201237029 六、發明說明： 【發明所屬之技術領域】 本發明係關於純化碳酸：㈣之方法，包括無環碳酸二 烧醋類（例如碳酸二乙醋）及環狀碳酸二烧醋類，其中該等 燒基基團係連接在一起以形成環，亦即碳酸伸院醋類，例 _ 如碳酸伸乙酯。 【先前技術】 碳酸伸烷酯（例如碳酸伸乙酯）係藉由與烷醇反應生產無 環碳酸二烷酯及單烷二醇之重要的原材料β例如，碳酸伸 乙酯及乙醇可反應以形成碳酸二乙醋及單乙二醇。 而’無環碳酸二烷酯（諸如碳酸二曱酯或上述碳酸二乙 酯）係重要的化學製品《其可（例如）用作藉由與苯酚反應生 產碳酸二苯酯之原材料。例如，碳酸二曱酯係廣泛描述於 文獻（參見’例如D. Delledonne等人，Appl. Catal. Α，2001， 221，241-251)中用於一系列應用，諸如碳酸二苯酯製造（上 面已述及）’異氰酸酯製造（經由胺甲酸酯中間體），用作甲 基化試劑’在多種應用中用作溶劑及在液態燃料中用作含 氧物#合分子。 • 上述碳酸二苯酯係商業上生產聚碳酸酯之重要的原材 、 料。被酸一本S曰可與二經基芳香化合物（例如雙紛A ’其為 4,4’-(丙-2-亞基）二酚）聚合成聚碳酸酯。該碳酸二苯酯原材 料在其與該二羥基芳香化合物反應之前具有充分純度係重 要的。該純度可藉由確保在先前步驟中用以製造碳酸二苯 酯的原材料（例如上述碳酸伸乙酯及碳酸二乙酯）具有充分 160744.doc 201237029 純度而達成。 此外，確保上述碳酸二烷基酯原材料具有充分純度亦使 得副反應更少，並因此得到所討論之反應的更高產率及/ 或選擇性。 碳酸二烷酯之製備，即包括無環碳酸二烷酯類及碳酸伸 烧酯類，不管採用的方法’不可避免地含有變化量的多種 污染化合物。此等雜質應在使用碳酸二烧酯進行後繼步驟 之前盡可能多的移除，以阻止彼等雜質對此進一步反應之 任何干擾。 例如，如於EP 0633241中揭示，碳酸二苯酯中污染物之 存在可影響與雙酚A之聚合速率。所得的聚合物產物可具 有低固有黏度。此外，此等污染物之存在亦可影響該聚碳 酸酯聚合物之顏色。 可見於此等碳酸二烷酯製備的示例性雜質係金屬離子， 其可源自於所討論的製備碳酸二烷醋中使用的該或該等催 化劑。此等金屬雜f之實例係欽陽離子、鐵陽離子、辞陽 離子、鉻陽離子等。 另-類雜質係含有非金屬之有機及無機污染物，諸如碳 及/或齒素（諸如溴、氯及蛾），其亦可源自於所討論的製備 碳酸二烷酯中使用的該或該等催化劑，或源自於所使用的 反應劑之-。亦含㈣素之有機磷污染物之實例係用作轉 酉曰化反應催化劑的_化四院基鱗，諸如（例如）於鄭 _湖113中揭示的漠化四貌基鱗，其可用於生產 院5曰，例如碳酸伸乙酯。 160744.doc 201237029 另一類雜質包含一系列識別稱為「發色體」之化合物。 此為一類涵括可含有如上討論的金屬及/或鹵化物且其影 響將自該碳酸二烷酯所產生之產物顏色的化合物之污染 物。此外，US 20040225162，其揭示内容係以引用之方式 併入本文’提及用術語「顏色」及「發色體」意指可見顏 色之存在可藉由使用在可見光範圍内的分光計，使用大約 400-800 nm之波長，並藉由與純水比較而量化。 例如，與移除有機碳酸（更特定（環狀）碳酸伸烷基酯）中 之顏色相關的WO 200005228揭示以下内容。有機碳酸㊉ 之變色可由在合成該有機碳酸酯期間形成有顏色的雜質或 副產物而引起。有機碳酸酯中顏色之存在或不存在亦可反 映該碳酸酯所經歷的精煉或純化程度。或者，變色可由在 儲藏或處理該碳酸酯期間獲得的污染物而引起。有機碳酸 酯中變色不利地降低了產物價值。例如以上已討論的當需 要具有充分純度之產物時，出於美學原因或出於其他原因 希望減少顏色。 用 如以上出現的，在該項技術中需要簡單及有效分離法， 於純化受污染之含碳酸二烷酿之流，即，包括無環碳酸 二烷酯及碳酸伸烷酯之該碳酸二烷酯類。 【發明内容】 本發明之一目的是提供純化滿足該需要之碳酸二烷酯之 方法。該目的係藉由使用膜（其係非多孔性膜（無孔）或夺米 過濾'膜（具有平均尺寸最大1〇 nm之孔）而達成。此非多孔 性及奈米過濾膜係在該項技術中常稱作緻密膜。 160744.doc 201237029 【實施方式】 因此，本發明之方法係藉由膜分離純化碳酸二烷酯之方 法’其中使用的膜具有平均孔尺寸自〇至10 nm。該碳酸二 烧ϊ旨係式RiCHCCOOR2，其中心及尺2係烷基，其等烷基並 未連接在一起形成環’或該碳酸二烷酯係式ri〇(c〇)〇R2 之環狀碳酸酯’其中心及!^係連接在一起形成環。 亦即’在本發明書内，該術語「碳酸二烷酯」涵括以下 二者（i)無環碳酸二烷酯（即，其中烷基未連接在一起形成 環）及（ii)環狀碳酸二烷酯，其中烷基連接在一起形成環， 亦即碳酸伸烧醋》 在本發明肀，對於在以上（i)下提及的無環碳酸二烷酯， 該專炫基R1及R_2可相同或不同，較佳係相同。此外，較佳 地，在此無環碳酸二烷酯中的烷基R!及R2(其等基團可為 直鏈、支鏈及/或環狀彡係匚“烷基’更佳地係Cl_6烷基，諸 如異丙基、乙基及曱基，適宜地乙基。較佳地，該無環碳 酸二烧醋係碳酸二甲醋或碳酸二乙醋，更佳地係碳酸二乙 酯。 在本發明中，對於以上（Π)下述及的環碳酸二烧酯，亦 即碳酸伸烷酯，該碳酸伸烷酯可為C2-8烯烴之1，2-碳酸 酯’較佳C2_6烯烴，諸如乙烯、丙烯、丁二烯及環己烯。 較佳地’該碳酸伸院酯係碳酸伸乙酯或碳酸伸丙酯，更佳 地碳酸伸乙醋。 在藉由膜分離純化碳酸二烷酯之本發明方法中，含有碳 酸二烷酯及污染物之液態進料係藉由膜分離成含有碳酸二 160744.doc 201237029 烷酯且無污染物或污染物之濃度係低於進料中污染物濃度 之液態滲透物，與含有碳酸二烷酯及污染物的濃度高於進 料中污染物濃度之液態滯留物。亦即，在本發明方法中， 該進料及渗透物皆為液相。因此，無相變化。 一般而言，當加熱由兩種或更多種組分組成之液體時， 起泡點係形成第一個蒸汽泡的點。對於單一組分混合物， 起泡點與沸點相同。在該分離技術中，其中「滲透蒸發」 係使用膜施加’在該膜之滲透物侧上的壓力及温度係使得 該滲透物係高於其起泡點’而引起該滲透物成為蒸汽。 申請人已發現當使用非多孔性或奈米過濾膜時，在此用 於純化碳酸二烷酯之方法中獲得良好的分離結果。 非多孔性或奈米過渡膜在純化烴類中之應用一般係描述 於WO 2001060771中（以Shell之名義申請）。此文件揭示了 純化受污染之液態烴產物之方法，其中該產物流係與非多 孔性或奈米過濾膜接觸且該純化的產物流係作為滲透物回 收。儘管對於W02001060771中液態烴產物之性質無特定 限制，該等特定提及的產物典型地係工業上生產的含有可 聚合烯鍵之化學產物流。該等產物可包括一或多個雜原 子，且液態烴產物之命名的實例包括環戊二稀、二環戊二 烯' 1，3-環己二烯、環己烯、苯乙烯、異戊二烯、丁二 烯、順-1,3-戊二烯、反-1，3-戊二烯、苯、曱苯、二甲苯、 乙烯及丙稀。含有雜原子之命名的液態烴產物係丙烯酸甲 醋、丙稀酸乙醋及曱基丙稀酸甲醋。然而，在WO 2001060771中未提及純化受污染之碳酸二烷酯流。 160744.doc 201237029 待於本發明中使用的非多孔性或奈米過濾膜可為陶瓷或 聚合型。該使用的膜可為疏水的或親水的。 適宜之非多孔性及奈米過濾膜之實例係反滲透型臈。非 多孔性及奈米過濾膜應與總是多孔的超過濾膜區分。該等 超過濾膜具有平均孔尺寸大於1〇 nm至高約800 nm。使用 的多孔的奈米過濾膜’其等具有平均膜孔尺寸最大1〇 nm(奈米多孔的膜）。其中此奈米過濾或奈米多孔的膜係依 據本發明使用’該平均膜孔尺寸係適當地小於1〇 nm，較 佳地最大8 nm，更佳地最大7 nm，更佳地最大6 nm，更佳 地最大5 nm，更佳地小於5 nm，更佳地最大4 nm，更佳地 最大3 nm，更佳地最大2 nm，更佳地最大丨nm，更佳地最 大〇.7nm，更佳地最大〇5nm及最佳地最大〇3nm。 超過濾係壓力差驅動的膜過濾技術，其中使用的多孔膜 具有平均孔尺寸大於丨〇 nm。如上述使用超過濾膜之缺點 之為該等膜在操作期間積垢（膜孔阻塞或堵塞）且最終不 知不出於清潔之目的從操作中取出或若該膜積垢不可逆則 不得不替換。此遲早將嚴重降低該分離之效率。 測定膜用於自碳酸二烷酯分離污染物X之適用性之一種 方式係藉由計算排斥因子，如下： 排斥因子=(l-([X]P/[X]f)) 其中[X]P係滲透物中污染物X之濃度且[x]f係進料中污染物 X之廛度。其中在本說明書令提及排斥污染物，意指按上 述方式定義的排斥因子。 在其中排斥因子大於0之所有情況下，該污染物自該待 160744.doc 201237029 純化之化合物的分離已發生。亦即，比穿過該膜的污染 物’相對更多的污染物藉由該膜保留。在此情況下，如本 發明之目的，提高了該穿過的碳酸二烷酯之純度。然而， 較佳該排斥因子係大於0.2，更佳地大於0.4，甚至更佳地 大於0·6 ’仍甚至更佳地大於〇.8，且最佳地大於〇 9。在膜 分離中排斥因子之一般討論可見於由Prof. Marcel Mulder 斤者的 Basic Principles of Membrane Technology」 (ISBN 0-7923-4248-8)。 如上述’該待用於本發明的非多孔性或奈米過濾膜可為 陶瓷膜。該陶瓷型膜之優點係其等不需要膨脹以在最佳條 件下工作。陶瓷型之實例係中孔氧化鈦、中孔γ-氧化鋁、 中孔氧化錯及中孔氧化石夕。 然而，在本發明之較佳實施例中，該非多孔性或奈米過 濾膜係聚合膜。此聚合膜較佳係交聯的以提供必須的網絡 ;避免該膜一旦與碳酸二院酯及任何用以溶解該碳酸二 烧酉曰的岭劑接觸時溶解。—般而言，可以數種方式影響該 交聯’例如藉由與交聯劑反應（化學交聯）及/或藉由輕照。 ,也°亥膜層具有矽氧烷結構，其如（例如）於W0 199627430中描述的藉由輻照交聯。 適宜的， 田别可獲得的交聯非多孔性或奈米過濾膜之實201237029 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method for purifying carbonic acid: (4), comprising acyclic carbonic acid decocted vinegar (for example, ethylene carbonate) and cyclic carbonated vinegar, wherein The other groups are bonded together to form a ring, that is, a carbonated vinegar, such as ethyl carbonate. [Prior Art] An alkylene carbonate (e.g., ethyl acetate) is an important raw material for producing an acyclic aminate and a monoalkylene glycol by reaction with an alkanol. For example, ethyl carbonate and ethanol can be reacted. Formed diethyl carbonate and monoethylene glycol. Further, the 'acyclic dialkyl carbonate (such as dinonyl carbonate or the above diethyl carbonate) is an important chemical which can be used, for example, as a raw material for producing diphenyl carbonate by reacting with phenol. For example, dinonyl carbonate is widely described in the literature (see 'For example D. Delledonne et al, Appl. Catal. Α, 2001, 221, 241-251) for a range of applications, such as the manufacture of diphenyl carbonate (above It has been mentioned that 'isocyanate production (via urethane intermediates), used as a methylating agent' as a solvent in various applications and as an oxygenate # molecule in liquid fuels. • The above diphenyl carbonate is an important raw material and material for the commercial production of polycarbonate. It can be polymerized into a polycarbonate by an acid-based sulfonium compound with a di-based aromatic compound (for example, bis-A' which is 4,4'-(prop-2-ylidene)diphenol. The diphenyl carbonate raw material is of sufficient purity before it is reacted with the dihydroxy aromatic compound. This purity can be achieved by ensuring that the raw materials used to produce the diphenyl carbonate in the previous step (e.g., the above-described ethyl carbonate and diethyl carbonate) have a purity of 160744.doc 201237029. In addition, ensuring that the above dialkyl carbonate raw materials are of sufficient purity also results in less side reactions and thus higher yields and/or selectivities of the reactions in question. The preparation of dialkyl carbonates, i.e., acyclic aminates and carbonic acid esters, inevitably contain varying amounts of various contaminating compounds, regardless of the method employed. These impurities should be removed as much as possible before the subsequent steps using dicarbonate to prevent any interference with their impurities in this further reaction. For example, as disclosed in EP 0 633 241, the presence of contaminants in diphenyl carbonate can affect the rate of polymerization with bisphenol A. The resulting polymer product can have a low intrinsic viscosity. In addition, the presence of such contaminants can also affect the color of the polycarbonate polymer. Exemplary impurity metal ions prepared from such dialkyl carbonates can be found, which can be derived from the catalyst or catalysts used in the preparation of the dialkyl carbonate discussed. Examples of such metal impurities f are cations, iron cations, cations, chromium cations and the like. Other types of impurities contain non-metallic organic and inorganic contaminants such as carbon and/or dentate (such as bromine, chlorine and moth), which may also be derived from the use of the dialkyl carbonate in question as discussed. These catalysts, or derived from the reactants used. An example of an organophosphorus contaminant also containing (four) is used as a catalyst for the conversion reaction, such as the desertification quadrature scale disclosed in Zheng Yihu 113, which can be used for 5 生产 in the production institute, such as ethyl carbonate. 160744.doc 201237029 Another type of impurity contains a series of compounds that are known as "chromophores". This is a class of contaminants comprising a compound which may contain the metal and/or halide as discussed above and which affects the color of the product to be produced from the dialkyl carbonate. In addition, US 20040225162, the disclosure of which is incorporated herein by reference in its entirety """"color" and "chromophore" means that the presence of visible color can be achieved by using a spectrometer in the visible range. The wavelength of 400-800 nm is quantified by comparison with pure water. For example, WO 200005228, which relates to the removal of color in organic carbonic acid (more specific (cyclic) alkylene carbonate), discloses the following. The discoloration of the organic carbonic acid can be caused by the formation of colored impurities or by-products during the synthesis of the organic carbonate. The presence or absence of color in the organic carbonate also reflects the degree of refining or purification experienced by the carbonate. Alternatively, discoloration may result from contaminants obtained during storage or handling of the carbonate. Discoloration in organic carbonates undesirably reduces product value. For example, when it is desired to have a product of sufficient purity, it is desirable to reduce color for aesthetic reasons or for other reasons. As appears above, there is a need in the art for a simple and efficient separation process for purifying a contaminated dialkyl carbonate-containing stream, i.e., the dialkyl carbonate comprising acyclic alkane carbonate and alkylene carbonate. Esters. SUMMARY OF THE INVENTION One object of the present invention is to provide a method of purifying a dialkyl carbonate which satisfies this need. This object is achieved by using a membrane which is a non-porous membrane (non-porous membrane or a rice-filtered membrane) having pores having an average size of at most 1 〇 nm. This non-porous and nanofiltration membrane is The technique is often referred to as a dense film. 160744.doc 201237029 [Embodiment] Therefore, the method of the present invention is a method for separating and purifying dialkyl carbonate by membrane separation, wherein the membrane used has an average pore size from 〇 to 10 nm. Dicarbocarbonate is a type of RiCHCCOOR2, the center of which is alkyl and its alkyl group is not linked to form a ring or a cyclic carbonate of the dialkyl carbonate system ri〇(c〇)〇R2 The ester 'the center and the ^^ are joined together to form a ring. That is, in the present invention, the term "dialkyl carbonate" encompasses both (i) acyclic aminate (ie, wherein the alkane The bases are not joined together to form a ring) and (ii) a cyclic dialkyl carbonate in which the alkyl groups are joined together to form a ring, that is, a carbonated vinegar. In the present invention, for the above mentioned in (i) above Acyclic adicarbonate, the singular groups R1 and R_2 may be the same or different, preferably the same Further, preferably, the alkyl groups R! and R2 in the acyclic dialkyl carbonate may be linear, branched and/or cyclic oxime "alkyl" more preferably. Is a Cl_6 alkyl group, such as isopropyl, ethyl and decyl, suitably ethyl. Preferably, the acyclic carbonic acid bicarbonate is dimethyl carbonate or diethyl carbonate, more preferably diethylene carbonate. In the present invention, for the above-mentioned (di) or dialkyl carbonate, that is, an alkylene carbonate, the alkylene carbonate may be a 1,2-carbonate of a C2-8 olefin. C2_6 olefin, such as ethylene, propylene, butadiene and cyclohexene. Preferably, the carbonic acid ester is an ethyl carbonate or propylene carbonate, more preferably ethylene carbonate. It is purified by membrane separation. In the process of the present invention, the liquid feed containing dialkyl carbonate and contaminants is separated by a membrane into a carbonate containing carbonic acid 160744.doc 201237029 and the concentration of no contaminants or contaminants is lower than The liquid permeate of the contaminant concentration in the feed, and the liquid stagnation of the concentration containing the dialkyl carbonate and the contaminant higher than the concentration of the contaminant in the feed That is, in the process of the present invention, both the feed and the permeate are in the liquid phase. Therefore, there is no phase change. In general, when heating a liquid composed of two or more components, the bubble point Is the point at which the first vapor bubble is formed. For a single component mixture, the bubble point is the same as the boiling point. In this separation technique, wherein "pervaporation" is the use of a membrane to apply 'pressure on the permeate side of the membrane and The temperature system causes the permeate system to be above its bubble point' to cause the permeate to become vapor. Applicants have discovered that when a non-porous or nanofiltration membrane is used, in the process for purifying dialkyl carbonate Good separation results are obtained. The use of non-porous or nano-transition membranes in the purification of hydrocarbons is generally described in WO 2001060771 (filed in the name of Shell). This document discloses a method of purifying a contaminated liquid hydrocarbon product wherein the product stream is contacted with a non-porous or nanofiltration membrane and the purified product stream is recovered as a permeate. Although there is no particular restriction on the nature of the liquid hydrocarbon product in WO2001060771, the specifically mentioned products are typically industrially produced chemical product streams containing polymerizable ethylenic bonds. The products may include one or more heteroatoms, and examples of the nomenclature of the liquid hydrocarbon product include cyclopentadiene, dicyclopentadiene '1,3-cyclohexadiene, cyclohexene, styrene, isoprene Diene, butadiene, cis-1,3-pentadiene, trans-1,3-pentadiene, benzene, toluene, xylene, ethylene and propylene. The liquid hydrocarbon products containing the nomenclature of the hetero atom are acrylic acid acetonate, acetoacetic acid vinegar, and mercapto acrylic acid methyl vinegar. However, purification of the contaminated dialkyl carbonate stream is not mentioned in WO 2001060771. 160744.doc 201237029 The non-porous or nanofiltration membrane to be used in the present invention may be of a ceramic or polymeric type. The membrane used can be hydrophobic or hydrophilic. An example of a suitable non-porous and nanofiltration membrane is a reverse osmosis type. Non-porous and nanofiltration membranes should be distinguished from ultra-filtration membranes that are always porous. The ultrafiltration membranes have an average pore size greater than 1 〇 nm to a height of about 800 nm. The porous nanofiltration membrane used was such that it had an average membrane pore size of at most 1 〇 nm (nano porous membrane). Wherein the nanofiltration or nanoporous membrane system is used according to the invention, the average membrane pore size is suitably less than 1 〇 nm, preferably at most 8 nm, more preferably at most 7 nm, more preferably at most 6 nm, More preferably, the maximum is 5 nm, more preferably less than 5 nm, more preferably at most 4 nm, more preferably at most 3 nm, more preferably at most 2 nm, more preferably at most 丨nm, more preferably at most 〇.7 nm, More preferably, the maximum is 〇5 nm and the optimum is 〇3 nm. Ultrafiltration is a pressure differential driven membrane filtration technique in which the porous membrane has an average pore size greater than 丨〇 nm. A disadvantage of using ultrafiltration membranes as described above is that the membranes foul during operation (membrane pores are blocked or clogged) and are ultimately not known to be removed from the operation for cleaning purposes or have to be replaced if the membrane fouling is irreversible. This sooner or later will severely reduce the efficiency of this separation. One way to determine the suitability of a membrane for the separation of contaminant X from dialkyl carbonate is by calculating the rejection factor as follows: Repulsive factor = (l-([X]P/[X]f)) where [X] The concentration of contaminant X in the P-series and [x]f is the concentration of contaminant X in the feed. Wherein reference is made to the exclusion of contaminants in this specification, which means an exclusion factor as defined above. In all cases where the rejection factor is greater than zero, the separation of the contaminant from the compound to be purified by 160744.doc 201237029 has occurred. That is, relatively more contaminants than the contaminants passing through the membrane are retained by the membrane. In this case, as the object of the present invention, the purity of the passed dialkyl carbonate is improved. Preferably, however, the rejection factor is greater than 0.2, more preferably greater than 0.4, even more preferably greater than 0.6 Å, still more preferably greater than 〇8, and most preferably greater than 〇9. A general discussion of rejection factors in membrane separation can be found in the Basic Principles of Membrane Technology by Prof. Marcel Mulder (ISBN 0-7923-4248-8). The non-porous or nanofiltration membrane to be used in the present invention as described above may be a ceramic membrane. The advantage of this ceramic type film is that it does not require expansion to operate under optimum conditions. Examples of ceramic types are mesoporous titanium oxide, mesoporous gamma-alumina, mesoporous oxidation and mesoporous oxide. However, in a preferred embodiment of the invention, the non-porous or nanofiltration membrane is a polymeric membrane. Preferably, the polymeric film is crosslinked to provide the necessary network; the film is prevented from dissolving upon contact with the bismuth carbonate and any mulch used to dissolve the bismuth carbonate. In general, the crosslinking can be effected in several ways, e.g. by reaction with a crosslinking agent (chemical crosslinking) and/or by light exposure. Also, the film layer has a decane structure which is crosslinked by irradiation as described, for example, in WO 199627430. Suitable, cross-linking non-porous or nanofiltration membranes available in the field
典型上， 該等使用的聚⑪氧院含有重複單元备〇，其 兀-Si-0_ ^ 其 知，例如於US 5102551中描述的。 I60744.doc 201237029 中矽原子帶有氫或烴基基團。較佳地，該等重複單元係式 (I) -Si(R)(R')-〇. ⑴ 其中R及R’可相同或相異且表示氫或選自於由烷基、芳烷 基、環烷基、芳基及烷芳基組成之群的烴基基團。較佳 地，基團R及R，之至少一者係烷基基團，且最佳兩基團皆 為烷基基團，更尤其是甲基基團。該烷基基團亦可為 3,3,3-二氟丙基基團。極適宜本發明目的之聚矽氧烷係（_ OH或-NH2末端）聚二甲基矽氧烷及聚辛基甲基矽氧烷。因 此，較佳地，該聚矽氧烷係交聯的。通過聚矽氧烷之反應 性末端-OH或-NH2基團可影響該交聯。該等較佳的聚矽氧 燒膜係交聯的彈性聚石夕氧院膜。 適宜之交聯彈性聚矽氧烷膜之實例係廣泛描述於上述 US 5102551中。因此，適宜的膜係由例如前述的聚矽氧烷 聚合物組成，該聚矽氧烷聚合物具有分子重量55〇至 15〇,〇〇〇,較佳地550至4200(在交聯之前），其作為交聯劑 與⑴聚異氰酸酯，或（ii)聚（碳醯氣）或（iii)R4aSi(A)a交聯， 其中八為·011、_NH2、-〇R或-OOCR，a為2、3或4，且R為 氩、烧基、芳基、環院基、烧芳基或芳烧基。關於適宜之 聚石夕氧院之進一步細節可見於US 5102551。 出於本發明之目的，該較佳的非多孔性膜係聚二甲基矽 氧烧或聚辛基甲基石夕氧烧膜，其較佳係交聯的。亦可使用 其他的橡膠非多孔性膜。一般而言，橡膠膜可定義為具有 種聚合物或聚合物之組合的非多孔性頂層的膜其中至 160744.doc 201237029 少一種聚合物具有遠低於該操作溫度（即，實際分離發生 之溫度）的玻璃態轉變溫度。潛在適宜之非多孔性膜之另 群組係稱為超玻璃質（superglassy)聚合物。此材料之實 例係聚（三曱基矽基丙炔）。 . 該非多孔性或奈米過濾膜典型上係承載於至少一個多孔 • 基板層上以提供必要的機械強度。適宜地，此其他多孔基 板層係由多孔材料組成，該多孔材料之孔具有大於1〇 ^ 之平均尺寸。此其他孔材料可為常用於微過濾或超過濾之 祕孔、中孔或大孔材料，諸如聚（丙烯腈"該基層之厚度 應足以提供必需的機械強度。此外，此基板可反過來承載 於另一多孔支撐物上以提供所需的機械強度。典型上，該 基層之厚度係自10至250 μιη，更適宜地自20至15〇 μιη。該 非夕孔性或奈米過濾膜與此基層結合時，該膜適宜地具有 自0.5至10 μιη ’較佳自1至5 μηΐ2厚度。 薄的頂膜層與厚的多孔支撐層之結合係通常意指複合膜 或薄膜複合物^較佳地，在本發明中，此複合膜由該膜層 及該支樓層組成’意指無其他的膜係存在於該複合膜中。 . 該膜係適當地排列使得該滲透物首先流過該膜頂層，然後 通過該基層’如此使得該膜上的壓力差推動該頂層推動至 於該基層。具有平均尺寸大於10 nm用於基層之適宜的多 孔性材料係聚（丙烯腈）、聚（醯胺醯亞胺）+ Ti〇2、聚（醚醯 亞胺）、聚二I亞乙烯及聚（四氟乙烯）。聚（丙烯腈）係尤 佳。依據本發明之一較佳組合係聚（二甲基矽氧烷）_聚（丙 稀腈）組合或聚（辛基甲基矽氧烷）-聚（丙烯腈）組合。 160744.doc 201237029 亦可使用不具有基板層之非多孔性或奈米過濾膜，但應 了解在此情況下’該膜之厚度應足以承受施加的壓力。因 此可能需要大於10 μπι之厚度。從製程經濟觀點來看此並 不佳’由於此厚膜將明顯限制該膜之通量，從而減少每單 位時間及膜面積可回收的純化產物量。 該羰基二烷酯滲透過該選擇性膜層，之後在滲透物側解 吸。用於滲透之主要驅動力係跨過該膜障壁的液體靜壓力 差（在文獻中通常稱為跨膜壓力）。 在本發明中’在該膜之滲透物側上的壓力及溫度係使得 該滲透物係低於其引起該滲透物成為液體的起泡點。亦 即，在該膜之滲透物側上的壓力應高於在給定溫度及給定 組成下之該滲透物之起泡點壓力。或者，在該膜之滲透物 側上的溫度應低於在給定壓力及給定組成下之該滲透物之 起泡點溫度。 在該分離技術中，其中「滲透蒸發」係使用膜施加，在 該膜之滲透物側上的壓力及溫度係使得該滲透物係高於其 引起s亥滲透物成為蒸汽的起泡點，其因此不同於本發明。 較佳地，在本發明中，該包含碳酸二烷酯及污染物之液 態進料之溫度（其亦可稱為本發明方法之操作溫度）係使得 在該膜之滲透物側之壓力下’無蒸汽在該膜之該側上形 成。例如，該進料溫度可為最大220t ,或最大19(rc，或 最大160°C，或最大13(rc，或最大1〇〇t>c。 相較於使用奈米多孔膜，使用非多孔性膜之優點係無堵 塞效應。意指1¾膜不η*能為在該等孔中堵塞的較大分子 160744.doc 12 201237029 所封鎖。此可發生在多孔膜中，其結果是更難以再生穩定 流量°因此，出於本發明之目的，較佳使用非多孔性或緻 密的膜。 該滞留物仍包括有價值的碳酸二烷基酯，且出於此原因 可適當地回收該滯留物至該膜分離步驟並與新鮮原料混 合。然而，當回收滯留物時，必須將部分該滯留物排出， 諸如以避免積累該或該等將藉由該膜方法自該碳酸二烷酯 分離之污染物。代替在相同方法内回收該滞留物，亦可使 其經受第二及視情況另外的分離步驟’在此情況下將第一 分離步驟之滯留物用作第二分離步驟之進料。 此外，代替回收（部分）該滯留物或在第二或視情況之另 外步驟中進一步純化，亦可將該滞留物全部排出。其中該 滯留物之組成的最似乎有益之處在於係其使得其具有作為 另一步驟中之原材料的一些價值，在此應用之前不需另外 處理該滞留物（無另外處理）。該滯留物已升級，意指其污 染物含量已降低。因此與原始產物相比，該滯留物已獲得 較高價值。與原始產物相比，該含有增加之污染物比例的 滯留物具有視該污染物濃度及感知的最終用途而定的價 值。該滯留物價值可低於或相似於該原始進料之價值。 階段削減係定義為通過該膜並作為滲透物回收的原始進 料之重量百分比。藉由調整該階段削減，可能改變滲透物 中污染物之濃度，及滯留物中該相同污染物之濃度。階段 削減越高，滯留物中污染物濃度越高。 在本發明中，該階段削減可在寬界限内變化：5至99重 160744.doc •13- 201237029 量0/。’適宜地30至95重量。/。或5〇至90重量％。 對於給疋的s亥膜之滲透率，藉由變化該跨膜壓力及/或 該進料流量可設定所期望的階段削減。第一選擇意指對於 給定的進料流量’增加跨膜壓力導致滲透物通過該膜之更 大通量或流量’並因此導致更高的階段削減。依據第二選 擇，此較高階段削減亦可藉由降低該進料流量同時保持某 種滲透物透過該膜之流量而達成。 在本發明中，通過該膜之體積流量係典型地在自5至 1000之範圍内，適宜地10至500，及更適宜地15至200 1/h/m。通過该膜之流量亦可表示為質量通量。較佳地， 通過該膜之通量係時間恆定。此外，該進口的流係以跨膜 壓力（壓力差）接觸該膜，該壓力係典型地在自1至6〇巴之範 圍内’適宜地3至35巴’且更適宜地3至25巴。該膜之滲透 率係典型地在自1至1〇〇之範圍内，適宜地2至50，及更適 宜地3至10 1/h/m2/巴。 依據本發明，含有碳酸二烷酯及污染物之液態進料可被 分離成含有碳酸二烧酯且無污染物或污染物濃度低於進料 中污染物濃度之液態滲透物，與包含碳酸二烷酯及污染物 濃度高於進料中污染物濃度的液態滯留物。 較佳地’該滲透物中污染物濃度以該滲透物之總重量計 實質上係自0至最大20, 〇〇〇 ppm w(重量百萬分率），更佳地 最大1，000 ppmw ’更佳地最大250 ppmw，更佳地最大50 ppmw ’更佳地最大1 ppmw。此滲透物可適宜地在製備聚 碳酸酯中用作原材料。 160744.doc -14- 201237029Typically, the polyoxyxene used herein contains a repeating unit, 兀-Si-0_^, which is described, for example, in U.S. Patent 5,102,551. I60744.doc 201237029 The helium atom has a hydrogen or hydrocarbyl group. Preferably, the repeating units are of the formula (I) -Si(R)(R')-〇. (1) wherein R and R' may be the same or different and represent hydrogen or are selected from alkyl or aralkyl groups. a hydrocarbyl group of a group consisting of a cycloalkyl group, an aryl group, and an alkylaryl group. Preferably, at least one of the groups R and R is an alkyl group, and the most preferred two groups are alkyl groups, more particularly methyl groups. The alkyl group may also be a 3,3,3-difluoropropyl group. Polyoxyalkylene (_OH or -NH2 terminal) polydimethyloxane and polyoctylmethyloxirane are highly suitable for the purposes of the present invention. Therefore, preferably, the polyoxyalkylene is crosslinked. This crosslinking can be affected by the reactive terminal -OH or -NH2 groups of the polyoxyalkylene. The preferred polysiloxane films are crosslinked elastomeric polyoxo films. Examples of suitable crosslinked elastomeric polyoxyalkylene membranes are broadly described in the above-referenced U.S. Patent 5,102,551. Thus, suitable membrane systems are composed, for example, of the aforementioned polyoxyalkylene polymers having a molecular weight of from 55 to 15 Å, preferably from 550 to 4,200 (before crosslinking). As a crosslinking agent, it is crosslinked with (1) polyisocyanate, or (ii) poly(carbon helium) or (iii) R4aSi(A)a, wherein 八 is ·011, _NH2, -〇R or -OOCR, a is 2, 3 or 4, and R is argon, alkyl, aryl, ring-based, aryl or aryl. Further details regarding suitable concentrating plants can be found in US 5,102,551. For the purposes of the present invention, the preferred non-porous membrane is a polydimethyl oxime or polyoctylmethyl anthrax membrane which is preferably crosslinked. Other rubber non-porous membranes can also be used. In general, a rubber film can be defined as a film having a non-porous top layer of a polymer or a combination of polymers to 160744.doc 201237029. One polymer has a temperature well below the operating temperature (ie, the temperature at which the actual separation occurs) The glass transition temperature. Another group of potentially suitable non-porous membranes is referred to as a superglassy polymer. An example of this material is poly(tridecyldecylpropyne). The non-porous or nanofiltration membrane is typically supported on at least one porous substrate layer to provide the necessary mechanical strength. Suitably, the other porous substrate layer is comprised of a porous material having pores having an average size greater than 1 〇 ^. The other pore material may be a microporous, mesoporous or macroporous material commonly used for microfiltration or ultrafiltration, such as poly(acrylonitrile). The thickness of the substrate should be sufficient to provide the necessary mechanical strength. In addition, the substrate can be reversed. It is carried on another porous support to provide the required mechanical strength. Typically, the base layer has a thickness of from 10 to 250 μηη, more suitably from 20 to 15 μηηη. The non-slip pore or nanofiltration membrane When combined with the base layer, the film suitably has a thickness of from 0.5 to 10 μm, preferably from 1 to 5 μη 2 . The combination of a thin top film layer and a thick porous support layer generally means a composite film or film composite ^ Preferably, in the present invention, the composite film consists of the film layer and the support floor 'meaning that no other film system is present in the composite film. The film system is properly arranged such that the permeate first flows through The top layer of the film is then passed through the substrate layer such that the pressure differential across the film pushes the top layer to the substrate layer. Suitable porous materials for the base layer having an average size greater than 10 nm are acrylonitrile, poly(醯) Amine Amine) + Ti〇2, poly(ether quinone imine), polydivinylidene and poly(tetrafluoroethylene). Poly(acrylonitrile) is preferred. According to one of the preferred combinations of the present invention a combination of a poly(acrylonitrile)-poly(acrylonitrile) or a poly(octylmethyloxirane)-poly(acrylonitrile). 160744.doc 201237029 Non-porous or nano-layers without a substrate layer can also be used. Filter the membrane, but it should be understood that in this case 'the thickness of the membrane should be sufficient to withstand the applied pressure. Therefore a thickness greater than 10 μπι may be required. This is not good from a process economic point of view' because this thick film will significantly limit this The flux of the membrane, thereby reducing the amount of purified product recoverable per unit time and membrane area. The carbonyl dialkyl ester permeates through the selective membrane layer and then desorbs on the permeate side. The main driving force for permeation is crossed. The hydrostatic pressure difference of the membrane barrier (commonly referred to in the literature as transmembrane pressure). In the present invention, the pressure and temperature on the permeate side of the membrane are such that the permeate is lower than it causes the permeate. Become the bubble point of the liquid. That is, in the film The pressure on the permeate side should be higher than the bubble point pressure of the permeate at a given temperature and for a given composition. Alternatively, the temperature on the permeate side of the membrane should be lower than at a given pressure and given The bubble point temperature of the permeate in the composition. In the separation technique, wherein "pervaporation" is applied using a membrane, the pressure and temperature on the permeate side of the membrane are such that the permeate system is higher than A bubble point which causes the shale to become a vapor, which is therefore different from the present invention. Preferably, in the present invention, the temperature of the liquid feed comprising dialkyl carbonate and contaminants (which may also be referred to as The operating temperature of the inventive method is such that no steam is formed on the side of the membrane under the pressure on the permeate side of the membrane. For example, the feed temperature can be a maximum of 220 t, or a maximum of 19 (rc, or a maximum of 160). °C, or a maximum of 13 (rc, or a maximum of 1〇〇t>c. The advantage of using a non-porous membrane is that there is no occlusion effect compared to the use of a nanoporous membrane. Means that the 13⁄4 film is not η* can be blocked by larger molecules that are clogged in such holes. 160744.doc 12 201237029. This can occur in the porous membrane, with the result that it is more difficult to regenerate the steady flow rate. Therefore, for the purpose of the present invention, a non-porous or dense membrane is preferably used. The retentate still includes valuable dialkyl carbonate, and for this reason the retentate can be suitably recovered to the membrane separation step and mixed with the fresh feed. However, when the retentate is recovered, a portion of the retentate must be removed, such as to avoid accumulation of the contaminants that would otherwise be separated from the dialkyl carbonate by the membrane process. Instead of recovering the retentate in the same manner, it may also be subjected to a second and optionally separate separation step' in which case the retentate of the first separation step is used as the feed for the second separation step. Alternatively, instead of recovering (partially) the retentate or further purifying it in a second or optionally additional step, the retentate may also be completely discharged. The most useful aspect of the composition of the retentate is that it has some value as a raw material in another step, which is not required to be treated separately (no additional treatment). The retentate has been upgraded to mean that its contaminant content has been reduced. Therefore, the retentate has gained a higher value than the original product. The retentate containing the increased proportion of contaminants has a value depending on the concentration of the contaminant and the perceived end use, as compared to the original product. The retentate value can be lower or similar to the value of the original feed. The stage reduction is defined as the weight percent of the original feed that is passed through the membrane and recovered as a permeate. By adjusting this stage of reduction, it is possible to change the concentration of contaminants in the permeate and the concentration of the same contaminant in the retentate. The higher the stage reduction, the higher the concentration of contaminants in the retentate. In the present invention, this stage of the cut can vary within wide limits: 5 to 99 weights 160744.doc • 13- 201237029 quantity 0/. ' Suitably 30 to 95 by weight. /. Or 5〇 to 90% by weight. The desired stage cut can be set by varying the transmembrane pressure and/or the feed flow rate for the permeability of the s 疋 membrane. The first choice means increasing the transmembrane pressure for a given feed flow rate resulting in a greater flux or flow of permeate through the membrane' and thus resulting in higher stage cuts. According to a second option, this higher stage reduction can also be achieved by reducing the feed flow while maintaining the flow of a permeate through the membrane. In the present invention, the volume flow rate through the membrane is typically in the range of from 5 to 1000, suitably from 10 to 500, and more suitably from 15 to 200 1 / h/m. The flow rate through the membrane can also be expressed as mass flux. Preferably, the flux through the membrane is constant. Furthermore, the flow of the inlet contacts the membrane at a transmembrane pressure (pressure differential), which is typically in the range of from 1 to 6 bar, suitably 3 to 35 bar and more preferably 3 to 25 bar. . The permeability of the membrane is typically in the range of from 1 to 1 Torr, suitably from 2 to 50, and more suitably from 3 to 10 1 /h/m2/bar. According to the present invention, a liquid feed containing dialkyl carbonate and contaminants can be separated into a liquid permeate containing dialkyl carbonate and having no contaminant or contaminant concentration lower than the contaminant concentration in the feed, and comprising carbonic acid A liquid retentate with an alkyl ester and a contaminant concentration higher than the contaminant concentration in the feed. Preferably, the concentration of contaminants in the permeate is substantially from 0 to a maximum of 20, 〇〇〇ppm w (parts per million by weight), and more preferably at most 1,000 ppmw of the total weight of the permeate. More preferably a maximum of 250 ppmw, more preferably a maximum of 50 ppmw 'better than a maximum of 1 ppmw. This permeate can be suitably used as a raw material in the preparation of polycarbonate. 160744.doc -14- 201237029
該膜分離將在包含一或多個膜模組的膜單元中進行。適 且模組之實例係典型地表示該膜係如何位於此模組中。此 等模組之實例係螺旋捲繞、板及框（平板）、中空纖維及管 模組。該等較佳模組組態係螺旋捲繞及板和框。最佳地， 該非多孔性或奈米過滤膜係在膜單元中應用，其包含螺旋 捲繞膜模組。此等膜模組係為技術人士所熟知，例如於 Encyclopedia of Chemical Engineering，第4版，1995, J〇hn Wiley & Sons Inc·，V〇l 16，158-164 頁中描述。螺旋捲繞模 組之實例係描述於例如US 5102551、US 5093002、US 5275726、US 5458774、US 5150118 及 WO 2006040307 中。 該碳酸一烷酯進料可溶解於溶劑中。可使用許多適宜溶 解碳酸二烷酯之溶劑，諸如乙醇、二乙醚、四氯化碳、乙 酸、丙酮及曱苯。基於碳酸二烷酯進料及溶劑之總重量的 浴劑之重量百分比可在寬界限内變化。適宜地，其係自5〇 至90重量％，更適宜地60至8〇重量0/〇。 製備待依據本發明純化之碳酸二烷酯之方法對於本發明 係無關緊要的。任何已知的製備方法可能已經應用。本發 明之方法中待處理的碳酸二烷酯可為直接自該已知製備方 法中所獲得之產物。或者，該直接獲得的碳酸二烷酯在其 依據本發明被處理之前亦可已經經歷習知的純化及回收技 術。 典型上，其中在本發明中該待純化之碳酸二烷酯係無環 碳酸二烷酯時，本發明方法中待純化的無環碳酸二烷酯 160744.doc -15- 201237029 (例如碳酸二乙酯)進料已藉由使用催化劑使烷醇(例如乙 醇）與碳酸伸㈣（例如碳酸伸乙自旨）反應職無環碳酸二烧 酯（例如，碳酸二乙酯）及單烷二醇（例如，單乙二醇）而獲 得。 此外’典型上’其中在本發明中待純化之碳酸二烧醋係 (環）碳酸伸烷酯時’本發明中待純化之碳酸伸烷酯（例如， 碳s欠伸乙s曰）進料已藉由使用催化劑使二氧化碳與環氧烧 (例如，環氧乙烷）反應形成碳酸伸烷酯（例如碳酸伸乙酯） 獲得》 在本發明方法中待純化之碳酸二烷酯進料可包括不滿足 說明書中關於雜質之最大量的碳酸二烧酯進料。 一般而言’在本發明之方法中待處理之碳酸二烷酯流包 含至少35重量％，較佳至少45重量。/。，更佳至少55重量 /〇’更佳至少6 5重量％ ’更佳至少7 5重量％，更佳至少8 5 重量°/。’及最佳至少95重量％之碳酸二烷酯。 若該待處理之碳酸二烧酯產物係相對粗製的碳酸二烧酯 流’此產物可含有基於該產物總重量計5重量％或更少之 該或該等污染物。然而，當該待處理之碳酸二烷酯產物含 有3重量％或更少，適宜地1重量％或更少，及更適宜地〇. i 重量％或更少之該或該等污染物時，本發明之方法係特別 適用的。甚至在此相對高污染物含量時，本發明之方法係 相當有效的。 若該待處理之碳酸二烷酯產物係相對純的碳酸二烷酯 流’此產物較佳含有小於500 ppmw，適宜地小於300 160744.doc 16 201237029 ppmw，更適宜地小於200 ppmw，更適宜地小於100 ppmw，更適宜地小於50 ppmw，及最適宜地小於20 PPmw 之該或該等污染物。典型上，此相對純的碳酸二烷酯進口 的流包含1至15 ppmw之該或該等污染物。 在本發明方法中待分離之碳酸二烷酯中的污染物（雜質） 可為在上述說明中提及的一或多種污染物。 本發明亦係關於製備無環碳酸二烷酯之方法，如上定義 的’包括使烷醇與碳酸伸烷酯反應得到含無環碳酸二烷酉旨 及雜質之流’並藉由膜分離自該流回收無環碳酸二烷醋， 其中使用的膜具有自〇至1〇 nm之平均孔尺寸。 此外’本發明係關於製備碳酸伸烷酯之方法，包括使二 氧化碳與環氧烷反應得到含碳酸伸烷酯及雜質之流，並藉 由膜分離自該流回收碳酸伸烷酯，其中使用的膜具有自〇 至10 nm之平均孔尺寸。 本發明藉由以下實例另外闡述。 實例1 藉由使用終端膜單元自含碳酸二烷酯之進料移除污^ 物。在此等實例中使用的實驗設置係示意性地顯示於圖1 中’其中該參考數字具有以下含義： 1 :氮氣進口 2 :進料混合物 3 :膜 4 ·渗透物出口 5 :收集容器 160744.doc • 17- 201237029 對於影響滲透物透過該膜之流量所必需的圖1之終端膜 單元之膜3上的壓力差係藉由經由氮氣進口 1進料氮氣來加 壓之方式施加《此外’該氮氣係用作蒙氣覆蓋進料混合物 2。在整個實驗期間施加的跨膜壓力係丨6巴。 該膜係支撐膜，其中具有厚度大約3 μιη之頂層係由疏水 的敏密交聯聚（二甲基矽氧烷）(PDMS)構成。該總的膜表面 積係17 cm2。 在已施加該跨膜壓力後，圖1中顯示的容器被進料填 充。隨後’在氮氣之蒙氣下開始攪拌該進料。確保該膜上 方的進料混合物2之（半）擾流《在整個實驗期間溫度係室 溫。 在實驗結束時，傾析殘留在該容器内且不作為滲透物通 過該膜的進料混合物部分並作為滯留物回收。 在表1中述及了另外的處理參數。 進料、滲透物及滞留物中鐵（Fe)之濃度係藉由感應耦合 電漿-質譜分析測定。進料、滲透物及滯留物中氣（C1)之濃 度係藉由電量滴定法測定。此外，進料、渗透物及滯留物 中該等碳酸二烷酯（即，碳酸二曱酯（DMC)、碳酸二乙醋 (DEC)及碳酸伸乙酯（eC))之濃度係藉由氣相層析法測定。 此外’色值係藉由講自Dr. Bruno Lange GmbH之LIC0300 通用比色計針對進料、滲透物及滯留物測定。測量的色值 依據APHA加德納色標（Gardner color scales)表示》該等濃 度’排斥因子及該等色值係在表1中述及。 自表1中可見實例1中Fe及C1排斥因子係有利地高（幾乎 160744.doc • 18 · 201237029 為1)。此意指僅藉由單一膜操作即可移除幾乎所有的污染 物。此外，似乎DMC及DEC係實質上並不排斥（排斥因子 分別僅0.07及0.02)。針對eC之排斥因子係0.33，其仍係有 利地小，尤其是由於在污染物之排斥因子（幾乎為1)及 eC(0.03)之排斥因子之間的不同係足夠的大以亦使得eC純 化。 表1 進料之總量：222 g 進料中DMC:DEC:eC重量比：2:1:0.4(1) 持續時間：6小時 階段削減：31重量％ 污染物：FeCl3 濃度(mg/kg) Fe Cl ...進料中 120 266 ...滲透物中 0.4 <10 ...滯留物中 220 397 排斥因子 1.0 >0.96 濃度(重量％) DMC DEC eC ...進料中 58.9 29.6 10.4 ...渗透物中 54.5 29.1 7.0 ...滯留物中 54.6 27.3 11.6 排斥因子 0.07 0.02 0.33 色值 APHA 加德納(Gardner) ...進料 >1000 5.3 …渗透物 39 0.2 ...滞留物 >1000 8.0 (1) DMC =碳酸二甲酯；DEC =碳酸二乙酯；eC =碳酸伸乙 酯。 實例2 160744.doc -19- 201237029 實例2之實驗係依據上述針對實例1的程序進行，條件為 該膜係支撐膜，其中具有厚度大約3 μιη之頂層係由疏水的 緻密交聯聚（辛基曱基矽氧烷）(P〇MS)構成，在整個實驗期 間該總膜表面積係20 cm1 2且施加的跨膜壓力係4·6巴。 在表2中，述及了另外的處理參數。 自表2可見，僅藉由單一膜操作即可獲得清晰的顏色改 善。對於兩種色量級，該滲透物之測量的色值係明顯地低 於進料。此外，顯示出DEC及eC係實質上並未被排斥。對 於兩種化合物，該等排斥因子係低於0.08。 表2 進料之總量：92.8 g 進料中DEC:eC之重量比：3:1 (1) 持續時間：4.75小時 階段削減：33重量％ 污染物：FeCl3 濃度(mg/kg) Fe Cl ...進料中(2) 199 379 濃度(重量％) DEC eC ...進料中 74.0 26.0 ...滲透物中 75.8 24.2 ...滞留物中 72.8 27.2 ...排斥因子 -0.02 0.07 色值 APHA 加德納(Gardner) ...進料 925 5.0 …渗透物 6 0 ...滯留物 959 6.0 160744.doc -20- 1 DEC=碳酸二乙酯；eC=碳酸伸乙酯。 2 值係計算的而非（分析）測定的。 201237029 【主要元件符號說明】 1 氮氣進口 2 進料混合物 3 膜 4 滲透物出口 5 收集容器 •21 160744.docThis membrane separation will be carried out in a membrane unit comprising one or more membrane modules. Examples of suitable and modular systems typically indicate how the membrane system is located in the module. Examples of such modules are spiral wound, plate and frame (plate), hollow fiber and tube modules. These preferred modular configurations are spiral wound and plate and frame. Most preferably, the non-porous or nanofiltration membrane is applied in a membrane unit comprising a spiral wound membrane module. Such membrane modules are well known to those skilled in the art and are described, for example, in Encyclopedia of Chemical Engineering, 4th Ed., 1995, J〇hn Wiley & Sons Inc., V. 16, 158-164. Examples of spiral-wound molds are described in, for example, US 5,102,551, US 5,093,002, US 5,275, 726, US 5, 458, 774, US Pat. The monoalkyl carbonate feed can be dissolved in a solvent. Many solvents suitable for dissolving the dialkyl carbonate can be used, such as ethanol, diethyl ether, carbon tetrachloride, acetic acid, acetone, and toluene. The weight percentage of the bath based on the total weight of the dialkyl carbonate feed and the solvent can vary within wide limits. Suitably, it is from 5 Torr to 90% by weight, more suitably 60 to 8 Torr, and 0/Torr. The process for preparing the dialkyl carbonate to be purified in accordance with the present invention is not critical to the present invention. Any known preparation method may have been applied. The dialkyl carbonate to be treated in the process of the present invention may be a product obtained directly from the known preparation method. Alternatively, the directly obtained dialkyl carbonate may also have undergone conventional purification and recovery techniques prior to its being treated in accordance with the present invention. Typically, in the case of the dialkyl carbonate to be purified in the present invention, the acyclic adicarbonate to be purified in the method of the present invention is 160744.doc -15-201237029 (for example, diethyl carbonate). The ester) feed has been subjected to the reaction of an alkanol (e.g., ethanol) with a carbonic acid (4) (e.g., carbonic acid) using a catalyst to work on acyclic aluminocarbonate (e.g., diethyl carbonate) and monoalkylene glycol ( For example, monoethylene glycol) is obtained. Further, 'typically' in the case of the carbonic acid bicarbonate (cyclo)carbonic acid alkyl ester to be purified in the present invention, the carbonic acid alkyl ester to be purified (for example, carbon s-ethyl s-hydrazine) in the present invention has been fed. The dialkyl carbonate feed to be purified in the process of the invention may be included by reacting carbon dioxide with an epoxy burn (e.g., ethylene oxide) to form an alkylene carbonate (e.g., ethyl acetate) using a catalyst. The dialkyl carbonate feed of the maximum amount of impurities in the specification is met. In general, the dialkyl carbonate stream to be treated in the process of the invention comprises at least 35% by weight, preferably at least 45% by weight. /. More preferably, it is at least 55 wt / 〇 'more preferably at least 65 wt% ‘more preferably at least 75 wt%, more preferably at least 8 5 wt ° /. And preferably at least 95% by weight of dialkyl carbonate. If the dialkyl carbonate product to be treated is relatively crude dialkyl carbonate stream, the product may contain 5% by weight or less based on the total weight of the product. However, when the dialkyl carbonate product to be treated contains 3% by weight or less, suitably 1% by weight or less, and more suitably 〇.% by weight or less of the or the contaminants, The method of the invention is particularly suitable. Even at this relatively high level of contaminant, the process of the present invention is quite effective. If the dialkyl carbonate product to be treated is a relatively pure dialkyl carbonate stream, the product preferably contains less than 500 ppmw, suitably less than 300 160744.doc 16 201237029 ppmw, more suitably less than 200 ppmw, more suitably Less than 100 ppmw, more suitably less than 50 ppmw, and most preferably less than 20 PPmw of the contaminant or such contaminants. Typically, this relatively pure dialkyl carbonate inlet stream contains from 1 to 15 ppmw of the contaminant or such contaminants. The contaminants (impurities) in the dialkyl carbonate to be separated in the process of the invention may be one or more of the contaminants mentioned in the above description. The present invention is also directed to a process for the preparation of acycloalkylcarbonate, as defined above, which comprises reacting an alkanol with an alkylene carbonate to give a stream containing acyclic azide and an impurity and is separated from the membrane by the membrane. The loop recovered acyclic dialkyl carbonate, wherein the membrane used had an average pore size from 〇 to 1 〇 nm. Further, the present invention relates to a process for producing an alkylene carbonate, which comprises reacting carbon dioxide with an alkylene oxide to obtain a stream containing alkyl carbonate and impurities, and recovering alkyl carbonate from the stream by membrane separation, wherein The membrane has an average pore size from 〇 to 10 nm. The invention is further illustrated by the following examples. Example 1 The soil was removed from the feed containing dialkyl carbonate by using a terminal membrane unit. The experimental setups used in these examples are schematically shown in Figure 1 'where the reference number has the following meaning: 1 : nitrogen inlet 2 : feed mixture 3 : membrane 4 · permeate outlet 5 : collection vessel 160744. Doc • 17- 201237029 The pressure difference across the membrane 3 of the terminal membrane unit of Figure 1 necessary to influence the flow of permeate through the membrane is applied by means of a nitrogen feed via a nitrogen inlet 1 Nitrogen was used as the blanket covering feed mixture 2. The transmembrane pressure applied during the entire experiment was 6 bar. The film-supporting film in which the top layer having a thickness of about 3 μm is composed of hydrophobic, densely crosslinked poly(dimethyloxane) (PDMS). The total membrane surface was 17 cm2. After the transmembrane pressure has been applied, the container shown in Figure 1 is filled with feed. The feed was then started to stir under a blanket of nitrogen. Ensure (semi) spoiler of the feed mixture 2 above the membrane "temperature system temperature throughout the experiment. At the end of the experiment, the residue remained in the vessel and was not passed as a permeate through the feed mixture portion of the membrane and recovered as a retentate. Additional processing parameters are recited in Table 1. The concentration of iron (Fe) in the feed, permeate and retentate was determined by inductively coupled plasma-mass spectrometry. The concentration of the feed, permeate and retentate gas (C1) was determined by coulometric titration. In addition, the concentration of the dialkyl carbonate (ie, didecyl carbonate (DMC), diethylene carbonate (DEC), and ethyl carbonate (eC)) in the feed, permeate, and retentate is by gas. Determine by phase chromatography. In addition, the color values were determined for feed, permeate and retentate by the LIC0300 universal colorimeter from Dr. Bruno Lange GmbH. The measured color values are expressed in accordance with the APHA Gardner color scales. The concentration and rejection values are described in Table 1. It can be seen from Table 1 that the Fe and C1 rejection factors in Example 1 are advantageously high (almost 160744.doc • 18 · 201237029 is 1). This means that almost all contaminants can be removed by a single membrane operation. In addition, it seems that the DMC and DEC systems are not substantially excluded (rejection factors are only 0.07 and 0.02, respectively). The rejection factor for eC is 0.33, which is still advantageously small, especially since the difference between the rejection factor of the contaminant factor of the contaminant (almost 1) and the eC (0.03) is sufficiently large to also eC purification. . Table 1 Total amount of feed: 222 g DMC in feed: DEC: eC Weight ratio: 2:1:0.4 (1) Duration: 6 hours Stage reduction: 31% by weight Contaminant: FeCl3 concentration (mg/kg) 120 266 in the feed of Fe Cl ... ... in the permeate 0.4 < 10 ... Retentate 220 397 Rejection factor 1.0 > 0.96 Concentration (% by weight) DMC DEC eC ... 58.9 29.6 in the feed 10.4 ... Permeate 54.5 29.1 7.0 ... Retentate 54.6 27.3 11.6 Rejection factor 0.07 0.02 0.33 Color value APHA Gardner ... Feeding > 1000 5.3 ... Permeate 39 0.2 ... Retentate > 1000 8.0 (1) DMC = dimethyl carbonate; DEC = diethyl carbonate; eC = ethyl carbonate. Example 2 160744.doc -19-201237029 The experiment of Example 2 was carried out in accordance with the procedure described above for Example 1, provided that the film-supporting film had a top layer having a thickness of about 3 μm, which was hydrophobically densely crosslinked (octyl) The composition of the total membrane surface was 20 cm 12 and the transmembrane pressure applied was 4·6 bar throughout the experiment. In Table 2, additional processing parameters are described. As can be seen from Table 2, clear color improvements can be obtained by a single membrane operation. For both color levels, the measured color value of the permeate is significantly lower than the feed. Furthermore, it is shown that the DEC and eC systems are not substantially excluded. For both compounds, the rejection factor is less than 0.08. Table 2 Total amount of feed: 92.8 g Weight ratio of DEC:eC in feed: 3:1 (1) Duration: 4.75 hours Stage reduction: 33% by weight Contaminant: FeCl3 concentration (mg/kg) Fe Cl . .. In the feed (2) 199 379 Concentration (% by weight) DEC eC ... 74.0 26.0 in the feed ... 75.8 in the permeate 24.2 ... 72.8 27.2 in the retentate ... Rejection factor -0.02 0.07 color Value APHA Gardner ... Feed 925 5.0 ... Permeate 6 0 ... Retentate 959 6.0 160744.doc -20- 1 DEC = diethyl carbonate; eC = ethyl carbonate. 2 Values are calculated rather than (analyzed). 201237029 [Explanation of main component symbols] 1 Nitrogen inlet 2 Feed mixture 3 Membrane 4 Permeate outlet 5 Collection container • 21 160744.doc