BDP acid washing, alkali washing and water washing system

Abstract

The utility model provides a BDP acid washing, alkali washing and water washing system. An outlet of a static mixer is connected with an inlet of a filter; an outlet of the filter is connected with an inlet of the centrifugal extractor, and an upper light-phase stream outlet of the centrifugal extractor is connected with an inlet of the coalescence separator. The method comprises the following steps: carrying out liquid-liquid contact on a BDP crude product, circulating diluted hydrochloric acid and a mixed solvent in a static mixer to remove impurities in the BDP crude product; the mixed water-oil mixed stream enters a filter for filtering and deslagging, and then enters a centrifugal extractor for primary extraction separation, so that primary separation of an organic phase and acid liquor is realized; a light-phase stream obtained after primary extraction separation enters a coalescence separator, and thorough separation of an organic phase and a trace amount of acid liquor is achieved; by adopting the scheme, alkali washing and water washing processes are carried out again. The device disclosed by the utility model can be used for most phosphate ester products so as to meet the requirements of low chroma and high purity of the products.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of purification process and purification device of BDP, specifically related to the related process and device of BDP using pickling, alkali washing, washing. BACKGROUND

[0002] Flame retardant BDP main performance one is containing higher phosphorus content and containing more benzene ring in molecule, with good flame retardant performance, two is molecular weight, volatility is small, structure is symmetrical and material compatibility is good, not easy to precipitate, flame retardant performance is durable, three is higher thermal decomposition temperature, thermal stability is better, can better satisfy material processing temperature requirement.Flame retardant BDP is mainly used for flame-retardant PC, PC / ABS plastic alloy, PPO, PPO / HIPS plastic alloy and epoxy resin and other materials.

[0003] BDP is colorless or light yellow liquid, insoluble in water, with dichloromethylbenzene, toluene, methanol, methylcyclohexane and methyl ethyl ketone and other organic solvents are soluble.BDP production process crude product contains a large amount of unreacted raw material, byproduct and other impurity components, generally needs to be pickled, alkali washed, washed and other multi-pass washing treatment, after washing, organic phase and water phase are separated, to improve the purity and quality of product.The existing traditional washing process is first dissolved and dispersed by adding organic solvent, then pickling is carried out to remove catalyst, BDP crude product is uniformly mixed with mixed solvent and is transferred into pickling kettle, after stirring and washing for a certain time, it is statically layered, organic phase is transferred into alkali washing kettle, and the washing temperature is controlled above 50~70℃;Then, phenol and acidic organic impurities are removed by alkali washing, alkali is quantitatively added into the alkali washing kettle, and the pickling organic material is transferred in, after stirring and washing, it is statically layered, and the organic phase is transferred into water washing process, and the washing temperature is controlled at 50~70℃;Finally, water washing is carried out to remove alkali and salt, process water is quantitatively added into the water washing kettle, and the alkali washing organic material is transferred in, after stirring and washing, it is statically layered, and the organic phase is finally subjected to distillation to remove organic solvent to obtain BDP product.The whole washing process adopts kettle type batch process, which is complicated, time-consuming, and the separation of organic phase and water phase is not complete, not only low in working efficiency, but also large in equipment investment, complex in equipment structure and inconvenient to use. SUMMARY

[0004] In view of the above technical problems, the utility model provides a kind of BDP pickling, alkali washing, water washing system, the outlet of static mixer is connected with the inlet of filter;The outlet of filter is connected with the inlet of centrifugal extractor, and the upper light phase stream outlet of centrifugal extractor is connected with the inlet of coalescence separator.

[0005] The static mixer is lined with polytetrafluoroethylene, and the inside is filled with interlaced wave plates, and the wave plate material is selected from acid and alkali corrosion resistant materials such as titanium and zirconium.

[0006] The filter is selected from one of a plate-and-frame filter, a filter bag filter, a precision filter, and a cartridge filter device, and a residue discharge port is arranged at the bottom of the filter.

[0007] The lower heavy phase flow outlet of the centrifugal extractor is connected with the inlet of the circulating pump, and the outlet of the circulating pump is connected with the inlet of the static mixer; the centrifugal extractor is provided with a mixed material inlet in the middle part; and the centrifugal extractor is provided with a light phase overflow port in the upper part.

[0008] The coalescing separator is internally provided with a coalescing inner part, preferably any one of polyester fiber, glass fiber and polypropylene; and cavities are formed at the upper and lower ends of the coalescing separator, and the coalescing separator is provided with a top oil phase outlet and a bottom water phase outlet.

[0009] In the technical scheme of the utility model, the device should be understood as a whole, and the structure of the whole is used in the water washing process.

[0010] That is, the same structure is used in the processes of pickling, alkaline washing and water washing, the washed material is again introduced into the static mixer for alkaline washing after pickling, and the washed material is again introduced into the static mixer for water washing after alkaline washing.

[0011] In some embodiments, the processes of pickling, alkaline washing and water washing adopt the same structure, and the structures of pickling, alkaline washing and water washing are assembled in series in turn, and the processes of pickling, alkaline washing and water washing are performed in turn.

[0012] The system further comprises an alkaline washing system connected in series with the pickling system, the alkaline washing system has the same structure as the pickling system, and the top oil phase outlet in the pickling system is connected with the static mixer in the alkaline washing system.

[0013] The system further comprises a water washing system connected in series with the alkaline washing system, the water washing system has the same structure as the alkaline washing system and the pickling system, and the top oil phase outlet in the alkaline washing system is connected with the static mixer in the water washing system.

[0014] For the above technical scheme, the utility model further provides an acid pickling, alkaline washing and water washing process comprising the device, comprising the following steps:

[0015] (1) the BDP crude product, the circulating dilute hydrochloric acid and the mixed solvent are contacted in a static mixer, impurities in the BDP crude product are dissolved in the dilute hydrochloric acid or react with the dilute hydrochloric acid to be transferred to the water phase, so that the impurities in the BDP crude product are removed;

[0016] (2) the mixed water-oil mixed flow is filtered by a filter and then enters a centrifugal extractor for primary extraction separation, so that the organic phase and the acid liquid are preliminarily separated;

[0017] (3) the light phase flow after the primary extraction separation enters a coalescence separator, so that the organic phase and the trace acid liquid are completely separated;

[0018] the steps (1), (2) and (3) are repeated to carry out alkali washing;

[0019] the steps (1), (2) and (3) are repeated to carry out water washing, so that the BDP is purified.

[0020] It can be understood by a person skilled in the art that the device is used to realize the pickling process, the material after pickling is used to realize the alkali washing process again by the device, and the material after alkali washing is washed by water again to realize the water washing process. That is, the devices used in the pickling, alkali washing and water washing are the same as a whole, and only new solvents are not needed in the alkali washing and water washing processes.

[0021] In the step (1), the concentration of the circulating dilute hydrochloric acid is 1-15% by mass, and fresh dilute hydrochloric acid is added when the concentration is not enough; the mixed solvent is selected from one or a mixture of two of toluene, methylcyclohexane and methyl ethyl ketone. The mass ratio of the mixed solvent and the BDP crude product at the inlet of the static mixer is (1-1.5:1).

[0022] In the step (2), the centrifugal extraction is carried out under the condition of dilute hydrochloric acid at a rotation speed of 500-15000 rpm, and the mass concentration of the dilute hydrochloric acid is 1-20%; in the step (3), the filtering precision of the filter is 0.5-5 microns.

[0023] The operating pressure of the static mixer is 0.1-0.5 MPaG, and the operating temperature is 50-80℃; the pressure of the lower cavity of the coalescence separator is 0.1-0.5 MPaG, the operating temperature is 50-80℃, the pressure of the upper cavity is 0.05-0.2 MPa, the temperature is 50-80℃, and the pressure difference between the upper and lower cavities is 0.1-0.2 MPa; the residence time of the oil phase in the coalescence separator is 20-60 min, and preferably 20-40 min.

[0024] The repeated steps (1), (2), (3) of the alkali washing refer to that the BDP purified by acid washing is subjected to the alkali washing again by the process, and in the step (1) of the alkali washing process, 1-20% mass fraction of circulating dilute liquid alkali is added for mixing to realize the alkali washing purification of the BDP, and fresh liquid alkali is added when the concentration is insufficient.

[0025] The repeated steps (1), (2), (3) of the water washing refer to that the BDP purified by alkali washing is subjected to the water washing again by the process, and in the step (1) of the water washing process, circulating pure water is added for mixing to realize the water washing purification of the BDP, and fresh pure water is added when the water amount is insufficient.

[0026] The BDP crude product (colorless or light yellow liquid, containing a large amount of unreacted raw materials, by-products and other impurity components, which needs to be subjected to multiple washing treatments such as acid washing, alkali washing and water washing, and then the organic phase and the aqueous phase are separated to sequentially improve the purity and quality of the product) in the step (1) is insoluble in water and soluble in organic solvents such as toluene, methylcyclohexane and methyl ethyl ketone. In the utility model, the BDP crude product and the organic solvent are fully mixed in the static mixer (better than the traditional kettle type stirring mixing effect, short time), and the purpose is to increase the dispersity of the product without changing the original product properties so that the product can fully participate in the subsequent reaction.

[0027] The main shaft rotating speed of the high-speed dispersion system in the step (2) is 500-15000 rpm, and the mass concentration of the hydrochloric acid is 1-20%. The two are fully mixed and reacted by high-speed stirring in the high-speed dispersion system, the metal catalyst (such as magnesium chloride) in the crude product is fully removed by acid washing, and the impurities such as benzoquinone can be removed by chemical reaction, and this process has better effect than the traditional kettle type stirring mixing, and the time is short.

[0028] In the step (3), the separation filter element material of the coalescence filter is acid and alkali resistant and organic solvent resistant material such as polyester fiber, glass fiber and polypropylene, the working temperature is 0-100 DEG C, and the filtration precision is 0.1-5 microns. Under the temperature and pressure difference of the upper and lower cavities, the organic phase and the acid liquid are quickly separated by the coalescence filter. Compared with the traditional static phase separation, the time is short and the separation is more thorough.

[0029] The BDP purified by acid washing is subjected to the steps (1), (2), (3) again to perform the alkali washing, and in the step (1) of the alkali washing process, 5-20% mass fraction of liquid alkali is supplemented for dispersion to finally realize the alkali washing purification of the BDP.

[0030] In the alkali washing process, no additional mixing solvent is needed, but the washing process still starts with the mixing by the static mixer.

[0031] In some embodiments, the organic phase from the outlet of the acid washing system enters the static mixer through the inlet, the dilute alkali solution (i.e. the water phase inlet) enters the static mixer through the inlet, and the two are fully mixed and reacted in the static mixer, and the impurities such as phenols and a small amount of residual acid in the crude product are removed by chemical reaction through the alkali washing. This process has better mixing effect and shorter time than the traditional kettle type stirring.

[0032] Then the material enters the filter through the inlet, and the solid insoluble substances generated in the alkali washing process are removed to prevent the subsequent process from being blocked by the centrifugal extractor and the coalescing separator. The discharge port is a slag discharge port, and the waste slag enriched in the filter can be blown out and discharged through the nitrogen backflushing system.

[0033] The filtrate enters the coalescing separator, and the separation of the organic phase and the alkali solution is quickly realized through the coalescing separator under the action of the temperature and pressure difference of the upper and lower cavities. This process is shorter in time and more thorough than the traditional static separation.

[0034] In some embodiments, the alkali washing system is at least a one-stage alkali washing system, and when it is a two-stage or more than two-stage alkali washing system, the organic phase from the outlet enters the two-stage alkali washing system, i.e. the complete washing process of the static mixer, the filter, the centrifugal extractor and the coalescing separator is performed again.

[0035] In some embodiments, the organic phase from the outlet of the alkali washing system (or the multi-stage alkali washing system after multi-stage alkali washing) enters the static mixer through the inlet, pure water enters the static mixer through the inlet (i.e. the water phase inlet), and the two are fully mixed and reacted in the static mixer, and the impurities such as residual alkali and salts after the two-stage alkali washing are removed by water washing. This process has better mixing effect and shorter time than the traditional kettle type stirring.

[0036] No solvent is added in the water washing process, but the static mixer is still used for mixing.

[0037] Then the material enters the filter through the inlet, and the solid insoluble substances that may exist in the water washing process are removed to prevent the subsequent process from being blocked by the coalescing separator. The discharge port is a slag discharge port, and the waste slag enriched in the filter can be blown out and discharged through the nitrogen backflushing system.

[0038] The filtrate enters the coalescing separator, and the separation of the organic phase and the water phase is quickly realized through the coalescing separator. This process is shorter in time and more thorough than the traditional static separation.

[0039] In some embodiments, the water washing system is at least a one-stage water washing system, and when it is a two-stage or more than two-stage water washing system, the organic phase from the outlet enters the two-stage water washing system, i.e. the complete washing process of the static mixer, the filter, the centrifugal extractor and the coalescing separator is performed again.

[0040] The technical scheme of the utility model has the following beneficial effects:

[0041] The utility model discloses a BDP pickling, caustic washing, water washing system, the static mixer M1's export is connected with the filter F1's import, the filter F1's export is connected with the centrifugal extractor M2's import, and the centrifugal extractor M2's upper light phase stream export is connected with the coalescence separator D1's import. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is the pickling process flow diagram of the utility model.

[0043] Figure 2 It is the caustic washing or water washing process flow diagram of the utility model.

[0044] M1 is static mixer, F1 is filter, M2 is centrifugal extractor, D1 is coalescence separator, P1 is pump, (1) is mixed solvent, (2) is circulating dilute hydrochloric acid, (3) is BDP crude product, (4) is water oil mixed stream, (5) is filtered water oil mixed stream, (6) is filter residue, (7) is light phase stream, (8) is heavy phase stream, (9) is heavy phase stream of discharge, (10) is fresh dilute hydrochloric acid, (11) is light phase stream, (12) is heavy phase stream of discharge. DETAILED DESCRIPTION

[0045] The utility model will be further described below in combination with specific embodiments. It should be understood that these embodiments are only used for illustrating the utility model and are not used for limiting the scope of the utility model. In addition, it should be understood that after reading the content taught by the utility model, those skilled in the art can make various changes or modifications to the utility model, and these equivalent forms also fall within the scope defined by the claims attached to the present application.

[0046] Embodiment 1

[0047] A kind of BDP pickling, caustic washing, water washing system, static mixer M1's export is connected with the filter F1's import;Filter F1's export is connected with the centrifugal extractor M2's import, and centrifugal extractor M2's upper light phase stream export is connected with the coalescence separator D1's import.

[0048] The static mixer M1 is lined with polytetrafluoroethylene and internally filled with interlaced corrugated plates made of acid and alkali corrosion resistant materials such as titanium.

[0049] The filter F1 is selected from one of a plate and frame filter, a filter bag filter, a precision filter, and a cartridge filter device, and the filter F1 is provided with a residue discharge port at the bottom. In this embodiment, a precision filter is taken as an example to perform the process.

[0050] The lower heavy phase stream outlet of the centrifugal extractor M2 is connected to the inlet of the circulating pump P1, and the outlet of the circulating pump P1 is connected to the inlet of the static mixer M1; the centrifugal extractor M2 is provided with a mixed material inlet in the middle; and the centrifugal extractor M2 is provided with a light phase overflow port at the upper portion.

[0051] The coalescing separator D1 is internally provided with coalescing internals, preferably any one of polyester fiber, glass fiber, and polypropylene; and cavities are formed at the upper and lower ends of the coalescing separator D1, and the coalescing separator is provided with a top oil phase outlet and a bottom water phase outlet.

[0052] The above process is used to perform the following BDP pickling, alkaline washing, and water washing steps:

[0053] Pickling:

[0054] (1) 60℃ BDP crude product (feed flow rate: 50 g / min), dilute hydrochloric acid with a mass fraction of 10% (feed flow rate: 15 g / min), and a mixture of 60℃ toluene and methylcyclohexane (feed flow rate: 100 g / min) are respectively introduced into the static mixer for liquid-liquid contact; the operating pressure of the static mixer is 0.3 MPaG, and the operating temperature is 70℃.

[0055] (2) After being uniformly mixed, the water-oil mixed stream is introduced into the filter to filter out the residue and then introduced into the centrifugal extractor for one-time extraction separation to realize the preliminary separation of the organic phase and the acid liquid, and 60℃ 10% dilute hydrochloric acid (feed flow rate: 15 g / min) is introduced into the centrifugal extractor; the filtration precision of the filter is 0.5~5 microns; and the centrifugal extraction is performed at a rotation speed of 5000 r / min.

[0056] (3) The light phase stream after one-time extraction separation is introduced into the coalescing separator, the coalescing separator is internally provided with polyester fiber coalescing internals, the pressure of the lower end cavity of the coalescing separator is 0.2 MPaG, the operating temperature is 70~80℃, the pressure of the upper end cavity is 0.05 MPa, and the temperature is 70~80℃; the oil phase residence time of the coalescing separator is 40 min, the complete separation of the organic phase and the trace acid liquid is realized; the acid liquid is discharged through the outlet, and the organic phase is introduced into the alkaline washing device through the outlet.

[0057] Alkaline washing:

[0058] (1) the organic phase (feed flow rate: 50 g / min) after pickling, the concentration of dilute liquid alkali is 10% (feed flow rate: 15 g / min) respectively into the static mixer for liquid-liquid contact; the operating pressure of the static mixer is 0.3 MPaG, and the operating temperature is 70℃;

[0059] (2) after mixing, the water-oil mixed stream enters the filter to filter out the residue and then enters the centrifugal extractor for primary extraction separation, so as to realize the preliminary separation of the organic phase and the acid liquor; the filtering precision of the filter is 0.5-5 microns; in the centrifugal extraction process, the rotation speed is 5000 r / min;

[0060] (3) the light phase stream after primary extraction separation enters the coalescence separator, the coalescence separator is internally provided with polyester fiber coalescence internals, the pressure of the lower cavity of the coalescence separator is 0.2 MPaG, the operating temperature is 70-80℃, the pressure of the upper cavity is 0.05 MPa, and the temperature is 70-80℃; the residence time of the oil phase in the coalescence separator is 40 min, so as to realize the thorough separation of the organic phase and the trace acid liquor; the alkali liquor is discharged through the outlet, and the organic phase enters the water washing device through the outlet.

[0061] Primary water washing:

[0062] (1) the organic phase (feed flow rate: 50 g / min) after alkali washing, the circulating pure water (feed flow rate: 15 g / min) respectively into the static mixer for liquid-liquid contact; the operating pressure of the static mixer is 0.3 MPaG, and the operating temperature is 70℃;

[0063] (2) after mixing, the water-oil mixed stream enters the filter to filter out the residue and then enters the centrifugal extractor for primary extraction separation, so as to realize the preliminary separation of the organic phase and the acid liquor; the filtering precision of the filter is 0.5-5 microns; in the centrifugal extraction process, the rotation speed is 5000 r / min;

[0064] (3) the light phase stream after primary extraction separation enters the coalescence separator, the coalescence separator is internally provided with polyester fiber coalescence internals, the pressure of the lower cavity of the coalescence separator is 0.2 MPaG, the operating temperature is 70-80℃, the pressure of the upper cavity is 0.05 MPa, and the temperature is 70-80℃; the residence time of the oil phase in the coalescence separator is 40 min, so as to realize the thorough separation of the organic phase and the trace acid liquor; the water phase is discharged through the outlet, and the organic phase enters the secondary water washing device through the outlet.

[0065] Secondary water washing:

[0066] (1) the organic phase (feed flow rate: 50 grams / min) after first water washing, circulating pure water (feed flow rate: 15 grams / min) are respectively into static mixer for liquid-liquid contact; the operating pressure of the static mixer is 0.3MPaG, and the operating temperature is 70 DEG C;

[0067] (2) after mixing, the water-oil mixed stream is filtered by a filter to filter out residues and then enters a centrifugal extractor for primary extraction separation, so that the organic phase and the acid liquor are preliminarily separated; the filtering precision of the filter is 0.5-5 microns; in the centrifugal extraction process, the rotation speed is 5000 revolutions / min;

[0068] (3) the light phase stream after the primary extraction separation enters a coalescence separator, polyester fiber coalescence internals are arranged in the coalescence separator, the pressure of the lower cavity of the coalescence separator is 0.2MPaG, the operating temperature is 70-80 DEG C, the pressure of the upper cavity is 0.05MPa, and the temperature is 70-80 DEG C; the residence time of the middle oil phase of the coalescence separator is 40 min, so that the organic phase and trace acid liquor are completely separated; the water phase is discharged through an outlet, and the organic phase is discharged through an outlet into a desolventizing system to remove organic solvents by distillation to obtain a BDP product.

[0069]

[0070] Not detected is less than 0.01ppm.

[0071] It can be seen that, compared with the existing washing process of BDP industrial production, the removal of catalyst, phenol and other organic impurities is obviously improved, and the product quality is improved.

Claims

1. A BDP acid washing, alkali washing and water washing system, characterized in that: The acid washing system in the system includes an outlet of a static mixer (M1) connected to an inlet of a filter (F1); the outlet of the filter (F1) is connected to an inlet of a centrifugal extractor (M2); and the upper light phase stream outlet of the centrifugal extractor (M2) is connected to an inlet of a coalescing separator (D1).

2. The BDP acid washing, alkali washing and water washing system according to claim 1, characterized in that: The static mixer (M1) is lined with polytetrafluoroethylene and filled with interlaced corrugated plates.

3. The BDP acid washing, alkali washing and water washing system according to claim 1, characterized in that: The filter (F1) is selected from a plate and frame filter, a filter bag filter, a precision filter, and a core filter device, and a slag discharge port is provided at the bottom of the filter (F1).

4. The BDP acid washing, alkali washing and water washing system according to claim 1, characterized in that: The lower heavy phase stream outlet of the centrifugal extractor (M2) is connected to the inlet of the circulation pump (P1), and the outlet of the circulation pump (P1) is connected to the inlet of the static mixer (M1).

5. The BDP acid washing, alkali washing and water washing system according to claim 4, characterized in that: A mixed material inlet is provided in the middle of the centrifugal extractor (M2); and a light phase overflow port is provided at the top of the centrifugal extractor (M2).

6. The BDP acid washing, alkali washing and water washing system according to claim 1, characterized in that: The coalescing separator (D1) is provided with coalescing internals; cavities are formed at the upper and lower ends of the coalescing separator (D1); and the coalescing separator is provided with a top oil phase outlet and a bottom water phase outlet.

7. The BDP acid washing, alkali washing and water washing system according to any one of claims 1 to 6, characterized in that: The system also includes an alkali washing system, which is connected in series with the pickling system. The alkali washing system and the pickling system have the same structure, and the top oil phase outlet in the pickling system is connected to the static mixer of the alkali washing system.

8. The BDP acid washing, alkali washing and water washing system according to claim 7, characterized in that: The system also includes a water washing system, which is connected in series with the alkali washing system. The water washing system has the same structure as the alkali washing system and the acid washing system, and the top oil phase outlet in the alkali washing system is connected to the static mixer of the water washing system.

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