Quenching system and method for preliminary fractionation of cracked gas

Abstract

The invention relates to the field of petrochemical equipment, in particular to a quenching system and method for preliminary fractionation of pyrolysis gas. The quenching system comprises a quenching steam stripping unit which comprises a quenching oil tower, a quenching water tower and a light hydrocarbon steam stripping tower which are sequentially connected in series; the product separation part comprises a separation unit and an octane removal tower, and a heavy hydrocarbon component discharge port of the separation unit and a discharge port of the light hydrocarbon stripping tower are both communicated with a feed port of the octane removal tower; the reflux unit comprises a first reflux pipeline, a second reflux pipeline and a third reflux pipeline, and the first reflux pipeline is communicated with the tower bottom of the quenching water tower and the tower top of the quenching oil tower; a second reflux pipeline is communicated with the tower bottom of the light hydrocarbon stripping tower and the tower top of the quenching oil tower; and a third reflux pipeline is communicated with the tower bottom of the octane removal tower and the tower top of the quenching oil tower. According to the quenching system, accurate control over the content of the light components in the quenching oil tower is achieved through three core mechanisms of backflow enhanced separation, step-by-step light component transfer and low light component backflow supplement.

Description

Technical Field

[0001] This application relates to the field of petrochemical equipment, and in particular to a quenching system and method for the preliminary fractionation of cracked gas. Background Technology

[0002] The quench system is a key unit for the stable operation of an ethylene plant, mainly composed of a quench oil tower, a quench water tower, and a process water recovery system. The quench system is responsible for the initial fractionation of the cracked gas, primarily achieving the goals of pre-fractionation of oil products, recovery of lower-grade heat, and recycling of process water. The quench oil tower in the quench system needs to be designed to maximize heat utilization while effectively separating gasoline and fuel oil, minimizing the impact of fuel oil on downstream systems, based on the characteristics of the cracked gas components. However, cracked gas suffers from complex composition, demanding operating conditions, and numerous bottlenecks during long-term operation; these are all critical factors for the operation of the quench system. Current solutions to these challenges primarily involve a combination of quench oil and quench water towers to achieve initial fractionation of the cracked gas. In this combination, the quench oil tower mainly removes heavy components such as light diesel oil and fuel oil, while the quench water tower is used for further fractionation, with the resulting gasoline-like substances used as the first reflux material for the quench oil tower. Meanwhile, the pyrolysis gas from the top of the quench tower is pressurized and condensed by a compressor. The condensed hydrocarbons then enter the light hydrocarbon stripping tower, where light components are stripped from the top. A portion of the heavy components from the bottom of the light hydrocarbon stripping tower serves as the second reflux material for the quench oil tower. The pyrolysis gas, after being pressurized by the compressor, enters the downstream system for separation. The resulting heavy components with C5 or higher carbon content can be used as pyrolysis gasoline products.

[0003] However, with the trend towards lighter and higher-quality feedstocks in pyrolysis, many ethylene plants now primarily use light feedstocks such as ethane, propane, C4, and light naphtha. This results in a lighter composition of the pyrolysis gas compared to previous quench systems, with lower gasoline and fuel oil content, making it easier for these components to be carried downstream. Furthermore, the gasoline-like components in the pyrolysis gas are mainly C6 to C9 organic components, while the content of C8 and C9 organic components is reduced. This distribution characteristic means that the amount of gasoline-like material in the quench tower bottom is insufficient to meet the reflux requirements of the quench oil tower. This leads to a higher concentration of heavy components in the pyrolysis gas at the top of the quench oil tower, increasing the risk of heavy components entering the downstream system and ultimately resulting in substandard gasoline products. In addition, the bottom components of the light hydrocarbon stripping tower are also lighter. When used as a secondary reflux material, the control effect of the quench oil tower top temperature is not significant, leading to a large amount of light components circulating between the quench and compression zones, increasing the operating power consumption of both zones. Summary of the Invention

[0004] This application provides a quenching system and method for the preliminary fractionation of cracked gas to solve the following technical problem: how to improve the controllability of the light component content in the quenching oil tower.

[0005] In a first aspect, embodiments of this application provide a quenching system for the preliminary fractionation of cracked gas, the quenching system comprising: The quench stripping unit includes a quench oil tower, a quench water tower, and a light hydrocarbon stripping tower. The top of the quench oil tower is connected to the bottom of the quench water tower, and the top of the quench water tower is connected to the light hydrocarbon stripping tower. The product separation section includes a separation unit and a deoctane tower. The top outlet of the light hydrocarbon stripping tower is connected to the inlet of the separation unit. The outlet of the heavy hydrocarbon component of the separation unit and the outlet of the light hydrocarbon stripping tower are both connected to the inlet of the deoctane tower. The reflux unit includes a first reflux pipe, a second reflux pipe, and a third reflux pipe. The inlet of the first reflux pipe is connected to the bottom outlet of the quench water tower, and the outlet of the first reflux pipe is connected to the top inlet of the quench oil tower. The inlet of the second reflux pipe is connected to the bottom outlet of the light hydrocarbon stripping tower, and the outlet of the second reflux pipe is connected to the top inlet of the quench oil tower. The inlet of the third reflux pipe is connected to the bottom outlet of the deoctane tower, and the outlet of the third reflux pipe is connected to the top inlet of the quench oil tower.

[0006] Optionally, the quench oil tower includes, from top to bottom, a light fuel oil extraction section, a quench oil circulation section, and a flash evaporation section. The top outlet of the light fuel oil extraction section is connected to the bottom of the quench oil tower, the bottom outlet of the light fuel oil extraction section is used to discharge light fuel oil components, and the bottom outlet of the flash evaporation section is used to discharge heavy fuel oil components.

[0007] Optionally, the quench stripping unit further includes a light fuel oil stripping tower, the inlet of which is connected to the bottom outlet of the light fuel oil extraction section to extract light fuel oil components.

[0008] Optionally, the quenching system further includes: It includes at least two cooling compressor units, at least one of the cooling compressor units is located between the top outlet of the light hydrocarbon stripping tower and the inlet of the separation unit, and at least one of the cooling compressor units is located between the top outlet of the quench water tower and the inlet of the light hydrocarbon stripping tower.

[0009] Optionally, the cooling and compression unit includes a first cooling compressor unit, a second cooling compressor unit, a third cooling compressor unit, and a fourth cooling compressor unit. The inlet of the first cooling compressor unit is connected to the top outlet of the quench tower, the outlet of the first cooling compressor unit is connected to the inlet of the light hydrocarbon stripping tower, the inlet of the second cooling compressor unit is connected to the top outlet of the light hydrocarbon stripping tower, the outlet of the second cooling compressor unit is connected to the inlet of the third cooling compressor unit, the outlet of the third cooling compressor unit is connected to the inlet of the fourth cooling compressor unit, and the outlet of the fourth cooling compressor unit is connected to the inlet of the separation unit.

[0010] Secondly, embodiments of this application provide a quenching method for the preliminary fractionation of cracked gas, the quenching method being adapted to the quenching system described in the first aspect, the quenching method comprising: The pyrolysis gas is first quenched using quench oil to obtain the first pyrolysis gas. The first pyrolysis gas is subjected to a second rapid cooling using quench water to obtain a first reflux material and a second pyrolysis gas; wherein the first reflux material is reused in the first rapid cooling. The second cracked gas is sequentially compressed, condensed, and stripped of light hydrocarbons to obtain a third cracked gas, a second reflux material, and a first cracked gasoline; wherein the second reflux material is reused in the first quenching process. The third cracked gas is compressed and separated sequentially to obtain the second cracked gasoline; The first pyrolysis gasoline and the second pyrolysis gasoline are combined to obtain pyrolysis gasoline; The cracked gasoline is subjected to deoctane treatment to obtain C9-rich cracked gasoline and a third reflux material; wherein the third reflux material is reused in the first quench.

[0011] Optionally, the mass m1 of the first reflux material and the mass m2 of the second cracked gas satisfy: m1:m2=1:(5 to 2); and / or The mass m3 of the second reflux material and the mass m4 of the third pyrolysis gas satisfy: m3:m4 = 1:(80 to 50); and / or The mass m5 of the third reflux material and the mass m6 of the C9-rich cracked gasoline satisfy the following: m5:m6=1:(50 to 20).

[0012] Optionally, the temperature of the first rapid cooling is 100°C to 200°C; and / or The temperature of the second rapid cooling is 20°C to 90°C.

[0013] Optionally, the stripping temperature of the light hydrocarbons is from 30°C to 180°C; and / or The temperature for the deoctane treatment is from 40°C to 200°C.

[0014] Optionally, the pressure of the first quench is 0.1 MPa to 0.3 MPa.

[0015] Optionally, the pressure of the light hydrocarbon stripping is 0.1 MPa to 0.3 MPa; and / or The compression pressure is 1 MPa to 5 MPa; and / or The pressure of the deoctane treatment is from 0.05 MPa to 0.2 MPa.

[0016] Optionally, the step of using quenching oil to perform a first quench cooling on the pyrolysis gas to obtain a first pyrolysis gas includes the following steps: The cracked gas is first quenched using quench oil to obtain first cracked gas, heavy fuel oil components and light fuel oil components crude products. The crude light fuel oil component is subjected to fuel oil stripping to obtain the light fuel oil component.

[0017] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a quench system for the preliminary fractionation of cracked gas. This quench system rapidly cools the cracked gas in two stages: through a quench oil tower and a quench water tower. Then, a light hydrocarbon stripping tower extracts the lighter components of the cracked gas, achieving the separation of most of the materials in the cracked gas. A separation system and a deoctane tower further separate the C9 components from the C8 and C9 components in the stripping gas. Additionally, a reflux unit including a first reflux pipe, a second reflux pipe, and a third reflux pipe is used. The heavier fractions from the bottom of the quench water tower are returned to the reflux system via the first reflux pipe. The heavier fractions from the bottom of the light hydrocarbon stripping tower can be further recycled to the quench oil tower via the second reflux pipe. Finally, the heavier C8 and C9 fractions separated from the deoctane tower can be further recycled to the quench oil tower via the third reflux pipe. These heavier fractions recycled through the first, second, and third reflux pipes can increase the content of gasoline-like materials in the quench water tower, thereby controlling the content of light components at the top of the quench oil tower and achieving the optimal distribution of heat and materials between the quench oil tower and the quench water tower. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the logic structure of a quenching system for preliminary fractionation of cracked gas provided in this application embodiment; Figure 2 A schematic diagram of a quench system for preliminary fractionation of pyrolysis gas provided in this application embodiment; Figure 3 A schematic diagram of a rapid cooling method for preliminary fractionation of pyrolysis gas provided in this application embodiment; Figure 4 A detailed flow diagram of a quenching method for preliminary fractionation of pyrolysis gas provided in this application embodiment; Among them, 1-quench oil tower, 101-light fuel oil extraction section, 102-quench oil circulation section, 103-flash section, 2-quench water tower, 3-light hydrocarbon stripping tower, 4-separation unit, 5-deoctane tower, 6-first reflux pipeline, 7-second reflux pipeline, 8-third reflux pipeline, 9-cooling compression unit, 901-first cooling compressor unit, 902-second cooling compressor unit, 903-third cooling compressor unit, 904-fourth cooling compressor unit, 10-light fuel oil stripping tower. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The range descriptions used in this application, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "comprising" and others used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships involved in this document, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained by purchasing from the market or by existing methods.

[0023] Figure 1 An exemplary schematic diagram of the logic structure of a quenching system for preliminary fractionation of cracked gas provided in an embodiment of this application is shown. Figure 2 An exemplary schematic diagram of a quench system for preliminary fractionation of cracked gas provided in an embodiment of this application is shown; like Figure 1 and Figure 2 As shown in the embodiment of this application, a quenching system for the preliminary fractionation of cracked gas is provided, the quenching system comprising: The quench stripping unit includes a quench oil tower 1, a quench water tower 2, and a light hydrocarbon stripping tower 3. The top of the quench oil tower 1 is connected to the bottom of the quench water tower 2, and the top of the quench water tower 2 is connected to the light hydrocarbon stripping tower 3. The product separation section includes a separation unit 4 and a deoctane tower 5. The top outlet of the light hydrocarbon stripping tower 3 is connected to the inlet of the separation unit 4. The outlet of the heavy hydrocarbon component of the separation unit 4 and the outlet of the light hydrocarbon stripping tower 3 are both connected to the inlet of the deoctane tower 5. The reflux unit includes a first reflux pipe 6, a second reflux pipe 7, and a third reflux pipe 8. The inlet of the first reflux pipe 6 is connected to the bottom outlet of the quench water tower 2, and the outlet of the first reflux pipe 6 is connected to the top inlet of the quench oil tower 1. The inlet of the second reflux pipe 7 is connected to the bottom outlet of the light hydrocarbon stripping tower 3, and the outlet of the second reflux pipe 7 is connected to the top inlet of the quench oil tower 1. The inlet of the third reflux pipe 8 is connected to the bottom outlet of the deoctane tower 5, and the outlet of the third reflux pipe 8 is connected to the top inlet of the quench oil tower 1.

[0024] It should be noted that the components of this cracked gas mainly include hydrogen, methane, ethylene, propylene, butene, butadiene, ethane, propane, butane, C5, C6, benzene, toluene, ethylbenzene, styrene, methylbenzene, indene, naphthalene, methylnaphthalene, C10 alkanes, and hydrocarbons with more than C11 hydrocarbons.

[0025] It should be noted that the bottom of the quench tower 2 can use an oil-water separation structure to efficiently separate gasoline-like materials and water. This oil-water separation structure can prevent the water in the gasoline-like materials from causing the quench tower 1 to boil over, thereby improving the stability of the overall quench system.

[0026] It should be noted that the separation unit 4 can be processed using a depentanizer to remove C5 light components from the cracked gas after processing by the light hydrocarbon stripper 3.

[0027] This application provides a quench system for the preliminary fractionation of cracked gas. This quench system achieves precise control of the light component content within the quench tower 1 through three core mechanisms: enhanced separation via reflux, stepwise transfer of light components, and reflux replenishment of low-light components. The specific mechanisms are as follows: I. Core Concepts: Definition and Control Objectives of Light Components Light components typically refer to hydrocarbons with lower boiling points in the cracked gas (such as C1 to C5 alkanes and alkenes), which are easily volatile and difficult to retain stably in the heavy distillation components. The control objective is to avoid excessive accumulation of light components in quench oil tower 1 and quench water tower 2 (otherwise it will reduce tower efficiency and increase energy consumption), while transferring them to subsequent units for recovery through step-by-step separation.

[0028] II. Light Component Control Mechanism of Quenching Oil Tower 1 Quenching oil tower 1 is the core equipment for the initial cooling and separation of cracked gas, mainly separating heavy fractions (such as quench oil). Lighter components need to be discharged from the top of the tower and enter quench water tower 2. The system enhances the separation of light components through three-stage reflux synergy, as follows: 1. First reflux: The bottom material of quench tower 2 is refluxed to reduce the retention of light components. Process: The bottom of the quench water tower 2 (containing a small amount of incompletely separated light components and heavier fractions) is returned to the top of the quench oil tower 1 through the first reflux pipe 6.

[0029] Function: The light component content of the bottom material of quench water tower 2 is already lower than that of the top material of quench oil tower 1. After reflux, it can replenish the "cooling-separation medium" at the top of quench oil tower 1. The low temperature environment at the top of the tower promotes the volatilization of the residual light components to the top of the tower, preventing them from being discharged from the bottom of the tower with the heavy fraction, thus avoiding the accumulation of light components.

[0030] 2. Second reflux: The bottom material of the light hydrocarbon stripping tower 3 is refluxed to enhance the upward migration of light components. Process: The bottom product of light hydrocarbon stripping tower 3 (heavier fraction with extremely low light component content after stripping) is returned to the top of quench oil tower 1 through the second reflux pipe 7.

[0031] Function: The core function of the light hydrocarbon stripping tower 3 is to separate light components from the top of the tower, while the bottom material contains almost no light components. This reflux can significantly increase the reflux ratio (reflux liquid rate / feed rate) at the top of the quench oil tower 1, enhancing the "gas-liquid mass transfer" within the tower: light components, due to their lower boiling point, are more likely to rise to the top of the tower with the gas phase, while the heavy components in the reflux liquid inhibit the diffusion of light components to the bottom of the tower, thereby reducing the retention of light components in the quench oil tower 1.

[0032] 3. Third reflux: The bottom material of deoctane tower 5 is refluxed to cut off the accumulation of light components in circulation. Process: The bottom product of the deoctane tower 5 (heavy fraction after separation of light components, such as hydrocarbon products with C9 or higher) is returned to the top of the quench oil tower 1 through the third reflux pipe 8.

[0033] Function: The deoctane tower 5 is one of the terminal units for deep separation of light components. The content of light components in the bottom material of the tower is extremely low (the light components have been separated and recovered from the top or side stream). This reflux further replenishes the heavy reflux medium at the top of the quench oil tower 1, avoiding the accumulation of trace amounts of light components brought in by the previous reflux. At the same time, the dilution effect of the heavy medium reduces the partial pressure of light components in the gas phase at the top of the tower, promoting their transfer to the quench water tower 2.

[0034] III. Light Component Control Mechanism of Quenching Tower 2 Quenching tower 2 receives the light components from the top of quenching oil tower 1. After further cooling and separation, the light components need to be directionally transferred to light hydrocarbon stripping tower 3 to avoid their own accumulation. Its core mechanism is "unidirectional output of light components + reflux purification": 1. Directed transfer of light components to light hydrocarbon stripping tower 3 The feed to the quench tower 2 is the light component (containing more C3 to C6 hydrocarbons) from the top of the quench oil tower 1. Through internal cooling (e.g., quench water spray), some of the heavier components condense to the bottom of the quench tower 2, while the lighter components are still discharged from the top of the tower in gaseous form. After compression and cooling, they enter the light hydrocarbon stripping tower 3.

[0035] The light hydrocarbon stripping tower 3 completely separates the light components at the top of the tower through heating or stripping (sent to the separation unit 4 for recovery), reducing the "input-accumulation" closed loop of light components in the quench water tower 2 from the source.

[0036] 2. Bottom reflux purification reduces light component residue. The bottom material of quench tower 2 (containing a small amount of unseparated light components and heavier fractions) is returned to quench oil tower 1 through the first reflux pipe 6, instead of circulating within quench tower 2. This design allows the incompletely separated light components in quench tower 2 to be sent back upstream for re-separation, preventing their accumulation at the bottom and thus increasing the light component content.

[0037] In summary, the quench system for preliminary fractionation of cracked gas provided in this application embodiment achieves control over the light component content of quench oil tower 1 through a synergistic design of "reflux to enhance separation efficiency + stepwise directional transfer of light components + low light component reflux to prevent accumulation". (1) For quench oil tower 1: improve the separation efficiency at the top of the tower by three-stage low light component reflux, and promote the transfer of light components to quench water tower 2; (2) For quench tower 2: the light components at the top of the tower are unidirectionally output to the light hydrocarbon stripping tower 3, and combined with the bottom reflux purification, the light components are prevented from being retained. Finally, the light components of the cracked gas are efficiently transferred to the subsequent separation unit 4 for recovery, ensuring the stable operation of the quench system.

[0038] In some optional embodiments, the quench oil tower 1 includes, from top to bottom, a light fuel oil extraction section 101, a quench oil circulation section 102, and a flash section 103. The top outlet of the light fuel oil extraction section 101 is connected to the bottom of the quench water tower 2, the bottom outlet of the light fuel oil extraction section 101 is used to discharge light fuel oil components, and the bottom outlet of the flash section 103 is used to discharge heavy fuel oil components.

[0039] In these embodiments, the quench oil tower 1 is divided into a light fuel oil extraction section 101, a quench oil circulation section 102, and a flash section 103. The light fuel oil extraction section 101 mixes the reflux materials introduced from various reflux pipelines with the cracked gas to control the amount of light fuel oil extracted from the quench oil tower 1 and entering the subsequent fuel oil stripping tower 10. In addition, the quench oil circulation section 102 can remove heat from the quench oil tower 1 and improve the cooling effect of the quench oil tower 1. The flash section 103 can separate some heavy fuel oil components from the cracked gas and form some light fuel oil components, which can be purified by the subsequent fuel oil stripping tower 10 to obtain pure light fuel oil components. The distribution structure of the quench oil tower 1 can be combined with the reflux unit to allow substances with more than ten carbon atoms, such as naphthalene and methylnaphthalene, to circulate into the top of the quench oil tower 1, so as to prevent these materials from entering the downstream system. The output of crude light fuel oil is controlled through these three parts of the structure, so as to control the output of subsequent light fuel oil components and prevent light fuel oil components from entering the downstream.

[0040] In some optional embodiments, the quench stripping unit further includes a light fuel oil stripping tower 10, the inlet of which is connected to the bottom outlet of the light fuel oil extraction section 101 to extract light fuel oil components.

[0041] In these embodiments, a fuel oil stripping tower 10 is introduced into the quench stripping unit. The heavy hydrocarbon components of light fuel oil can be obtained through the fuel oil stripping tower 10, preventing the heavy hydrocarbon components of light fuel oil from entering the downstream and improving the controllability of light components in the quench oil tower 1.

[0042] In some alternative implementations, the quenching system further includes: The cooling and compression unit 9 includes at least two cooling compressor units, at least one of which is located between the top outlet of the light hydrocarbon stripping tower 3 and the inlet of the separation unit 4, and at least one of which is located between the top outlet of the quench tower 2 and the inlet of the light hydrocarbon stripping tower 3.

[0043] In these embodiments, at least four cooling compressor units are introduced into the quench system. The compression and condensation of the cooling compressor units can serve as a supplementary means to prevent a large amount of light components from circulating between the quench zone and the compression zone. This avoids the light components increasing the operating energy consumption between the quench zone and the compression zone, and also prevents the heavy hydrocarbon components of the light fuel oil from being carried into the downstream deoctane tower 5, thereby improving the overall efficiency of the quench system.

[0044] It should be noted that the cooling compressor unit may include a compressor and a cooler, with the cooler located downstream of the compressor to recover the heat generated by the compressor.

[0045] In some optional embodiments, the cooling compression unit 9 includes a first cooling compressor unit 901, a second cooling compressor unit 902, a third cooling compressor unit 903, and a fourth cooling compressor unit 904. The inlet of the first cooling compressor unit 901 is connected to the top outlet of the quench tower 2, the outlet of the first cooling compressor unit 901 is connected to the inlet of the light hydrocarbon stripping tower 3, the inlet of the second cooling compressor unit 902 is connected to the top outlet of the light hydrocarbon stripping tower 3, the outlet of the second quench compressor unit is connected to the inlet of the third cooling compressor unit 903, the outlet of the third cooling compressor unit 903 is connected to the inlet of the fourth cooling compressor unit 904, and the outlet of the fourth cooling compressor unit 904 is connected to the inlet of the separation unit 4.

[0046] In these embodiments, a first cooling compressor unit 901, a second cooling compressor unit 902, a third cooling compressor unit 903, and a fourth cooling compressor unit 904 are introduced into the cooling compression unit 9. The first cooling compressor unit 901 can compress the top material of the quench tower 2, which is beneficial to the stripping process of the light hydrocarbon stripping tower 3 and recovers a large amount of gasoline-like materials. The second cooling compressor unit 902, the third cooling compressor unit 903, and the fourth cooling compressor unit 904 can further compress the top material of the light hydrocarbon stripping tower 3, which is beneficial to the subsequent separation of gasoline-like materials by the separation unit 4 and the subsequent processing by the deoctane tower 5.

[0047] It should be noted that a separation tank can be installed at the feed inlet of the third cooling compressor unit 903 and the fourth cooling unit to separate hydrocarbons and water, preventing hydrocarbons from re-entering the light hydrocarbon stripping tower 3. This allows the bottom of the light hydrocarbon stripping tower 3 to obtain heavier light fuel oil, thereby recovering gasoline-like materials and preventing these materials from entering the downstream separation unit 4, which would increase the energy consumption of the separation unit 4 and improve resource utilization.

[0048] Figure 3 An exemplary schematic diagram of a rapid cooling method for preliminary fractionation of cracked gas provided in an embodiment of this application is shown. Based on a general inventive concept, such as Figure 3 As shown in the embodiment of this application, a quenching method for the preliminary fractionation of cracked gas is provided. The quenching method is adapted to the quenching system and includes: S1. The pyrolysis gas is first quenched using quench oil to obtain the first pyrolysis gas; S2. The first pyrolysis gas is subjected to a second rapid cooling using quench water to obtain a first reflux material and a second pyrolysis gas; wherein the first reflux material is reused in the first rapid cooling. S3. The second cracked gas is sequentially compressed, condensed, and stripped of light hydrocarbons to obtain a third cracked gas, a second reflux material, and a first cracked gasoline; wherein the second reflux material is reused in the first quenching process; S4. The third cracked gas is compressed and separated sequentially to obtain the second cracked gasoline; S5. Combine the first pyrolyzed gasoline and the second pyrolyzed gasoline to obtain pyrolyzed gasoline; S6. The cracked gasoline is subjected to deoctane treatment to obtain C9-rich cracked gasoline and a third reflux material; wherein the third reflux material is reused in the first quench.

[0049] The quenching method is based on the quenching system described above. The specific structure of the quenching system can be referred to in the above embodiments. Since the quenching method adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0050] It should be noted that the second cracked gasoline mainly consists of heavy components with C5 or higher. This second cracked gasoline can be combined with the first cracked gasoline obtained through light hydrocarbon stripping to form cracked gasoline. After deoctane treatment, hydrocarbons rich in C8 and C9 can be extracted from the side stream of this cracked gasoline. These hydrocarbons can be used as the third reflux feedstock in quench tower 1, increasing the content of heavy components in the reflux components of quench tower 1 during the first quenching stage. This enhances the reflux effect of the quenching system, thereby controlling the entry of C10 or higher components such as naphthalene and methylnaphthalene from the cracked gas into the downstream system, achieving controllability of the light components within quench tower 1.

[0051] In some optional embodiments, the mass m1 of the first reflux material and the mass m2 of the second cracked gas satisfy: m1:m2 = 1:(5 to 2); and / or The mass m3 of the second reflux material and the mass m4 of the third pyrolysis gas satisfy: m3:m4 = 1:(80 to 50); and / or The mass m5 of the third reflux material and the mass m6 of the C9-rich cracked gasoline satisfy the following: m5:m6=1:(50 to 20).

[0052] In these embodiments, the first reflux material and the second cracked gas, with a mass ratio of 1:(5 to 2), can reuse the heavier light fuel oil components obtained from the first quenching process through reflux, thereby preventing a large amount of light fuel oil from entering between the quenching zone and the compression zone, reducing the operating power consumption of the quenching zone and the compression zone, and thus achieving controllability of the light components within the quenching tower 1. Additionally, the second reflux material and the third cracked gas, with a mass ratio of 1:(80 to 50), can reuse the heavier light fuel oil components obtained from the second quenching process through reflux, thereby preventing a large amount of light fuel oil from entering between the quenching zone and the compression zone, and reducing the operating power consumption of the quenching zone and the compression zone. Furthermore, the third reflux material and the C9-rich cracked gasoline, with a mass ratio of 1:(50 to 20), can reuse the C8 and C9 light fuel oils from the deoctane treatment through reflux, thereby preventing a large amount of light fuel oil from entering between the quenching zone and the compression zone, and reducing the operating power consumption of the quenching zone and the compression zone.

[0053] The mass m2 of the second pyrolysis gas can be 5, 4, 3 or 2.

[0054] The mass m4 of the third pyrolysis gas can be 80, 75, 70, 65, 60, 55 or 50.

[0055] The mass m6 of the C9-rich cracked gasoline can be 50, 45, 40, 35, 30, 25 or 20.

[0056] In some alternative embodiments, the temperature of the first rapid cooling is 100°C to 200°C; and / or The temperature of the second rapid cooling is 20°C to 90°C.

[0057] In these embodiments, the first quenching at a temperature of 100°C to 200°C separates the heavy fuel oil from the fuel oil in the cracked gas, thereby preventing substances with more than ten C atoms from entering the downstream system and reducing the fuel oil content in the downstream system. Additionally, the second quenching at a temperature of 20°C to 90°C separates the heavy fuel oil from the water through oil-water separation, ensuring the purity of the first reflux material in the quenching tower 2 and preventing violent boiling in the quenching oil tower 1.

[0058] The temperature of the first rapid cooling can be 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃.

[0059] The temperature of the second rapid cooling can be 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃ or 90℃.

[0060] In some alternative embodiments, the temperature for stripping the light hydrocarbons is from 30°C to 180°C; and / or The temperature for the deoctane treatment is from 40°C to 200°C.

[0061] In these embodiments, light hydrocarbon stripping at temperatures ranging from 30°C to 180°C can separate the light fuel oil components entrained in the second cracked gas. This facilitates the subsequent merging of heavy components above C5 into cracked gasoline, preventing heavy components in the light fuel oil from entering the downstream deoctane treatment stage. This avoids a large amount of light fuel oil entering the quench zone and compression zone, reducing the operating power consumption of the quench zone and compression zone, and improving the controllability of light components within quench tower 1. Furthermore, deoctane treatment at temperatures ranging from 40°C to 200°C can separate the C8 and C9 components from the heavy components above C9 in the cracked gas. This improves the purity of the C8 and C9 components, facilitating the avoidance of these heavy components entering the downstream system through the third reflux material, and further improving the controllability of light components within quench tower 1.

[0062] The stripping temperature for light hydrocarbons can be 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, or 180℃.

[0063] The temperature for the deoctane treatment can be 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃.

[0064] In some alternative embodiments, the pressure of the first quench is 0.1 MPa to 0.3 MPa.

[0065] In these embodiments, the first rapid cooling at a pressure of 0.1 MPa to 0.3 MPa can separate the heavier light fuel oil from the heavy fuel oil in the cracked gas, thereby preventing substances with more than ten carbon atoms from entering the downstream system and reducing the content of heavy components in the light fuel oil in the downstream system.

[0066] In some alternative embodiments, the pressure of the light hydrocarbon stripping is 0.1 MPa to 0.3 MPa; and / or The compression pressure is 1 MPa to 5 MPa; and / or The pressure of the deoctane treatment is from 0.05 MPa to 0.2 MPa.

[0067] In these embodiments, light hydrocarbon stripping at a pressure of 0.1 MPa to 0.3 MPa can separate light fuel oil components from the second cracked gas, which is beneficial for the subsequent merging of heavy components above C5 to form cracked gasoline. This prevents heavy components in the light fuel oil from entering the downstream deoctane treatment stage, thus avoiding a large amount of light fuel oil entering between the quench and compression zones, reducing the operating power consumption of the quench and compression zones, and improving the controllability of light components in quench tower 1. In addition, compression at a pressure of 1 MPa to 5 MPa can fully compress the third cracked gas, which is beneficial for the subsequent separation system to separate heavy components above C5. Furthermore, deoctane treatment at a pressure of 0.05 MPa to 0.2 MPa can separate C8 and C9 components from heavy components above C9 in the cracked gas, which can improve the purity of C8 and C9 components. This is beneficial for preventing these heavy components from entering the downstream system through the third reflux material, and improves the controllability of light components in quench tower 1.

[0068] The pressure of the first rapid cooling can be 0.1 MPa, 0.15 MPa, 0.20 MPa, 0.25 MPa or 0.3 MPa.

[0069] The pressure for stripping light hydrocarbons can be 0.1 MPa, 0.15 MPa, 0.20 MPa, 0.25 MPa, or 0.3 MPa.

[0070] The compression pressure can be 1 MPa, 2 MPa, 3 MPa, 4 MPa or 5 MPa.

[0071] The deoctane treatment pressure is 0.05 MPa, 0.06 MPa, 0.07 MPa, 0.08 MPa, 0.09 MPa, 0.10 MPa, 0.15 MPa or 0.2 MPa.

[0072] It should be noted that the pressures of the first rapid cooling, the light hydrocarbon stripping, and the deoctane treatment are all absolute pressures.

[0073] Figure 4 A detailed flowchart illustrating a rapid cooling method for preliminary fractionation of cracked gas provided in an embodiment of this application is shown as an example. In some alternative implementations, such as Figure 4 As shown, the first quenching of the pyrolysis gas using quenching oil to obtain the first pyrolysis gas includes the following steps: S101. The cracked gas is subjected to a first rapid cooling using quenching oil to obtain a first cracked gas, a heavy fuel oil component, and a light fuel oil component crude product. S103. The crude light fuel oil component is subjected to fuel oil stripping to obtain the light fuel oil component.

[0074] In these embodiments, the fuel oil components obtained from the first cooling process are flash-evaporated to separate heavy fuel oil components and light fuel oil crude products. Then, by fuel oil stripping, the heavy fuel oil components mixed in with the light fuel oil crude product can be separated to obtain pure light fuel oil components.

[0075] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0076] Example 1 like Figure 1 and Figure 2 As shown, a quenching system for the preliminary fractionation of cracked gas is provided. The quenching system includes: The quench stripping unit includes a quench oil tower 1, a quench water tower 2, and a light hydrocarbon stripping tower 3. The top of the quench oil tower 1 is connected to the bottom of the quench water tower 2, and the top of the quench water tower 2 is connected to the light hydrocarbon stripping tower 3. The product separation section includes a separation unit 4 and a deoctane tower 5. The top outlet of the light hydrocarbon stripping tower 3 is connected to the inlet of the separation unit 4, and the outlet of the separation unit 4 and the outlet of the heavy hydrocarbon component of the light hydrocarbon stripping tower 3 are both connected to the inlet of the deoctane tower 5. The reflux unit includes a first reflux pipe 6, a second reflux pipe 7, and a third reflux pipe 8. The inlet of the first reflux pipe 6 is connected to the bottom outlet of the quench water tower 2, and the outlet of the first reflux pipe 6 is connected to the top inlet of the quench oil tower 1. The inlet of the second reflux pipe 7 is connected to the bottom outlet of the light hydrocarbon stripping tower 3, and the outlet of the second reflux pipe 7 is connected to the top inlet of the quench oil tower 1. The inlet of the third reflux pipe 8 is connected to the bottom outlet of the deoctane tower 5, and the outlet of the third reflux pipe 8 is connected to the top inlet of the quench oil tower 1.

[0077] The quench oil tower 1 consists of a light fuel oil extraction section 101, a quench oil circulation section 102, and a flash section 103 from top to bottom. The outlet of the light fuel oil extraction section 101 is connected to the bottom of the quench water tower 2. The bottom outlet of the light fuel oil extraction section 101 is used to discharge light fuel oil components, and the bottom outlet of the flash section 103 is used to discharge heavy fuel oil components.

[0078] The quench stripping unit also includes a fuel oil stripping tower 10, the inlet of which is connected to the bottom outlet of the light fuel oil extraction section 101 to extract light fuel oil components.

[0079] The quench system also includes: The cooling and compression unit 9 includes a first cooling compressor unit 901, a second cooling compressor unit 902, a third cooling compressor unit 903, and a fourth cooling compressor unit 904. The inlet of the first cooling compressor unit 901 is connected to the top outlet of the quench water tower 2, the outlet of the first cooling compressor unit 901 is connected to the inlet of the light hydrocarbon stripping tower 3, the inlet of the second cooling compressor unit 902 is connected to the top outlet of the light hydrocarbon stripping tower 3, the outlet of the second quench compressor is connected to the inlet of the third cooling compressor unit 903, the outlet of the third cooling compressor unit 903 is connected to the inlet of the fourth cooling compressor unit 904, and the outlet of the fourth cooling compressor unit 904 is connected to the inlet of the separation unit 4.

[0080] like Figure 4 As shown, a quenching method for preliminary fractionation of cracked gas is provided. The quenching method is adapted to a quenching system and includes: S101. The cracked gas is subjected to a first rapid cooling using quenching oil to obtain a first cracked gas, a heavy fuel oil component, and a light fuel oil component crude product. S102. The crude light fuel oil component is subjected to fuel oil stripping to obtain the light fuel oil component; S2. The first pyrolysis gas is subjected to a second quench cooling using quench water to obtain a first reflux material and a second pyrolysis gas; wherein the first reflux material is reused in the first quench cooling. S3. The second cracked gas is sequentially compressed, condensed, and stripped of light hydrocarbons to obtain the third cracked gas, the second reflux material, and the first cracked gasoline; wherein the second reflux material is reused in the first quench cooler. S4. The third cracked gas is compressed and separated sequentially to obtain the second cracked gasoline; S5. Combine the first cracked gasoline and the second cracked gasoline to obtain cracked gasoline; S6. The cracked gasoline is subjected to deoctane treatment to obtain C9-rich cracked gasoline and third reflux material; wherein the third reflux material is recycled in the first quench.

[0081] The mass m1 of the first reflux material and the mass m2 of the second cracked gas satisfy m1:m2=1:2.2; The mass m3 of the second reflux material and the mass m4 of the third cracked gas satisfy the following: m3:m4=1:73; The mass m5 of the third reflux material and the mass m6 of the C9-rich cracked gasoline satisfy the following ratio: m5:m6=1:40.

[0082] The temperature of the first rapid cooling is 140℃; The second rapid cooling temperature is 80℃.

[0083] The stripping temperature for light hydrocarbons is 60℃; The temperature for the deoctane treatment was 93°C.

[0084] The pressure for the first rapid cooling is 0.2 MPa.

[0085] The pressure for light hydrocarbon stripping is 0.15 MPa; The compression pressure is 3 MPa; The pressure for the deoctane treatment is 0.1 MPa.

[0086] Example 2 Compared to Example 1, the differences in this example are as follows, while the rest are the same: The mass m1 of the first reflux material and the mass m2 of the second cracked gas satisfy the following: m1:m2=1:2; The mass m3 of the second reflux material and the mass m4 of the third cracked gas satisfy the following: m3:m4=1:50; The mass m5 of the third reflux material and the mass m6 of the C9-rich cracked gasoline satisfy the following ratio: m5:m6=1:20.

[0087] The temperature of the first rapid cooling is 100℃; The second rapid cooling temperature is 60℃.

[0088] The stripping temperature for light hydrocarbons is 50℃; The temperature for deoctane treatment is 50°C.

[0089] The pressure for the first rapid cooling is 0.3 MPa.

[0090] The pressure for stripping light hydrocarbons is 0.3 MPa; The compression pressure is 5 MPa; The pressure for the deoctane treatment is 0.2 MPa.

[0091] Example 3 Compared to Example 1, the differences in this example are as follows, while the rest are the same: The mass m1 of the first reflux material and the mass m2 of the second cracked gas satisfy the following: m1:m2=1:5; The mass m3 of the second reflux material and the mass m4 of the third cracked gas satisfy the following: m3:m4=1:80; The mass m5 of the third reflux material and the mass m6 of the initial distillation cracked gas satisfy the following ratio: m5:m6=1:50.

[0092] The temperature of the first rapid cooling is 200℃; The second rapid cooling temperature is 90℃.

[0093] The stripping temperature for light hydrocarbons is 150℃; The temperature for the deoctane treatment is 200℃.

[0094] The pressure of the first rapid cooling is 0.1 MPa.

[0095] The stripping pressure for light hydrocarbons is 0.1 MPa; The compression pressure is 1 MPa; The pressure for the deoctane treatment is 0.05 MPa.

[0096] Comparative Example 1 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: No second or third reflow is performed.

[0097] Comparative Example 2 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: No third reflux is performed.

[0098] Comparative Example 3 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: The mass m3 of the second reflux material and the mass m4 of the third cracked gas satisfy the following: m3:m4=1:90; The mass m5 of the third reflux material and the mass m6 of the initial distillation cracked gas satisfy the following ratio: m5:m6=1:60.

[0099] The content of light components below C9 in the products of each embodiment and comparative example was statistically analyzed, and the results are shown in Table 1.

[0100] Table 1. Content of light components in the products of each embodiment and comparative example.

[0101] As shown in Table 1, the quench system for preliminary fractionation of cracked gas provided in this application embodiment achieves control over the light component content in the quench oil tower through a synergistic design of "reflux to enhance separation efficiency + stepwise directional transfer of light components + low-light component reflux to block accumulation". The light component content in the final product is below 0.22%.

[0102] Compared to Example 1, Comparative Example 1 did not use the second and third reflux, which resulted in an excessive amount of light components in the light hydrocarbon stripping and deoctane treatment, leading to an excessive amount of light components in the final product; Comparative Example 2 did not use the third reflux, which resulted in an excessive amount of light components in the deoctane treatment, leading to an excessive amount of light components in the final product.

[0103] Compared to Example 1, the proportions of the second and third reflux materials in Comparative Example 3 were too low, which resulted in an excessive amount of light components in the light hydrocarbon stripping and deoctane treatment, leading to an excessive amount of light components in the final product. In summary, the quench system for preliminary fractionation of cracked gas provided in this application embodiment achieves precise control of the light component content of quench oil tower 1 through three core mechanisms: enhanced separation by reflux, stepwise transfer of light components, and reflux replenishment of low light components, so that the light component content in the final product is below 0.22%.

[0104] In addition, the present application provides a quench system for the preliminary fractionation of cracked gas. This quench system can effectively control the top temperature of the quench oil tower 1, prevent excessive light fuel oil heavy components from being carried into the downstream system, and improve the efficiency of the quench system. At the same time, the quench system can also control the amount of light fuel oil produced and effectively recover gasoline-like substances, improve resource utilization, and reduce energy consumption.

[0105] In addition, the present application provides a quench system for preliminary fractionation of cracked gas. This quench system can effectively control the component content of cracked gasoline, so that the content of C8 and C9 components in the reflux component can meet the reflux requirements of quench oil tower 1 while improving the reflux effect, further preventing the heavy components of light fuel oil from being carried into the downstream system, and realizing the control of the light component content of quench oil tower 1.

[0106] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A quenching system for the preliminary fractionation of cracked gas, the quenching system comprising: The quench stripping unit includes a quench oil tower, a quench water tower, and a light hydrocarbon stripping tower. The top of the quench oil tower is connected to the bottom of the quench water tower, and the top of the quench water tower is connected to the light hydrocarbon stripping tower. The product separation section includes a separation unit and a deoctane tower. The top outlet of the light hydrocarbon stripping tower is connected to the inlet of the separation unit. The outlet of the heavy hydrocarbon component of the separation unit and the outlet of the light hydrocarbon stripping tower are both connected to the inlet of the deoctane tower. The reflux unit includes a first reflux pipe, a second reflux pipe, and a third reflux pipe. The inlet of the first reflux pipe is connected to the bottom outlet of the quench water tower, and the outlet of the first reflux pipe is connected to the top inlet of the quench oil tower. The inlet of the second reflux pipe is connected to the bottom outlet of the light hydrocarbon stripping tower, and the outlet of the second reflux pipe is connected to the top inlet of the quench oil tower. The inlet of the third reflux pipe is connected to the bottom outlet of the deoctane tower, and the outlet of the third reflux pipe is connected to the top inlet of the quench oil tower.

2. The quenching system according to claim 1, characterized in that, The quench oil tower comprises, from top to bottom, a light fuel oil extraction section, a quench oil circulation section, and a flash evaporation section. The top outlet of the light fuel oil extraction section is connected to the bottom of the quench oil tower, and the bottom outlet of the light fuel oil extraction section is used to discharge light fuel oil components. The bottom outlet of the flash evaporation section is used to discharge heavy fuel oil components.

3. The quenching system according to claim 2, characterized in that, The quench stripping unit also includes a light fuel oil stripping tower, the inlet of which is connected to the bottom outlet of the light fuel oil extraction section to extract light fuel oil components.

4. The quenching system according to claim 1, characterized in that, The quench system also includes: The cooling and compression unit includes at least two cooling compressor units, at least one of the cooling compressor units being located between the top outlet of the light hydrocarbon stripping tower and the inlet of the separation unit, and at least one of the cooling compressor units being located between the top outlet of the quench water tower and the inlet of the light hydrocarbon stripping tower.

5. The quenching system according to claim 4, characterized in that, The cooling and compression unit includes a first cooling compressor unit, a second cooling compressor unit, a third cooling compressor unit, and a fourth cooling compressor unit. The inlet of the first cooling compressor unit is connected to the top outlet of the quench tower, the outlet of the first cooling compressor unit is connected to the inlet of the light hydrocarbon stripping tower, the inlet of the second cooling compressor unit is connected to the top outlet of the light hydrocarbon stripping tower, the outlet of the second cooling compressor unit is connected to the inlet of the third cooling compressor unit, the outlet of the third cooling compressor unit is connected to the inlet of the fourth cooling compressor unit, and the outlet of the fourth cooling compressor unit is connected to the inlet of the separation unit.

6. A quenching method for preliminary fractionation of cracked gas, said quenching method being adapted to the quenching system according to any one of claims 1 to 5, said quenching method comprising: The pyrolysis gas is first quenched using quench oil to obtain the first pyrolysis gas. The first pyrolysis gas is subjected to a second rapid cooling using quench water to obtain a first reflux material and a second pyrolysis gas; wherein the first reflux material is reused in the first rapid cooling. The second cracked gas is sequentially compressed, condensed, and stripped of light hydrocarbons to obtain a third cracked gas, a second reflux material, and a first cracked gasoline; wherein the second reflux material is reused in the first quenching process. The third cracked gas is compressed and separated sequentially to obtain the second cracked gasoline; The first pyrolysis gasoline and the second pyrolysis gasoline are combined to obtain pyrolysis gasoline; The cracked gasoline is subjected to deoctane treatment to obtain C9-rich cracked gasoline and a third reflux material; wherein the third reflux material is reused in the first quench.

7. The quenching method according to claim 6, characterized in that, The mass m1 of the first reflux material and the mass m2 of the second pyrolysis gas satisfy: m1:m2=1:(5 to 2); and / or The mass m3 of the second reflux material and the mass m4 of the third pyrolysis gas satisfy: m3:m4 = 1:(80 to 50); and / or The mass m5 of the third reflux material and the mass m6 of the C9-rich cracked gasoline satisfy the following: m5:m6=1:(50 to 20).

8. The quenching method according to claim 6, characterized in that, The temperature of the first rapid cooling is 100°C to 200°C; and / or The temperature of the second rapid cooling is 20°C to 90°C.

9. The quenching method according to claim 6, characterized in that, The temperature for stripping the light hydrocarbons is 30°C to 180°C; and / or The temperature for the deoctane treatment is from 40°C to 200°C.

10. The quenching method according to claim 6, characterized in that, The pressure of the first rapid cooling is 0.1 MPa to 0.3 MPa.

11. The quenching method according to claim 6, characterized in that, The pressure for stripping the light hydrocarbons is 0.1 MPa to 0.3 MPa; and / or The compression pressure is 1 MPa to 5 MPa; and / or The pressure of the deoctane treatment is from 0.05 MPa to 0.2 MPa.

12. The quenching method according to claim 5, characterized in that, The first quenching of the pyrolysis gas using quenching oil to obtain the first pyrolysis gas includes the following steps: The cracked gas is first quenched using quench oil to obtain first cracked gas, heavy fuel oil components and light fuel oil components crude products. The crude light fuel oil component is subjected to fuel oil stripping to obtain the light fuel oil component.

Images