Preparation method of PDMS-PP composite membrane and application of PDMS-PP composite membrane to MDI waste brine treatment

A PDMS-PP, composite membrane technology, applied in water/sewage treatment, water treatment parameter control, extraction water/sewage treatment, etc., can solve the problems of high investment, high energy consumption, large one-time investment, etc., to simplify the process flow and equipment investment, reduce energy consumption, and achieve the effect of recycling

Active Publication Date: 2019-08-02
WANHUA CHEMICAL (NINGBO) CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this scheme optimizes the process of the extraction section and reduces the subsequent processing load, it cannot essentially solve the problem of high energy consumption in the process route of extraction-gas stripping-oxidation-adsorption, and the process route has complex equipment structure, long process flow, and one-time Larger sex investment
[0006] To sum up, the existing process route for the treatment of waste brine produced in the production process of MDI mainly adopts the process route of extraction-gas stripping-oxidation, which generally has high energy consumption, high investment, complex equipment structure and long process flow. defect

Method used

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  • Preparation method of PDMS-PP composite membrane and application of PDMS-PP composite membrane to MDI waste brine treatment

Examples

Experimental program
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Effect test

Embodiment 1

[0041] A membrane extraction device, such as figure 1 shown. It includes a shell 1, an extractant inlet pipeline 4 and an extractant outlet pipeline 5 arranged on the shell; there are flanged heads 2 and 3 on both sides of the shell; the lower part of the head 2 is connected to a waste brine inlet pipeline 6 , the upper part of the head 2 is connected to the waste brine outlet pipeline 7; a number of baffle support plates 8 are arranged inside the housing, and an extraction membrane tube 9 prepared by using a PDMS-PP composite membrane; the inner diameter of the housing 1 is 2 m; the length of the extraction membrane tube 9 is 6m, inner diameter 15mm, wall thickness 0.4mm, the number of membrane tubes is 400; the distance between supporting baffles is 500mm.

[0042] The PDMS-PP composite membrane material used is prepared according to the following steps:

[0043] 1) Pretreatment of the PP support film: dry the 0.3mm thick PP support film at 50°C for 3 hours;

[0044] 2) P...

Embodiment 2

[0054] A kind of MDI waste brine, its composition includes: NaCl content 250g / L, aniline content 11000mg / L, diphenylmethanediamine and polyamine content 2500mg / L. Waste brine flow rate 60m 3 / h.

[0055] The membrane extraction device of this embodiment has the same structural size as that of Example 1, except that the PDMS-PP composite membrane of the extraction membrane tube material is prepared according to the following steps:

[0056] 1) Pretreatment of PP supporting base film: dry 0.3mmPP supporting film at 50°C for 6 hours, soak in water for 2 hours;

[0057] 2) Put the PP supporting base film obtained in step 1) into a PDMS mass fraction of 5% n-hexane solution and soak for 2 hours, take it out and dry it until no liquid drips out, put it in a vacuum oven and dry it at 90°C for 10 hours; Put the processed PP support base film into the plasma modification reaction chamber, replace the air in the reaction chamber with argon repeatedly, and keep the pressure at 2-4barg,...

Embodiment 3

[0065] A kind of MDI waste brine, its composition includes: NaCl content 250g / L, aniline content 12000mg / L, diphenylmethanediamine and polyamine content 1800mg / L. Waste brine flow rate 60m 3 / h.

[0066] The membrane extraction device of this embodiment has the same structural size as that of Embodiment 1, and the PDMS-PP composite membrane is prepared according to the method of Embodiment 1, the difference is that:

[0067] The pretreatment of the PP base film in step 1) is: soak the 0.4mm thick PP base film in n-hexane for 3h, and dry at 30°C for 5h;

[0068] In step 2), the solvent is n-octane, the glow discharge power of the plasma device is 18KW, and the irradiation time is 68h;

[0069] In step 3), polydimethylsiloxane PDMS is dissolved in n-hexane, and the mass fraction of PDMS is 70%.

[0070] In step 4), the thickness of the PDMS-PP composite film is 1mm.

[0071] According to the processing method of embodiment 1, the MDI waste brine is processed in the above-men...

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Abstract

The invention relates to a preparation method of a PDMS-PP composite membrane and application of the PDMS-PP composite membrane to MDI waste brine treatment. The preparation method comprises the following steps: pretreating a PP supporting base membrane, performing plasma treatment, preparing a silicone rubber membrane solution, coating the PP supporting base membrane with thesilicone rubber membrane solution, and drying to obtain the composite membrane. Waste brine treatment comprises the following steps: 1), conveying MDI waste brine into an extracting membrane tube of membrane extraction equipment, conveying an extractant into a shell layer of the membrane extraction equipment, and extracting to obtain crude brine, wherein the extracting membrane tube is produced from the PDMS-PP composite membrane; 2), mixing the crude brine with an oxidant, sending into an oxidation reactor, and reacting to obtain refined brine; 3), reducing excess oxidant in the refined brine by using a reducingagent to obtain qualified brine. A treatment method has the advantages of low energy consumption, simple technological process, low equipment investment and the like; by the treatment method, TOC in the waste brine can be treated till the concentration is lower than 10 ppm.

Description

technical field [0001] The invention belongs to the technical field of industrial waste brine treatment, and in particular relates to a preparation method of a PDMS-PP composite membrane and its application in the treatment of MDI waste brine. Background technique [0002] MDI is one of the main raw materials in the polyurethane industry. It is a well-known method in the industry to prepare polymethylenepolyphenylpolyamine (DAM) by reacting aniline and formaldehyde under an acidic catalyst, and then to react DAM with phosgene to synthesize MDI. In the process of preparing DAM from aniline and formaldehyde, a large amount of waste brine containing amine organic substances (aniline, diphenylmethanediamine and polyamine) will be produced. In the current technology, the waste brine must be extracted, stripped, and oxidized. Measures After advanced treatment, it is directly discharged or reused to the supporting chlor-alkali device of the MDI device for electrolysis. [0003] M...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/12B01D69/10B01D67/00B01D71/26B01D71/70C02F1/44C02F1/72C02F1/74C02F1/26C02F1/70C02F9/06C02F101/38C02F101/12
CPCB01D67/0011B01D69/105B01D69/12B01D69/125B01D71/26B01D71/70B01D2323/30B01D2323/46C02F1/26C02F1/44C02F1/4693C02F1/70C02F1/72C02F1/74C02F9/00C02F2101/12C02F2101/38C02F2209/02C02F2209/20C02F2209/29C02F2209/44
Inventor 崔成成赵东科陈奎吴雪峰王文博李永峰李超群
Owner WANHUA CHEMICAL (NINGBO) CO LTD
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