Recycling device for by-products produced in preparation of epoxypropane by chlorohydrin method

Abstract

The utility model discloses a device for recycling by-products in preparation of epoxypropane by a chlorohydrin method, which comprises a dichloropropane recovery tank 1, a catalysis tower 2, a purification tower 3 and a propylene buffer tank 4, an inlet end of the dichloropropane recovery tank 1 is connected with a by-product conveying pipeline 5a in preparation of epoxypropane by the chlorohydrin method, and an outlet end of the dichloropropane recovery tank 1 is connected with an outlet end of the purification tower 3. The outlet end of the dichloropropane recovery tank 1 is connected into the catalytic tower 2; under the action of a catalyst in the catalysis tower 2, dichloropropane is subjected to a dechlorination reaction to generate propylene, and the propylene is conveyed to the purification tower 3 through the outlet end of the catalysis tower 2; the propylene is separated and purified by the purifying tower 3 and then is transferred into the propylene buffer tank 4 for later use; according to the device disclosed by the utility model, the recovery, conversion and utilization of the propylene oxide byproduct-dichloropropane prepared by the chlorohydrin method are realized, so that the utilization rate of the propylene oxide byproduct is maximized, the production cost is reduced, economic benefits are brought, and the current treatment situation of the dichloropropane is obviously improved.

Description

Technical Field

[0001] The utility model relates to the field of preparation of propylene oxide, in particular to a recycling device for by-products of preparing propylene oxide by a chlorohydrin process. Background Art

[0002] With the rapid development of industries such as polyether polyols, propylene glycol and various non-ionic surfactants, the industry's demand for propylene oxide is increasing. Among them, the use of the chlorohydrin method to produce propylene oxide will produce a large amount of by-products: dichloropropane.

[0003] However, the current utilization rate of dichloropropane is very low. Except for a very small amount used as a solvent and fumigant, most of the rest of dichloropropane is treated as waste, causing damage to the ecological environment. Therefore, the rational use of dichloropropane, a renewable resource, is a technical research topic that needs to be developed urgently and has significant economic and social benefits.

[0004] Therefore, the applicant hopes to seek technical solutions to improve the above technical problems. Summary of the invention

[0005] In view of this, the purpose of the utility model is to provide a recycling device for the by-product of preparing propylene oxide by the chlorohydrin method to address the deficiencies of the existing technology, thereby realizing the recovery, conversion and utilization of dichloropropane, a by-product of preparing propylene oxide by the chlorohydrin method, and maximizing its utilization rate, which not only reduces production costs and brings economic benefits, but also significantly improves the current treatment status of dichloropropane.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A device for recycling byproducts of preparing propylene oxide by the chlorohydrin process comprises a dichloropropane recovery tank, a catalytic tower, a purification tower and a propylene buffer tank, wherein:

[0008] The inlet end of the dichloropropane recovery tank is connected to a byproduct delivery pipeline for preparing propylene oxide by a chlorohydrin process, and the outlet end of the dichloropropane recovery tank is connected to a catalytic tower;

[0009] Under the action of the catalyst in the catalytic tower, dichloropropane undergoes a dechlorination reaction to generate propylene, which is then transported to the purification tower through the outlet end of the catalytic tower;

[0010] The propylene is separated and purified by the purification tower and then transferred to the propylene buffer tank for standby use.

[0011] Preferably, a first delivery pump is installed on the delivery pipeline between the dichloropropane recovery tank and the catalytic tower, and the dichloropropane in the dichloropropane recovery tank is delivered to the catalytic tower by the first delivery pump.

[0012] Preferably, a circulation pump is installed at the bottom of the catalytic tower, and the circulating pump enables the dichloropropane to circulate in the catalytic tower.

[0013] Preferably, the catalyst used in the catalytic tower is activated carbon and Fe2O3.

[0014] Preferably, the inlet end of the catalytic tower is arranged at its upper end, and the outlet end thereof is arranged at its lower end.

[0015] Preferably, the purification tower is a distillation tower.

[0016] Preferably, the distillation tower is a plate distillation tower.

[0017] Preferably, a second delivery pump is installed on the delivery pipeline between the catalytic tower and the purification tower, and the propylene generated in the catalytic tower is delivered to the purification tower through the second delivery pump.

[0018] Preferably, a third delivery pump is installed on the delivery pipeline between the purification tower and the propylene buffer tank, and the propylene separated and purified is delivered and transferred to the propylene buffer tank for standby use by the third delivery pump.

[0019] The utility model proposes to redesign and transform the production pipeline of preparing propylene oxide by the chlorohydrin method, modify the process of the dichloropropane line originally sent to the tank area, change it to send it to the dichloropropane recovery tank, and add a dichloropropane absorption catalytic device (i.e., a catalytic tower), the catalytic tower uses activated carbon and Fe2O3 as catalysts, so that the dichloropropane undergoes a dechlorination reaction in the catalytic tower to generate propylene, and the propylene is separated and purified to obtain a usable propylene product; thus, the device provided by the application realizes the recovery, conversion and utilization of dichloropropane, a by-product of preparing propylene oxide by the chlorohydrin method, so that the utilization rate is maximized, which not only reduces the production cost and brings economic benefits, but also significantly improves the current treatment status of dichloropropane. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a device for recycling by-products of preparing propylene oxide by a chlorohydrin process according to a specific implementation mode of the utility model. DETAILED DESCRIPTION

[0021] The utility model discloses a recycling device for preparing propylene oxide byproducts by chlorohydrin method, comprising a dichloropropane recovery tank, a catalytic tower, a purification tower and a propylene buffer tank, wherein the inlet end of the dichloropropane recovery tank is connected with a byproduct conveying pipeline for preparing propylene oxide by chlorohydrin method, and the outlet end of the dichloropropane recovery tank is connected with the catalytic tower; under the action of the catalyst in the catalytic tower, the dichloropropane undergoes a dechlorination reaction to generate propylene, which is transported to the purification tower through the outlet end of the catalytic tower; and the propylene is separated and purified by the purification tower and then transferred to the propylene buffer tank for standby use.

[0022] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] See also Figure 1 As shown, a recycling device for by-products of preparing propylene oxide by the chlorohydrin process comprises a dichloropropane recovery tank 1, a catalytic tower 2, a purification tower 3 and a propylene buffer tank 4, wherein the inlet end of the dichloropropane recovery tank 1 is connected to a by-product conveying pipeline 5a for preparing propylene oxide by the chlorohydrin process, and the outlet end of the dichloropropane recovery tank 1 is connected to the catalytic tower 2; under the action of the catalyst in the catalytic tower 2, the dichloropropane undergoes a dechlorination reaction to generate propylene, which is transported to the purification tower 3 through the outlet end of the catalytic tower 2; the propylene is separated and purified by the purification tower 3 and then transferred to the propylene buffer tank 4 for standby use; specifically preferably, in this embodiment, the catalyst used in the catalytic tower 2 is activated carbon and Fe2O3; preferably, in this embodiment, the purification tower 3 adopts a distillation tower, and specifically preferably adopts a plate distillation tower.

[0024] Preferably, in order to achieve efficient transportation of materials, in the present embodiment, a first delivery pump 6 is installed on the delivery pipeline 5b between the dichloropropane recovery tank 1 and the catalytic tower 2, and the dichloropropane in the dichloropropane recovery tank 1 is transported to the catalytic tower 2 by the first delivery pump 6; preferably, in the present embodiment, a second delivery pump (not shown) is installed on the delivery pipeline 5c between the catalytic tower 2 and the purification tower 3, and the propylene generated in the catalytic tower 2 is transported to the purification tower 3 by the second delivery pump; preferably, in the present embodiment, a third delivery pump (not shown) is installed on the delivery pipeline 5d between the purification tower 3 and the propylene buffer tank 4, and the propylene separated and purified is transported and transferred to the propylene buffer tank 4 for standby use by the third delivery pump.

[0025] Preferably, in order to further facilitate the dechlorination reaction of dichloropropane, in the present embodiment, a circulation pump 7 is installed at the bottom of the catalytic tower 2, and the circulation pump 7 enables the dichloropropane to circulate in the catalytic tower 2; preferably, in the present embodiment, the inlet end 2a of the catalytic tower 2 is arranged at its upper end, and the outlet end 2b thereof is arranged at its lower end.

[0026] This embodiment proposes to redesign and transform the production pipeline of preparing propylene oxide by the chlorohydrin method, modify the process of the dichloropropane line originally sent to the tank area, and change it to send it to the dichloropropane recovery tank, and at the same time add a dichloropropane absorption catalytic device (i.e., a catalytic tower), the catalytic tower uses activated carbon and Fe2O3 as catalysts, so that dichloropropane undergoes a dechlorination reaction in the catalytic tower to generate propylene, and the propylene is separated and purified to obtain a usable propylene product; thus, the device provided in this embodiment realizes the recovery, conversion and utilization of dichloropropane, a by-product of preparing propylene oxide by the chlorohydrin method, and maximizes its utilization rate, which not only reduces the production cost and brings economic benefits, but also significantly improves the current treatment status of dichloropropane.

[0027] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.

[0028] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A device for recycling by-products of preparing propylene oxide by the chlorohydrin process, characterized in that: It comprises a dichloropropane recovery tank (1), a catalytic tower (2), a purification tower (3) and a propylene buffer tank (4), wherein: The inlet end of the dichloropropane recovery tank (1) is connected to a byproduct delivery pipeline (5a) for preparing propylene oxide by the chlorohydrin process, and the outlet end of the dichloropropane recovery tank (1) is connected to a catalytic tower (2); Under the action of the catalyst in the catalytic tower (2), dichloropropane undergoes a dechlorination reaction to generate propylene, which is then transported to the purification tower (3) through the outlet of the catalytic tower (2); The propylene is separated and purified in the purification tower (3) and then transferred to the propylene buffer tank (4) for standby use.

2. The recycling device for preparing propylene oxide byproducts by the chlorohydrin process according to claim 1, characterized in that: A first delivery pump (6) is installed on the delivery pipeline (5b) between the dichloropropane recovery tank (1) and the catalytic tower (2), and the dichloropropane in the dichloropropane recovery tank (1) is delivered to the catalytic tower (2) by the first delivery pump (6).

3. The recycling device for preparing propylene oxide by-products by the chlorohydrin process according to claim 1, characterized in that: A circulation pump (7) is installed at the bottom of the catalytic tower (2), and the circulation pump (7) enables the dichloropropane to circulate in the catalytic tower (2).

4. The recycling device for preparing propylene oxide byproducts by the chlorohydrin process according to claim 1, characterized in that: The inlet end (2a) of the catalytic tower (2) is arranged at its upper end, and the outlet end (2b) is arranged at its lower end.

5. The recycling device for preparing propylene oxide byproducts by the chlorohydrin process according to claim 1, characterized in that: The purification tower (3) is a distillation tower.

6. The device for recycling by-products of preparing propylene oxide by the chlorohydrin process according to claim 5, characterized in that: The distillation tower is a plate type distillation tower.

7. The device for recycling by-products of preparing propylene oxide by the chlorohydrin process according to claim 1, characterized in that: A second delivery pump is installed on the delivery pipeline (5c) between the catalytic tower (2) and the purification tower (3), and the propylene generated in the catalytic tower (2) is delivered to the purification tower (3) through the second delivery pump.

8. The device for recycling by-products of preparing propylene oxide by the chlorohydrin process according to claim 1, characterized in that: A third delivery pump is installed on the delivery pipeline (5d) between the purification tower (3) and the propylene buffer tank (4), and the propylene that has been separated and purified is delivered to the propylene buffer tank (4) for standby use via the third delivery pump.

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