Method for separating trioxane from a mixture containing trioxane, formaldehyde and water
    1.
    发明申请
    Method for separating trioxane from a mixture containing trioxane, formaldehyde and water 审中-公开
    从含有三恶烷,甲醛和水的混合物中分离三恶烷的方法

    公开(公告)号:US20070155972A1

    公开(公告)日:2007-07-05

    申请号:US10583696

    申请日:2004-12-21

    IPC分类号: C07D305/12 C07C41/03

    摘要: A process for removing trioxane from a mixture I of formaldehyde, trioxane and water, by a) distilling the mixture I in a first distillation stage at a pressure of from 0.1 to 2 bar to obtain a stream II which comprises formaldehyde and a stream III which comprises predominantly trioxane and additionally water and formaldehyde, b) mixing the stream III with a recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde to obtain a stream IIIa which comprises predominantly trioxane and additionally water and formaldehyde, c) distilling the stream IIIa, if appropriate after removing low boilers from the stream III or IIIa in a further distillation stage, in a second distillation stage at a pressure of from 0.2 to 10 bar, the pressure in the second distillation stage being at least 0.1 bar higher than the pressure in the first distillation stage, to obtain a stream IV of trioxane and a stream V which comprises predominantly trioxane and additionally water and formaldehyde, d) distilling the stream V in a third distillation stage at a pressure of from 0.1 to 4 bar to obtain a stream VI which comprises predominantly water and additionally formaldehyde, and the recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde, e) if appropriate, distilling the stream VI in a fourth distillation stage to obtain a stream VIII which comprises predominantly water, and a stream IX which comprises predominantly formaldehyde.

    摘要翻译: 一种从甲醛,三恶烷和水的混合物I中除去三恶烷的方法,通过以下步骤a)在0.1至2巴的压力下在第一蒸馏阶段中蒸馏混合物I以获得包含甲醛和流III的流II 主要包含三恶烷,另外还含有水和甲醛,b)将流III与主要包含三恶烷,另外含有水和甲醛的再循环流VII混合,得到主要含有三恶烷,另外含有水和甲醛的流IIIa,c)蒸馏流IIIa 如果适当,则在进一步蒸馏阶段从流III或IIIa除去低锅炉后,在0.2至10巴的压力的第二蒸馏阶段中,第二蒸馏阶段中的压力比压力高至少0.1巴 在第一蒸馏阶段,获得三恶烷的流IV和主要包含三恶烷并另外包含的流V 和d)在0.1至4巴的压力下在第三蒸馏阶段中蒸馏物流V以获得主要包含水和另外甲醛的物流VI,以及主要包含三恶烷和另外的水的再循环流VII,以及 甲醛,e)如果合适,在第四蒸馏阶段中蒸馏物流VI以获得主要包含水的物流VIII和主要包含甲醛的物流IX。

    Integrated Process For Preparing Trioxane From Formaldehyde
    2.
    发明申请
    Integrated Process For Preparing Trioxane From Formaldehyde 审中-公开
    甲醛制备三恶烷的综合工艺

    公开(公告)号:US20080194845A1

    公开(公告)日:2008-08-14

    申请号:US11997619

    申请日:2006-07-19

    IPC分类号: C07D323/06

    CPC分类号: C07D323/06 Y02P20/125

    摘要: The invention relates to an integrated process for preparing trioxane from formaldehyde, comprising the steps of: a) a stream A1 comprising water and formaldehyde and a recycle stream B2 consisting substantially of water and formaldehyde are fed to a trioxane synthesis reactor and allowed to react to obtain a product stream A2 comprising trioxane, water and formaldehyde; b) stream A2 is fed to a first low-pressure distillation column and distilled at a pressure of from 0.1 to 2.5 bar to obtain a stream B1 enriched in trioxane and additionally comprising water and formaldehyde, and the recycle stream B2 consisting substantially of formaldehyde and water; c) stream B1 and a recycle stream D1 comprising trioxane, water and formaldehyde are fed to a second low-pressure distillation column and distilled at a pressure of from 0.1 to 2.5 bar to obtain a stream C1 comprising predominantly trioxane and additionally formaldehyde and water, and a stream C2 consisting substantially of formaldehyde and water; d) stream C1 is fed to a high-pressure distillation column and distilled at a pressure of from 0.2 to 17.5 bar to obtain the recycle stream D1 and a product stream D2 consisting substantially of trioxane, in which a removal of the low boilers present in streams B1 or C1 may be undertaken between steps b) and c) or c) and d).

    摘要翻译: 本发明涉及从甲醛制备三恶烷的综合方法,包括以下步骤:a)将包含水和甲醛的流A 1和基本上由水和甲醛组成的循环流B 2加入到三恶烷合成反应器中, 反应以获得包含三恶烷,水和甲醛的产物流A 2; b)将料流A 2加入到第一低压蒸馏塔中并在0.1至2.5巴的压力下蒸馏以获得富含三恶烷并另外包含水和甲醛的料流B 1,并且再循环料流B 2基本上 的甲醛和水; c)料流B 1和包含三恶烷,水和甲醛的再循环料流D 1进料到第二低压蒸馏塔中,并在0.1至2.5巴的压力下蒸馏以获得主要含有三恶烷和另外的甲醛的料流C 1 和水,以及基本上由甲醛和水组成的料流C 2; d)将料流C 1加入高压蒸馏塔中,并在0.2至17.5巴的压力下进行蒸馏,以获得基本上由三恶烷组成的再循环流D 1和产物流D 2,其中将低 在流B 1或C 1中存在的锅炉可以在步骤b)和c)或c)和d)之间进行。

    Integrated Method For the Production of Trioxane From Formaldehyde
    3.
    发明申请
    Integrated Method For the Production of Trioxane From Formaldehyde 审中-公开
    甲醛生产三恶烷的综合方法

    公开(公告)号:US20080281109A1

    公开(公告)日:2008-11-13

    申请号:US12063155

    申请日:2006-08-01

    IPC分类号: C07D323/06

    CPC分类号: C07D323/06 Y02P20/125

    摘要: The invention relates to an integrated process for preparing trioxane from formaldehyde in which, in a first step, a stream A1 comprising water and formaldehyde and a recycle stream B2 consisting substantially of water and formaldehyde are fed to a trioxane synthesis reactor in which the formaldehyde is converted to trioxane to obtain a product stream A2 comprising trioxane, water and formaldehyde. Stream A2 and a recycle stream D1 comprising trioxane, water and formaldehyde are fed to a first distillation column and distilled at a pressure in the range from 0.1 to 2.5 bar to obtain a stream B1 enriched in trioxane, and the stream B2 consisting substantially of water and formaldehyde. Stream B1 is fed to a second distillation column and distilled at a pressure in the range from 0.2 to 17.5 bar to obtain a product stream C2 consisting substantially of trioxane, and a stream C1 comprising trioxane, water and formaldehyde. Stream C1 is fed to a third distillation column and distilled at a pressure in the range from 1 to 10 bar to obtain the recycle stream D1 comprising trioxane, water and formaldehyde, and a stream D2 consisting substantially of water.

    摘要翻译: 本发明涉及从甲醛制备三恶烷的综合方法,其中在第一步中,将包含水和甲醛的料流A 1和基本上由水和甲醛组成的再循环料流B 2加入到三恶烷合成反应器中,其中 将甲醛转化成三恶烷,得到包含三恶烷,水和甲醛的产物流A 2。 将流A 2和包含三恶烷,水和甲醛的再循环流D 1加入到第一蒸馏塔中,并在0.1-2.5巴的压力下蒸馏,得到富含三恶烷的料流B 1,并且料流B 2 基本上由水和甲醛组成。 将料流B 1加入到第二蒸馏塔中,在0.2至17.5巴的压力下蒸馏,得到基本上由三恶烷组成的产物流C 2和包含三恶烷,水和甲醛的料流C 1。 将料流C 1加入到第三蒸馏塔中并在1至10巴的压力下进行蒸馏以获得包含三恶烷,水和甲醛的再循环流D 1和基本上由水组成的料流D 2。

    INTEGRATED METHOD FOR PRODUCING TRIOXANE FROM FORMALDEHYDE
    4.
    发明申请
    INTEGRATED METHOD FOR PRODUCING TRIOXANE FROM FORMALDEHYDE 审中-公开
    用于从甲醛生产三氧化二铁的综合方法

    公开(公告)号:US20100152466A1

    公开(公告)日:2010-06-17

    申请号:US12063171

    申请日:2006-08-04

    IPC分类号: C07D323/06

    CPC分类号: C07D323/06 Y02P20/125

    摘要: The invention relates to an integrated process for preparing trioxane from formaldehyde in which a stream A1 comprising water and formaldehyde and a recycle stream B2 consisting substantially of water and formaldehyde are fed to a trioxane synthesis reactor in which the formaldehyde is converted to trioxane to obtain a product stream A2 comprising trioxane, water and formaldehyde; stream A2 is fed to a first distillation column and distilled at a pressure in the range from 0.1 to 2.5 bar to obtain a stream B1 enriched in trioxane, and the stream B2 consisting substantially of water and formaldehyde; stream B1 and a recycle stream D1 comprising trioxane, water and formaldehyde are fed to a second distillation column and distilled at a pressure in the range from 0.2 to 17.5 bar to obtain a product stream C2 consisting substantially of trioxane, and a stream C1 comprising trioxane, water and formaldehyde; stream C1 is fed to a third distillation column and distilled at a pressure in the range from 0.1 to 2.5 bar to obtain the recycle stream D1 comprising trioxane, water and formaldehyde, and a stream D2 consisting substantially of water and formaldehyde.

    摘要翻译: 本发明涉及从甲醛制备三恶烷的综合方法,其中将包含水和甲醛的流A1和基本上由水和甲醛组成的再循环流B2进料到三恶烷合成反应器中,其中甲醛被转化成三恶烷,以获得 产物流A2包含三恶烷,水和甲醛; 将料流A2加入到第一蒸馏塔中,并在0.1-2.5巴的压力下进行蒸馏,得到富含三恶烷的料流B1,基本上由水和甲醛组成的料流B2; 将料流B1和包含三恶烷,水和甲醛的再循环流D1进料至第二蒸馏塔,并在0.2至17.5巴的压力下蒸馏,得到基本上由三恶烷组成的产物流C2和包含三恶烷的料流C1 ,水和甲醛; 将料流C1进料至第三蒸馏塔并在0.1-2.5巴的压力下进行蒸馏以获得包含三恶烷,水和甲醛的再循环流D1和基本上由水和甲醛组成的料流D 2。

    Method for separating trioxane from a trioxane/formaldehyde/water mixture by means of pressure change rectification

    公开(公告)号:US20070272540A1

    公开(公告)日:2007-11-29

    申请号:US10583698

    申请日:2004-12-21

    IPC分类号: B01D3/00 C07D323/06

    CPC分类号: C07D323/06

    摘要: A process for removing trioxane from a use stream I of formaldehyde, trioxane and water, by a) providing a use stream I which comprises formaldehyde as the main component and trioxane and water as the secondary components, b) mixing the use stream I with a recycle stream VII which comprises trioxane as the main component and formaldehyde and water as the secondary components to obtain a feed stream Ia which comprises formaldehyde as the main component and trioxane and water as the secondary components, c) distilling the use stream Ia in a first distillation stage at a pressure of from 0.1 to 2.5 bar to obtain a stream II which comprises formaldehyde as the main component and water as the secondary component, and a stream III which comprises trioxane as the main component and water and formaldehyde as the secondary components, d) distilling the stream III, optionally after removing low boilers from the stream III in a low boiler removal stage, in a second distillation stage at a pressure of from 0.2 to 17.5 bar, the pressure in the second distillation stage being from 0.1 to 15 bar higher than the pressure in the first distillation stage, to obtain a stream IV which consists substantially of trioxane and a stream V which comprises trioxane as the main component and water and formaldehyde as the secondary components, e) optionally mixing the stream V with a stream IX which comprises water as the main component to obtain a stream Va having a higher water content than the stream V, the stream Va comprising trioxane as the main component and water and formaldehyde as the secondary components, f) distilling the stream V or Va in a third distillation stage at a pressure of from 1 to 10 bar to obtain a stream VI which consists substantially of water and the recycle stream VII which comprises trioxane as the main component and water and formaldehyde as the secondary components

    Method for separating trioxane from a trioxane/formaldehyde/water mixture by means of pressure change rectification
    6.
    发明授权
    Method for separating trioxane from a trioxane/formaldehyde/water mixture by means of pressure change rectification 有权
    通过压力变换精馏从三恶烷/甲醛/水混合物中分离三恶烷的方法

    公开(公告)号:US07713387B2

    公开(公告)日:2010-05-11

    申请号:US10583698

    申请日:2004-12-21

    IPC分类号: B01D3/00 C07D323/06 C07C45/78

    CPC分类号: C07D323/06

    摘要: A process for removing trioxane from a use stream I of formaldehyde, trioxane and water, by a) providing a use stream I of formaldehyde as the main component and trioxane and water as the secondary components, b) mixing the use stream I with a recycle stream VII to obtain a feed stream Ia, c) distilling the use stream Ia in a first distillation stage to obtain a stream II of formaldehyde as the main component and water as the secondary component, and a stream III of trioxane as the main component and water and formaldehyde as the secondary components, d) distilling the stream III in a second distillation stage having a pressure higher than in the first distillation stage, to obtain a stream IV of trioxane and a stream V of trioxane as the main component and water and formaldehyde as the secondary components, e) distilling the stream V in a third distillation stage to obtain a stream VI of water and the recycle stream VII of trioxane as the main component and water and formaldehyde as the secondary components.

    摘要翻译: 一种从甲醛,三恶烷和水的使用流I中除去三恶烷的方法,通过以下步骤:a)提供以甲醛为主要成分的使用流I和作为第二组分的三恶烷和水,b)将使用流I与再循环 流VII以获得进料流Ia,c)在第一蒸馏阶段中蒸馏出使用流Ia以获得作为主要组分的甲醛的流II和作为第二组分的水,以及作为主要组分的三恶烷的流III和 水和甲醛作为次要组分,d)在具有高于第一蒸馏阶段的压力的第二蒸馏阶段中蒸馏料流III,得到三恶烷的流IV和三恶烷的流V作为主要成分, 甲醛作为次要组分,e)在第三蒸馏阶段中蒸馏物流V以获得水的流VI和三恶烷的再循环流VII作为主要成分,水和甲醛为t 他的次要成分。

    METHOD FOR PRODUCING TRIOXANE FROM TRIOXYMETHYLENE GLYCOL DIMETHYL ETHER
    7.
    发明申请
    METHOD FOR PRODUCING TRIOXANE FROM TRIOXYMETHYLENE GLYCOL DIMETHYL ETHER 审中-公开
    从三甲基乙二醇二甲基醚生产三氧化硅的方法

    公开(公告)号:US20100130756A1

    公开(公告)日:2010-05-27

    申请号:US12593964

    申请日:2008-03-27

    IPC分类号: C07D323/06

    CPC分类号: C07D323/06

    摘要: A process for preparing trioxane from trioxymethylene glycol dimethyl ether (POMDMEn=3) by converting trioxymethylene glycol dimethyl ether in the presence of an acidic catalyst and subsequent distillative workup of the reaction mixture, comprising the steps of: a) feeding trioxymethylene glycol dimethyl ether (POMDMEn=3) or a mixture comprising trioxymethylene glycol dimethyl ether into a reactor and converting it in the presence of an acidic catalyst to a mixture a comprising trioxane, formaldehyde, water, methylene glycol (MG), polyoxymethylene glycols (MGn>1), methanol, hemiformals (HF), methylal (POMDMEn=1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>1); b) distillatively separating the reaction mixture a into a low boiler fraction b1 comprising trioxane, formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2), and a high boiler fraction b2 comprising polyoxymethylene glycols (MGn>1), hemiformals (HFn>1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>2); c) distillatively separating the low boiler fraction b1 into a low boiler fraction c1 comprising formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2), and a high boiler fraction c2 comprising trioxane.

    摘要翻译: 一种通过在酸性催化剂存在下转化三甘醇二甲醚和随后的反应混合物的蒸馏后处理由三甘醇二甲醚(POMDMEn = 3)制备三恶烷的方法,包括以下步骤:a)将三亚甲基二醇二甲醚 POMDMEn = 3)或包含三亚甲基二醇二甲醚的混合物加入到反应器中并在酸性催化剂存在下将其转化为包含三恶烷,甲醛,水,亚甲基二醇(MG),聚氧化亚甲基二醇(MGn1), 甲醇,半缩甲醛(HF),甲缩醛(POMDMEn = 1)和聚氧化亚甲基二醇二甲醚(POMDMEn> 1); b)将反应混合物a蒸馏分离成包含三恶烷,甲醛,水,亚甲基二醇,甲醇,半缩甲醛(HFn = 1),甲缩醛和二甲亚甲基二醇二甲醚(POMDMEn = 2)的低沸点馏分b1和高沸点馏分 b2包含聚甲醛二醇(MGn> 1),半缩甲醛(HFn1)和聚甲醛二醇二甲醚(POMDMEn> 2); c)将低沸点馏分b1蒸馏分离成包含甲醛,水,亚甲基二醇,甲醇,半缩甲醛(HFn = 1),甲缩醛和二羟甲基二醇二甲醚(POMDMEn = 2)的低沸点馏分c1,以及高锅炉馏分c2 包括三恶烷。

    METHOD FOR PRODUCING CYCLIC FORMALDEHYDE DERIVATIVES FROM POLYOXY DIALKYL ETHERS
    8.
    发明申请
    METHOD FOR PRODUCING CYCLIC FORMALDEHYDE DERIVATIVES FROM POLYOXY DIALKYL ETHERS 审中-公开
    从多羟基二烷基醚生产环状甲醛衍生物的方法

    公开(公告)号:US20100145079A1

    公开(公告)日:2010-06-10

    申请号:US12532430

    申请日:2008-03-27

    IPC分类号: C07D323/06

    CPC分类号: C07D323/06

    摘要: A process for preparing trioxane from trioxymethylene glycol dimethyl ether (POMDMEn=3) by converting trioxymethylene glycol dimethyl ether in the presence of an acidic catalyst and subsequent distillative workup of the reaction mixture, comprising the steps of: a) feeding trioxymethylene glycol dimethyl ether (POMDMEn=3) or a mixture comprising trioxymethylene glycol dimethyl ether into a reactor and converting it in the presence of an acidic catalyst to a mixture a comprising trioxane, formaldehyde, water, methylene glycol (MG), polyoxymethylene glycols (MGn>1), methanol, hemiformals (HF), methylal (POMDMEn=1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>1); b) distillatively separating the reaction mixture a into a low boiler fraction b1 comprising formaldehyde, water, methylene glycol, methanol, hemiformal (HFn=1), methylal and dioxymethylene glycol dimethyl ether (POMDMEn=2), and a high boiler fraction b2 comprising trioxane, polyoxymethylene glycols (MGn>1), hemiformals (HFn>1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>2); c) distillatively separating the high boiler fraction b2 into a low boiler fraction c1 comprising trioxane, and a high boiler fraction c2 comprising polyoxymethylene glycols (MGn>1), hemiformals (HFn>1) and polyoxymethylene glycol dimethyl ethers (POMDMEn>2).

    摘要翻译: 一种通过在酸性催化剂存在下转化三甘醇二甲醚和随后的反应混合物的蒸馏后处理由三甘醇二甲醚(POMDMEn = 3)制备三恶烷的方法,包括以下步骤:a)将三亚甲基二醇二甲醚 POMDMEn = 3)或包含三亚甲基二醇二甲醚的混合物加入到反应器中并在酸性催化剂存在下将其转化为包含三恶烷,甲醛,水,亚甲基二醇(MG),聚氧化亚甲基二醇(MGn1), 甲醇,半缩甲醛(HF),甲缩醛(POMDMEn = 1)和聚氧化亚甲基二醇二甲醚(POMDMEn> 1); b)将反应混合物a蒸馏分离成包含甲醛,水,亚甲基二醇,甲醇,半缩甲醛(HFn = 1),甲缩醛和二甲亚甲基二醇二甲醚(POMDMEn = 2)的低沸点馏分b1,以及高沸点馏分b2, 三氧杂环己烷,聚甲醛(MGn> 1),半缩甲醛(HFn1)和聚甲醛二醇二甲醚(POMDMEn> 2); c)将高沸点馏分b2蒸馏成包含三恶烷的低沸点馏分c1和包含聚甲醛二醇(MGn> 1),半缩甲醛(HFn1)和聚甲醛二醇二甲醚(POMDMEn2)的高沸点馏分c2。

    Method for preparing highly concentrated, gaseous formaldehydes
    9.
    发明申请
    Method for preparing highly concentrated, gaseous formaldehydes 失效
    制备高浓度气态甲醛的方法

    公开(公告)号:US20060185513A1

    公开(公告)日:2006-08-24

    申请号:US10547440

    申请日:2004-03-03

    IPC分类号: B01D19/00

    摘要: Process for preparing high-concentration gaseous formaldehyde having a molar CH2O:H2O ratio of ≧0.6 from an aqueous formaldehyde solution by evaporation of at least part of the solution, in which the aqueous formaldehyde solution is heated to a vaporization temperature T and the gas phase formed is taken off, wherein the evaporation temperature T obeys the relationship: T[° C.]≧T′min[° C.] where T′min(c)=A+B×(c/100)+C×(c/100)2+D×(c/100)3 and A=+68.759, B=+124.77, C=−12.851, D=−10.095, where c is the instantaneous CH2O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

    摘要翻译: 从甲醛水溶液中制备具有摩尔CH 2 H 2 O:H 2 O 2比值> 0.6的高浓度气态甲醛的方法,通过蒸发至少部分 溶液,其中将甲醛水溶液加热至蒸发温度T,取出形成的气相,其中蒸发温度T遵循以下关系:<?in-line-formula description =“In-line formula”end = “lead”?> T [°C]> = T'分钟<°C。<?in-line-formula description =“In-line Formulas”end =“tail”?> 其中T'分钟(c)= A + Bx(c / 100)+ Cx(c / 100)2 + Dx(c / 100) / SUP>和A = + 68.759,B = + 124.77,C = -12.851,D = -10.095,其中c是蒸发期间甲醛水溶液的瞬时CH 2 O 2含量百分比 为20〜99重量%。

    Method for producing polyoxymethylene dimethyl ethers from methanol and formaldehyde
    10.
    发明授权
    Method for producing polyoxymethylene dimethyl ethers from methanol and formaldehyde 失效
    从甲醇和甲醛生产聚甲醛二甲醚的方法

    公开(公告)号:US07671240B2

    公开(公告)日:2010-03-02

    申请号:US11917528

    申请日:2006-06-12

    IPC分类号: C07C41/56 C08G2/08

    摘要: Processes for preparing tri- and tetraoxymethylene glycol dimethyl ether (POMDMEn=3,4) include feeding a reaction mixture of an aqueous formaldehyde solution and methanol into a reactive evaporator and separating into a first low boiler fraction and a first high boiler fraction, recycling the first high boiler fraction into the reactor, feeding the first low boiler fraction into a first distillation column and separating into a second low boiler fraction and a second high boiler fraction, recycling the second high boiler fraction into the reactive evaporator, feeding the second low boiler fraction into a second distillation column and separating into a third low boiler fraction and a third high boiler fraction, feeding the third high boiler fraction into a phase separation apparatus and separating into an aqueous phase and an organic phase, and feeding the organic phase into a third distillation column and separating into a low and high boiler fractions.

    摘要翻译: 制备三 - 和四甲基二醇二甲醚(POMDMEn = 3,4)的方法包括将甲醛水溶液和甲醇的反应混合物进料到反应蒸发器中,并分离成第一低沸点馏分和第一高沸点馏分,循环利用 将第一高锅炉馏分进入反应器,将第一低沸点馏分进料到第一蒸馏塔中并分离成第二低沸点馏分和第二高沸点馏分,将第二高沸点馏分再循环到反应蒸发器中,将第二低沸点馏分 将馏分分馏成第二蒸馏塔并分离成第三低沸点馏分和第三高沸点馏分,将第三高沸点馏分进料到相分离装置中并分离成水相和有机相,并将有机相进料至 第三蒸馏塔并分离成低和高沸点馏分。