Crude oil steam cracking method, evaluation system and evaluation method

Abstract

The invention relates to the technical field of petrochemical engineering, and provides a crude oil steam cracking method, an evaluation system and an evaluation method.The evaluation system comprises a crude oil treatment device and a cracking and product separation device which are connected; the crude oil treatment device comprises a first flash evaporation unit, a second flash evaporation unit and a buffer unit, the first flash evaporation unit is connected with a raw material supply unit and a steam supply unit, the second flash evaporation unit is connected with the first flash evaporation unit, and the buffer unit is connected with the first flash evaporation unit; the cracking and product separating device comprises a cracking heating furnace, a liquid supply unit and a cooling unit, a convection section and a radiation section which are parallel are arranged in the cracking heating furnace, the convection section is respectively connected with the second flash evaporation unit and the buffer unit, the liquid supply unit is connected with the convection section, and an outlet of the radiation section of the cooling unit is connected. The problem that the crude oil steam cracking process lacks flexible crude oil fraction separation and cracking process condition guidance can be solved, the crude oil steam cracking performance evaluation is completed, and an efficient steam cracking utilization scheme is obtained.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a crude oil steam cracking method, evaluation system, and evaluation method. Background Technology

[0002] The ethylene industry is the leading sector in the development of the petrochemical industry, and its level is a crucial indicator of the overall development of the petrochemical industry. Hydrocarbon steam cracking is the most important technology for producing ethylene. Using hydrocarbons such as ethane, C3, C4, light hydrocarbons, naphtha, light diesel oil, and hydrotreated tail oil as feedstock, it boasts a high ethylene yield and co-produces basic chemical feedstocks such as propylene, butadiene, benzene, toluene, xylene, C5, and C9, playing a pivotal role in the petrochemical industry. With rapid economic development, the ever-increasing production of low-carbon olefin organic chemical feedstocks such as ethylene still cannot meet the growing product demand. Furthermore, with the continuous expansion of ethylene cracking unit capacity, the supply of ethylene cracking feedstocks is showing a trend of shortage. To address this issue, ethylene cracking feedstocks are gradually developing towards heavier and more diversified directions. Among them, crude oil steam cracking technology, using crude oil as cracking feedstock, can shorten or eliminate the refining process, offering advantages such as low carbon emissions, low feedstock costs, and low investment costs, making it an important direction for enterprises to achieve high-quality transformation and cost reduction and efficiency improvement.

[0003] The main reason why crude oil is unsuitable as a feedstock for steam cracking is its complex composition, wide distillation range, and lack of matching cracking processes. Furthermore, its high-boiling-point substances (>520℃) and gums easily cause carbon formation and coking during high-temperature steam cracking, leading to increased energy consumption and shortened operating cycles in the cracking furnace, severely impacting the operational stability and economic efficiency of ethylene plants. To achieve direct steam cracking utilization of crude oil, it is necessary to separate suitable fractions from the crude oil for ethylene cracking and employ appropriate cracking processes to maximize the product yield in the crude oil-to-olefins process. Due to the significant differences in the properties and composition of different crude oils, cracking plants lack reasonable and effective crude oil utilization schemes. However, applying a steam cracking simulation and evaluation system to assess the cracking performance of cracking feedstocks and their fractions allows for flexible and accurate understanding of the steam cracking performance of different feedstocks and their fractions, as well as suitable cracking process conditions. This provides operational guidance for ethylene production plants, helps improve energy and material consumption, and enhances the overall economic efficiency of the plant.

[0004] Crude oil is a mixture of various distillate fractions, including light hydrocarbons, light naphtha fractions, heavy naphtha fractions, kerosene fractions, diesel fractions, and wax oil fractions. Due to the significant differences in the composition of different crude oil fractions, the required cracking process conditions also differ. Furthermore, commonly used steam cracking simulation and evaluation systems lack dedicated processing units for crude oil preheating feed and fraction separation, which cannot meet the needs of crude oil steam cracking experimental evaluation. As a result, the existing crude oil steam cracking process lacks flexible guidance on crude oil fraction separation and cracking process conditions, leading to unsatisfactory results in crude oil steam cracking for olefin production. Summary of the Invention

[0005] The purpose of this invention is to provide a crude oil steam cracking method, evaluation system, and evaluation method that can solve the problem of the lack of flexible crude oil fraction separation and cracking process conditions guidance in the current crude oil steam cracking process. It can quickly complete the evaluation of crude oil steam cracking performance, obtain efficient crude oil steam cracking utilization schemes, and predict the yield and output of crude oil steam cracking to olefins.

[0006] The above-mentioned technical objectives of this invention are mainly achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a crude oil vapor cracking method, comprising:

[0008] After crude oil is mixed with steam, it enters the first flash tank for first flash separation to obtain the first gas phase fraction and the first liquid phase fraction.

[0009] The first gaseous fraction is passed into the second flash tank for second flash separation to obtain the second gaseous fraction and the second liquid fraction. At the same time, the first liquid fraction is passed into the buffer tank to obtain the third liquid fraction.

[0010] The second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction are respectively fed into the convection section of the pyrolysis heating furnace for heating, and then respectively enter the radiation section of the pyrolysis heating furnace for pyrolysis.

[0011] The pyrolysis gas generated in the pyrolysis heating furnace by the second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction is cooled.

[0012] In a preferred embodiment of the present invention, the convection section inside the pyrolysis heating furnace is connected to a water supply unit;

[0013] Within the convection section of the pyrolysis furnace, the second vapor fraction, the second liquid fraction, and the third liquid fraction are mixed with water and / or steam supplied by the water supply unit, respectively.

[0014] In a preferred embodiment of the present invention, a gas supply unit is connected between the convection section and the radiation section of the pyrolysis heating furnace;

[0015] After the crude oil is cracked, the air in the gas supply unit enters the radiant section of the cracking furnace for coking.

[0016] Secondly, the present invention also provides a crude oil steam cracking evaluation system, which includes a crude oil processing unit and a cracking and product separation unit connected together.

[0017] The crude oil processing unit includes:

[0018] The first flash unit has an inlet connected to a raw material supply unit and a steam supply unit.

[0019] The second flash unit has its inlet connected to the gas phase outlet of the first flash unit;

[0020] A buffer unit, the inlet of which is connected to the liquid phase outlet of the first flash evaporation unit;

[0021] The pyrolysis and product separation device includes:

[0022] The pyrolysis heating furnace is provided with three sets of parallel convection sections and radiation sections. Each set of convection sections and radiation sections are connected. The three sets of convection sections are respectively connected to the gas phase outlet of the second flash evaporation unit, the liquid phase outlet of the second flash evaporation unit, and the liquid phase outlet of the buffer unit.

[0023] The three sets of liquid supply units are respectively connected to the inlets of the three sets of convection sections;

[0024] The cooling unit is connected to the outlets of the three sets of radiation sections.

[0025] In a preferred embodiment of the present invention, the raw material supply unit includes:

[0026] A raw material tank for storing crude oil, wherein the raw material tank is equipped with a stirrer and a raw material tank heater;

[0027] The first measuring device, wherein the raw material tank is placed on the first measuring device via a raw material tank support;

[0028] A raw material supply pipe is connected between the raw material tank and the first flash evaporation unit, and a raw material pump and a raw material preheater are provided on the raw material supply pipe.

[0029] In a preferred embodiment of the present invention, the steam supply unit includes:

[0030] The first water tank is used to store water;

[0031] A second measuring device, on which the first water tank is placed;

[0032] A steam supply pipe is connected between the first water tank and the first flash evaporation unit, and a first water pump and a vaporizer are provided on the steam supply pipe.

[0033] In a preferred embodiment of the present invention, the first flash evaporation unit includes:

[0034] A first flash tank has an inlet, a gas phase outlet, and a liquid phase outlet. The inlet of the first flash tank is connected to the raw material supply unit and the steam supply unit.

[0035] The first flash heater is located on the pipe connected to the inlet of the first flash tank.

[0036] In a preferred embodiment of the present invention, the second flash evaporation unit includes:

[0037] The second flash tank has an inlet, a gas phase outlet and a liquid phase outlet. The inlet of the second flash tank is connected to the gas phase outlet of the first flash tank through a first gas phase distillation pipe. The gas phase outlet of the second flash tank is connected to a second gas phase distillation pipe, and the liquid phase outlet of the second flash tank is connected to a second liquid phase distillation pipe.

[0038] The second flash heater is located on the first vapor phase distillation tube.

[0039] In a preferred embodiment of the present invention, the buffer unit includes:

[0040] A buffer tank has a first inlet and a liquid phase outlet. The first inlet of the buffer tank is connected to the liquid phase outlet of the first flash tank through a first liquid phase distillation pipe, and the liquid phase outlet of the buffer tank is connected to a third liquid phase distillation pipe.

[0041] In a preferred embodiment of the present invention, the buffer tank further has a second inlet, which is connected to the liquid phase outlet of the second flash tank via a fourth liquid phase distillation pipe.

[0042] In a preferred embodiment of the present invention, a first liquid phase distillation pipe is connected to the first liquid phase distillation pipe; and / or

[0043] The second vapor fraction pipe is connected to a second vapor fraction discharge pipe; and / or

[0044] A second liquid phase fraction discharge pipe is connected to the second liquid phase fraction pipe or the fourth liquid phase fraction pipe; and / or

[0045] The third liquid phase distillation pipe is connected to a third liquid phase distillation discharge pipe.

[0046] In a preferred embodiment of the present invention, a first heating coil is provided inside the first flash tank, and a first heating wire is sleeved around the outer periphery of the first flash tank; and / or

[0047] The second flash evaporator is equipped with a second heating coil, and a second heating wire is fitted around the outer periphery of the second flash evaporator; and / or

[0048] The buffer tank is equipped with a third heating coil, and the buffer tank is fitted with a third heating wire on its outer periphery.

[0049] In a preferred embodiment of the present invention, the pyrolysis heating furnace includes:

[0050] The first convection section furnace tube and the first radiation section furnace tube are connected, and the first convection section furnace tube is connected to the second gas phase distillation tube;

[0051] The second convection section furnace tube and the second radiation section furnace tube are connected together, and the second convection section furnace tube is connected to the second liquid phase distillation tube;

[0052] The third convection section furnace tube and the third radiation section furnace tube are connected together, and the third convection section furnace tube is connected to the third liquid phase distillation tube.

[0053] In a preferred embodiment of the present invention, the three sets of liquid supply units include:

[0054] The second water tank is placed on the third metering device, and the second water tank is connected to the first convection section furnace tube through the first water supply pipe.

[0055] The third water tank is placed on the fourth metering device, and the third water tank is connected to the second convection section furnace tube through the second water supply pipe;

[0056] The fourth water tank is placed on the fifth metering device and is connected to the third convection section furnace tube via the third water supply pipe.

[0057] In a preferred embodiment of the present invention, the cooling unit includes:

[0058] The cooling tank has its inlet connected to the first radiant section furnace tube, the second radiant section furnace tube, and the third radiant section furnace tube via a first pyrolysis gas pipe.

[0059] The cryogenic tank has its inlet connected to the outlet of the cooling tank, and its outlet is connected to a second pyrolysis gas pipe.

[0060] In a preferred embodiment of the present invention, along the flow direction of the pyrolysis gas in the first pyrolysis gas pipe, a first quench cooler and a second quench cooler are sequentially provided on the first pyrolysis gas pipe; and / or

[0061] The pipes connected to the outlet of the cooling tank, the pipes connected to the inlet of the cryogenic tank, and the pipes connected to the outlet of the cryogenic tank are all fitted with a section of cooling pipe.

[0062] In a preferred embodiment of the present invention, the cooling tank is provided with a cooling coil; and / or, the cryogenic tank is provided with a cryogenic coil.

[0063] In a preferred embodiment of the present invention, the bottom of the cooling tank is connected to a cooling tank discharge pipe; and / or, the bottom of the cryogenic tank is connected to a cryogenic tank discharge pipe.

[0064] In a preferred embodiment of the present invention, along the flow direction of the pyrolysis gas in the second pyrolysis gas pipe, a pressure regulating valve, a gas buffer bottle and a flow meter are sequentially provided on the second pyrolysis gas pipe.

[0065] In a preferred embodiment of the present invention, the pyrolysis and product separation device includes a gas supply unit, the gas supply unit comprising:

[0066] The first gas supply pipe is connected to the pipe after the first convection section furnace tube and the second gas phase distillation pipe merge;

[0067] The second gas supply pipe is connected to the pipe where the second convection section furnace tube and the second liquid phase distillation pipe merge; the third gas supply pipe is connected to the pipe where the third convection section furnace tube and the third liquid phase distillation pipe merge.

[0068] Thirdly, the present invention also provides a crude oil vapor cracking evaluation method, which is implemented using the crude oil vapor cracking evaluation system described above, the crude oil vapor cracking evaluation method comprising:

[0069] Start the pyrolysis and product separation device. When the pyrolysis furnace heats up to the predetermined temperature and the cooling unit cools down to the predetermined temperature, turn on the liquid supply unit to supply water into the pyrolysis furnace.

[0070] Start the crude oil processing unit to raise the temperature of the first flash unit, the second flash unit and the buffer unit to the predetermined temperature;

[0071] The raw material supply unit and steam supply unit were started to supply materials to the first flash unit for preliminary experiments;

[0072] Conduct formal tests and record the supply and output of each raw material before and after the formal tests.

[0073] After the cracking and product separation unit and the crude oil processing unit have cooled down, shut them down.

[0074] In a preferred embodiment of the present invention, the pyrolysis and product separation device further includes a gas supply unit for introducing air into the pyrolysis heater; the crude oil steam pyrolysis evaluation method further includes:

[0075] After the cracking and product separation unit and the crude oil processing unit are shut down, the cracking and product separation unit is restarted. When the cracking furnace is heated to the predetermined temperature, the gas supply unit is turned on to introduce air into the cracking furnace for coking operation.

[0076] Compared with the prior art, the technical solution of the present invention has the following characteristics and advantages:

[0077] 1. This invention can quickly complete the evaluation of crude oil steam cracking performance and obtain a crude oil high-efficiency steam cracking utilization scheme: The crude oil steam cracking evaluation system has a crude oil processing device and a cracking and product separation device. The crude oil processing device can divide the crude oil into three fractions: light components, intermediate components, and heavy components, according to research needs. The cracking and product separation device can perform independent cracking analysis and evaluation on the above fractions.

[0078] 2. This invention can reduce the flash separation temperature: The crude oil processing unit adopts a micro-positive pressure flash evaporation method with oil-water mixed feed, which can protect crude oil components, inhibit raw material coking, and reduce the partial pressure of distillate materials.

[0079] 3. This invention can improve flash separation efficiency and prevent coking of heavy fractions due to excessively long distillation process: The flash process in the crude oil processing unit adopts a high-temperature followed by a low-temperature method, which simplifies the pipeline design of the separation process and facilitates water metering.

[0080] 4. This invention improves the convenience of research on crude oil steam cracking and the accuracy of crude oil steam cracking evaluation: The cracking and product separation device has three independent radiant section furnace tubes. Through independent cracking process control, individual pipelines can be put into operation, or two or three pipelines can be put into operation simultaneously, thereby obtaining the cracking product yield after the process combination in one step. Attached Figure Description

[0081] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0082] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0083] Figure 1 This is a flowchart of the crude oil steam cracking method described in this invention;

[0084] Figure 2 This is a schematic diagram of the crude oil processing unit in the crude oil steam cracking evaluation system of the present invention;

[0085] Figure 3 This is a schematic diagram of the structure of the cracking and product separation device in the crude oil steam cracking evaluation system of the present invention.

[0086] Explanation of reference numerals in the attached figures:

[0087] 100. Raw material tank; 101. Agitator; 102. Raw material tank heater; 103. First metering device; 104. Raw material tank support; 105. Raw material supply pipe; 106. Hose section; 107. Check valve; 108. Raw material pump; 109. Raw material preheater; 110. Raw material tank discharge valve;

[0088] 200. First water tank; 201. Second metering device; 202. Steam supply pipe; 203. First water pump; 204. Vaporizer; 205. First water tank discharge valve;

[0089] 300. First flash tank; 301. First flash heater; 302. First vapor phase distillation pipe; 303. Second flash heater; 304. First flash pressure control valve; 305. First liquid phase distillation pipe; 306. First liquid phase discharge pipe; 307. First flash tank discharge valve; 308. First flash tank conveying valve; 309. First flash tank discharge valve; 310. First heating coil; 311. First heating wire; 312. Pressure gauge;

[0090] 400. Second flash tank; 401. Second vapor phase distillation pipe; 402. Second vapor phase distillation discharge pipe; 403. Second flash tank vapor phase discharge valve; 404. Second flash tank vapor phase conveying valve; 405. Second flash tank vapor phase control valve; 406. First flow meter; 407. Second flash tank vapor phase discharge valve; 408. Second liquid phase distillation pipe; 409. Second liquid phase distillation discharge pipe; 410. Second flash tank liquid phase discharge valve; 411. Second flash tank liquid phase conveying valve; 412. Second flow meter; 413. Connecting valve; 414. Second flash tank liquid phase discharge valve; 415. Fourth liquid phase distillation pipe; 416. Second heating coil; 417. Second heating wire;

[0091] 500. Buffer tank; 501. Third liquid phase fraction pipe; 502. Third liquid phase fraction discharge pipe; 503. Buffer tank liquid phase discharge valve; 504. Buffer tank liquid phase conveying valve; 505. Third flow meter; 506. Buffer tank liquid phase discharge valve; 507. Third heating coil; 508. Third heating wire;

[0092] 600. Pyrolysis heating furnace; 601. First convection section furnace tube; 602. First radiant section furnace tube; 603. Second convection section furnace tube; 604. Second radiant section furnace tube; 605. Third convection section furnace tube; 606. Third radiant section furnace tube;

[0093] 700. Second water tank; 701. Third metering device; 702. First water supply pipe; 703. Second water tank discharge valve; 704. Second water pump; 705. Third water tank; 706. Fourth metering device; 707. Second water supply pipe; 708. Third water tank discharge valve; 709. Third water pump; 710. Fourth water tank; 711. Fifth metering device; 712. Third water supply pipe; 713. Fourth water tank discharge valve; 714. Fourth water pump;

[0094] 800. Cooling tank; 801. First pyrolysis gas pipe; 802. First quench cooler; 803. Second quench cooler; 804. Cooling tank outlet cooling pipe; 805. Cooling coil; 806. Cooling tank discharge pipe; 807. Cooling tank discharge valve; 808. Cryogenic tank; 809. Second pyrolysis gas pipe; 810. Cryogenic tank inlet cooling pipe; 811. Cryogenic tank outlet cooling pipe; 812. Pressure regulating valve; 813. Gas buffer bottle; 814. Fourth flow meter; 815. Cryogenic coil; 816. Cryogenic tank discharge pipe; 817. Cryogenic tank discharge valve;

[0095] 900. Main gas supply pipe; 901. Main gas supply pipe control valve; 902. Main gas supply pipe flow meter; 903. First gas supply pipe; 904. Second gas supply pipe; 905. Third gas supply pipe; 906. Branch gas supply pipe control valve; 907. Branch gas supply pipe flow meter. Detailed Implementation

[0096] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0097] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0098] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0099] Implementation Method 1:

[0100] like Figures 1 to 3 As shown, the present invention provides a crude oil steam cracking method, which includes the following steps:

[0101] Step S1: After mixing crude oil with steam, the mixture enters the first flash tank 300 for first flash separation to obtain the first gas phase fraction and the first liquid phase fraction;

[0102] Step S2: The first gas phase fraction is passed into the second flash tank 400 for second flash separation to obtain the second gas phase fraction and the second liquid phase fraction. At the same time, the first liquid phase fraction is passed into the buffer tank 500 to obtain the third liquid phase fraction.

[0103] Step S3: The second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction are respectively fed into the convection section of the pyrolysis heating furnace 600 for heating, and then respectively enter the radiation section of the pyrolysis heating furnace 600 for pyrolysis;

[0104] Step S4: Cool the pyrolysis gas generated in the pyrolysis heating furnace 600 from the second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction.

[0105] The crude oil steam cracking method of the present invention divides crude oil into three fractions—light components, intermediate components, and heavy components—according to cracking requirements, and performs independent cracking on the above fractions, which can quickly complete the steam cracking of crude oil and improve the yield of various products.

[0106] The following section will describe in detail the steps of the crude oil steam cracking method described in this invention.

[0107] In step S1, the preheated crude oil and steam are mixed through a pipeline and then introduced into the first flash tank 300. Under certain temperature and pressure, the mixture generates a first gas phase fraction and a first liquid phase fraction in the first flash tank 300. The two fractions can be discharged from the gas phase outlet and the liquid phase outlet of the first flash tank 300, respectively.

[0108] In step S2, following step S1, after the mixture completes one flash separation, the separated first gaseous fraction is piped into the second flash tank 400. Under certain temperature and pressure, the first gaseous fraction is fractionated into a second gaseous fraction and a second liquid fraction in the second flash tank 400. The second gaseous fraction and the second liquid fraction can be discharged from the gas phase outlet and liquid phase outlet of the second flash tank 400, respectively. Simultaneously, the first liquid fraction separated in the first flash separation is piped into the buffer tank 500. Under certain temperature and pressure, the first liquid fraction is buffered in the buffer tank 500 to form a third liquid fraction, which can flow out from the outlet of the buffer tank 500.

[0109] In step S3, following step S2 above, after completing the secondary flash separation of the gas phase and the buffering of the liquid phase, the obtained second gas phase fraction, second liquid phase fraction and third liquid phase fraction are respectively fed into the cracking heating furnace 600 through pipelines. The three fractions can be heated and cracked in the cracking heating furnace 600. Each fraction first enters the furnace tube in the convection section of the cracking heating furnace 600 for heating, and then enters the furnace tube in the radiation section of the cracking heating furnace 600 for cracking to generate cracked gas.

[0110] In step S4, following step S3 above, after completing the heating and cracking operation of each fraction, the cracked gas generated by each fraction is cooled; throughout the experiment, the experimental conditions can be changed, and the obtained cracking results can be analyzed and evaluated, providing technical reference for the separation and cracking of crude oil fractions in industrial production.

[0111] The preferred embodiments of the crude oil steam cracking method of the present invention will be described below.

[0112] According to one embodiment of the present invention, such as Figure 3As shown, a water supply unit is connected to the convection section inside the pyrolysis heating furnace 600; within the convection section of the pyrolysis heating furnace 600, the second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction are mixed with water and / or steam supplied by the water supply unit, respectively.

[0113] The water supply unit can supply water to the furnace tubes in the convection section of the pyrolysis heating furnace 600. The water generates steam in the furnace tubes in the convection section and mixes with the fractions entering the furnace tubes in the convection section, so that the fractions can be fully pyrolyzed when they enter the radiation section.

[0114] According to one embodiment of the present invention, such as Figure 3 As shown, a gas supply unit is connected between the convection section and the radiation section of the cracking furnace 600; after the cracking of crude oil is completed, the air in the gas supply unit enters the radiation section of the cracking furnace 600 for coking.

[0115] The steam cracking reaction temperature reaches over 800 degrees Celsius. Carbon deposits generated during the cracking of raw materials can clog pipelines. To ensure continuous equipment operation, high-temperature air is needed to remove these carbon deposits. Furthermore, crude oil steam cracking is more prone to carbon buildup. Therefore, an air supply unit is installed. After the crude oil cracking is complete, air is introduced into the radiant section within the cracking furnace 600 through this unit. Under high-temperature conditions, the sidewalls of the pipelines are burned off.

[0116] The above only describes the crude oil steam cracking method in conjunction with the main equipment. The following text will provide a crude oil steam cracking evaluation system. This system, combined with the crude oil steam cracking method provided in Implementation Method 1, can evaluate crude oil steam cracking and provide technical reference for the industrialization of crude oil steam cracking.

[0117] Implementation Method Two:

[0118] like Figure 2 and Figure 3 As shown, the present invention provides a crude oil steam cracking evaluation system, which includes a crude oil processing unit and a cracking and product separation unit connected together.

[0119] The crude oil processing unit includes a first flash unit, a second flash unit, and a buffer unit; the inlet of the first flash unit is connected to a raw material supply unit and a steam supply unit; the inlet of the second flash unit is connected to the gas phase outlet of the first flash unit; and the inlet of the buffer unit is connected to the liquid phase outlet of the first flash unit.

[0120] The pyrolysis and product separation device includes a pyrolysis heating furnace 600, three sets of liquid supply units, and a cooling unit. The pyrolysis heating furnace 600 is equipped with three sets of parallel convection sections and radiation sections, which are connected to each other. The three sets of convection sections are respectively connected to the gas phase outlet of the second flash evaporation unit, the liquid phase outlet of the second flash evaporation unit, and the liquid phase outlet of the buffer unit. The three sets of liquid supply units are respectively connected to the inlets of the three sets of convection sections. The cooling unit is connected to the outlets of the three sets of radiation sections.

[0121] The following section will provide a detailed description of the specific structure of each part of the crude oil steam cracking evaluation system described in this invention, as well as the pipeline connection relationships between each part.

[0122] Crude oil processing units have feedstock supply units, such as Figure 2 As shown, the raw material supply unit includes a raw material tank 100, a first metering device 103, and a raw material supply pipe 105. The raw material tank 100 is used to store crude oil and is equipped with a stirrer 101 and a raw material tank heater 102. The raw material tank 100 is placed on the first metering device 103 via a raw material tank support 104. The raw material supply pipe 105 connects the raw material tank 100 and the first flash evaporation unit, and is equipped with a raw material pump 108 and a raw material preheater 109.

[0123] Specifically, the raw material tank 100 contains crude oil. A raw material tank support 104 is provided on the outside of the raw material tank 100 to fix it in place. The support 104 is placed on a first metering device 103 to monitor changes in the quality of the crude oil within the raw material tank 100. An agitator 101 is installed inside the raw material tank 100. The agitator 101 has a motor-driven stirring paddle that is inserted into the raw material tank 100 and agitates the crude oil under the drive of the motor. A raw material tank heater 102 is also installed inside the raw material tank 100 to heat the crude oil. The agitation action of the agitator 101 and the heating action of the heater prevent the crude oil from settling or clumping inside the raw material tank 100. The bottom outlet of the raw material tank 100 is connected to a raw material supply pipe 105, on which a raw material pump 108 is used to drive the flow of crude oil, and a raw material preheater 109 is used to heat the crude oil in the pipe. A section of flexible hose 106 is also provided on the raw material supply pipe 105 to facilitate the adjustment of the position of the raw material tank 100. A raw material tank discharge valve 110 is provided on the raw material supply pipe 105 to control the opening and closing of the pipe. A one-way valve 107 is provided on the raw material supply pipe 105 to prevent the backflow of crude oil.

[0124] The crude oil processing unit has a steam supply unit, such as Figure 2As shown, the steam supply unit includes a first water tank 200, a second metering device 201, and a steam supply pipe 202. The first water tank 200 is used to store water; the first water tank 200 is placed on the second metering device 201; the steam supply pipe 202 connects the first water tank 200 and the first flash evaporation unit, and the steam supply pipe 202 is equipped with a first water pump 203 and a vaporizer 204.

[0125] Specifically, the first water tank 200 contains water (usually purified water), and the second metering device 201 is used to monitor changes in the quality of the water in the first water tank 200. A steam supply pipe 202 is connected to the bottom outlet of the first water tank 200, and a first water pump 203 on it drives the flow of fluid within the pipe. A vaporizer 204 vaporizes the water in the pipe into steam. A flexible hose section 106 is also provided on the steam supply pipe 202 to facilitate adjustment of the position of the first water tank 200. A discharge valve 205 is provided on the steam supply pipe 202 to control the opening and closing of the pipe, and a one-way valve 107 is provided on the steam supply pipe 202 to prevent backflow of fluid within the pipe.

[0126] The crude oil processing unit has a first flash unit, such as Figure 2 As shown, the first flash unit includes a first flash tank 300 and a first flash heater 301. The first flash tank 300 has an inlet, a gas phase outlet and a liquid phase outlet. The inlet of the first flash tank 300 is connected to the raw material supply unit and the steam supply unit. The first flash heater 301 is installed on the pipe connected to the inlet of the first flash tank 300.

[0127] Specifically, the outlets of the raw material supply pipe 105 and the steam supply pipe 202 are both connected to the inlet of the first flash tank 300. The raw material supply pipe 105 and the steam supply pipe 202 share a common pipe section at the inlet of the first flash tank 300, meaning that the crude oil and steam are mixed before entering the first flash tank 300. The first flash heater 301 is installed on this common pipe section to heat the mixed crude oil and steam. Under certain temperature and pressure, the mixture produces a first vapor phase fraction and a first liquid phase fraction in the first flash tank 300. The two fractions can be discharged from the vapor phase outlet and the liquid phase outlet of the first flash tank 300, respectively. The vapor phase outlet of the first flash tank 300 is located at the top of the tank and is connected to the first vapor phase fraction pipe 302. The liquid phase outlet of the second flash tank 400 is located at the bottom of the tank and is connected to the first liquid phase fraction pipe 305.

[0128] Furthermore, such as Figure 2 As shown, the first liquid phase distillation pipe 305 is equipped with a first flash tank discharge valve 307 and a first flash tank delivery valve 308, which are used to control the opening and closing of the first liquid phase distillation pipe 305.

[0129] Better, such as Figure 2As shown, the first flash tank 300 is equipped with a first heating coil 310, and a first heating wire 311 is fitted around the outer periphery of the first flash tank 300. The first heating coil 310 can heat the mixture inside the tank to a predetermined temperature, and the first heating wire 311 can keep the first flash tank 300 warm. A pressure gauge 312 is provided on the first flash tank 300 to monitor the pressure inside the first flash tank 300.

[0130] The crude oil processing unit has a second flash unit, such as Figure 2 As shown, the second flash evaporation unit includes a second flash tank 400 and a second flash heater 303. The second flash tank 400 has an inlet, a vapor phase outlet, and a liquid phase outlet. The inlet of the second flash tank 400 is connected to the vapor phase outlet of the first flash tank 300 via a first vapor phase distillation pipe 302. The vapor phase outlet of the second flash tank 400 is connected to a second vapor phase distillation pipe 401, and the liquid phase outlet of the second flash tank 400 is connected to a second liquid phase distillation pipe 408. The second flash heater 303 is mounted on the first vapor phase distillation pipe 302.

[0131] Specifically, such as Figure 2 As shown, the first vapor phase distillation pipe 302 is connected between the vapor phase outlet of the first flash tank 300 and the inlet of the second flash tank 400. The first vapor phase distillate generated in the first flash tank 300 can enter the second flash tank 400 through the first vapor phase distillation pipe 302. The first vapor phase distillation pipe 302 is equipped with a second flash heater 303 and a first flash pressure control valve 304. The second flash heater 303 is used to heat the first vapor phase distillate that is about to enter the second flash tank 400, and the first flash pressure control valve is used to control the pressure in the first flash tank 300. The first vapor fraction is fractionated into a second vapor fraction and a second liquid fraction in the second flash tank 400. The second vapor fraction and the second liquid fraction can be discharged from the vapor outlet and the liquid outlet of the second flash tank 400, respectively. The vapor outlet of the second flash tank 400 is located at the top of the tank and is connected to the second vapor fraction pipe 401. The liquid outlet of the second flash tank 400 is located at the bottom of the tank and is connected to the second liquid fraction pipe 408.

[0132] Furthermore, such as Figure 2 As shown, along the flow direction of the fluid in the second gas phase distillation pipe 401, the second gas phase distillation pipe 401 is sequentially equipped with a second flash tank gas phase discharge valve 403, a second flash tank gas phase delivery valve 404, a first flow meter 406, a second flash tank gas phase control valve 405, and a one-way valve 107. The second flash tank gas phase discharge valve 403, the second flash tank gas phase delivery valve 404, and the second flash tank gas phase control valve 405 are used to control the opening, closing, and opening degree of the second gas phase distillation pipe 401; the first flow meter 406 is used to monitor the flow rate of the fluid in the second gas phase distillation pipe 401; and the one-way valve 107 is used to prevent backflow of the fluid in the second gas phase distillation pipe 401.

[0133] Along the flow direction of the fluid within the second liquid phase distillation pipe 408, the second liquid phase distillation pipe 408 is sequentially equipped with a second flash tank liquid phase discharge valve 410, a second flash tank liquid phase delivery valve 411, a second flow meter 412, and a one-way valve 107. The second flash tank liquid phase discharge valve 410 and the second flash tank liquid phase delivery valve 411 are used to control the opening and closing of the second liquid phase distillation pipe 408; the second flow meter 412 is used to monitor the flow rate of the fluid within the second liquid phase distillation pipe 408; and the one-way valve 107 is used to prevent backflow of the fluid within the second liquid phase distillation pipe 408.

[0134] Better, such as Figure 2 As shown, the second flash tank 400 is equipped with a second heating coil 416, and a second heating wire 417 is fitted around the outer periphery of the second flash tank 400. The second heating coil 416 can heat the first vapor fraction in the tank to a predetermined temperature, and the second heating wire 417 can keep the second flash tank 400 warm. A pressure gauge 312 is provided on the second flash tank 400 to monitor the pressure inside the second flash tank 400.

[0135] Crude oil processing units have buffer units, such as Figure 2 As shown, the buffer unit includes a buffer tank 500. The buffer tank 500 has a first inlet and a liquid phase outlet. The first inlet of the buffer tank 500 is connected to the liquid phase outlet of the first flash tank 300 through a first liquid phase distillation pipe 305, and the liquid phase outlet of the buffer tank 500 is connected to a third liquid phase distillation pipe 501.

[0136] Specifically, such as Figure 2 As shown, the first liquid phase distillation pipe 305 is connected between the liquid phase outlet of the first flash tank 300 and the first inlet of the buffer tank 500. The first liquid phase distillate generated in the first flash tank 300 can enter the buffer tank 500 through the first liquid phase distillation pipe 305 for buffering to form a third liquid phase distillate. The third liquid phase distillate can flow out from the liquid phase outlet of the buffer tank 500. The liquid phase outlet of the buffer tank 500 is located at the bottom of the tank and is connected to the third liquid phase distillation pipe 501.

[0137] Furthermore, such as Figure 2 As shown, along the flow direction of the fluid in the third liquid phase distillation pipe 501, the third liquid phase distillation pipe 501 is sequentially equipped with a buffer tank liquid phase discharge valve 503, a buffer tank liquid phase delivery valve 504, a third flow meter 505, and a one-way valve 107. The buffer tank liquid phase discharge valve 503 and the buffer tank liquid phase delivery valve 504 are used to control the opening and closing of the third liquid phase distillation pipe 501, the third flow meter 505 is used to monitor the flow rate of the fluid in the third liquid phase distillation pipe 501, and the one-way valve 107 is used to prevent backflow of the fluid in the third liquid phase distillation pipe 501.

[0138] Better, such as Figure 2 As shown, the buffer tank 500 is equipped with a third heating coil 507, and a third heating wire 508 is fitted around the outer periphery of the buffer tank 500. The third heating coil 507 can heat the first liquid phase fraction in the tank to a predetermined temperature, and the third heating wire 508 can keep the buffer tank 500 warm. A pressure gauge 312 is provided on the buffer tank 500 to monitor the pressure inside the buffer tank 500.

[0139] According to one embodiment of the present invention, such as Figure 2 As shown, the buffer tank 500 also has a second inlet, which is connected to the liquid phase outlet of the second flash tank 400 via a fourth liquid phase distillation pipe 415.

[0140] Specifically, such as Figure 2 As shown, the second inlet of the buffer tank 500 is located at the top of the tank and is connected to a fourth liquid phase distillation pipe 415. The other end of the fourth liquid phase distillation pipe 415 is connected to the second liquid phase distillation pipe 408, and is connected between the second flash tank liquid phase discharge valve 410 and the second flash tank liquid phase delivery valve 411 via a connecting valve 413. The second liquid phase distillate in the second flash tank 400 can flow into the buffer tank 500 through a portion of the second liquid phase distillation pipe 408 and the third liquid phase distillation pipe 501.

[0141] According to one embodiment of the present invention, such as Figure 2 As shown, a first liquid phase distillation pipe 305 is connected to a first liquid phase distillation pipe 306; a second gas phase distillation pipe 401 is connected to a second gas phase distillation pipe 402; a fourth liquid phase distillation pipe 415 is connected to a second liquid phase distillation pipe 409; and a third liquid phase distillation pipe 501 is connected to a third liquid phase distillation pipe 502.

[0142] Specifically, such as Figure 2As shown, the first liquid phase fraction discharge pipe 306 is connected between the first flash tank discharge valve 307 and the first flash tank conveying valve 308. The first liquid phase fraction generated in the first flash tank 300 can be discharged through the first liquid phase fraction discharge pipe 306, thus preventing it from entering the buffer tank 500. The first liquid phase fraction discharge pipe 306 is equipped with a first flash tank discharge valve 309, which is used to control the opening and closing of the first liquid phase fraction discharge pipe 306. The second vapor phase fraction discharge pipe 402 is connected to the second flash tank vapor phase discharge valve 403 and the second flash tank vapor phase conveying valve 404. The second vapor phase fraction generated in the second flash tank 400 can be discharged through the second vapor phase fraction discharge pipe 402, thus preventing it from continuing to be conveyed forward through the second vapor phase fraction pipe 401. The second vapor phase fraction discharge pipe 402 is equipped with a second flash tank vapor phase discharge valve 407, which is used to control the opening and closing of the second vapor phase fraction discharge pipe 402. The second liquid phase fraction discharge pipe 409 is connected to the fourth liquid phase fraction pipe 415. The second liquid phase fraction generated in the second flash tank 400 can be discharged through the second liquid phase fraction discharge pipe 409, thus bypassing the second liquid phase fraction pipe 408 for further forward transport. The second liquid phase fraction discharge pipe 409 is equipped with a second flash tank liquid phase discharge valve 414 for controlling the opening and closing of the second liquid phase fraction discharge pipe 409. The third liquid phase fraction discharge pipe 502 is located between the buffer tank liquid phase discharge valve 503 and the buffer tank liquid phase transport valve 504. The third liquid phase fraction generated in the buffer tank 500 can be discharged through the third liquid phase fraction discharge pipe 502, thus bypassing the third liquid phase fraction pipe 501 for further forward transport. The third liquid phase fraction discharge pipe 502 is equipped with a buffer tank liquid phase discharge valve 506 for controlling the opening and closing of the third liquid phase fraction discharge pipe 502.

[0143] The pyrolysis and product separation apparatus of the present invention includes a pyrolysis heating furnace 600, such as... Figure 2 and Figure 3 As shown, the pyrolysis heating furnace 600 includes three sets of convection sections and heat exchange sections arranged in parallel.

[0144] Specifically, such as Figure 2 and Figure 3 As shown, the first convection section furnace tube 601 is connected to the first radiation section furnace tube 602, and the first convection section furnace tube 601 is connected to the second gas phase distillation tube 401; the second convection section furnace tube 603 is connected to the second radiation section furnace tube 604, and the second convection section furnace tube 603 is connected to the second liquid phase distillation tube 408; the third convection section furnace tube 605 is connected to the third radiation section furnace tube 606, and the third convection section furnace tube 605 is connected to the third liquid phase distillation tube 501.

[0145] The pyrolysis and product separation apparatus of the present invention includes a pyrolysis heating furnace 600, such as... Figure 3As shown, the three sets of liquid supply units include a second water tank 700, a third water tank 705, and a fourth water tank 710. The second water tank 700 is placed on the third metering device 701 and is connected to the first convection section furnace tube 601 via a first water supply pipe 702. The third water tank 705 is placed on the fourth metering device 706 and is connected to the second convection section furnace tube 603 via a second water supply pipe 707. The fourth water tank 710 is placed on the fifth metering device 711 and is connected to the third convection section furnace tube 605 via a third water supply pipe 712.

[0146] Specifically, such as Figure 2 and Figure 3 As shown, the second water tank 700, the third water tank 705, and the fourth water tank 710 all contain water. The third metering device 701, the fourth metering device 706, and the fifth metering device 711 are used to monitor the quality changes of the water in the second water tank 700, the third water tank 705, and the fourth water tank 710, respectively. The bottom outlet of the second water tank 700 is connected to a first water supply pipe 702, and the other end of the first water supply pipe 702 is connected to the inlet of the first convection section furnace tube 601 for supplying water to the first convection section furnace tube 601. The first water supply pipe 702 is equipped with a second water tank discharge valve 703, a hose section 106, and a second water pump 704. The second water tank discharge valve 703 is used to control the opening and closing of the first water supply pipe 702, the hose section 106 facilitates the adjustment of the position of the second water tank 700, and the second water pump 704 is used to drive the flow of water in the pipe. The bottom outlet of the third water tank 705 is connected to a second water supply pipe 707. The other end of the second water supply pipe 707 is connected to the inlet of the second convection section furnace tube 603 for supplying water to the second convection section furnace tube 603. The second water supply pipe 707 is equipped with a third water tank discharge valve 708, a hose section 106 and a third water pump 709. The third water tank discharge valve 708 is used to control the opening and closing of the second water supply pipe 707. The hose section 106 facilitates the adjustment of the position of the third water tank 705. The third water pump 709 is used to drive the flow of water in the pipe. The bottom outlet of the fourth water tank 710 is connected to the third water supply pipe 712. The other end of the third water supply pipe 712 is connected to the inlet of the third convection section furnace tube 605 for supplying water to the third convection section furnace tube 605. The third water supply pipe 712 is equipped with a fourth water tank discharge valve 713, a hose section 106 and a fourth water pump 714. The fourth water tank discharge valve 713 is used to control the opening and closing of the third water supply pipe 712. The hose section 106 facilitates the adjustment of the position of the fourth water tank 710. The fourth water pump 714 is used to drive the flow of water in the pipe.

[0147] like Figure 2 and Figure 3As shown, the first convection section furnace tube 601 is connected to the second vapor phase distillation tube 401. The second vapor phase distillation mixes with the steam generated in the first convection section furnace tube 601 and enters the first radiant section furnace tube 602 for steam cracking. The second convection section furnace tube 603 is connected to the second liquid phase distillation tube 408. The second liquid phase distillation mixes with the steam generated in the second convection section furnace tube 603 and enters the second radiant section furnace tube 604 for steam cracking to produce cracked gas. The third convection section furnace tube 605 is connected to the third liquid phase distillation tube 501. The third liquid phase distillation mixes with the steam generated in the third convection section furnace tube 605 and enters the third radiant section furnace tube 606 for steam cracking to produce cracked gas.

[0148] The pyrolysis and product separation apparatus of the present invention includes a pyrolysis heating furnace 600, such as... Figure 3 As shown, the cooling unit includes a cooling tank 800 and a cryogenic tank 808. The inlet of the cooling tank 800 is connected to the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 via a first pyrolysis gas pipe 801; the inlet of the cryogenic tank 808 is connected to the outlet of the cooling tank 800, and the outlet of the cryogenic tank 808 is connected to a second pyrolysis gas pipe 809.

[0149] Specifically, such as Figure 3 As shown, the cooling tank 800 is equipped with a cooling coil 805, and the cryogenic tank 808 is equipped with a cryogenic coil 815. The cooling coil 805 and the cryogenic coil 815 are used for primary cooling and cryogenic cooling of the pyrolysis gas. The first pyrolysis gas pipe 801 is connected between the inlet of the pyrolysis heating furnace 600 and the cooling tank 800. The pyrolysis gas generated in the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 can all enter the cooling tank 800 through the first pyrolysis gas pipe 801 for cooling. Along the flow direction of the pyrolysis gas in the first pyrolysis gas pipe 801, the first quench cooler 802 and the second quench cooler 803 are sequentially provided on the first pyrolysis gas pipe 801. The inlet of the cryogenic tank 808 is connected to the outlet of the cooling tank 800. The outlet of the cryogenic tank 808 is connected to a second pyrolysis gas pipe 809. A cooling tank outlet cooling pipe 804 is fitted onto the pipe connected to the outlet of the cooling tank 800. A cryogenic tank inlet cooling pipe 810 is fitted onto the pipe connected to the inlet of the cryogenic tank 808. A cryogenic tank outlet cooling pipe 811 is fitted onto the pipe connected to the outlet of the cryogenic tank 808. Along the flow direction of the pyrolysis gas within the second pyrolysis gas pipe 809, a pressure regulating valve 812, a gas buffer bottle 813, and a fourth flow meter 814 are sequentially installed on the second pyrolysis gas pipe 809. The pressure regulating valve 812 is used to adjust the pressure within the cooling tank 800 and the cryogenic tank 808. The gas buffer bottle 813 is used to buffer the pyrolysis gas, and the fourth flow meter 814 is used to monitor the flow rate of the cooled pyrolysis gas.

[0150] According to one embodiment of the present invention, such as Figure 3As shown, the bottom of the cooling tank 800 is connected to the cooling tank discharge pipe 806; the bottom of the cryogenic tank 808 is connected to the cryogenic tank discharge pipe 816.

[0151] Specifically, such as Figure 3 As shown, the cooling tank discharge pipe 806 is used to discharge the condensed products generated therein, and a cooling tank discharge valve 807 is provided on the cooling tank discharge pipe 806. The cooling tank discharge valve 807 is used to control the opening and closing of the cooling tank discharge pipe 806. The cryogenic tank discharge pipe 816 is used to discharge the condensed products generated therein, and a cryogenic tank discharge valve 817 is provided on the cryogenic tank discharge pipe 816. The cryogenic tank discharge valve 817 is used to control the opening and closing of the cryogenic tank discharge pipe 816.

[0152] The pyrolysis and product separation apparatus of this invention also includes a gas supply unit, which comprises a main gas supply pipe 900 and three branch gas supply pipes connected to the main gas supply pipe 900. After the crude oil pyrolysis is completed, the air in the gas supply unit enters the radiant section of the pyrolysis heating furnace 600 for coking to prevent pipe blockage.

[0153] Specifically, such as Figure 3 As shown, along the air flow direction within the main gas supply pipe 900, the main gas supply pipe 900 is equipped with a main gas supply pipe control valve 901, a main gas supply pipe flow meter 902, and a one-way valve 107. The main gas supply pipe control valve 901 is used to control the opening and closing of the main gas supply pipe 900, the main gas supply pipe flow meter 902 is used to monitor the air flow rate within the pipe, and the one-way valve 107 is used to prevent backflow of air within the pipe. Three gas supply branch pipes include a first gas supply pipe 903, a second gas supply pipe 904, and a third gas supply pipe 905. The first gas supply pipe 903 connects to the pipe where the first convection section furnace tube 601 and the second vapor phase distillation pipe 401 merge; the second gas supply pipe 904 connects to the pipe where the second convection section furnace tube 603 and the second liquid phase distillation pipe 408 merge; and the third gas supply pipe 905 connects to the pipe where the third convection section furnace tube 605 and the third liquid phase distillation pipe 501 merge. Along the air flow direction in the gas supply branch pipe, each gas supply branch pipe is equipped with a gas supply branch pipe control valve 906, a gas supply branch pipe flow meter 907, and a one-way valve 107.

[0154] Implementation Method 3:

[0155] The present invention also provides a crude oil vapor cracking evaluation method, which is implemented using the crude oil vapor cracking evaluation system as described in Embodiment 2. The crude oil vapor cracking evaluation method includes the following steps:

[0156] Step S10: Start the pyrolysis and product separation device. When the pyrolysis heating furnace 600 is heated to the predetermined temperature and the cooling unit is cooled to the predetermined temperature, open the liquid supply unit to supply water into the pyrolysis heating furnace 600.

[0157] Step S20: Start the crude oil processing unit to raise the temperature of the first flash unit, the second flash unit and the buffer unit to the predetermined temperature;

[0158] Step S30: Start the raw material supply unit and steam supply unit to supply materials to the first flash unit for preliminary experiment;

[0159] Step S40: Conduct a formal test and record the supply and product quantities of each raw material before and after the formal test;

[0160] Step S50: After the cracking and product separation unit and the crude oil processing unit have cooled down, shut down the cracking and product separation unit and the crude oil processing unit.

[0161] The following section will describe in detail the operation process of each step in the crude oil steam cracking evaluation method of the present invention.

[0162] In step S10, the pyrolysis and product separation device is started: the main gas supply pipe 900 and its branch gas supply pipes are closed, and the pyrolysis heating furnace 600 is started to heat the first convection section furnace tube 601, the first radiation section furnace tube 602, the second convection section furnace tube 603, the second radiation section furnace tube 604, the third convection section furnace tube 605, and the third radiation section furnace tube 606; the first quench cooler 802 and the second quench cooler 803 on the first pyrolysis gas pipe 801 are started for cooling; the cooling tank 800, the cooling coil 805 inside the cooling tank 800, and the cooling pipe 804 at the outlet of the cooling tank are started for cooling; the cryogenic tank inlet cooling pipe 810, the cryogenic tank 808, the cryogenic coil 815 inside the cryogenic tank 808, and the cryogenic tank outlet cooling pipe 811 are started for cooling. The controlled temperatures of the first convection section furnace tube 601, the second convection section furnace tube 603, and the third convection section furnace tube 605 are all 500℃~550℃, and the controlled temperatures of the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 are all 710℃~1000℃. The controlled temperatures of the first quench cooler 802, the second quench cooler 803, the cooling tank 800, the cooling coil 805, the cooling tank outlet cooling pipe 804, the cryogenic tank inlet cooling pipe 810, and the cryogenic tank outlet cooling pipe 811 are all 5℃~30℃, and the controlled temperatures of the cryogenic tank 808 and the cryogenic coil 815 are both 0℃~5℃.

[0163] Furthermore, when the temperatures in the first convection section furnace tube 601 and / or the second convection section furnace tube 603 and / or the third convection section furnace tube 605, the first radiant section furnace tube 602 and / or the second radiant section furnace tube 604 and / or the third radiant section furnace tube 606 are all close to 500°C, the feeding of the second water tank 700, the third water tank 705 and the fourth water tank 710 in the pyrolysis and product separation device is started.

[0164] In step S20, the crude oil processing unit is started: the vaporizer 204, the feed preheater 109, the first flash heater 301, the first heating wire 311 outside the first flash tank 300 and the first heating coil 310 inside it, the second flash heater 303, the second heating wire 417 outside the second flash tank 400 and the second heating coil 416 inside it, the third heating wire 508 outside the buffer tank 500 and the third heating coil 507 inside it are heated to raise the temperature, the second vapor phase fraction discharge pipe 402, the second liquid phase fraction discharge pipe 409, the third liquid phase fraction discharge pipe 502, and the connecting valve 413 are closed, and the second vapor phase fraction pipe 401 connected to the top of the second flash tank 400 is opened. The control temperatures of vaporizer 204 and raw material preheater 109 are both 180℃~350℃, the control temperature of first flash heater 301 is 220℃~380℃, the control temperature of second flash heater 303 is 100℃~220℃, the control temperature in buffer tank 500 is 100℃~380℃, the control temperature in first flash tank 300 is ±20℃ of the control temperature of first flash heater 301, and the control temperature in second flash tank 400 is ±20℃ of the control temperature of second flash heater 303.

[0165] In step S30, a preliminary experiment is conducted: After all the furnace tubes in the radiant sections of the pyrolysis and product separation unit reach the set temperature, the feed tank 100 and the first water tank 200 in the crude oil processing unit are started, maintaining the feed rate of the feed tank 100 to the feed rate of the first water tank 200 at a ratio of 1:0 to 1. Then, the second flash tank vapor phase delivery valve 404 on the second vapor phase distillation pipe 401, the second flash tank liquid phase delivery valve 411 on the second liquid phase distillation pipe 408, and the buffer tank liquid phase delivery valve 504 on the third liquid phase distillation pipe 501 are temporarily closed, i.e., the pipeline between the crude oil processing unit and the pyrolysis and product separation unit is closed. The second vapor phase distillation discharge pipe 402, the second liquid phase distillation discharge pipe 409, and the third liquid phase distillation discharge pipe 502 are opened. The change in the mass of the feed tank 100 and the mass of the product in the corresponding discharge pipe is measured per unit time for flash calibration. After the flash calibration is completed, the valve positions are restored. Then, adjust the temperature of each radiant section furnace tube in the pyrolysis and product separation device, set the feed rate of the water pump on the corresponding water supply pipe in the pyrolysis and product separation device, and start the second flash tank 400 and buffer tank 500 to feed materials into the pyrolysis and product separation device.

[0166] In step S40, after the preliminary test stabilizes for 5-10 minutes, the formal test is conducted: the cooling tank 800 and cryogenic tank 808 in the pyrolysis and product separation device are emptied, and the readings of the fourth flow meter 814, the first metering device 103, the second metering device 201, the third metering device 701, the fourth metering device 706, and the fifth metering device 711 are recorded before the formal test begins. After the formal test is completed, the liquid phase products in the cooling tank 800 and cryogenic tank 808 are collected, and the readings of the fourth flow meter 814, the first metering device 103, the second metering device 201, the third metering device 701, the fourth metering device 706, and the fifth metering device 711 are recorded again. The device is kept in operation and serves as a preliminary test for the next test.

[0167] In step S50, the device is shut down: the feed into the raw material tank 100 of the crude oil processing unit is stopped, the heating of all parts of the crude oil processing unit is stopped, the second vapor phase distillation pipe 401, the second liquid phase distillation pipe 408, and the third liquid phase distillation pipe 501 are closed, and the second vapor phase distillation discharge pipe 402, the second liquid phase distillation discharge pipe 409, and the third liquid phase distillation discharge pipe 502 are opened for discharge. When the temperature inside the first flash tank 300 is ≤110℃, the feed into the first water tank 200 of the crude oil processing unit is stopped; after the first flash tank 300, the second flash tank 400, and the buffer tank 500 are all emptied, the second vapor phase distillation discharge pipe 402, the second liquid phase distillation discharge pipe 409, and the third liquid phase distillation discharge pipe 502 are closed to stop discharge. Stop heating the pyrolysis and product separation device. When the temperatures of the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 are all no higher than 300°C, stop feeding the second water tank 700, the third water tank 705, and the fourth water tank 710 in the pyrolysis and product separation device. After emptying the cooling tank 800 and the cryogenic tank 808, close the cooling tank discharge pipe 806 and the cryogenic tank discharge pipe 816.

[0168] According to one embodiment of the present invention, the pyrolysis and product separation apparatus further includes a gas supply unit for introducing air into the pyrolysis heater 600; the crude oil steam pyrolysis evaluation method further includes the following steps:

[0169] Step S60: After the cracking and product separation unit and the crude oil processing unit are shut down, the cracking and product separation unit is restarted. When the cracking furnace 600 is heated to the predetermined temperature, the gas supply unit is turned on to introduce air into the cracking furnace 600 for coking operation.

[0170] In step S60, the coking operation is performed: the pyrolysis and product separation device is restarted, the main gas supply pipe 900 and its branch gas supply pipes are closed, and the pyrolysis heating furnace 600 is started to heat the first convection section furnace tube 601, the first radiation section furnace tube 602, the second convection section furnace tube 603, the second radiation section furnace tube 604, the third convection section furnace tube 605, and the third radiation section furnace tube 606; the first quench cooler 802 and the second quench cooler 803 on the first pyrolysis gas pipe 801 are started for cooling; the cooling tank 800, the cooling coil 805 inside the cooling tank 800, and the cooling pipe 804 at the cooling tank outlet are started for cooling; the cryogenic tank inlet cooling pipe 810, the cryogenic tank 808, the cryogenic coil 815 inside the cryogenic tank 808, and the cryogenic tank outlet cooling pipe 811 are started for cooling. The controlled temperatures of the first convection section furnace tube 601, the second convection section furnace tube 603, and the third convection section furnace tube 605 are all 500℃~550℃, and the controlled temperatures of the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 are all 710℃~1000℃. The controlled temperatures of the first quench cooler 802, the second quench cooler 803, the cooling tank 800, the cooling coil 805, the cooling tank outlet cooling pipe 804, the cryogenic tank inlet cooling pipe 810, and the cryogenic tank outlet cooling pipe 811 are all 5℃~30℃, and the controlled temperatures of the cryogenic tank 808 and the cryogenic coil 815 are both 0℃~5℃.

[0171] Furthermore, the main gas supply pipe 900 and the corresponding branch gas supply pipes are opened to introduce air, the temperature of each radiant section furnace tube in the pyrolysis and product separation device is adjusted, the feed rate of the water pump on the corresponding water supply pipe in the pyrolysis and product separation device is set, and the coking operation is carried out.

[0172] After coking is completed, shut off the main gas supply pipe 900 and the corresponding branch gas supply pipes, and stop heating of the pyrolysis and product separation device. When the temperatures of the first radiant section furnace tube 602, the second radiant section furnace tube 604, and the third radiant section furnace tube 606 are all not higher than 300℃, stop feeding into the second water tank 700, the third water tank 705, and the fourth water tank 710 in the pyrolysis and product separation device. After emptying the cooling tank 800 and the cryogenic tank 808, shut off the cooling tank discharge pipe 806 and the cryogenic tank discharge pipe 816.

[0173] The following provides experimental results using the crude oil vapor cracking evaluation apparatus and method described in this invention.

[0174] The results of the simulated distillation analysis of crude oil are shown in Table 1.

[0175] Table 1 Results of Crude Oil Simulation Distillation Analysis

[0176]

[0177]

[0178] The operating conditions and flash calibration results of the crude oil processing unit are shown in Table 2. The top fraction of the second flash tank is the second gas phase fraction mentioned above, the bottom fraction of the second flash tank is the second liquid phase fraction mentioned above, and the buffer tank fraction is the third liquid phase fraction mentioned above.

[0179] Table 2 Operating conditions and flash calibration results of crude oil processing unit

[0180]

[0181]

[0182] The analytical results of the fractions collected by different flash evaporation calibrations are shown in Table 3.

[0183] Table 3. Analytical results of fractions collected from different flash evaporation calibrations.

[0184]

[0185] The results of different pyrolysis conditions and pyrolysis product yields are shown in Table 4.

[0186] Table 4. Results of different pyrolysis conditions and pyrolysis product yields

[0187]

[0188]

[0189] Among them, Comparative Examples 1, 2, and 3 are the process conditions and cracking product yields used in the direct steam cracking of crude oil in Table 1.

[0190] As can be seen from Table 4, this invention achieves increased production of ethylene, propylene and butadiene through the fractional steam cracking process of crude oil. Its evaluation results have high reference value for industrial cracking furnaces and can demonstrate the optimal cracking conditions and cracking performance of crude oil feedstocks.

[0191] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A crude oil steam cracking method, characterized in that, include: After the crude oil is mixed with steam, it enters the first flash tank (300) for the first flash separation to obtain the first gas phase fraction and the first liquid phase fraction; The first vapor fraction is passed into the second flash tank (400) for second flash separation to obtain the second vapor fraction and the second liquid fraction. At the same time, the first liquid fraction is passed into the buffer tank (500) to obtain the third liquid fraction. The second gas phase fraction, the second liquid phase fraction, and the third liquid phase fraction are respectively fed into the convection section of the pyrolysis heating furnace (600) for heating, and then respectively enter the radiation section of the pyrolysis heating furnace (600) for pyrolysis; The pyrolysis gas generated in the pyrolysis heating furnace (600) by the second gas phase fraction, the second liquid phase fraction and the third liquid phase fraction is cooled.

2. The crude oil steam cracking method according to claim 1, characterized in that, The convection section inside the pyrolysis heating furnace (600) is connected to a water supply unit; Within the convection section of the pyrolysis heating furnace (600), the second vapor fraction, the second liquid fraction, and the third liquid fraction are mixed with water and / or steam supplied by the water supply unit, respectively.

3. The crude oil steam cracking method according to claim 1, characterized in that, A gas supply unit is connected between the convection section and the radiation section of the pyrolysis heating furnace (600); After the crude oil is cracked, the air in the gas supply unit enters the radiation section of the cracking furnace (600) for coking.

4. A crude oil steam cracking evaluation system, characterized in that, Including connected crude oil processing units and cracking and product separation units; The crude oil processing unit includes: The first flash unit has an inlet connected to a raw material supply unit and a steam supply unit. The second flash unit has its inlet connected to the gas phase outlet of the first flash unit; A buffer unit, the inlet of which is connected to the liquid phase outlet of the first flash evaporation unit; The pyrolysis and product separation device includes: The pyrolysis heating furnace (600) is provided with three sets of parallel convection sections and radiation sections. Each set of convection sections and radiation sections are connected. The three sets of convection sections are respectively connected to the gas phase outlet of the second flash evaporation unit, the liquid phase outlet of the second flash evaporation unit and the liquid phase outlet of the buffer unit. The three sets of liquid supply units are respectively connected to the inlets of the three sets of convection sections; The cooling unit is connected to the outlet of the three sets of radiation sections.

5. The crude oil steam cracking evaluation system according to claim 4, characterized in that, The raw material supply unit includes: A raw material tank (100) is used to store crude oil. The raw material tank (100) is equipped with a stirrer (101) and a raw material tank heater (102). The first measuring device (103) is placed on the first measuring device (103) via the raw material tank support (104); A raw material supply pipe (105) is connected between the raw material tank (100) and the first flash unit. A raw material pump (108) and a raw material preheater (109) are provided on the raw material supply pipe (105).

6. The crude oil steam cracking evaluation system according to claim 4, characterized in that, The steam supply unit includes: The first water tank (200) is used to store water; The second measuring device (201) is placed on the first water tank (200); A steam supply pipe (202) is connected between the first water tank (200) and the first flash evaporation unit. The steam supply pipe (202) is equipped with a first water pump (203) and a vaporizer (204).

7. The crude oil steam cracking evaluation system according to claim 4, characterized in that, The first flash unit includes: A first flash tank (300) has an inlet, a gas phase outlet and a liquid phase outlet, and the inlet of the first flash tank (300) is connected to the raw material supply unit and the steam supply unit. The first flash heater (301) is located on the pipe connected to the inlet of the first flash tank (300).

8. The crude oil steam cracking evaluation system according to claim 7, characterized in that, The second flash unit includes: The second flash tank (400) has an inlet, a gas phase outlet and a liquid phase outlet. The inlet of the second flash tank (400) is connected to the gas phase outlet of the first flash tank (300) through a first gas phase distillation pipe (302). The gas phase outlet of the second flash tank (400) is connected to a second gas phase distillation pipe (401). The liquid phase outlet of the second flash tank (400) is connected to a second liquid phase distillation pipe (408). The second flash heater (303) is installed on the first vapor phase distillation tube (302).

9. The crude oil steam cracking evaluation system according to claim 8, characterized in that, The buffer unit includes: A buffer tank (500) has a first inlet and a liquid phase outlet. The first inlet of the buffer tank (500) is connected to the liquid phase outlet of the first flash tank (300) through a first liquid phase distillation pipe (305). The liquid phase outlet of the buffer tank (500) is connected to a third liquid phase distillation pipe (501).

10. The crude oil steam cracking evaluation system according to claim 9, characterized in that, The buffer tank (500) also has a second inlet, which is connected to the liquid phase outlet of the second flash tank (400) via a fourth liquid phase distillation pipe (415).

11. The crude oil steam cracking evaluation system according to claim 10, characterized in that, The first liquid phase distillation pipe (305) is connected to a first liquid phase distillation discharge pipe (306); and / or The second vapor fraction pipe (401) is connected to a second vapor fraction discharge pipe (402); and / or A second liquid phase fraction discharge pipe (409) is connected to the second liquid phase fraction pipe (408) or the fourth liquid phase fraction pipe (415); and / or The third liquid phase distillation pipe (501) is connected to the third liquid phase distillation discharge pipe (502).

12. The crude oil steam cracking evaluation system according to claim 9, characterized in that, The first flash evaporator (300) is provided with a first heating coil (310), and a first heating wire (311) is sleeved on the outer periphery of the first flash evaporator (300); and / or The second flash evaporator (400) is provided with a second heating coil (416), and a second heating wire (417) is sleeved on the outer periphery of the second flash evaporator (400); and / or The buffer tank (500) is provided with a third heating coil (507), and the buffer tank (500) is provided with a third heating wire (508) on its outer periphery.

13. The crude oil steam cracking evaluation system according to claim 9, characterized in that, The pyrolysis heating furnace (600) includes: The first convection section furnace tube (601) and the first radiation section furnace tube (602) are connected, and the first convection section furnace tube (601) is connected to the second vapor phase distillation tube (401). The second convection section furnace tube (603) and the second radiation section furnace tube (604) are connected, and the second convection section furnace tube (603) is connected to the second liquid phase distillation tube (408); The third convection section furnace tube (605) and the third radiation section furnace tube (606) are connected, and the third convection section furnace tube (605) is connected to the third liquid phase distillation tube (501).

14. The crude oil steam cracking evaluation system according to claim 13, characterized in that, The three sets of liquid supply units include: The second water tank (700) is placed on the third meter (701) and is connected to the first convection section furnace tube (601) through the first water supply pipe (702). The third water tank (705) is placed on the fourth meter (706) and is connected to the second convection section furnace tube (603) through the second water supply pipe (707). The fourth water tank (710) is placed on the fifth meter (711) and is connected to the third convection section furnace tube (605) through the third water supply pipe (712).

15. The crude oil steam cracking evaluation system according to claim 13, characterized in that, The cooling unit includes: Cooling tank (800), the inlet of which is connected to the first radiant section furnace tube (602), the second radiant section furnace tube (604) and the third radiant section furnace tube (606) via a first pyrolysis gas pipe (801); A cryogenic tank (808) is provided, the inlet of which is connected to the outlet of the cooling tank (800), and the outlet of the cryogenic tank (808) is connected to a second pyrolysis gas pipe (809).

16. The crude oil steam cracking evaluation system according to claim 15, characterized in that, Along the flow direction of the pyrolysis gas in the first pyrolysis gas pipe (801), a first quench cooler (802) and a second quench cooler (803) are sequentially provided on the first pyrolysis gas pipe (801); and / or The pipes connected to the outlet of the cooling tank (800), the pipes connected to the inlet of the cryogenic tank (808), and the pipes connected to the outlet of the cryogenic tank (808) are all fitted with a section of cooling pipe.

17. The crude oil steam cracking evaluation system according to claim 15, characterized in that, The cooling tank (800) is provided with a cooling coil (805); and / or, the cryogenic tank (808) is provided with a cryogenic coil (815).

18. The crude oil steam cracking evaluation system according to claim 15, characterized in that, The bottom of the cooling tank (800) is connected to a cooling tank discharge pipe (806); and / or, the bottom of the cryogenic tank (808) is connected to a cryogenic tank discharge pipe (816).

19. The crude oil steam cracking evaluation system according to claim 15, characterized in that, Along the flow direction of the pyrolysis gas in the second pyrolysis gas pipe (809), a pressure regulating valve (812), a gas buffer bottle (813) and a flow meter are sequentially provided on the second pyrolysis gas pipe (809).

20. The crude oil steam cracking evaluation system according to claim 13, characterized in that, The pyrolysis and product separation device includes a gas supply unit, which includes: The first gas supply pipe (903) is connected to the pipe where the first convection section furnace tube (601) and the second gas phase distillation pipe (401) meet; The second gas supply pipe (904) is connected to the pipe where the second convection section furnace tube (603) and the second liquid phase distillation pipe (408) meet; The third gas supply pipe (905) is connected to the pipe where the third convection section furnace tube (605) and the third liquid phase distillation pipe (501) meet.

21. A method for evaluating crude oil steam cracking, characterized in that, The crude oil vapor cracking evaluation system according to any one of claims 4 to 20 is used, and the crude oil vapor cracking evaluation method includes: Start the pyrolysis and product separation device. When the pyrolysis heating furnace (600) is heated to the predetermined temperature and the cooling unit is cooled to the predetermined temperature, open the liquid supply unit to supply water into the pyrolysis heating furnace (600). Start the crude oil processing unit to raise the temperature of the first flash unit, the second flash unit and the buffer unit to the predetermined temperature; The raw material supply unit and steam supply unit were started to supply materials to the first flash unit for preliminary experiments; Conduct formal tests and record the supply and output of each raw material before and after the formal tests. After the cracking and product separation unit and the crude oil processing unit have cooled down, shut them down.

22. The crude oil steam cracking evaluation method according to claim 21, characterized in that, The pyrolysis and product separation device also includes an air supply unit for introducing air into the pyrolysis heating furnace (600); The crude oil vapor cracking evaluation method also includes: After the cracking and product separation unit and the crude oil processing unit are shut down, the cracking and product separation unit is restarted. When the cracking furnace (600) is heated to the predetermined temperature, the gas supply unit is turned on to introduce air into the cracking furnace (600) for coking operation.

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