TWI224581B - Process for the purification of wash water from the production of aromatic acids - Google Patents

Abstract

An improved apparatus and method for the purification of waste wash water (20) derived from the production of aromatic acids. Lost aromatic acid product and the heavy metal oxidation catalyst is recovered and purified water is recycled to the process. The process includes the steps of filtration (10) to recover the insoluble aromatic acid (21), ion exchange (11) to recover and purify the heavy metal oxidation catalyst (12), and a reverse osmosis system (13) for recovering the water (14) for reuse.

Description

1224581 V. Description of the Invention (1) [Technical Field] The field of the present invention relates to a method for producing aromatic acids, in particular to a method for improving aromatic acids, which can recover products and heavy metal oxidation catalysts used for the production of certain aromatic acids. And process water. Aromatic acids include, but are not limited to, terephthalic acid (T A) and isophthalic acid (I P A). [Background technique]

Dickerson et al. (U.S. Patent No. 4,540,493) discloses a method for treating washing water obtained from the production of terephthalic acid. The method includes the following steps: washing water is passed through a filter medium to remove undissolved terephthalic acid solids, filtered water is passed through a cation exchange resin in the form of hydrogen to remove metal catalysts, and water is passed through an anion exchange resin to remove dissolved Terephthalic acid and dissolved organic acid by-products. However, the disadvantage of this method is that the use of cation I ER in the form of hydrogen may cause resin fouling because the hydrogen ions may react with soluble aromatic acids to cause precipitation and contaminate the resin. Anionic resins also consume equivalent amounts of sodium hydroxide to remove aromatic acids. Furthermore, this method cannot directly recover cobalt / manganese catalyst for reuse. It is desirable to recover all the washing water components for recycling. [Disclosure of the invention] The present invention is an improved method for purifying aromatic acids. The invention recovers lost aromatic acid products and heavy metal oxidation catalysts and recycles purified water. The method includes the following steps: filtration to recover insoluble aromatic acids, ion exchange to recover and purify heavy metal oxidation catalysts, and a reverse osmosis system to recover water for reuse. Wastewater contains a considerable amount of insoluble aromatic acids. Aromatic acids available

Page 5 1224581 V. Description of the invention (2) Filter device recovery, such as filter. The preferred method is continuous: a tubular filter returning to f or a horizontal cross-flow through the 滹 5 | special and moving filter. Filter the particles containing j in the permeate by the inorganic pregnancy plate. The beginning of the catalyst and manganese. Heart heavy metals are iron oxide, chromium and nickel. Metal containers and / or heavy metals including resins were removed from the container. After the wastewater is regenerated by strong acid cations (SAC), the strong, strong, and strong impurities are generated. Cobalt / manganese-containing catalyst and Caozi ^ fat are washed with water and then returned for reuse. The regenerated organisms that are impurities that are purified by the exchange process are further passed through the cobalt / manganese catalyst recovered by the ion. The catalyst is recovered and recycled to the aromatic acid process. Recovery: (1) Two-step method of tf hunting The metal purified and regenerated from the regeneration solution: Shen 丨 Dian out of the base metal, and then the Shen Dian container containing the right one # is passed through the salt solution to remove the cobalt / manganese catalyst. The next step is to inoculate a special ion exchange resin (IER) which can be used in Sodium ions are present in the media. • Dejunction / catalyst '(3) Regeneration of special IER and recovery of cobalt / manganese catalyst ^ ^ Reverse osmosis system to obtain excellent separation of organic acids and water. The permeate is circulated to the purification process The retentate contains organic salts and is sent to the waste ^ The object of the present invention is to provide the aromatic acid product to be recycled by the washing water produced in the production of aromatic acid. Another object of the invention is to provide an effective metal catalyst recovery. The invention also has-the purpose is to provide effective recovery of washing water.

1224581

These and other objects and advantages of the present invention are described by going to # 你 > 笑 '5 田 号 in the following detailed description of the preferred specific examples. The accompanying drawings will be clearly legible, and the description of the drawings is as follows [Simplified description of the drawings]

Figure 1 is a schematic flow chart of the improved method of the present invention, illustrating method step 7: (1) recovery of insoluble aromatic acids by tritium, (2) recovery and recovery of ion exchange, heavy metal oxidation catalyst, and (3) reverse The infiltration and recovery of water supply is beneficial again. Figure 2 is a detailed flowchart of the wastewater treatment method; Figure 3 is a detailed flowchart of the catalyst recovery method for purifying the recovered cobalt / manganese catalyst in a three-step method: (1) Base metals are precipitated by adjusting the pH, followed by filtration to remove the precipitated metals. (2) The cobalt / catalyst is removed from the saline solution by passing brine through a container containing a special ion exchange resin (IER). It can selectively remove cobalt / manganese catalysts in the presence of sodium ions. (3) Regenerating special ion-exchange resins to recover recording / violent catalysts. [Best Mode for Carrying Out the Invention]

A preferred specific example of the present invention will be described with reference to FIG. The present invention is an improved device and method for purifying aromatic acid washing water produced during the purification of aromatic acid. The invention recovers lost aromatic acid products and heavy metal oxidation catalysts and recycles purified water. As shown in FIG. 1, the waste washing water 2 0 from the aromatic acid purification process (not shown in the drawing) is first filtered in the filtration system 10 to recover the insoluble aromatic acid 2 1, and then the ion exchange recovery process 11 is used to recover and purify the heavy metals. The oxidation catalyst 12 and finally the reverse osmosis system 13 are used to recover the purified water 14 for reuse. The details of the preferred embodiment of this method are not shown in Figs. The waste washing water 2O obtained from the purification process of aromatic acid contains a considerable amount of insoluble aromatic acid 21. Insoluble

Page 7 V. Description of the invention (4) Aromatic acid 21 is a 10-pass filter using a filtering system such as a backwashable tubular filter or: == !! The preferred method as shown in Figure 2 is continuous Cross Flow Filter: Bigger? two. For example, the f-filter 30 preferably uses a membrane made of an inorganic material, and the second action is effective for severe operating temperature conditions and acidity; 4: two temples are fine particles. She gifted Q 7 丄 1 bundle, which is not limited to climbing the soil, and other materials including, but not limited to, the two; including but not limited to the non-"= = cross membrane 31 and cycle to cycle from there f 33 cycles% washing water 21 spans, while solids remain suspended; :: 4: 4 intersections; penetration through the membrane depends on several factors such as particle size, pen gram degrees. The wave length is taken out by the acid rejection stream 35. Out and sent to the thick crying circle :: strong aroma shown), and then circulate to the aromatic acid process Λ: after the ion exchange process is not shown in the following figure, the volume of the permeate is not 3 particles after the filter 36, the permeate is filtered 36 contains low-concentration heavy metals. Cobalt and manganese. In addition to oxidation catalysts, there are also nickel oxides. Metals are removed by passing wastewater through; acid is iron, chromium, and iron 40. Strong acid ionization is preferred ; = „) Resin content polymer. Strong acid cation resins are preferred because they can be separated: two: crosslinked polystyrene cations. The permeate 36 contains gas ions that effectively remove organic acids. Strong acid cations; lipids; will penetrate 1224581 V. Description of the invention (5) '---- The acid-cation resin container 40 may be in the form of hydrogen or sodium before introduction. For economic reasons the preferred form is sodium. Acidic sodium chloride (saline) solution is the preferred regenerant. The salt solution was exchanged for heavy metals with sodium at low pH. It is necessary to prevent the precipitation of heavy metals as metal oxides and contamination of strong acid cation resins. After the SAC resin is regenerated, it is washed with water and then sent to reuse. Another method of regenerating SAC resin is to convert SA (: resin from sodium form to hydrogen form by acid through SA (: resin). Regeneration 41, containing /, manganese catalyst and other heavy metal impurities is further transmitted through ion exchange. The catalyst is purified and recovered by the process for recycling to the manufacturing method. The cobalt / manganese catalyst is purified by a three-step method illustrated in Figure 3 and recovered by the regenerating 41. First, the base metal is adjusted for regenerating by using caustic soda The pH value of 41 is precipitated in the container 50, and then the base metal filter 5 is used to remove the precipitated base metal. The salt solution 52 passes through the base metal filter 51, and the solution contains a cobalt / manganese catalyst. The salt solution 52 passes through the container "to remove the cobalt / manganese catalyst from the solution. The container contains a special ion exchange resin (IER) that can selectively remove the cobalt / manganese catalyst in the presence of sodium ions. Finally, the special ion exchange resin It is regenerated to recover cobalt / manganese catalyst 5 4. A precipitation process is completed by adding a small amount of caustic soda (NaOH) 60 to the regenerate 4 ι to raise the pH value to 4-5. Base metals are precipitated as metal oxides Borrow and borrow It is known that the filtering method is removed in the base metal filter 51. The pH value of the R salt solution 5 2 obtained from the base metal filter 5 2 is raised to 6-7 with sodium hydroxide 61, passed through the bran, and used an ion exchange resin container. 53 to remove cobalt / manganese catalyst. Special type ion exchange resin is commonly known as chelated ion exchange resin or selective ion exchange tree

1224581 V. Description of Invention (6) Month. Selective ion exchange resins suitable for this process contain functional groups such as, but not limited to, aminodiacetic acid, aminophosphonic acid, and polyacrylic acid. The chlorinic acid (HBr) solution 62 is then removed from the selective IER through the ion exchange resin container 53. The resulting recovered catalyst solution 54 contains the catalyst and hydrobromic acid, and now has sufficient concentration and purity to be returned to the aromatic acid process. The pH of the salt solution 63 by selective IER is lowered to approximately with hydrochloric acid 64! 5-3 and reused for recycled SAC resin. Referring to Fig. 2, the Qiu value of the regenerative 41 obtained from the SAC resin container 40 is typically in the range of 1.5-3. The pH was adjusted to 5-7 with sodium hydroxide 65. 2. The salts dissolved in the waste washing water are sodium salts of various organic acids, such as benzoic acid, meta-acid acid, p-arsolic acid and p-toluic acid. Because the waste strip washing water 69 passes the temperature of about 75, the temperature of the cold part of the washing water 69 to about 25-45 t is convenient for reverse osmosis. The reverse osmosis system provides an excellent separation of organic acids and washing water. The permeate 81 of the osmotic self-reverse osmosis system 80 is suitable for recycling to the purification process. Organic salt-containing retentate 8 2 is sent to waste treatment (not shown in the figure [recycling rate of waste washing water containing low concentration of organic acid salt is about 85%. The world produces extremely large amounts of aromatic acids every year. Large Sam weaving fiber and food packaging resin and thin fragrant acid are in the presence of heavy metal oxidation catalysts through octagonal jf methyl form and m-toluene to correspond to aromatic acids. Production of technical grade products in A and A processes is typically not suitable for J = process production Therefore, the impurity is usually a part of oxygen: (Because the pair is Λ

I Page 10 1224581 V. Description of the invention (7) Formic acid, 4-carboxylates are used to raise water-soluble fragrant acid after aromatic hydrogenation, sent to the media and Ruhua Touch. This figure only describes the temperature and temperature of technical grade D A. Liquid and hydrogen products. Fragrant acid is dissolved by impurities and the water in the residual wastewater is damaged. The media and washing have been used to exemplify the present invention, benzaldehyde, etc.) and color products such as 2, 6- "polymer products produced by technical grade aromatic acids and IPA. After further purification to remove impurities, the demineralized water vapor dissolved under extreme pressure is then passed through a container containing a hydrogenation catalyst and then the aqueous solution is cooled, so that the aromatic acid is dissolved in the wastewater by conventional means such as centrifugation or rotary vacuum filtration. This process produces wastewater containing excess amounts of aromatic acids and heavy metal oxidation catalysts, resulting in aromatic acid products and loss. There is a need for a way to efficiently recycle aromatic acids to produce water. The description is illustrated by reference to certain preferred alternatives and is by no means limited to the full scope of the attached application. Dicarboxyfluorenone. Miscellaneous harmful effects. 1 The aromatic acid is removed to remove impurities. Further purification was crystallized from the aromatics. Ran recycling. The remaining unintended miscellaneous. Typical wastewater is oxidized by heavy metals and heavy metal oxygen. These examples are intended to be patented.

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Claims (1)

122 ^ 581 丨 / \ jit- [rJ \ 口 93. 5 · One Replacement _ This Amendment No. 88114525 6. Application Patent Scope 1 · A method for purifying and recycling waste washing water in the purification of aromatic acids, wherein the waste washing water contains insoluble aromatic acids and heavy metal oxides. Medium, other heavy metal impurities, and organic salts, the method includes the following steps: (a) Passing the waste washing water through a continuous cross-flow filter to recover insoluble aromatic acids, wherein the continuous cross-flow filter includes an inorganic membrane, so that The waste washing water is circulated at a sufficient speed while crossing to maintain the surface of the membrane substantially free of insoluble aromatic acid granules, so that the insoluble aromatic acid granules are suspended and concentrated in the cross flow of the waste washing water; (b ) Pass the waste washing water through the continuous cross-flow filter to remove heavy metal oxidation catalysts and other heavy metal impurities through a strong acid cation exchange resin in the form of sodium. (C) The waste washing water removes organic salts through a reverse osmosis system. ; And (d) returning the waste washing water to the aromatic acid purification process; Franciscan cry. 2-A method for purifying and recycling waste washing water in the purification of aromatic acids, wherein the waste washing water contains insoluble aromatic acids, heavy metal oxidation catalysts, other heavy metal impurities and organic salts, and the method includes the following steps: (a) Passing the waste washing > strip of water through a continuous cross-flow filter to recover the insoluble aromatic acid ', where the continuous cross-flow filter contains an inorganic membrane, which allows the waste wash water to circulate at a sufficient rate while crossing to maintain the The surface of the membrane is substantially free of insoluble aromatic acid particles, so that the insoluble aromatic acid particles are suspended and concentrated in the cross-flow flow of the waste washing water; ~ (b) the waste wash water is passed through the continuous cross-flow filter To remove heavy metal oxidation catalysts through a nano-form strong acid cation exchange resin and (:: \ Total file \ 88 \ 88114525 \ 88114525 (Replace) -2.pt Page 13 1224581 1st 88114㊇ 6. Other heavy metal impurities in the scope of the patent application; (c) Waste washing water is passed through (d) the waste washing water to the 4th system to remove organic salts; and the pure washing water is returned to the aromatic acid purification process; Among them, the continuous handing 7 < device. The flow filter is a sintered powder metal alloy filter. 3: The method in the patent claim i or the step of the strong acid cationic resin is included in the third package. The regeneration metal oxidase shrinks and thus produces a regenerative process, which contains heavy metal lice. Catalysts and other heavy metal impurities. Step 4: m: ί :: The method surrounding item 3, which further includes the following steps to exhaustion, so that the value of ρ, ρ, and ρ is equal to precipitation of heavy metal impurities to recover heavy metals. Impurities, the heavy metal oxidation catalyst is selectively removed by regenerating the resin, and the heavy metal oxidation catalyst is recovered by regenerating beauty ion exchange resin. 5. The method according to item 4 of the patent application, wherein the catalyst comprises cobalt and magnesium. Stomach # Chlorine 6: The method of applying for item 5 of the patent, wherein the regenerant is _ C: \ _ t \ 88 \ 88114525 \ 88114525 (replace)-2.ptc page 14