| 摘要 |
<p>#CMT# #/CMT# Cleaning device (1) for the separation of a biodegradable, intermolecular cyclic diester of an alpha -hydroxycarboxylic acid (I) from material mixtures containing (I) and corresponding alpha -hydroxycarboxylic acid (II), comprises head side having at least one dephlegmator (2) and at least one outlet (3); at least one material exchange packet (4); a partition wall column (5), which is divided into two zones by a vertical partition wall (6); sump side having at least one evaporator and at least one outlet. #CMT# : #/CMT# Cleaning device (1) for the separation of a biodegradable, intermolecular cyclic diester of an alpha -hydroxycarboxylic acid compound of formula (I) from material mixtures containing (I) and corresponding alpha -hydroxycarboxylic acid compound of formula (II), comprises head side having at least one dephlegmator (2) and at least one outlet (3); at least one material exchange packet (4), which at least partially fills the diameter of the device; a partition wall column (5), which is divided into two zones by a vertical partition wall (6), where: each zone (7, 8) has at least two material exchange packets (9), which are separated from each other by a space (10), the first zone (7) (prefractioning zone) has at least an inlet (11) for feeding the material mixture and the second zone (8) (main fractioning zone) has at least one side outlet (12) for taking out the cleaned product, and to which the inlet and outlet each in the area of at least one space are arranged, at least a further material packet (13), which at least partially fills the diameter of the device; and sump side having at least one evaporator and at least one outlet, where the length ratio of the partition wall column to the total length of the cleaning device is 0.5-0.9. R : H or 1-6C-aliphatic residue. Independent claims are included for: (1) a polymerization device for the polymerization of (I) comprising the cleaning device; and (2) the separation of (I) from the material mixture containing (II) comprising feeding of the material mixture into the partition wall column containing cleaning device, where the cleaning device has at least one side outlet, separating the material mixture, where the acid of (II) gets accumulated in gas form aggregate condition, and extracting the cleaned (I) through at least one side outlet. #CMT#[Image]#/CMT# #CMT#USE : #/CMT# The cleaning device is useful: for separating and cleaning the dilactide for the preparation of essentially pure enantiomer of L-dilactide; and/or during the manufacture of polylactide. The polymerization device is useful for the preparation of polylactide (all claimed). #CMT#ADVANTAGE : #/CMT# The cleaning device provides (I) with high optical purity. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure shows the schematic representation of the cleaning device. 1 : Cleaning device 2 : Dephlegmator 3 : Outlet 4 : Material exchange packet 5 : Partition wall column 6 : Vertical partition wall 7 : First zone 8 : Second zone 9 : Two material exchange packets 10 : Space 10' : Partition wall column arranged space 11 : Inlet 12 : Outlet 13 : Further material packet. #CMT#INSTRUMENTATION AND TESTING : #/CMT# Preferred Process: The cleaning device is operated at a pressure of less than 120 mbar, preferably 100 mbar. The material mixture is originated from an upstream condensation device. The process takes place using the cleaning device and/or the polymerization device. Preferred Components: The space is arranged: between the dephlegmator and the material exchange packet and/or between the material exchange packet and the vaporizer; or between the material exchange packet and the partition wall column and/or between the partition wall column and the material exchange packet. The side outlet is present in the space arranged between the dephlegmator and the material exchange packet and/or the space arranged between the material exchange packet and the partition wall column. The vaporizer is a falling film vaporizer. The main fractioning zone of the partition wall column has three material exchange packets, where the material exchange packets each are separated by the space. The spaces at least have one side outlet, where only one of the two spaces has a side outlet. To at least on one of the side outlet, at least one further cleaning device comprising rectification- and/or crystallization- device, is attached. To at least on one of the side outlet, at least one further cleaning device comprising rectification- and/or crystallization device, is attached. To at least on one of the side outlet of the partition wall column, comprising rectification- and/or crystallization device, is attached. The further cleaning device is connected with the inlet of the partition wall column through a reefed. On one side outlet between the material exchange packet and the partition wall column arranged space (10'), at least one rectification column is attached. The rectification column has at least a material exchange packet. The sump side arranged part of the rectification column is connected with the inlet of the partition wall column through a recirculation. To, at least one of the side outlets of the partition wall column, at least one crystallization device is attached, which is preferably connected with the inlet of the partition wall column through a recirculation. The cleaning device has at least one polymerization reactor in its downstream. The polymerization reactor has at least one agitating tub downstream and comprises at least one flow reactor. The cleaning device has at least one condensation device downstream. #CMT#[Image]#/CMT# #CMT#ORGANIC CHEMISTRY : #/CMT# Preferred Process: The material mixture of the partition wall column is fed in gas form, liquid and/or as two phase mixture. The material mixture, which is to be separated is supplied into the separation column of the cleaning device at 90-210[deg] C, preferably 110-140[deg] C. The process further comprises separating L- and meso-dilactide, after the successful removing the separated separation of dilactide; simultaneously separating the dilactide in meso-dilactide rich fraction and L-dilactide-rich fraction, where the meso-dilactide-rich fraction is extracted from at least one first side outlet and the L-dilactide-rich fraction is extracted from a second side outlet with the condition that the first side outlet in relation to the second side outlet is arranged on the cleaning device further towards the head side. The further separation step is a rectification or crystallization step. The content of L-dilactide in the meso-dilactide-rich fraction is maximum 60 wt.%, preferably 40 wt.%. The content of the meso-dilactide in the L-dilactide-rich fraction is further limited by the subsequent crystallization. The mesodilactide-rich fraction of the material mixture separated by crystallization, which gets supplied to the separation wall column, is loaded again. The content of the L-dilactide in the meso-dilactide-rich fraction is decreased by the subsequent rectification. The L-dilactide-fraction of the material mixture separated by means of rectification, which supplied to the separation wall column is loaded again. Preferred Components: (I) is extracted in liquid aggregate condition. (I) is obtained with such a purity, that the concentration of free carboxylic acids group is maximum 50, preferably 20 mmol/kg. (II) is extracted as the main product. The material mixture further contains at least one further material comprising of water and/or corresponding oligomers of alpha -hydroxycarboxylic acid compound of formula (III), where water is extracted as main product and/or the oligomers of alpha -hydroxycarboxylic acid is extracted as sump product. The weight part of (I) fed into the cleaning device is at least 50 wt %, preferably greater than 80 wt.%. (I) is dilactide, and (II) is lactic acid. The content of the meso-dilactide in the L-dilactide-rich fraction is maximum 10 wt.%, preferably 4 wt.%. n : 1-10.</p> |
