A system for preparing nonene by propylene oligomerization and a process thereof

Abstract

The application discloses a system for preparing nonene through propylene oligomerization and a process thereof, wherein the system comprises a shell-and-tube reactor, a de-propane column, a recycled propylene column, a pre-dimer column, a dimer column, a trimer column, a tetramer column and a tetramer separation column. In the application, fresh propylene, recycled propylene and recycled dimers are subjected to oligomerization reaction in the tube pass of the shell-and-tube reactor, after the reaction is completed, the mixture is separated and recycled, and the propylene is sent back to the shell-and-tube reactor, thereby reducing propylene consumption and improving reaction efficiency.

Description

Technical Field

[0001] This invention relates to the field of nonene production technology, and more particularly to a system and process for preparing nonene by propylene oligomerization. Background Technology

[0002] Nonene, a trimer of propylene, can be used as a component in high-octane gasoline additives. Nonene can also be used to manufacture nonylphenol, which is a raw material for the preparation of agricultural emulsifiers and detergents. Dodecene, a tetramer of propylene, also has a wide range of applications. For example, calcium dodecylphenol sulfide, which is produced by dodecene, is a good lubricant additive.

[0003] Nonene, a trimer of propylene nonene, is an important chemical product. It can be used as an additive in high-octane gasoline and in the synthesis of products such as nonylbenzene, nonylphenol, and decanol. Nonylphenol is an important raw material for the preparation of agricultural emulsifiers and detergents.

[0004] Industrially, during the oligomerization of propylene to prepare nonene, the oligomerization of propylene produces byproducts such as hexene and C12 olefins in addition to nonene, resulting in low selectivity for nonene.

[0005] In addition, in existing industrial projects, in order to avoid the accumulation of propane impurities in the raw material propylene within the system, a continuous discharge method is adopted, which wastes a large amount of propylene and also results in a high concentration of propane within the reaction system.

[0006] Therefore, in view of the above-mentioned defects of the prior art, a technical means is provided to redevelop the existing process method and reduce the consumption of propylene and heat energy. Summary of the Invention

[0007] To achieve the above objectives, this invention provides a system and process for preparing nonene by propylene oligomerization. By combining a tubular reactor and a separation tower, propylene discharged from the tubular reactor is recovered, thereby improving the utilization rate of propylene.

[0008] In a first aspect, the present invention provides a system for preparing nonene by oligomerization of propylene, comprising a tubular reactor, a propane removal tower, a propylene recovery tower, a pre-dimer tower, a dimer tower, a trimer tower, a tetramer tower, and a tetramer separation tower;

[0009] The tubular reactor includes a tube side and a shell side. The tube side is connected to the propylene feed pipe, and the shell side is connected to the water inlet pipe. The propylene feed pipe is connected to the activated water pipe.

[0010] The bottom of the tubular reactor is connected to the propane removal tower via a reactant discharge pipe. A water cutter is installed on the reactant discharge pipe. The propane removal tower is connected to the propylene recovery tower via a top discharge pipe. The propane removal tower is connected to the pre-dimer tower via a first bottom discharge pipe.

[0011] The top discharge pipe of the propylene recovery tower is connected to the tubular reactor, and a branch of the top discharge pipe of the propane removal tower is connected to the top discharge pipe of the propylene recovery tower.

[0012] The pre-dimer tower is connected to the dimer tower via the top discharge pipe of tower C6-8, and the pre-dimer tower is connected to the trimer tower via the bottom discharge pipe of the second tower; the dimer tower is connected to the tubular reactor via the top discharge pipe of tower C6.

[0013] The trimer tower is connected to the tetramer tower via the third tower bottom discharge pipe, and the tetramer tower is connected to the tetramer separation tower via the C10-12 tower top discharge pipe.

[0014] Preferably, the reactant discharge pipe is connected to the body of the propane removal tower.

[0015] Preferably, the propane stripper is connected to the body of the propylene recovery tower via a top discharge pipe.

[0016] Preferably, the depropanizer is connected to the body of the pre-dimerizer via a first bottom outlet pipe.

[0017] Preferably, the pre-dimer tower is connected to the tower body of the dimer tower via a C6-8 top discharge pipe.

[0018] Preferably, the pre-dimer tower is connected to the body of the trimer tower via a second tower bottom discharge pipe.

[0019] Preferably, the trimer tower is connected to the body of the tetramer tower via a third tower bottom outlet pipe.

[0020] Preferably, the tetramer tower is connected to the body of the tetramer separation tower via a C10-12 top discharge pipe.

[0021] Secondly, the present invention provides a process for preparing nonene by propylene oligomerization, using the above-mentioned system, specifically including the following steps:

[0022] Fresh propylene is mixed with activated water and undergoes oligomerization in the tube side of a tubular reactor. After the reaction is complete, the mixture is dehydrated and conveyed to the depropanizer, where it is separated into a C3 mixture and a mixture larger than C3. The steam generated in the shell side is used as a heat medium in the reboiler of one or more of the following: the depropanizer, the propylene recovery tower, the predimer tower, the dimer tower, the trimer tower, the tetramer tower, and the tetramer separation tower.

[0023] A portion of the C3 mixture is fed to a propylene recovery tower, where it is separated into propylene and propane, and the propylene is fed to the tubular reactor; another portion of the C3 mixture is fed to the tubular reactor.

[0024] The mixture with more than C3 is fed to the pre-dimerization tower, where it is separated into a mixture of C6-8 and a mixture with more than C9.

[0025] The C6-8 mixture is fed to the dimer tower, where it is separated into a dimer and a C7-8 mixture; the dimer is then fed to the tubular reactor.

[0026] The mixture with C9 or higher is fed to the trimer tower, where it is separated into a trimer and a mixture with C10 or higher.

[0027] The mixture with a C10 or higher concentration is fed to the tetramer tower, where it is separated into a C10-12 mixture and a mixture with a C12 or higher concentration.

[0028] The C10-12 mixture is fed to the tetramer separation tower, where it is separated into a C10-11 mixture and a tetramer.

[0029] Preferably, the operating temperature of the tubular reactor is 200-250°C, more preferably, the operating temperature is 220°C, and the operating pressure is 4.5-5.5 MPaG, more preferably, the operating pressure is 5.1 MPaG.

[0030] Preferably, the top temperature of the propane removal column is 10-30°C, further preferably, the top temperature is 20°C, the bottom temperature is 150-240°C, further preferably, the bottom temperature is 200°C, and the operating pressure of the propane removal column is 0.5-1.2 MPaG, further preferably, the operating pressure is 0.9 MPaG.

[0031] Preferably, the top temperature of the propylene recovery tower is 50-58°C, further, the top temperature is 53°C, the bottom temperature is 60-70°C, further, the bottom temperature is 63°C, and the operating pressure of the propylene recovery tower is 1.5-2.5 MPaG, further, the operating pressure is 2.1 MPaG.

[0032] Preferably, the top temperature of the pre-dimer tower is 70-85°C, further preferably, the top temperature is 77°C, the bottom temperature is 140-180°C, further preferably, the bottom temperature is 151°C, and the operating pressure of the pre-dimer tower is 0.02-0.1 MPaG, further preferably, the operating pressure is 0.07 MPaG.

[0033] Preferably, the top temperature of the dimer column is 50-65°C, further, the top temperature is 62°C, the bottom temperature is 90-150°C, further, the bottom temperature is 110°C, and the operating pressure of the dimer column is 0.02-0.1 MPaG, further, the operating pressure is 0.07 MPaG.

[0034] Preferably, the top temperature of the trimer column is 145-160°C, further preferably, the top temperature is 149°C, the bottom temperature is 200-220°C, further preferably, the bottom temperature is 213°C, and the operating pressure of the trimer column is 0.02-0.1 MPaG, further preferably, the operating pressure is 0.07 MPaG.

[0035] Preferably, the top temperature of the tetramer tower is 140-160°C, further, the top temperature is 153°C, the bottom temperature is 180-200°C, further, the bottom temperature is 186°C, and the operating pressure of the tetramer tower is 5-25 kPaG, further, the operating pressure is 20 kPaA.

[0036] Preferably, the top temperature of the tetramer separation tower is 140-145°C, further, the top temperature is 140°C, the bottom temperature is 175-190°C, further, the bottom temperature is 181°C, and the operating pressure of the tetramer tower is 5-25 kPaA, further, the operating pressure is 20 kPaA.

[0037] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0038] (1) The present invention is equipped with a propylene recovery unit. After purifying the impurity propane, the propylene is returned to the tubular reactor, which reduces propylene consumption, improves reaction efficiency, and also produces a small amount of pure propane as a byproduct.

[0039] (2) In this invention, a tubular reactor is used, with the process medium flowing through the tube side and the deionized water used for heat removal in the shell side. The generated steam is used for the reboilers of the propane removal tower, propylene recovery tower, pre-dimer tower, dimer tower, trimer tower, tetramer tower and tetramer separation tower, which greatly reduces energy consumption. Attached Figure Description

[0040] Figure 1 This is a flowchart of a process for preparing nonene by propylene oligomerization according to the present invention.

[0041] The markings in the diagram indicate the following:

[0042] 1-Tube reactor, 11-Propylene feed pipe, 12-Water inlet pipe, 13-Reactant outlet pipe, 2-Propane removal tower, 21-Propane removal tower top outlet pipe, 22-First tower bottom outlet pipe, 3-Propylene recovery tower, 31-Propylene recovery tower top outlet pipe, 4-Pre-dimer tower, 41-C6-8 tower top outlet pipe, 42-Second tower bottom outlet pipe, 5-Dimer tower, 51-C6 tower top outlet pipe, 6-Trimer tower, 61-Third tower bottom outlet pipe, 7-Tetramer tower, 71-C10-12 tower top outlet pipe, 8-Tetramer separation tower. Detailed Implementation

[0043] The present invention will now be described in detail and specifically through specific embodiments to enable a better understanding of the invention. However, the following embodiments do not limit the scope of the invention.

[0044] Example 1

[0045] This embodiment provides a system for preparing nonene by propylene oligomerization, such as... Figure 1 The system includes a tubular reactor 1, a propane removal tower 2, a propylene recovery tower 3, a pre-dimer tower 4, a dimer tower 5, a trimer tower 6, a tetramer tower 7, and a tetramer separation tower 8.

[0046] Specifically, the tubular reactor 1 includes a tube side and a shell side. The tube side is connected to the propylene feed pipe 11, which is also connected to the activation water pipe. The reactants are first mixed with pure water before entering the tubular reactor 1. This pure water is used to activate the catalyst. Solid acid catalyst particles are manually added to the tube side. The shell side is connected to the water inlet pipe 12, and the shell side is cooled with deionized water. The bottom of the tubular reactor 1 is connected to the propane removal tower 2 via the reactant discharge pipe 13. The propane removal tower 2 is connected to the propylene recovery tower 3 via the propane removal tower top discharge pipe 21. The propane removal tower 2 is connected to the pre-dimerization tower 4 via the first tower bottom discharge pipe 22.

[0047] The propylene recovery tower 3 has its top discharge pipe 31 connected to the tubular reactor 1, and a branch of the propane removal tower top discharge pipe 21 is connected to the propylene recovery tower top discharge pipe 31.

[0048] The pre-dimer tower 4 is connected to the dimer tower 5 via the C6-8 tower top discharge pipe 41, and the pre-dimer tower 4 is connected to the trimer tower 6 via the second tower bottom discharge pipe 42; the dimer tower is connected to the tubular reactor 1 via the C6 tower top discharge pipe 51.

[0049] The trimer tower 6 is connected to the tetramer tower 7 via the third tower bottom discharge pipe 61, and the tetramer tower 7 is connected to the tetramer separation tower 8 via the C10-12 tower top discharge pipe 71.

[0050] In this embodiment, the propylene feed pipe 11 is also equipped with a preheater to preheat the material in the propylene feed pipe 11.

[0051] Example 2

[0052] This embodiment provides a process for preparing nonene by propylene oligomerization, using the system in Example 1, and specifically includes the following steps:

[0053] Fresh propylene, recycled propylene, recycled dimer, and activated water are mixed and subjected to oligomerization in the tube side of tubular reactor 1. After the reaction is completed, the mixture is dehydrated and transported to the propane removal tower 2. In the top and bottom of the propane removal tower 2, it is separated into a C3 mixture and a mixture larger than C3. The steam generated in the shell side is used as a heat medium and applied to the reboiler of one or more of the tower bottoms of the propane removal tower 2, the propylene recovery tower 3, the pre-dimer tower 4, the dimer tower 5, the trimer tower 6, the tetramer tower 7, and the tetramer separation tower 8.

[0054] A portion of the C3 mixture is fed to the propylene recovery tower 3, where it is separated into propylene and propane at the top and bottom. The propylene is fed to the tubular reactor 1, and the propane is discharged to the outside for collection. Another portion of the C3 mixture is fed to the tubular reactor 1.

[0055] The mixture with C3 or greater is fed to the pre-dimer tower 4, where it is separated into a C6-8 mixture and a mixture with C9 or greater at the top and bottom of the pre-dimer tower 4.

[0056] The C6-8 mixture is fed to the dimer tower 5, where it is separated into a dimer and a C7-8 mixture at the top and bottom of the tower. The dimer is fed to the tubular reactor 1, while the C7-8 mixture is discharged to the outside for collection.

[0057] The mixture with C9 or higher is conveyed to the trimer tower 6, where it is separated into trimer and a mixture with C10 or higher at the top and bottom of the tower. The trimer is discharged to the outside for collection.

[0058] The mixture with a C10 or higher concentration is fed to the tetramer tower 7, where it is separated into a C10-12 mixture and a mixture with a C12 or higher concentration at the top and bottom of the tower. The mixture with a C12 or higher concentration is discharged to the outside for collection.

[0059] The C10-12 mixture is conveyed to the tetramer separation tower 8, where it is separated into a C10-11 mixture and a tetramer at the top and bottom of the tower, respectively, and then discharged to the outside for collection.

[0060] In this embodiment, the operating temperature of the tubular reactor 1 is 220°C and the operating pressure is 5.1 MPaG.

[0061] In this embodiment, the top temperature of the propane removal column 2 is 20°C, the bottom temperature is 200°C, and the operating pressure of the propane removal column is 0.9 MPaG.

[0062] In this embodiment, the top temperature of the propylene recovery tower 3 is 53°C, the bottom temperature is 63°C, and the operating pressure of the propane removal tower is 2.1 MPaG.

[0063] In this embodiment, the top temperature of the pre-dimer tower 4 is 77°C, the bottom temperature is 151°C, and the operating pressure is 0.07 MPaG.

[0064] In this embodiment, the top temperature of the dimer tower 5 is 62°C, the bottom temperature is 110°C, and the operating pressure of the propane removal tower is 0.07 MPaG.

[0065] In this embodiment, the top temperature of the trimer tower 6 is 149°C, the bottom temperature is 213°C, and the operating pressure of the propane dehydrogenator is 0.07 MPaG.

[0066] In this embodiment, the top temperature of the tetramer tower 7 is 153°C, the bottom temperature is 186°C, and the operating pressure of the propane removal tower is 20 kPaA.

[0067] In this embodiment, the top temperature of the tetramer separation tower 8 is 140°C, the bottom temperature is 181°C, and the operating pressure of the propane removal tower is 20 kPaA.

[0068] In this embodiment, the yield of nonene is >75%, and the yield of by-product dodecene is >5%.

[0069] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A system for preparing nonene by propylene oligomerization, characterized in that, This includes tubular reactors, propane stripping towers, propylene recovery towers, pre-dimer towers, dimer towers, trimer towers, tetramer towers, and tetramer separation towers; The tubular reactor includes a tube side and a shell side. The tube side is connected to the propylene feed pipe, and the shell side is connected to the water inlet pipe. The propylene feed pipe is connected to the activated water pipe. The bottom of the tubular reactor is connected to the propane removal tower via a reactant discharge pipe. A water cutter is installed on the reactant discharge pipe. The propane removal tower is connected to the propylene recovery tower via a top discharge pipe. The propane removal tower is connected to the pre-dimer tower via a first bottom discharge pipe. The top discharge pipe of the propylene recovery tower is connected to the tubular reactor, and a branch of the top discharge pipe of the propane removal tower is connected to the top discharge pipe of the propylene recovery tower. The pre-dimer tower is connected to the dimer tower via the top discharge pipe of tower C6-8, and the pre-dimer tower is connected to the trimer tower via the bottom discharge pipe of the second tower; the dimer tower is connected to the tubular reactor via the top discharge pipe of tower C6. The trimer tower is connected to the tetramer tower via the third tower bottom discharge pipe, and the tetramer tower is connected to the tetramer separation tower via the C10-12 tower top discharge pipe.

2. A process for preparing nonene by propylene oligomerization, applied to the system as described in claim 1, characterized in that, Specifically, the following steps are included: Fresh propylene is mixed with activated water and undergoes oligomerization in the tube side of a tubular reactor. After the reaction is complete, the mixture is dehydrated and conveyed to the depropanizer, where it is separated into a C3 mixture and a mixture larger than C3. The steam generated in the shell side is used as a heat medium in the reboiler of one or more of the following: the depropanizer, the propylene recovery tower, the predimer tower, the dimer tower, the trimer tower, the tetramer tower, and the tetramer separation tower. A portion of the C3 mixture is fed to a propylene recovery tower, where it is separated into propylene and propane, and the propylene is fed to the tubular reactor; another portion of the C3 mixture is fed to the tubular reactor. The mixture with more than C3 is fed to the pre-dimerization tower, where it is separated into a mixture of C6-8 and a mixture with more than C9. The C6-8 mixture is fed to the dimer tower, where it is separated into a dimer and a C7-8 mixture; the dimer is then fed to the tubular reactor. The mixture with C9 or higher is fed to the trimer tower, where it is separated into a trimer and a mixture with C10 or higher. The mixture with a C10 or higher concentration is fed to the tetramer tower, where it is separated into a C10-12 mixture and a mixture with a C12 or higher concentration. The C10-12 mixture is fed to the tetramer separation tower, where it is separated into a C10-11 mixture and a tetramer.

3. The process according to claim 2, characterized in that, The operating temperature of the tubular reactor is 200~250℃, and the operating pressure is 4.5~5.5MPaG.

4. The process according to claim 2, characterized in that, The top temperature of the propane removal column is 10~30℃, the bottom temperature is 150~240℃, and the operating pressure of the propane removal column is 0.5~1.2MPaG.

5. The process according to claim 2, characterized in that, The top temperature of the propylene recovery tower is 50~58℃, the bottom temperature is 60~70℃, and the operating pressure of the propylene recovery tower is 1.5~2.5MPaG.

6. The process according to claim 2, characterized in that, The top temperature of the pre-dimer tower is 70~85℃, the bottom temperature is 140~180℃, and the operating pressure of the pre-dimer tower is 0.02~0.1MPaG.

7. The process according to claim 2, characterized in that, The top temperature of the dimer column is 50~65℃, the bottom temperature is 90~150℃, and the operating pressure of the dimer column is 0.02~0.1MPaG.

8. The process according to claim 2, characterized in that, The temperature at the top of the trimer column is 145~160℃, the temperature at the bottom of the column is 200~220℃, and the operating pressure of the trimer column is 0.02~0.1MPaG.

9. The process according to claim 2, characterized in that, The temperature at the top of the tetramer tower is 140~160℃, the temperature at the bottom of the tower is 180~200℃, and the operating pressure of the tetramer tower is 5~25kPaA.

10. The process according to claim 2, characterized in that, The top temperature of the tetramer separation tower is 140~145℃, the bottom temperature is 175~190℃, and the operating pressure of the tetramer separation tower is 5~25kPaA.

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