WO2023072196A1 - 裂解反应装置、裂解制备烯烃的方法及应用 - Google Patents

裂解反应装置、裂解制备烯烃的方法及应用 Download PDF

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WO2023072196A1
WO2023072196A1 PCT/CN2022/127962 CN2022127962W WO2023072196A1 WO 2023072196 A1 WO2023072196 A1 WO 2023072196A1 CN 2022127962 W CN2022127962 W CN 2022127962W WO 2023072196 A1 WO2023072196 A1 WO 2023072196A1
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section
cracking
lightening
water
reaction device
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PCT/CN2022/127962
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English (en)
French (fr)
Inventor
刘同举
王国清
张利军
周丛
杜志国
张兆斌
石莹
刘俊杰
蒋冰
巴海鹏
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中国石油化工股份有限公司
中国石油化工股份有限公司北京化工研究院
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Publication of WO2023072196A1 publication Critical patent/WO2023072196A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/18—Apparatus
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
    • C10G9/18—Apparatus
    • C10G9/20—Tube furnaces
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G9/34—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils by direct contact with inert preheated fluids, e.g. with molten metals or salts
    • C10G9/36—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils by direct contact with inert preheated fluids, e.g. with molten metals or salts with heated gases or vapours

Definitions

  • the invention relates to the field of cracking, in particular to a cracking reaction device, a method for cracking and preparing olefins and its application.
  • Low-carbon olefins usually mainly include ethylene, propylene, butene, butadiene and other unsaturated hydrocarbons and are organic chemical raw materials with high economic value.
  • organic chemical raw materials With the development of the economy, the demand for these organic chemical raw materials is increasing year by year.
  • naphtha has been used as the main raw material for the preparation of light olefins.
  • cheap associated gas from oilfields in the Middle East and shale gas in the United States have been widely used as ethylene raw materials, resulting in lower prices for ethylene-related products.
  • a cracking reactor In order to make full use of crude oil resources and increase the yield of low-carbon olefins, a cracking reactor is usually used to crack various hydrocarbon raw materials into olefins by steam cracking.
  • Commonly used pyrolysis reaction devices include a convection section and a radiation section.
  • Steam cracking has been used to crack various hydrocarbon feedstocks into olefins, preferably lower olefins such as ethylene, propylene, butenes and butadiene.
  • Conventional steam cracking employs a cracking furnace with two main sections: a convective section and a radiant section.
  • the hydrocarbon feedstock typically enters the convection section of the cracking furnace as a liquid, where it is heated and vaporized, typically by indirect contact with hot flue gases from the radiant section and by direct contact with steam.
  • the vaporized feedstock and steam mixture is then introduced into the radiant section where cracking occurs.
  • Products including olefins leave the cracking furnace for further downstream processing including quenching.
  • CN101583697A discloses a method for cracking raw materials containing synthetic oil.
  • the method includes mixing existing raw materials for ethylene production into crude oil, diluting the crude oil, improving the cracking performance of the crude oil, and increasing the conversion rate of olefins.
  • this method is limited by the existing sources of raw materials for ethylene production, and cannot effectively utilize a large amount of crude oil for the production of light olefins.
  • CN109651041A discloses a preparation method of light olefins, the method comprising the following steps: (1) contacting and separating heavy oil with supercritical carbon dioxide to obtain a light fluid phase containing light oil and carbon dioxide, and a heavy oil containing heavy oil a fluid phase; (2) separating the components of the light fluid phase containing light oil and carbon dioxide to obtain light oil and carbon dioxide; (3) subjecting the light oil to steam thermal cracking to obtain light olefins.
  • the method adopts carbon dioxide to treat the heavy oil, and the performance of the crude oil is improved to some extent, it still has the problem of short operation period of the cracking reaction device.
  • the utilization rate of the crude oil is low, the yield of low-carbon olefins is low, and the cracking reaction device is easy to coke, and the operation period is short.
  • the object of the present invention is to provide a cracking reaction device, a method for preparing olefins by cracking and an application thereof in order to overcome the technical problems of low utilization rate of crude oil, low yield of low-carbon olefins and short operation period of a cracking reaction device in the prior art.
  • Crude oil contains high molecular weight non-volatile components.
  • the inventors of the present invention have found that when these non-volatile components are preheated in the convection section of the conventional cracking reaction device, a small part is not gasified; the non-volatile components that are not gasified are entrained with the mixed gas flow To the radiant section, it is easy to cause coking deposition in the radiant section, or even block the radiant section, which will affect the yield of cracked products and shorten the operating cycle of the device. For this reason, the present invention converts at least part of the heavy component macromolecules in the crude oil into smaller molecules by lightening the crude oil in water, thereby providing more suitable raw materials for steam thermal cracking.
  • the water required for lightening can also play the role of diluting steam in the cracking section.
  • the utilization rate of crude oil and the yield of low-carbon olefins can be further improved, and the coking of the cracking reaction device can be reduced, and the running time of the cracking reaction device can be extended.
  • the first aspect of the present invention provides a cracking reaction device, which includes a preheating section, a lightening section, a decompression gasification section and a cracking section connected in sequence.
  • the lightening section includes a lightening vessel, preferably a lightening tank.
  • the preheating section includes a heating vessel or a heat exchanger.
  • the reduced-pressure gasification section includes a reduced-pressure gasification vessel.
  • the cracking section includes a cracker.
  • the cracking reaction device includes one or more reaction tubes, and each reaction tube includes the preheating section, lightening section, decompression gasification section and cracking section connected in sequence.
  • the arrangement of the reaction tubes can be horizontal, vertical or hanging.
  • the cracking reaction device further includes a pressurizing section before the preheating section, and/or a quenching section after the cracking section.
  • a decompression device is disposed between the lightening section and the decompression gasification section to reduce the pressure of the materials entering the decompression gasification section.
  • the decompression device is a decompression valve, a pressure control valve or a throttling element.
  • the temperatures of the preheating section, the lightening section, the vacuum gasification section and the cracking section are increased sequentially.
  • the temperatures of the preheating section, lightening section, vacuum gasification section and cracking section are 150-250°C, 350-450°C, 550-650°C and 770-880°C in sequence.
  • the preheating section is a double-layer tube or a tube with more layers.
  • spiral protrusions are provided in the inner tube and/or on the outer wall of the double-layer tube or the multi-layer tube and/or on the tube wall of the middle layer and/or on the inner wall of the outer tube.
  • the ratio of the inner diameter of the inner tube to the inner diameter of the outer tube of the double-layer tube is 0.1-0.9, preferably 0.4-0.6.
  • the helical directions of the helical protrusions in adjacent tube layers are opposite.
  • the helical aspect ratio of the helical protrusion is 0.1-20, preferably 1-10.
  • the diameter ratio of the spiral protrusion is 0.01-0.5, preferably 0.02-0.1.
  • the pressurizing section is provided with a pressurizing device; preferably, the pressurizing device is a pump.
  • the volume ratio of the preheating section, lightening section, vacuum gasification section and cracking section is 0.1-10:0.1-1000:0.1-10:1, preferably 0.1-0.5:1 -300:0.1-0.5:1.
  • the second aspect of the present invention provides a cracking reaction device, the cracking reaction device comprises: a cracking raw material inlet, a cracking product outlet, a pressurized section connected in sequence, a preheating section, a lightening section, a decompression gasification section, A cracking section and a quenching section, the feed inlet of the cracking raw material is arranged in the preheating section, and the outlet of the cracked product is arranged in the quenching section, wherein the preheating section, the lightening section, the The decompression gasification section, the cracking section, and the quenching section are respectively equipped with temperature control devices to control the temperature of each section during use.
  • the pressure device reduces the pressure of the material entering the decompression gasification section, the structure of the preheating section is a double-layer tube, and the inner wall of the inner tube and/or the inner wall of the outer tube of the double-layer tube is provided with a spiral convex rise.
  • the ratio of the inner diameter of the inner tube to the inner diameter of the outer tube of the double-layer tube is 0.1-0.9, preferably 0.4-0.6.
  • the helical protrusions on the inner wall of the inner tube are opposite to the helical direction of the helical protrusions on the inner wall of the outer tube.
  • the helical aspect ratio of the helical protrusions on the inner wall of the inner tube is 0.1-20, preferably 1-10.
  • the helical aspect ratio of the helical protrusions on the inner wall of the outer tube is 0.1-20, preferably 1-10.
  • the diameter ratio of the spiral protrusions on the inner wall of the inner tube is 0.01-0.5, preferably 0.02-0.1. In some embodiments, the diameter ratio of the spiral protrusions on the inner wall of the outer tube is 0.01-0.5, preferably 0.02-0.1.
  • the volume ratio of the preheating section, the lightening section, the decompression gasification section, the quenching section and the cracking section is 0.1-10:0.1-1000:0.1- 10:0.1-10:1, preferably 0.1-0.5:1-300:0.1-0.5:0.1-0.5:1.
  • the pressure reducing device is a pressure reducing valve, a pressure control valve or a throttling element.
  • the pressurizing section is provided with a pressurizing device, preferably, the pressurizing device is a pump.
  • the cleavage reaction device is composed of one or more reaction tubes. In some embodiments, the arrangement of the reaction tubes is horizontal, vertical or suspended.
  • the third aspect of the present invention provides a method for preparing olefins by cracking, characterized in that the method comprises the following steps:
  • the temperature of the first heating, the second heating, the third heating and cracking is increased sequentially; preferably, from step (2) to step (5), the temperature increase between adjacent steps is between 100- 250°C, preferably in the range of 150-250°C.
  • the temperatures of the first heating, the second heating, the third heating and the cracking are sequentially 150-250°C, 350-450°C, 550-650°C and 770-880°C.
  • the weight ratio of the water to the cracking raw material is 0.3-10.5, preferably 0.5-5.
  • the cracking feedstock is crude oil.
  • the pressures of the cracking raw material and water are respectively: 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the conditions for the first heating include: the temperature is lower than 350°C, preferably 150-250°C; the pressure is 10-40MPa, preferably 15-30MPa, more preferably 21 -30MPa.
  • the lightening reaction is carried out in supercritical water or under conditions close to supercritical water; preferably, the conditions of the lightening reaction include: the temperature is 350-450 °C, the pressure is 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • step (4) the decompression reduces the pressure of the lightening reaction mixture to 0.01-0.5MPa, preferably 0.1-0.3MPa; and the third heating makes the The temperature of the mixture after the lightening reaction is raised to 550-650°C.
  • the conditions of the cracking reaction include: a temperature of 770-880° C., preferably 780-820° C., and a pressure of 0.01-0.5 MPa, preferably 0.2-0.3 MPa.
  • the residence time of the material can be 0.1-0.5 seconds.
  • the method further includes: (6) cooling the cleavage product obtained after the cleavage reaction.
  • the cooling is such that the temperature of the cracked product is not higher than 550° C., and the pressure is 0.01-0.5 MPa, preferably 0.2-0.3 MPa.
  • the method can be carried out in the cleavage reaction device of the present application.
  • a fourth aspect of the present invention provides a method for preparing olefins by cracking, the method comprising:
  • the temperatures of the first heating, the second heating, the third heating and the cracking reaction are sequentially increased and the increment is in the range of 100-250°C, preferably 150-250°C.
  • the weight ratio of the water to the cracking raw material can be 0.3-10.5, preferably 0.5-5.
  • the cracking raw material is at least one of crude oil, residual oil, and heavy hydrocarbons obtained by processing crude oil.
  • the pressure of the cracking raw material and water is 10-40 MPa, preferably 21-30 MPa.
  • the conditions of the first heating include: the temperature is lower than 350°C, preferably 150-250°C; the pressure is 10-40MPa, preferably 21-30MPa.
  • the lightening reaction conditions include: a temperature of 350-450° C., and a pressure of 10-40 MPa, preferably 21-30 MPa.
  • step (4) the decompression reduces the pressure of the lightening reaction mixture to 0.01-0.5MPa, preferably 0.1-0.3MPa; the third heating makes the The temperature of the mixture after the lightening reaction rose to 550-650°C.
  • the conditions of the cracking reaction include: temperature is 770-880°C, preferably 780-820°C, pressure is 0.01-0.5MPa, preferably 0.2-0.3MPa, residence time 0.1-0.5 seconds.
  • step (6) within 0.1 second, the cooling is such that the temperature of the cracked product is not higher than 550° C., and the pressure is 0.01-0.5 MPa, preferably 0.2-0.3 MPa.
  • the method can be carried out in the cleavage reaction device of the present application.
  • the fifth aspect of the present invention provides the application of the above-mentioned cracking reaction device in cracking and preparing olefins.
  • the cracking reaction device and/or the cracking method provided by the invention can effectively improve the cracking efficiency of crude oil and increase the yield of olefins, thereby reducing operating costs, reducing coking and clogging of the cracking device, and prolonging the running time of the cracking reaction device.
  • Fig. 1 is the schematic diagram of the pyrolysis reaction device of an embodiment of the present invention.
  • Fig. 2 is a structural perspective view of a preheating section of a cracking reaction device according to an embodiment of the present invention.
  • Fig. 3 is a structural perspective view of a preheating section of a cracking reaction device according to another embodiment of the present invention.
  • references to “one embodiment” or “some embodiments” means that a described feature, structure, or characteristic in connection with said embodiment is included in at least one embodiment. In one or more embodiments, the features, structures or characteristics may be combined in any suitable manner.
  • One aspect of the present invention provides a cracking reaction device, which includes a preheating section, a lightening section, a decompression gasification section and a cracking section connected in sequence.
  • cracking has a commonly known meaning in the art and refers to the decomposition of hydrocarbons into smaller hydrocarbons containing fewer carbon atoms due to the breaking of carbon-carbon bonds.
  • the "cracking" in the present application is steam cracking;
  • the "steam cracking” has a commonly known meaning in the art, and refers to a thermal cracking reaction occurring in the presence of steam.
  • the cracking reaction device of the present application includes a preheating section, a lightening section, a decompression gasification section and a cracking section which are connected in sequence.
  • the processed stream passes through the preheating section, the lightening section, the decompression gasification section and the cracking section in sequence.
  • the cracking reaction device may further include a pressurizing section before the preheating section.
  • the pressurization section the cracking raw material and water are pressurized to the required pressure.
  • the cracking raw material and water are pressurized to 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the pressure may be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, 21MPa, 22MPa, 23MPa, 24MPa, 25MPa, 26MPa, 27MPa, 28MPa, 29MPa, 30MPa, 31MPa, 32MPa, 33MPa, 34MPa, 35MPa, 36MPa, 37MPa, 38MPa or 39MPa.
  • the pressurized section includes or is, for example, a pipe for feeding the cracking feedstock and water into the preheating section.
  • the pressurization section is provided with a pressurization device.
  • a pressurization device Various pressurization devices generally known in the art can be used.
  • said pressurizing device is a pump.
  • the preheating section is used for preheating materials, including the cracking raw materials and water.
  • the materials to be preheated such as cracking raw materials and water
  • a desired temperature such as a temperature not exceeding 350°C.
  • the preheating section heats the material to a temperature of, for example, 150-250°C.
  • the preheating section heats the material to 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C or 340°C.
  • the preheating section includes a heating vessel or a heat exchanger. After the pressurized cracking raw material and water are fed into the heating vessel, the cracking raw material and water are heated to a desired temperature in the heating vessel. In the case of using a heat exchanger, the cracking feedstock and water are heated to a desired temperature by heat exchange.
  • the preheating section is tubular. In some embodiments, the preheating section is a double layer tube or a tube with more layers. In some embodiments, the preheating section comprises or is a section of a tubular reactor (ie, the preheating section of the tubular reactor).
  • the pressure of the materials is 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the cracking raw material can be pressurized and preheated separately, and the water can be pressurized and preheated separately, and then the pressurized and preheated cracking raw material and the pressurized and preheated water are mixed together.
  • the cleavage feedstock alone can be pressurized and the water alone can be pressurized; the pressurized cleavage feedstock and pressurized water are then mixed together to obtain a mixture; and the resulting mixture is heated to the desired preheat temperature.
  • the cracking feedstock and water can be mixed and the mixture pressurized and preheated.
  • the cracking feedstock and water can be added to a vessel to obtain a mixture, and the mixture in the vessel can be pressurized and preheated.
  • the warm-up section is the lightweight section.
  • Materials such as cracking raw materials and water, are sent to the lightening section after being preheated in the preheating section.
  • the cracking raw material and water are further heated, for example to a temperature of 300-540°C, preferably 300-500°C, more preferably 350-450°C.
  • cracking raw materials and water are heated to 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C °C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C or 530°C.
  • the pressure of cracking raw materials and water is 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the critical temperature of water is about 374° C. and the critical pressure of water is about 22.1 megapascals (MPa).
  • Supercritical water is water having a temperature equal to or higher than the critical temperature of water and a pressure equal to or higher than the critical pressure of water.
  • water is in a near-critical or supercritical state.
  • the cracking raw material such as crude oil
  • the cracking raw material reacts in the presence of near-critical or supercritical water, so that at least part of the heavy component macromolecules in the cracking raw material are converted into smaller molecules to obtain lightening mixture.
  • the lightening section includes a lightening vessel such as a lightening tank.
  • the lightening section comprises or is a section of a tubular reactor.
  • multiple lightening reactors can be connected in series or in parallel.
  • part of the lightening reactor discharges reactants to the vacuum gasification section
  • part of the lightening reactor introduces cracking raw materials and water, and Some lightening reactors are undergoing lightening reactions. This can keep the continuous and stable operation of the subsequent sections of the cracking reaction device.
  • the pressurized and preheated cracking raw material and water enter the lightening reactor, and react for 1-120 minutes under the conditions of 350-450° C. and 21-30 MPa to obtain a lightening mixture.
  • all of the obtained lightened mixture enters the vacuum gasification section; or after separating the solid residue and optionally part of the water, it enters the vacuum gasification section.
  • the lightening section is the decompression gasification section.
  • the lightened mixture obtained from the lightening section is sent to the vacuum gasification section.
  • the lightened mixture obtained after lightening is sent to the decompression gasification section for decompression gasification and heating to obtain a completely or substantially completely gasified steam-containing mixture (gas mixture).
  • the decompression reduces the pressure of the lightened mixture to 0.01-0.5 MPa, preferably 0.1-0.4 MPa.
  • the pressure of the lightened mixture can be reduced to 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa or 0.45MPa.
  • the heating in the reduced-pressure gasification section raises the temperature of the steam-containing mixture to, for example, 550-700°C, preferably 550-650°C.
  • the heating in the vacuum gasification section allows the temperature of the steam-containing mixture to rise to 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C , 650°C, 660°C, 670°C, 680°C or 690°C.
  • the reduced-pressure gasification section includes a reduced-pressure gasification vessel.
  • the depressurized gasification section comprises or is a section of a tubular reactor.
  • a decompression device is disposed between the lightening section and the decompression gasification section to reduce the pressure of the materials entering the decompression gasification section.
  • Any pressure relief device capable of reducing pressure may be used.
  • the decompression device is a decompression valve, a pressure control valve or a throttling element.
  • the decompression gasification section is followed by a cracking section.
  • the steam-containing mixture (gas mixture) obtained from the vacuum gasification section is sent to the cracking section.
  • the material is subjected to steam cracking treatment.
  • the cracking section the material is heated to the cracking temperature; preferably, the material is heated to a temperature of 710-900°C, preferably 770-880°C, more preferably 780-820°C; in the cracking section, the pressure is 0.01-0.5 MPa, preferably 0.1-0.4 MPa.
  • the material is heated to 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C or 890°C.
  • the pressure in the cracking section, can be 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa MPa, 0.4MPa or 0.45MPa.
  • the residence time of the material in the cracking section is relatively short.
  • a person skilled in the art can suitably select the desired residence time.
  • the residence time of the material in the cracking section is 0.1-0.5 seconds.
  • the residence time of the material in the cracking section can be 0.1 second, 0.2 second, 0.3 second, 0.4 second or 0.5 second.
  • the cracking section includes a cracker.
  • the cracker may be a cracker generally known in the art, such as a steam cracker.
  • the cracking section comprises or is part of a tubular reactor.
  • the cracking reaction device may further include a quenching section after the cracking section. Quenching the lysate after lysis is known in the art.
  • the quenching section is used to rapidly cool the cracked product obtained by cracking, so as to prevent the cracked product from staying at high temperature for too long and cause coking.
  • the quenching section can use equipment generally known in the art.
  • the temperature of the cracked product is cooled to not higher than 550°C, preferably to 450-550°C; the pressure is 0.01-0.5MPa, preferably 0.1-0.4MPa.
  • the cracking reaction device of the present application may include one or more reaction tubes and each reaction tube includes the preheating section, lightening section, vacuum gasification section and cracking section connected in sequence. That is to say, the preheating section, the lightening section, the decompression gasification section and the cracking section respectively form a part of the reaction tube and are sequentially connected to form the whole reaction tube.
  • each of the preheating section, the lightening section, the vacuum gasification section and the cracking section may be tubular.
  • each of the preheating section, the lightening section, the vacuum gasification section and the cracking section is a part of the reaction tube and has the same tube diameter.
  • each of the preheating section, lightening section, vacuum gasification section and cracking section is a part of the reaction tube, but their tube diameters may be the same or different from each other.
  • the length and diameter of each section can be reasonably selected and set, for example based on flow rate, volume and residence time Wait to make a selection.
  • the arrangement of the reaction tubes can be horizontal, vertical or suspended, or any other arrangement that can be adopted in this field.
  • the temperatures of the preheating section, the lightening section, the vacuum gasification section and the cracking section are sequentially increased.
  • the temperature increase between two adjacent sections of the preheating section, the lightening section, the vacuum gasification section and the cracking section is within the range of 100-250°C, preferably 150-250°C.
  • the temperatures of the preheating section, lightening section, vacuum gasification section and cracking section are 150-250°C, 350-450°C, 550-650°C and 770-880°C respectively.
  • heating can be performed by means of heat exchange.
  • heating may be performed, for example, by electrical heating or burning a combustible gas.
  • the type of combustible gas is not limited; various combustible gases known in the art can be used.
  • the preheating section, the lightening section, the vacuum gasification section and the cracking section are respectively equipped with temperature control devices to control the temperature of each section.
  • the preheating section includes or is a double-layer pipe or a multi-layer pipe.
  • the preheating section is a double-layer pipe or a pipe with more layers, the cracking raw material and water can be arranged in different pipes or pipe layers.
  • spiral protrusions are provided on the innermost tube and/or on the outer wall of the double-layer tube or more layers of tubes and/or on the innermost tube and/or on the outer wall of the tube in the middle layer and/or on the inner wall of the outermost tube. rise.
  • the helical directions of the helical protrusions in adjacent tube layers are opposite.
  • the helical protrusions on the inner wall of the inner tube are in a clockwise direction
  • the helical protrusions on the inner wall of the outer tube are in a counterclockwise direction; and vice versa.
  • the preheating section When the preheating section is a tube with more than two layers, the preheating section may be a tube with three, four, five, six layers, etc.
  • the innermost tube space is referred to as the first tube layer, and is called the first tube layer, the second tube layer, the third tube layer, the fourth tube layer, etc. from the inside to the outside.
  • the cracking raw material and water enter into different tube layers of the preheating section respectively.
  • water can be sent into the inner tube (the first tube layer), and the cracking raw material can be sent into the outer tube (the second tube layer).
  • the cracking raw material can be sent into the first and third tube layers, and the water can be sent into the second tube layer (ie, the middle tube layer).
  • the second tube layer ie, the middle tube layer
  • water is not sent into the outermost tube layer.
  • the helical protrusions are disposed on the inner side (inner surface) of the outer tube wall of each tube layer.
  • the preheating section can be heated externally.
  • water is fed into the inner tube (1st tube layer) and the cracked raw material is fed into the outer layer (2nd tube layer), so that the sequence of heat transfer is Outer pipe wall, pyrolysis raw material, inner pipe wall and water.
  • the pyrolysis raw material and water generate opposite swirls under the action of the spiral protrusions, which thins the stagnant layer near the tube wall and greatly enhances the mass transfer and heat transfer in the tube.
  • the cracking raw material with the opposite swirl is in full contact with water, which greatly accelerates the speed of the lightening reaction.
  • the thickness of each tube layer of the double-layered tube or a higher-layered tube may be appropriately set.
  • the thickness of each tube layer can be appropriately set according to the amount and flow rate of the cracked raw material and water passing through the preheating section.
  • the ratio of the inner diameter of the inner tube to the inner diameter of the outer tube of the double-layer tube is 0.1-0.9, preferably 0.4-0.6.
  • the ratio of the inner diameter of the inner tube to the inner diameter of the outer tube of the double-layer tube may be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9.
  • the helical height-to-diameter ratio of the helical protrusion (the ratio of the height of a single turn of the helix to the diameter of the helix) is 0.1-20, preferably 1-10.
  • the aspect ratio may be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 , 14, 15, 16, 17, 18 or 19.
  • the diameter ratio of the spiral protrusion (for the innermost tube, is the ratio of the height of the spiral protrusion to the inner diameter of the tube; for other tube layers, it is the ratio of the height of the spiral protrusion to the inner diameter of the outer layer of the tube layer.
  • the ratio of the difference between the diameter and the outer diameter of the inner tube) is 0.01-0.5, preferably 0.02-0.1.
  • the convex diameter ratio can be 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.3 or 0.4 .
  • the cross-section of the spiral protrusion can take any commonly known shape, such as rectangle, square, triangle, trapezoid, semicircle, semiellipse and so on.
  • the helical protrusion height is defined as the height from the tube wall to the highest point of the cross-section of the helical protrusion.
  • the volume ratio of the preheating section, lightening section, vacuum gasification section and cracking section is 0.1-10:0.1-1000:0.1-10:1, preferably 0.1-7:1 -300:0.1-7:1, preferably 0.1-5:1-300:0.1-7:1, preferably 0.1-0.5:1-300:0.1-0.5:1.
  • the cracking reaction device includes reaction tubes and each reaction tube includes the preheating section, the lightening section, the decompression gasification section and the cracking section that are connected in sequence
  • the tube length and the cracking section of each section can be set. / or diameter to adjust volume.
  • the present invention provides a cracking reaction device, which comprises: cracking raw material inlet, cracking product outlet, sequentially connected pressurized section, preheating section, lightening section, decompression gasification section, A cracking section and a quenching section, the feed inlet of the cracking raw material is arranged in the preheating section, and the outlet of the cracked product is arranged in the quenching section, wherein the preheating section, the lightening section, the The decompression gasification section, the cracking section, and the quenching section are respectively equipped with temperature control devices to control the temperature of each section during use.
  • the pressure device reduces the pressure of the material entering the decompression gasification section;
  • the structure of the preheating section is a double-layer pipe, and the inner wall of the inner pipe and/or the inner wall of the outer pipe of the double-layer pipe are provided with spiral convex rise.
  • Figure 2 shows a preheating section that can be used in this application, which is a double-layer pipe.
  • the double-layer pipe includes an inner pipe 10 and an outer pipe 11 .
  • the ratio of the inner diameter of the inner tube 10 to the inner diameter of the outer tube 11 may be 0.1-0.9, preferably 0.4-0.6.
  • Spiral protrusions are respectively arranged on the inner wall of the inner tube and the inner wall of the outer tube.
  • the helical protrusions on the inner wall of the inner tube are opposite to the helical direction of the helical protrusions on the inner wall of the outer tube.
  • the helical height-to-diameter ratio of the helical protrusions on the inner wall of the inner tube (the ratio of the height of a single turn of the helix to the diameter of the helix) is 0.1-20, preferably 1-10.
  • the helical height-to-diameter ratio (ratio of the height of a single turn of the helix to the helix diameter) of the helical protrusions on the inner wall of the outer tube is 0.1-20, preferably 1-10.
  • the diameter ratio of the spiral protrusions on the inner wall of the inner tube (the ratio of the height of the protrusion to the inner diameter of the tube) is 0.01-0.5, preferably 0.02-0.1.
  • the diameter ratio of the spiral protrusions on the inner wall of the outer tube (the ratio of the height of the protrusion to the difference between the inner diameter of the outer tube and the outer diameter of the inner tube) is 0.01-0.5, preferably 0.02-0.1.
  • Figure 3 shows a preheating section that can be used in this application, which is a three-layer pipe.
  • the inner side of each layer of the tube wall of the three-layer tube has spiral protrusions.
  • the cracking raw material and water can enter into different pipe layers of the preheating section respectively.
  • the cracking raw materials and water can enter between the inner layer pipe and the inner and outer layer pipes of the preheating section respectively.
  • water flows through the inner tube, and the pyrolysis raw material flows between the inner and outer tubes. The order of heat transfer is the outer tube, the cracking raw material, the inner tube, and the water.
  • the corrosion of the outer tube wall of the reaction tube is greatly reduced.
  • the pyrolysis raw material and water will generate opposite swirl flows under the action of the spiral protrusions, which will thin the stagnant layer near the tube wall and greatly enhance the mass transfer and heat transfer in the tube.
  • the cracking raw material with the opposite swirl is in full contact with water, which greatly accelerates the speed of the lightening reaction.
  • the volume ratio of the preheating section, the lightening section, the decompression gasification section, the quenching section and the cracking section is 0.1-10:0.1-1000 :0.1-10:0.1-10:1, preferably 0.1-0.5:1-300:0.1-0.5:0.1-0.5:1.
  • the specific form of the decompression device is not limited, as long as the purpose of decompression can be achieved.
  • the decompression device may be a decompression valve, a pressure control valve or a throttling element.
  • the pressurizing section is provided with a pressurizing device.
  • said pressurizing device is a pump.
  • the cleavage reaction device includes one or more reaction tubes.
  • each reaction tube is provided with a sequentially connected pressurization section, preheating section, lightening section, decompression gasification section, cracking section and optionally a quenching section.
  • the arrangement of the reaction tubes can be horizontal, vertical or hanging.
  • the heating method of the cracking reaction device is not limited. Heating can be done, for example, by electric heating or by burning combustible gases in bottom burners.
  • the present invention does not specifically limit the type of combustible gas, and various available combustible gases known in the art can be used.
  • the preheating section, the lightening section, the decompression gasification section, and the cracking section can be respectively equipped with temperature control devices to control the temperature of each section to increase sequentially during use.
  • the temperature increase is preferably between 150- 250°C range.
  • the preheating section, the lightening section, the decompression gasification section, the cracking section, and the quenching section are respectively equipped with temperature control devices to control the temperature of each section to 150 °C in turn. -250°C, 350-450°C, 550-650°C, 770-880°C, 450-550°C.
  • the product obtained in a certain stage can be separated, and a part of the product can enter the next stage to continue the subsequent process, which also belongs to the protection scope of the present invention.
  • each reaction tube includes the preheating section, lightening section, decompression gasification section and cracking section connected in sequence, in any of the above There is no separation of product between the two stages; that is, the product of the upstream stage is entirely sent to the stage downstream of that stage.
  • a cracking reaction device comprises: feed inlet 3, cracking product outlet 9, pressurization section (this embodiment realizes pressurization by pressurization equipment, promptly water pump 1 and crude oil pump 2 in Fig. 1), preheating section 4.
  • the preheating section 4, the lightening section 5, the decompression gasification section 6, the cracking section 7, and the quenching section 8 are respectively equipped with temperature control devices to control the temperature during use. temperature of each section.
  • a decompression device is disposed between the lightening section and the decompression gasification section to reduce the pressure of the lightened mixture entering the decompression gasification section.
  • the preheating section 4, the lightening section 5, the decompression gasification section 6, the cracking section 7 and the quenching section 8 form a tube reactor.
  • Another aspect of the present invention provides a method for preparing olefins by cracking, characterized in that the method comprises the following steps:
  • Another aspect of the present invention provides a method for preparing olefins by cracking, the method comprising:
  • the temperatures of the first heating, the second heating, the third heating and the cracking are sequentially increased.
  • the temperature increase between adjacent steps is in the range of 150-250°C.
  • the temperatures of the first heating, the second heating, the third heating and the cracking are sequentially increased and the increment is in the range of 150-250°C, preferably in the range of 150-250°C. In some embodiments, preferably, the temperatures of the first heating, the second heating, the third heating and the cracking are respectively 150-250°C, 350-450°C, 550-650°C and 770-880°C.
  • the weight ratio of the water to the cracking raw material is 0.3-10.5, preferably 0.5-5.
  • the weight ratio of the water and the cracking raw material can be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1 , 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.5, 4, or 4.5.
  • the positive reaction of cleavage is the increase of the number of moles. Reducing the pressure and adding water (water vapor under the reaction conditions) can reduce the partial pressure of hydrocarbons, which is beneficial to promote the positive reaction and increase the conversion rate.
  • the cracking raw material may include at least one of crude oil, residual oil and heavy hydrocarbons obtained from crude oil processing.
  • the resid may include atmospheric resid and vacuum resid.
  • the cracking raw material is crude oil.
  • any water that can generally be used in petrochemical processes can be used.
  • deionized water, recycled water, regenerated water, etc. can be used.
  • the cracking raw material and water are pressurized to a desired pressure.
  • the cracking raw material and water are pressurized to 10-40 MPa, preferably 15-30 MPa, more preferably 21-30 MPa.
  • the pressure may be 15MPa, 16MPa, 17MPa, 18MPa, 19MPa, 20MPa, 21MPa, 22MPa, 23MPa, 24MPa, 25MPa, 26MPa, 27MPa, 28MPa, 29MPa, 30MPa, 31MPa, 32MPa, 33MPa, 34MPa, 35MPa, 36MPa, 37MPa, 38MPa or 39MPa.
  • the pressurizing step can be carried out in the pipeline for transporting cracking raw material and water.
  • said pressurization can be carried out in the pipes that carry the cracking feedstock and water to the preheating step.
  • the pressurization can be performed by pressurization equipment known in the art.
  • said pressurizing device is a pump.
  • step (2) After pressurizing the cracking raw material and water, they are preheated, that is, a preheating step (step (2)).
  • the preheating step is used for preheating materials, including the cracking raw materials and water.
  • the materials to be preheated such as cracking raw materials and water
  • a desired temperature such as a temperature not exceeding 350°C.
  • the preheating step heats the material to a temperature of, for example, 150-250°C.
  • the preheating section heats the material to 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C or 340°C.
  • the preheating step includes using a heating vessel and/or a heat exchanger.
  • a heating vessel After feeding the pressurized cracking raw material and water into the heating vessel, the cracking raw material and water are heated to a desired temperature in the heating vessel.
  • the cracking feedstock and water are heated to a desired temperature by heat exchange.
  • the preheating step may be a section of the tubular reactor (ie, the preheating section of the tubular reactor).
  • the pressure of the material is 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa. In some embodiments, the pressure in the preheating step can be the same as the pressure in the pressurizing step.
  • the cracking raw material can be pressurized and preheated separately, and the water can be pressurized and preheated separately, and then the pressurized and preheated cracking raw material and the pressurized and preheated water are mixed together.
  • the cleavage feedstock alone can be pressurized and the water alone can be pressurized; the pressurized cleavage feedstock and pressurized water are then mixed together to obtain a mixture; and the resulting mixture is heated to the desired preheat temperature.
  • the cracking feedstock and water can be mixed and the mixture pressurized and preheated.
  • the cracking feedstock and water can be added to a vessel to obtain a mixture, and the mixture in the vessel can be pressurized and preheated.
  • steps (1) and (2) can be combined into one step.
  • the pressure of the cracking raw material and water is 10-40 MPa, preferably 15-30 MPa, more preferably 21-30 MPa.
  • cracking raw material and water can be respectively pressurized to 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the cracking raw material and water are mixed and pressurized to 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the purpose of pressurization is to keep water and crude oil in a liquid state in the lightening reaction; also to achieve the near-critical or supercritical state of water; in this state, mass transfer, heat transfer and reaction are all strengthened, and the light-weight The reaction speed is fast, and it is not easy to coke.
  • the first heating conditions include: heating the temperature to no more than 350°C, preferably 150-250°C; pressure of 10-40MPa, preferably 15-30MPa, more Preferably it is 21-30MPa.
  • the preheating step is followed by a lightweight treatment step.
  • lightening refers to treating materials at or near the temperature and pressure of supercritical water.
  • the conditions of the lightening treatment may include: a temperature of 350-450°C, a pressure of 10-40MPa, preferably 15- 30MPa, more preferably 21-30MPa.
  • the time of lightening treatment can be reasonably selected to obtain the desired lightening treatment product.
  • the treatment time of the lightening step may be 0.2 minutes to 240 minutes, preferably 0.5 minutes to 60 minutes, more preferably 1-10 minutes.
  • the cracked feedstock and water are further heated, for example to a temperature of 300-540°C, preferably 300-500°C, more preferably 350-450°C.
  • cracking raw materials and water are heated to 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C °C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C or 530°C.
  • the cracking raw material such as crude oil
  • water react so that at least part of the heavy component macromolecules in the cracking raw material Convert smaller molecules to be more suitable as feedstock for steam thermal cracking.
  • the water required for lightening can also serve as a dilution steam during the cracking stage.
  • the lightening reaction mixture contains steam and lightening reaction products of cracking raw materials.
  • the cracked feedstock and water from the preheating step are further heated, for example to a temperature of 350-450°C.
  • the pressure of the cracking raw material and water is 10-40MPa, preferably 15-30MPa, more preferably 21-30MPa.
  • the pressure in the lightening step may be the same as the pressure in the preheating step and/or the pressure in the pressurizing step.
  • the cracking raw material (such as crude oil) reacts in the presence of near-critical or supercritical water, so that at least part of the heavy component macromolecules in the cracking raw material are converted into smaller molecules to obtain light liquefied mixture.
  • the lightening treatment step is performed in a lightening vessel such as a lightening reactor.
  • the lightening treatment step is carried out in a tubular reactor (ie, the lightening section of the tubular reactor).
  • multiple lightening reactors can be connected in series or in parallel.
  • part of the lightening reactor discharges reactants to the vacuum gasification section
  • part of the lightening reactor introduces cracking raw materials and water
  • Some lightening reactors are performing lightening reactions to maintain the continuous and stable operation of the method of this application.
  • the pressurized and preheated cracking raw material and water are reacted at 350-450° C. and 21-30 MPa for 1-120 minutes in the lightening treatment step to obtain a lightening mixture.
  • the method of the present application also includes a decompression gasification step (step (4)) after the lightening treatment to obtain a gaseous mixture.
  • step (4) the decompression makes the pressure drop of the mixture after the lightening reaction be 0.01-0.5MPa, preferably 0.1-0.4MPa .
  • the pressure of the mixture can be reduced to 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa MPa, 0.4MPa or 0.45MPa.
  • the temperature does not decrease.
  • the third heating is performed such that the temperature of the lightening-reacted mixture is further increased, preferably to 550- 650°C.
  • the heating in the reduced-pressure gasification section raises the temperature of the mixture to, for example, 550-700°C, preferably 550-650°C.
  • the heating in the decompression gasification section allows the temperature of the mixture to rise to 560°C, 570°C, 580°C, 590°C, 600°C, 610°C, 620°C, 630°C, 640°C, 650°C , 660°C, 670°C, 680°C or 690°C.
  • the reduced-pressure gasification step is performed in a reduced-pressure gasification vessel.
  • the reduced-pressure gasification step is performed in a tubular reactor (ie, the reduced-pressure gasification section of the tube reactor).
  • the mixture (gas mixture) obtained by the decompression gasification is subjected to steam cracking (step (5), cracking step).
  • the cleavage reaction is a reaction system with strong endothermic, increased mole number, and a large number of side reactions. Therefore, high temperature, low pressure, and short residence time are favorable process conditions for the cracking reaction to produce olefins.
  • the cracking reaction conditions include: a temperature of 770-880°C, preferably 780-820°C, and a pressure of 0.01-0.5MPa, preferably 0.2- 0.3MPa, residence time 0.1-0.5 seconds.
  • the material is heated to the cracking temperature; preferably, the material is heated to a temperature of 710-900°C, preferably 770-880°C, more preferably 780-820°C.
  • the pressure is 0.01-0.5 MPa, preferably 0.1-0.4 MPa.
  • the material is heated to 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C or 890°C.
  • the pressure in the cracking section, can be 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa, 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa MPa, 0.4MPa or 0.45MPa.
  • the residence time of the material in the cracking section can be 0.1 second, 0.2 second, 0.3 second, 0.4 second or 0.5 second.
  • the lysing step is performed in a lyser.
  • the cracker may be a cracker generally known in the art, such as a steam cracker.
  • the cleavage step is performed in a tubular reactor (ie, the cleavage section of the tube reactor).
  • the method of the present application may further comprise a cooling (quenching) step after the cracking step. Cooling (quenching) the cleavage product after cleavage is known in the art.
  • the cooling step (step (6)) within 0.1 second, the cooling makes the temperature of the cracked product not higher than 550°C (for example, cooling to 450-550°C), and the pressure is 0.01-0.5MPa, preferably 0.2-0.3MPa.
  • the quenching step can be performed in quenching equipment generally known in the art.
  • the method of the present application can be implemented in the above-mentioned cleavage reaction device of the present application.
  • the pressurizing section is used to pressurize the cracking raw material and water.
  • the preheating section is used for first heating the pressurized cracking raw material and water.
  • the lightening section is used for second heating the cracked raw material and water after the first heating, and makes the cracked raw material undergo a lightening reaction in the presence of supercritical water or near-critical water.
  • the decompression gasification section is used for decompressing the lightening reaction mixture and performing third heating to obtain a third heated mixture of lightening reaction products containing steam and cracking raw materials.
  • the cracking section is used for cracking the mixture in the presence of steam.
  • the quenching section is used to rapidly cool the cracked products after the cracking reaction, so as to prevent the reaction raw materials from staying at high temperature for too long and cause coking.
  • the (2) to (5) steps (ie preheating step, lightening treatment step, reduced pressure gasification step and cracking step) of the method of the present application include the reaction It is carried out in the pyrolysis reaction device of the tube, wherein the reaction tube includes a preheating section, a lightening section, a decompression gasification section and a cracking section connected in sequence to respectively implement the preheating step, the lightening step, the decompression gasification step and lysis step.
  • the cleavage reaction device described above in this application can be used in the method of this application. Accordingly, features described in the apparatus section of the present application may also apply to the method of the present application as applicable; and vice versa.
  • the temperature or pressure range given for each stage or step is the temperature or pressure that is expected to be achieved in this stage or step.
  • the realization of the temperature or pressure value requires a process.
  • the preheating step heats the material to a temperature of 200°C
  • the temperature of the material will be lower than 200°C at the beginning of the heating and will increase to 200°C as the heating proceeds.
  • the preheating step is carried out in a tubular reactor (tube preheating section)
  • the material is lower than 200 °C at the inlet of the tube preheating section, and as the material flows in the tube, its temperature rises and reaches 200 °C °C.
  • the material of the inner and outer pipe layers is gradually heated in the preheating section, and the average temperature at the outlet of the preheating section reaches 200 °C.
  • the third aspect of the present invention provides the application of the above-mentioned cracking reaction device of the present application in cracking and preparing olefins.
  • the cracking reaction device of the present application can be used for cracking heavy raw materials such as crude oil, preferably steam cracking.
  • the pressures are all absolute pressures.
  • the low-carbon olefins prepared by cracking include ethylene, propylene and butadiene.
  • compositions of the crude oils used in the following examples and comparative examples are shown in Table 1.
  • the composition is determined according to ASTM D5307, a simulated distillation method of analysis. Measurements were performed using an Agilent 7890 gas chromatograph.
  • Crude oil and water are lightened in supercritical or near-supercritical water in a tubular lightening reaction device and a stirred reactor respectively.
  • the results are shown in Table A and Table B.
  • the reaction device and conditions are as follows: Lightened crude oil a (tubular lightening reaction device composed of the preheating section and lightening section of Example 1 in Table 2; water-to-oil ratio 1.5; preheating section temperature 250 ° C pressure 27MPa ; lightening section temperature 440°C pressure 27MPa, residence time 15min); lightening crude oil b (reaction device is the same as lightening crude oil a; water-oil ratio 1.5; preheating section temperature 250°C pressure 24MPa; lightening section temperature 430°C, pressure 24MPa, residence time 15min); light crude oil c (in a stirred tank type lightening reactor with a volume of 110mL, water volume 28g, water-oil ratio 1.5, 430°C, 32MPa, stirring speed 600r/min, Reaction
  • the light component is the sum of the components with a boiling point below 220°C
  • the heavy component is the sum of the components with a boiling point above 500°C.
  • the cracking reaction device comprises: a water pump, a crude oil pump, a feed inlet, a preheating section, a lightening section, a decompression gasification section, a cracking section, a quenching section, and a cracking product outlet, which are connected in sequence.
  • the preheating section, lightening section, decompression gasification section, cracking section and quenching section are arranged as tube reactors.
  • the structure of the preheating section is a double-layer tube, and the inner wall of the double-layer tube is provided with spiral protrusions in opposite directions (the cross-sectional shape is rectangular and the width is 1mm).
  • the water pump and the crude oil pump are used to pressurize the cracking raw material and water;
  • the preheating section is used to first heat the pressurized cracking raw material and water;
  • the cracking raw material and water enter the preheating section through the feed port , the water goes through the inner tube of the preheating section, and the cracking raw material goes between the inner and outer tubes of the preheating section;
  • a lightening reaction occurs in the presence of water;
  • the decompression gasification section is used to decompress the mixture after the lightening reaction first and then perform the third heating to obtain the third heated light containing steam and cracking raw materials.
  • the cracking section is used for cracking the third heated mixture in the presence of steam;
  • the quenching section is used for cooling the cracked product after the cracking reaction, and the cracked reaction product It is drawn out from the cracked product outlet on the quenching section.
  • the cracking section is a tube with an inner diameter of 10 mm and a length of 1 meter.
  • Example 1-6 except that the inner diameter of the lightweight section in Example 6 is 32 mm, the inner diameters of the other sections are all 10 mm.
  • the temperature of the quenching section refers to the temperature of the cracked product after cooling within 0.1 second.
  • the operating cycle of the pyrolysis reaction device is defined as the time from the start of the pyrolysis reaction device to the time when the pyrolysis reaction device has to be coked and stopped due to coking.
  • Ethylene yield (wt%) weight of ethylene obtained from cracking/weight of crude oil feed ⁇ 100%
  • Propylene yield (wt%) weight of propylene obtained from cracking/weight of crude oil feed ⁇ 100%
  • Butadiene yield (wt%) weight of butadiene obtained from cracking/weight of crude oil feed ⁇ 100%
  • Triene total yield (wt%) ethylene yield + propylene yield + butadiene yield
  • embodiment 1-6 adopts the technical scheme of the present invention, the yield of gained ethylene, propylene and butadiene is higher, and the total yield of triene is also higher, and equipment running time long. Comparative example 1 does not adopt the technical scheme of the present invention, the yield of gained ethylene, propylene and butadiene is lower, and the total yield of trienes is also lower, and the equipment operation period only maintains 12 hours, and the reaction tube is just because of coking too much. Severe and had to burn.

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Abstract

裂解反应装置、裂解制备烯烃的方法及应用。裂解反应装置包括依次相连的预热段、轻质化段、减压气化段和裂解段。裂解制备烯烃的方法包括将裂解原料和水进行加压；将加压后的裂解原料和水进行第一加热；将第一加热后的裂解原料和水进行第二加热并在水的存在下轻质化裂解原料得到轻质化的混合物；将轻质化的混合物进行减压气化并进行第三加热，获得第三加热后的混合物；和在蒸汽的存在下，在裂解温度下裂解第三加热后的混合物以得到包含烯烃的裂解产物。裂解反应装置和/或裂解方法能够有效提高原油裂解效率，提高烯烃收率，从而降低运行成本，且能够减少裂解装置的结焦和堵塞，延长裂解反应装置的运行时间。

Description

裂解反应装置、裂解制备烯烃的方法及应用 技术领域
本发明涉及裂解领域，具体地涉及裂解反应装置、裂解制备烯烃的方法及应用。
背景技术
低碳烯烃通常主要包括乙烯、丙烯、丁烯、丁二烯等不饱和碳氢化合物并且是具有高经济价值的有机化工原料。随着经济的发展，这些有机化工原料的需求量逐年增大。长期以来，石脑油被用作制备低碳烯烃的主要原料。但近年来，廉价的中东油田伴生气以及美国页岩气作为乙烯原料被大量使用，造成乙烯相关产品价格降低。为了应对市场竞争的冲击，拓展乙烯裂解反应装置的原料来源，降低原料成本，成为传统乙烯企业降本增效的有效手段。所以，将重质烃，特别是未经加工处理的原油，作为裂解反应装置原料来生产低碳烯烃，有利于降低烯烃生产的原料成本和能源消耗，以快速适应市场裂解原料的供需变化。
为了充分利用原油资源，提高低碳烯烃的收率，通常利用裂解反应装置采用蒸汽裂化将各种烃类原料裂化成烯烃。常用的裂解反应装置包括对流段和辐射段。
蒸汽裂解已经被用于将各种烃原料裂解为烯烃，优选低碳烯烃例如乙烯、丙烯、丁烯和丁二烯。常规蒸汽裂解采用具有两个主要区段的裂解炉：对流段和辐射段。烃原料一般作为液体进入裂解炉的对流段，其中一般通过与来自辐射段的热烟道气间接接触和与蒸汽直接接触而加热和汽化。然后将汽化的原料和蒸汽混合物引入其中发生裂解的辐射段。包括烯烃的产物离开裂解炉用于包括急冷的进一步下游加工。
CN101583697A公开了一种用于裂解包含合成油的原料的方法，该方法包括在原油中混入现有的乙烯生产原料，对原油进行稀释，改善原油的裂解性能，提高烯烃的转化率。但该方法受现有乙烯生产原料来源的限制，不能有效利用大量原油进行低碳烯烃的生产。
CN109651041A公开了一种低碳烯烃的制备方法，该方法包括以下步骤：(1)将重质油与超临界二氧化碳进行接触及分离，得到含有轻油和 二氧化碳的轻流体相，以及含有重油的重流体相；(2)将所述含有轻油和二氧化碳的轻流体相进行组分分离，得到轻油，以及二氧化碳；(3)将所述轻油进行蒸汽热裂解，得到低碳烯烃。该方法尽管采用二氧化碳对重质油进行处理，原油的性能得到一定的改善，但是仍然存在裂解反应装置运行周期短的问题。
采用上述方法对原油进行裂解，原油利用率低、低碳烯烃收率低，并且裂解反应装置易结焦，运行周期短。
发明内容
本发明的目的是为了克服现有技术存在的原油利用率低、低碳烯烃收率低并且裂解反应装置运行周期短的技术问题，提供裂解反应装置、裂解制备烯烃的方法及应用。
原油中包含高分子量非挥发性组分。本发明的发明人发现，这些非挥发性组分在常规的裂解反应装置的对流段进行预热时，有小部分未被气化；未被气化的非挥发性组分随着混合气流夹带到辐射段，容易造成辐射段的结焦沉积，甚至堵塞辐射段，影响裂解产品的收率并缩短装置运行周期。为此，本发明通过使原油在水中发生轻质化反应，把原油中的至少部分重组分大分子转化较小分子，从而提供更适宜用于蒸汽热裂解的原料。而且，轻质化所需的水在裂解段还能起到稀释蒸汽的作用。另外，通过将轻质化反应后的产物先进行减压并加热接着再进行裂解反应，能够进一步提高原油利用率和低碳烯烃收率，并且减少裂解反应装置结焦，延长裂解反应装置的运行时间。
本发明第一方面提供一种裂解反应装置，所述裂解反应装置包括依次相连的预热段、轻质化段、减压气化段和裂解段。
在一些实施方式中，所述轻质化段包括轻质化容器，优选轻质化釜。
在一些实施方式中，所述预热段包括加热容器或换热器。在一些实施方式中，所述减压气化段包括减压气化容器。在一些实施方式中，所述裂解段包括裂解器。
在一些实施方式中，所述裂解反应装置包括一根或多根反应管并且每根反应管包括依次相连的所述预热段、轻质化段、减压气化段和裂解段。所述反应管的排列方式可以为水平式、垂直式或悬挂式。
在一些实施方式中，所述裂解反应装置还包括在预热段之前的加压段，和/或在所述裂解段之后的急冷段。
在一些实施方式中，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低。优选地，所述减压器件为减压阀、压力控制阀或节流元件。
在一些实施方式中，所述预热段、轻质化段、减压气化段和裂解段的温度是顺序提高的。优选地，所述预热段、轻质化段、减压气化段和裂解段的温度依次为150-250℃、350-450℃、550-650℃和770-880℃。
在一些实施方式中，所述预热段为双层管或更多层的管。在一些实施方式中，所述双层管或更多层的管的内层管内和/或外壁上和/或中间层的管壁上和/或外层管内壁上设有螺旋凸起。
在一些实施方式中，所述双层管的内层管内直径与外层管内直径之比为0.1-0.9，优选为0.4-0.6。在一些实施方式中，相邻管层内的螺旋凸起的螺旋方向相反。在一些实施方式中，所述螺旋凸起的螺旋高径比为0.1-20，优选为1-10。在一些实施方式中，所述螺旋凸起的凸径比为0.01-0.5，优选为0.02-0.1。
在一些实施方式中，所述加压段设置有加压设备；优选地，所述加压设备为泵。
在一些实施方式中，所述预热段、轻质化段、减压气化段和裂解段的体积比为0.1-10∶0.1-1000∶0.1-10∶1，优选为0.1-0.5∶1-300∶0.1-0.5∶1。
本发明第二方面提供一种裂解反应装置，该裂解反应装置包括：裂解原料进料口、裂解产物出口、依次相连的加压段、预热段、轻质化段、减压气化段、裂解段和急冷段，所述裂解原料进料口设置在所述预热段，所述裂解产物出口设置在所述急冷段，其中，所述预热段、所述轻质化段、所述减压气化段、所述裂解段、所述急冷段分别配置有控温装置以在使用时控制各段的温度，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低，所述预热段结构为双层管，且所述双层管的内层管内壁和/或外层管内壁设有螺旋凸起。
在一些实施方式中，所述双层管的内层管内直径与外层管内直径的比为0.1-0.9，优选为0.4-0.6。在一些实施方式中，所述内层管内壁 的螺旋凸起与所述外层管内壁的螺旋凸起的螺旋方向相反。在一些实施方式中，所述内层管内壁的螺旋凸起的螺旋高径比为0.1-20，优选为1-10。在一些实施方式中，所述外层管内壁的螺旋凸起的螺旋高径比为0.1-20，优选为1-10。在一些实施方式中，所述内层管内壁的螺旋凸起的凸径比为0.01-0.5，优选为0.02-0.1。在一些实施方式中，所述外层管内壁的螺旋凸起的凸径比为0.01-0.5，优选为0.02-0.1。
在一些实施方式中，所述预热段、所述轻质化段、所述减压气化段、所述急冷段和所述裂解段的体积比为0.1-10∶0.1-1000∶0.1-10∶0.1-10∶1，优选为0.1-0.5∶1-300∶0.1-0.5∶0.1-0.5∶1。
在一些实施方式中，所述减压器件为减压阀、压力控制阀或节流元件。在一些实施方式中，所述加压段设置有加压设备，优选地，所述加压设备为泵。
在一些实施方式中，所述裂解反应装置的组成结构为一根或多根反应管。在一些实施方式中，所述反应管的排列方式为水平式、垂直式或悬挂式。
本发明第三方面提供一种裂解制备烯烃的方法，其特征在于，该方法包括以下步骤：
(1)将裂解原料和水进行加压；
(2)将加压后的裂解原料和水进行第一加热；
(3)将第一加热后的裂解原料和水进行第二加热并在水的存在下轻质化裂解原料得到轻质化的混合物(其包含裂解原料的轻质化反应产物)；
(4)将轻质化的混合物进行减压气化并进行第三加热，获得第三加热后的混合物(气态)；和
(5)在蒸汽的存在下，在裂解温度裂解第三加热后的混合物以得到包含烯烃的裂解产物。
在一些实施方式中，所述第一加热、第二加热、第三加热和裂解的温度依次提高；优选地，从步骤(2)到步骤(5)，相邻步骤之间温度增幅在100-250℃、优选150-250℃范围内。在一些实施方式中，所述第一加热、第二加热、第三加热和裂解的温度依次为150-250℃、350-450℃、550-650℃和770-880℃。
在一些实施方式中，步骤(1)中，所述水和裂解原料的重量比为 0.3-10.5，优选为0.5-5。在一些实施方式中，所述裂解原料为原油。
在一些实施方式中，步骤(1)中，加压后，裂解原料和水的压力分别为：10-40MPa，优选为15-30MPa，更优选为21-30MPa。在一些实施方式中，步骤(2)中，所述第一加热的条件包括：温度低于350℃，优选为150-250℃；压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。在一些实施方式中，步骤(3)中，所述轻质化反应在超临界水或者接近超临界水的条件下进行；优选地，所述轻质化反应的条件包括：温度为350-450℃，压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。在一些实施方式中，步骤(4)中，所述减压使得所述轻质化反应后的混合物的压力降低至0.01-0.5MPa，优选为0.1-0.3MPa；和所述第三加热使得所述轻质化反应后的混合物的温度升至550-650℃。在一些实施方式中，步骤(5)中，所述裂解反应的条件包括：温度为770-880℃，优选为780-820℃，压力为0.01-0.5MPa，优选为0.2-0.3MPa。在步骤(5)中，物料的停留时间可以为0.1-0.5秒。
在一些实施方式中，所述方法还包括：(6)冷却裂解反应后得到的裂解产物。优选地，步骤(6)中，在0.1秒内，所述冷却使得裂解产品的温度不高于550℃，和压力为0.01-0.5MPa，优选为0.2-0.3MPa。
在一些实施方式中，所述方法可以在本申请中的裂解反应装置中进行。
本发明第四方面提供一种裂解制备烯烃的方法，该方法包括：
(1)将裂解原料和水进行加压；
(2)将加压后的裂解原料和水进行第一加热；
(3)第一加热后的裂解原料和水进行第二加热，并使得裂解原料在水的存在下发生轻质化反应；
(4)将轻质化反应后的混合物先进行减压再进行第三加热，获得第三加热后的含蒸汽和裂解原料的轻质化反应产物的混合物；
(5)在蒸汽的存在下，使所述裂解原料的轻质化反应产物发生裂解反应；
(6)将裂解反应后的裂解产品冷却。
在一些实施方式中，所述第一加热、第二加热、第三加热和裂解反应的温度依次提高且增幅在100-250℃、优选150-250℃范围内。在一些实施方式中，步骤(1)中，所述水和裂解原料的重量比可以为 0.3-10.5，优选为0.5-5。在一些实施方式中，所述裂解原料为原油、渣油和原油经加工得到的重质烃中的至少一种。
在一些实施方式中，步骤(1)中，加压后，裂解原料和水的压力为：10-40MPa，优选为21-30MPa。在一些实施方式中，步骤(2)中，所述第一加热的条件包括：温度低于350℃，优选为150-250℃；压力为10-40MPa，优选为21-30MPa。在一些实施方式中，步骤(3)中，所述轻质化反应的条件包括：温度为350-450℃，压力为10-40MPa，优选为21-30MPa。在一些实施方式中，步骤(4)中，所述减压使得所述轻质化反应后的混合物的压力降低至0.01-0.5MPa，优选为0.1-0.3MPa；所述第三加热使得所述轻质化反应后的混合物的温度升至550-650℃。在一些实施方式中，步骤(5)中，所述裂解反应的条件包括：温度为770-880℃，优选为780-820℃，压力为0.01-0.5MPa，优选为0.2-0.3MPa，停留时间0.1-0.5秒。在一些实施方式中，步骤(6)中，在0.1秒内，所述冷却使得裂解产品的温度不高于550℃，压力为0.01-0.5MPa，优选为0.2-0.3MPa。
在一些实施方式中，所述方法可以在本申请的裂解反应装置中进行。
本发明第五方面提供上述裂解反应装置在裂解制备烯烃中的应用。
本发明提供的裂解反应装置和/或裂解方法能够有效提高原油裂解效率，提高烯烃收率，从而降低运行成本，且能够减少裂解装置的结焦和堵塞，延长裂解反应装置的运行时间。
附图说明
图1是本发明一种实施方式的裂解反应装置的示意图；和
图2是本发明一种实施方式的裂解反应装置预热段的结构透视图。
图3是本发明另一种实施方式的裂解反应装置预热段的结构透视图。
如本领域技术人员知晓的那样，所述附图仅用于说明本申请的示例性实施方案，不一定是按照比例绘制的。
附图标记说明
1水泵、2原油泵、3裂解原料进料口、4预热段、5轻质化段、6减压气化段、7裂解段、8急冷段、9裂解产物出口、10内层管、 11外层管、12外层管内壁螺旋凸起、13内层管内壁螺旋凸起。
具体实施方式
在本文中所披露的范围的端点和任何值都不限于该精确的范围或值，这些范围或值应当理解为包含接近这些范围或值的值。对于数值范围来说，各个范围的端点值之间、各个范围的端点值和单独的点值之间，以及单独的点值之间可以彼此组合而得到一个或多个新的数值范围，这些数值范围应被视为在本文中具体公开。
在本说明书中，提及“一个实施方案”或“一些实施方案”是指与所述实施方案有关所描述的特征、结构或特性包括在至少一个实施方案中。在一个或多个实施方案中，这些特征、结构或特性能够以任何适合的方式进行组合。
本说明书中的单独实施方案可互相组合，但不包括违背自然规律和本领域技术人员基于其专业知识而因此排除的组合。
本发明的一方面提供一种裂解反应装置，所述裂解反应装置包括依次相连的预热段、轻质化段、减压气化段和裂解段。
本文中使用的“裂解”具有本领域中通常已知的含义，是指由于碳碳键的断裂而将烃分解为含有更少碳原子的较小的烃。优选地，本申请中的“裂解”是蒸汽裂解；所述“蒸汽裂解”具有本领域中通常已知的含义，是指在蒸汽存在下发生热裂解反应。
本申请的裂解反应装置包括依次相连的预热段、轻质化段、减压气化段和裂解段。根据一些实施方案，在所述裂解反应装置中，被处理的物流依次通过预热段、轻质化段、减压气化段和裂解段。
在一些实施方式中，所述裂解反应装置还可以包括在预热段之前的加压段。在加压段中，将裂解原料和水加压到所需的压力。在加压段加压后，裂解原料和水加压到10-40MPa，优选15-30MPa，更优选21-30MPa。根据一些实施方式，所述压力可以为15MPa、16MPa、17MPa、18MPa、19MPa、20MPa、21MPa、22MPa、23MPa、24MPa、25MPa、26MPa、27MPa、28MPa、29MPa、30MPa、31MPa、32MPa、33MPa、34MPa、35MPa、36MPa、37MPa、38MPa或39MPa。
在一些实施方式中，所述加压段包括或是例如将裂解原料和水送入预热段的管道。在一些实施方式中，所述加压段设置有加压设备。 可以使用本领域中通常已知的各种加压设备。优选地，所述加压设备为泵。
在对裂解原料和水进行加压后，将它们送入预热段。
所述预热段用于对物料，包括所述裂解原料和水，进行预热。在预热段中，将待预热的物料，例如裂解原料和水，加热到期望的温度，例如不超过350℃的温度。在一些实施方式中，所述预热段将物料加热至例如150-250℃的温度。例如，所述预热段将物料加热至150℃、160℃、170℃、180℃、190℃、200℃、210℃、220℃、230℃、240℃、250℃、260℃、270℃、280℃、290℃、300℃、310℃、320℃、330℃或340℃。
在一些实施方式中，所述预热段包括加热容器或换热器。在把加压的裂解原料和水送入加热容器后，在加热容器中将裂解原料和水加热到期望的温度。在使用换热器的情况下，通过热交换将裂解原料和水加热到期望的温度。在一些实施方式中，所述预热段是管式的。在一些实施方式中，所述预热段是双层管或更多层的管。在一些实施方式中，所述预热段包括或是管式反应器的一段(即管式反应器的预热段)。
在预热段中，物料(裂解原料和水)的压力为10-40MPa，优选15-30MPa，更优选21-30MPa。
在本发明中，裂解原料可以单独进行加压和预热，并且水可以单独进行加压和预热，然后将加压和预热的裂解原料和加压和预热的水混合在一起。或者，裂解原料可以单独进行加压并且水可以单独进行加压；然后将加压的裂解原料和加压的水混合在一起得到混合物；并将得到的混合物加热到期望的预热温度。或者，可以将裂解原料和水混合，然后将混合物加压并预热。例如，可以将裂解原料和水加入容器中得到混合物，然后对容器中的混合物进行加压并预热。
预热段之后是轻质化段。物料，例如裂解原料和水，在预热段中进行预热后被送入轻质化段中。
在轻质化段中，裂解原料和水被进一步加热，例如加热到300-540℃、优选300-500℃、更优选350-450℃的温度。例如，在轻质化段中，裂解原料和水被加热到310℃、320℃、330℃、340℃、350℃、360℃、370℃、380℃、390℃、400℃、410℃、420℃、430℃、440℃、450℃、460℃、470℃、480℃、490℃、500℃、510℃、520℃或530℃。
在轻质化段中，裂解原料和水的压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。
如本领域中已知的那样，水的临界温度为约374℃以及水的临界压力为约22.1兆帕(MPa)。超临界水为温度等于或高于水的临界温度并且压力等于或高于水的临界压力的水。在本申请的轻质化段中，水处于近临界或超临界状态。在本申请的轻质化段中，裂解原料(例如原油)在近临界或超临界水的存在下发生反应，使得裂解原料中的至少部分重组分大分子转化为较小分子，得到轻质化的混合物。
在一些实施方式中，所述轻质化段包括轻质化容器例如轻质化釜。或者，所述轻质化段包含或是管式反应器的一段。
在一些实施方式中，轻质化反应釜可以为多台串联或并联，在部分轻质化反应釜排出反应物至减压气化段时，部分轻质化反应釜引入裂解原料和水，以及部分轻质化反应釜在进行轻质化反应。这可以保持裂解反应装置后续各段连续稳定运行。
在一些实施方式中，加压和预热后的裂解原料和水进入轻质化反应釜，在350-450℃和21-30MPa的条件下，反应1-120min，得到轻质化的混合物。
在一些实施方式中，得到的轻质化的混合物全部进入减压气化段；或者分离出固体残渣和任选地部分水后进入减压气化段。
轻质化段之后是减压气化段。从轻质化段得到的轻质化的混合物被送入减压气化段中。轻质化后得到的轻质化的混合物被送入减压气化段进行减压气化并进行加热，获得完全或基本完全气化的含蒸汽的混合物(气态混合物)。
在一些实施方式中，所述减压使得所述轻质化的混合物的压力降低至0.01-0.5MPa，优选为0.1-0.4MPa。例如，所述轻质化的混合物的压力可以降低至0.02MPa、0.03MPa、0.04MPa、0.05MPa、0.06MPa、0.07MPa、0.08MPa、0.09MPa、0.1MPa、0.15MPa、0.2MPa、0.25MPa、0.3MPa、0.35MPa、0.4MPa或0.45MPa。减压气化段中的所述加热使得所述含蒸汽的混合物的温度升至例如550-700℃，优选550-650℃。例如，减压气化段中的所述加热使得所述含蒸汽的混合物的温度可以升至560℃、570℃、580℃、590℃、600℃、610℃、620℃、630℃、640℃、650℃、660℃、670℃、680℃或690℃。
在一些实施方式中，所述减压气化段包括减压气化容器。或者，所述减压气化段包含或是管式反应器的一段。
在一些实施方式中，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低。可以使用任何能够降低压力的减压器件。优选地，所述减压器件为减压阀、压力控制阀或节流元件。
所述减压气化段之后是裂解段。从减压气化段得到的含蒸汽的混合物(气态混合物)被送入裂解段。在裂解段中对物料进行蒸汽裂解处理。在裂解段中，物料被加热到裂解温度；优选地，物料被加热到710-900℃、优选770-880℃、更优选为780-820℃的温度；在裂解段中，压力为0.01-0.5MPa，优选为0.1-0.4MPa。例如，在裂解段中，物料被加热到720℃、730℃、740℃、750℃、760℃、770℃、780℃、790℃、800℃、810℃、820℃、830℃、840℃、850℃、860℃、870℃、880℃或890℃。例如，在裂解段中，压力可以为0.02MPa、0.03MPa、0.04MPa、0.05MPa、0.06MPa、0.07MPa、0.08MPa、0.09MPa、0.1MPa、0.15MPa、0.2MPa、0.25MPa、0.3MPa、0.35MPa、0.4MPa或0.45MPa。
如本领域中已知的那样，物料在裂解段中的停留时间较短。本领域技术人员可以合适地选择所需要的停留时间。优选地，物料在裂解段中的停留时间为0.1-0.5秒。例如，物料在裂解段中的停留时间可以为0.1秒、0.2秒、0.3秒、0.4秒或0.5秒。
在一些实施方式中，所述裂解段包括裂解器。所述裂解器可以是本领域中通常已知的裂解器，例如蒸汽裂解器。在一些实施方式中，所述裂解段包含或是管式反应器的一段。
在一些实施方式中，所述裂解反应装置还可以包括在所述裂解段之后的急冷段。在裂解后对裂解产物进行急冷是本领域中已知的。所述急冷段用于将裂解得到的裂解产物迅速冷却，防止裂解产物在高温下停留时间过长导致结焦。所述急冷段可以使用本领域中通常已知的设备。在一些实施方式中，在本申请的急冷段内，在例如0.1秒内，使裂解产物的温度冷却到不高于550℃，优选地冷却到450-550℃；压力为0.01-0.5MPa，优选为0.1-0.4MPa。
优选地，本申请的所述裂解反应装置可以包括一根或多根反应管并且每根反应管包括依次相连的所述预热段、轻质化段、减压气化段 和裂解段。即所述预热段、轻质化段、减压气化段和裂解段各自形成反应管的一部分并顺序连接组成整个反应管。在这样的实施方式中，所述预热段、轻质化段、减压气化段和裂解段可以各自都是管式的。
在一些实施方式中，所述预热段、轻质化段、减压气化段和裂解段各自是反应管的一部分并且各自具有相同的管径。可选地，所述预热段、轻质化段、减压气化段和裂解段各自是反应管的一部分，但是它们的管径可以彼此相同或不同。
对于包括依次相连的所述预热段、轻质化段、减压气化段和裂解段的反应管，可以合理地选择和设定各段的长度和直径，例如基于流量、容积和停留时间等等进行选择。
在本申请中，所述反应管的排列方式可以为水平式、垂直式或悬挂式，或本领域中可以采用的任何其他排列方式。
优选地，在本申请中，所述预热段、轻质化段、减压气化段和裂解段的温度是顺序提高的。优选地，所述预热段、轻质化段、减压气化段和裂解段的相邻两段之间的温度增幅在100-250℃、优选150-250℃的范围内。例如，优选地，所述预热段、轻质化段、减压气化段和裂解段的温度分别为150-250℃、350-450℃、550-650℃和770-880℃。
本申请中，对所述裂解反应装置的加热方式不做限定。例如，可以通过换热方式来进行加热。可选地，例如，可以通过电加热或燃烧可燃气体进行加热。本申请中，对可燃气体的种类不做限定；可以使用本领域中已知的各种可燃气体。在一些实施方式中，所述预热段、轻质化段、减压气化段和裂解段分别配置有控温装置以控制各段的温度。
在一些实施方式中，优选地，所述预热段包括或为双层管或更多层的管。在预热段为双层管或更多层的管的情况下，可以将裂解原料和水设置在不同的管或管层中。
优选地，所述双层管或更多层的管的最内层管内和/或外壁上和/或中间层的管的和/或外壁上和/或最外层管内壁上设有螺旋凸起。
在一些实施方式中，优选地，相邻管层内的螺旋凸起的螺旋方向相反。例如，对于双层管而言，如果内层管内壁上的螺旋凸起为顺时针方向，则外层管内壁上的螺旋凸起为逆时针方向；反之亦然。
当预热段为超过两层的管时，预热段可以是三层、四层、五层、 六层等等的管。在本申请中，将最内的管的管内空间称为第1管层，并从内向外依次称为第1管层、第2管层、第3管层、第4管层等等。在本发明中，裂解原料和水分别进入预热段的不同管层中。例如，在预热段包括或是两层的管时，可以将水送入内管(第1管层)，将裂解原料送入外层管(第2管层)。例如，在预热段包括三层的管时，可以将裂解原料送入第1和第3管层，将水送入第2管层(即中间管层)。优选地，水不被送入最外侧的管层。
在一些实施方案中，将螺旋凸起设置在各管层的外侧管壁的内侧(内表面)上。
在本申请中，可以在外部对预热段进行加热。在具有相反螺旋方向的螺旋凸起的双层管的情况下，将水送入内管(第1管层)，将裂解原料送入外层(第2管层)，从而热量传递的顺序是外层管壁、裂解原料、内层管壁和水。在预热段内，裂解原料和水分别在螺旋凸起的作用下产生相反的旋流，减薄了管壁附近的滞留层，大大强化了管内传质和传热。在离开预热段进入轻质化段时，带着相反旋流的裂解原料和水充分接触，大大加快了轻质化反应的速度。而且，由于进入轻质化段前部的水在反应管内中心位置，距离外管壁较远，且温度是逐渐升高到接近临界温度或超过临界温度，所以大大减少了水对反应管外壁的腐蚀。
在本申请中，可以合适地设定所述双层管或更多层的管的各管层的厚度。例如，可以根据经过预热段的裂解原料和水的量和流速合适地设定各管层的厚度。在一些实施方式中，所述双层管的内层管内直径与外层管内直径之比为0.1-0.9，优选为0.4-0.6。例如，所述双层管的内层管内直径与外层管内直径之比可以为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8或0.9。
在一些实施方式中，所述螺旋凸起的螺旋高径比(螺旋单圈高与螺旋直径的比)为0.1-20，优选为1-10。例如，所述高径比可以为0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9、1、2、3、4、5、6、7、8、9、10、11、12、13、14、15、16、17、18或19。在一些实施方式中，所述螺旋凸起的凸径比(对于最内的管，为螺旋凸起高度与管内直径的比；对于其他管层，为螺旋凸起高度与该管层外层管内直径与内层管外直径的差值的比)为0.01-0.5，优选为0.02-0.1。例如，所述凸径比可以为0.02、 0.03、0.04、0.05、0.06、0.07、0.08、0.09、0.1、0.11、0.12、0.13、0.14、0.15、0.16、0.17、0.18、0.19、0.2、0.3或0.4。
所述螺旋凸起的横截面可以采用任何通常已知的形状，例如矩形、正方形、三角形、梯形、半圆形、半椭圆形等等。螺旋凸起高度限定为从管壁到螺旋凸起的横截面的最高点的高度。
本领域技术人员可以合适地选择所述预热段、轻质化段、减压气化段和裂解段的体积。在一些实施方式中，所述预热段、轻质化段、减压气化段和裂解段的体积比为0.1-10∶0.1-1000∶0.1-10∶1，优选为0.1-7∶1-300∶0.1-7∶1，优选为0.1-5∶1-300∶0.1-7∶1，优选为0.1-0.5∶1-300∶0.1-0.5∶1。例如，当所述裂解反应装置包括反应管并且每根反应管包括依次相连的所述预热段、轻质化段、减压气化段和裂解段时，可以通过设置各段的管长度和/或直径来调节体积。
优选地，本发明提供一种裂解反应装置，该裂解反应装置包括：裂解原料进料口、裂解产物出口、依次相连的加压段、预热段、轻质化段、减压气化段、裂解段和急冷段，所述裂解原料进料口设置在所述预热段，所述裂解产物出口设置在所述急冷段，其中，所述预热段、所述轻质化段、所述减压气化段、所述裂解段、所述急冷段分别配置有控温装置以在使用时控制各段的温度，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低；所述预热段结构为双层管，且所述双层管的内层管内壁和/或外层管内壁设有螺旋凸起。
图2示出了可以用于本申请中的一种预热段，其为双层管。所述双层管包括内层管10和外层管11。内层管10内直径与外层管11内直径的比可以为0.1-0.9，优选为0.4-0.6。所述内层管内壁和所述外层管内壁上分别设置有螺旋凸起。所述内层管内壁上的螺旋凸起与所述外层管内壁上的螺旋凸起的螺旋方向相反。所述内层管内壁上的螺旋凸起的螺旋高径比(螺旋单圈高与螺旋直径的比)为0.1-20，优选为1-10。所述外层管内壁上的螺旋凸起的螺旋高径比(螺旋单圈高与螺旋直径的比)为0.1-20，优选为1-10。所述内层管内壁的螺旋凸起的凸径比(凸起高度与管内直径的比)为0.01-0.5，优选为0.02-0.1。所述外层管内壁的螺旋凸起的凸径比(凸起高度与外层管内直径和内层管外直径的差值的比)的0.01-0.5，优选为0.02-0.1。
图3示出了可以用于本申请中的一种预热段，其为三层管。所述三层管的每一层管壁的内侧上具有螺旋凸起。
在本发明的一些实施方式中，在所述预热段包括或为双层管或更多层的管的情况下，裂解原料和水可以分别进入预热段的不同管层中。例如，对于双层管的情况，裂解原料和水可以分别进入预热段内层管和内外层管之间。在外加热情况下，在预热段，内层管走水，内外层管之间走裂解原料，热量传递的顺序是外层管、裂解原料、内层管、水。由于进入轻质化段前部的水在反应管内中心位置，距离外管壁较远，且温度是逐渐升高到接近或超过临界温度的，大大减少了对反应管外管壁的腐蚀。此外，如果存在螺旋凸起，则裂解原料和水分别在螺旋凸起的作用下产生相反的旋流，减薄了管壁附近的滞留层，大大强化了管内传质和传热。在离开预热段进入轻质化段时，带着相反旋流的裂解原料和水充分接触，大大加快了轻质化反应的速度。
在本发明的一些实施方式中，所述预热段、所述轻质化段、所述减压气化段、所述急冷段和所述裂解段的体积比为0.1-10∶0.1-1000∶0.1-10∶0.1-10∶1，优选为0.1-0.5∶1-300∶0.1-0.5∶0.1-0.5∶1。
在本发明的一些实施方式中，对所述减压器件的具体形式不做限定，只要能够实现减压的目的即可。优选地所述减压器件可以为减压阀、压力控制阀或节流元件。
在本发明的一些实施方式中，所述加压段设置有加压设备。优选地，所述加压设备为泵。
在本发明的一些实施方式中，所述裂解反应装置包括一根或多根反应管。具体地，所述每根反应管均设置有依次相连的加压段、预热段、轻质化段、减压气化段、裂解段和任选地急冷段。所述反应管的排列方式可以为水平式、垂直式或悬挂式。
本发明中，所述裂解反应装置的加热方式不做限定。例如，可以通过电加热或底部烧嘴燃烧可燃气体进行加热。本发明对可燃气体的种类不做特别限定，可以使用本领域中已知的各种可用的可燃气体。所述预热段、所述轻质化段、所述减压气化段、所述裂解段可以分别配置有控温装置以在使用时控制各段的温度依次提高，温度增幅优选在150-250℃范围内。例如，所述预热段、所述轻质化段、所述减压气化段、所述裂解段、所述急冷段分别配置有控温装置以在使用时控制 各段的温度依次为150-250℃、350-450℃、550-650℃、770-880℃、450-550℃。
本发明中，可以将某一段得到的产物进行分离，以其部分产物进入下一段继续后续流程，这也属于本发明保护范围。
在一些实施方式中，在所述裂解反应装置包括反应管并且每根反应管包括依次相连的所述预热段、轻质化段、减压气化段和裂解段的情况中，在以上任何两段之间不存在对产物进行分离的操作；即上游段的产物被全部送入该段下游的段中。
根据本发明一个具体的实施方式，参考图1，示出了裂解反应装置。该裂解反应装置包括：进料口3、裂解产物出口9、依次相连的加压段(本实施方式通过加压设备实现加压，即图1中的水泵1和原油泵2)、预热段4、轻质化段5、减压气化段6、裂解段7和急冷段8，所述进料口3设置在所述预热段4，所述裂解产物出口9设置在所述急冷段8。可选地，所述预热段4、所述轻质化段5、所述减压气化段6、所述裂解段7、所述急冷段8分别配置有控温装置以在使用时控制各段的温度。所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的轻质化的混合物的压力降低。如图所示，所述预热段4、所述轻质化段5、所述减压气化段6、所述裂解段7和急冷段8组成管反应器。
本发明另一方面提供一种裂解制备烯烃的方法，其特征在于，该方法包括以下步骤：
(1)对裂解原料和水进行加压；
(2)将加压后的裂解原料和水进行第一加热(预热)；
(3)将第一加热后的裂解原料和水进行第二加热并在水的存在下轻质化裂解原料得到轻质化的混合物；
(4)将轻质化的混合物进行减压气化并进行第三加热，获得第三加热后的混合物(减压气化)；和
(5)在蒸汽的存在下，在裂解温度裂解第三加热后的混合物以得到包含烯烃的裂解产物。
本发明另一方面提供一种裂解制备烯烃的方法，该方法包括：
(1)将裂解原料和水进行加压；
(2)将加压后的裂解原料和水进行第一加热(预热)；
(3)将第一加热后的裂解原料和水进行第二加热并在水的存在下轻质化裂解原料得到轻质化的混合物；
(4)将轻质化的混合物进行减压气化并进行第三加热(减压气化)，获得含蒸汽和裂解原料的轻质化反应产物的第三加热后的混合物；
(5)在蒸汽的存在下，裂解所述第三加热后的混合物以得到包含烯烃的裂解产物；和
(6)将所述裂解产物冷却。
在一些实施方式中，所述第一加热、第二加热、第三加热和裂解的温度依次提高。优选地，从步骤(2)到步骤(5)，相邻步骤之间温度增幅在150-250℃范围内。
在本发明的一些实施方式中，所述第一加热、第二加热、第三加热和裂解的温度依次提高且增幅在150-250℃、优选在150-250℃范围内。在一些实施方式中，优选地，所述第一加热、第二加热、第三加热和裂解的温度分别为150-250℃、350-450℃、550-650℃和770-880℃。
在本发明的一些实施方式中，步骤(1)中，所述水和裂解原料的重量比为0.3-10.5，优选为0.5-5。例如，所述水和裂解原料的重量比可以为0.3、0.4、0.5、0.6、0.7、0.8、0.9、1、1.1、1.2、1.3、1.4、1.5、1.6、1.7、1.8、1.9、2、2.1、2.2、2.3、2.4、2.5、2.6、2.7、2.8、2.9、3、3.5、4或4.5。
本发明中，裂解的正反应是摩尔数增加的。降低压力和加入水(在反应条件下为水蒸气)均可以降低烃分压，有利于推动正反应，增加转化率。
在本申请中，所述裂解原料可以包含原油、渣油和原油经加工得到的重质烃中的至少一种。所述渣油可以包括常压渣油和减压渣油。在本发明的一些实施方式中，所述裂解原料为原油。
在本发明中，可以使用通常可以用于石油化工工艺中的任何水。例如，可以使用去离子水、循环水或再生水等等。
在加压步骤(第(1)步骤)中，将裂解原料和水加压到所需的压力。根据一些实施方式，将裂解原料和水加压到10-40MPa，优选15-30MPa，更优选21-30MPa。根据一些实施方式，所述压力可以为15MPa、16MPa、17MPa、18MPa、19MPa、20MPa、21MPa、22MPa、23MPa、24MPa、 25MPa、26MPa、27MPa、28MPa、29MPa、30MPa、31MPa、32MPa、33MPa、34MPa、35MPa、36MPa、37MPa、38MPa或39MPa。
所述加压步骤可以在输送裂解原料和水的管道中进行。例如，所述加压可以在将裂解原料和水送至预热步骤的管道中进行。所述加压可以通过本领域中已知的加压设备进行。优选地，所述加压设备为泵。
在对裂解原料和水进行加压后，对它们进行预热，即预热步骤(第(2)步骤)。
所述预热步骤用于对物料，包括所述裂解原料和水，进行预热。在预热步骤中，将待预热的物料，例如裂解原料和水，加热到期望的温度，例如不超过350℃的温度。在一些实施方式中，所述预热步骤将物料加热至例如150-250℃的温度。例如，所述预热段将物料加热至150℃、160℃、170℃、180℃、190℃、200℃、210℃、220℃、230℃、240℃、250℃、260℃、270℃、280℃、290℃、300℃、310℃、320℃、330℃或340℃。
在一些实施方式中，所述预热步骤包括使用加热容器和/或换热器。在使用加热容器的情况下，在把加压的裂解原料和水送入加热容器后，在加热容器中将裂解原料和水加热到期望的温度。在使用换热器的情况下，通过热交换将裂解原料和水加热到期望的温度。在一些实施方式中，所述预热步骤可以是管式反应器的一段(即管式反应器的预热段)。
在预热步骤中，物料(裂解原料和水)的压力为10-40MPa，优选15-30MPa，更优选21-30MPa。在一些实施方式中，预热步骤中的压力可以与加压步骤中的压力相同。
在本发明中，裂解原料可以单独进行加压和预热，并且水可以单独进行加压和预热，然后将加压和预热的裂解原料和加压和预热的水混合在一起。或者，裂解原料可以单独进行加压并且水可以单独进行加压；然后将加压的裂解原料和加压的水混合在一起得到混合物；并将得到的混合物加热到期望的预热温度。或者，可以将裂解原料和水混合，然后将混合物加压并预热。例如，可以将裂解原料和水加入容器中得到混合物，然后对容器中的混合物进行加压并预热。在一些实施方案中，第(1)和(2)步骤可以合并为一个步骤。
在本发明的一些实施方式中，加压后，裂解原料和水的压力为：10-40MPa，优选为15-30MPa，更优选为21-30MPa。本发明中，可 以将裂解原料和水分别加压到10-40MPa，优选为15-30MPa，更优选为21-30MPa。本发明中，可选地，将裂解原料和水混合并加压到10-40MPa，优选为15-30MPa，更优选为21-30MPa。
本发明中，加压是为了在轻质化反应中保持水和原油处于液态；也为了达到水的近临界或超临界状态；在此状态下传质、传热和反应都得以强化，轻质化反应速度快，不易结焦。
在本发明中，为避免裂解原料过早达到高温，导致在高温下停留时间过长造成结焦，同时为避免水过早到达超临界状态，对装置造成腐蚀，在轻质化处理之前设置了预热步骤。在预热步骤(步骤(2))中，所述第一加热的条件包括：将温度加热到不超过350℃，优选为150-250℃；压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。
在本申请的方法中，在预热步骤之后是轻质化处理步骤。在本申请中，“轻质化”是指在超临界水或接近超临界水的温度和压力下对物料进行处理。
在本发明的一些实施方式中，步骤(3)(轻质化处理步骤)中，所述轻质化处理的条件可以包括：温度为350-450℃，压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。可以合理地选择轻质化处理的时间，以得到所需的轻质化处理产物。例如，轻质化步骤的处理时间可以为0.2分钟至240分钟，优选0.5分钟至60分钟，更优选为1-10分钟。
在一些实施方案中，在轻质化段中，裂解原料和水被进一步加热，例如加热到300-540℃、优选300-500℃、更优选350-450℃的温度。例如，在轻质化段中，裂解原料和水被加热到310℃、320℃、330℃、340℃、350℃、360℃、370℃、380℃、390℃、400℃、410℃、420℃、430℃、440℃、450℃、460℃、470℃、480℃、490℃、500℃、510℃、520℃或530℃。
在轻质化处理步骤中，在超临界水或接近超临界水的温度和压力下，裂解原料(例如原油)和水发生反应(轻质化)，使得裂解原料中的至少部分重组分大分子转化较小分子，从而更适宜作为蒸汽热裂解的原料。轻质化所需的水在裂解阶段还能起到稀释蒸汽的作用。轻质化反应后的混合物(轻质化的混合物)中含有蒸汽和裂解原料的轻质化反应产物。
在轻质化处理步骤中，来自预热步骤的裂解原料和水被进一步加热，例如加热到350-450℃的温度。在轻质化处理步骤中，裂解原料和水的压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。在一些实施方式中，轻质化处理步骤的压力可以与预热步骤中的压力和/或加压步骤中的压力相同。
在本申请的轻质化处理步骤中，水处于近临界或超临界状态。在本申请的轻质化处理步骤中，裂解原料(例如原油)在近临界或超临界水的存在下发生反应，使得裂解原料中的至少部分重组分大分子转化为较小分子，得到轻质化的混合物。
在一些实施方式中，所述轻质化处理步骤在轻质化容器例如轻质化反应釜中进行。或者，所述轻质化处理步骤在管式反应器中进行(即管反应器的轻质化段)。
在一些实施方式中，轻质化反应釜可以为多台串联或并联，在部分轻质化反应釜排出反应物至减压气化段时，部分轻质化反应釜引入裂解原料和水，以及部分轻质化反应釜在进行轻质化反应，以保持本申请方法的连续稳定运行。
在一些实施方式中，加压和预热后的裂解原料和水在轻质化处理步骤中，在350-450℃和21-30MPa的条件下，反应1-120min，得到轻质化的混合物。
本申请的方法还包括在轻质化处理之后的减压气化步骤(步骤(4))，以得到气态混合物。在本发明的一些实施方式中，为提高烯烃收率，步骤(4)中，所述减压使得所述轻质化反应后的混合物的压力降为0.01-0.5MPa，优选为0.1-0.4MPa。例如，所述混合物的压力可以降低至0.02MPa、0.03MPa、0.04MPa、0.05MPa、0.06MPa、0.07MPa、0.08MPa、0.09MPa、0.1MPa、0.15MPa、0.2MPa、0.25MPa、0.3MPa、0.35MPa、0.4MPa或0.45MPa。
值得注意的是，在本申请的方法中，在减压气化步骤(步骤(4))中，轻质化反应后的混合物(轻质化的混合物)虽然压力降低，但是温度却没有降低。优选地，在使所述轻质化反应后的混合物的压力降低的同时或之后，进行所述第三加热使得所述轻质化反应后的混合物的温度进一步升高，优选地升至550-650℃。减压气化段中的所述加热使得所述混合物的温度升至例如550-700℃，优选550-650℃。例如，减压气化 段中的所述加热使得所述混合物的温度可以升至560℃、570℃、580℃、590℃、600℃、610℃、620℃、630℃、640℃、650℃、660℃、670℃、680℃或690℃。
在一些实施方式中，所述减压气化步骤在减压气化容器中进行。可选地，所述减压气化步骤在管式反应器中进行(即管反应器的减压气化段)。
在本申请的方法中，在减压气化后，将减压气化得到的混合物(气态混合物)进行蒸汽裂解(步骤(5)，裂解步骤)。
在本发明的方法中，裂解反应是强吸热、摩尔数增大、有大量副反应的反应体系。所以，高温、低压、短停留时间是有利于裂解反应生产烯烃的工艺条件。
蒸汽裂解是本领域中已知的操作。本领域技术人员可以根据待裂解的原料和希望得到的裂解产物合理地选择裂解操作所需要的条件。例如，具体地，在蒸汽裂解步骤(步骤(5))中，所述裂解反应的条件包括：温度为770-880℃，优选为780-820℃，压力为0.01-0.5MPa，优选为0.2-0.3MPa，停留时间0.1-0.5秒。在裂解段中，物料被加热到裂解温度；优选地，物料被加热到710-900℃、优选770-880℃、更优选为780-820℃的温度。在裂解段中，压力为0.01-0.5MPa，优选为0.1-0.4MPa。例如，在裂解段中，物料被加热到720℃、730℃、740℃、750℃、760℃、770℃、780℃、790℃、800℃、810℃、820℃、830℃、840℃、850℃、860℃、870℃、880℃或890℃。例如，在裂解段中，压力可以为0.02MPa、0.03MPa、0.04MPa、0.05MPa、0.06MPa、0.07MPa、0.08MPa、0.09MPa、0.1MPa、0.15MPa、0.2MPa、0.25MPa、0.3MPa、0.35MPa、0.4MPa或0.45MPa。例如，物料在裂解段中的停留时间可以为0.1秒、0.2秒、0.3秒、0.4秒或0.5秒。
在一些实施方式中，所述裂解步骤在裂解器中进行。所述裂解器可以是本领域中通常已知的裂解器，例如蒸汽裂解器。在一些实施方式中，所述裂解步骤在管式反应器中进行(即管反应器的裂解段)。
任选地，本申请的方法还可以包括在所述裂解步骤之后的冷却(急冷)步骤。在裂解后对裂解产物进行冷却(急冷)是本领域中已知的。
本领域技术人员可以根据裂解产物合理地选择冷却所需要的条件。在本发明的一些实施方式中，在冷却步骤(步骤(6))中，在0.1秒内，所 述冷却使得裂解产物的温度不高于550℃(例如冷却至450-550℃)，压力为0.01-0.5MPa，优选为0.2-0.3MPa。
在一些实施方式中，所述急冷步骤可以在本领域中通常已知的急冷设备中实施。
本发明中，本申请的所述方法可以在上述的本申请的裂解反应装置中实施。其中，所述加压段用于将裂解原料和水进行加压。所述预热段用于将加压后的裂解原料和水进行第一加热。所述轻质化段用于将第一加热后的裂解原料和水进行第二加热，并使得裂解原料在超临界水或近临界水的存在下发生轻质化反应。所述减压气化段用于将轻质化反应后的混合物进行减压并进行第三加热，获得第三加热后的含蒸汽和裂解原料的轻质化反应产物的混合物。所述裂解段用于在蒸汽的存在下，使所述混合物发生裂解反应。所述急冷段用于将裂解反应后的裂解产物迅速冷却，防止反应原料在高温下停留时间过长导致结焦。
根据一个优选的实施方式，本申请的方法的第(2)至第(5)步骤(即预热步骤、轻质化处理步骤、减压气化步骤和裂解步骤)在以上所述的包括反应管的裂解反应装置中进行，其中所述反应管包括依次相连的预热段、轻质化段、减压气化段和裂解段来分别实施预热步骤、轻质化步骤、减压气化步骤和裂解步骤。更优选地，当使用包括反应管的裂解反应装置时，在预热步骤、轻质化处理步骤、减压气化步骤和裂解步骤的步骤之间，不存在对产物进行分离的操作；即上游步骤的产物被全部送入下游步骤中。
如本领域技术人员所理解的那样，本申请上文中描述的裂解反应装置可以用在本申请的方法中。因此，本申请装置部分中描述的特征如适用也可应用于本申请的方法；反之亦然。
在本申请中，针对各段或各步骤给出的温度或压力范围，是希望在本段或步骤中实现的温度或压力。但是，如本领域技术人员知晓的那样，温度或压力值的实现需要一个过程。例如，如果预热步骤将物料加热至200℃的温度，则在开始加热时，物料的温度会低于200℃，并随着加热的进行而升高到200℃。例如，在预热步骤在管式反应器中进行时(管预热段)，物料在管预热段的入口处低于200℃，随着物料在管内的流动，其温度升高并达到200℃。例如，对于双层管，内外管层 物料在预热段逐渐加热，在预热段出口处的平均温度达到200℃。
本发明第三方面提供本申请的上述裂解反应装置在裂解制备烯烃中的应用。例如，本申请的裂解反应装置可用于重质原料例如原油的裂解，优选蒸汽裂解。
本发明中，所述压力均为绝压。
本发明中，裂解制备得到的低碳烯烃包括乙烯、丙烯和丁二烯。
实施例
以下将通过实施例对本发明进行详细描述。
以下实施例和对比例中所用的原油的组成如表1所示。该组成根据模拟蒸馏分析方法ASTM D5307测得。使用安捷伦7890气相色谱仪实施测量。
表1
分析项目 ASTM D5307
IP，℃ 69
10％，℃ 192
20％，℃ 272
30％，℃ 337
40％，℃ 393
50％，℃ 446
60％，℃ 508
70％，℃ 595
75％，℃ 653
80％，℃ -
90％，℃ -
EP，℃ -
注：“-”表示无法测出。
轻质化实施例
原油和水分别在管式轻质化反应装置和带搅拌的反应釜中，在超临界或接近超临界的水中进行轻质化处理。结果见表A和表B。反应 装置和条件如下：轻质化原油a(表2中实施例1的预热段和轻质化段组成的管式轻质化反应装置；水油比1.5；预热段温度250℃压力27MPa；轻质化段温度440℃压力27MPa，停留时间15min)；轻质化原油b(反应装置同轻质化原油a；水油比1.5；预热段温度250℃压力24MPa；轻质化段温度430℃，压力24MPa，停留时间15min)；轻质化原油c(在容积110mL带搅拌釜式轻质化反应器中，水量28g，水油比1.5，430℃，32MPa，搅拌速度600r/min，反应15min)；轻质化原油d(表2中实施例1的预热段和轻质化段组成的管式轻质化反应装置但无螺旋结构，水油比1.5，预热段温度250℃压力30MPa；轻质化段430℃，30MPa，停留时间15min)。
表A
Figure PCTCN2022127962-appb-000001
表B
Figure PCTCN2022127962-appb-000002
Figure PCTCN2022127962-appb-000003
注：轻组分为沸点低于220℃组分总和，重组分为沸点高于500℃组分总和。
由表A结果，原油中沸点轻组分从约12％分别提高到了32％、24％、20％和12％；原油中重组分从约40％降低到4％、8％、19％和25％。相应的，原油中沸点轻组分增幅为166.7％、100％、66.7％和0％，原油中重组分降幅为90％、80％、52.5％和37.5％
从轻质化处理前后原油的模拟蒸馏数据可以看出，原油经过轻质化反应后，部分重组分转化为轻组分。
实施例1-6
在本申请的裂解反应装置中由原油和水制备低碳烯烃。该裂解反应装置包括：水泵，原油泵，进料口、预热段、轻质化段、减压气化段、裂解段和急冷段、裂解产物出口，依次连接。所述预热段、轻质化段、减压气化段、裂解段和急冷段设置为管反应器。所述预热段结构为双层管，所述双层管的内壁设有方向相反的螺旋凸起(截面形状为矩形，宽度为1mm)。裂解原料和水进入裂解反应装置依次进行加压、第一加热(预热)、第二加热(轻质化)、第三加热(减压气化)、裂解和冷却。所述水泵、原油泵用于将裂解原料和水进行加压；所述预热段用于将加压后的裂解原料和水进行第一加热；裂解原料和水通过进料口进入预热段，水走预热段内层管，裂解原料走预热段内外层管之间；所述轻 质化段用于将第一加热后的裂解原料和水进行第二加热，并使得裂解原料在水的存在下发生轻质化反应；所述减压气化段用于将轻质化反应后的混合物先进行减压再进行第三加热，获得第三加热后的含蒸汽和裂解原料的轻质化反应产物的混合物；所述裂解段用于在蒸汽的存在下，使所述第三加热后的混合物发生裂解反应；所述急冷段用于将裂解反应后的裂解产品冷却，裂解反应产物由急冷段上的裂解产物出口引出。
裂解反应装置规格见表2；各段的工艺参数见表3。以原油和水为原料，在特定的原料和水的重量比、各段温度、各段压力条件下进行裂解，所得裂解产物(烯烃)结果见表4。
实施例1-6中，裂解段为内径10mm、长1米的管。
实施例1-6中，除实施例6中轻质化段管内径为32mm之外，其他各段管内径均为10mm。
表2 各管式裂解装置结构参数
Figure PCTCN2022127962-appb-000004
Figure PCTCN2022127962-appb-000005
表3
Figure PCTCN2022127962-appb-000006
注：急冷段温度是指在0.1秒内，裂解产物冷却后的温度。
对比例1
利用乙烯工业装置中的已知的SRT-IV型裂解反应装置，以组成如表1的原油为原料，在水和原油的重量比为0.75，裂解反应装置辐射 段出口温度780℃，压力0.27MPa，停留时间0.2秒条件下进行裂解反应，收集裂解产品，其烯烃含量见表4。
裂解反应装置运行周期定义为：裂解反应装置从开始运行，到因为结焦而不得不烧焦停止运行的时间。
乙烯收率(wt％)＝裂解所得乙烯重量/原油进料重量×100％
丙烯收率(wt％)＝裂解所得丙烯重量/原油进料重量×100％
丁二烯收率(wt％)＝裂解所得丁二烯重量/原油进料重量×100％
三烯总收率(wt％)＝乙烯收率+丙烯收率+丁二烯收率
具体结果见表4。
表4
Figure PCTCN2022127962-appb-000007
通过表4的结果可以看出，实施例1-6，采用本发明的技术方案，所得的乙烯、丙烯和丁二烯的收率较高，三烯总收率也较高，并且设备运行时间长。对比例1未采用本发明的技术方案，所得的乙烯、丙烯和丁二烯的收率较低，三烯总收率也较低，并且设备运行周期仅仅维持12小时，反应管就因为结焦过于严重而不得不烧焦。
以上详细描述了本发明的优选实施方式，但是，本发明并不限于此。在本发明的技术构思范围内，可以对本发明的技术方案进行多种简单变型，包括各个技术特征以任何其它的合适方式进行组合，这些简单变型和组合同样应当视为本发明所公开的内容，均属于本发明的保护范围。

Claims (21)

  1. 一种裂解反应装置，其特征在于，所述裂解反应装置包括依次相连的预热段、轻质化段、减压气化段和裂解段。
  2. 根据权利要求1所述的裂解反应装置，其中，所述轻质化段包括轻质化容器，优选轻质化釜。
  3. 根据权利要求1或2所述的裂解反应装置，其中，所述预热段包括加热容器或换热器，和/或
    所述减压气化段包括减压气化容器，和/或
    所述裂解段包括裂解器。
  4. 根据权利要求1所述的裂解反应装置，其中，所述裂解反应装置包括一根或多根反应管并且每根反应管包括依次相连的所述预热段、轻质化段、减压气化段和裂解段；任选地，各段的管径可以彼此相同或不同。
  5. 根据权利要求1-4中任一项所述的裂解反应装置，其中，所述裂解反应装置还包括在预热段之前的加压段，和/或在所述裂解段之后的急冷段。
  6. 根据权利要求1-5中任一项所述的裂解反应装置，其中，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低；优选地，所述减压器件为减压阀、压力控制阀或节流元件。
  7. 根据权利要求1-6中任一项所述的裂解反应装置，其中，所述预热段、轻质化段、减压气化段和裂解段的温度是顺序提高的；优选地，所述预热段、轻质化段、减压气化段和裂解段的温度依次为150-250℃、350-450℃、550-650℃和770-880℃。
  8. 根据权利要求1-7中任一项所述的裂解反应装置，其中，所述预热段为双层管或更多层管。
  9. 根据权利要求8所述的裂解反应装置，其中，所述双层管或更多层管的内层管内壁和/或外壁上和/或中间层的管壁上和/或外层管内壁上设有螺旋凸起。
  10. 根据权利要求8或9所述的裂解反应装置，其中，所述双层管的内层管内直径与外层管内直径之比为0.1-0.9，优选为0.4-0.6；
    和/或，相邻管层内的螺旋凸起的螺旋方向相反；
    和/或，所述螺旋凸起的螺旋高径比为0.1-20，优选为1-10；
    和/或，所述螺旋凸起的凸径比为0.01-0.5，优选为0.02-0.1。
  11. 根据权利要求5所述的裂解反应装置，其中，所述加压段设置有加压设备；优选地，所述加压设备为泵。
  12. 根据权利要求1-11任一项所述的裂解反应装置，其中，所述预热段、轻质化段、减压气化段和裂解段的体积比为0.1-10∶0.1-1000∶0.1-10∶1，优选为0.1-0.5∶1-300∶0.1-0.5∶1。
  13. 一种裂解反应装置，其特征在于，该裂解反应装置包括：裂解原料进料口、裂解产物出口、依次相连的加压段、预热段、轻质化段、减压气化段、裂解段和急冷段，所述裂解原料进料口设置在所述预热段，所述裂解产物出口设置在所述急冷段，其中，所述预热段、所述轻质化段、所述减压气化段、所述裂解段、所述急冷段分别配置有控温装置以在使用时控制各段的温度，所述轻质化段与所述减压气化段之间配置有减压器件使得进入所述减压气化段的物料的压力降低；所述预热段结构为双层管，且所述双层管的内层管内壁和/或外层管内壁设有螺旋凸起。
  14. 一种裂解制备烯烃的方法，其特征在于，该方法包括以下步骤：
    (1)将裂解原料和水进行加压；
    (2)将加压后的裂解原料和水进行第一加热；
    (3)将第一加热后的裂解原料和水进行第二加热并在水的存在下轻质化裂解原料得到轻质化的混合物；
    (4)将轻质化的混合物进行减压气化并进行第三加热，获得第三加热后的混合物；和
    (5)在蒸汽的存在下，在裂解温度下裂解第三加热后的混合物以得到包含烯烃的裂解产物。
  15. 根据权利要求14所述的方法，其中，所述第一加热、第二加热、第三加热和裂解的温度依次提高；优选地，从步骤(2)到步骤(5)，相邻步骤之间温度增幅在100-250℃、优选150-250℃范围内；更优选地，所述第一加热、第二加热、第三加热和裂解的温度依次为150-250℃、350-450℃、550-650℃和770-880℃；
    和/或，步骤(1)中，所述水和裂解原料的重量比为0.3-10.5，优选 为0.5-5；
    和/或，所述裂解原料为原油、渣油和原油经加工得到的重质烃中的至少一种。
  16. 根据权利要求14或15所述的方法，其中，步骤(1)中，加压后，裂解原料和水的压力为：10-40MPa，优选为15-30MPa，更优选为21-30MPa；
    和/或，步骤(2)中，所述第一加热的条件包括：温度低于350℃，优选为150-250℃；压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa。
  17. 根据权利要求14-16中任意一项所述的方法，其中，步骤(3)中，所述轻质化在超临界水或者接近超临界水的条件下进行；优选地，所述轻质化的条件包括：温度为300-500℃，优选350-450℃；压力为10-40MPa，优选为15-30MPa，更优选为21-30MPa；
    和/或，步骤(4)中，所述减压使得所述轻质化的混合物的压力降低至0.01-0.5MPa，优选为0.1-0.4MPa；和所述第三加热使得所述轻质化的混合物的温度升至550-700℃，优选550-650℃。
  18. 根据权利要求14-17中任意一项所述的方法，其中，步骤(5)中，所述裂解的条件包括：温度为710-900℃，优选770-880℃，更优选为780-820℃，压力为0.01-0.5MPa，优选为0.1-0.4MPa，和停留时间为0.1-0.5秒。
  19. 根据权利要求14-18中任意一项所述的方法，其中，该方法还包括：
    (6)冷却裂解反应后得到的裂解产物；优选地，步骤(6)中，在0.1秒内，所述冷却使得裂解产品的温度不高于550℃，和压力为0.01-0.5MPa，优选为0.1-0.4MPa。
  20. 根据权利要求14-19中任意一项所述的方法，其中，所述方法在权利要求1-13中任意一项所述的裂解反应装置中进行。
  21. 权利要求1-13中任意一项所述的裂解反应装置在裂解制备烯烃中的应用。
PCT/CN2022/127962 2021-10-28 2022-10-27 裂解反应装置、裂解制备烯烃的方法及应用 WO2023072196A1 (zh)

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