Environment-friendly epoxypropane production device

Abstract

The utility model relates to an environment-friendly epoxypropane production device and belongs to the field of energy-saving and environment-friendly chemical equipment. The environment-friendly epoxypropane production device is characterized in that the production device comprises a chlorohydrination reaction device and a saponification reaction device located at the downstream of the chlorohydrination reaction device; the sedimentation device is positioned at the downstream of the saponification reaction device; the waste liquid recycling device and the filtering device are respectively positioned at the downstream of the sedimentation device; the filter residue recycling device is positioned at the downstream of the filtering device, and the discharging end of the filter residue recycling device is connected with the feeding end of the chlorohydrination reaction device. The production device disclosed by the utility model not only reduces the concentration of hydrogen chloride in a liquid-phase product of a chlorohydrination reaction and the dosage of lime milk in a saponification reaction, but also remarkably reduces the amount of filter residues needing to be additionally treated, so that the production efficiency is improved, environmental friendliness is promoted, more effective cost control is realized, and the production cost is reduced. Therefore, the production cost of the epoxypropane is greatly reduced, and the economic advantage is remarkable.

Description

Technical Field

[0001] The utility model relates to an environmentally friendly propylene oxide production device, belonging to the field of energy-saving and environmentally friendly chemical equipment. Background Art

[0002] Propylene oxide (PO) is an important basic organic chemical raw material and the third largest organic chemical product among propylene derivatives, second only to polypropylene and acrylonitrile. At present, the main industrial synthesis methods at home and abroad include chlorohydrin method, ethylbenzene co-oxidation method, isobutane co-oxidation method, hydrogen peroxide direct oxidation method (HPPO), etc.

[0003] In the above method, the process of producing propylene oxide by chlorohydrinization includes chlorohydrinization reaction and saponification reaction. Chlorohydrinization reaction is the reaction of chlorine with water to generate hydrogen chloride and hypochlorous acid, wherein hypochlorous acid reacts with propylene to produce chloropropanol, and chloropropanol is then saponified with calcium hydroxide to generate propylene oxide, calcium chloride and water. Although the method is technically mature, it will produce hypochlorous acid and hydrochloric acid that corrode equipment, and will also discharge a large amount of waste liquid and waste residue that seriously pollutes the environment. According to statistics, for every ton of propylene oxide produced, 1.374 tons of chlorine is consumed, and about 170 kg of by-product dichloropropane, about 0.6 tons of dry waste residue, and about 45 tons of waste water are produced.

[0004] Although there are reports of using dry waste residue for brick making or other building materials, it is still necessary to provide a more environmentally friendly propylene oxide production device to reduce waste emissions and their adverse effects on the environment, and on this basis improve the reaction efficiency, reduce waste residue emissions and treatment costs, thereby improving the environmental ecology and expanding the application prospects of this production method. Utility Model Content

[0005] In order to improve the above technical problems, the utility model provides a production device for propylene oxide, wherein the production device comprises:

[0006] A chlorohydrinization reaction unit, and a saponification reaction unit located downstream of the chlorohydrinization reaction unit;

[0007] A sedimentation device located downstream of the saponification reaction device, and a waste liquid recycling device and a filtering device respectively located downstream of the sedimentation device; and a filter residue recycling device located downstream of the filtering device, wherein the discharge end of the filter residue recycling device is connected to the feed end of the chlorohydrin reaction device.

[0008] According to the implementation scheme of the utility model, the chlorohydrin reaction device comprises a feed end and a discharge end, wherein the feed end comprises a feed port for feeding water, chlorine gas and filter residue, and the discharge end comprises a discharge port for producing chlorohydrin liquid.

[0009] According to an embodiment of the utility model, the saponification reaction device includes a feed end and a discharge end, wherein the feed end includes a feed port for feeding chlorohydrin liquid and lime milk, and the discharge end includes a discharge port for producing propylene oxide (such as crude propylene oxide), solid waste and waste liquid mixture.

[0010] According to the implementation scheme of the utility model, the production device further comprises a lime milk preparation device, and the discharge end of the lime milk preparation device is mixed with the chlorohydrin liquid produced by the chlorohydrin reaction device, so as to react in the saponification reaction device.

[0011] According to an embodiment of the utility model, the sedimentation device is used to sediment and separate the solid waste and waste liquid mixture generated by the saponification device. For example, the sedimentation device can be a sedimentation tank known in the art for sedimentation.

[0012] According to the implementation scheme of the utility model, the waste liquid recycling device is a pipeline for transporting the saponification residual liquid produced by the sedimentation device to the lime milk preparation device.

[0013] According to an embodiment of the utility model, the filtering device is used to further separate the wet solid waste generated by the sedimentation device to produce filter residue and clear liquid. For example, the filtering device is a filter press.

[0014] According to the implementation scheme of the utility model, the filter residue produced by the filtering device is mixed with water in the filter residue recycling device to obtain slurry.

[0015] According to the embodiment of the utility model, the slurry obtained in the filter residue recycling device can be directly pumped into the chlorohydrinization reaction device from the discharge end of the filter residue recycling device according to production needs; or, the slurry can also first enter a buffer device for storing slurry, and then be pumped into the chlorohydrinization reaction device. For this reason, the production device can also optionally set a buffer device between the filter residue recycling device and the chlorohydrinization reaction device.

[0016] According to the implementation scheme of the utility model, the buffer device may be provided with a stirring device and a pumping device for maintaining the solid-liquid mixed state of the slurry.

[0017] According to the implementation scheme of the utility model, the clear liquid generated by the filtering device can enter the waste liquid recycling device through a pipeline, and then be transported to the pipeline of the lime milk preparation device together with the saponification residual liquid; or, the clear liquid generated by the filtering device can also enter other post-treatment devices through a pipeline, such as entering the industrial water operation center for treatment.

[0018] According to an embodiment of the present utility model, the filter residue may contain one, two or more selected from oxides, hydroxides and carbonates of metal or non-metal elements.

[0019] According to an embodiment of the present invention, the metal or non-metal element can be selected from one, two or more of Ca, Mg, Fe, Al and Si.

[0020] According to an embodiment of the utility model, the filter residue may contain one, two or more selected from Ca(OH)2, CaCO3, MgCO3, Fe2O3, Al2O3, SiO2. For example, the filter residue may contain Ca(OH)2, CaCO3, MgCO3, Fe2O3, Al2O3 and SiO2.

[0021] According to an embodiment of the present invention, the filter residue may also contain CaSO4.

[0022] Those skilled in the art should understand that there is no particular limitation on the specific composition of the filter residue, as long as it is a filter residue produced by the process of preparing propylene oxide by the chlorohydrin method and has alkalinity.

[0023] According to the implementation scheme of the utility model, in the filter residue recycling device, the weight ratio of the dry weight of the filter residue to the water can be 1:5 to 1:10, such as 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0024] Those skilled in the art should understand that, according to production needs, the production device may further include connecting pipelines required for the purpose of transporting materials, pumps for providing pumping transmission power, and other necessary components known to those skilled in the art.

[0025] Beneficial Effects

[0026] The production device of the utility model not only reduces the concentration of hydrogen chloride in the liquid phase product of the chlorohydrin reaction and the amount of lime milk used in the saponification reaction, but also significantly reduces the amount of filter residue that requires additional treatment. Therefore, while improving production efficiency and promoting environmental friendliness, more effective cost control is also achieved, so that the production cost of propylene oxide of the utility model is also greatly reduced, and the economic advantage is significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the production device of the utility model, in which the various figure numbers have the following meanings: 1-chlorohydrin reaction device; 2-saponification reaction device; 3-sedimentation device; 4-filtration device; 5-filter residue recycling device; 6-waste liquid recycling device; 7-lime milk preparation device; 8-industrial water treatment device. DETAILED DESCRIPTION

[0028] The following will further describe the technical solution of the utility model in combination with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the utility model, and should not be interpreted as limiting the scope of protection of the utility model. All technologies implemented based on the above content of the utility model are included in the scope of protection of the utility model.

[0029] Example 1: Propylene oxide production device

[0030] The present embodiment provides a propylene oxide production device, wherein the production device comprises: a chlorohydrinization reaction device, and a saponification reaction device located downstream of the chlorohydrinization reaction device; a sedimentation device located downstream of the saponification reaction device, and a waste liquid recycling device and a filtering device respectively located downstream of the sedimentation device; and a filter residue recycling device located downstream of the filtering device, wherein a discharge end of the filter residue recycling device is connected to a feed end of the chlorohydrinization reaction device.

[0031] The chlorohydrin reaction device comprises a feed end and a discharge end, wherein the feed end comprises a feed port for feeding water, chlorine gas and filter residue, and the discharge end comprises a discharge port for producing chlorohydrin liquid.

[0032] The saponification reaction device comprises a feed end and a discharge end, wherein the feed end comprises a feed port for feeding chlorohydrin solution and lime milk, and the discharge end comprises a discharge port for producing crude propylene oxide, solid waste and waste liquid mixture.

[0033] The production device also includes a lime milk preparation device, and the discharge end of the lime milk preparation device is mixed with the chlorohydrin liquid produced by the chlorohydrin reaction device, so as to react in the saponification reaction device.

[0034] The sedimentation device is a sedimentation tank, which is used to sediment and separate the solid waste and waste liquid mixture generated by the saponification device.

[0035] The waste liquid recycling device is a pipeline used to transport the saponified residual liquid produced by the sedimentation device to the lime milk preparation device.

[0036] The filtering device is used to further separate the wet solid waste generated by the sedimentation device to produce filter residue and clear liquid.

[0037] The filter residue is mixed with water in the filter residue recycling device to obtain slurry. The slurry is pumped from the discharge end of the filter residue recycling device into the chlorohydrin reaction device.

[0038] The filter residue is produced by the process of preparing propylene oxide by the chlorohydrin method and is treated by a filter press. Based on the weight of the dry filter residue, the filter residue contains the following components in weight percentage (wt%):

[0039] Compound <![CDATA[Ca(OH)2]]> <![CDATA[CaCO3]]> <![CDATA[MgCO3]]> <![CDATA[Fe2O3]]> <![CDATA[Al2O3]]> <![CDATA[SiO2]]> <![CDATA[CaSO4]]> wt% 45～55 40～50 3～6 0.1～0.5 0.5～1 0.5～1 0.1～0.5

[0040] The filter residue recycling device includes a filter residue feed port, a water feed port, a mixing tank, and an output port. The filter residue is transported to the mixing tank, mixed with water at a weight ratio of 1:6, and stirred to form a slurry. The slurry is transported to a buffer tank equipped with a stirrer and a delivery pump for standby use.

[0041] The clear liquid can enter the waste liquid recycling device through a pipeline, and then be transported to the pipeline of the lime milk preparation device together with the saponification residual liquid; or, the clear liquid can also enter other post-treatment devices through a pipeline, such as entering the industrial water operation center for treatment.

[0042] The production device of the utility model not only reduces the concentration of hydrogen chloride in the liquid phase product of the chlorohydrin reaction and the amount of lime milk used in the saponification reaction, but also significantly reduces the amount of filter residue that requires additional treatment. Therefore, while improving production efficiency and promoting environmental friendliness, more effective cost control is also achieved, so that the production cost of propylene oxide of the utility model is also greatly reduced, and the economic advantage is significant.

[0043] The above is an exemplary description of the implementation of the technical solution of the utility model. It should be understood that the protection scope of the utility model is not limited to the above implementation. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the utility model shall be included in the protection scope of the claims of this application.

Claims

1. An environmentally friendly propylene oxide production device, characterized in that: The production device comprises: A chlorohydrinization reaction unit, and a saponification reaction unit located downstream of the chlorohydrinization reaction unit; A sedimentation device located downstream of the saponification reaction device, and a waste liquid recycling device and a filtering device respectively located downstream of the sedimentation device; and a filter residue recycling device located downstream of the filtering device, wherein the discharge end of the filter residue recycling device is connected to the feed end of the chlorohydrin reaction device.

2. An environmentally friendly propylene oxide production device as claimed in claim 1, wherein the chlorohydrin reaction device comprises a feed end and a discharge end, wherein the feed end comprises a feed port for feeding water, chlorine gas and filter residue, and the discharge end comprises a discharge port for producing chlorohydrin liquid.

3. A kind of environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the saponification reaction device comprises a feed end and a discharge end, wherein the feed end comprises a feed port for feeding chlorohydrin liquid and lime milk, and the discharge end comprises a discharge port for outputting propylene oxide, solid waste and waste liquid mixture.

4. An environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the production device also includes a lime milk preparation device, and the discharge end of the lime milk preparation device is mixed with the chlorohydrin liquid output by the chlorohydrin reaction device, thereby reacting in the saponification reaction device.

5. An environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the sedimentation device is used to sediment and separate the solid waste and waste liquid mixture generated by the saponification device.

6. An environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the waste liquid recycling device is a pipeline for transporting the saponification residual liquid produced by the sedimentation device to the lime milk preparation device.

7. An environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the filtering device is a filter press.

8. An environmentally friendly propylene oxide production device as claimed in claim 1 or 2, wherein the filter residue produced by the filtering device is mixed with water in the filter residue recycling device to obtain a slurry; The production device optionally includes a buffer device between the filter residue recycling device and the chlorohydrin reaction device.

9. An environmentally friendly propylene oxide production device as claimed in claim 8, wherein the buffer device is provided with a stirring device and a pumping device for maintaining a solid-liquid mixed state of the slurry.

10. An environmentally friendly propylene oxide production device as described in claim 1 or 2, wherein the clear liquid produced by the filtering device enters the waste liquid recycling device through a pipeline, and is then transported to the pipeline of the lime milk preparation device together with the saponification residual liquid; or, the clear liquid produced by the filtering device enters other post-treatment devices through a pipeline for treatment.

11. An environmentally friendly propylene oxide production device as claimed in claim 10, wherein the other post-treatment device is an industrial water operation center.

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