201026613 六、發明說明： C 明所屬々貝3 發明領域 本發明有關一種處理在芳香酸製備過程中所產生之廢 水的方法及有關在廢水中有用組份的回收。 I：先前技術】 發明背景 芳香酸為商業上用於生產塑膠材料之重要化學品。一 特別重要的芳香酸為純化之對苯二曱酸(PTA)，其在近年來 已可見需求的增加’因為其做為生產數種應用之原料，如 塗料、基於不飽和聚酯樹脂之複合材料、熱熔黏合劑的生 產及在聚酯纖維的生產上做為原料。 PTA的工業生產已因聚酯纖維的需求增加而趨動，其 由聚乙烯對苯二曱酸酯生產(PET)。PTA為一用於PET生產 的原料化學化合物。pET用於製造服裝及家飾的織品如床 單、床罩、窗簾及布料。聚酯纖維亦可與天然纖維如棉花 紡織於一起以生產有改良性質的布料，如防皺性。 因此’聚酯工業特別感興趣於製備及純化PTA的製 程。一已知的PTA生產方法涉及在氧化作用催化劑如鈷(Co) 及(Μη)存在下之對二甲苯的氧化作用 以生產ΡΤΑ。接著， ΡΤΑ藉由溶解於一高温水溶液以純化之，接著以一氫化催 化劑處理並接續以冷卻溶液再結晶。此—純化製程產生大 量的廢水’且在此廢水中含有化合物如溶解之有機物質、 重金屬不純物及氧化作用催化劑金屬。亦預期部份ΡΤΑ將 201026613 夾帶於廢水中且此夾帶的pTA的回收為可理解的預期。然 而更重要者為溶解在廢水中的昂貴可再回收之催化劑金 屬的回收。因此，迄今已建議有關由PTA廢水回收PTA、水 及氧化作用催化劑的方法。 在已知的方法中，源自PTA純化製程之PTA廢水流沿路 徑至一濾器以回收不溶pTA。此濾液接著通過一離子交換 樹脂（IER)以吸附住催化劑及任何存在廢水中的金屬不純 物。最後，IER的排出物送至逆滲透(R〇)單元以回收水。 IER使用一強酸為再生劑以再生。含有過量混入金屬及 催化劑金屬之再生劑溶液以驗性溶液如氫氧化鈉及碳酸鈉 (NafO3)處理，且尤其是氫氧化鈉(Na〇H)，以將金屬以氫 氧化物沉澱，其可接著由再生劑溶液分離。再生劑溶液的 pH首先調整至4至5範圍間，藉此部份金屬以氫氧化物沉澱 並以一沉積物移除。加入更多的Na〇H以更增加再生劑溶液 的pH到8.58至9.5。在此pH，大量的催化劑金屬沉澱為氳氧 化物且以沉積物移除。此沉積物可使用框板過濾器移除。 含有沉積物的催化劑使用一適當溶劑再溶解（通常為乙 酸）’且此溶解溶液於催化劑溶液回至pTA氧化作用製程前 通過一 IER以純化之。 此經過IER柱的廢水流進一步進行鹼性添加以增加其 pH到5至7的值，因此維持有機物質的溶解度。此廢水接著 通過一二階段逆滲透單元以移除有機鹽、有機化合物及其 他微量之金屬離子。此回收的水沿路徑回至ρΤΑ生產製程 中以再使用。 201026613 已知方法的缺點在於其需要一驗性溶液(例如Na2c〇3) 的二階段添加。第一鹼性添加為沉澱重金屬不純物而第二 鹼性添加為沉澱催化劑金屬。此沉澱之催化劑金屬接著由 廢水濾、出，以水沖洗，以酸再溶解並在可回收實質純催化 劑前進行更進一步的純化步驟。 因此，此已知方法的缺點為下列方面： (1) 以沉殿移除不純物的方法因為在沉殿中的低選擇性 導致一非理想量的不純物之移除； (2) —二階段鹼性添加方法造成有用的催化劑金屬損 失，如將於後文中詳述； (3) 低選擇性導致回收的催化劑具有夾帶的金屬不純 物，因而面臨低催化劑純度；及 (4) 一二階段鹼性添加方法亦造成使用大量的鹼如 NaOH/aC〇3，其造成方法不經濟。 低選擇性的理由為二部份。第一，重金屬不純物及有 用金屬催化劑的分離可經由一連續pH改變而達成。雖然預 期不欲的金屬不純物在最初pH調整至約4或5間沉澱，應瞭 解此沉澱實質上效率低的，可觀量的金屬不純物仍留在再 生劑溶液中或反之亦然，其中部份的有用催化劑過早沉澱 並與不需要的混雜金屬沉積物一起移除。此因為pH值的精 密控制在大規模工業製程中難以控制。 第二，金屬催化劑意即Co及Μη，在後續加入NaOH以 調整溶液p Η至約9期間以一沉積物沉澱出。此一方法面臨缺 少選擇性’因為移除之沉積物典型含有其他金屬的氫氧化 5 201026613 物，以及Co與Μη者。因此，此催化劑回收步驟中選擇性的 缺乏導致回收之催化劑為低純度量。此在回收之催化劑當 循環回至ΡΤΑ純化製程時特別重要。可能存在於回收之催 化劑流中的重金屬不純物更導致催化劑污濁並減少ρΤΑ生 產的總產量。 在此已知方法的又一缺點為在廢水流通過至R〇單元 前需要加入鹼性。典型地，每一公升的廢水需要加入約1〇〇〇 mg之NaOH以充分改變pH。再者，此導致高操作成本以及 高量NaOH消耗。再者，因為在廢水流中增加Na+離子的量， 因此需要一二階段RO單元以適當的移除金屬離子及有機 鹽/化合物。此更增加資本投資及操作成本。此外，在ρτΑ 生產中對存在於回收水中的Na+離子量有一嚴格的要求。在 一實施例中，存在於回收水中的Na+離子濃度的要求為每公 升少於50毫克，故其可適於循環回至PTA純化製程中。 在另一已知之用於處理PTA廢水的方法，金屬不純物 在第一鹼性添加中沉澱並移除。此廢水接著通過用於吸附 催化劑金屬的螯合樹脂。使用無機酸例如HC1，再生樹脂且 再加入鹼性溶液至再生劑以沉澱並回收催化劑金屬。此已 經過螯合樹脂的廢水流進行鹼性添加以增MpH至約6_7。接 著使用一二階段RO單元以由廢水流中回收水。此方法的缺 點相似於前述者，亦即高度消耗鹼性、需要裝設一二階段 RO單元，因而發生因前述者的高資本投資及操作成本。 因此，需要一種處理在芳香酸製備過程中所產生之廢 水的方法。其可克服或至少改良前述缺點之—或一以上者。 201026613 亦需要一處理PTA廢水的方法，其不需要調整PH至高 度驗性條件。更需要一處理PTA廢水的方法，其消耗較少 的NaOH且不需要二階段逆滲透單元。亦需要一處理PTA廢 水的方法，其自然的高度選擇且造成的改良回收催化劑之 純度。 C發明内容】 發明概要 在第一態樣中，提供一種自芳香酸製備過程所產生之 廢水中移除不溶芳香酸、氧化作用催化劑及金屬不純物的 處理方法，該處理方法包含步驟： (a) 過濾該廢水以回收該不溶芳香酸； (b) 將步驟(a)的濾液通過一離子交換樹脂以選擇性移 除至少一金屬不純物；及 (c) 將步驟(b)的排出物通過能吸附該氧化作用催化劑 的離子交換樹脂。 至少一該金屬不純物為選自包含鉻、鎳及鐵的組群中。 有利地’藉由在步驟⑷前選擇性移除部份金屬不純 物’此移除之金屬不純物將不會吸附至步驟(c)的樹脂上。 此允許在步驟(c)中氧化作用催化劑較佳的吸附於樹脂上。 因此，此回收之氧化作用催化劑實質上無金屬不純物。 在一實施例中，提供一由芳香酸製備過程中所產生之 廢水中移除不溶芳香酸、氧化作用催化劑及金屬不純物的 處理方法，該廢水具有—少於5重量百分比之單親，較佳 為少於1重量百分比之單幾酸，更較佳為少於0.05重量百分 201026613 比之單羧酸，該處理方法包含步驟： (a) 過濾該廢水以回收該不溶芳香酸； (b) 將步驟(a)的濾液通過一離子交換樹脂以選擇性移 除至少一金屬不純物；及 (c) 將步驟(b)的排出物通過能吸附該氧化作用催化劑 的離子交換樹脂。 可選擇地，第一態樣的方法包含步驟： (d) 將步驟(c)的排出物通過一逆滲透系統以移除有機 鹽及有機化合物。 亦可選擇地，第一態樣的方法可更包含步驟：加熱通 過步驟(a)的濾液至約至少50°C至約至少60°C。在一實施例 中，此濾液加熱至60°C温度。 有利地，在步驟(c)及可選擇的步驟(d)間，不需要加入 一驗性溶液至廢水。 有利地，步驟(a)、（b)、（c)及可選擇的步驟(d)分別進行 實質移除該不溶芳香酸、金屬不純物、該氧化作用催化劑 及可選擇的該有機鹽與有機化合物。 在一第二態樣中，提供一種自芳香酸製備過程所產生 之廢水中回收重金屬氧化作用催化劑的方法，該廢水含有 不溶芳香酸、重金屬氧化作用催化劑及金屬不純物，該方 法包含步驟： (e) 過濾該廢水以回收該不溶芳香酸； (f) 將步驟⑷的濾液通過一可選擇性移除選自包含 鉻、鎳及鐵的組群之該金屬不純物的一以上者的離子交換 201026613 樹脂； (g) 將步驟(f)的排出物通過一離子交換樹脂以吸附該 氧化作用催化劑於樹脂上；及 (h) —旦該樹脂由該廢水移除，該樹脂在一水性再生劑 溶液中解吸附。 該方法更包含步驟： ⑴將步驟(g)的排出物通過一逆滲透系統以移除任何 溶解之有機鹽及化合物。有利地，此通過步驟⑴產生工業 級水。 在一第三態樣中，提供一種處理含有芳香酸的廢水之 方法，該方法包含步驟：將廢水在pH少於約5通過一逆滲透 系統。有利地，本發明方法不需要加入一鹼性溶液以改變 廢水的pH。 在一第四態樣中，提供一種自芳香酸製備過程所產生 之廢水中移除不溶芳香酸、重金屬氧化作用催化劑、金屬 不純物的處理方法，該處理方法包含步驟：將廢水通過一 過/慮裳置以移除失帶的固體；將滤液通過一離子交換樹脂 以由其移除金屬並回收氧化作用催化劑；加熱該離子交換 樹脂之排放流到至少6(rc ;並將加熱之排放流通過一逆滲 透單元以因此回收水。 在第四態樣之方法的加熱步驟中，此排放流可加熱至 至少60。(：到至少9〇t溫度。有利地，此加熱步驟允許排放 流維持一飽和態或一稍少之飽和態，因此防止任何不溶之 有機鹽或有機化合物的結晶，此為後續逆滲透步驟中所不 9 201026613 期待的。 定義 本文使用之下列字詞及專有名詞具有下列說明的定義： 本文中使用之“芳香酸”意指一具有一酸基接至芳香環 碳上的化合物。例示之芳香酸為對苯二曱酸或純對苯二甲 酸（PTA)。 本文中使用之“氧化作用催化劑”意指重金屬如鈷金屬 離子及錳金屬離子，其可用於對二甲酸氧化催化至對苯二 甲酸。 本文中使用之“重金屬”意指在工業廢中典型遇到之具 有原子質量數大於24的金屬。例示之重金屬包括砷、鈣、 絡、銅、錯、鎂、汞、銀及鋅。 本文中使用之“有機物質”意指任何含有在芳香酸，如 對苯二甲酸製造期間存在或產生的烴化合物之物質。例示 之有機物質包括在PTA合成期間形成的部份氧化之中間產 物如對苯甲酸及4-羧基苯甲醛等。 本文中使用之“離子交換樹脂”一詞，縮寫為“IER”，其 意指合成聚合物，其包含正價或負價活性位置，其能夠自 周圍溶液中結合至一相反價位離子。 本文中使用之“工業級水”意指實質上無金屬離子及有 機物質的水。 ‘‘實質上”一詞並未排除“全部”，例如一“實質上無”Y的 組成物為可完全無Y。當需要時，“實質上”一詞可由本發明 的界定中省去。 201026613 除非特別指明，“包含(comprising)，，及“包含(c〇mprise)” 與其等文法上的變化詞為欲表達“開放（〇pen)”或“包括 (inclusive)”語意以使其包括列舉的組份且亦允許包括額 未、未列舉的組份。 在本文中於配方之組份濃度中使用“約”一詞典型意指 所指出值的+/-5%，較典型為所指出值的+/_4%，更典型為 所指出值的+/-3%，更加典型為所指出值的+/_2%，最典型 φ 為所指出值的+/-1%，及甚至更最典型為所指出值的 +/-0.5% 〇 在此揭露全文中，在一範圍形式揭露特定的實施例。 應瞭解在範圍形式的描述僅為便利及簡述之用且不應解釋 為本發明揭露範圍之範疇的不可變限制。因此，一範圍的 也述應考慮為具有特定揭露所有可能的次範圍以及在此範 圍内的個別數值。例如，一範圍如丨至6的描述應考慮為具 有特定揭露的次範圍如自1至3、自1至4、自1至5、自2至4、 0 自2至6、自3至6等，以及在該範圍内各獨數值例如卜2、3、 4、5及6。此應用無關於範圍大小。 可選擇之實施例的揭露 現將描述處理PTA廢水及氧化催化劑回收的方法之例 示、非限制的實施例。 在一實施例中’進入過濾步驟⑷的廢水主要為其溶 劑，且可具有少於5重量百分比之單羧酸，較佳為少於1重 量百分比之單羧酸’更較佳為少於〇〇5重量百分比之單羧 11 201026613 酸。在一實施例中，該廢水具有少於〇·〇5重量百分比之單 叛酸。 在第一態樣的過濾步驟中，可使用任何熟於此項技術 人士已泛知的過濾設計。例示的濾器可包括不鏽鋼膜、陶 瓷膜、聚合物膜、板框式過濾器及袋式濾器等 在第一態樣中，在步驟(b)中選擇性移除金屬不純物包 含藉由吸附至離子交換樹脂(IER)移除鎳（Ni)、鉻(Cr)及附隨 的鐵(Fe)。本方法使用的IER可為一能夠吸附Cr、Ni及Fe離 子的弱酸樹脂或螯合樹脂。在一實施例中，在步驟(b)使用 的IER為一弱酸樹脂。一可選擇性由廢水移除金屬不純物如 Ni離子的例示樹脂為弱酸陽離子交換樹脂如美國陶氏化學 公司之DOWEX MAC-3™。201026613 VI. INSTRUCTIONS: C. Affiliated Mussels 3 Field of the Invention The present invention relates to a method for treating waste water produced in the preparation of aromatic acid and to the recovery of useful components in wastewater. I: Prior Art Background of the Invention Aromatic acids are important chemicals commercially used in the production of plastic materials. A particularly important aromatic acid is purified terephthalic acid (PTA), which has seen an increase in demand in recent years' because it is used as a raw material for the production of several applications, such as coatings, composites based on unsaturated polyester resins. Production of materials, hot melt adhesives and as raw materials in the production of polyester fibers. Industrial production of PTA has been driven by increased demand for polyester fibers, which are produced from polyethylene terephthalate (PET). PTA is a raw chemical compound used in PET production. pET is used in the manufacture of clothing and home textiles such as bed sheets, bedspreads, curtains and fabrics. Polyester fibers can also be woven with natural fibers such as cotton to produce fabrics with improved properties such as crease resistance. Therefore, the polyester industry is particularly interested in the process of preparing and purifying PTA. A known PTA production process involves the oxidation of p-xylene in the presence of an oxidation catalyst such as cobalt (Co) and (?) to produce ruthenium. Next, the crucible is purified by dissolving in a high-temperature aqueous solution, followed by treatment with a hydrogenation catalyst and then recrystallizing from the cooling solution. This - the purification process produces a large amount of waste water' and contains therein compounds such as dissolved organic matter, heavy metal impurities and oxidation catalyst metals. It is also expected that some of the plutonium will entrain 201026613 in wastewater and the recovery of this entrained pTA is understandable. However, more important is the recovery of expensive recyclable catalyst metals dissolved in wastewater. Therefore, a method for recovering PTA, water, and an oxidation catalyst from PTA wastewater has been proposed so far. In a known process, a PTA wastewater stream derived from a PTA purification process is passed along a path to a filter to recover insoluble pTA. This filtrate is then passed through an ion exchange resin (IER) to adsorb the catalyst and any metal impurities present in the wastewater. Finally, the ERE effluent is sent to a reverse osmosis (R〇) unit to recover water. The IER uses a strong acid as a regenerant to regenerate. A regenerant solution containing an excessive amount of a metal and a catalyst metal is treated with an inert solution such as sodium hydroxide and sodium carbonate (NafO3), and especially sodium hydroxide (Na〇H) to precipitate the metal as a hydroxide. It is then separated by a regenerant solution. The pH of the regenerant solution is first adjusted to a range of 4 to 5 whereby a portion of the metal is precipitated as hydroxide and removed as a deposit. Add more Na〇H to increase the pH of the regenerant solution to 8.58 to 9.5. At this pH, a large amount of catalyst metal precipitates as a cerium oxide and is removed as a deposit. This deposit can be removed using a frame filter. The catalyst containing the precipitate is redissolved (usually acetic acid) using a suitable solvent and the dissolved solution is purified by an IER before the catalyst solution is returned to the pTA oxidation process. This waste stream passing through the IER column is further subjected to alkaline addition to increase its pH to a value of 5 to 7, thus maintaining the solubility of the organic substance. This waste water is then passed through a two-stage reverse osmosis unit to remove organic salts, organic compounds and other traces of metal ions. This recovered water is returned to the ρΤΑ production process along the path for reuse. A disadvantage of the known method is that it requires a two-stage addition of an assay solution (eg Na2c〇3). The first alkaline addition is precipitation of heavy metal impurities and the second basic addition is precipitation of catalyst metal. The precipitated catalyst metal is then filtered from the waste water, rinsed with water, redissolved with acid and subjected to further purification steps before the substantially pure catalyst can be recovered. Therefore, the disadvantages of this known method are as follows: (1) The method of removing impurities in the sinking hall results in the removal of a non-ideal amount of impurities due to low selectivity in the sinking chamber; (2) - two-stage alkaline The addition method results in a useful catalyst metal loss, as will be detailed later; (3) low selectivity results in recovered catalyst having entrained metal impurities and thus low catalyst purity; and (4) one-two stage alkaline addition method It also causes the use of a large amount of a base such as NaOH/aC〇3, which makes the process uneconomical. The reason for low selectivity is two parts. First, the separation of heavy metal impurities and useful metal catalysts can be achieved by a continuous pH change. Although it is expected that the undesired metal impurities will be adjusted to an initial pH of about 4 or 5, it should be understood that the precipitation is substantially inefficient, and a considerable amount of metal impurities remain in the regenerant solution or vice versa. The useful catalyst precipitates prematurely and is removed along with the unwanted mixed metal deposits. This is because the precise control of pH is difficult to control in large-scale industrial processes. Second, the metal catalysts, Co and Μ, precipitate as a deposit during the subsequent addition of NaOH to adjust the solution p Η to about 9. This approach is faced with a lack of selectivity 'because the removed deposits typically contain hydroxides of other metals 5 201026613, as well as Co and Μη. Therefore, the lack of selectivity in this catalyst recovery step results in a low purity amount of the recovered catalyst. This is especially important when the recovered catalyst is recycled back to the helium purification process. Heavy metal impurities that may be present in the recovered catalyst stream cause fouling of the catalyst and reduce the overall production of ΤΑ. A further disadvantage of the known method herein is the need to add alkali before the passage of the wastewater to the R unit. Typically, about 1 mg of NaOH is added per liter of wastewater to adequately change the pH. Again, this results in high operating costs and high NaOH consumption. Furthermore, since the amount of Na+ ions is increased in the wastewater stream, a two-stage RO unit is required to properly remove the metal ions and organic salts/compounds. This increases capital investment and operating costs. In addition, there is a strict requirement for the amount of Na+ ions present in the recovered water in the production of ρτΑ. In one embodiment, the Na+ ion concentration present in the recovered water is less than 50 mg per liter, so it may be suitable for recycling back to the PTA purification process. In another known method for treating PTA wastewater, metal impurities are precipitated and removed in a first alkaline addition. This waste water is then passed through a chelating resin for adsorbing the catalyst metal. The inorganic resin such as HCl is used to regenerate the resin and an alkaline solution is further added to the regenerant to precipitate and recover the catalyst metal. This chelating resin-containing wastewater stream is subjected to alkaline addition to increase the MpH to about 6-7. A two-stage RO unit is then used to recover water from the wastewater stream. The disadvantage of this method is similar to that described above, that is, it is highly alkaline and requires a two-stage RO unit, resulting in high capital investment and operating costs due to the foregoing. Therefore, there is a need for a method of treating waste water produced during the preparation of aromatic acid. It may overcome or at least ameliorate the aforementioned disadvantages - or more. 201026613 There is also a need for a method of treating PTA wastewater that does not require adjustment of the pH to high test conditions. There is a further need for a process for treating PTA wastewater that consumes less NaOH and does not require a two-stage reverse osmosis unit. There is also a need for a process for treating PTA waste water, which is naturally highly selective and results in improved purity of the recovered catalyst. SUMMARY OF THE INVENTION In a first aspect, a method for removing insoluble aromatic acid, an oxidation catalyst, and a metal impurity from waste water produced by an aromatic acid preparation process is provided, the method comprising the steps of: (a) Filtering the wastewater to recover the insoluble aromatic acid; (b) passing the filtrate of step (a) through an ion exchange resin to selectively remove at least one metal impurity; and (c) passing the effluent of step (b) through adsorption An ion exchange resin of the oxidation catalyst. At least one of the metal impurities is selected from the group consisting of chromium, nickel, and iron. Advantageously, the metal impurities removed by selective removal of a portion of the metal impurities prior to step (4) will not adsorb to the resin of step (c). This allows the oxidation catalyst to be preferably adsorbed onto the resin in step (c). Therefore, the recovered oxidation catalyst is substantially free of metal impurities. In one embodiment, a method for removing insoluble aromatic acid, an oxidation catalyst, and a metal impurity from waste water produced during the preparation of an aromatic acid is provided, the wastewater having less than 5 weight percent of a single parent, preferably Less than 1 weight percent of the monoacid, more preferably less than 0.05 weight percent of 201026613 to the monocarboxylic acid, the treatment comprising the steps of: (a) filtering the wastewater to recover the insoluble aromatic acid; (b) The filtrate of step (a) is passed through an ion exchange resin to selectively remove at least one metal impurity; and (c) the effluent of step (b) is passed through an ion exchange resin capable of adsorbing the oxidation catalyst. Alternatively, the first aspect of the method comprises the steps of: (d) passing the effluent of step (c) through a reverse osmosis system to remove organic salts and organic compounds. Alternatively, the first aspect of the method may further comprise the step of heating the filtrate through step (a) to from about at least 50 ° C to about at least 60 ° C. In one embodiment, the filtrate is heated to a temperature of 60 °C. Advantageously, between step (c) and optional step (d), it is not necessary to add an assay solution to the wastewater. Advantageously, steps (a), (b), (c) and optionally step (d) respectively perform substantial removal of the insoluble aromatic acid, metal impurities, the oxidation catalyst and optionally the organic salt and organic compound . In a second aspect, there is provided a method for recovering a heavy metal oxidation catalyst from wastewater produced by an aromatic acid preparation process, the wastewater comprising an insoluble aromatic acid, a heavy metal oxidation catalyst, and a metal impurity, the method comprising the steps of: (e Filtering the wastewater to recover the insoluble aromatic acid; (f) passing the filtrate of step (4) through an ion exchange 201026613 resin capable of selectively removing more than one of the metal impurities selected from the group consisting of chromium, nickel and iron (g) passing the effluent of step (f) through an ion exchange resin to adsorb the oxidizing catalyst on the resin; and (h) the resin is removed from the wastewater, the resin is in an aqueous regenerant solution Desorption. The method further comprises the steps of: (1) passing the effluent from step (g) through a reverse osmosis system to remove any dissolved organic salts and compounds. Advantageously, this produces industrial grade water by step (1). In a third aspect, a method of treating wastewater containing an aromatic acid is provided, the method comprising the step of passing the wastewater through a reverse osmosis system at a pH of less than about 5. Advantageously, the process of the invention does not require the addition of an alkaline solution to alter the pH of the wastewater. In a fourth aspect, a method for removing insoluble aromatic acid, a heavy metal oxidation catalyst, and a metal impurity from waste water produced by an aromatic acid preparation process is provided, the method comprising the steps of: passing the wastewater through a Disposed to remove the lost solid; pass the filtrate through an ion exchange resin to remove the metal therefrom and recover the oxidation catalyst; heat the discharge of the ion exchange resin to at least 6 (rc; and pass the heated discharge stream A reverse osmosis unit to thereby recover water. In the heating step of the method of the fourth aspect, the effluent stream can be heated to at least 60. (: to a temperature of at least 9 Torr. Advantageously, this heating step allows the discharge stream to maintain a Saturated or a slightly less saturated state, thus preventing the crystallization of any insoluble organic salts or organic compounds, which is expected in the subsequent reverse osmosis step. 9 201026613 The following terms and proper nouns used herein have the following Definition of the description: As used herein, "aromatic acid" means a compound having an acid group attached to an aromatic ring carbon. The exemplified aromatic acid is Benzophthalic acid or pure terephthalic acid (PTA). As used herein, "oxidation catalyst" means heavy metals such as cobalt metal ions and manganese metal ions, which can be used to catalyze the oxidation of dicarboxylic acid to terephthalic acid. "Heavy metal" as used herein means a metal having an atomic mass number greater than 24, which is typically encountered in industrial waste. The exemplified heavy metals include arsenic, calcium, complex, copper, gold, mercury, silver, and zinc. By "organic matter" is meant any substance containing a hydrocarbon compound present or produced during the manufacture of an aromatic acid such as terephthalic acid. Exemplary organic materials include partially oxidized intermediates formed during PTA synthesis such as p-benzoic acid. And 4-carboxybenzaldehyde, etc. The term "ion exchange resin" is used herein, abbreviated as "IER", which means a synthetic polymer comprising a positive or negative valence site capable of binding from a surrounding solution. To the opposite ionic ion. As used herein, "industrial grade water" means water that is substantially free of metal ions and organic matter. The term 'substantially' does not exclude "all." For example, a "substantially free" Y composition may be completely free of Y. The word "substantially" may be omitted from the definition of the invention when needed. 201026613 "Comprising", unless otherwise specified, And "including (c〇mprise)" and its grammatical variations are intended to express "open" or "inclusive" meaning to include the listed components and also allow for the inclusion of no As used herein, the use of "about" a dictionary type in the component concentration of a formulation means +/- 5% of the indicated value, more typically +/_4% of the indicated value, more typically Indicates +/- 3% of the value, more typically +/_2% of the indicated value, most typical φ is +/- 1% of the indicated value, and even more typically +/- 0.5% of the indicated value Specific embodiments are disclosed in a broad form. It should be understood that the description of the scope of the invention is intended to be illustrative and not restrictive. Therefore, a range should also be considered as having a particular disclosure of all possible sub-ranges and individual values within the scope. For example, a description such as 丨 to 6 should be considered as having a specific disclosure sub-range such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, 0 to 2 to 6, from 3 to 6 Etc., and individual values in the range such as Bu, 2, 3, 4, 5, and 6. This app is not about range size. Disclosure of Alternative Embodiments Illustrative, non-limiting examples of methods of treating PTA wastewater and oxidation catalyst recovery will now be described. In one embodiment, the wastewater entering the filtration step (4) is primarily a solvent and may have less than 5 weight percent monocarboxylic acid, preferably less than 1 weight percent monocarboxylic acid 'more preferably less than 〇 〇 5 weight percent of monocarboxylic acid 11 201026613 acid. In one embodiment, the wastewater has less than 5% by weight of monoterpictic acid. In the filtration step of the first aspect, any filtration design well known to those skilled in the art can be used. The exemplified filter may include a stainless steel film, a ceramic film, a polymer film, a plate and frame filter, a bag filter, etc. In the first aspect, the selective removal of the metal impurity in the step (b) comprises adsorption to the ion The exchange resin (IER) removes nickel (Ni), chromium (Cr), and accompanying iron (Fe). The IER used in the method may be a weak acid resin or a chelating resin capable of adsorbing Cr, Ni and Fe ions. In one embodiment, the IER used in step (b) is a weak acid resin. An exemplary resin that selectively removes metal impurities such as Ni ions from wastewater is a weak acid cation exchange resin such as DowEX MAC-3TM from Dow Chemical Company, USA.
Cr、Ni及Fe的吸附性為高度選擇性的，且此步驟有利 地在廢水流中用於濃縮氧化作用催化劑。在一操作實施例 中，一具有最初含量為約0.16 ppm(每百萬份)的廢水流在通 過IER流出後含有少於0.002 ppm的Ni。 用於芳香酸生產的氧化作用催化劑如PTA，其典型為 钻(Co)及/或锰(Μη)。因此，由廢水移除氧化作用催化劑可 包含將廢水通過一弱酸樹脂或一能與Co及Μη金屬離子形 成螫合物的螯合樹脂。在一實施例中，本文使用一IER為一 螯合樹脂。 第一態樣的方法在步驟(C)後可更包含一精煉步驟： (C1)將廢水通過另一IER以更吸附及移除任何殘留的 金屬不純物。在精煉步驟中典型移除之例示金屬不純物包 201026613 括鈣(Ca)及鎂(Mg)。用於精煉步驟(cl)中的IER樹脂為強酸 或螯合樹脂。在一實施例中，步驟(cl)的樹脂為一強酸樹脂。 有利地，藉由弱酸樹脂或螯合樹脂之^、Ni與部份Fe 的先移除允許後續在螯合樹脂中C〇與Μη的移除更具選擇 性及有效性。且有利地，在精煉步驟(C1)中自有用的金屬 催化劑分離夾▼的金屬不純物可經由一創新的ier配置完 成，因而不需要調整廢水的pH。此有利地克服以鹼性經沉 殿作用回收催化劑伴隨的低純度及產率的問題。且有利 地，此避免用大量的驗性溶液。 在樹脂的再生作用中’本發明揭露的方法亦免除為了 移除在再生步驟中沉澱夾帶金屬之目的而安裝多重過濾/ 沉降單元的需要，因此造成實質節省成本。 更有利地，本案發明人已驚訝地發現Ni、（^與以的先 移除可促進Co及Μη的選擇性移除且更具選擇性。在螯合樹 脂上之Co及Μη的高度選擇性吸附作用允許自廢水中回收 一高百分比的氧化作用催化劑金屬。在一實施例中，由螯 合樹脂流出的廢水排放流含有少於〇 〇2 ppm的鈷及猛。 因此一高度選擇性的回收，回收之催化劑與自現有方 法回收之催化劑相較亦具有一相對較高程度的純度，其允 許回收之氧化作用催化劑循環用於pTA生產之再氧化催化 作用。 此螯合樹脂可使用強無機酸如氫氣酸(HC1)、乙酸或氫 溴酸(HBr)再生。含有回收之催化劑及酸的再生劑流可直接 循環回至PTA製備方法中。可選擇地，此再生劑流可通入 13 201026613 至一處理單元以進一步純化並濃縮用以循環的回收之催化 劑。在—實施例中，此再生劑流直接送回至PTA製備方法 中，而不需要後處理。 在—實施例中，列於下表1中的回收之催化劑可符合中 國工業品質指數對於Co-Mn-Br液態複合物催化劑之要求。 表1 1 2 3 4 5 6 7 8 91〇The adsorptivity of Cr, Ni and Fe is highly selective, and this step is advantageously used to concentrate the oxidation catalyst in the wastewater stream. In one embodiment, a wastewater stream having an initial level of about 0.16 ppm (per million) contains less than 0.002 ppm of Ni after efflux through the IER. Oxidation catalysts for aromatic acid production such as PTA are typically drilled (Co) and/or manganese (Mn). Therefore, the catalyst for removing oxidation from the wastewater may comprise passing the wastewater through a weak acid resin or a chelating resin capable of forming a chelate with Co and Μη metal ions. In one embodiment, an IER is used herein as a chelating resin. The first aspect of the process may further comprise a refining step after step (C): (C1) passing the wastewater through another IER to more adsorb and remove any residual metal impurities. An exemplary metal impurity package typically removed in the refining step 201026613 includes calcium (Ca) and magnesium (Mg). The IER resin used in the refining step (cl) is a strong acid or a chelating resin. In one embodiment, the resin of step (cl) is a strong acid resin. Advantageously, the prior removal of the weak acid resin or chelating resin, Ni, and a portion of Fe allows subsequent removal of C〇 and Μ in the chelating resin to be more selective and effective. Advantageously, the metal impurities from the useful metal catalyst separation clamp in the refining step (C1) can be completed via an innovative ier configuration, thus eliminating the need to adjust the pH of the wastewater. This advantageously overcomes the problems associated with low purity and yield associated with the recovery of the catalyst by the action of the alkaline chamber. Advantageously, this avoids the use of large amounts of assay solutions. In the regenerative action of the resin, the method disclosed by the present invention also eliminates the need to install multiple filtration/settling units for the purpose of removing precipitated entrained metal during the regeneration step, thus resulting in substantial cost savings. More advantageously, the inventors have surprisingly discovered that the removal of Ni, and the first removal promotes the selective removal of Co and Μη and is more selective. The high selectivity of Co and Μη on the chelating resin Adsorption allows recovery of a high percentage of oxidation catalyst metal from the wastewater. In one embodiment, the wastewater discharge stream from the chelating resin contains less than ppm2 ppm of cobalt and smolder. Thus a highly selective recovery The recovered catalyst also has a relatively high degree of purity compared to the catalyst recovered from the existing process, which allows the recycled oxidation catalyst to be recycled for the reoxidation catalysis of pTA production. The chelate resin can use a strong mineral acid. Regenerating such as hydrogen acid (HC1), acetic acid or hydrobromic acid (HBr). The regenerant stream containing the recovered catalyst and acid can be recycled directly back to the PTA preparation process. Alternatively, the regenerant stream can be passed to 13 201026613 To a processing unit to further purify and concentrate the recovered catalyst for recycle. In the embodiment, the regenerant stream is sent directly back to the PTA preparation process without the need for a back In the examples, the recovered catalysts listed in Table 1 below meet the requirements of the China Industrial Quality Index for Co-Mn-Br liquid composite catalysts. Table 1 1 2 3 4 5 6 7 8 91〇
(Na+K)/10 參數 外觀 (Co2+)wt % (Mn2+)wt % (Br')wt % -6 (S〇42)/10 (Cu2+)/10 -6 (Ni2+)/l〇- (Fe)/10 -6 需求 均質紫-紅液體 2~5 13-20 <10 <10 <10 <20 <10(Na+K)/10 Parameter Appearance (Co2+) wt % (Mn2+) wt % (Br') wt % -6 (S〇42)/10 (Cu2+)/10 -6 (Ni2+)/l〇- (Fe )/10 -6 demand homogeneous purple-red liquid 2~5 13-20 <10 <10 <10 <20 <10
(Γ)/10 -6 -6 不溶物Wt % <50 <200 <0.02 在精煉步驟(Cl)中自IER柱洗提之廢水典型地含有未 參 由樹脂床移除之不溶有機鹽及化合物。因此，在精煉步驟 (C1)後及在通過步驟(d)前，其中排出物通過逆滲透單元以 移除此些有機鹽與化合物，該方法可更包含步驟： 加熱廢水排出物到至少約60°C的溫度，較佳為至少約 70°C。在一實施例中，加熱步驟為介於約60。(：至約90°C間， 較佳為介於約60°C至約80°C間。排放流的高溫增加其飽和 容積並防止溶解之有機物質的結晶。已知習知技術製程藉 由加入NaOH以防止結晶，其如述及增加廢水中的鈉含量且 14 201026613 為水回收不預期的。本發明揭露的方法未使用NaOH以達此 目的。有利地，此允許本發明方法後續使用一單階段的逆 滲透單元回收水。再者，在回收水中存在的Na離子含量亦 顯著降低並符合工業要求。 用於本發明方法之步驟(d)中的逆滲透膜可為一纖維素 型式膜、一芳香族聚醯胺膜或一具有聚醯胺表面之薄膜複 合物(TFC)型式。 用於本發明方法中的離子交換樹脂可適用多種此技術 領域已知的配置。例示之樹脂配置包括固定床樹脂、移動 床樹脂、脈衝床樹脂及仿擬移動床樹脂。在一實施例中， 使用的樹脂床為移動床樹脂。移動床樹脂允許吸附及解吸 附作用在樹脂床的不同區段同時發生。有利地，此樹脂可 持續再生而無需離線而造成本發明揭露方法之中斷。 圖式簡單說明 附圖為用於說明一揭露之實施例並用以解釋本發明技 術思想。然而，需瞭解圖式僅為說明之目的，而非用於限 制本發明。 第1圖顯示PTA廢水處理的製程流程圖之概略示意圖。 第2圖顯示PTA廢水處理及其催化劑回收步驟的製程 流程圖之詳細示意圖。 圖式之詳細說明 現配合第1圖’其顯示PTA廢水處理的製程流程圖。此 製程包括將廢水12通過一濾器20、一離子交換系統40及一 逆滲透單元60。 15 201026613 任何不溶P TA13藉由濾器以過濾物回收並循環回至 PTA製備過程140。現在實質上無不溶芳香酸的滲透物14通 過離子交換系統40。離子交換柱4〇包含安裝至少二樹脂 床。提供一弱酸樹脂床40a以自滲透物14吸收金屬離子如 Fe、Cr及Ni。一再生劑流28同時通過弱樹脂床40a以洗提吸 附之金屬離子至再生劑流32中。現在實質上無金屬離子的 廢水流排出弱樹脂床40a為排放廢水16。排放廢水16接著通 過螯合樹脂床40b，藉此吸附住催化劑金屬，钴及錳。一再 生劑流34同時通過至螯合樹脂床4〇b以洗提催化劑金屬至 一再生劑流36中。回收之催化劑58可直接回收至ρτΑ生產 製程140以用於進一步的氧化催化反應。 廢水以排放流22排出離子交換系統4〇，其實質上無金 屬及氧化作用催化劑，但含有可觀量的溶解有機鹽及化合 物。提供一逆滲透單元60移除一為滯留流25之溶解的有機 鹽與有機化合物並回收工業級水44。 現參考第2圖，其顯示一用於pta廢水處理及催化劑回 收的詳細方法流程圖10。 典型地，由PTA純化製程產生的pTA廢水為在約 100°C-130°C温度及介於ι·8至約3.5間的pH。PTA廢水流12 先通過一不鏽鋼膜濾器20以回收任何夹帶在廢水中的不溶 PTA13。雖然此處只說明不鏽鋼膜濾膜，應清楚瞭解在此 處使用任何熟於是項技術人士可應用的過濾替代方式取 代。回收之PTA13直接循環回至芳香酸製備過程。遽流 含有微量之金屬不純物如各自的離子形式的Mg、ca、Ni、 16 201026613(Γ)/10 -6 -6 insoluble matter Wt % < 50 < 200 < 0.02 The wastewater eluted from the IER column in the refining step (Cl) typically contains insoluble organic salts which are not removed by the resin bed And compounds. Thus, after the refining step (C1) and before passing through step (d), wherein the effluent passes through the reverse osmosis unit to remove such organic salts and compounds, the method may further comprise the step of: heating the wastewater effluent to at least about 60 The temperature of °C is preferably at least about 70 °C. In one embodiment, the heating step is between about 60. (: to about 90 ° C, preferably between about 60 ° C and about 80 ° C. The high temperature of the discharge stream increases its saturation volume and prevents crystallization of dissolved organic matter. Known techniques are known by NaOH is added to prevent crystallization, which increases the sodium content in the wastewater as described and 14 201026613 is not expected for water recovery. The process disclosed herein does not use NaOH for this purpose. Advantageously, this allows the subsequent use of the method of the invention. The single-stage reverse osmosis unit recovers water. Furthermore, the Na ion content present in the recovered water is also significantly reduced and meets industrial requirements. The reverse osmosis membrane used in step (d) of the method of the present invention may be a cellulose type membrane. An aromatic polyamide film or a film composite (TFC) type having a polyamine surface. The ion exchange resin used in the process of the present invention can be applied to a variety of configurations known in the art. The illustrated resin configuration includes Fixed bed resin, moving bed resin, pulse bed resin and imitation moving bed resin. In one embodiment, the resin bed used is a moving bed resin. The moving bed resin allows adsorption and desorption to be The different sections of the lipid bed occur simultaneously. Advantageously, the resin can be continuously regenerated without the need to be taken offline and the method of the present invention is interrupted. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are intended to illustrate an embodiment of the disclosure and to explain the teachings of the invention However, it is to be understood that the drawings are for illustrative purposes only and are not intended to limit the invention. Figure 1 shows a schematic diagram of a process flow diagram for PTA wastewater treatment. Figure 2 shows PTA wastewater treatment and its catalyst recovery steps. Detailed schematic diagram of the process flow diagram. Detailed description of the drawings is now in conjunction with Figure 1 'showing a process flow diagram for PTA wastewater treatment. The process includes passing wastewater 12 through a filter 20, an ion exchange system 40, and a reverse osmosis unit 60. 15 201026613 Any insoluble P TA13 is recovered as a filter by a filter and recycled back to the PTA preparation process 140. The permeate 14 which is substantially free of insoluble aromatic acids now passes through the ion exchange system 40. The ion exchange column 4 contains at least two resins. A weak acid resin bed 40a is provided to absorb metal ions such as Fe, Cr and Ni from the permeate 14. A regenerant stream 28 is simultaneously passed. The resin bed 40a elutes the adsorbed metal ions into the regenerant stream 32. The substantially metal ion free wastewater stream is now discharged from the weak resin bed 40a into the discharged wastewater 16. The discharged wastewater 16 is then passed through a chelate resin bed 40b for adsorption. The catalyst metal, cobalt and manganese are present. A regenerant stream 34 is simultaneously passed to the chelating resin bed 4〇b to elute the catalyst metal to a regenerant stream 36. The recovered catalyst 58 can be directly recovered to the ρτΑ production process 140 for use. For further oxidation catalytic reaction, the wastewater is discharged to the ion exchange system 4 in a discharge stream 22, which is substantially free of metal and oxidation catalysts, but contains appreciable amounts of dissolved organic salts and compounds. A reverse osmosis unit 60 is provided to remove The dissolved organic salt of the stream 25 is retained with the organic compound and the industrial grade water 44 is recovered. Referring now to Figure 2, there is shown a flow chart 10 of a detailed method for pta wastewater treatment and catalyst recovery. Typically, the pTA wastewater produced by the PTA purification process is at a temperature between about 100 ° C and 130 ° C and a pH between 10 and about 3.5. The PTA wastewater stream 12 is first passed through a stainless steel membrane filter 20 to recover any insoluble PTA13 entrained in the wastewater. Although only stainless steel membranes are described here, it should be clearly understood that any alternative filtration method available to those skilled in the art can be used here. The recovered PTA13 is recycled directly back to the aromatic acid preparation process. Turbulence Contains trace amounts of metal impurities such as Mg, ca, Ni, 16 in their respective ionic forms 201026613
Fe及Cr及氧化作用催化劑Co及Μη，其亦為離子形式。為了 調節廢水且同時回收有用的催化劑，濾液14經由熱交換器 11進行加熱以在其通過一離子交換樹脂(IER)系統40前增 加約10至20°C。IER系統40包含一弱酸樹脂床40a、一螯合 樹脂床40b及一強酸樹脂床40c。此些樹脂床的每一者可適 用為固定床、模擬移動床或移動床配置。在本發明之一較 佳實施例中，樹脂床為一移動床設計。 腐蝕金屬不純物如Ni、Cr及Fe為選擇性吸附至弱酸樹 脂床40a上。接著排出的排放流16實質上無Ni、Cr及Fe。一 旦樹脂容積充分耗盡，再生劑28導入至弱酸樹脂床40a中以 由弱酸樹脂床40a洗提吸附之陽離子，Ni、Cr及Fe，在製程 中再生樹脂床40a。本文使用的再生劑28為4-8%氫氣酸 (HC1)。含有HC1再生劑及洗提金屬Ni、Cr及Fe的再生劑流 32排放至一廢水處理單元70以再處理並排放。 有利地，金屬不純物如Ni自有用的氧化作用催化劑分 離並不需要加入大量的昂貴驗如NaOH。亦有利地，因在第 一樹脂床中金屬不純物的選擇性移除為一高度選擇性製 程，其實質上自廢水中移除幾乎全部的腐蝕性金屬不純 物。更重要的’在此步驟中使用的弱酸樹脂不會吸附有用 的Co及Μη離子，藉此在自樹脂床4〇a排放的排放流中濃縮 催化劑金屬。此有助於後續的催化劑回收。 在移動床配置中’ 一部份的弱酸樹脂床40a在一分離部 份持續吸附腐蝕性金屬離子時，其恒定的再生。有利地， 吸附及解吸附製程同時發生且需要將樹脂床系統40離線以 17 201026613 進行樹脂再生。此依次減少整個製程的中斷並改良離子交 換的有效性。 排放流16接著通過螯合樹脂床40b。此步驟允許由廢水 中選擇性的移除氧化作用催化劑金屬，Co及Μη。膨脹的樹 脂以4%HC1流34再生，藉此形成一含有再生劑34與氧化作 用催化劑Co及Μη的再生劑流36。此再生劑流36接著直接循 環回至ΡΤΑ製備過程80。現在實質上不含金屬不純物Ni、Cr 及Fe與催化劑金屬Co及Μη的廢水以排放流18排出螯合樹脂 床40b。存在母液中的殘餘金屬包括金屬如Ca、Mg及Na。 排放流18接著通過一強酸樹脂床40c以捕捉所有的存 在廢水中的殘餘金屬。此膨脹的強酸樹脂40c以一4-8%HCl 流38再生且洗滌流42相似的排放至廢水處理單元90以進一 步處理及丟棄。由強酸樹脂床40c排出的排放流22實質上無 金屬不純物及氧化作用催化劑。為了處理水以可達到適宜 工業使用，進行更進一步的處理步驟以移除任何可能仍存 在於排放流22中的溶解的有機不純物。此處使用一逆滲透 (RO)膜單元60以溶解之有機鹽及化合物。為了保持廢水低 於飽和態’因此預防任何有機物質的結晶，否則會傷害逆 滲透製程’在樹脂柱40及RO單元60間裝設一熱交換器5〇。 典型地’排放流22加熱至6(TC至90°C的溫度以增加母液的 飽和點。 有利地，藉由增加排放流22的温度，廢水的飽和量增 加，因此預防有機鹽及化合物結晶。傳統上，加入Na〇H至 廢水中以壓抑此一結晶。此方法牽涉顯著的成本缺點，因 201026613 為NaOH的成本佔總操作成本的大量比例。藉由避免鹼性的 添加，本發明方法誇耀相當的經濟優點。 加熱之流24經RO膜60過濾，其由廢水中分離大量的有 機鹽及化合物，形成實質上無有機鹽的工業級水。此含有 移除之有機物質的滯留流25沿路徑至一廢水處理單元（未 顯示）。微量的有機不純物在經由r〇膜60過濾後可能仍存 在。在R0單元後提供樹脂床100藉由移除任何微量有機物 質以進一步“精煉”R0濾液。因此形成的水流44為足夠的高 純度且適宜工業應用。此回收水44亦可直接循環回至用於 PTA製備製程。 應用 本發明方法可用於自PTA製備過程產生的廢水中回收 有用的氧化作用催化劑，而不需加入使用大量的昂貴 NaOH。本發明方法在第一選擇性mR中自大量的金屬中選 擇性的分離Ni、Cr及Fe。有利地，此允許氧化作用催化劑 在一母液中濃縮且亦減少金屬不純物結合至一設計用於c〇 及Μη移除之第二IER的可能性。 本發明方法亦可使用選擇性IER以自金屬不純物分離 有用的金屬催化劑。有利地，本發明方法相對於經不同pH 沉澱的分離作用可產生一較高純度的催化劑回收。因此， 本發明方法可回收實質上所有夾帶的在PTA廢水中的催化 劑金屬。回收催化劑亦符合在表丨中說明的工業標準。有利 地’回收之催化劑適於直接循環回至pTA製備過程。 排出IER柱之排放流的温度在逆滲透單元進入前預熱 19 201026613 ^ C至約9〇c。較兩的温度有利地增加排出廢水的冑 和容積並避免任何不溶的有機物質結晶，此結晶將阻障滲 透作用。因為未使用NaOH壓抑有機物f的結晶作用，廢水 中的鈉含量保持低量。因此，本發明之方法亦可使用單— 階段之逆滲透單元自PTA廢水中回收水，而未使用一雙階 段之RO單元。再者，此亦提供製程對Na〇H總量需求的降 低，且再次造成實質節省成本。 可顯見，熟於是項技術人士在閱讀前述揭露後，在未 偏離本發明技術思想及範疇下可顯見本發明之多種其他潤 〇 飾及變化，且欲將此些潤飾及變化亦涵括於後附申請專利 範圍中。 【圖式簡單說明3 第1圖顯示PTA廢水處理的製程流程圖之概略示意圖。 第2圖顯示PTA廢水處理及其催化劑回收步驟的製程 流程圖之詳細示意圖。 【主要元件符號說明】 10…方法流程圖 22…排放流 11…熱交換器 24…流 12…PTA廢水流 25…滞留流 13…不溶PTA 28…再生劑 14…滤流 32···再生劑流 16…排放流 34…再生劑 18…排放流 36…再生劑流 20…濾器 38…流 20 201026613 40…離子交換系統 40a…弱酸樹脂床 40b…螯合樹脂床 40c…強酸樹脂床 42…洗蘇流 44…水 50…熱交換器 58…回收之催化劑 60…逆滲透單元 70…廢水處理單元 80…PTA製備過程 90…廢水處理單元 100…樹脂床 140...PTA製備過程Fe and Cr and oxidation catalysts Co and Μη, which are also in ionic form. In order to adjust the wastewater and simultaneously recover the useful catalyst, the filtrate 14 is heated via the heat exchanger 11 to increase it by about 10 to 20 °C before it passes through an ion exchange resin (IER) system 40. The IER system 40 comprises a weak acid resin bed 40a, a chelate resin bed 40b and a strong acid resin bed 40c. Each of these resin beds can be adapted to be a fixed bed, simulated moving bed or moving bed configuration. In a preferred embodiment of the invention, the resin bed is a moving bed design. Corrosive metal impurities such as Ni, Cr and Fe are selectively adsorbed onto the weak acid resin bed 40a. The discharged discharge stream 16 is then substantially free of Ni, Cr and Fe. Once the resin volume is sufficiently depleted, the regenerant 28 is introduced into the weak acid resin bed 40a to elute the adsorbed cations, Ni, Cr and Fe from the weak acid resin bed 40a, and the resin bed 40a is regenerated in the process. Regenerant 28 as used herein is 4-8% hydrogen acid (HC1). The regenerant stream 32 containing the HC1 regenerant and the eluting metals Ni, Cr and Fe is discharged to a wastewater treatment unit 70 for reprocessing and discharge. Advantageously, metal impurities such as Ni are separated from the useful oxidation catalyst and do not require the addition of a large amount of expensive reagents such as NaOH. Advantageously, the selective removal of metal impurities in the first resin bed is a highly selective process that substantially removes substantially all of the corrosive metal impurities from the wastewater. More importantly, the weak acid resin used in this step does not adsorb useful Co and Μη ions, thereby concentrating the catalyst metal in the discharge stream discharged from the resin bed 4〇a. This facilitates subsequent catalyst recovery. In the moving bed configuration, a portion of the weak acid resin bed 40a is constantly regenerated when a separate portion continues to adsorb corrosive metal ions. Advantageously, the adsorption and desorption processes occur simultaneously and the resin bed system 40 needs to be taken offline to perform resin regeneration at 17 201026613. This in turn reduces interruptions throughout the process and improves the effectiveness of ion exchange. The effluent stream 16 is then passed through a chelating resin bed 40b. This step allows selective removal of the oxidation catalyst metal, Co and 由 from the wastewater. The expanded resin is regenerated in a 4% HC1 stream 34, thereby forming a regenerant stream 36 containing a regenerant 34 and an oxidation catalyst Co and Μη. This regenerant stream 36 is then recycled directly back to the crucible preparation process 80. The wastewater which is substantially free of metallic impurities Ni, Cr and Fe and the catalyst metals Co and Μ is now discharged into the chelating resin bed 40b in a discharge stream 18. Residual metals present in the mother liquor include metals such as Ca, Mg, and Na. The effluent stream 18 is then passed through a bed of strong acid resin 40c to capture all of the residual metals present in the wastewater. The expanded strong acid resin 40c is regenerated with a 4-8% HCl stream 38 and the scrubbing stream 42 is similarly discharged to the wastewater treatment unit 90 for further processing and disposal. The discharge stream 22 discharged from the strong acid resin bed 40c is substantially free of metal impurities and oxidation catalyst. In order to treat the water to achieve suitable industrial use, further processing steps are performed to remove any dissolved organic impurities that may still be present in the effluent stream 22. A reverse osmosis (RO) membrane unit 60 is used herein to dissolve the organic salts and compounds. In order to keep the waste water below the saturation state, the crystallization of any organic matter is prevented, which would otherwise damage the reverse osmosis process. A heat exchanger 5 is placed between the resin column 40 and the RO unit 60. The 'discharge stream 22 is typically heated to 6 (TC to 90 ° C to increase the saturation point of the mother liquor. Advantageously, by increasing the temperature of the effluent stream 22, the amount of saturation of the wastewater increases, thus preventing crystallization of the organic salts and compounds. Traditionally, Na〇H has been added to the wastewater to suppress this crystallization. This method involves significant cost disadvantages, since 201026613 is a large proportion of the cost of NaOH to the total operating cost. By avoiding the addition of alkali, the method of the present invention boast A considerable economic advantage. The heating stream 24 is filtered through the RO membrane 60, which separates a large amount of organic salts and compounds from the wastewater to form an industrial grade water substantially free of organic salts. The retained stream 25 containing the removed organic matter The path to a wastewater treatment unit (not shown). Traces of organic impurities may still be present after filtration through the r diaphragm 60. The resin bed 100 is provided after the R0 unit to further "refining" the R0 filtrate by removing any traces of organic matter. The resulting water stream 44 is of sufficient high purity and suitable for industrial applications. This recovered water 44 can also be recycled directly back to the PTA preparation process. The process can be used to recover useful oxidation catalysts from wastewater produced by the PTA preparation process without the need to add large amounts of expensive NaOH. The process of the present invention selectively separates Ni, Cr from a large number of metals in a first selective mR. And Fe. Advantageously, this allows the oxidation catalyst to be concentrated in a mother liquor and also reduces the possibility of metal impurities binding to a second IER designed for c〇 and 移除 removal. The method of the invention may also use a selective IER Separating useful metal catalysts from metal impurities. Advantageously, the separation of the present invention relative to precipitation by different pH produces a higher purity catalyst recovery. Thus, the process of the invention recovers substantially all entrained PTA wastewater. Catalyst metal. The recovered catalyst also meets the industry standards stated in the table. Advantageously, the recovered catalyst is suitable for direct recycle back to the pTA preparation process. The temperature of the effluent stream exiting the IER column is preheated prior to the entry of the reverse osmosis unit. 19 201026613 ^ C to about 9〇c. Temperatures above two advantageously increase the enthalpy and volume of the discharged wastewater and avoid any insolubility The organic matter crystallizes, and the crystallization will block the osmosis. Since the crystallization of the organic substance f is not suppressed by using NaOH, the sodium content in the wastewater is kept low. Therefore, the method of the present invention can also use a single-stage reverse osmosis unit. The water is recovered in the PTA wastewater without using a two-stage RO unit. In addition, this also provides a reduction in the total demand for Na〇H, and again causes substantial cost savings. It is obvious that the skilled person is reading. The various other stencils and variations of the present invention are apparent from the scope of the present invention, and such modifications and variations are intended to be included in the scope of the appended claims. Note 3 Figure 1 shows a schematic diagram of the process flow diagram for PTA wastewater treatment. Figure 2 shows a detailed schematic of the process flow diagram for PTA wastewater treatment and its catalyst recovery steps. [Description of main component symbols] 10... Method flow chart 22... Emission flow 11... Heat exchanger 24... Flow 12... PTA Waste water flow 25... Retention flow 13... Insoluble PTA 28... Regenerant 14... Filtration 32··· Regenerant Flow 16...discharge stream 34...regenerant 18...discharge stream 36...regenerant stream 20...filter 38...flow 20 201026613 40...ion exchange system 40a...weak acid resin bed 40b...chelating resin bed 40c...strong acid resin bed 42...washing Su stream 44...water 50...heat exchanger 58...recovered catalyst 60...reverse osmosis unit 70...waste treatment unit 80...PTA preparation process 90...waste treatment unit 100...resin bed 140...PTA preparation process
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