging cone and an equal-diameter short section, the flared end of the converging cone being connected to the open end of the combustion zone cylinder, the narrow end of the converging cone being connected to one end of the equal-diameter short section, the converging cone being provided with a first raw material inlet, and the equal-diameter short section being provided with a second raw material inlet;

[0014] a main reaction zone downstream of the mixing pre-reaction zone, which comprises an expanding cone, the narrow end of the expanding cone being connected to the other end of the equal-diameter short section, and the expanding cone being provided with a third raw material inlet;

[0015] a quenching zone downstream of the main reaction zone for stopping the pyrolysis reaction.

[0016] Further, the hydrogen-oxygen burner is provided with a plurality of hydrogen-oxygen burners, which are arranged at equal intervals around the central axis of the combustion zone cylinder on the side wall of the combustion zone cylinder or at the central part of the closed end of the combustion zone cylinder.

[0017] Further, when the oxyhydrogen burner is arranged at the side wall of the combustion zone cylinder, the angle between the center line of the flame jetted by the oxyhydrogen burner and the tangent of the circumference of the side wall of the combustion zone cylinder is 0-180°.

[0018] Further, when the oxyhydrogen burner is arranged at the center of the closed end of the combustion zone cylinder, the center line of the flame jetted by the oxyhydrogen burner is parallel to the central axis of the combustion zone cylinder.

[0019] Further, when several oxyhydrogen burners are arranged at the side wall of the combustion zone cylinder, the several oxyhydrogen burners are arranged in multiple layers.

[0020] Further, the inner wall of the combustion zone cylinder is further provided with a high-temperature-resistant heat insulation material layer.

[0021] Further, the high-temperature-resistant heat insulation material layer is one or a combination of high-temperature-resistant fiber layer, high-temperature-resistant brick layer, and high-temperature-resistant castable layer.

[0022] Further, the combustion zone cylinder is a double-jacket structure, and a cooling medium is circulated in the jacket.

[0023] Further, the cooling medium is water, liquid hydrocarbon, methanol, or silicone oil.

[0024] Further, the first raw material inlet is provided with several first raw material inlets, and the several first raw material inlets are arranged at the side wall of the converging cone body at equal intervals around the central axis of the converging cone body.

[0025] Further, the several first raw material inlets are arranged in multiple layers, and each layer is provided with 2-4 first raw material inlets.

[0026] Further, the first raw material inlet is arranged vertically at the side wall of the converging cone body.

[0027] Further, the second raw material inlet is provided with several second raw material inlets, and the several second raw material inlets are arranged at the side wall of the constant-diameter nipple at equal intervals around the central axis of the constant-diameter nipple.

[0028] Further, the several second raw material inlets are arranged in multiple layers, and each layer is provided with 2-4 second raw material inlets.

[0029] Further, the angle between the central axis of the second raw material inlet and the side wall of the constant-diameter nipple is 10-170°.

[0030] Further, the third raw material inlet is provided with several third raw material inlets, and the several third raw material inlets are arranged at the side wall of the expanding cone body at equal intervals around the central axis of the expanding cone body.

[0031] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0032] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0033] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0034] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0035] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0036] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0037] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0038] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0039] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0040] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0041] Further, the third raw material inlets are arranged in multiple layers, each layer having 2-4 third raw material inlets.

[0042] S1: Start the hydrogen-oxygen burner, and simultaneously introduce hydrogen and oxygen into the hydrogen-oxygen burner, and hydrogen is burned to generate high-temperature steam entering the combustion zone cylinder.

[0043] S2: The obtained high-temperature steam sequentially flows through the converging cone and the constant-diameter nipple, and is mixed with the cracking raw materials from the first raw material inlet and the second raw material inlet, and part of the cracking raw materials undergoes a cracking reaction, and then the materials enter the expanding cone, are mixed with the cracking raw materials from the third raw material inlet, and further react, and the reaction products enter the quenching zone for cooling to obtain the target product.

[0044] Further, in step S1, water vapor is also introduced while oxygen is introduced, and the volume ratio of oxygen to water vapor is 1:(0-10) and is not 1:0. In the hydrogen-oxygen burner, hydrogen is introduced into the central passage of the hydrogen-oxygen burner, and the mixture of oxygen and water vapor is introduced into the sleeve outside the central passage.

[0045] Further, in step S1, the temperature of the high-temperature water vapor at the outlet of the combustion zone cylinder is 1000-1500°C, and can be 1200-1400°C. In the present application, the temperature of the high-temperature water vapor at the outlet of the combustion zone cylinder is adjusted to 1000-1500°C by adjusting the ratio of the introduced oxygen to water vapor.

[0046] Further, in step S2, the cracking raw material is one or more of ethane, propane, n-butane, liquefied petroleum gas (LPG), C5, naphtha, diesel, hydrogenated tail oil, condensate oil, residual oil or crude oil.

[0047] Further, in step S2, while the cracking raw material is introduced, atomizing water vapor (or protective water vapor) is also introduced at the first raw material inlet, the second raw material inlet and the third raw material inlet, and the mass ratio of the atomizing water vapor to the cracking raw material is (0.1-5):1. The atomizing water vapor normally refers to the water vapor that atomizes the cracking raw material, but when it is just started, the combustion zone cylinder already has high-temperature water vapor generated by hydrogen-oxygen combustion, and the water vapor is introduced first to protect the nozzle before the cracking raw material enters, and therefore it is also called protective water vapor.

[0048] Further, in step S2, the residence time of the material in the expanding cone is 0.01-0.5s, and can be 0.05-0.15s, and the temperature of the reaction product at the outlet of the main reaction zone is 600-900°C. Since the cracking reaction occurs in the expanding cone, a large amount of small-molecule products are generated, and the number of moles of the reaction product increases greatly. The purpose of using the expanding cone is to ensure that the mixture has a high flow rate and a small frictional resistance drop at this location. The residence time of the material in the expanding cone is determined by the internal volume of the expanding cone and the flow rate of the material at this location.

[0049] Further, in step S2, the flow rate of the material at the equal-diameter short section is 50-200m / s, and can be 80-120m / s. In the original design, according to the properties of the raw material, the raw material flow rate, the water vapor flow rate, the temperature and pressure at this location and other parameters, the volume of the equal-diameter short section is calculated to ensure that the flow rate is in the range of 50-200m / s.

[0050] Further, in step S2, when the reaction product enters the quenching zone, the reaction product is cooled by directly spraying a cooling medium or by using indirect heat exchange.

[0051] Further, in step S2, the reaction product is cooled by the quenching zone, and the temperature of the reaction product is 300-600°C.

[0052] Further, in step S2, the reaction product is cooled by the quenching zone, and then enters a secondary cooling zone, and the reaction product is further cooled to 180-250°C by the cooling medium sprayed into the secondary cooling zone.

[0053] In step S2, the cracking raw material is injected into the converging conical body of the mixing pre-reaction zone, and the high-temperature water vapor directly transmits heat to the cracking raw material, and part of the hydrocarbons in the cracking raw material reaches the cracking reaction temperature to form a mixture composed of water vapor, cracking raw material and reaction product, and the temperature of the mixture is 1000-1100°C. Then, the mixture enters the constant-diameter short section of the mixing pre-reaction zone, and the cracking raw material is further injected into the second raw material inlet of the constant-diameter short section to further strengthen the mixing, heat transfer and partial cracking reaction of the material.

[0054] In step S2, the material enters the main reaction zone, and the cracking raw material is continuously injected into the third raw material inlet of the expanding conical body. With the progress of the cracking reaction, the number of small molecules increases, and the molar number of the mixture rapidly increases. The equilibrium temperature of the mixture after passing through the expanding conical body is 600-900°C, and the pressure is 0.05-2.5 MPaG.

[0055] In step S2, the reaction product enters the quenching zone for cooling. Different cooling methods can be selected according to different cracking raw materials. When the cracking raw material is relatively light, the indirect heat exchange method can be used to recover the waste heat of the reaction mixture. When the raw material is relatively heavy, the direct spraying of the cooling medium can be used to first cool the reaction mixture, and then the waste heat is recovered. The temperature of the reaction mixture after heat recovery in the quenching zone is 300-600°C, and the temperature can be selected as 350-450°C. In the field, the weight of the raw material is usually determined by the specific gravity of the raw material. Generally, ethane, propane, LPG and naphtha are relatively light raw materials, and diesel oil, hydrogenated tail oil and crude oil are relatively heavy raw materials. In the present application, the specific gravity of 0.8 is used as the dividing line. The raw material with a specific gravity lower than 0.8 can be called light, and the raw material with a specific gravity higher than 0.8 can be called heavy.

[0056] In step S2, the reaction mixture after heat recovery in the quenching zone enters the secondary cooling zone. The key equipment in the secondary cooling zone is the quenching device. The cooling medium is sprayed into the quenching device, and the cooling medium can be water or hydrocarbon. After the cooling medium is sprayed, the reaction mixture is cooled to 180-250°C. The cooled reaction mixture enters the subsequent separation system for further low-temperature heat recovery and component separation.

[0057] When the material leaves the enlarged cone of the main reaction zone, its temperature is still as high as about 800℃, and the material will undergo a large amount of secondary reactions in this state for a long time. The so-called secondary reactions refer to the further dehydrogenation and polycondensation of unstable molecules such as olefins and diolefins, which will reduce the target olefins. Therefore, the purpose of setting the quenching zone at the outlet of the main reaction zone is to rapidly cool the reaction products. It is generally believed that the secondary reactions can be terminated when the temperature is cooled to below 600-650℃.

[0058] Compared with the prior art, the present application has the following advantages:

[0059] (1) The present application uses the high-temperature steam generated by hydrogen-oxygen combustion to directly mix with the cracking raw material, so that the raw material reaches the required temperature for cracking reaction in a very short time, and the reaction residence time is shortened by more than 50% compared with the prior art. The high-temperature steam generated by hydrogen-oxygen combustion also plays a role in reducing the partial pressure of hydrocarbons, thereby improving the selectivity of the target product.

[0060] (2) The present application uses a direct heating method to produce low-carbon olefins, which has high thermal efficiency and will not cause coking in the heat exchange tube. The adaptability of the raw material is more extensive, and the operation cycle of the reactor is longer.

[0061] (3) The present application uses the high-temperature steam generated by hydrogen-oxygen combustion as a direct heating carrier, which does not emit greenhouse gases and other pollutants.

[0062] (4) The present application does not need to use a catalyst to produce low-carbon olefins. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 It is a structural schematic diagram of the reactor of Example 1-3 (direct cooling).

[0064] Figure 2 It is a structural schematic diagram of the reactor of Example 4 (indirect heat exchange).

[0065] Figure 3 It is a process flow diagram of the direct heating of hydrocarbons by the heat carrier to produce low-carbon olefins in Example 2-3.

[0066] Figure 4 It is a process flow diagram of the direct heating of hydrocarbons by the heat carrier to produce low-carbon olefins in Example 4.

[0067] Figure 5 It is a schematic diagram of the parallel use of 5 reactors in Example 5.

[0068] Figure 6 It is a schematic diagram of the movement of the mixture of hydrogen, steam and oxygen in the hydrogen-oxygen burner.

[0069] MARK DESCRIPTION IN THE FIGURE:

[0070] 1-Combustion zone, 1-1-Hydrogen-oxygen burner, 1-2-High-temperature resistant brick layer, 1-3-Combustion zone cylinder, 2-Mixing pre-reaction zone, 2-1-Converging cone, 2-2-Constant diameter short section, 2-3-First raw material inlet, 2-4-Second raw material inlet, 3-Primary reaction zone, 3-1-Diverging cone, 3-2-Third raw material inlet, 3-3-Primary reaction zone outlet, 4-Quenching zone, 4-1-Quenching zone inlet, 4-2-Quenching zone outlet, 4-3-Direct cooling medium inlet, 4-4-Indirect cooling medium inlet, 4-5-Indirect cooling medium outlet, 4-6-Indirect heat exchanger, 4-7-Heat exchange cylinder, 5-Secondary cooling zone. DETAILED DESCRIPTION

[0071] The application will be described in detail below with reference to the drawings and specific embodiments. The embodiments are implemented on the premise of the technical scheme of the application, and detailed implementation and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0072] In the following embodiments or examples, if no specific description is given for the function components or structures, it is indicated that they are all conventional components or conventional structures adopted in the field to realize the corresponding functions.

[0073] In the description of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0074] In the description of the application, unless otherwise specified, the terms "first", "second", "third" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0075] In order to overcome the defects of the prior art, such as narrow raw material adaptation range, long reaction residence time, short running cycle, low thermal efficiency, large greenhouse gas emission or the need for catalyst, the application provides a reactor and method for directly heating hydrocarbon cracking to produce low-carbon olefins by heat carrier.

[0076] One of the technical schemes of the application provides a reactor for directly heating hydrocarbon cracking to produce low-carbon olefins by heat carrier, as shown in Figures 1-2 The reactor comprises:

[0077] A combustion zone 1 for providing high-temperature water vapor: it comprises a combustion zone cylinder 1-3 with one end closed, which is provided with a hydrogen-oxygen burner 1-1;

[0078] a mixing pre-reaction zone 2 for mixing raw materials and high-temperature water vapor downstream of the combustion zone 1, which comprises a converging cone 2-1 and an equal-diameter short section 2-2, the flared end of the converging cone 2-1 being connected to the unsealed end of the combustion zone cylinder 1-3, the narrow end of the converging cone 2-1 being connected to one end of the equal-diameter short section 2-2, the converging cone 2-1 being provided with a first raw material inlet 2-3, and the equal-diameter short section 2-2 being provided with a second raw material inlet 2-4;

[0079] a main reaction zone 3 downstream of the mixing pre-reaction zone 2, which comprises an expanding cone 3-1, the narrow end of the expanding cone 3-1 being connected to the other end of the equal-diameter short section 2-2, and the expanding cone 3-1 being provided with a third raw material inlet 3-2;

[0080] a quenching zone 4 downstream of the main reaction zone 3 for stopping the cracking reaction.

[0081] In some specific embodiments, the hydrogen-oxygen burner 1-1 is provided with several hydrogen-oxygen burners 1-1, which are arranged at equal intervals around the central axis of the combustion zone cylinder 1-3 on the side wall of the combustion zone cylinder 1-3 or at the central part of the sealed end of the combustion zone cylinder 1-3.

[0082] In more specific embodiments, please refer to Figures 1-2 , several hydrogen-oxygen burners 1-1 are arranged at equal intervals around the central axis of the combustion zone cylinder 1-3 on the side wall of the combustion zone cylinder 1-3, and the central part of the sealed end of the combustion zone cylinder 1-3 is also provided with the hydrogen-oxygen burner 1-1.

[0083] In more specific embodiments, the hydrogen-oxygen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 has a central line of the flame jetting out at an angle of 0-180° with the tangent of the circumference of the side wall of the combustion zone cylinder 1-3 when in operation, and the hydrogen-oxygen burner 1-1 arranged at the central part of the sealed end of the combustion zone cylinder 1-3 has a central line of the flame jetting out parallel to the central axis of the combustion zone cylinder 1-3 when in operation.

[0084] In more specific embodiments, when several hydrogen-oxygen burners 1-1 are arranged on the side wall of the combustion zone cylinder 1-3, the several hydrogen-oxygen burners 1-1 are arranged in multiple layers.

[0085] In some specific embodiments, the inner wall of the combustion zone cylinder 1-3 is provided with a high-temperature-resistant thermal insulation material layer.

[0086] In more specific embodiments, the high-temperature-resistant thermal insulation material layer is one or a combination of a high-temperature-resistant fiber layer, a high-temperature-resistant brick layer 1-2, or a high-temperature-resistant castable layer.

[0087] In more specific embodiments, referring to Figure 1 The inner wall of the combustion zone cylinder 1-3 is provided with a high-temperature-resistant brick layer 1-2.

[0088] In some specific embodiments, the combustion zone cylinder 1-3 is a double-jacket structure, and a cooling medium is circulated in the jacket.

[0089] In more specific embodiments, the cooling medium is water, liquid hydrocarbon, methanol, or silicone oil.

[0090] In some specific embodiments, referring to Figure 1 The first raw material inlet 2-3 is provided with a plurality of first raw material inlets 2-3, which are arranged equidistantly around the central axis of the converging conical body 2-1 on the side wall of the converging conical body 2-1.

[0091] In more specific embodiments, the plurality of first raw material inlets 2-3 are arranged in multiple layers, and each layer is provided with 2-4 first raw material inlets 2-3.

[0092] In more specific embodiments, the first raw material inlet 2-3 is arranged vertically on the side wall of the converging conical body 2-1.

[0093] In some specific embodiments, referring to Figure 1 The second raw material inlet 2-4 is provided with a plurality of second raw material inlets 2-4, which are arranged equidistantly around the central axis of the constant-diameter section 2-2 on the side wall of the constant-diameter section 2-2.

[0094] In more specific embodiments, the plurality of second raw material inlets 2-4 are arranged in multiple layers, and each layer is provided with 2-4 second raw material inlets 2-4.

[0095] In more specific embodiments, the central axis of the second raw material inlet 2-4 forms an angle of 10-170° with the side wall of the constant-diameter section 2-2.

[0096] In some specific embodiments, referring to Figure 1 The third raw material inlet 3-2 is provided with a plurality of third raw material inlets 3-2, which are arranged equidistantly around the central axis of the expanding conical body 3-1 on the side wall of the expanding conical body 3-1.

[0097] In more specific embodiments, the plurality of third raw material inlets 3-2 are arranged in multiple layers, and each layer is provided with 2-4 third raw material inlets 3-2.

[0098] In more specific embodiments, the central axis of the third raw material inlet 3-2 forms an angle of 10-170° with the side wall of the expanding conical body 3-1. In more specific embodiments, the central axis of the third raw material inlet 3-2 forms an angle of 10-170° with the side wall of the expanding conical body 3-1.

[0099] In some specific embodiments, the angle between the side wall of the constant-diameter nipple 2-2 and the side wall of the expanding cone 3-1 is 100-170°, optionally 115-135°.

[0100] In some specific embodiments, the angle between the side wall of the converging cone 2-1 and the side wall of the combustion zone cylinder 1-3 is 100-170°, optionally 120-150°.

[0101] In some specific embodiments, referring to Figure 1 or Figure 2 the quenching zone 4 comprises a heat exchange cylinder 4-7, one end of the heat exchange cylinder 4-7 being connected to the flared end of the expanding cone 3-1.

[0102] In more specific embodiments, referring to Figure 1 the heat exchange cylinder 4-7 is provided with a direct cooling medium inlet 4-3.

[0103] In more specific embodiments, referring to Figure 2 the heat exchange cylinder 4-7 is provided with an indirect heat exchanger 4-6.

[0104] In some specific embodiments, referring to Figure 1 the downstream of the quenching zone 4 is further provided with a secondary cooling zone 5 for further cooling of the pyrolysis products.

[0105] In more specific embodiments, the secondary cooling zone 5 is provided with a quencher, through which the cooling medium is sprayed to cool the pyrolysis products.

[0106] The second technical solution of the present application provides a method for directly heating hydrocarbon pyrolysis with a heat carrier to produce low-carbon olefins, which is implemented by using the above reactor, comprising the following steps:

[0107] S1: Turn on the oxyhydrogen burner 1-1, and simultaneously introduce a mixture of hydrogen, water vapor and oxygen into the oxyhydrogen burner 1-1, respectively, hydrogen is burned, and the generated high-temperature water vapor enters the combustion zone cylinder 1-3;

[0108] S2: The obtained high-temperature water vapor flows through the converging cone 2-1 and the constant-diameter nipple 2-2 in sequence, mixes with the pyrolysis raw materials from the first raw material inlet 2-3 and the second raw material inlet 2-4 in sequence, part of the pyrolysis raw materials undergoes a pyrolysis reaction, and then the material enters the expanding cone 3-1, mixes with the pyrolysis raw materials from the third raw material inlet 3-2 and further reacts, and the reaction products enter the quenching zone 4 for cooling, and the target product is obtained.

[0109] In some specific embodiments, in step S1, the hydrogen is introduced into the central passage of the oxyhydrogen burner 1-1, and the mixture of oxygen and water vapor is introduced into the sleeve outside the central passage.

[0110] In some specific embodiments, in step S1, the water vapor is introduced at the same time as the oxygen, and the volume ratio of the mixture of oxygen and water vapor is 1:(0-10) and not 1:0.

[0111] In some specific embodiments, in step S1, the temperature of the high-temperature water vapor at the outlet of the combustion zone cylinder 1-3 is 1000-1500℃, and can be 1200-1400℃. The present application adjusts the ratio of the introduced oxygen and water vapor to adjust the temperature of the high-temperature water vapor at the outlet of the combustion zone cylinder 1-3 to be 1000-1500℃.

[0112] In some specific embodiments, in step S2, the cracking raw material is one or more of ethane, propane, n-butane, liquefied petroleum gas (LPG), carbon five, naphtha, diesel, hydrogenated tail oil, condensate oil, residual oil, or crude oil.

[0113] In some specific embodiments, in step S2, the first raw material inlet 2-3, the second raw material inlet 2-4, and the third raw material inlet 3-2 introduce the cracking raw material at the same time as the atomizing water vapor (or protective water vapor), and the mass ratio of the atomizing water vapor to the cracking raw material is (0.1-5):1.

[0114] In some specific embodiments, in step S2, the residence time of the material in the expanding cone 3-1 is 0.01-0.5s, and can be 0.05-0.15s, and the temperature of the reaction product at the outlet of the main reaction zone 3-3 is 600-900℃.

[0115] In some specific embodiments, in step S2, the flow rate of the material at the constant-diameter short section 2-2 is 50-200m / s, and can be 80-120m / s.

[0116] In some specific embodiments, in step S2, when the reaction product enters the quenching zone 4, the reaction product is cooled by directly spraying a cooling medium or using indirect heat exchange.

[0117] In some specific embodiments, in step S2, after the reaction product is cooled by the quenching zone 4, the temperature of the reaction product is 300-600℃.

[0118] In some specific embodiments, the reaction product after being cooled by the quenching zone 4 in step S2, further enters a secondary cooling zone 5, and the cooling medium sprayed into the secondary cooling zone 5 further cools the reaction product to 180-250℃.

[0119] In the following embodiments, the hydrogen-oxygen burner 1-1, when in operation, simultaneously introduces a mixture of hydrogen, water vapor and oxygen into the hydrogen-oxygen burner 1-1, and the flow path of the mixture in the hydrogen-oxygen burner 1-1 is shown in the following schematic diagram: Figure 6 In the hydrogen-oxygen burner 1-1, the hydrogen is introduced into the central passage of the hydrogen-oxygen burner 1-1, and the mixture of oxygen and water vapor is introduced into the sleeve outside the central passage.

[0120] Embodiment 1:

[0121] The present embodiment provides a reactor for directly heating a heat carrier to pyrolyze hydrocarbons and produce low-carbon olefins, as shown in the following schematic diagram: Figure 1 The reactor includes a combustion zone 1, a hydrogen-oxygen burner 1-1, a high-temperature-resistant brick layer 1-2, a combustion zone cylinder 1-3, a mixing pre-reaction zone 2, a converging cone 2-1, an equal-diameter short section 2-2, a first raw material inlet 2-3, a second raw material inlet 2-4, a main reaction zone 3, an expanding cone 3-1, a third raw material inlet 3-2, a main reaction zone outlet 3-3, a quenching zone 4, a quenching zone inlet 4-1, a quenching zone outlet 4-2, a direct cooling medium inlet 4-3, a heat exchange cylinder 4-7, and a secondary cooling zone 5.

[0122] The combustion zone 1 includes a combustion zone cylinder 1-3 with one end closed; the mixing pre-reaction zone 2 is located downstream of the combustion zone 1, and includes the converging cone 2-1 and the equal-diameter short section 2-2, the flared end of the converging cone 2-1 is connected to the open end of the combustion zone cylinder 1-3, and the narrow end of the converging cone 2-1 is connected to one end of the equal-diameter short section 2-2; the main reaction zone 3 is located downstream of the mixing pre-reaction zone 2, and includes the expanding cone 3-1, the narrow end of the expanding cone 3-1 is connected to the other end of the equal-diameter short section 2-2; the quenching zone 4 is located downstream of the main reaction zone 3, and includes the heat exchange cylinder 4-7, one end of the heat exchange cylinder 4-7 is connected to the flared end of the expanding cone 3-1, and the heat exchange cylinder 4-7 is provided with the direct cooling medium inlet 4-3; the secondary cooling zone 5 is located downstream of the quenching zone 4, and the quenching zone outlet 4-2 is connected to the secondary cooling zone 5, the secondary cooling zone 5 is provided with a quenching device, and the cooling medium can be sprayed into the quenching device to cool the pyrolysis product from the quenching zone 4.

[0123] Five hydrogen-oxygen burners 1-1 are provided, one of which is arranged at the center of the closed end of the combustion zone cylinder 1-3, and the other four are arranged at the side wall of the combustion zone cylinder 1-3 at equal intervals around the central axis of the combustion zone cylinder 1-3. The angle between the central line of the flame jet by the hydrogen-oxygen burner 1-1 arranged at the side wall of the combustion zone cylinder 1-3 and the tangent of the circumference of the side wall of the combustion zone cylinder 1-3 is 120°. The central line of the flame jet by the hydrogen-oxygen burner 1-1 arranged at the center of the closed end of the combustion zone cylinder 1-3 is parallel to the central axis of the combustion zone cylinder 1-3.

[0124] The inner wall of the combustion zone cylinder 1-3 is provided with a high-temperature-resistant brick layer 1-2.

[0125] Four first raw material inlets 2-3 are provided, which are arranged at equal intervals around the central axis of the converging conical body 2-1 at the side wall of the converging conical body 2-1. The first raw material inlets 2-3 are arranged vertically at the side wall of the converging conical body 2-1.

[0126] Four second raw material inlets 2-4 are provided, which are arranged at equal intervals around the central axis of the constant-diameter short section 2-2 at the side wall of the constant-diameter short section 2-2. The angle between the central axis of the second raw material inlet 2-4 and the side wall of the constant-diameter short section 2-2 is 90°.

[0127] Four third raw material inlets 3-2 are provided, which are arranged at equal intervals around the central axis of the expanding conical body 3-1 at the side wall of the expanding conical body 3-1. The angle between the central axis of the third raw material inlet 3-2 and the side wall of the expanding conical body 3-1 is 90°.

[0128] The angle between the side wall of the constant-diameter short section 2-2 and the side wall of the expanding conical body 3-1 is 150°. The angle between the side wall of the converging conical body 2-1 and the side wall of the combustion zone cylinder 1-3 is 120°.

[0129] The quenching zone 4 of the present embodiment is a direct quenching type. As shown in FIG. 1, the quenching zone inlet 4-1 is connected to the main reaction zone outlet 3-3, and a direct cooling medium is sprayed through the direct cooling medium inlet 4-3. The direct cooling medium inlet 4-3 is arranged at equal intervals around the central axis of the heat exchange cylinder 4-7, and the cooling medium is quenching oil. The quenching oil is mixed with the reaction mixture, and then enters the secondary cooling zone 5 for further cooling. Figure 1

[0130] Example 2:

[0131] A single reactor for producing 100,000 tons of ethylene per year:

[0132] In the present embodiment, the reactor of Example 1 is used to directly heat and crack condensate oil to produce low-carbon olefins. The specifications of the condensate oil are shown in Table 1:​

[0133] Table 1 Specifications of the condensate oil of Example 2

[0134] Item Data Density (20°C) / (kg / m3) 3 )]]> 789.7 Kinematic viscosity (40°C) / (mm 2 / s) 2.299 Sulfur content / % 0.0143 Pour point / °C 19 Carbon residue / % 0.05 Flash point / °C Flaming at room temperature Characteristic factor K 12.76 Carbon content / % 83.18 Hydrogen content / % 14.85

[0135] The step of directly heating and cracking the condensate oil to produce low carbon olefins is as follows:

[0136] S1: Turn on the oxyhydrogen burner 1-1, and simultaneously introduce a mixture of hydrogen and water vapor and oxygen into the oxyhydrogen burner 1-1, respectively, and the hydrogen is burned, and the generated high-temperature water vapor enters the combustion zone cylinder 1-3.

[0137] S2: The obtained high-temperature water vapor successively flows through the converging cone body 2-1 and the constant-diameter short section 2-2, and successively mixes with the cracking raw materials from the first raw material inlet 2-3 and the second raw material inlet 2-4, part of the cracking raw materials undergoes a cracking reaction, and then the material enters the expanding cone body 3-1, mixes with the cracking raw materials from the third raw material inlet 3-2 and further reacts, and the reaction product enters the quenching zone 4, and is sprayed into 180°C quenching oil through the direct cooling medium inlet 4-3, the cracking gas is fully mixed with the quenching oil in the quenching zone 4, the quenching oil cools the high-temperature cracking gas to 350°C, and the cracking reaction is terminated to obtain the target product, and the target product enters the secondary cooling zone 5 for further cooling. The temperature of the mixture at the outlet 4-2 of the quenching zone is controlled by controlling the amount of quenching oil sprayed.

[0138] In step S1, the hydrogen flow rate is 2220 kg / hr, the oxygen flow rate is 15996 kg / hr, and the water vapor flow rate is 59040 kg / hr.

[0139] In step S2, the first raw material inlet 2-3, the second raw material inlet 2-4 and the third raw material inlet 3-2 are simultaneously introduced with atomizing water vapor while introducing the cracking raw materials, and the mass ratio of the atomizing water vapor to the cracking raw materials is 0.2:1. The residence time of the material in the expanding cone body 3-1 is 0.05 s, and the flow rate of the material at the constant-diameter short section 2-2 is 80 m / s.

[0140] As Figure 3As shown, the hydrogen flow rate is 2220 kg / hr, the oxygen flow rate is 15996 kg / hr, and the water vapor flow rate is 59040 kg / hr. The mixture of oxygen and water vapor enters the hydrogen-oxygen burner 1-1, mixes with hydrogen in the hydrogen-oxygen burner 1-1, and burns to generate high-temperature water vapor with a temperature of 1300°C. The condensate oil is injected into the mixing pre-reaction zone 2, and the condensate oil flow rate is 36800 kg / hr. The condensate oil mixes with the high-temperature water vapor, and the high-temperature water vapor directly transfers heat to the condensate oil. The condensate oil rapidly increases in temperature to 830-860°C and rapidly undergoes cracking reaction to produce cracking gas. The cracking gas temperature at the outlet of the main reaction zone 3-3 is about 800°C. The quenching oil is injected into the quenching zone 4 to cool the cracking gas to 350°C. Then, the mixture enters the subsequent system for further separation.

[0141] Table 2 Comparison of product distribution of direct heating cracking of condensate oil and traditional tube furnace steam cracking in Example 2

[0142] Product distribution (wt%) Direct heated pyrolysis Conventional steam cracking Hydrogen 0.98 0.92 Methane 12.97 14.88 Ethylene 34.10 32.11 Ethane 2.86 3.80 Propylene 17.11 16.06 Propane 0.38 0.46 Mixed C4's 11.23 9.64 Mixed C5's 4.86 4.21 C6+ 15.51 17.92 Total 100.00 100.00

[0143] Under the above process parameters, the process technology of this example can produce 100200 tons of ethylene per year and 50400 tons of propylene per year. As shown in Table 2, compared with the traditional steam cracking technology, the ethylene and propylene yields of the condensate oil cracking using the process technology of this example are increased by 6.2% and 6.5%, respectively, and the economic benefits are obvious.

[0144] Example 3

[0145] A single reactor for producing 100000 tons of ethylene per year:

[0146] The crude oil used in Example 1 is directly heated and cracked to produce low-carbon olefins. The specifications of the crude oil are shown in Table 3:

[0147] Table 3 Specifications of crude oil used in Example 3

[0148] Item Data Density (20°C) / (kg / m3) 3 )]]> 860.4 Kinematic viscosity (40°C) / (mm 2 / s) 5.8 Sulfur content / % 0.031 Pour point / °C 30 Carbon residue / % 0.22 Characteristic factor K 11.8 Carbon content / % 85.37 Hydrogen content / % 12.45

[0149] The method steps are as follows:

[0150] S1: Turn on the hydrogen-oxygen burner 1-1, and simultaneously introduce the mixture of hydrogen, water vapor, and oxygen into the hydrogen-oxygen burner 1-1. The hydrogen burns to generate high-temperature water vapor, which enters the combustion zone cylinder 1-3;

[0151] S2: The obtained high-temperature steam flows sequentially through the contracting cone 2-1 and the equal-diameter short section 2-2, mixing with the pyrolysis feedstock from the first feedstock inlet 2-3 and the second feedstock inlet 2-4. Part of the pyrolysis feedstock undergoes a pyrolysis reaction. The material then enters the expanding cone 3-1, mixing with the pyrolysis feedstock from the third feedstock inlet 3-2 and reacting further. The reaction product enters the quench zone 4, where 180°C quench oil is injected through the direct cooling medium inlet 4-3. The pyrolysis gas mixes thoroughly with the quench oil in the quench zone 4, and the quench oil cools the high-temperature pyrolysis gas to 350°C, terminating the pyrolysis reaction and yielding the target product. The target product enters the secondary cooling zone 5 for further cooling. The temperature of the mixture at the quench zone outlet 4-2 is controlled by controlling the injection rate of the quench oil.

[0152] In step S1, the hydrogen flow rate is 2910 kg / hr, the oxygen flow rate is 20955 kg / hr, and the water vapor flow rate is 77320 kg / hr.

[0153] In step S2, while the pyrolysis feedstock is being introduced into the first feedstock inlet 2-3, the second feedstock inlet 2-4, and the third feedstock inlet 3-2, atomizing water vapor is also introduced. The mass ratio of atomizing water vapor to pyrolysis feedstock is 0.3:1. The residence time of the material in the enlarged cone 3-1 is 0.06 s, and the material flow velocity at the equal-diameter short section 2-2 is 88 m / s.

[0154] like Figure 3 As shown, the hydrogen flow rate is 2910 kg / hr, the oxygen flow rate is 20955 kg / hr, and the water vapor flow rate is 77320 kg / hr. The oxygen and water vapor mix and enter the oxy-hydrogen burner 1-1, where they are mixed with hydrogen and combusted to generate high-temperature water vapor at 1300℃. Crude oil is injected into the mixing pre-reaction zone 2 at a flow rate of 48250 kg / hr. The crude oil mixes with the high-temperature water vapor, which directly transfers heat to the crude oil, rapidly raising its temperature to 850-890℃ and causing a rapid cracking reaction to produce cracked gas. The temperature of the cracked gas at the main reaction zone outlet 3-3 is approximately 790℃. Quenching oil, injected through the direct cooling medium inlet 4-3 at a temperature of 195℃, is injected. The cracked gas mixes thoroughly with the quenching oil in the quenching zone 4, resulting in a mixed temperature of 350℃. The temperature of the mixture at the quenching zone outlet 4-2 can be controlled by adjusting the amount of injected quenching oil. The mixture then enters the subsequent system for further separation.

[0155] Table 4. Comparison of product distribution between direct heating cracking of crude oil and steam cracking using a conventional tubular furnace in Example 3.

[0156] Product distribution (wt%) Direct heated pyrolysis Conventional steam cracking Hydrogen 0.67 0.64 Methane 8.67 10.15 Ethylene 25.91 24.35 Ethane 2.36 2.98 Propylene 15.06 14.12 Propane 0.34 0.38 Mixed C4's 11.28 10.24 Mixed C5's 5.91 5.61 C6+ 29.80 31.53 Total 100.00 100.00

[0157] Under the above process parameters, the process technology can produce 100,200 tons of ethylene and 5,810 tons of propylene per year. As can be seen from Table 4, when cracking crude oil, compared with the traditional steam cracking technology, the ethylene and propylene yields are increased by 6.4% and 6.65%, respectively, and the economic benefits are obvious.

[0158] Example 4:

[0159] 5,000 tons of ethylene reactor per year:

[0160] The reactor used in this example is mostly the same as that in Example 1, except that the heat exchange cylinder 4-7 of the quenching zone 4 of the reactor in this example is provided with one indirect heat exchanger 4-6, as shown in Figure 2 The quenching zone inlet 4-1 is connected with the main reaction zone outlet 3-3, the indirect heat exchanger 4-6 is a double-sleeve quenching heat exchanger, which adopts a double-sleeve structure, the heat exchange pipe diameter is Φ51mm, the number of heat exchange pipes is 198, the cooling medium is water, and the cooling medium enters from the indirect cooling medium inlet 4-4 and the steam-water mixture is led out from the indirect cooling medium outlet 4-5.

[0161] In this example, typical naphtha is used for direct heating cracking to produce low-carbon olefins. The specifications of naphtha are shown in Table 5.

[0162] Table 5 Specifications of naphtha in Example 4

[0163] Item Naphtha Relative density (20 / 4°C) 0.69 ASTM distillation IBP 40℃ 50 vol% 85℃ EBP 170℃ PONA wt% Paraffins ≥70 Of which n-paraffins ≥30 Olefins ≤1 Naphthenes ≤25 Aromatics ≤6

[0164] The method comprises the following steps:

[0165] S1: Start the oxyhydrogen burner 1-1, and simultaneously introduce a mixture of hydrogen and water vapor and oxygen into the oxyhydrogen burner 1-1, and the hydrogen is burned to produce high-temperature water vapor which enters the combustion zone cylinder 1-3;

[0166] S2: The obtained high-temperature water vapor flows through the converging cone body 2-1 and the equal-diameter short section 2-2 in sequence, mixes with the cracking raw materials from the first raw material inlet 2-3 and the second raw material inlet 2-4 in sequence, part of the cracking raw materials undergoes cracking reaction, and then the material enters the expanding cone body 3-1, mixes with the cracking raw materials from the third raw material inlet 3-2 and further reacts, the reaction product enters the quenching zone 4, the temperature of the mixture is reduced to 375℃ after heat exchange, the reaction is terminated to obtain the target product, and then the mixture enters the subsequent secondary cooling zone 5 for further cooling.

[0167] In step S1, the hydrogen flow rate is 1256 kg / hr, the oxygen flow rate is 9120 kg / hr, and the water vapor flow rate is 30060 kg / hr.

[0168] In step S2, the first raw material inlet 2-3, the second raw material inlet 2-4 and the third raw material inlet 3-2 are connected with the pyrolysis raw material and the atomizing water vapor at the same time, and the mass ratio of the atomizing water vapor to the pyrolysis raw material is 0.2:1. The residence time of the material in the expanding cone 3-1 is 0.05s, and the flow rate of the material at the equal-diameter short section 2-2 is 90m / s.

[0169] In step S2, the cooling medium of the quenching zone 4 is water, the temperature of the water is 310℃, and the pressure is 120Mpa. The steam-water mixture is led out from the indirect cooling medium outlet 4-5, and the mass ratio of the steam to the water is 1:9. The temperature of the mixture at the outlet of the quenching zone 4-2 is 375℃.

[0170] The hydrogen flow rate is 1256kg / hr, the oxygen flow rate is 9120kg / hr, and the water vapor flow rate is 30060kg / hr. As shown in FIG. 1, the oxygen and the water vapor are mixed and then introduced into the hydrogen-oxygen burner 1-1. In the hydrogen-oxygen burner 1-1, the hydrogen is mixed with the oxygen and water vapor to generate high-temperature water vapor, and the temperature of the high-temperature water vapor is 1400-1450℃. Figure 4 The naphtha is introduced into the mixed pre-reaction zone 2, and the flow rate of the naphtha is 20440kg / hr. The naphtha is mixed with the high-temperature water vapor in the mixed pre-reaction zone 2. The high-temperature water vapor directly transfers heat to the naphtha, and the temperature of the naphtha is rapidly increased to 860-900℃ and then the naphtha is rapidly cracked to generate the cracking gas. The temperature of the cracking gas at the outlet of the main reaction zone 3-3 is about 810℃.

[0171] Then, the cracking gas is introduced into the indirect heat exchanger 4-6. After passing through the indirect heat exchanger 4-6, the waste heat of the cracking gas is recovered to generate high-pressure steam, and at the same time, the cracking gas is cooled to about 380℃. Then, the cracking gas is introduced into the secondary cooling zone 5, and the cracking gas is cooled to 220℃ by the quenching oil introduced by the oil quenching device in the secondary cooling zone 5. Then, the cracking gas is sent to the subsequent system for further heat recovery and component separation.

[0172] Under the above process parameters, the process technology can produce 50000 tons of ethylene and 25300 tons of propylene per year. As shown in Table 6, compared with the traditional steam cracking technology, the yield of ethylene and propylene is increased by 6.4% and 7.8% respectively when the naphtha is directly heated and cracked by using the process technology, and the economic benefit is obvious.

[0173] Table 6 Comparison of product distribution between the direct heating and cracking of naphtha and the traditional tubular furnace steam cracking

[0174] Product distribution (wt%) Direct heated pyrolysis Conventional steam cracking Hydrogen 1.08 1.03 Methane 14.89 16.11 Ethylene 30.58 28.73 Ethane 2.55 2.93 Propylene 15.49 14.37 Propane 0.27 0.32 Mixed C4's 10.73 9.77 Mixed C5's 3.95 3.61 C6+ 20.46 23.13 Total 100.00 100.00

[0175] Example 5:

[0176] The direct heating and cracking unit for producing 200000 tons of ethylene per year:

[0177] As Figure 5 shown, the reactors in Example 4 are used in parallel, 5 units in a group, which can form a cracking reaction unit with an annual output of 200,000 tons, in which 4 reactors are online, and 1 reactor is in the state of burning or standby. For an ethylene plant with an annual output of 1 million tons of ethylene, 5 such cracking reaction units (equivalent to six traditional ethylene cracking furnaces) can meet the needs of actual production, realizing the large-scale of direct heating cracking production of low-carbon olefin devices.

[0178] Example 6:

[0179] The reactors in Example 3 are used in parallel, 2 units in a group, which can easily form a cracking reaction unit with an annual output of 200,000 tons of ethylene. For an ethylene plant with an annual output of 1.2 million tons of ethylene, 7 such cracking reaction units can meet the needs of actual production, realizing the large-scale of direct heating cracking production of low-carbon olefin devices.

[0180] Example 7:

[0181] Most of them are the same as in Example 1, except that in this example, the high-temperature brick layer of the inner wall of the combustion zone cylinder 1-3 is changed to a water jacket structure, and circulating cooling water is circulated between the jackets to protect the inner wall of the combustion zone cylinder 1-3.

[0182] Example 8:

[0183] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by ethane with equal flow rate.

[0184] Example 9:

[0185] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by propane with equal flow rate.

[0186] Example 10:

[0187] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by n-butane with equal flow rate.

[0188] Example 11:

[0189] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by liquefied petroleum gas with equal flow rate.

[0190] Example 12:

[0191] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by C5 with equal flow rate.

[0192] Example 13:

[0193] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by diesel oil at the same flow rate.

[0194] Example 14:

[0195] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by hydrogenated tail oil at the same flow rate.

[0196] Example 15:

[0197] Most of them are the same as in Example 2, except that in this example, the condensate is replaced by residual oil at the same flow rate.

[0198] Example 16:

[0199] Most of them are the same as in Example 2, except that in this example, the "mass ratio of atomizing steam to cracking raw material is 0.2:1" is replaced by "mass ratio of atomizing steam to cracking raw material is 0.1:1".

[0200] Example 17:

[0201] Most of them are the same as in Example 2, except that in this example, the "mass ratio of atomizing steam to cracking raw material is 0.2:1" is replaced by "mass ratio of atomizing steam to cracking raw material is 5:1".

[0202] Example 18:

[0203] Most of them are the same as in Example 2, except that in this example, the "residence time is 0.05s" is replaced by "residence time is 0.01s".

[0204] Example 19:

[0205] Most of them are the same as in Example 2, except that in this example, the "residence time is 0.05s" is replaced by "residence time is 0.5s".

[0206] Example 20:

[0207] Most of them are the same as in Example 2, except that in this example, the "material flow rate is 80m / s" is replaced by "material flow rate is 50m / s".

[0208] Example 21:

[0209] Most of them are the same as in Example 2, except that in this example, the "material flow rate is 80m / s" is replaced by "material flow rate is 200m / s".

[0210] Example 22:

[0211] The same as in Example 2 except that the volume ratio of the oxygen and water vapor introduced in Step S1 was adjusted to 1:10 in this example.

[0212] The foregoing description of the examples has been presented for the purposes of illustration and description. It is apparent to those skilled in the art that various modifications can be practiced as set forth in the foregoing description in conformance with the general principles set forth herein. Accordingly, the examples are not intended to be limited to that precisely as shown and described, and the examples are intended to include all possible combinations and modifications thereof falling within the scope of the disclosure.

Claims

1. A process for the production of lower olefins by direct heating of a hydrocarbon feedstock by a heat carrier, characterized in that, The reactor used in the method comprises: a combustion zone (1) for providing high-temperature water vapor, which comprises a combustion zone cylinder (1-3) with one end closed, and the combustion zone cylinder (1-3) is provided with a hydrogen-oxygen burner (1-1); a mixing pre-reaction zone (2) downstream of the combustion zone (1) for mixing raw materials and high-temperature water vapor, which comprises a converging cone body (2-1) and an equal-diameter short section (2-2), the flared end of the converging cone body (2-1) is connected with the end of the combustion zone cylinder (1-3) which is not closed, the narrow end of the converging cone body (2-1) is connected with one end of the equal-diameter short section (2-2), the converging cone body (2-1) is provided with a first raw material inlet (2-3), and the equal-diameter short section (2-2) is provided with a second raw material inlet (2-4); a main reaction zone (3) downstream of the mixing pre-reaction zone (2), which comprises an expanding cone body (3-1), the narrow end of the expanding cone body (3-1) is connected with the other end of the equal-diameter short section (2-2), and the expanding cone body (3-1) is provided with a third raw material inlet (3-2); a quenching zone (4) downstream of the main reaction zone (3) for stopping the cracking reaction; The method comprises the following steps: S1: turn on the hydrogen-oxygen burner (1-1), simultaneously introduce hydrogen and oxygen into the hydrogen-oxygen burner (1-1) respectively, hydrogen burns, and the generated high-temperature water vapor enters the combustion zone cylinder (1-3); S2: the obtained high-temperature water vapor flows through the converging cone body (2-1) and the equal-diameter short section (2-2) in sequence, mixes with the cracking raw materials from the first raw material inlet (2-3) and the second raw material inlet (2-4) in sequence, part of the cracking raw materials undergoes a cracking reaction, then the material enters the expanding cone body (3-1), mixes with the cracking raw materials from the third raw material inlet (3-2) and further reacts, and the reaction product enters the quenching zone (4) for cooling to obtain the target product; The flow mass ratio of hydrogen to oxygen is 2220:15996, or 2910:20955, or 1256:9120.

2. The process for the production of lower olefins by direct heating of hydrocarbons by a heat carrier according to claim 1, characterized in that, The hydrogen-oxygen burner (1-1) is provided with a plurality of hydrogen-oxygen burners (1-1), and the plurality of hydrogen-oxygen burners (1-1) are arranged at equal intervals around the central axis of the combustion zone cylinder (1-3) on the side wall of the combustion zone cylinder (1-3) or at the central part of the closed end of the combustion zone cylinder (1-3).

3. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, The inner wall of the combustion zone cylinder (1-3) is further provided with a layer of high-temperature resistant heat insulation material.

4. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, The combustion zone cylinder (1-3) has a double-jacket structure, and a cooling medium is circulated in the jacket.

5. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, The first raw material inlet (2-3) is provided with a plurality of first raw material inlets (2-3), and the plurality of first raw material inlets (2-3) are arranged at equal intervals around the central axis of the converging cone body (2-1) on the side wall of the converging cone body (2-1); The second raw material inlet (2-4) is provided with a plurality of second raw material inlets (2-4), and the plurality of second raw material inlets (2-4) are arranged at equal intervals around the central axis of the equal-diameter short section (2-2) on the side wall of the equal-diameter short section (2-2); The third raw material inlet (3-2) is provided with a plurality of third raw material inlets (3-2) which are arranged at the side wall of the enlarged cone body (3-1) at equal intervals around the central axis of the enlarged cone body (3-1).

6. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, The quenching zone (4) comprises a heat exchange cylinder (4-7), one end of the heat exchange cylinder (4-7) is connected with the flared end of the enlarged cone body (3-1), and the heat exchange cylinder (4-7) is provided with a direct cooling medium inlet (4-3) or an indirect heat exchanger (4-6).

7. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, In step S1, water vapor is also introduced while oxygen is introduced, and the mixed volume ratio of oxygen to water vapor is 1:(0-10) and is not 1:

0. In step S1, the temperature of high-temperature water vapor at the outlet of the combustion zone cylinder (1-3) is 1000-1500℃.

8. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, In step S2, the cracking raw material is one or more of ethane, propane, n-butane, liquefied petroleum gas, carbon five, naphtha, diesel, hydrogenated tail oil, condensate oil, residual oil or crude oil. In step S2, while the cracking raw material is introduced, atomizing water vapor is also introduced at the first raw material inlet (2-3), the second raw material inlet (2-4) and the third raw material inlet (3-2), and the mass ratio of the atomizing water vapor to the cracking raw material is (0.1-5):

1. In step S2, the residence time of the material in the enlarged cone body (3-1) is 0.01-0.5s, and the temperature of the reaction product at the outlet of the main reaction zone (3-3) is 600-900℃. In step S2, the flow rate of the material at the equal-diameter short section (2-2) is 50-200m / s.

9. The process for the production of lower olefins by direct heating of hydrocarbons with a heat carrier according to claim 1, characterized in that, In step S2, after the reaction product enters the quenching zone (4), the reaction product is cooled by directly spraying a cooling medium or using an indirect heat exchange method. In step S2, after the reaction product is cooled by the quenching zone (4), the temperature of the reaction product is 300-600℃.

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