TW200838848A - Process for separating acrylic acid and benzoic acid present in a product gas mixture of a partial heterogeneously catalyzed gas phase oxidation of A C3 precursor compound of acrylic acid - Google Patents
Process for separating acrylic acid and benzoic acid present in a product gas mixture of a partial heterogeneously catalyzed gas phase oxidation of A C3 precursor compound of acrylic acid Download PDFInfo
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- TW200838848A TW200838848A TW096139047A TW96139047A TW200838848A TW 200838848 A TW200838848 A TW 200838848A TW 096139047 A TW096139047 A TW 096139047A TW 96139047 A TW96139047 A TW 96139047A TW 200838848 A TW200838848 A TW 200838848A
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- acrylic acid
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- benzoic acid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/23—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups
- C07C51/235—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of oxygen-containing groups to carboxyl groups of —CHO groups or primary alcohol groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
- C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C57/00—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms
- C07C57/02—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms with only carbon-to-carbon double bonds as unsaturation
- C07C57/03—Monocarboxylic acids
- C07C57/04—Acrylic acid; Methacrylic acid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C63/00—Compounds having carboxyl groups bound to a carbon atoms of six-membered aromatic rings
- C07C63/04—Monocyclic monocarboxylic acids
- C07C63/06—Benzoic acid
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Polymerisation Methods In General (AREA)
Abstract
Description
200838848 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種在丙烯酸之c3前驅物化合物的部份非 均相催化氣相氧化反應之產物氣體混合物中分離作為主產 物及副產物之丙烯酸及苯甲酸以及其他產物氣體混合物成 ^ 份之方法，其中將丙烯酸及苯甲酸與沸點比丙浠酸低及高 " 之產物氣體混合物的其他成份一起自產物氣體混合物轉化 為液相p，且使用至少一種熱分離方法自所得液相p移除沸 _ 點低於苯甲酸及丙烯酸之成份，留下包含至少so重量。/〇之 丙烯酸及占丙烯酸含量至少ο·1重量％〇之苯曱酸的液相p*。 【先前技術】 丙烯酸為一種重要單體’其本身及/或其烧酯形式可用 於製得衛生用品領域中所用之聚合物（例如，超吸水聚合 物）（參看，例如，WO 02/055469及 WO 03/078378)。 丙稀酸可（例如）藉由C3前驅物化合物（丙稀、丙烧及/或 丙烯醛)之非均相催化部份氧化反應製備（參看，例如，EP-A 鲁 990636、US-A 5 198578、EP-A 1015410、EP-A 1484303、 EP-A 1484308、EP-A 1484309及 US-A 2004/0242826) 〇 • 就應用觀點而言，所使用之C3前驅物化合物一般為具有 、 相當高純度之C3前驅物化合物（參看，DE-A 10131297)。 然而，獲得（例如）具有該純度之丙烯粗產物相當不容易且 費用高，且該情形一般涉及各種純化階段，以便分離高純 度的丙烯酸之C3前驅物化合物（參看，DE-A 352〗458)。根 據DE_A 12246119及DE-A 10245585，該製程應特別使得用 125528.doc 200838848 於部份氧化反應之所得反應氣體混合物儘可能不包含c 烴，後者係會削弱催化劑效能而不希望其存在之雜質。該 製程之缺點為上述純化階段複雜，因此有時候基於q前驅 物化合物粗產物（例如，粗丙烯粗產）之經濟因素，僅採用 相當有限之分離動作。200838848 IX. Description of the Invention: [Technical Field] The present invention relates to the separation of acrylic acid as a main product and a by-product in a product gas mixture of a partially heterogeneously catalyzed gas phase oxidation reaction of a c3 precursor compound of acrylic acid. And a method of forming a mixture of benzoic acid and other product gases, wherein the acrylic acid and benzoic acid are converted from the product gas mixture to the liquid phase p together with other components of the product gas mixture having a boiling point lower and higher than that of the propionate; The boiling point is removed from the resulting liquid phase p using at least one thermal separation method to a fraction below the benzoic acid and acrylic acid, leaving at least the so weight. / 〇 丙烯酸 丙烯酸 丙烯酸 丙烯酸 及 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸 丙烯酸[Prior Art] Acrylic acid is an important monomer' itself and/or its burnt ester form can be used to produce polymers (for example, superabsorbent polymers) used in the field of sanitary products (see, for example, WO 02/055469 and WO 03/078378). Acrylic acid can be prepared, for example, by heterogeneously catalyzed partial oxidation of a C3 precursor compound (propylene, propyl, and/or acrolein) (see, for example, EP-A Lu 990636, US-A 5 198578, EP-A 1015410, EP-A 1 484 303, EP-A 1 484 308, EP-A 1 484 309 and US-A 2004/0242826) 就 • From the application point of view, the C3 precursor compound used is generally of a relatively high C3 precursor compound of purity (see, DE-A 10131297). However, obtaining, for example, a crude propylene product of this purity is relatively difficult and costly, and this situation generally involves various stages of purification in order to separate high purity acrylic C3 precursor compounds (see, DE-A 352 458). . According to DE_A 12 246 119 and DE-A 10 245 585, the process should in particular be such that the resulting reaction gas mixture of the partial oxidation reaction of 125528.doc 200838848 contains as little as possible c hydrocarbons which impair the catalyst performance without the presence of impurities. The disadvantage of this process is that the above purification stage is complicated, so sometimes only a relatively limited separation action is employed based on the economic factors of the crude product of the q precursor compound (for example, crude propylene).
全面之内部研究現已顯示當用於q前驅物化合物（例 如，丙烯）之非均相催化部份氧化反應的I前驅物化合物 粗產物（例如，丙烯）還包含丁二烯或在部份氧化反應過程 中可轉化為丁二稀之化合物時’ $曱酸可能《為丙烯酸形 成法之副產物。可促成苯甲酸形成之原因大概為丁二烯與 存在於非均相催化部份氧化反應之反應氣體混合物中的C3 親二烯物（諸如丙烯、丙烯醛及丙烯酸）之迪爾-阿德（Diels_ Alder)反應，其很可能由加合物繼續進行非均相催化氧化 脫氫反應，形成芳族化合物。後者大概由與真正目標氣相 氧化反應相同的催化劑催化。若適當，含有鄰二甲苯之q 前驅物化合物粗產物（例如，丙烯粗產物）的輕微污染亦可 為形成苯甲酸副產物之原因。使用具有較高活性之多金屬 氧化物催化劑（或體積·比活性在反應物轉化率增加之方向 增加至少一次的催化劍 d裒枓）另外使用蒸汽作為惰性稀 釋氣體之，且相對於縣定条/卜g 俏对於特疋虱化反應步驟（例如，丙烯—丙 料Ϊ中部份氧化之Μ合物過量之分子態氧似乎促進苯 甲W產物形成’在特定氧化反應階段中之特定c3前驅物 !合物(例如’丙稀形成丙烯酸之兩段式部份氧化反應的 弟1化反應階段中之丙烯，或丙埽形成丙烯酸之部份氧 125528.doc 200838848 化反應的第二氡化反應階段中之丙烯醛，或在丙烯醛形成 丙烯酸之獨立部份氧化反應中的丙烯醛，或丙烷形成丙歸 酸之一段式部份氧化反應中的丙烷）的反應溫度及轉化率 提高亦似乎促進苯甲酸副產物形成。支持上述假設之事實 . 在於許多狀況下發現僅苯甲醛而非苯甲酸作為丙烯酸形成 之副產物。相反地，苯甲酸一般伴有苯甲醛作為丙烯酸副 、 產物。 田 籲 本甲酸與笨甲酸均為不希望有的丙烯酸伴隨物。不希望 的原因在於其為並非完全無害，反而具有相當反應性之芳 知化合物（此點相應地適用於苯甲酸之酯）。因此當使用獲 付之丙烯酸及/或其烷酯來製備可用於衛生領域之聚合物 (例如，尿布中之吸水聚合物）時，必須確保所使用之丙烯 酸及/或所使用之丙烯酸烷酯完全不含苯甲酸及苯甲醛。 眾所周知丙烯酸可藉由不同分離方法之組合自丙烯酸之 c3前驅物化合物（例如，丙稀）之非均相催化部份氣相氧化 • 反應的產物氣體混合物移除。在特定狀況下所採用之組合 -般視在產物氣體混合物中非丙烯酸的次要組份之類型及 夏而定，且視一般由丙烯酸之特定用途指定的丙烯酸之所 ' 要純度而定。 * 該等不同分離方法組合的主要成份通常由熱分離方法形 成。該等熱分離方法為在包含分離内填物的分離柱中由氣 體(上升)及液體(下降)流依逆流形式引導，因料物流之 間存在梯度而發生熱及質量轉移且最終致使分離柱中發生 所要分離。 I25528.doc 200838848 該等熱分離方法之實例為（部份）冷凝、分段冷凝（參看 Μ-A密245 32)及精館。所得分離作用此處特別基於丙稀 酸及非丙烯酸之次要組份的沸點差異。另一實例為吸收 法。此分離作用特別基於丙烯酸及非丙烯酸之次要組份在 液中的不同溶解性。以上所述亦適詩汽提法（汽提 氣體自液體吸收具有不同親和力而以溶解形式存在之組 份）及解吸（吸收之逆過程；藉由降低分壓來移除溶解於液 相中之物質）之熱分離方法。術語，，熱分離方法"亦包含共沸 蒸餾及精餾（其利用丙烯酸及次要組份（部份氧化反應之反 應氣體混合物中非丙烯酸之成份）與添加之共沸劑形成共 沸物之不同趨勢）。 丙烯酸沸點（14TC，在i大氣壓下）與苯甲醛沸點 (178.rC，在1大氣壓下）之間的差異一般不足以使用上述 熱分離方法自具有適當複雜度之丙烯酸中大量移除苯甲 醛。而後者通常僅在另外利用苯甲醛及丙烯酸與所謂的醛 • 淨化劑（W〇 〇3/014172)(例如，胺基胍碳酸氫鹽）之不同反 應性時移除。醛與醛淨化劑之反應形成一種新次要組份， 其沸點偏離丙烯酸沸點之程度大於醛本身偏離丙烯酸沸點 • 之程度，故在與醛淨化劑之反應完成後，可藉由精餾途徑 • 以簡單方式大量移除。或者，EP-A 1159249揭示藉由將熱 分離方法（分段冷凝）與結晶（懸浮結晶）組合來分離在部份 氧化反應之產物氣體混合物中之苯甲趁及丙烯酸（亦參看 DE-A 10247240) 〇 與以上所述相對比，丙烯酸沸點（141 °C，在1大氣壓下） 125528.doc 200838848 與苯甲酸沸點（250°C，在1大氣壓下）之間的差異相♦大 以致於當採用基於混合物成份之不同沸點的熱分離方法、 行分離時，通常可大量分離丙烯酸與苯甲酸（參看，= 10336386 . DE-A 19740252 ^ DE-A 10247240)(^^^^^ 份常在苯曱酸移除後藉由結晶移除）。然而，該熱分離= 一缺點為包含呈富集形式之丙烯酸的餾份必須自加至分= 柱中待分離之混合物饋料上方的包含分離内填物的分=柱 中抽出。然而，此時極需要供應熱源，原因在於丙烯酸之 完全瘵發非常消耗能量（高沸點、高蒸發焓、因回流而需 多次蒸發）。 ❿ 【發明内容】 因此，本發明之一目標在於提供一種在丙烯酸之q前驅 物化合物的部份非均相催化氣相氧化反應之產物氣體混合 物中分離呈主產物及副產物存在的丙烯酸及苯甲酸之方 法’其不需要上述大量消耗能源之分離方法。 因此，提供一種在丙烯酸之q前驅物化合物的部份非均 相催化氣相氧化反應之產物氣體混合物中中分離作為主產 物及副產物之丙烯酸及苯甲酸以及其他產物氣體混合物成 份，其中將丙烯酸及苯甲酸，與沸點比丙烯酸低及高之產 物氣體混合物之其他成份一起自產物氣體混合物轉化為液 相P，且使用至少一種熱分離方法自所得液相p移除沸點比 苯甲酸及丙烯酸低（基於純物質在1大氣壓下之沸點）的成份 (但不含有苯甲酸；”不含有”此處意謂分別占液相p中之苯 甲酸含量之10重量％以下，較佳為5重量％以下，甚至更佳 125528.doc •10- 200838848 為3重量％以下或2重量％以下或1重量％以下，且最佳為 〇·75重里A以下，或〇.1重量％以下’或0重量％)，留下包 含至少80重量％丙烯酸及占丙烯酸含量至少0.1重量％。（經 系至少0·2重量％。，或至少〇·3重量％。，或至少〇·4重量， 或至少0.5重量％。，或至少〇·75重量％。，或至少1重量之 苯甲酸的液相P*，該方法包括使丙烯酸自液相p*中結晶析 出而與苯甲酸分離，丙烯酸積聚在形成之晶體中，苯甲酸 則在殘留之母液中。 【實施方式】 根據本發明之方法係基於與結晶相關之損耗係數 A (以5亥方法為基準）有規律地大於或等於15的驚人發 現。咸了解，損耗係數abza 一般意謂殘留在母液中之苯甲 酸與殘留在晶體中之苯甲酸的含量比（在各狀況下以占母 液總量或晶體總量的重量％表示）。通常晶體/母液移除量 占其總量計90重量％以上的程度，且較佳達％重量％以 上，或97重量％或98重量％或99重量％的程度時，方足以 測定ABZA(殘餘水分含量對晶體的影響_般可忽、略）。大於 或等於15之心表示在丙烯酸晶體之形成中基本上沒有苯 甲酸進入晶體中。此點即形成本發明製程顯著效率的基 礎。 :丙烯酸次要組份為二丙烯酸(aDA)、乙酸(aAA)及丙酸 (APA)時，相應損耗係數通常為小於或等於1〇之數值。換言 之，其亦進入丙烯酸晶體中，作僅 1一惶可（例如）猎由適當洗滌 困難地自該等晶體萃取出。 125528.doc -11- 200838848 換言之，利用結晶法自丙烯酸中移除該等雜質時一般需 要使用效率較低且耗費較高成本之多段式結晶方法，如 (例如）在EP-A 616998中所建議之動態及靜態結晶之多段式 組合形式，且其中亦需要多段式方法、至少一個動態結晶 . 器及至少一個靜態結晶器。最佳地，在結晶之特殊限制條 件（特別參看WO 03/078378及WO 〇1/77056)下，形成丙烯 酸晶體，隨後用純丙烯酸熔體洗滌，相當有效地移除該等 _ 晶體中之乙酸及丙酸來。ABZA愈大，以結晶法移除丙烯酸 結晶中之苯甲酸之方法愈有吸引力。 鑒於上述實驗發現，本發明製程可用在形成適於超吸收 劑之丙烯酸的途徑上，其在結晶階段後用預先純化之丙烯 酸熔體洗滌晶體，基本上可大量移除液相p*中妨礙該用途 之苯甲酸雜質。 在遠文件中之用語"作為主產物之丙烯酸”及，，作為副產 物之苯甲酸’僅意謂部份氧化反應之產物氣體混合物中丙 • 烯酸含量明顯高於笨甲酸。換言之，丙烯酸為部份氧化反 應之所要目標產物，而苯曱酸為基本上不希望有之副產 物。 根據本發明之方法特別適用於彼等丙烯酸含量為至少85 • 重里％ ’或至少90重量％，或至少95重量％，或至少96重 里％，或至少97重量。/。，或至少98重量％，或至少99重量 % ’或至少99·5重量％或99.5重量％以上之液相p*。 在該方法中，在液相ρ*之所有上述丙烯酸含量下（且當 然亦包括液相1>*中8〇重量％之丙稀酸含量），苯甲酸含量可 125528.doc -12- 200838848 占丙烯酸含量。.1重量%。至2〇重量%。，或。.2重量 :。旦。/ f°，或0·3重量％。至10重量％。，或U重量％。至8 里。。，或0.5重量％。至6重量％。，或〇 75重量％。至4重量 ‘ ’或1重量至3曹詈y . 旦 〇。一般而言，液相P*之苯甲酸含 里不超過丙烯酸含量的1⑽ 里里/σ°通常不超過75重量 〇〇或不超過50重量％0。根據本發日月方；^ # Ρ*中笪审納— 料發明方法尤其適用於液相 中本(不為〇且)為液相Ρ*中之苯甲 ㈣重量。/❶，或至少75重量 … 125#旦。/々 乂 1叫重里％，或至少 U5重里/〇,或至少15〇重量％， 200重量％，4至少25〇重量％ ;/75重置％，或至少 400會旦〇/ ^ 5 ^ 300重量％，或至少 重里/。，或至少500重量％時。當 王甲夕、右+ 侍根據本發明處 理之液相p*亦可不包含任何苯甲酸。 發明之操作法使結晶移除法（移出液相 遠母液至少部份再循環至 -錄赦八雜 俯衣至用於自液相p獲得液相p*之至少 應之二==及7或再循環至用於將氣相部份氧化反 P(通常在㈣Ρ物巾的㈣酸及笨？1组合轉化為液相 ，在所使用的包含分離内填物之分 至Γ種方法時，根據本發明之方法特別有效。 以：Γ:Γ吏:特異之結晶分離方法及非特異之分離方法 化物化合物之非均相催化部份氣相氧 化反應的產物氣體混合物中獲得液相Ν DE-A 19606877中已知者。 土本、、口構係自 非特異分離方法之定義 分離方法時形成的相之組成之分：、=產物且在採用該 戍之刀離過程與待分離混合物中 125528.doc -13- 200838848 之組成具有顯著相關性 的刀離方去，而本發明之結晶處理 法馮一種丙烯酸晶辦 … 的組成與液相p*之組成大體上獨立 (理想上元全獨立）之姓 特異刀離方法。換言之，在結晶之特 異分離方法中，就熱力 ' 達成所要分離作用，而冑立早_平衡即足以 點而士，y η 在非特刀離方法中，就熱力學觀 ^ /，’、.八建立若干連續平衡（參見：麥凱布-奚禮 (M^Cabe-Tluele)分離階段）以便產生顯著分離作用。、 若組合一種特里公雜 眭“減 離方法及至少一種非特異分離方法 广在連、，操作該製程下，由於母液富含苯甲酸，故苯甲 酸會因母液再循環而積聚在待根據本發明處理之液相P* 2，因此根據本發明方法在此方面具有提高之重要性。換 :之邓伤非均相催化之氣相氧化反應之產物氣體混合物 中即使相當低之苯甲酸含量仍可能逐漸變成嚴重問題，而 =智魏#輯本發㈣發現有規律地切或等於15 之（以及方法為主）來處理。在損耗係數Abza小於15之 狀況下，如所述進行之製程 、 双手將極低。尤其在工業規 才果上所需之效率僅能依贵振 :广依罪根據本發明方法中有規律地大於 或等於15之Abza達成。 然而，基於增加產量的目的，當根據本發明方法中獲得 的母液進一步結晶時或當同揭 、 』樣糟由結日日處理之非特異分離 中產生的包3苯甲酸之次要物流時，剛提及之事實亦 適用。 本發明之液相P*結晶處理法原則上不受任何限制，包括 用於自母液中移除晶體之方法（可採用所引用先前技術文 125528.doc 200838848 件中詳述的所有母液/晶體移除方法） 之：：，其可以-或多個階段連續或分批進行个 :，其亦可依分段結晶法進行。通常地，在…Γ: :::產生比所提供液相P'純度更高(尤其不甲： 的丙烯酸晶體之所有階段稱為文 為汽提階段。…山 p “又所有其他階段則 行，=段；適當地，該多段式方法係藉由逆流原理進 … 各階段中結晶後，自母液移出晶體，特 段之該等晶體則呈次於最高之純度饋入，而該特定階段: 結晶殘質則以次於最低之純度饋入。 。-般而言’在結晶移除期間液相之溫度在_25。。與川 C之間，特別在+^它與^它之間。 舉例而言，根據本發明之方法可以分層結晶法進行（參 看，DE-A 2606364、ep_a 616998、Ep_A 6他〇及心 776875)。在該結晶法中’晶體係以連續之穩固勸附層的 形式象析出。依靠殘餘嫁體簡單地流出而使沈積之晶體鱼 殘留之殘㈣體（母液）分離。原則上，在,,靜態"分層結晶 方法及"動態"分層結晶方法之間加以區別。液相p*之動態曰 分層結晶法的特徵為液相p*之強制對流。此可藉由使液相 P*以完全流經管子’藉由喷淋膜形式引入液相例如根 據EP-A 616998)或藉由將惰性氣體引入液相p*中或藉由脈 衝法引入，進行泵抽式循環來達成。 在靜態方法中，液相P*處於靜止狀態（例如，在管束或 板式熱交換器中）且因副側上之溫度緩慢降低而層層沈 積。其後，將殘餘熔體（母液）排出，雜質量較高之餾份因 125528.doc •15- 200838848 溫度緩慢增加而自晶體層滲出，且隨後將純產物完全熔融 (參看，WO 01/77056)。 然而，根據本發明，本發明之結晶步驟在該文件中所述 之所有液相P*之狀況下最好根據WO 01/77056、WO 02/055469及WO 03/078378之教示以懸浮結晶法進行。 一般而言，藉由冷卻液相P*、苯曱酸含量低於待純化液 相P*之丙烯酸晶體與苯甲酸含量高於待純化之液相P*之殘 留之殘餘熔體（母液）（以特定總量為基準計之相對量），得 到包含懸浮之丙烯酸晶體的晶體懸浮液。丙烯酸晶體可直 接在懸浮液中生長且/或在冷卻之壁上層層沈積，隨後可 刮下且再懸浮於殘餘熔體（母液）中。 根據本發明可使用 WO 01/7705 6、WO 02/05 5469、WO 03/078378 中及在 Research Disclosure 資料庫第 496005 號（在 2005年8月公開）中詳述之所有懸浮結晶器及懸浮結晶方 法。一般而言，所產生之丙烯酸晶體懸浮液具有20重量％ 至40重量％之固體含量。 此外，在上述WO公開案中詳細說明之所有方法適用於 分離已形成之懸浮晶體及殘留之母液（例如，機械分離方 法，諸如離心）。根據本發明較佳為在洗務柱中分離。較 佳為強制輸送沈積丙烯酸晶體的洗滌柱。晶體床中之晶體 體積分率一般達到大於〇 · 5之值。一般而言，洗務柱在0.6 至0.75之值下操作。所使用之洗滌液體宜為在洗滌柱中預 先純化（移除）之丙烯酸晶體的熔體。該洗滌法通常以逆流 形式實現。根據本發明之方法因而特別包含包括以下方法 125528.doc -16- 200838848 步驟之方法： a) 使丙烯酸自液相P*中結晶析出 殘餘相）中分離丙烯酸 曰曰 b) 自殘留母液（殘餘熔體，液體 體； 〇使移除之丙稀酸晶體至少部份熔融及 至步驟b)及/或步驟 d)使熔融丙烯酸晶體至少部份再循環 中0Comprehensive internal studies have now shown that when the heterogeneously catalyzed partial oxidation of a q precursor compound (eg, propylene), the I precursor compound (eg, propylene) also contains butadiene or is partially oxidized. When the compound can be converted into a dibutyl compound during the reaction, '$ citrate may be a by-product of the acrylic acid formation method. The reason for the formation of benzoic acid is probably the Deer-Ade of C3 dienophiles (such as propylene, acrolein and acrylic acid) which are present in the reaction gas mixture of the heterogeneously catalyzed partial oxidation reaction. The Diels_Alder) reaction, which is likely to continue the heterogeneously catalyzed oxidative dehydrogenation of the adduct to form an aromatic compound. The latter is probably catalyzed by the same catalyst as the actual target gas phase oxidation reaction. If appropriate, slight contamination of the crude product of the q precursor compound containing o-xylene (e.g., crude propylene) may also be responsible for the formation of by-products of benzoic acid. The use of a highly active multi-metal oxide catalyst (or a catalytic increase in volume/specific activity in the direction of increased reactant conversion) is additionally carried out using steam as an inert diluent gas, and relative to the county / 卜 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Precursor compound (for example, propylene in the two-stage partial oxidation reaction of propylene forming acrylic acid, or partial oxidation of acrylic acid to acrylic acid 125528.doc 200838848 It seems that the reaction temperature and conversion of acrolein in the reaction stage, or acrolein in the partial oxidation of acrolein to form acrylic acid, or propane in the partial oxidation of propane to form a propionic acid, also appear to increase. Promotes the formation of benzoic acid by-products. Supports the facts of the above hypothesis. In many cases it was found that only benzaldehyde, but not benzoic acid, is a by-product of the formation of acrylic acid. Benzoic acid is generally accompanied by benzaldehyde as a by-product of acrylic acid. Both of the base and the benzic acid are undesired acrylic concomitants. The undesired reason is that it is a compound which is not completely harmless but has considerable reactivity. (This applies correspondingly to esters of benzoic acid.) Therefore, when using the obtained acrylic acid and/or its alkyl ester to prepare a polymer which can be used in the sanitary field (for example, a water-absorbing polymer in a diaper), it must be ensured The acrylic acid used and/or the alkyl acrylate used is completely free of benzoic acid and benzaldehyde. It is well known that acrylic acid can be heterogeneously catalyzed from a c3 precursor compound of acrylic acid (for example, propylene) by a combination of different separation methods. Part of the gas phase oxidation • reaction product gas mixture removal. The combination used under certain conditions - generally depends on the type of non-acrylic minor component of the product gas mixture and summer, and is generally specified by acrylic acid The purpose of the specified acrylic acid depends on the purity. * The main components of the different separation methods are usually separated by thermal separation. The thermal separation method is guided by a gas (rise) and liquid (falling) flow in a countercurrent form in a separation column containing the separated internal charge, and heat and mass transfer occurs due to a gradient between the feed streams and finally causes The separation is to occur in the separation column. I25528.doc 200838848 Examples of such thermal separation methods are (partial) condensation, staged condensation (see Μ-A 245 32) and Seiko. The separation obtained here is based in particular on propylene. The difference in boiling point between the minor components of the acid and non-acrylic acid. Another example is the absorption method. This separation is based in particular on the different solubility of the secondary components of acrylic acid and non-acrylic acid in the liquid. The method (the stripping gas absorbs components having different affinities from the liquid and is present in dissolved form) and the thermal separation method of desorption (reverse process of absorption; removal of substances dissolved in the liquid phase by lowering the partial pressure). The term "thermal separation method" also includes azeotropic distillation and rectification (which uses an acrylic acid and a minor component (a component of a non-acrylic acid in a partial oxidation reaction gas mixture) to form an azeotrope with an added entrainer. Different trends). The difference between the boiling point of acrylic acid (14 TC at i atmosphere) and the boiling point of benzaldehyde (178.rC at 1 atm) is generally insufficient to remove a large amount of benzaldehyde from acrylic acid of appropriate complexity using the thermal separation method described above. The latter is usually removed only when additionally utilizing the different reactivity of benzaldehyde and acrylic acid with the so-called aldehyde • scavenger (W〇 3/014172) (for example, amine hydrazine bicarbonate). The reaction of the aldehyde with the aldehyde scavenger forms a new minor component whose boiling point deviates from the boiling point of the acrylic acid to a greater extent than the aldehyde itself deviates from the boiling point of the acrylic acid, so that after the reaction with the aldehyde scavenger is completed, the rectification route can be used. Remove in large numbers in a simple way. Alternatively, EP-A 1 159 249 discloses the separation of benzamidine and acrylic acid in a product gas mixture of a partial oxidation reaction by combining a thermal separation process (segment condensation) with crystallization (suspended crystallization) (see also DE-A 10247240) 〇 In contrast to the above, the difference between the boiling point of acrylic acid (141 ° C at 1 atm) 125528.doc 200838848 and the boiling point of benzoic acid (250 ° C at 1 atm) is so large that when used Acrylic acid and benzoic acid can usually be separated in large quantities based on the thermal separation method of different boiling points of the components of the mixture. (See, = 10336386. DE-A 19740252 ^ DE-A 10247240) (^^^^^ parts often in phenylhydrazine After acid removal, it is removed by crystallization). However, this thermal separation = a disadvantage that the fraction containing the acrylic acid in an enriched form must be extracted from the fraction = column containing the separated internal charge above the feed of the mixture to be separated in the column. However, it is extremely necessary to supply a heat source at this time because the complete burst of acrylic acid consumes a lot of energy (high boiling point, high evaporation enthalpy, and multiple evaporation due to reflux). SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an acrylic acid and a benzene which are present as a main product and a by-product in a product gas mixture of a partially heterogeneously catalyzed gas phase oxidation reaction of a q-precursor compound of acrylic acid. The method of formic acid 'it does not require the above-mentioned separation method which consumes a large amount of energy. Accordingly, there is provided a component of an acrylic acid and a benzoic acid and other product gas mixture as a main product and a by-product in a product gas mixture of a partially heterogeneously catalyzed gas phase oxidation reaction of a q-precursor compound of acrylic acid, wherein acrylic acid is contained. And benzoic acid, together with other components of the product gas mixture having a boiling point lower than that of acrylic acid, are converted from the product gas mixture to the liquid phase P, and the boiling point is removed from the obtained liquid phase p using at least one thermal separation method to be lower than the benzoic acid and the acrylic acid. a component (based on the boiling point of the pure substance at 1 atm) (but not containing benzoic acid; "not contained" means 10% by weight or less, preferably 5% by weight, based on the benzoic acid content in the liquid phase p, respectively. Hereinafter, even more preferably 125528.doc •10-200838848 is 3% by weight or less or 2% by weight or less or 1% by weight or less, and most preferably 〇·75 mil A or less, or 1.1% by weight or less 'or 0 weight %), leaving at least 80% by weight of acrylic acid and at least 0.1% by weight based on the acrylic acid content. (yield at least 0.2% by weight, or at least 〇3% by weight, or at least 〇·4 by weight, or at least 0.5% by weight, or at least 〇·75% by weight., or at least 1% by weight of benzoic acid The liquid phase P*, the method comprises separating the acrylic acid from the liquid phase p* and separating it from the benzoic acid, the acrylic acid is accumulated in the formed crystal, and the benzoic acid is in the residual mother liquid. [Embodiment] According to the invention The method is based on the surprising finding that the loss coefficient A (based on the 5 hai method) is regularly greater than or equal to 15. It is understood that the loss factor abza generally means that the benzoic acid remaining in the mother liquor remains in the crystal. The content ratio of benzoic acid (expressed in the total amount of the mother liquor or the total weight of the crystal in each case). Usually, the crystal/mother liquid removal amount is 90% by weight or more, and preferably % Above 70% by weight, or 97% by weight or 98% by weight or 99% by weight, is sufficient to determine ABZA (the effect of residual moisture content on the crystal is negligible, slightly). A center of greater than or equal to 15 is expressed in acrylic acid crystals. Formation Substantially no benzoic acid enters the crystal. This is the basis for the significant efficiency of the process of the invention. When the secondary components of acrylic acid are diacrylic acid (aDA), acetic acid (aAA) and propionic acid (APA), the corresponding loss factor is usually It is a value less than or equal to 1 。. In other words, it also enters the acrylic crystal, and only 1 惶 can be extracted from the crystals by, for example, difficulty in proper washing. 125528.doc -11- 200838848 In other words, use The crystallization process generally requires the use of a less efficient and costly multistage crystallization process from the removal of such impurities from acrylic acid, such as, for example, the multi-stage combination of dynamic and static crystallization as suggested in EP-A 616 998. And also requires a multi-stage process, at least one dynamic crystallizer and at least one static crystallizer. Optimally, acrylic acid is formed under special constraints of crystallization (see, in particular, WO 03/078378 and WO 〇 1/77056) The crystals, which are subsequently washed with a pure acrylic acid melt, remove the acetic acid and propionic acid in the crystals quite effectively. The larger the ABZA, the more benzene is removed by crystallization. The acid process is more attractive. In view of the above experiments, the process of the present invention can be used in the formation of acrylic acid suitable for superabsorbent, which crystallizes the crystal with a pre-purified acrylic melt after the crystallization stage, and can be substantially moved in large quantities. In addition to the liquid phase p*, the benzoic acid impurity which hinders the use is used. In the far document, the term "acrylic acid as the main product" and, as a by-product of benzoic acid, are only meant to be part of the oxidation reaction product gas mixture. The acrylic acid content is significantly higher than the stupid acid. In other words, acrylic acid is the desired target product of the partial oxidation reaction, and benzoic acid is a substantially undesirable by-product. The method according to the invention is particularly suitable for the acrylic acid content. It is at least 85 • weight % ' or at least 90% by weight, or at least 95% by weight, or at least 96% by weight, or at least 97% by weight. /. Or at least 98% by weight, or at least 99% by weight or at least 99.5% by weight or 99.5% by weight of liquid phase p*. In this method, the benzoic acid content can be 125528.doc -12-200838848 in all of the above acrylic acid contents of the liquid phase ρ* (and of course also including the acrylic acid content of 8 〇% by weight in the liquid phase 1 >*). Acrylic content. .1% by weight. Up to 2% by weight. ,or. .2 weight: Dan. / f°, or 0·3 wt%. Up to 10% by weight. , or U weight%. Up to 8 miles. . , or 0.5% by weight. Up to 6% by weight. , or 〇 75 wt%. To 4 weights ‘ or 1 weight to 3 Cao y. Dan 〇. In general, the liquid phase P* of benzoic acid contains no more than 1 (10) lin / σ ° of the acrylic acid content and usually does not exceed 75 wt% or not more than 50 wt%. According to this issue, the date of the invention; ^ # Ρ 笪 笪 — — — 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 料 发明 发明 发明 发明 发明/❶, or at least 75 weights... 125# Dan. /々乂1 is called heavy %, or at least U5 heavy/〇, or at least 15% by weight, 200% by weight, 4 at least 25〇% by weight; /75 reset %, or at least 400 meeting denier / ^ 5 ^ 300 % by weight, or at least heavy /. , or at least 500% by weight. The liquid phase p* treated by Wang Jiaxi and Right + according to the present invention may also not contain any benzoic acid. The method of the invention allows the crystallization removal method (the removal of the liquid phase far mother liquid is at least partially recycled to - the recording of the liquid phase p* to obtain at least two of the liquid phase p* from the liquid phase p == and 7 or Recycling to a gas phase partial oxidation anti-P (usually in the (four) smear of the (four) acid and stupid 1 combination into a liquid phase, in the use of the separation of the inclusion of the separation of the method, according to The method of the present invention is particularly effective. Γ: Γ吏: a specific crystal separation method and a non-specific separation method, a heterogeneously catalyzed partial gas phase oxidation reaction of a product gas mixture to obtain a liquid phase Ν DE-A It is known from 19606877. The composition of the phase formed by the method of separation of non-specific separation methods from the non-specific separation method is: , = product and in the mixture of the process and the mixture to be separated. The composition of doc -13- 200838848 has a significant correlation with the knife away, and the composition of the crystallization treatment method of the present invention is substantially independent of the composition of the liquid phase p* (ideally all independent) The surname is a special knife-off method. In other words, at the knot In the specific separation method, the thermal force 'achieves the separation effect, and the _立早_balance is enough to point, y η in the non-special knife separation method, the thermodynamics view ^ /, ', . See: M^Cabe-Tluele separation stage) in order to produce significant separation. If a combination of Terry's hodgepodge method and at least one non-specific separation method is widely used, operation In this process, since the mother liquor is rich in benzoic acid, the benzoic acid will accumulate in the liquid phase P* 2 to be treated according to the invention due to the recycling of the mother liquor, so that the method according to the invention has an important importance in this respect. Even a relatively low benzoic acid content in the product gas mixture of the heterogeneously catalyzed gas phase oxidation reaction of Deng's injury may gradually become a serious problem, and = Zhiwei #辑本发(四) found to be regularly cut or equal to 15 ( And the method is mainly for processing. In the case that the loss coefficient Abza is less than 15, the process and the hands will be extremely low as described above. Especially in the industrial regulations, the required efficiency can only be based on the levy: According to the method of the invention, Abza is regularly greater than or equal to 15. However, based on the purpose of increasing the yield, when the mother liquor obtained in the method according to the invention is further crystallized or when the same is treated, The facts just mentioned are also applicable when the secondary stream of the package 3 benzoic acid produced in the non-specific separation is also applicable. The liquid phase P* crystallization treatment method of the present invention is not limited in principle, including for removing crystals from the mother liquor. The method (which can be used in all of the mother liquor/crystal removal methods detailed in the prior art reference 125528.doc 200838848):: it can be carried out continuously or in batches in multiple stages: Performed by fractional crystallization. Generally, the Γ::: produces a higher purity than the supplied liquid phase P' (especially not all of the phases of the acrylic crystal are called the stripping stage.... mountain p "all other stages, = segment; suitably, the multi-stage method is carried out by the principle of countercurrent... After crystallization in each stage, the crystal is removed from the mother liquor, and the particular segment of the crystal is fed second to the highest purity, and the specific stage: The quality is fed in the next lowest purity. - Generally speaking, the temperature of the liquid phase during crystallization removal is between _25 and C, especially between +^ and ^ it. The method according to the invention can be carried out by layered crystallization (see, DE-A 2,606,364, ep_a 616,998, Ep_A 6 and 776,875). In this crystallization method, the crystal system is in the form of a continuous stable adhesion layer. Like the precipitation. The residual (four) body (mother liquor) is separated by the residual nutrient simply flowing out. In principle, the static "stratified crystallization method and "dynamic" layered crystallization method The difference between the liquid phase p* dynamic 曰 layered crystallization method The forced convection of the liquid phase p* can be achieved by introducing the liquid phase P* into the liquid phase by means of a spray film in a complete flow through the tube, for example according to EP-A 616998, or by introducing an inert gas into the liquid phase. In p* or by pulsed introduction, a pumping cycle is achieved. In the static method, the liquid phase P* is at rest (for example, in a tube bundle or plate heat exchanger) and because the temperature on the secondary side is slow Lower layer deposition. Thereafter, the residual melt (mother liquor) is discharged, and the fraction with higher impurity content oozes out from the crystal layer due to the slowly increasing temperature of 125528.doc •15-200838848, and then the pure product is completely melted ( See, WO 01/77056). However, according to the invention, the crystallization step of the invention is preferably in accordance with WO 01/77056, WO 02/055469 and WO 03/ in the case of all liquid phases P* described in the document. The teaching of 078378 is carried out by suspension crystallization. Generally, the content of acrylic acid crystals and benzoic acid in the liquid phase P* and the benzoic acid content lower than the liquid phase P* to be purified is higher than the liquid phase P* to be purified. Residual residual melt (mother liquor) (phase based on a specific total amount) A crystalline suspension containing suspended acrylic crystals is obtained. The acrylic crystals can be grown directly in the suspension and/or deposited layer by layer on the cooled wall, which can then be scraped off and resuspended in the residual melt (mother liquor). All suspension crystallizers and suspension crystallization detailed in WO 01/7705 6, WO 02/05 5469, WO 03/078378 and in Research Disclosure Library No. 496005 (published in August 2005) can be used in accordance with the present invention. method. In general, the resulting acrylic crystal suspension has a solids content of from 20% to 40% by weight. Furthermore, all of the methods detailed in the above WO publication are suitable for separating the formed suspended crystals and residual mother liquor (e.g., mechanical separation methods such as centrifugation). According to the invention it is preferred to separate in the wash column. It is preferred to forcibly transport a wash column for depositing acrylic crystals. The volume fraction of crystals in the crystal bed generally reaches a value greater than 〇 · 5 . In general, the wash column operates at a value between 0.6 and 0.75. The washing liquid used is preferably a melt of acrylic crystals previously purified (removed) in a washing column. This washing method is usually carried out in a countercurrent form. The process according to the invention thus comprises in particular a process comprising the following steps 125528.doc -16 - 200838848: a) separating the acrylic acid from the residual phase of the liquid phase from the liquid phase P*) b) self-retaining mother liquor (residual melting) a liquid body; at least partially melting the removed acrylic acid crystals and at least partially recycling the molten acrylic crystals to step b) and/or step d)
進行步驟b)之較佳方式為使μ預先㈣、㈣且再循 %入步驟b)中之丙烯酸晶體進行逆流洗滌。 、當採用根據本發明之方法時，根據本發明液相P*宜(但 並不疋）包έ水，此係因為根據wo 01/77056及wo 03/078378之教示，在水存在下所形成之丙烯酸晶體對於 隨後自殘留母液巾分離晶料，可產生特別㈣之晶體形 式。此情形在以懸浮結晶形式進行結晶時尤其適用，甚至 在隨後於洗滌柱中移除母液時更適用，甚至當所使用之洗 滌液體為已在洗滌柱中純化之丙烯酸晶體的熔體時更適 用0 換言之，根據本發明之方法特別包含將待藉由結晶處理 之液相Ρ*在低溫條件之作用下轉化為由丙烯酸晶體及液體 殘餘相（殘餘熔體）組成之晶體懸浮液的方法，丙烯酸晶體 中之苯甲酸的重量比小於液相Ρ*中之苯甲酸的重量比且液 體殘餘相（母液）中之苯甲酸的重量比大於液相Ρ*中之苯曱 酸的重量比，若適當時，以機械方式自晶體懸浮液中移除 一部份殘留母液，且在洗滌柱中將丙烯酸晶體與殘留母液 125528.doc •17- 200838848 分開，其限制條件為： a) 液相P*中以重量計之水含量占其中丙烯酸含量之至少50 ppm或0.20%至20%且經常達15%或達10%之水，及 b) 所使用之洗滌液體為已在洗滌柱中純化之丙烯酸晶體的 熔體。 此外，根據本發明之上述製程中（或相當常採用根據本 發明之方法時）液相P*之水含量宜占液相P*中丙烯酸含量 之0.2重量％或0.4重量％至8重量％或至10重量％或至20重量 %。 所有上述内容特別適用在洗滌柱為強制輸送丙烯酸晶體 的洗滌柱時，特定言之，當其為根據WO 01/77056且如其 中詳述操作之液壓洗條柱或機械洗條柱時。 所有上述内容特別適用在根據WO 03/041832及WO 03/041 833之教示設計且操作洗滌柱時。 原則上，在使用根據本發明之分離方法前的非均相催化 部份氣相氧化反應可依先前技術已知之方法執行（除了用 於獲得起始反應氣體混合物之粗C3前驅物化合物可能具有 較低純度的情況以外）。The preferred mode of carrying out step b) is to carry out countercurrent washing of the acrylic crystals in step b) by pre- (4), (4) and again. When the method according to the invention is employed, the liquid phase P* according to the invention is preferably (but not 疋) encased in water, which is formed in the presence of water according to the teachings of WO 01/77056 and WO 03/078378. The acrylic crystals are then subjected to a separate (4) crystal form for the subsequent separation of the crystal from the residual mother liquor. This is especially true when crystallization is carried out in suspension crystal form, even when the mother liquor is subsequently removed from the wash column, even when the wash liquid used is a melt of acrylic crystals that have been purified in the wash column. 0 In other words, the method according to the invention comprises in particular a method for converting a liquid phase 待* to be crystallized by a crystallization treatment into a crystal suspension composed of an acrylic crystal and a liquid residual phase (residual melt) under the action of a low temperature condition, acrylic acid The weight ratio of benzoic acid in the crystal is less than the weight ratio of benzoic acid in the liquid phase Ρ* and the weight ratio of benzoic acid in the liquid residual phase (mother liquor) is greater than the weight ratio of benzoic acid in the liquid phase Ρ*, if appropriate When a portion of the residual mother liquor is mechanically removed from the crystal suspension, and the acrylic crystals are separated from the residual mother liquor 125528.doc • 17- 200838848 in the wash column, the constraints are: a) liquid phase P* Water having a water content of at least 50 ppm or 0.20% to 20% by weight of the acrylic acid and often up to 15% or up to 10%, and b) the washing liquid used has been purified in a washing column The melt of acrylic crystals. Furthermore, the water content of the liquid phase P* in the above process according to the invention (or quite often when the process according to the invention is employed) is preferably 0.2% by weight or 0.4% by weight to 8% by weight of the acrylic acid content in the liquid phase P* or Up to 10% by weight or to 20% by weight. All of the above is particularly applicable when the wash column is a wash column for the forced transport of acrylic crystals, in particular when it is a hydraulic wash column or mechanical wash column according to WO 01/77056 and as detailed therein. All of the above are particularly applicable when the wash column is designed and operated in accordance with the teachings of WO 03/041832 and WO 03/041 833. In principle, the heterogeneously catalyzed partial gas phase oxidation reaction prior to the use of the separation process according to the invention can be carried out according to methods known in the prior art (except that the crude C3 precursor compound used to obtain the initial reaction gas mixture may have a comparative Outside the case of low purity).
換言之，其可（例如）依 DE-A 10351269、DE-A 10245 585、 DE 1020050227988、EP-A 1695954、DE-A 10351269、EP-A 990636、EP-A 1106598、DE-A 102005010111、DE-A 1020050130399 、 DE-A 102004025445 、 DE-AIn other words, it can be, for example, according to DE-A 10 351 269, DE-A 10 245 585, DE 1020050227988, EP-A 1 695 954, DE-A 10 351 269, EP-A 990 636, EP-A 1 106 598, DE-A 10 2005 010 111, DE-A 1020050130399 , DE-A 102004025445 , DE-A
102004021764、DE-A 10338529、DE-A 10337788、DE-A 10360396、DE-A 10316465、DE-A 10313210、DE-A 125528.doc -18 - 200838848102004021764, DE-A 10338529, DE-A 10337788, DE-A 10360396, DE-A 10316465, DE-A 10313210, DE-A 125528.doc -18 - 200838848
10313214、DE-A 10313213、DE-A 10313212、DE10313214, DE-A 10313213, DE-A 10313212, DE
102005062026.4、DE-A 10313211、DE-A 10313208及 DE-A 103 13209以及該等文件中所述之先前技術中所述執行。102005062026.4, DE-A 10313211, DE-A 10313208, and DE-A 103 13209, as described in the prior art described in these documents.
詳a之，根據本發明之方法適用於由丙烯形成丙烯酸之 兩段式非均相催化部份氣相氧化反應的產物氣體混合物。 在第一反應階段中，將丙烯基本上部份氧化為丙烯醛，且 在第二反應階段中，將在第一反應階段中獲得之丙烯醛部 份氧化為丙烯酸。通常將（若適當）補充有分子態氧或含分 子態氧與惰性氣體之混合物的丙烯醛作為第一反應階段之 產物氣體混合物之成份饋入第二反應階段。 根據本發明之方法㈣適用在㈣部份氧化反應中之丙 。烯轉化率Up大於或等於91莫耳％，或大於或等於Μ莫耳 %，或大於或等於93莫耳％，或大於或等於94莫耳％，、或 ，於或等於95莫耳％，或大於或等於％莫耳％，或大於或 等於97莫耳％ ’或大於或等於％莫耳％，或大於或等於的 莫耳％時。 根據本發明方法亦特別適用在丙烯醛部份氧化反岸中 =浠經轉化州為大於或等於96莫耳％，或大於或等於 、耳％’或大於或等於98莫耳％，或大於或等於98 5莫 此係因為當使用相同 終以單次通過催化劑床 特定反應階段中選擇較 ❶大於或等於99莫耳％，或大於或等於99.5莫耳 大於或等於99.8莫耳％或99.8莫耳％以上時。 催化劑系統時，上述轉化率（其始 的反應氣體混合物為基準）通常在 高反應溫度及/或使用包含具有較 125528.doc -19- 200838848 高活性之催化劑的催化劑填料時達成。兩者皆促進產生苯 甲酸副產物。 、上述内*特別適用纟已陳述的由丙烯形《丙烯酸之兩段 式部份氧化反應之狀況下。In detail, the process according to the invention is applicable to a product gas mixture of a two-stage heterogeneously catalyzed partial gas phase oxidation reaction of acrylic acid from propylene. In the first reaction stage, propylene is substantially partially oxidized to acrolein, and in the second reaction stage, the acrolein fraction obtained in the first reaction stage is oxidized to acrylic acid. Acrolein supplemented with molecular oxygen or a mixture of molecular oxygen and an inert gas is usually fed, if appropriate, as a component of the product gas mixture of the first reaction stage to the second reaction stage. The method (4) according to the present invention is applicable to the C in the (IV) partial oxidation reaction. The olefin conversion rate is greater than or equal to 91% by mole, or greater than or equal to Μmol%, or greater than or equal to 93% by mole, or greater than or equal to 94% by mole, or, at or equal to 95% by mole, Or greater than or equal to % Mo %, or greater than or equal to 97 Mo % ' or greater than or equal to % Mo %, or greater than or equal to Mo %. The method according to the invention is also particularly suitable for use in acrolein partial oxidation in the reverse shore = 浠 transformed state is greater than or equal to 96 mol%, or greater than or equal to, ear % ' or greater than or equal to 98 mol %, or greater than or Equal to 98 5 is because the choice is greater than or equal to 99 mole %, or greater than or equal to 99.5 moles greater than or equal to 99.8 mole % or 99.8 moles when using the same end in a single pass through the catalyst bed. When it is above %. In the case of a catalyst system, the above conversion (based on the starting reaction gas mixture) is usually achieved at high reaction temperatures and/or when a catalyst packing comprising a catalyst having a higher activity than 125528.doc -19-200838848 is used. Both promote the production of benzoic acid by-products. The above-mentioned inner* is particularly applicable to the two-stage partial oxidation reaction of acrylic acid which has been stated.
/於。3前驅物化合物之非均相催化部份氧化反應的催化 M SJ定床。用於丙烯部份氧化反應的特別有活性 (固定催化劑為彼等活性組合物為比表面積為(Μ m2/gi m2/g，或 〇·2 mV^5〇 m2/g，或 i 瓜2/§至2〇 m2/g，或 2 111 /g至1〇 m /g之多金屬氧化物組合物的催化劑。 、此外，當其多金屬氧化物活性組合物的最常見孔徑數值 為0·1 μιη至1 μηι時，有利於部份氧化丙稀形成丙婦搭之 (固定床）催化劑活性。 尤其當以上述最常見之孔徑數值及上述比表面積中之一 與多金屬氧化物活性組合物組合時，可提高用於丙稀形成 丙浠醛之部份氧化反應的（固定床）催化劑活性。 同時，提高活性之上述多金屬氧化物活性组合物（催化 劑）的總孔體積宜為（Μ WgM.OO ml/g，通常為。Μ⑽ 至 〇·80 ml/g，或 〇·2〇 ml/g至 0.40 ml/g。 甚至當用於丙烯形成丙烯醛之非均相催化部份氧化反應 的催化劑包含上述催化劑時經常已完全足夠。 用於丙烯醛部份氧化反應（特別在丙烯形成丙烯酸之兩 段式部份氧化反應的第二反應階段時）的特別有活性之（固 定床）催化劑為彼等活性組合物為比表面積為〇1 ^仏至 1 50 m2/g ’ 或 〇.2 mVg至 50 mVg ’或！心至 2〇 瓜2/§，或 2 125528.doc -20- 200838848 m2/g至l〇 m2/g之多金屬氧化物組合物的催化劑。 此外’當其多金屬氧化物活性組合物的最常見孔徑數值 為〇.1 μιη至1 0瓜時，有利於丙烯醛形成丙烯酸之部份氧化 反應的（固定床）催化劑活性。 尤其當以上述最f見之孔徑數值及上述比表面積中之一 與多金屬氧化物活性組合物組合存在時，可提高用於丙婦 醛形成丙烯酸之部份氧化反應的（固定床）催化劑活性。/to. 3 Catalytic catalysis of heterogeneously catalyzed partial oxidation of precursor compounds M SJ fixed bed. It is particularly active for the partial oxidation of propylene (the fixed catalyst is such that the active composition has a specific surface area of Μ m2/gi m2/g, or 〇·2 mV^5〇m2/g, or i melon 2/ a catalyst for a multi-metal oxide composition of 2 〇 m 2 /g, or 2 111 /g to 1 〇 m /g. Further, when the multi-metal oxide active composition has the most common pore size value of 0·1 When μιη to 1 μηι, it is advantageous for partial oxidation of propylene to form a (fixed bed) catalyst activity, especially when combined with a multimetal oxide active composition in one of the most common pore size values and the above specific surface area. In this case, the (fixed bed) catalyst activity for partial oxidation of propylene oxide to propylene oxide can be increased. Meanwhile, the total pore volume of the above-mentioned multimetal oxide active composition (catalyst) for increasing the activity is preferably (Μ WgM .OO ml/g, usually Μ(10) to 〇80 ml/g, or 〇·2〇ml/g to 0.40 ml/g. Even when used for the heterogeneously catalyzed partial oxidation of propylene to acrolein The catalyst is often completely sufficient when it contains the above catalyst. Particularly active (fixed bed) catalysts for the reaction (especially in the second reaction stage of the two-stage partial oxidation of propylene to form acrylic acid) are those having a specific surface area of from 仏1 ^仏 to 1 50 m2 /g ' or 〇.2 mVg to 50 mVg 'or! Heart to 2 〇 2 / §, or 2 125528.doc -20- 200838848 m2 / g to l 〇 m2 / g of multi-metal oxide composition catalyst In addition, 'when the most common pore size value of the multi-metal oxide active composition is from 〇.1 μιη to 10 melon, it is advantageous for the (fixed bed) catalyst activity of acrolein to form a partial oxidation reaction of acrylic acid. When one of the above-mentioned most preferred pore diameter values and the above specific surface area is present in combination with the multimetal oxide active composition, the (fixed bed) catalyst activity for partial oxidation of acrylic acid to acrylic acid can be enhanced.
同時，具有提高活性之上述多金屬氧化物活性組合物 (催化劑）的總孔體積宜為（M…化至〜卯ml/g，通常為〇 2〇 ml/g至 0.80 ml/g，或 0.30 ml/g至 0·70 ml/g。 甚至當用於丙烯醛形成丙烯酸之非均相催化部份氧化反 應的催化劑包含上述催化劑時經常已完全足夠。 原則上，在上文詳述之兩種部份氧化反應中，在反應氣 體混合物之流動方向上的催化劑床（尤其為固定催化劑床） 之體積·比活性在流動路徑長度範圍内可為恆定的。然 而，在特定狀況下，當（固定）催化劑床之該體積-比活性於 反應氣體混合物之流動方向上增加至少一次（連續或突然 或逐步）時，根據本發明之方法的適用性特別提高。在所 有上述狀況下，當活性組合物不會隨流動路徑長度改變時 亦有利。 上述催化劑可為經塗佈之催化劑或未承載之催化劑。催 化劑之幾何形狀原則上可依需要變化。可能使用球形、多 邊形、固體圓柱形或環形。成型催化劑體之最長尺寸以1 mm至1〇 mm，或2 mm至8 mm為適當。咸了解，該最長尺 125528.doc -21- 200838848 寸意謂連接成型催化劑體表面上之兩點的最長直線。固定 催化劑床之體積比活性可藉由絲本上惰性之成型體（成 型稀釋體)適當稀釋催化劑而產生。該等惰性成型體之幾 何形狀基本上與成型催化劑體之幾何形狀-致。適用於該 等惰性成型Μ的材料原貝上為所有彼等亦適合作為適用於 根據本發明之經塗佈催化劑的載體材料。該等材料特定言 之為非多孔性氧化物，諸如，氧化鋁、二氧化矽、二氧化Meanwhile, the total pore volume of the above-mentioned multimetal oxide active composition (catalyst) having an increased activity is preferably (M... to 卯ml/g, usually 〇2〇ml/g to 0.80 ml/g, or 0.30) Ml/g to 0·70 ml/g. Even when the catalyst for the heterogeneously catalyzed partial oxidation of acrolein to form acrylic acid comprises the above catalyst, it is often completely sufficient. In principle, the two are detailed above. In the partial oxidation reaction, the volume/specific activity of the catalyst bed (especially the fixed catalyst bed) in the flow direction of the reaction gas mixture may be constant over the length of the flow path. However, under certain conditions, when (fixed) The suitability of the method according to the invention is particularly enhanced when the volume of the catalyst bed is increased at least once (continuous or abrupt or stepwise) in the direction of flow of the reaction gas mixture. In all of the above cases, when the active composition It is also advantageous not to vary with the length of the flow path. The above catalyst may be a coated catalyst or an unsupported catalyst. The geometry of the catalyst may in principle be varied as needed. It is possible to use a spherical shape, a polygonal shape, a solid cylindrical shape or a ring shape. The longest dimension of the shaped catalyst body is suitably 1 mm to 1 mm, or 2 mm to 8 mm. It is understood that the longest rule is 125528.doc -21 - 200838848 inch It means the longest straight line connecting the two points on the surface of the shaped catalyst body. The volume specific activity of the fixed catalyst bed can be produced by appropriately diluting the catalyst by a mold-inert molded body (molding dilution). The geometry of the inert molded body The shape is substantially the same as the geometry of the shaped catalyst body. The materials suitable for the inert shaped enamel are all of them which are also suitable as carrier materials for the coated catalysts according to the invention. Non-porous oxides, such as alumina, cerium oxide, dioxide
钍、一氧化鍅、碳化矽、矽酸鹽（諸如，矽酸鎂或矽酸鋁） 或塊滑石。 根據本發明’用於丙烯—丙烯酸部份氧化反應之提高活 性之催化劑的多金屬氧化物活性組合物適當地包含金屬元 素Mo、Fe及Bi。當其化學計量滿足下式I時其具有特別提 高之活性： M〇i2Bia Feb X!c x2d X3e X4f On (I) 其中： X1=鎳及/或鈷， X =鉈、鹼金屬及/或鹼土金屬， X3 =辞、磷、砷、硼、銻、錫、鈽、鉛及/或鎢， χ4=矽、鋁、鈦及/或鍅， a=〇 · 5 至 5， b = 0.01至5，較佳為2至4， c=0至1〇，較佳為3至1〇， d=0至2，較佳為〇·〇2至2， 125528.doc -22- 200838848 e=0至8，較佳為〇至5， f=〇至10 ，且 由⑴中除氛m卜之元素之原子價及&現:欠數決定的數值。 上述内容尤其適用於活性組合物具有關於比表面積及孔 體積已陳述之性質時。 根據本發明1於丙烯酸—㈣酸部份氧化反應之具有 提高活性之催化劑的多金屬氧化物活性組合物以包含金屬 元素Mo及V為適當。當其化學計量滿足下式II時其具有特 別提高之活性： M〇12 Va X\ x2c x3d X4e X5f X6g 〇n (n) 其中： X1=W、Nb、Ta、Cr及 /或 Ce， X2=Cu、Ni、Co、Fe、Μη及 /或 Zn， X3 = Sb及 /或 Bi， X4=—或多種驗金屬， x5=—或多種驗土金屬， X6=Si、A卜 Ti及 /或 Zr， a=l 至 6， b = 0.2至 4， c=0.5至 18， d=0至40 ， e=0至 2， f=0至 4， -23- 125528.doc 200838848 g = 0至40，且 n=由（II)中除氧以外之元素之原子價及出現次數決定的數 值。 在活性多金屬氧化物（II)中特別有活性之實施例為彼等 由通式II之代號的以下定義所涵括之實施例： X1==W、Nb及/或 Cr， X2=Cu、Ni、Co及/或 Fe， X3=Sb ， X4=Na及/或 K， X5=Ca、Sr及 /或 Ba， X6=Si、A1及 /或 Ti， a=l .5至 5， b = 0.5 至 2， c = 0.5 至 3， d=0至 2， e = 0至 0.2， f=0至1，且 n=由（II)中除氧以外之元素之原子價及出現次數決定的數 值。 有利地，c3前驅物化合物之部份非均相催化氣相氧化反 應係在管束反應器中執行。固定催化劑床係安置在管束反 應益之反應管中。液體熱載體（一般為金、 體或液體今 屬）環繞催化劑管流動，以便移除反應熱。 、 這兩種狀況下具有丙烯或丙烯醛之（固定 J催化劑床的裝 125528.doc -24- 200838848 載量可大於或等於70 L (STP)/L.h，或大於或等於9〇L (STP)/L.h，或大於或等於110 l (STP)/L.h，或大於或等於 130 L (STP)/L·]!，或大於或等於 14〇 l (STP)/L.h，或大於 或等於 160 L (STP)/L.h，或大於或等於 18〇 L (STP)/L.h， 或大於或等於240 L (STP)/L.h，或大於或等於300 L (STP)/L.h。 然而，一般而言，其小於或等於6〇〇 L (STp)/L.h(各該裝 載量數值係以固定催化劑床之體積為基準計，不包括任何 另外使用的僅由惰性材料組成之部分）。 在該文件中，咸了解，具有起始反應氣體混合物之（固 定）催化劑床的裝載量意謂每小時引導穿過丨公升（固定）催 化劑床之起始反應氣體混合物的量（標準公升）(L (STp)); 相應量之起始反應氣體混合物在標準條件下（亦即，在乃 °(：及1巴下）佔據之體積（公升））。（固定）催化劑床之裝載量 亦可僅以起始反應氣體混合物之一種組份為基準計。在彼 狀況下，其為作為相應起始反應氣體混合物之成份每小時 引V牙過1公升（固定）催化劑床之該組份的量（標準公升）。 在該文件中，咸了解惰性氣體一般為彼等在部份氧化反 應過程中分別單獨保持至少95莫耳❻/〇無化學變化之程度之 氣體，較佳為達到至少97莫耳％之程度，且最佳為達到99 莫耳％或99莫耳％以上之程度。 丙烯—丙烯醛部份氧化反應中之反應溫度一般為27(rc 至 450°C，或 280°C 至 42(TC，較佳為 300。(：至 380。(：。丙烯 駿—丙烯酸部份氧化反應中之反應溫度-般為2〇代至37〇 125528.doc -25- 200838848 C，或200°C 至 320°C，較佳為 220°C 至 300°C。 本發明之部份氧化反應中的操作壓力一般低於標準壓力 (例如，至高0.5大氣壓；使反應氣體混合物吸入）或高於梗 準壓力。通常，操作壓力值將為丨大氣壓至5大氣壓，常為 1.5大氣壓至3·5大氣壓。本發明之部份氧化反應中的操作 壓力通常不超過1〇〇大氣壓。 在部份氧化反應過程中作為氧化劑所需之分子態氧的可 用來源為空氣或沒有分子態氮之空氣。 一般選用於本發明之丙烯（形成丙烯醛）或丙烯醛（形成丙 烯酸）之部份氧化反應的催化劑應使得形成目標產物（丙烯 醛或丙烯酸）之選擇性大於或等於83莫耳％，常大於或等於 85莫耳％，或大於或等於88莫耳％，常大於或等於卯莫耳 %，或大於或等於93莫耳％或93莫耳％以上。 用於丙烯部份氧化反應（形成丙烯醛）之典型起始反應氣 體混合物可（例如）包含： 5體積％至12體積％之丙浠； 2體積％至15體積％之水； 大於或等於0體積％至10體積％之丙烷； 大於或等於0.1體積％至5體積％的除了丙烯、丙烧、 水、氧及氮之外之成份； 及充足分子態氧’其中分子態氧與丙烯之莫耳比為1 至3 ;以及 其餘為補足總量達到100體積％之分子態氮。 或者’用於丙稀部份乳化反應（形成丙婦駿）之起始反應 125528.doc -26- 200838848 氣體混合物可包含： 6體積％至10體積％之丙烯， 8體積％至18體積％之分子態氧， 6體積％至3〇體積％之丙烷，及 32體積％至72體積％之分子態氮。 用於丙烯—丙烯醛部份氧化反應之反應混合物亦可包含 高20體積％<h2。 用於丙烯醛部份氧化反應（形成丙烯酸）之起始反應氣體 響、混合物包含（例如）： 4體積％至8體積％之丙烯醛， 2體積％至9體積％之分子態氧， 〇體積％至3〇體積％之丙烷， 3〇體積％至75體積％之分子態氮，及 5體積％至30體積％之蒸汽， 或 φ 3體積％至25體積％之丙烯醛， 5體積％至65體積％之分子態氧， 6體積％至7〇體積％之丙烷， • 〇體積％至2〇體積％之分子態氫，及 ' 5體積％至65體積％之蒸汽。 根據本發明特別適用之部份氧化反應為丙烯（形成丙烯 酸）或丙烯駿（形成丙烯酸）之彼等部份氧化反應，其中產物 氣體混合物還包含大於或等於0體積％至4體積％(例如至0 5 體積。/〇’或至1體積d/❾，或至15體積％，或至2體積。/。，或 125528.doc -27· 200838848 至2.5體積％)之分子態氧。 原則上，液相P*中組成份的有機含量可藉由氣相層析法 測定。 當根據本發明進行部份氧化反應使產物氣體混合物中的 丙烯酸及苯甲酸轉化為液相P時，原則上可使用吸收及/或 冷凝措施。 ’ 可使用之吸收劑實例包括水、水溶液（該等水溶液可包 含（例如）0.1重量％至10重量％乙酸、0.1重量％至5重量％丙 ® 烯酸及80重量％至99.8重量％水）及/或有機（尤其為疏水性） 溶劑（例如，二苯醚、鄰苯二甲酸二苯酯及/或鄰苯二甲酸 二甲酯）。吸收前，適當地就應用觀點而言，部份氧化反 應之產物氣體混合物亦可直接及/或間接冷卻。 根據本發明合適之吸收及/或冷凝方法係（例如）在文件 DE-A 10336386、WO 01/96271、DE-A 19631645、DE-A 19501325、EP-A 982289、DE-A 19838845、WO • 02/076917、EP-A 1695954、EP-A 695736、EP-A 778225、 EP-A 1041062 、EP-A 982287 、EP-A 982288 、US 2004/0242826、EP-A 792867、EP-A 784046、EP-A ， 695736、EP-A 1125912、EP-A 1388533及在該等文件中關 、 於該主題引用之文獻中加以描述。 然而，在產物氣體混合物中之丙烯酸及苯甲酸可（例如） 亦藉由使沸點高於產物氣體混合物中之水之成份冷凝而液 化。 丙烯酸及苯甲酸轉化成液相P之吸收與冷凝轉化法如同 125528.doc -28 * 200838848 其形成液相P*之轉化法一樣，通常在包含分離内填物（以 增大父換表面積）的分離柱中進行。 亦可彼此交疊採用吸收及冷凝法。 關於上述吸收及/或冷凝方法之合適分離柱特別揭示於 DE-A 10336386、EP-A 1125912 及 US 2004/0242826 A1 中。 可用的分離内填物原則上為已知具有分離活性的所有内 • 真物換口之可恥使用盤式(諸如泡罩盤、雙流盤或閥 盤）、散堆填料（例如，拉西環（Raschig ring))或規整填料 (例如’蘇爾釆（Sulzer)填料）作為分離内填物。 在分離柱中，進行部份氧化反應之產物氣體混合物（若 適當時可預先冷卻）一般自底部以上升方式向上引導。在 吸收冷凝法中，通常使分離柱中之吸收劑自頂部向下移動 (引導）。 包含丙烯酸及苯甲酸之液相P*可自分離柱排出，就應用 • 觀點而言之適當方式為自液體柱底部或經由在適當時已先 冷卻之產物氣體混合物饋料下方的液體側取器排出。 使用至少一種熱分離方法，接著將沸點（以大氣壓為基 準）比苯甲酸及丙烯酸低之成份自液相p移除。 有利地，根據本發明，採用至少一種熱分離方法使得所 排出低沸點化合物捕捉到彼等在液相P中呈純物質且在大 氣塵下沸點小於或等於水沸點的成份。 所採用之熱分離方法特別有利於使用氣體（例如，空 氣、分子氮或其他氣體）汽提。 125528.doc -29- 200838848 為此，引導該氣體使其穿過液相p(就應用觀點而言之有 利作法為在包含分離内填物的分離柱中以逆流方式進行） 且使其中存在之低彿點成份自液相P汽提出。為了達成該 目的，宜預先加熱液相P。 適當地在低於大氣壓之操作壓力下進行汽提。 歸因於後種措施，汽提具有附加之解吸作用。應瞭解， 解吸亦可單獨用於移除低沸點化合物。Antimony, cerium oxide, cerium carbide, ceric acid salts (such as magnesium citrate or aluminum citrate) or talc. The multimetal oxide active composition of the catalyst for improving the activity of the propylene-acrylic partial oxidation reaction according to the present invention suitably contains the metal elements Mo, Fe and Bi. It has a particularly improved activity when its stoichiometry satisfies the following formula I: M〇i2Bia Feb X!c x2d X3e X4f On (I) where: X1 = nickel and/or cobalt, X = bismuth, alkali metal and/or alkaline earth Metal, X3 = rhodium, phosphorus, arsenic, boron, antimony, tin, antimony, lead and/or tungsten, χ4 = antimony, aluminum, titanium and/or antimony, a = 〇 · 5 to 5, b = 0.01 to 5, Preferably, it is 2 to 4, c=0 to 1〇, preferably 3 to 1〇, d=0 to 2, preferably 〇·〇2 to 2, 125528.doc -22- 200838848 e=0 to 8 Preferably, it is 〇 to 5, f=〇 to 10, and the value determined by the atomic valence of the element of (1) and the current: owed number. The foregoing is particularly useful when the active composition has properties as recited with respect to specific surface area and pore volume. The multimetal oxide active composition having an activity-enhancing catalyst for partial oxidation of acrylic acid-(tetra) acid according to the present invention suitably comprises metal elements Mo and V. It has a particularly improved activity when its stoichiometry satisfies the following formula II: M〇12 Va X\ x2c x3d X4e X5f X6g 〇n (n) where: X1=W, Nb, Ta, Cr and/or Ce, X2= Cu, Ni, Co, Fe, Μη and / or Zn, X3 = Sb and / or Bi, X4 = - or a variety of metal, x5 = - or a variety of soil test metals, X6 = Si, A, Ti and / or Zr , a = l to 6, b = 0.2 to 4, c = 0.5 to 18, d = 0 to 40, e = 0 to 2, f = 0 to 4, -23 - 125528.doc 200838848 g = 0 to 40, And n = a value determined by the atomic valence of the element other than oxygen in (II) and the number of occurrences. Examples which are particularly active in the active polymetal oxide (II) are those which are encompassed by the following definitions of the code of the general formula II: X1 == W, Nb and/or Cr, X2 = Cu, Ni, Co and/or Fe, X3=Sb, X4=Na and/or K, X5=Ca, Sr and/or Ba, X6=Si, A1 and/or Ti, a=l.5 to 5, b = 0.5 to 2, c = 0.5 to 3, d = 0 to 2, e = 0 to 0.2, f = 0 to 1, and n = the value determined by the valence and number of occurrences of the element other than oxygen in (II) . Advantageously, a portion of the heterogeneously catalyzed gas phase oxidation reaction of the c3 precursor compound is carried out in a tube bundle reactor. The fixed catalyst bed is placed in the reaction tube of the tube bundle reaction. A liquid heat carrier (generally gold, body or liquid) flows around the catalyst tube to remove the heat of reaction. In both cases, there is propylene or acrolein (fixed J catalyst bed installed 125528.doc -24-200838848 load can be greater than or equal to 70 L (STP) / Lh, or greater than or equal to 9 〇 L (STP) /Lh, or greater than or equal to 110 l (STP)/Lh, or greater than or equal to 130 L (STP)/L·]!, or greater than or equal to 14〇l (STP)/Lh, or greater than or equal to 160 L ( STP)/Lh, or greater than or equal to 18〇L (STP)/Lh, or greater than or equal to 240 L (STP)/Lh, or greater than or equal to 300 L (STP)/Lh. However, in general, it is less than Or equal to 6〇〇L (STp)/Lh (each load is based on the volume of the fixed catalyst bed and does not include any additional components consisting only of inert materials.) In this document, The loading of the (fixed) catalyst bed with the initial reaction gas mixture means the amount of the initial reaction gas mixture (standard liter) (L (STp)) that is directed through the 丨 liter (fixed) catalyst bed per hour; The volume of the starting reaction gas mixture under standard conditions (ie, at °° (: and 1 bar) (liters) The loading of the (fixed) catalyst bed may also be based only on one component of the starting reaction gas mixture. In this case, it is the component of the corresponding initial reaction gas mixture. The amount of this component of the liter (fixed) catalyst bed (standard liters). In this document, it is generally understood that the inert gases are generally maintained at least 95 moles/〇 without chemical changes during the partial oxidation reaction. The degree of gas is preferably at least 97 mol%, and most preferably reaches 99 mol% or more than 99 mol%. The reaction temperature in the partial oxidation of propylene-acrolein is generally 27 (rc to 450 ° C, or 280 ° C to 42 (TC, preferably 300. (: to 380. (:. Acrylonitrile - the reaction temperature in the partial oxidation of acrylic acid - generally 2 generations to 37 〇 125528.doc -25- 200838848 C, or 200 ° C to 320 ° C, preferably 220 ° C to 300 ° C. The operating pressure in the partial oxidation reaction of the present invention is generally lower than the standard pressure (for example, up to 0.5) Atmospheric pressure; inhaling the reaction gas mixture) or higher Quasi-pressure. Typically, the operating pressure will be from atmospheric pressure to 5 atmospheres, often from 1.5 atmospheres to 3.5 atmospheres. The operating pressure in the partial oxidation reaction of the present invention typically does not exceed 1 Torr. The available source of molecular oxygen required as an oxidant in the process is air or air without molecular nitrogen. The catalyst generally used in the partial oxidation of propylene (formation of acrolein) or acrolein (formation of acrylic acid) of the present invention should be used. The selectivity to form the target product (acrolein or acrylic acid) is greater than or equal to 83 mol%, often greater than or equal to 85 mol%, or greater than or equal to 88 mol%, often greater than or equal to x mol%, or greater than Or equal to 93% by mole or 93% by mole or more. A typical starting reaction gas mixture for partial oxidation of propylene (formation of acrolein) may, for example, comprise: from 5 to 12% by volume of propionium; from 2 to 15% by volume of water; greater than or equal to zero. 5% by volume to 10% by volume of propane; greater than or equal to 0.1% by volume to 5% by volume of components other than propylene, propylene, water, oxygen and nitrogen; and sufficient molecular oxygen 'where molecular oxygen and propylene are The ear ratio is 1 to 3; and the rest is a molecular nitrogen that makes up 100% by volume. Or 'initial reaction for propylene partial emulsification reaction (formation of propyl group) 125528.doc -26- 200838848 The gas mixture may comprise: 6 vol% to 10 vol% propylene, 8 vol% to 18 vol% Molecular oxygen, 6 to 3% by volume of propane, and 32 to 72% by volume of molecular nitrogen. The reaction mixture for the partial oxidation of propylene-acrolein may also contain a high volume of <h2> The initial reaction gas for the partial oxidation of acrolein (formation of acrylic acid), the mixture comprising, for example: 4% by volume to 8% by volume of acrolein, 2% by volume to 9% by volume of molecular oxygen, 〇 volume % to 3 vol% of propane, 3 vol% to 75 vol% of molecular nitrogen, and 5 vol% to 30 vol% of steam, or φ 3 to 25 vol% of acrolein, 5 vol% to 65 vol% molecular oxygen, 6 vol% to 7 vol% propane, 〇 vol% to 2 vol% molecular hydrogen, and '5 vol% to 65 vol% steam. Partial oxidation reactions which are particularly suitable in accordance with the invention are partial oxidation reactions of propylene (forming acrylic acid) or acrylonitrile (forming acrylic acid), wherein the product gas mixture further comprises greater than or equal to 0% by volume to 4% by volume (eg to 0 5 volume / 〇 ' or to 1 volume d / ❾, or to 15% by volume, or to 2 volumes / /, 125528.doc -27 · 200838848 to 2.5% by volume) of molecular oxygen. In principle, the organic content of the components in the liquid phase P* can be determined by gas chromatography. When partial oxidation is carried out in accordance with the invention to convert acrylic acid and benzoic acid in the product gas mixture to liquid phase P, absorption and/or condensation measures can in principle be used. 'Examples of absorbents that may be used include water, aqueous solutions (such aqueous solutions may include, for example, 0.1% to 10% by weight acetic acid, 0.1% to 5% by weight of acrylic acid, and 80% to 99.8% by weight of water) And/or organic (especially hydrophobic) solvents (for example, diphenyl ether, diphenyl phthalate and/or dimethyl phthalate). Prior to absorption, the product gas mixture of the partial oxidation reaction may also be cooled directly and/or indirectly, as far as the application is concerned. Suitable absorption and/or condensation methods according to the invention are, for example, in the documents DE-A 10336386, WO 01/96271, DE-A 19631645, DE-A 19501325, EP-A 982289, DE-A 19838845, WO • 02 /076917, EP-A 1695954, EP-A 695736, EP-A 778225, EP-A 1041062, EP-A 982287, EP-A 982288, US 2004/0242826, EP-A 792867, EP-A 784046, EP- A, 695736, EP-A 1125912, EP-A 1 388 533, and in the documents referred to in this document, which are incorporated herein by reference. However, the acrylic acid and benzoic acid in the product gas mixture can also be liquefied, for example, by condensing a component having a boiling point higher than that of the water in the product gas mixture. The absorption and condensation conversion method of converting acrylic acid and benzoic acid into liquid phase P is the same as that of 125528.doc -28 * 200838848 which forms a liquid phase P* conversion method, usually including separating the internal filling material (to increase the parental exchange surface area). Performed in a separation column. They can also overlap each other using absorption and condensation methods. Suitable separation columns for the above-mentioned absorption and/or condensation methods are disclosed in particular in DE-A 10 336 386, EP-A 1125912 and US 2004/0242826 A1. Useful separation fills are in principle shameless discs (such as blister trays, double flow discs or valve discs), random packings (for example, Raschig rings) (for example, blister trays, double-flow discs or valve discs), which are known to have separation activity. Raschig ring)) or structured packing (such as 'Sulzer packing') as a separate fill. In the separation column, the product gas mixture that is subjected to the partial oxidation reaction (pre-cooled if appropriate) is generally directed upward from the bottom in a rising manner. In the absorption condensation method, the absorbent in the separation column is usually moved (guided) downward from the top. The liquid phase P* comprising acrylic acid and benzoic acid can be discharged from the separation column, in a suitable manner from the point of view of the liquid side extractor from the bottom of the liquid column or via the feed of the product gas mixture which has been previously cooled first. discharge. At least one thermal separation method is employed, followed by removal of the lower boiling point (at atmospheric pressure) than the benzoic acid and acrylic acid components from the liquid phase p. Advantageously, in accordance with the present invention, at least one thermal separation process is employed to cause the discharged low boiling point compounds to capture components which are pure in the liquid phase P and which have a boiling point less than or equal to the boiling point of water under atmospheric dust. The thermal separation process employed is particularly advantageous for stripping gases (e.g., air, molecular nitrogen, or other gases). 125528.doc -29- 200838848 For this purpose, the gas is directed through the liquid phase p (advantageous from the point of view of application in a countercurrent manner in a separation column comprising separated internal packing) and is present therein The low-fool point component is stripped from the liquid phase P. In order to achieve this, it is preferred to heat the liquid phase P in advance. Stripping is suitably carried out at an operating pressure below atmospheric pressure. Due to the latter measures, stripping has an additional desorption effect. It will be appreciated that desorption can also be used alone to remove low boiling compounds.
替代汽提及/或解吸，或者另外在其後，可進行精餾法 移除低沸點化合物。尤其當將分離線固定在水沸點時，適 合進行精餾法，使至少一部份低沸點化合物在共沸精餾法 中移除。此時合適之共沸劑實例包括庚烷、二曱基環己 烷、乙基環己烷、甲苯、乙苯、辛烷、氯苯、二甲苯或其 混合物（例如，含有60重量％甲苯及4〇重量％庚烷之彼等混 合物）。可使用之替代性共沸劑亦為甲基異丁基酮或乙酸 異丙酯。The alternative steam is mentioned/or desorbed, or otherwise, the rectification process can be carried out to remove low boiling compounds. Particularly when the separation line is fixed at the boiling point of water, it is suitable to carry out a rectification method to remove at least a part of the low boiling point compound in the azeotropic distillation method. Examples of suitable entraining agents at this time include heptane, dimercaptocyclohexane, ethylcyclohexane, toluene, ethylbenzene, octane, chlorobenzene, xylene or a mixture thereof (for example, containing 60% by weight of toluene and 4〇% by weight of the mixture of heptane). Alternative azeotropes which may be used are also methyl isobutyl ketone or isopropyl acetate.
其他合適共濟劑揭示在Us 2⑽·2428%、Ep A 778255、ΕΡ·Α 695736及該等文件中所引用之先前技術 中。通常上述精顧同樣宜在低於大氣壓之操作麼力下進 行。應瞭解’上述各熱分離方法可單獨使用或與所提及之 一種或多種其他熱分離方法組合使用。 因為根據本發明僅為達成移除低沸點化合物之目的而有 :地：用：分離方法’故本發明製程之另一項優點亦為不 = 物形成度特別低及/或對聚合抑制劑的需求 125528.doc -30- 200838848 ^而，應瞭解該文件中詳述之所有方法步驟均採用聚合 抑制法進行。該製程可如所引用之先前技術中所述。在所 有可用丙烯酸製程穩定劑中，尤為傑出者為二苯m嗟 嘻（PTZ)、4-經基_2,2,6,6_四甲基哌咬i•氧基（4·肌 TEMPO)及對甲氧基苯_EHQ)，該等穩定劑可為待根據 本發明處理之混合物（尤其為液相）的—部分，其分別呈單 獨或成對或以三元混合物形[通常包含丙稀酸之液相中Other suitable mutual agents are disclosed in Us 2 (10) 2428%, Ep A 778255, ΕΡ Α 695736, and the prior art cited in these documents. Usually, the above-mentioned intent should also be carried out under sub-atmospheric operation. It will be appreciated that each of the above thermal separation methods can be used alone or in combination with one or more of the other thermal separation methods mentioned. Since, according to the present invention, only for the purpose of achieving the removal of low-boiling compounds, there is a ground: using: a separation method, so another advantage of the process of the present invention is also that the degree of formation is particularly low and/or for polymerization inhibitors. Requirements 125528.doc -30- 200838848 ^ However, it should be understood that all method steps detailed in this document are carried out using polymerization inhibition. The process can be as described in the prior art cited. Among all the available acrylic process stabilizers, the most outstanding ones are diphenylm嗟嘻 (PTZ), 4-ionyl-2,2,6,6-tetramethylpiperidine (4·muscle TEMPO). And p-methoxybenzene_EHQ), which may be part of a mixture (particularly a liquid phase) to be treated according to the invention, which are individually or in pairs or in the form of a ternary mixture [usually comprising C Dilute acid in the liquid phase
的聚合抑制劑之總量占基於其中存在之丙烯酸總量之 0.001重量％至2重量％。 在進行所述之低沸點化合物移除法後，一般殘留之物質 為包含至少80重量％之丙烯酸及占丙烯酸含量至少重量 %。之苯甲酸的液相ρ*β以液相P*中之丙烯酸為基準計，宜 包含按重量計至少50 ppm或至少〇 2%或〇 2%至15%的水。 由於當包含丙烯酸之液相單獨殘留0寺，液相中會形成不 期望之丙埽酸寡聚物（麥T(Michael)加合物），⑻盡可能在 獲得液相P*後立即採用本發明之結晶移除法。同樣積聚在 母液中之丙烯酸寡聚物的熱解離仙使得其中存在之丙婦 酸得以回收且再循環至詩獲得液相pA/或p*之熱分離方 法中之一者。 一般而言，繼根據本發明之方法後，熔融丙烯酸晶體且 由游離自由基聚合為聚合物。上述聚合物經常為超吸收性 聚丙烯酸酯。 實例 使用具有2公升容量之攪拌槽。該攪拌槽之幾何形狀為 125528.doc •31· 200838848 圓柱形，其中内徑為110 mm。攪拌槽係由玻璃製成。然 而，攪拌槽之底部係由不鏽鋼製成夾套形式。不繡鋼壁厚 度為2 mm。兩壁之間隔大致為i cm。由3〇重量％水、牝重 ϊ %曱醇及30重量％乙二醇組成之混合物作為冷卻介質流 經兩壁之間的空間（至少75 L/h)。 藉由雙槳葉式攪拌器（槳葉高度為5〇 mm，直徑為” mm，且旋轉速率為500 rpm)攪拌攪拌槽之内容物。 在所有實驗中，將攪拌槽填充1500 §至165〇 g冰丙烯 酸，其中丙烯酸含量大於或等於99 5重量％且已摻雜有不 同含量之苯甲酸（其溫度為25。〇的。其水含量為按重量計 148 ppm。此外，已藉由含量為按重量計大致25〇_27〇卯瓜 之啡噻嗪（ρτζ)抑制冰丙烯酸之聚合。以15尺化至的κ/匕之 冷卻速率使冷卻介質之溫度（分別自丨丨它之起始溫度進行） 連續下降。 在各狀況下，一旦沈積在槽底部之晶體層具有大致1〇 mm之層厚度d的質量μ時，即中斷結晶過程。安裝攪拌槽 使其可旋轉。在中斷結晶過程下，打開攪拌槽頂部，以便 使殘留母液（母酸)流出。隨後，分別分析已流出之母液及 所沈積晶體的苯甲酸含量，且自分析結果計算特 數Αβζα。 开 相耗係 下表中顯示所獲得之結果。該表另外顯示晶體生長速率 w (mm/min)及冷卻時間 t (min)。 2006年10月19曰申請之美國臨時專利申請 60/852674號係以文獻引用的方式併入本專利申請案弟 125528.doc -32· 200838848 上述教示可能出現許多不同於本發明之改變及偏差。因 此可在附錄之申請專利範圍之範疇内，以不同於本文特定 描述之方式進行本發明。The total amount of the polymerization inhibitor is from 0.001% by weight to 2% by weight based on the total amount of the acrylic acid present therein. After the low boiling point compound removal process is carried out, the generally remaining material comprises at least 80% by weight of acrylic acid and at least % by weight based on the acrylic acid content. The liquid phase ρ*β of the benzoic acid preferably contains at least 50 ppm by weight or at least 〇 2% or 〇 2% to 15% by weight based on the acrylic acid in the liquid phase P*. Since the propionate oligomer (Mt. T (Michael) adduct) is formed in the liquid phase when the liquid phase containing the acrylic acid remains alone, (8) the sample is used as soon as possible after obtaining the liquid phase P*. The crystal removal method of the invention. The thermal dissociation of the acrylic oligomer which also accumulates in the mother liquor allows one of the glycerin which is present therein to be recovered and recycled to one of the thermal separation methods for obtaining the liquid phase pA/ or p*. In general, following the process according to the invention, the acrylic acid crystals are melted and polymerized from free radicals into a polymer. The above polymers are often superabsorbent polyacrylates. Example A stirred tank having a capacity of 2 liters was used. The geometry of the agitation tank is 125528.doc • 31· 200838848 cylindrical with an inner diameter of 110 mm. The agitation tank is made of glass. However, the bottom of the agitation tank is in the form of a jacket made of stainless steel. The thickness of the stainless steel wall is 2 mm. The spacing between the two walls is approximately i cm. A mixture of 3% by weight of water, 牝% by weight of sterol and 30% by weight of ethylene glycol flows as a cooling medium through the space between the walls (at least 75 L/h). Stir the contents of the stirred tank with a double paddle stirrer (blade height 5 〇 mm, diameter "mm" and rotation rate 500 rpm). In all experiments, the agitation tank was filled with 1500 § to 165 〇 g glacial acrylic acid, wherein the acrylic acid content is greater than or equal to 99.5% by weight and has been doped with different contents of benzoic acid (the temperature of which is 25. 〇. The water content is 148 ppm by weight. In addition, the content has been About 25 〇 〇卯 27 〇卯 之 之 啡 噻 噻 噻 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制 抑制The temperature is continuously decreased. In each case, once the crystal layer deposited at the bottom of the groove has a mass μ of a layer thickness d of approximately 1 mm, the crystallization process is interrupted. The stirring tank is installed to make it rotatable. Next, the top of the agitation tank is opened to allow the residual mother liquor (mother acid) to flow out. Subsequently, the benzoic acid content of the mother liquor and the deposited crystals which have flowed out are separately analyzed, and the special number Αβζα is calculated from the analysis result. The open phase consumption is in the following table. Display The results obtained are shown in the table. The table further shows the crystal growth rate w (mm/min) and the cooling time t (min). The US Provisional Patent Application No. 60/852674, filed on October 19, 2006, is hereby incorporated by reference. </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> <RTIgt; .
125528.doc -33 - 200838848125528.doc -33 - 200838848
ABZA 54.1 31.5 30.3 T (min) 00 in m v〇 m W (mm/min) 0.152 1 0.206 0.300 ^ 3 161.2 1 89.9 120.7 d (mm) 12.9 (N 10.8 冷卻速率 (K/h) § PTZ之 重量％ 270 270 270 J 苯曱酸含量 (重量％。） »rj 樣品A 樣品B 樣品C f-ϊ迴鵪w V碱傘瑞¾^窩¢^齧β,窻裝肊4 w I槳齧费肊_ Φ了 K 要。V鵪，#坺« 》03衾^槽栖4耷餘^杯蟑111:锪蕖¥1叫啣，锪&-埏，餵肊费镏费^》鉍#毽裝肊_娄 125528.doc -34-ABZA 54.1 31.5 30.3 T (min) 00 in mv〇m W (mm/min) 0.152 1 0.206 0.300 ^ 3 161.2 1 89.9 120.7 d (mm) 12.9 (N 10.8 Cooling rate (K/h) § PTZ weight % 270 270 270 J benzoic acid content (% by weight.) »rj sample A sample B sample C f-ϊ回鹌 w V alkali umbrella 瑞 3⁄4^ nest ¢ ^ β β, 窻 肊 4 w I paddle 肊 肊 Φ K 要,V坺,#坺« 》03衾^槽栖4耷余^杯蟑111:锪蕖¥1 is called title,锪&-埏, feeding fee镏^^铋#毽装肊_娄125528.doc -34-
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| DE102006049939A DE102006049939A1 (en) | 2006-10-19 | 2006-10-19 | Separating acrylic acid from a gas-phase oxidation product gas comprises separating acrylic acid from benzoic acid by crystallization |
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| DE19833049A1 (en) * | 1998-07-22 | 2000-01-27 | Basf Ag | Acrylic acid production by gas-phase oxidation of 3C feedstock, involves work-up by condensation and vacuum-crystallization, recycling mother liquor and evaporated liquid to the condensation stage |
| DE19926082A1 (en) * | 1999-06-08 | 2000-12-14 | Basf Ag | Process for the purification and production of acrylic acid or methacrylic acid |
| DE10211686A1 (en) * | 2002-03-15 | 2003-10-02 | Stockhausen Chem Fab Gmbh | (Meth) acrylic acid crystal and process for the production and purification of aqueous (meth) acrylic acid |
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