Circulating chloropropene deacidification and dehydration device for preparing epoxy chloropropane by hydrogen peroxide method

Abstract

The utility model relates to a circulating chloropropene deacidification and dehydration device for preparing epoxy chloropropane by a hydrogen peroxide method, which comprises a main pipeline, a first adsorption tower, a second filter and a seventh on-off valve, discharging ports of the first adsorption tower and the second adsorption tower are connected with a first return pipe through pipelines, a first filter is installed on the first return pipe, a third on-off valve is installed at the position, close to one end, of the first return pipe, one end of the first return pipe is communicated with the main pipeline, and a fourth on-off valve is installed on the upstream of the connecting position of the first return pipe and the main pipeline. The device disclosed by the utility model is novel in structure, ingenious in conception, flexible to install and simple and convenient to operate, can realize removal of trace acid and water in circulating chloropropene, reduces the requirement of a subsequent unit on the corrosion resistance of equipment, avoids the influence of carried metal ions on the performance of a catalyst, and improves the safety and economical efficiency of device operation.

Description

Technical Field

[0001] The utility model relates to a dehydration device, in particular to a circulating chloropropene deacidification and dehydration device for epichlorohydrin production by hydrogen peroxide method. Background Technique

[0002] Epichlorohydrin (ECH) is an important chemical raw material. Most of it is used to produce epoxy resin, and it can also be used to manufacture synthetic glycerol, surfactants, etc. At the same time, epichlorohydrin is also an important chlorine-consuming product in chlor-alkali enterprises. In 2023, the global production capacity of epichlorohydrin reached 3.6 million tons / year, of which China had a production capacity of more than 1 million tons. With the rapid development of related industries such as new energy, the demand for epichlorohydrin will continue to increase. The production processes of epichlorohydrin mainly include the chlorohydrin method, the glycerol method, and the hydrogen peroxide method.

[0003] Almost all foreign countries adopt the chlorohydrin production process, but this method has a large amount of three wastes. For each ton of epichlorohydrin product, 40 tons of chlorine-containing wastewater and 1.2 tons of calcium chloride waste residue will be generated. In China, about 60% of the production capacity adopts the glycerol method, but this method also has relatively serious environmental problems, and almost all of China's glycerol depends on imports, with poor raw material autonomy. With the gradual deepening of environmental protection requirements, at the end of 2023, the National Development and Reform Commission issued the "Industrial Structure Adjustment Guidance Catalog (2024 Edition)", and the calcium method saponification process of epichlorohydrin was listed as a phased-out category (except when the fresh water consumption per ton of product does not exceed 15 tons and the waste residue generation does not exceed 100 kg by December 31, 2025). By then, a large number of chlorohydrin methods will face elimination, and the glycerol method needs to be combined with large chlor-alkali enterprises and related technologies such as catalytic wet oxidation to meet the relevant regulations.

[0004] The hydrogen peroxide method is a green, environmentally friendly, and economical route. This method can obtain epichlorohydrin products through a one-step reaction with chloropropene and hydrogen peroxide as the main raw materials, and its by-product is only water. To ensure the safety of the device operation, this process generally adopts an operation plan with excessive chloropropene. The excessive chloropropene will pass through the circulation recovery unit and return to the reactor to participate in the reaction again. Moreover, there are also side reactions such as hydrolysis and alcoholysis in the produced epichlorohydrin. The excessive chloropropene will also undergo hydrolysis to produce hydrochloric acid, which corrodes the equipment. Therefore, the separation of products and the removal of water and acid in the circulating chloropropene in the epichlorohydrin production route by hydrogen peroxide method are also very crucial.

[0005] CN103772327B discloses an extraction method of epichlorohydrin. In this method, a solution containing epichlorohydrin, methanol, allyl chloride and water is continuously extracted through two extraction towers. Using allyl chloride and water as extraction agents respectively, efficient separation of epichlorohydrin and methanol is achieved. The methanol content in the second raffinate phase rich in epichlorohydrin is less than 100 ppm. Using the above extraction method, most of the aqueous phase (water and methanol) and organic phase (allyl chloride and epichlorohydrin) in the mixture after reaction can be separated at a lower temperature, avoiding side reactions such as hydrolysis and alcoholysis caused by high temperature during conventional distillation operations, and ensuring the yield of epichlorohydrin products.

[0006] CN103772326B discloses a production method of epichlorohydrin. The disclosed method includes an epoxidation reaction process and an extraction process. The extraction process adopts the extraction process of the above CN103772327B, which solves the problem of the extraction rate of epichlorohydrin. However, in the actual operation process, it is found that there is still a relatively large amount of water in the organic phase, and its content is as high as 2000 ppm. Generally, when the water content in allyl chloride exceeds 100 ppm, allyl chloride and water will also undergo a hydrolysis reaction to produce hydrochloric acid, which seriously corrodes the equipment. Generally, corrosion-resistant materials need to be selected, increasing the equipment investment. Moreover, it will also cause the metal ion content in the recycled allyl chloride to be too high, affecting the reaction performance and even the activity and stability of the catalyst. Therefore, controlling the water content in the recycled allyl chloride and removing trace water in allyl chloride can protect the production equipment, reduce the material cost, improve the reaction performance and the catalyst life, and increase the economy of the device. Utility Model Content

[0007] In view of the above situation, to overcome the defects of the prior art, the present utility model provides a device for removing acid and water from recycled allyl chloride in the production of epichlorohydrin by the hydrogen peroxide method, which effectively solves the problems mentioned in the above background technology.

[0008] To achieve the above object, the present utility model provides the following technical solutions: The present utility model includes a main pipeline, a first adsorption tower, a second adsorption tower, a first on-off valve, a first return pipe, a second on-off valve, a first filter, a third on-off valve, a fourth on-off valve, a feed inlet, a discharge outlet, a third adsorption tower, a fourth adsorption tower, a fifth on-off valve, a second return pipe, a sixth on-off valve, a second filter, and a seventh on-off valve. One side of the main pipeline is respectively installed with a first adsorption tower and a second adsorption tower through pipelines. The discharge outlets of the first adsorption tower and the second adsorption tower are connected to a first return pipe through pipelines. A first filter is installed on the first return pipe. A third on-off valve is installed at a position near one end of the first return pipe. One end of the first return pipe is communicated with the main pipeline. A fourth on-off valve is installed upstream of the connection between the first return pipe and the main pipeline. The main pipeline is respectively installed with a third adsorption tower and a fourth adsorption tower through pipelines on one side of the first return pipe. The discharge outlets of the third adsorption tower and the fourth adsorption tower are connected to a second return pipe through pipelines. A sixth on-off valve is installed on the pipeline of the discharge outlets of the third adsorption tower and the fourth adsorption tower. A second filter is installed on the second return pipe. One end of the second filter is communicated with the main pipeline.

[0009] Preferably, first on-off valves are respectively installed on the pipelines between the main pipeline and the supports of the first adsorption tower and the second adsorption tower.

[0010] Preferably, second on-off valves are respectively installed on the pipelines between the first adsorption tower and the second adsorption tower and the first return pipe.

[0011] Preferably, a feed inlet is provided at one end of the main pipeline, and a discharge outlet is provided at the other end of the main pipeline.

[0012] Preferably, fifth on-off valves are respectively installed on the pipelines between the main pipeline and the third adsorption tower and the fourth adsorption tower.

[0013] Preferably, a seventh on-off valve is installed on the main pipeline upstream of the second return pipe and downstream of the pipelines between the third adsorption tower and the fourth adsorption tower and the main pipeline.

[0014] Beneficial effects: The structure of the present utility model is novel, the concept is ingenious, the installation is flexible, and the operation is simple. It can realize the removal of trace acid and water in circulating allyl chloride, reduce the requirement of the subsequent unit for the anti-corrosion performance of the equipment, avoid the influence of the carried metal ions on the performance of the catalyst, and improve the safety and economy of the device operation. Description of the Drawings

[0015] The drawings are used to provide a further understanding of the present utility model and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0016] Figure 1It is a schematic diagram of the overall structure of the present utility model;

[0017] Reference numerals in the figure: 1, main pipeline; 2, first adsorption tower; 3, second adsorption tower; 4, first on-off valve; 5, first return pipe; 6, second on-off valve; 7, first filter; 8, third on-off valve; 9, fourth on-off valve; 10, feed inlet; 11, discharge outlet; 12, third adsorption tower; 13, fourth adsorption tower; 14, fifth on-off valve; 15, second return pipe; 16, sixth on-off valve; 17, second filter; 18, seventh on-off valve. Specific embodiments

[0018] The following will Figure 1 make a further detailed description of the specific embodiments of the present utility model in conjunction with the attached

[0019] Example 1, given by Figure 1 The present utility model provides a device for removing acid and water from recycled allyl chloride in the production of epichlorohydrin by the hydrogen peroxide method, including a main pipeline 1, a first adsorption tower 2, a second adsorption tower 3, a first on-off valve 4, a first return pipe 5, a second on-off valve 6, a first filter 7, a third on-off valve 8, a fourth on-off valve 9, a feed inlet 10, a discharge outlet 11, a third adsorption tower 12, a fourth adsorption tower 13, a fifth on-off valve 14, a second return pipe 15, a sixth on-off valve 16, a second filter 17 and a seventh on-off valve 18. One side of the main pipeline 1 is respectively installed with a first adsorption tower 2 and a second adsorption tower 3 through pipelines. The discharge outlets of the first adsorption tower 2 and the second adsorption tower 3 are connected to a first return pipe 5 through pipelines. A first filter 7 is installed on the first return pipe 5. A third on-off valve 8 is installed at a position close to one end of the first return pipe 5. One end of the first return pipe 5 is communicated with the main pipeline 1. A fourth on-off valve 9 is installed upstream of the connection between the first return pipe 5 and the main pipeline 1. The main pipeline 1 is respectively installed with a third adsorption tower 12 and a fourth adsorption tower 13 through pipelines on one side of the first return pipe 5. The discharge outlets of the third adsorption tower 12 and the fourth adsorption tower 13 are connected to a second return pipe 15 through pipelines. A sixth on-off valve 16 is installed on the pipeline of the discharge outlets of the third adsorption tower 12 and the fourth adsorption tower 13. A second filter 17 is installed on the second return pipe 15. One end of the second filter 17 is communicated with the main pipeline 1. The adsorbent in the first adsorption tower 2 and the second adsorption tower 3 is one or several of soda lime, montmorillonite, activated carbon, anhydrous copper sulfate, calcium chloride, etc. The adsorbent in the third adsorption tower 12 and the fourth adsorption tower 13 is one or several of alumina, silica gel, 3A molecular sieve, modified 3A molecular sieve, etc.

[0020] First on-off valves 4 are respectively installed on the pipelines between the main pipeline 1 and the first adsorption tower 2 and the second adsorption tower 3 brackets, which is convenient for controlling the on-off of the pipelines.

[0021] Second on-off valves 6 are respectively installed on the pipelines between the first adsorption tower 2 and the second adsorption tower 3 and the first return pipe 5, facilitating the control of the pipeline on-off.

[0022] One end of the main pipeline 1 is provided with a feed inlet 10, and the other end of the main pipeline 1 is provided with a discharge outlet 11, facilitating the feeding and discharging.

[0023] Fifth on-off valves 14 are respectively installed on the pipelines between the main pipeline 1 and the third adsorption tower 12 and the fourth adsorption tower 13, facilitating the control of the pipeline on-off.

[0024] A seventh on-off valve 18 is installed on the main pipeline 1 upstream of the second return pipe 15 and downstream of the pipelines between the third adsorption tower 12 and the fourth adsorption tower 13 and the main pipeline 1, facilitating the control of the pipeline on-off.

[0025] Working principle: When the utility model is in use, the main pipeline 1 is installed in front of the separation tower of allyl chloride and epichlorohydrin, including the first adsorption tower 2 and the second adsorption tower 3, the first filter 7, the third adsorption tower 12 and the fourth adsorption tower 13, and the second filter 17 connected in series in sequence. Among them, both the first adsorption tower 2 and the second adsorption tower 3 and the third adsorption tower 12 and the fourth adsorption tower 13 adopt the installation form of two towers A / B in parallel, which can realize the operation mode of one open and one standby. The fifth on-off valve 14 is opened, the seventh on-off valve 18 is closed, and the first adsorption tower 2, the second adsorption tower 3, the first filter 7, the third adsorption tower 12, the fourth adsorption tower 13 and the second filter 17 are enabled. The fifth on-off valve 14 is closed, the seventh on-off valve 18 is opened, and only the first adsorption tower 2, the second adsorption tower 3 and the first filter 7 are enabled. When the adsorbent in one of the adsorption towers is saturated, the material can be switched to another adsorption tower and the previous adsorption tower can be regenerated, realizing the long-term continuous and stable operation of the device.

[0026] Beneficial effects: The utility model has a novel structure, ingenious concept, flexible installation, simple operation, can realize the removal of trace acid and water in the recycled allyl chloride, reduces the requirement of the subsequent unit for the anti-corrosion performance of the equipment, avoids the influence of the carried metal ions on the performance of the catalyst, and improves the safety and economy of the device operation.

[0027] Through the personnel in this field, all the electrical components in this case are connected to their adapted power supplies through wires, and the appropriate controller and encoder should be selected according to the actual situation to meet the control requirements. For the specific connection and control sequence, the electrical connection should be completed according to the sequence of the working order of each electrical component in the following working principle. The detailed connection means are well-known technologies in this field. The following mainly introduces the working principle and process, and no further description of the electrical control will be made.

[0028] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A cyclic allyl chloride deacidification and dehydration device for preparing epichlorohydrin by hydrogen peroxide method, comprising a main pipeline (1), a first adsorption tower (2), a second adsorption tower (3), a first on-off valve (4), a first reflux pipe (5), a second on-off valve (6), a first filter (7), a third on-off valve (8), a fourth on-off valve (9), a feed inlet (10), a discharge port (11), a third adsorption tower (12), a fourth adsorption tower (13), a fifth on-off valve (14), a second reflux pipe (15), a sixth on-off valve (16), a second filter (17) and a seventh on-off valve (18), characterized in that: A first adsorption tower (2) and a second adsorption tower (3) are respectively installed on one side of the main pipeline (1) through pipelines; the discharge ports of the first adsorption tower (2) and the second adsorption tower (3) are connected to a first reflux pipe (5) through pipelines; a first filter (7) is installed on the first reflux pipe (5); a third on-off valve (8) is installed near one end of the first reflux pipe (5); one end of the first reflux pipe (5) is connected to the main pipeline (1); a fourth on-off valve (9) is installed upstream of the connection between the first reflux pipe (5) and the main pipeline (1); 9), a main pipeline (1) is located on one side of the first reflux pipe (5), and a third adsorption tower (12) and a fourth adsorption tower (13) are respectively installed through pipelines, the discharge ports of the third adsorption tower (12) and the fourth adsorption tower (13) are connected to the second reflux pipe (15) through pipelines, a sixth on-off valve (16) is installed on the pipelines of the discharge ports of the third adsorption tower (12) and the fourth adsorption tower (13), a second filter (17) is installed on the second reflux pipe (15), and one end of the second filter (17) is connected to the main pipeline (1).

2. The device for deacidification and dehydration of cyclic allyl chloride by preparing epichlorohydrin by hydrogen peroxide method according to claim 1, characterized in that: First on-off valves (4) are respectively installed on the main pipeline (1) and the pipelines of the first adsorption tower (2) and the second adsorption tower (3) brackets.

3. The device for deacidification and dehydration of cyclic allyl chloride by preparing epichlorohydrin by hydrogen peroxide method according to claim 1, characterized in that: A second on-off valve (6) is respectively installed on the pipeline between the first adsorption tower (2) and the second adsorption tower (3) and the first reflux pipe (5).

4. The device for deacidification and dehydration of cyclic allyl chloride by preparing epichlorohydrin by hydrogen peroxide method according to claim 1, characterized in that: One end of the main pipeline (1) is provided with a feed port (10), and the other end of the main pipeline (1) is provided with a discharge port (11).

5. The device for deacidification and dehydration of cyclic allyl chloride by preparing epichlorohydrin by hydrogen peroxide method according to claim 1, characterized in that: A fifth on-off valve (14) is installed on the pipelines between the main pipeline (1) and the third adsorption tower (12) and the fourth adsorption tower (13), respectively.

6. The device for deacidification and dehydration of cyclic allyl chloride by preparing epichlorohydrin by hydrogen peroxide method according to claim 1, characterized in that: The main pipeline (1) is located upstream of the second reflux pipe (15) and is provided with a seventh on-off valve (18) downstream of the pipeline between the third adsorption tower (12) and the fourth adsorption tower (13) and the main pipeline (1).

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