CN217600663U - Reactor for preparing low-carbon olefin by cracking hydrocarbons by directly heating heat carrier - Google Patents

Abstract

The utility model relates to a reactor for preparing low carbon olefin by cracking hydrocarbons by directly heating heat carriers, which comprises a combustion area, a mixed pre-reaction area positioned at the lower reaches of the combustion area, a main reaction area positioned at the lower reaches of the mixed pre-reaction area and a quenching area positioned at the lower reaches of the main reaction area. When the reactor is used, the reactor comprises the following steps: s1: introducing hydrogen, and a mixture of water vapor and oxygen into an oxyhydrogen combustor respectively and simultaneously, and introducing high-temperature water vapor generated by hydrogen combustion into a combustion zone cylinder; s2: high-temperature water vapor sequentially flows through the contraction conical body and the equal-diameter short joint to be mixed with the raw materials from the first raw material inlet and the second raw material inlet, part of the raw materials are cracked, then the materials enter the expansion conical body to be mixed and reacted with the raw materials from the third raw material inlet, and a reaction product enters the quenching zone to be cooled to obtain a target product. Compared with the prior art, the reactor of the utility model has the characteristics of wide raw material application range, high selectivity of target products and the like.

Description

Reactor for preparing low-carbon olefin by cracking hydrocarbons by directly heating heat carrier

Technical Field

The utility model belongs to the technical field of olefin production equipment, a reactor for preparing low carbon olefin by cracking hydrocarbons through direct heating of heat carrier is related to.

Background

The ethylene cracking furnace is an important equipment unit in the petrochemical industry, and more than 90% of ethylene is produced by the ethylene cracking furnace globally. The existing ethylene cracking furnace consists of a radiation chamber, a convection chamber, a quenching boiler, a burner and the like, wherein the burner is arranged in the radiation chamber, and fuel is combusted through the burner to generate a large amount of high-temperature flue gas. The radiant furnace tube is suspended in the radiant chamber, the high-temperature flue gas transfers heat into the radiant furnace tube through radiation heat transfer in the radiant chamber, and a medium in the radiant furnace tube is heated, so that the raw material is subjected to cracking reaction to generate low-carbon olefin. In the process, the high-temperature flue gas heat is transferred from the outside of the pipe to the inside of the pipe to heat the medium, and the high-temperature flue gas is not directly contacted with the materials in the pipe, which is called indirect heat exchange. The heat transfer intensity in the process is limited by the highest use temperature of the material of the radiation furnace tube, the cracking furnace is forced to stop frequently due to coking in the radiation furnace tube, the service life of the radiation furnace tube is generally only 5-6 years when the radiation furnace tube is used at high temperature for a long time, the hot material rate of the cracking furnace is generally only 92-94%, and as the raw materials need to be preheated and vaporized in a convection section heat exchange tube, the used raw materials are limited to a certain extent.

In order to eliminate the defects of the conventional cracking furnace and expand the source range of the cracking raw materials, a great deal of research on the research of cracking olefins by directly heating hydrocarbons through a heat carrier by technicians in the last 70 th century has been carried out, and in recent years, the technicians also carry out certain exploratory research on a method for preparing olefins by directly cracking crude oil.

The cracking of hydrocarbons by directly heating the heat carrier refers to that the high-temperature heat carrier is directly mixed with cracking raw materials, the heat carrier directly transfers heat to the cracking raw materials in a mode of directly contacting the cracking raw materials, and the cracking reaction is carried out after the cracking raw materials reach the temperature for carrying out the cracking reaction.

CN 101875591A discloses a method for preparing low-carbon olefin by hydrocarbon cracking. The method is that preheated hydrocarbon raw material, hydrogen and oxygen-containing gas are introduced into a plurality of units comprising a hydrogen-containing catalytic combustion device and an adiabatic reaction device; in the hydrogen catalytic combustion device, the hydrogen is combusted to provide energy so as to raise the temperature of the mixed material to the temperature required by the cracking reaction; in an adiabatic reaction device, carrying out thermal cracking reaction to generate a material flow containing low-carbon olefin; finally, after the heat is recovered by a quenching device, various low-carbon olefin products are obtained by a separation system. The technology adopts a selective hydrogen combustion catalyst, and introduces a mixture of hydrogen, oxygen and cracking raw materials into a hydrogen catalyst device, so that the hydrogen in the hydrogen catalyst device is subjected to catalytic combustion reaction to provide heat for the cracking reaction.

US3161695 discloses a process for preparing alkynes, the reactor is a round tube type, the wall of the round tube has a certain heat conductivity, the outside of the round tube is an annular high temperature resistant material, a certain gap is provided between the annular high temperature resistant material and the outer wall of the round tube reactor, the gap is a combustion chamber, hydrogen and oxygen are combusted in the combustion chamber, go up along the combustion chamber space, and then are mixed with raw materials entering from the top end of the round tube reactor, and enter the round reaction tube, and a cracking reaction occurs in the tube, the wall of the round reactor has a certain heat conductivity, and a certain amount of heat can be supplemented for the cracking reaction.

The direct crude oil cracking technology disclosed in WO 2004/005431 A1, US7578929B2, etc. is characterized in that crude oil is used as a cracking raw material, but certain requirements are imposed on the properties of the crude oil, and meanwhile, heavy end components in the crude oil need to be cut off in the processing process, and only a part of the crude oil suitable as the cracking raw material is sent into a traditional tubular steam cracking furnace for cracking, so that the source of the cracking raw material is expanded to a certain extent.

In conclusion, the equipment for preparing the low-carbon olefin by heating hydrocarbon cracking in the prior art generally has the problems of narrow raw material application range, long reaction retention time, short operation period, low thermal efficiency, large greenhouse gas emission, catalyst requirement during use and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a reactor for preparing low carbon olefin by cracking hydrocarbons by directly heating heat carriers to overcome the defects of narrow raw material application range, long reaction residence time, short operation period, low thermal efficiency, large greenhouse gas emission or catalyst requirement in use of the prior art for preparing low carbon olefin by cracking hydrocarbons by heating hydrocarbons. In view of the not enough of current cracking technique existence, the utility model provides a reactor of low carbon olefin is prepared in pyrolysis of heat carrier direct heating hydrocarbons, this reactor adopts oxyhydrogen burning to generate high temperature steam when using, and high temperature steam mixes with pyrolysis raw materials direct contact to transmit the heat for the pyrolysis raw materials rapidly, make the pyrolysis raw materials take place the thermal cracking reaction and produce low carbon olefin. The utility model discloses reactor raw materials application scope is wide, the thermal efficiency is high, no greenhouse gas discharges, can satisfy conditions such as required "high temperature of schizolysis reaction, short dwell time, low hydrocarbon partial pressure" to can obviously promote the selectivity of purpose alkene, have longer operating cycle.

The purpose of the utility model can be realized by the following technical proposal:

a reactor for preparing low-carbon olefin by cracking hydrocarbons through direct heating by a heat carrier comprises:

combustion zone for providing high temperature water vapor: the device comprises a combustion zone cylinder with one closed end, wherein the combustion zone cylinder is provided with an oxyhydrogen burner;

a mixing pre-reaction zone downstream of the combustion zone for mixing feedstock and high temperature steam: the combustion zone cylinder comprises a contraction conical body and an equal-diameter short section, wherein the flaring end of the contraction conical body is connected with the unsealed end of the combustion zone cylinder, the closing end of the contraction conical body is connected with one end of the equal-diameter short section, the contraction conical body is provided with a first raw material inlet, and the equal-diameter short section is provided with a second raw material inlet;

a primary reaction zone located downstream of the mixing pre-reaction zone: the pipe joint comprises an expanding conical body, wherein the closing end of the expanding conical body is connected with the other end of the equal-diameter short section, and the expanding conical body is provided with a third raw material inlet;

a quench zone downstream of said main reaction zone for stopping the cracking reaction.

Furthermore, the hydrogen-oxygen burners are provided with a plurality of hydrogen-oxygen burners which are arranged on the side wall of the combustion zone cylinder or in the central part of the closed end of the combustion zone cylinder at equal intervals around the central axis of the combustion zone cylinder.

Furthermore, when the oxyhydrogen burner is arranged on the side wall of the combustion zone cylinder, the included angle formed by the central line of the flame sprayed by the oxyhydrogen burner and the circumferential tangent line of the side wall of the combustion zone cylinder is 0-180 degrees.

Furthermore, when the oxyhydrogen burner is arranged at the central part of the closed end of the combustion zone cylinder, the center line of the flame sprayed by the oxyhydrogen burner is parallel to the central axis of the combustion zone cylinder.

Furthermore, when a plurality of oxyhydrogen burners are arranged on the side wall of the combustion zone cylinder, a plurality of oxyhydrogen burners are arranged in a plurality of layers.

Furthermore, the inner wall of the combustion zone cylinder body is also provided with a high-temperature resistant heat insulation material layer.

Furthermore, the high-temperature resistant heat insulation material layer is one or a combination of a high-temperature resistant fiber layer, a high-temperature resistant brick layer or a high-temperature resistant castable layer.

Furthermore, the combustion zone cylinder is of a double-layer jacket structure, and a cooling medium is introduced into the jacket.

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

Furthermore, the first raw material inlets are provided with a plurality of first raw material inlets which are arranged on the side wall of the contraction cone body at equal intervals around the central axis of the contraction cone body.

Furthermore, the plurality of first raw material inlets are arranged in a multilayer manner, and each layer is provided with 2-4 first raw material inlets.

Further, the first raw material inlet is vertically disposed at a sidewall of the convergent cone.

Furthermore, a plurality of second raw material inlets are arranged on the second raw material inlet, and the second raw material inlets surround the central axis of the constant-diameter short section and are arranged on the side wall of the constant-diameter short section at equal intervals.

Furthermore, the plurality of second raw material inlets are arranged in a multilayer manner, and each layer is provided with 2-4 second raw material inlets.

Furthermore, the included angle between the central axis of the second raw material inlet and the side wall of the constant diameter short section is 10-170 degrees.

Furthermore, the third raw material inlets are arranged on the side wall of the expanding conical body at equal intervals around the central axis of the expanding conical body.

Furthermore, the plurality of third raw material inlets are arranged in a multilayer manner, and each layer is provided with 2-4 third raw material inlets.

Furthermore, the included angle between the central axis of the third raw material inlet and the side wall of the enlarged cone is 10-170 degrees.

Furthermore, the included angle between the side wall of the equal-diameter short section and the side wall of the enlarged conical body is 100-170 degrees, and 115-135 degrees can be selected.

Furthermore, the included angle between the side wall of the contraction conical body and the side wall of the combustion zone cylinder body is 100-170 degrees, and 120-150 degrees can be selected.

Furthermore, the quenching zone comprises a heat exchange cylinder, and one end of the heat exchange cylinder is connected with the flaring end of the expanding conical body.

Furthermore, the heat exchange cylinder is provided with a direct cooling medium inlet.

Furthermore, the heat exchange cylinder is provided with an indirect heat exchanger.

Further, a secondary cooling zone for further cooling the cracked product is provided downstream of the quench zone.

Further, the secondary cooling zone is provided with a quencher, and a cooling medium is injected through the quencher and cools the cracked product.

The term "short" in the constant diameter sub is merely descriptive words and does not refer to a specific length.

The utility model discloses the reactor is used for the pyrolysis of direct heating hydrocarbons to prepare low carbon olefin, including following step:

s1: starting an oxyhydrogen burner, introducing hydrogen and oxygen into the oxyhydrogen burner respectively and simultaneously, combusting the hydrogen, and introducing the generated high-temperature water vapor into a combustion zone cylinder;

s2: and the obtained high-temperature water vapor sequentially flows through the shrinkage conical body and the equal-diameter short section, and is sequentially mixed with the cracking raw materials from the first raw material inlet and the second raw material inlet, a part of the cracking raw materials are subjected to cracking reaction, then the material enters the expansion conical body, is mixed with the cracking raw material from the third raw material inlet and is further reacted, and the reaction product enters a quenching zone to be cooled, so that the target product is obtained.

Further, in the step S1, while introducing oxygen, water vapor is also introduced, and the volume ratio of the oxygen to the water vapor is 1: (0 to 10) and is not 1:0. in the oxyhydrogen burner, hydrogen is introduced into a central channel of the oxyhydrogen burner, and a mixture of oxygen and water vapor is introduced into a sleeve outside the central channel.

Further, in the step S1, the temperature of the high-temperature steam at the outlet of the combustion zone cylinder is 1000 to 1500 ℃, and may be 1200 to 1400 ℃. The utility model discloses an adjust the proportion of the oxygen that lets in and vapor, the temperature of adjusting combustion area barrel exit high temperature vapor is 1000 ~ 1500 ℃.

Further, in step S2, the cracking feedstock is one or more of ethane, propane, n-butane, liquefied Petroleum Gas (LPG), carbon five, naphtha, diesel oil, hydrogenated tail oil, condensate oil, residual oil, or crude oil.

Further, in step S2, atomizing water vapor (or referred to as protective water vapor) is also introduced into the first raw material inlet, the second raw material inlet and the third raw material inlet while the cracking raw material is introduced, and the mass ratio of the atomizing water vapor to the cracking raw material is (0.1-5): 1. the atomizing water vapor is water vapor for atomizing the cracking material, but when the cracking material is not fed, the water vapor is fed first to protect the nozzle when the high temperature water vapor generated by oxyhydrogen combustion is in the combustion zone cylinder immediately before the cracking material is fed.

Further, in the step S2, the retention time of the material in the expanded conical body is 0.01-0.5S, optionally 0.05-0.15S, and the temperature of the reaction product at the outlet of the main reaction zone is 600-900 ℃. The cracking reaction is carried out at the position of the expanding cone body, a large amount of micromolecule products are generated, the mole number of the reaction products is increased more, the expanding cone body is adopted to ensure that the mixture has smaller friction resistance drop while being at higher flow velocity, and the retention time of the materials in the expanding cone body is determined by two factors of the internal volume of the expanding cone body and the flow velocity of the materials at the position.

Further, in the step S2, the material flow speed at the equal-diameter short section is 50-200m/S, and can be selected to be 80-120 m/S. During original design, the volume of the equal-diameter short section is calculated according to parameters such as the property of the raw material, the flow of water vapor, the temperature and the pressure at the position, and the like, so that the flow speed is ensured to be within the range of 50-200 m/s.

Further, in step S2, after the reaction product enters the quenching zone, the reaction product is cooled by directly injecting a cooling medium or by indirect heat exchange.

Further, in step S2, the temperature of the reaction product is 300 to 600 ℃ after the reaction product is cooled by the quenching zone.

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 to 250 ℃ by a cooling medium sprayed in the secondary cooling zone.

In step S2, injecting cracking raw materials into a contraction cone body of a mixed pre-reaction zone to mix the cracking raw materials with high-temperature water vapor, directly transferring heat to the cracking raw materials by the high-temperature water vapor, carrying out cracking reaction on part of hydrocarbons reaching the cracking reaction temperature in the cracking raw materials to form a mixture consisting of the water vapor, the cracking raw materials and reaction products, wherein the temperature of the mixture is 1000-1100 ℃, then the mixture enters an equal-diameter short section of the mixed pre-reaction zone, and the cracking raw materials are further injected into a second raw material inlet of the equal-diameter short section, so that the mixing, heat transfer and partial cracking reaction of the materials are further strengthened.

In step S2, after the material enters the main reaction zone, the cracking raw material is continuously injected into the third raw material inlet of the enlarged cone, the small molecular products are increased along with the progress of the cracking reaction, the mole number of the mixture is rapidly increased, the equilibrium temperature of the mixture after passing through the enlarged cone is 600-900 ℃, optionally 750-850 ℃, and the pressure is 0.05-2.5 MpaG.

In step S2, the reaction product enters a quenching zone for cooling, and different cooling methods can be selected according to different cracking raw materials. When the cracking raw material is light, the waste heat of the reaction mixture can be recovered by adopting an indirect heat exchange mode; when the raw materials are heavy, the reaction mixture can be cooled by directly spraying a cooling medium, and then the waste heat of the reaction mixture is recovered. The temperature of the reaction mixture after heat recovery through the quench zone is between 300 and 600 c, optionally 350 to 450 c. In the field, the weight of the raw material is usually judged by taking the specific gravity of the raw material as a reference, and the weight ratio is usually: ethane, propane, LPG, naphtha all belong to the raw materials than light, and diesel oil, hydrogenation tail oil, crude oil belong to the raw materials than heavy, the utility model discloses use raw materials proportion 0.8 as the boundary, raw materials proportion is less than 0.8 and can be called light, be higher than 0.8 and can be called heavy.

In step S2, the reaction mixture after heat recovery in the quenching zone enters a secondary cooling zone, key equipment in the secondary cooling zone is a quencher, cooling medium is sprayed in through the quencher, the cooling medium can be water or hydrocarbon, after the cooling medium is sprayed in, the reaction mixture is cooled to 180-250 ℃, and the cooled reaction mixture enters a subsequent separation system for further low-temperature heat recovery and component separation.

When the material leaves the expanded cone of the main reaction zone, the temperature is still as high as about 800 ℃, and a large amount of secondary reactions occur in the material under the state for a long time, wherein the secondary reactions refer to reactions such as dehydrogenation and polycondensation of unstable molecules such as olefin and diene, and the like, so that the target olefin is reduced, therefore, the purpose of arranging the quenching zone at the outlet of the main reaction zone is to rapidly cool the reaction product, and the secondary reactions can be terminated when the temperature is generally considered to be below 600-650 ℃.

Compared with the prior art, the utility model has the advantages of it is following:

(1) The utility model discloses the reactor utilizes the high temperature steam that oxyhydrogen burning produced to directly mix with the schizolysis raw materials when using, makes the raw materials reach the required temperature of schizolysis reaction in the very short time, and reaction dwell time shortens more than 50% compared with prior art, and the high temperature steam that oxyhydrogen burning produced still plays the effect that reduces hydrocarbon partial pressure to the selectivity of purpose product has been improved;

(2) The reactor adopts a direct heating mode to prepare low-carbon olefin, has high thermal efficiency, can not generate coking in a heat exchange pipe, has wider adaptability of raw materials, and has longer running period;

(3) The reactor of the utility model adopts high-temperature water vapor generated by hydrogen and oxygen combustion as a carrier for direct heating, and does not discharge greenhouse gases and other pollutants;

(4) The reactor is used for preparing low-carbon olefin without adopting a catalyst.

Drawings

FIG. 1 is a schematic diagram of the structure of the reactor of examples 1-3 (direct cooling);

FIG. 2 is a schematic diagram of the structure of the reactor of example 4 (indirect heat exchange);

FIG. 3 is a flow chart of the process for preparing low-carbon olefins by cracking hydrocarbons through direct heating with a heat carrier in example 2-3;

FIG. 4 is a flow chart of the process for preparing low carbon olefins by cracking hydrocarbons directly heated by a heat carrier in example 4;

FIG. 5 is a schematic diagram of the parallel use of 5 reactors in example 5;

FIG. 6 is a schematic diagram of the orientation of hydrogen and a mixture of water vapor and oxygen in an oxyhydrogen burner.

The notation in the figure is:

1-combustion zone, 1-1-oxyhydrogen combustor, 1-2-high temperature resistant brick layer, 1-3-combustion zone cylinder, 2-mixed pre-reaction zone, 2-1-contraction cone, 2-2-equal diameter short section, 2-3 first raw material inlet, 2-4 second raw material inlet, 3-main reaction zone, 3-1-expansion cone, 3-2-third raw material inlet, 3-3-main reaction zone outlet, 4-quench zone, 4-1-quench zone inlet, 4-2-quench 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 and 5-secondary cooling zone.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The embodiment of the present invention is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the following embodiments or examples, unless otherwise specified, functional components or structures are all conventional components or structures adopted in the art to achieve the corresponding functions.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description of the present invention, unless otherwise specified, the terms "first", "second", "third", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In order to overcome the defects of narrow raw material application range, long reaction residence time, short operation period, low thermal efficiency, large greenhouse gas emission or catalyst requirement in application of the equipment for preparing the low-carbon olefin by heating hydrocarbon cracking in the prior art, the utility model provides a reactor for preparing the low-carbon olefin by directly heating hydrocarbon cracking by a heat carrier, as shown in figures 1-2, the reactor comprises:

combustion zone 1 for providing high temperature water vapor: the device comprises a combustion zone cylinder 1-3 with one closed end, wherein the combustion zone cylinder 1-3 is provided with an oxyhydrogen burner 1-1;

a mixing pre-reaction zone 2 for mixing the feedstock and high temperature steam, located downstream of the combustion zone 1: the combustion zone cylinder comprises a contraction conical body 2-1 and an equal-diameter short section 2-2, wherein the flaring end of the contraction conical body 2-1 is connected with the unsealed end of the combustion zone cylinder 1-3, the closing end of the contraction conical body 2-1 is connected with one end of the equal-diameter short section 2-2, the contraction conical 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 located downstream of the mixing pre-reaction zone 2: the pipe joint comprises an enlarged conical body 3-1, wherein the closing end of the enlarged conical body 3-1 is connected with the other end of the equal-diameter short section 2-2, and the enlarged conical body 3-1 is provided with a third raw material inlet 3-2;

a quench zone 4 for stopping the cracking reaction downstream of said main reaction zone 3.

In some specific embodiments, the oxyhydrogen burner 1-1 is provided with a plurality of oxyhydrogen burners 1-1, and the plurality of oxyhydrogen burners 1-1 are arranged on the side wall of the combustion zone cylinder 1-3 or on the central part of the closed end of the combustion zone cylinder 1-3 at equal intervals around the central axis of the combustion zone cylinder 1-3.

In a more specific embodiment, referring to fig. 1-2, a plurality of oxyhydrogen burners 1-1 are arranged on the side wall of the combustion zone cylinder 1-3 at equal intervals around the central axis of the combustion zone cylinder 1-3, and the oxyhydrogen burners 1-1 are also arranged at the central part of the closed end of the combustion zone cylinder 1-3.

In a more specific embodiment, when the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 runs, the included angle formed by the central line of the flame sprayed by the oxyhydrogen burner and the circumferential tangent line of the side wall of the combustion zone cylinder 1-3 is 0-180 degrees; when the oxyhydrogen burner 1-1 arranged at the central part of the closed end of the combustion zone cylinder 1-3 is in operation, the central line of the flame sprayed by the oxyhydrogen burner is parallel to the central axis of the combustion zone cylinder 1-3.

In a more specific embodiment, when several hydrogen and oxygen burners 1-1 are arranged on the side wall of the combustion zone cylinder 1-3, several hydrogen and oxygen burners 1-1 are arranged in multiple layers.

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

In a more specific embodiment, the high-temperature resistant heat insulation material layer is one or more of a high-temperature resistant fiber layer, a high-temperature resistant brick layer 1-2 or a high-temperature resistant castable material layer.

In a more specific embodiment, referring to fig. 1, the inner wall of the combustion zone cylinder 1-3 is provided with a refractory brick layer 1-2.

In some embodiments, the combustion zone cylinders 1-3 are double-layer jacket structures, and cooling medium is introduced into the jackets.

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

In some specific embodiments, referring to fig. 1, 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 equally spaced around the central axis of the convergent cone 2-1 and are arranged on the side wall of the convergent cone 2-1.

In a more specific embodiment, a plurality of first raw material inlets 2-3 are arranged in a plurality of layers, and each layer is provided with 2 to 4 first raw material inlets 2-3.

In a more specific embodiment, the first raw material inlet 2-3 is vertically disposed at a sidewall of the converging cone 2-1.

In some specific embodiments, referring to fig. 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 on the side wall of the constant diameter short section 2-2 at equal intervals around the central axis of the constant diameter short section 2-2.

In a more specific embodiment, a plurality of second raw material inlets 2-4 are arranged in a plurality of layers, and each layer is provided with 2-4 second raw material inlets 2-4.

In a more specific embodiment, the included 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 10-170 degrees.

In some embodiments, referring to fig. 1, the third raw material inlet 3-2 is provided in a plurality of numbers, and the third raw material inlets 3-2 are arranged at equal intervals around the central axis of the enlarged cone 3-1 on the side wall of the enlarged cone 3-1.

In a more specific embodiment, a plurality of third material inlets 3-2 are arranged in a plurality of layers, and each layer is provided with 2-4 third material inlets 3-2.

In a more specific embodiment, the angle between the central axis of the third raw material inlet 3-2 and the side wall of the enlarged cone 3-1 is 10 to 170 °.

In some specific embodiments, the included angle between the side wall of the constant diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is 100-170 degrees, and can be selected to be 115-135 degrees.

In some embodiments, the side wall of the convergent cone 2-1 and the side wall of the combustion zone cylinder 1-3 are at an angle of 100 to 170 °, optionally 120 to 150 °.

In some embodiments, referring to fig. 1 or fig. 2, the quenching zone 4 comprises a heat exchange cylinder 4-7, and one end of the heat exchange cylinder 4-7 is connected to the flared end of the expanding cone 3-1.

In a more specific embodiment, referring to fig. 1, the heat exchange cylinder 4-7 is provided with a direct cooling medium inlet 4-3.

In a more specific embodiment, referring to fig. 2, the heat exchange cylinder 4-7 is provided with an indirect heat exchanger 4-6.

In some embodiments, referring to fig. 1, a secondary cooling zone 5 is provided downstream of the quench zone 4 for further cooling of the cracked product.

In a more specific embodiment, the secondary cooling zone 5 is provided with a quencher, by means of which a cooling medium is injected and cools the cleavage product.

The utility model discloses the reactor is used for the pyrolysis of direct heating hydrocarbons to prepare low carbon olefin, including following step:

s1: starting the oxyhydrogen burner 1-1, introducing hydrogen and a mixture of water vapor and oxygen into the oxyhydrogen burner 1-1 respectively, combusting the hydrogen, and introducing the generated high-temperature water vapor into a combustion zone cylinder 1-3;

s2: the obtained high-temperature water vapor sequentially flows through a contraction conical body 2-1 and an equal-diameter short joint 2-2, and is sequentially mixed with cracking raw materials from a first raw material inlet 2-3 and a second raw material inlet 2-4, a part of the cracking raw materials are subjected to cracking reaction, then the materials enter an expansion conical body 3-1, are mixed with the cracking raw materials from a third raw material inlet 3-2 and are subjected to further reaction, and reaction products enter a quenching zone 4 and are cooled to obtain target products.

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

In some specific embodiments, in step S1, steam is introduced simultaneously with the introduction of oxygen, and the mixing volume ratio of oxygen to steam is 1: (0 to 10) and is not 1:0.

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 to 1500 ℃, optionally 1200 to 1400 ℃. The utility model adjusts the temperature of the high-temperature water vapor at the outlet of the 1-3 of the combustion area barrel body to be 1000-1500 ℃ by adjusting the proportion of the introduced oxygen and the water vapor.

In some embodiments, in step S2, the cracking feedstock is one or more of ethane, propane, n-butane, liquefied Petroleum Gas (LPG), carbon five, naphtha, diesel, hydrogenated tail oil, condensate, residual oil, or crude oil.

In some specific embodiments, in step S2, atomizing water vapor (or referred to as protective water vapor) is also introduced into the first raw material inlet 2-3, the second raw material inlet 2-4, and the third raw material inlet 3-2 while introducing the cracking raw material, and a mass ratio of the atomizing water vapor to the cracking raw material is (0.1-5): 1.

in some embodiments, in step S2, the residence time of the material in the enlarged cone 3-1 is 0.01 to 0.5S, optionally 0.05 to 0.15S, and the temperature of the reaction product at the outlet 3-3 of the main reaction zone is 600 to 900 ℃.

In some specific embodiments, in step S2, the material flow rate at the constant diameter short section 2-2 is 50-200m/S, and optionally 80-120 m/S.

In some embodiments, in step S2, after the reaction product enters the quenching section 4, the reaction product is cooled by directly injecting a cooling medium or by indirect heat exchange.

In some embodiments, in step S2, the temperature of the reaction product after being cooled by the quenching section 4 is 300 to 600 ℃.

In some specific embodiments, in step S2, the reaction product is cooled by the quenching zone 4 and then enters the secondary cooling zone 5, and the cooling medium injected into the secondary cooling zone 5 further cools the reaction product to 180-250 ℃.

In the following embodiments, the oxyhydrogen burner 1-1 is operated by introducing hydrogen gas and a mixture of water vapor and oxygen gas into the oxyhydrogen burner 1-1 simultaneously, and the hydrogen gas and the mixture of water vapor and oxygen gas are moved in the oxyhydrogen burner 1-1 in the manner shown in FIG. 6, wherein the hydrogen gas is introduced into the central passage of the oxyhydrogen burner 1-1 and the mixture of oxygen gas and water vapor is introduced into the jacket outside the central passage of the oxyhydrogen burner 1-1.

Example 1:

the embodiment provides a reactor for preparing low-carbon olefin by cracking hydrocarbon through direct heating of a heat carrier, and as shown in figure 1, the reactor comprises a combustion zone 1, an oxyhydrogen burner 1-1, a high-temperature-resistant brick layer 1-2, a combustion zone cylinder 1-3, a mixed pre-reaction zone 2, a contraction 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 expansion 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.

The combustion zone 1 comprises a combustion zone cylinder 1-3 with one closed end; the mixed pre-reaction zone 2 is positioned at the downstream of the combustion zone 1, the mixed pre-reaction zone 2 comprises a contraction conical body 2-1 and an equal-diameter short section 2-2, the flaring end of the contraction conical body 2-1 is connected with the unsealed end of the combustion zone cylinder body 1-3, and the closing end of the contraction conical body 2-1 is connected with one end of the equal-diameter short section 2-2; the main reaction zone 3 is positioned at the downstream of the mixed pre-reaction zone 2, the main reaction zone 3 comprises an enlarged conical body 3-1, and the closing end of the enlarged conical body 3-1 is connected with the other end of the equal-diameter short section 2-2; the quenching zone 4 is positioned at the downstream of the main reaction zone 3, the quenching zone 4 comprises a heat exchange cylinder 4-7, one end of the heat exchange cylinder 4-7 is connected with the flaring end of the expanding conical body 3-1, and the heat exchange cylinder 4-7 is provided with a direct cooling medium inlet 4-3; the secondary cooling zone 5 is located downstream of the quenching zone 4, the outlet 4-2 of the quenching zone is connected to the secondary cooling zone 5, the secondary cooling zone 5 is provided with a quencher into which a cooling medium can be injected and which cools the cracked product from the quenching zone 4.

The oxyhydrogen burner 1-1 is provided with 5 oxyhydrogen burners, 1 oxyhydrogen burner 1-1 is arranged at the central part of the closed end of the combustion zone cylinder 1-3, and the other 4 oxyhydrogen burners 1-1 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. When the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 runs, the included angle formed by the central line of the flame sprayed by the oxyhydrogen burner and the circumferential tangent line of the side wall of the combustion zone cylinder 1-3 is 120 degrees. When the oxyhydrogen burner 1-1 arranged at the central part of the closed end of the combustion zone cylinder 1-3 is in operation, the central line of the flame sprayed by the oxyhydrogen burner is parallel to the central axis of the combustion zone cylinder 1-3.

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

The first raw material inlet 2-3 is provided with 4, and the 4 first raw material inlets 2-3 are arranged on the side wall of the contraction cone 2-1 at equal intervals around the central axis of the contraction cone 2-1. The first raw material inlet 2-3 is vertically disposed at a sidewall of the convergent cone 2-1.

The number of the second raw material inlets 2-4 is 4, and the 4 second raw material inlets 2-4 are arranged on the side wall of the constant diameter short section 2-2 at equal intervals around the central axis of the constant diameter short section 2-2. The included angle between the central axis of the second raw material inlet 2-4 and the side wall of the equal-diameter short section 2-2 is 90 degrees.

The third raw material inlet 3-2 is provided with 4, and the 4 third raw material inlets 3-2 are arranged on the side wall of the enlarged cone 3-1 at equal intervals around the central axis of the enlarged cone 3-1. The included angle between the central axis of the third raw material inlet 3-2 and the side wall of the enlarged conical body 3-1 is 90 degrees.

The included angle between the side wall of the equal-diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is 150 degrees. The included angle between the side wall of the contraction conical body 2-1 and the side wall of the combustion area cylinder body 1-3 is 120 degrees.

In this embodiment, the quenching zone 4 is a direct quenching type, as shown in fig. 1, an inlet 4-1 of the quenching zone is connected to an outlet 3-3 of the main reaction zone, and a cooling medium is injected through an inlet 4-3 of the direct cooling medium, 4 inlets 4-3 of the direct cooling medium are arranged at equal intervals around the central axis of the heat exchange cylinder 4-7, the cooling medium is quenching oil, and the quenching oil is mixed with the reaction mixture and then enters a secondary cooling zone 5 for further cooling.

Example 2:

annual 10 ten thousand ton ethylene single reactor:

in this example, the condensate was directly heated and cracked to produce light olefins by using the reactor of example 1. The specifications of the condensate are shown in table 1:

table 1 example 2 specification table for condensate

Item	Data of
		Density (20 ℃ C.)/(kg/m) 3 )	789.7
Kinematic viscosity (40 ℃ C.)/(mm) 2 /s)	2.299
		Sulfur content/%)	0.0143
Pour point/. Degree.C	19
		Carbon residue/%)	0.05
Flash point/. Degree.C	Flash fire at normal temperature
		Characteristic factor K	12.76
Carbon content/%)	83.18
		Content of hydrogen/%)	14.85

The method for preparing the low-carbon olefin by directly heating and cracking the condensate oil comprises the following steps:

s1: starting the oxyhydrogen combustor 1-1, introducing hydrogen and a mixture of water vapor and oxygen into the oxyhydrogen combustor 1-1 respectively, combusting the hydrogen, and introducing the generated high-temperature water vapor into a combustion zone cylinder 1-3;

s2: the obtained high-temperature water vapor sequentially flows through a contraction conical body 2-1 and an equal-diameter short joint 2-2 to be sequentially mixed with cracking raw materials from a first raw material inlet 2-3 and a second raw material inlet 2-4, part of the cracking raw materials are subjected to cracking reaction, then the materials enter an expansion conical body 3-1 to be mixed with the cracking raw materials from a third raw material inlet 3-2 and further react, a reaction product enters a quenching zone 4, quenching oil with the temperature of 180 ℃ is sprayed through a direct cooling medium inlet 4-3, the quenching oil is fully mixed with the quenching oil in the quenching zone 4, the quenching oil cools high-temperature cracking oil to 350 ℃, the cracking reaction is stopped to obtain a target product, and the target product enters a secondary cooling zone 5 to be further cooled. The temperature of the mixture at the exit 4-2 of the quench section is controlled by controlling the amount of quench oil injected.

In step S1, hydrogen flow rate: 2220kg/hr, oxygen flow rate: 15996kg/hr, steam flow: 59040kg/hr.

In the step S2, the cracking raw material is introduced into the first raw material inlet 2-3, the second raw material inlet 2-4 and the third raw material inlet 3-2, and simultaneously atomization steam is also introduced, wherein the mass ratio of the atomization steam to the cracking raw material is 0.2:1. the retention time of the material in the enlarged conical body 3-1 is 0.05s, and the material flow velocity at the equal-diameter short joint 2-2 is 80m/s.

As shown in fig. 3, hydrogen flow rate: 2220kg/hr, oxygen flow rate: 15996kg/hr, steam flow: 59040kg/hr, mixing oxygen with water vapor, feeding into oxyhydrogen burner 1-1, mixing with hydrogen in oxyhydrogen burner 1-1, and burning to generate high temperature water vapor at 1300 deg.C. And (2) spraying condensate oil into the mixing pre-reaction zone 2, wherein the flow rate of the condensate oil is 36800kg/hr, the condensate oil is mixed with high-temperature steam, the high-temperature steam directly transfers heat to the condensate oil, the condensate oil is quickly heated to 830-860 ℃ and is quickly subjected to cracking reaction to produce cracked gas, and the temperature of the cracked gas at the position 3-3 of an outlet of the main reaction zone is about 800 ℃. Quenching oil is injected into the quenching zone 4 to cool the pyrolysis gas to 350 ℃, and then the mixture enters a subsequent system for further separation.

Table 2 example 2 product distribution comparison of condensate direct pyrolysis with steam pyrolysis using a conventional tube furnace

Product distribution (wt%)	Direct pyrolysis	Conventional steam cracking
			Hydrogen gas	0.98	0.92
Methane	12.97	14.88
			Ethylene	34.10	32.11
Ethane (E)	2.86	3.80
			Propylene (PA)	17.11	16.06
Propane	0.38	0.46
			Mixed carbon four	11.23	9.64
Mixed carbon five	4.86	4.21
			Carbon six	15.51	17.92
Total up to	100.00	100.00

10.02 million tons of ethylene and 5.04 million tons of propylene can be produced annually by adopting the reactor in the example 1 under the process parameters. As can be seen from Table 2, when the condensate oil is cracked, the yield of ethylene and propylene is respectively improved by 6.2 percent and 6.5 percent by directly heating the hydrocarbon by using the reactor in the embodiment 1 compared with the traditional steam cracking technology, and the economic benefit is obvious.

Example 3:

a single reactor for producing 10 ten thousand tons of ethylene per year:

the reactor of the embodiment 1 is adopted to directly heat and crack crude oil to prepare low-carbon olefin. The crude oil specifications are shown in table 3:

table 3 specification table of crude oil used in example 3

Item	Data of
		Density (20 ℃ C.)/(kg/m) 3 )	860.4
Kinematic viscosity (40 ℃ C.)/(mm) 2 /s)	5.8
		Sulfur content/%)	0.031
Pour point/. Degree.C	30
		Carbon residue/%)	0.22
Characteristic factor K	11.8
		Carbon content/%)	85.37
Content of hydrogen/%)	12.45

The operation steps are as follows:

s1: starting the oxyhydrogen burner 1-1, introducing hydrogen and a mixture of water vapor and oxygen into the oxyhydrogen burner 1-1 respectively, combusting the hydrogen, and introducing the generated high-temperature water vapor into a combustion zone cylinder 1-3;

s2: the obtained high-temperature water vapor flows through a contraction conical body 2-1 and an equal-diameter short section 2-2 in sequence, and is mixed with cracking raw materials from a first raw material inlet 2-3 and a second raw material inlet 2-4 in sequence, part of the cracking raw materials are subjected to cracking reaction, then the materials enter an expansion conical body 3-1, are mixed with the cracking raw materials from a third raw material inlet 3-2 and are further reacted, reaction products enter a quenching zone 4, quenching oil with the temperature of 180 ℃ is sprayed in through a 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 high-temperature cracking gas to 350 ℃, the cracking reaction is stopped to obtain target products, and the target products enter a secondary cooling zone 5 to be further cooled. The temperature of the mixture at the exit 4-2 of the quench section is controlled by controlling the amount of quench oil injected.

In step S1, hydrogen flow rate: 2910kg/hr, oxygen flow: 20955kg/hr, steam flow: 77320kg/hr.

In the 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 cracking raw materials, and simultaneously with introducing atomization steam, the mass ratio of the atomization steam to the cracking raw materials is 0.3:1. the retention time of the material in the enlarged conical body 3-1 is 0.06s, and the material flow velocity at the equal-diameter short section 2-2 is 88m/s.

As shown in fig. 3, hydrogen flow rate: 2910kg/hr, oxygen flow: 20955kg/hr, steam flow: 77320kg/hr, mixing oxygen and water vapor, feeding into oxyhydrogen burner 1-1, mixing with hydrogen in oxyhydrogen burner 1-1, and burning to generate high temperature water vapor at 1300 deg.C. And (3) spraying crude oil into the mixing pre-reaction zone 2, wherein the flow rate of the crude oil is 48250kg/hr, the crude oil is mixed with high-temperature steam, the high-temperature steam directly transfers heat to the crude oil, the temperature of the crude oil is rapidly raised to 850-890 ℃, the crude oil is rapidly subjected to cracking reaction to produce cracked gas, and the temperature of the cracked gas at the position 3-3 of the outlet of the main reaction zone is about 790 ℃. The temperature of the quenching oil injected through the direct cooling medium inlet 4-3 is 195 ℃, the pyrolysis gas is fully mixed with the quenching oil in the quenching zone 4, the temperature after mixing is 350 ℃, and the temperature of the mixture at the outlet 4-2 of the quenching zone can be controlled by controlling the amount of the injected quenching oil. The mixture then enters a subsequent system for further separation.

Table 4 example 3 comparison of product distribution for direct thermal cracking of crude oil and steam cracking using a conventional tube furnace

Product distribution (wt%)	Direct pyrolysis	Conventional steam cracking
			Hydrogen gas	0.67	0.64
Methane	8.67	10.15
			Ethylene	25.91	24.35
Ethane (III)	2.36	2.98
			Propylene (PA)	15.06	14.12
Propane	0.34	0.38
			Mixed carbon four	11.28	10.24
Mixed carbon five	5.91	5.61
			Carbon six +	29.80	31.53
Is totaled	100.00	100.00

10.02 ten thousand tons of ethylene and 5.81 ten thousand tons of propylene can be produced annually by using the reactor in the example 1 under the process parameters. As can be seen from Table 4, when cracking crude oil, the yield of ethylene and propylene is respectively increased by 6.4% and 6.65% by directly heating the hydrocarbon in the reactor of example 1 compared with the conventional steam cracking technology, and the economic benefit is obvious.

Example 4:

reactor for annual production of 5 ten thousand tons of ethylene:

compared with the example 1, most of the reactors used in the example are the same, except that 1 indirect heat exchanger 4-6 is arranged in a heat exchange barrel 4-7 of a quenching zone 4 of the reactor in the example, as shown in fig. 2, an inlet 4-1 of the quenching zone is connected with an outlet 3-3 of a main reaction zone, the indirect heat exchanger 4-6 is a double-sleeve quenching heat exchanger, a double-sleeve structure is adopted, the diameter of the heat exchange tube is phi 51mm, the number of the heat exchange tubes is 198, cooling media are water, the cooling media enter from the indirect cooling media inlet 4-4, and a steam-water mixture is led out from the indirect cooling media outlet 4-5.

In this example, the typical naphtha is directly heated and cracked to prepare low-carbon olefins. The naphtha specifications are shown in Table 5.

Table 5 specification table for naphtha of example 4

Item	Naphtha fraction
		Relative density (20/4 ℃ C.)	0.69
ASTM distillation
		IBP	40℃
50vol％	85℃
		EBP	170℃
PONA wt％
		Alkane(s)	≥70
Wherein the normal alkane	≥30
		Olefins	≤1
Cycloalkanes	≤25
		Aromatic hydrocarbons	≤6

The operation steps are as follows:

s1: starting the oxyhydrogen burner 1-1, introducing hydrogen and a mixture of water vapor and oxygen into the oxyhydrogen burner 1-1 respectively, combusting the hydrogen, and introducing the generated high-temperature water vapor into a combustion zone cylinder 1-3;

s2: the obtained high-temperature water vapor sequentially flows through a contraction conical body 2-1 and an equal-diameter short joint 2-2, and is sequentially mixed with cracking raw materials from a first raw material inlet 2-3 and a second raw material inlet 2-4, a part of the cracking raw materials are subjected to cracking reaction, then the material enters an expansion conical body 3-1, is mixed with the cracking raw material from a third raw material inlet 3-2 and is further reacted, a reaction product enters a quenching zone 4, the temperature of the mixture is reduced to 375 ℃ after heat exchange, the reaction is terminated to obtain a target product, and then the mixture enters a subsequent secondary cooling zone 5 for further cooling.

In step S1, hydrogen flow rate: 1256kg/hr, oxygen flow: 9120kg/hr, steam flow: 30060kg/hr.

In the 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 cracking raw materials, and simultaneously with the introduction of atomizing water vapor, the mass ratio of the atomizing water vapor to the cracking raw materials is 0.2:1. the retention time of the material in the enlarged conical body 3-1 is 0.05s, and the material flow velocity at the equal-diameter short section 2-2 is 90m/s.

In the step S2, the cooling medium of the quenching zone 4 is water, the temperature of the water is 310 ℃, the pressure of the water is 120Mpa, and the steam-water mixture led out from the indirect cooling medium outlet 4-5 is cooled, wherein the mass ratio of the steam to the water is 1:9; the temperature of the mixture at the exit 4-2 of the quench section is 375 deg.c.

Wherein the hydrogen flow rate is as follows: 1256kg/hr, oxygen flow: 9120kg/hr, steam flow: 30060kg/hr, as shown in FIG. 4, oxygen and water vapor are mixed and fed into oxyhydrogen burner 1-1, and mixed with hydrogen gas in oxyhydrogen burner 1-1 for combustion to generate high temperature water vapor at 1400-1450 deg.C. Naphtha is sprayed into the mixing pre-reaction zone 2, the flow rate of the naphtha is 20440kg/hr, the naphtha and high-temperature steam are mixed through the mixing pre-reaction zone 2, the high-temperature steam directly transfers heat to the naphtha, the temperature of the naphtha is rapidly raised to 860-900 ℃, cracking reaction is rapidly carried out to generate pyrolysis gas, and the temperature of the pyrolysis gas at the position 3-3 of an outlet of the main reaction zone is about 810 ℃.

Then, the pyrolysis gas enters an indirect heat exchanger 4-6, after passing through the indirect heat exchanger 4-6, the waste heat of the pyrolysis gas is recovered for generating high-pressure steam, meanwhile, the pyrolysis gas is cooled to about 380 ℃, then the pyrolysis gas enters a secondary cooling area 5, the pyrolysis gas is cooled to 220 ℃ by injecting quenching oil through an oil quencher, and then the pyrolysis gas is sent to a subsequent system for further heat recovery and component separation.

The reactor of the embodiment can produce 5 ten thousand tons of ethylene and 2.53 ten thousand tons of propylene every year under the process parameters. As can be seen from Table 6, when naphtha is cracked, the yield of ethylene and propylene is respectively increased by 6.4% and 7.8% by directly heating the reactor of the present embodiment to crack hydrocarbons, compared with the conventional steam cracking technology, and the economic benefit is obvious.

Table 6 example 4 direct thermal cracking of naphtha and comparison of product distribution using conventional tube furnace steam cracking

Product distribution (wt%)	Direct pyrolysis	Conventional steam cracking
			Hydrogen gas	1.08	1.03
Methane	14.89	16.11
			Ethylene (CO) process	30.58	28.73
Ethane (III)	2.55	2.93
			Propylene (PA)	15.49	14.37
Propane	0.27	0.32
			Mixed carbon four	10.73	9.77
Mixed carbon five	3.95	3.61
			Carbon six	20.46	23.13
Is totaled	100.00	100.00

Example 5:

direct thermal cracking unit producing 20 million tons of ethylene annually:

as shown in fig. 5, the reactors of example 4 are used in parallel, and 5 reactors are used in one group, so that a cracking reaction unit with 20 ten thousand tons of annual output can be formed, wherein 4 reactors can be on-line, and 1 reactor is in a coke burning or standby state. For a device for producing 100 million tons of ethylene every year, the requirements of actual production can be met by adopting 5 cracking reaction units (equivalent to six traditional ethylene cracking furnaces), and the large-scale device for producing the low-carbon olefin by direct heating cracking is realized.

Example 6:

the reactors in example 3 are used in parallel, and 2 reactors are used in one group, so that a cracking reaction unit capable of producing 20 ten thousand tons of ethylene annually can be easily formed. For a 120 ten thousand ton ethylene device, the requirements of actual production can be met by adopting 7 cracking reaction units, and the large-scale production of the low-carbon olefin device by direct heating cracking is realized.

Example 7:

compared with the embodiment 1, most parts are the same, except that in the embodiment, the high-temperature resistant brick layer 1-2 on the inner wall of the combustion area cylinder 1-3 is changed into a water jacket structure, and circulating cooling water is introduced between jackets to achieve the effect of protecting the inner wall of the combustion area cylinder 1-3.

Example 8:

compared with the embodiment 1, most of the same except that in the embodiment, the ' 120-degree included angle formed by the central line of the flame sprayed by the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 and the circumferential tangent of the side wall of the combustion zone cylinder 1-3 when the oxyhydrogen burner 1-1 is in operation ' is changed into the ' 180-degree included angle formed by the central line of the flame sprayed by the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 when the oxyhydrogen burner 1-1 is in operation.

Example 9:

compared with the embodiment 1, most of them are the same, except that in this embodiment, "the included angle formed by the center line of the flame sprayed by the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 and the circumferential tangent of the side wall of the combustion zone cylinder 1-3 is 120 degrees" is changed into "the included angle formed by the center line of the flame sprayed by the oxyhydrogen burner 1-1 arranged on the side wall of the combustion zone cylinder 1-3 and the circumferential tangent of the side wall of the combustion zone cylinder 1-3 is 0 degrees" when the oxyhydrogen burner 1-1 is operated.

Example 10:

compared with the embodiment 1, the angle between the side wall of the equal-diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is changed into 100 degrees except that the included angle between the side wall of the equal-diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is 150 degrees.

Example 11:

compared with the embodiment 1, most of the parts are the same, except that in the embodiment, the included angle between the side wall of the equal-diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is changed into the included angle between the side wall of the equal-diameter short section 2-2 and the side wall of the enlarged conical body 3-1 is 170 degrees.

Example 12:

compared with the embodiment 1, the angle between the side wall of the convergent cone 2-1 and the side wall of the combustion zone cylinder 1-3 is changed to be 120 degrees in most parts except that the angle between the side wall of the convergent cone 2-1 and the side wall of the combustion zone cylinder 1-3 is changed to be 100 degrees in the embodiment.

Example 13:

compared with the embodiment 1, most parts are the same, except that in the embodiment, the included angle between the side wall of the contraction cone 2-1 and the side wall of the combustion zone cylinder 1-3 is changed to be 120 degrees, and the included angle between the side wall of the contraction cone 2-1 and the side wall of the combustion zone cylinder 1-3 is changed to be 170 degrees.

The embodiments described above are intended to facilitate the understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention according to the disclosure of the present invention.

Claims (10)

1. A reactor for preparing low-carbon olefin by cracking hydrocarbons through direct heating by a heat carrier is characterized by comprising:

combustion zone (1) for providing high temperature water vapor: the device comprises a combustion zone cylinder (1-3) with one end closed, wherein the combustion zone cylinder (1-3) is provided with an oxyhydrogen burner (1-1);

a mixing pre-reaction zone (2) for mixing the feedstock and high temperature steam located downstream of the combustion zone (1): the device comprises a contraction conical body (2-1) and an equal-diameter short section (2-2), wherein the flaring end of the contraction conical body (2-1) is connected with the unsealed end of a combustion zone cylinder body (1-3), the closing end of the contraction conical body (2-1) is connected with one end of the equal-diameter short section (2-2), the contraction conical 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) located downstream of the mixing pre-reaction zone (2): the pipe joint comprises an enlarged conical body (3-1), wherein the closing end of the enlarged conical body (3-1) is connected with the other end of the equal-diameter short joint (2-2), and the enlarged conical body (3-1) is provided with a third raw material inlet (3-2);

a quench zone (4) for stopping the cracking reaction, located downstream of said main reaction zone (3).

2. The reactor for preparing low-carbon olefin by hydrocarbon cracking through direct heating by heat carrier according to claim 1, characterized in that a plurality of oxyhydrogen burners (1-1) are provided, and a plurality of oxyhydrogen burners (1-1) are arranged on the side wall of the combustion zone cylinder (1-3) or on the central part of the closed end of the combustion zone cylinder (1-3) at equal intervals around the central axis of the combustion zone cylinder (1-3).

3. The reactor for preparing low-carbon olefin by hydrocarbon cracking through direct heating by heat carrier as claimed in claim 2, wherein when the oxyhydrogen burner (1-1) is arranged on the side wall of the combustion zone cylinder (1-3), the included angle formed by the center line of the flame sprayed from the oxyhydrogen burner (1-1) and the tangent of the circumference of the side wall of the combustion zone cylinder (1-3) is 0-180 °.

4. The reactor for preparing low carbon olefin by hydrocarbon cracking through direct heating by heat carrier of claim 2, characterized in that when the oxyhydrogen burner (1-1) is arranged at the central part of the closed end of the combustion zone cylinder (1-3), the center line of the flame emitted by the oxyhydrogen burner (1-1) is parallel to the central axis of the combustion zone cylinder (1-3).

5. The reactor for preparing the low-carbon olefin by the pyrolysis of the hydrocarbons directly heated by the heat carrier according to the claim 1, characterized in that the inner wall of the combustion zone cylinder (1-3) is further provided with a high-temperature resistant heat insulation material layer.

6. The reactor for preparing the low-carbon olefin by the hydrocarbon pyrolysis by directly heating a heat carrier according to claim 1, wherein the combustion zone cylinder (1-3) has a double-layer jacket structure, and a cooling medium is introduced into the jacket.

7. The reactor for preparing the low-carbon olefin by the direct heat hydrocarbon pyrolysis of the heat carrier according to the claim 1, characterized in that, the first raw material inlets (2-3) are provided with a plurality of first raw material inlets (2-3), and the plurality of first raw material inlets (2-3) are arranged on the side wall of the convergent cone (2-1) at equal intervals around the central axis of the convergent cone (2-1);

the second raw material inlets (2-4) are provided with a plurality of second raw material inlets, and the second raw material inlets (2-4) are arranged on the side wall of the constant-diameter short section (2-2) at equal intervals around the central axis of the constant-diameter short section (2-2);

the third raw material inlets (3-2) are provided with a plurality of third raw material inlets, and the third raw material inlets (3-2) are arranged on the side wall of the enlarged conical body (3-1) at equal intervals around the central axis of the enlarged conical body (3-1).

8. The reactor for preparing the low-carbon olefin by the hydrocarbon cracking through direct heating by the heat carrier as claimed in claim 1, wherein 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 conical 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).

9. The reactor for preparing the low-carbon olefin by the hydrocarbon pyrolysis by directly heating a heat carrier according to claim 1, wherein the included angle between the side wall of the constant diameter short section (2-2) and the side wall of the enlarged conical body (3-1) is 100-170 degrees.

10. The reactor for preparing the low-carbon olefin by the hydrocarbon pyrolysis through direct heat of the heat carrier according to claim 1, wherein the included angle between the side wall of the contraction cone (2-1) and the side wall of the combustion zone cylinder (1-3) is 100-170 degrees.

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