A propane delivery system

Abstract

This application discloses a propane conveying system, including a main connecting pipe for collecting and conveying propane produced from at least two methanol-to-olefins (MTO) units; a first pipeline connecting the main connecting pipe to a steam cracking unit, on which a first control valve is installed; and a second pipeline connecting a propane storage tank to the steam cracking unit, on which a second control valve is installed. The system is configured to allow direct propane supply to the steam cracking unit or supply from the propane storage tank by controlling the opening and closing states of the first and second control valves. This application's solution reduces the number of propane outlet pipes required for multiple MTO units, saving initial upfront construction investment. Furthermore, by controlling the opening and closing states of the first and second control valves, flexible switching between direct propane supply to the steam cracking unit and supply from the propane storage tank is achieved, avoiding supply limitations caused by the reliance on storage tank buffers for propane and ensuring the stability of feedstock supply to the downstream steam cracking unit.

Description

Technical Field

[0001] This application generally relates to the technical field of process flow in the methanol-to-olefins industry. More specifically, this application relates to a propane delivery system. Background Technology

[0002] In the coal-based new materials industry, methanol-to-olefins (MTO) units are one of the core production units. The propane produced by these units is an important byproduct and needs to be transported to downstream steam cracking units as raw materials or sold as products through a reasonable extraction, storage and feeding process. The rationality of this process directly affects the project's investment costs, operating energy consumption and production flexibility.

[0003] In existing technologies, companies typically have multiple methanol-to-olefins (MTO) units, along with supporting storage and transportation tank areas and downstream steam cracking units, forming a complete propane production-storage-feeding chain. Specifically, the multiple MTO units operate independently, with propane produced by each unit transported to the storage and transportation tank area via a separate external pipeline. The storage and transportation tank area is equipped with propane spherical tanks to buffer the propane produced by all units. After entering the spherical tanks for buffering, the propane needs to be repressurized by the propane feed pumps in the tank area before finally being transported to the downstream steam cracking unit as feedstock.

[0004] In the existing process, propane from the methanol-to-olefins unit to the steam cracking unit requires a path of individual external pipeline transport to each unit → buffering in spherical tanks → pressurized transport by secondary pumps. This means multiple units require separate independent outflow pipelines to meet their respective propane transport needs. However, the existing technology requires a separate propane outflow pipeline for each methanol-to-olefins unit, resulting in cumulative design, procurement, and construction costs for multiple pipelines. This significantly increases the initial upfront investment, failing to meet the industry's need for cost reduction and efficiency improvement. Furthermore, the propane spherical tanks in the storage and transportation area require regular annual inspections, during which they must be shut down. Since propane in the current process must be buffered in spherical tanks before being supplied to downstream units, the adjustment space for the entire propane transport and feedstock process is extremely limited when the tanks are shut down. This could affect the stability of the feedstock supply to the downstream steam cracking unit, potentially necessitating adjustments to the unit's load and restricting production continuity.

[0005] In view of this, there is an urgent need to provide a propane delivery system solution that can reduce costs while improving operational flexibility. Utility Model Content

[0006] In order to at least solve one or more of the technical problems mentioned above, this application proposes a propane delivery system scheme in several aspects.

[0007] This application provides a propane conveying system, comprising: a main connecting pipe for collecting and conveying propane produced from at least two methanol-to-olefins units; a first pipeline for connecting the main connecting pipe to a steam cracking unit, wherein a first control valve is provided on the first pipeline; and a second pipeline for connecting a propane storage tank to the steam cracking unit, wherein a second control valve is provided on the second pipeline; the propane conveying system is configured to enable direct propane supply to the steam cracking unit or supply from the propane storage tank by controlling the opening and closing states of the first and second control valves.

[0008] In some embodiments, the propane storage tank is located in a storage and transportation tank area, and the storage and transportation tank area includes at least one propane storage tank, which is connected to the main connecting pipe via a third pipeline.

[0009] In some embodiments, the load capacity of the main connecting pipe is not less than the sum of the maximum propane production of all methanol-to-olefins units.

[0010] In some embodiments, the methanol-to-olefins unit is also connected to an arm-mounted loading arm for storing propane products for external sale.

[0011] In some embodiments, the loading arm is located in the storage and transportation tank area and connected to the methanol-to-olefins unit via a third pipeline.

[0012] In some embodiments, the propane delivery system further includes a control unit for automatically controlling the opening and closing of the first control valve and the second control valve according to the operating status of the steam cracking unit.

[0013] By using the propane delivery system provided above, this embodiment of the application, through the setting of a main connecting pipe, a first pipeline, and a second pipeline, can reduce the number of propane outlet pipes individually configured for multiple methanol-to-olefins units, reduce the pipeline laying length and complexity, and thus save on the initial one-time construction investment of the project. Furthermore, by controlling the opening and closing states of the first and second control valves, flexible switching can be achieved between direct propane supply to the steam cracking unit and supply from the propane storage tank, avoiding supply limitations caused by the necessity of propane relying on storage tank buffering, and ensuring the stability of the feedstock supply to the downstream steam cracking unit. Attached Figure Description

[0014] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, and the same or corresponding reference numerals denote the same or corresponding parts, wherein: Figure 1 A schematic diagram of a propane delivery system according to an embodiment of this application is shown.

[0015] In the diagram: 100, Propane delivery system; 101. Main connecting pipe; 102. First pipeline; 103. Second pipeline; 104. Third pipeline; 105. First control valve; 106. Second control valve; 107. Methanol to olefins unit; 108. Steam cracking unit; 109. Propane storage tank. Detailed Implementation

[0016] 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, not all, of the embodiments of this application. 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.

[0017] It should be understood that the terms "comprising" and "including" used in the specification and claims of this application indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0018] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0019] As used in this specification and claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0020] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0021] like Figure 1As shown, in some embodiments, this application provides a propane delivery system 100, including: a main connecting pipe 101 for collecting and delivering propane produced by at least two methanol-to-olefins units 107; a first pipeline 102 for connecting the main connecting pipe 101 to the steam cracking unit 108, and the first pipeline 102 is provided with a first control valve 105; and a second pipeline 103 for connecting a propane storage tank 109 to the steam cracking unit 108, and the second pipeline 103 is provided with a second control valve 106; the propane delivery system 100 is configured to allow propane to be directly fed to the steam cracking unit 108 or fed from the propane storage tank 109 by controlling the opening and closing states of the first control valve and the second control valve.

[0022] The propane delivery system 100 provided in this application includes a main connecting pipe 101, a first pipeline 102, and a second pipeline 103. Specifically, the main connecting pipe 101 is used to collect and transport propane produced by at least two methanol-to-olefins (MTO) units 107. That is, each MTO unit 107 is connected to a branch pipe, and all branch pipes are connected to the main connecting pipe 101. The first pipeline 102 is a dedicated pipeline connecting the main connecting pipe 101 and the steam cracking unit 108. A first control valve 105 is provided on the first pipeline 102, which is used to open or close the connection between the main connecting pipe 101 and the steam cracking unit 108. The second pipeline 103 is used to connect the propane storage tank 109 and the steam cracking unit 108. A second control valve 106 is provided on the second pipeline 103, which is used to open or close the connection between the main propane storage tank 109 and the steam cracking unit 108.

[0023] In operation, when the steam cracking unit 108 is running normally, the second control valve 106 is closed and the first control valve 105 is opened. Propane from the methanol-to-olefins unit 107 can be directly supplied to the steam cracking unit 108 via the main connecting pipe 101 and the first pipeline 102, reducing the operation of the tank area feed pump and saving energy. When the steam cracking unit 108 is under reduced load or shut down for maintenance, the second control valve 106 is opened and the first control valve 105 is closed. Propane from the propane storage tank 109 can enter the steam cracking unit 108 via the second pipeline 103.

[0024] The propane delivery system 100 provided in this application can flexibly select the propane supply path by controlling the opening and closing states of the first control valve and the second control valve. It can directly supply propane to the steam cracking unit 108, or it can first buffer the propane through the storage and transportation tank area before supplying it. In addition, by consolidating the propane from multiple methanol-to-olefins units 107 into a single main connecting pipe 101, the number of external pipes in the system is reduced, the pipeline laying length and complexity are reduced, and the initial construction investment is saved.

[0025] It is worth noting that the main connecting pipe 101 and the first pipe 102 in this application can be one pipe or two pipes connected to each other. The specific form can be set according to the actual situation on site.

[0026] In one specific implementation, a propane storage tank 109 is located in a storage and transportation tank area, and the storage and transportation tank area includes at least one propane storage tank 109, which is connected to the main connecting pipe 101 via a third pipeline 104.

[0027] In this application, propane storage tank 109 is specifically located in the storage and transportation tank area. It is worth noting that, to accommodate the three methanol-to-olefins units 107, this storage and transportation tank area is equipped with two propane storage tanks 109. These propane storage tanks 109 perform the core storage function, namely, receiving and storing propane transported from the main connecting pipe 101 and the third pipeline 104. This connection method not only ensures the stable storage of propane in the storage and transportation tank area but also facilitates the subsequent distribution and use of propane. Through the third pipeline 104, propane can be flexibly transported between the main connecting pipe 101 and the storage and transportation tank area, further improving the flexibility and reliability of the entire system.

[0028] In one specific implementation, the load capacity of the main connecting pipe 101 is not less than the sum of the maximum propane production of all methanol-to-olefins units 107.

[0029] In the scheme of this application, the carrying capacity of the main connecting pipe 101 is not less than the sum of the maximum propane production of all methanol-to-olefins units 107. That is, the main connecting pipe 101 is designed with full consideration of the maximum load conditions during system operation, ensuring that even when all methanol-to-olefins units 107 are operating at maximum capacity, the main connecting pipe 101 can safely and stably collect and transport propane to the subsequent steam cracking unit 108 or storage tank area. This design not only improves the reliability of the system but also provides sufficient margin for possible future capacity expansion, avoiding the need for large-scale modifications due to insufficient pipeline carrying capacity.

[0030] In some embodiments, the methanol-to-olefins unit 107 is also connected to an loading arm for storing propane products for external sale. The loading arm is located in the storage tank area and is connected to the methanol-to-olefins unit 107 via a third pipeline 104.

[0031] In this application's scheme, the storage and transportation tank area also includes an loading arm, the core purpose of which is to hold propane for external sales operations. Furthermore, the loading arm in this scheme is not directly connected to the methanol-to-olefins unit 107, but rather indirectly connected via a third pipeline 104. That is, in this application's scheme, the third pipeline 104 can be selectively connected to either the loading arm or the propane storage tank 109.

[0032] Those skilled in the art will understand that in other solutions, the loading arm, propane storage tank 109, and main connecting pipe 101 may not be connected via the third pipeline 104, but rather via the original production line. That is, when the steam cracking unit 108 is reduced in load or shut down for maintenance, excess propane can be transported via the original production line to the propane storage tank 109 in the storage and transportation tank area for buffer storage. If propane products need to be sold externally, the original production line can also guide propane to the loading arm in the storage and transportation tank area.

[0033] In one specific implementation, the propane delivery system 100 further includes a control unit, which is used to automatically control the opening and closing of the first control valve and the second control valve according to the operating status of the steam cracking unit 108.

[0034] In this application, the propane delivery system 100 is also equipped with a control unit. The core function of this control unit is to automatically control the opening and closing of the first and second control valves according to the operating status of the steam cracking unit 108, so as to adapt to the feeding requirements under different operating conditions. Specifically, when the steam cracking unit 108 is in normal operation, the control unit can automatically close the second control valve and open the first control valve according to the operating status, so that the propane produced by the three methanol-to-olefins units 107 can be directly delivered to the steam cracking unit 108 through the main connecting pipe 101. When the steam cracking unit 108 is shut down for maintenance, the control unit can automatically adjust the opening and closing of the control valves according to this status change, so that the excess propane can be stored in the propane storage tank 109 in the storage and transportation tank area through the original production line, or sold externally through the loading arm. The control unit can automatically control the switching of control valves, flexibly selecting feeding from the pump in the storage and transportation tank area or feeding directly from the main connecting pipe 101, thereby ensuring the automation and stability of the entire feeding process.

[0035] Those skilled in the art will understand that in other embodiments, the propane delivery system 100 may not have a control system, and the opening of the first control valve 105 and the second control valve 106 can be manually controlled by the operator, which is also applicable to the scheme of this application.

[0036] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A propane delivery system (100), characterized in that, include: The main connecting pipe (101) is used to collect and transport propane produced by at least two methanol-to-olefins units (107); A first pipeline (102) is used to connect the main connecting pipe (101) and the steam cracking device (108), and a first control valve (105) is provided on the first pipeline (102); and The second pipeline (103) is used to connect the propane storage tank (109) and the steam cracking unit (108), and the second pipeline (103) is provided with a second control valve (106). The propane delivery system (100) is configured to allow propane to be directly supplied to the steam cracking unit (108) or supplied by the propane storage tank (109) by controlling the opening and closing states of the first control valve and the second control valve.

2. The propane delivery system (100) according to claim 1, characterized in that, The propane storage tank (109) is located in the storage and transportation tank area, and the storage and transportation tank area includes at least one propane storage tank (109), which is connected to the main connecting pipe (101) through a third pipeline (104).

3. The propane delivery system (100) according to claim 1, characterized in that, The capacity of the main connecting pipe (101) is not less than the sum of the maximum propane production of all methanol-to-olefins units (107).

4. The propane delivery system (100) according to claim 2, characterized in that, The methanol-to-olefins unit (107) is also connected to an arm-mounted loading arm, which is used to hold propane products for external sale.

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