Enhanced Product Quality Control through Separation of Crystallization Phenomena in a Four-Stage MSMPR Cascade
Enhanced Product Quality Control through Separation of Crystallization Phenomena in a Four-Stage MSMPR Cascade
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DOI：
10.1021/acs.cgd.8b00941
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发表时间：
2018-12-01
影响因子：
3.8
通讯作者：
Wohlgemuth, Kerstin
中科院分区：
文献类型：
--
作者：
Luehrmann, Marie-Christine;Timmermann, Jan;Wohlgemuth, Kerstin
设计并建立了一个四级串联的MSMPR结晶器，用于生产L-丙氨酸晶体，以实现在晶体尺寸和尺寸分布方面对产品质量的增强控制。该级联的特征在于结晶现象成核和晶体生长的局部分离以及不使用泵将悬浮液从一个容器转移到下一个容器的事实。相反，选择了一种独特的容器设计，其中安装了横向和垂直溢流管，这使得通过重力进行温和的悬浮液转移成为可能。通过用合成空气充气来实现成核的受控诱导，从而得到中值直径为35 μ m的晶体。这些晶体在整个级联上生长约85 μ m，从而基本上避免了结块和破碎。为了在前三个阶段内达到稳态操作，需要约6.5 h的启动阶段。整个MSMPR级联的连续操作只能维持超过1小时，这突出了结晶过程中涉及的复杂性和不确定性。
A four-stage cascade of MSMPR crystallizers has been designed and set up for the production of L-alanine crystals to achieve an enhanced control of product quality in terms of crystal size and size distribution. The cascade is characterized by a local separation of the crystallization phenomena nucleation and crystal growth as well as by the fact that no pumps were used to transfer the suspension from one vessel to the next. Instead, a unique vessel design was chosen in which lateral and vertical overflow tubes were installed, which enabled a gentle suspension transfer by gravity. Controlled induction of nucleation was achieved by gassing with synthetic air, leading to crystals with a median diameter of 35 mu m. These crystals grew about 85 mu m over the entire cascade, whereby agglomeration and breakage were mostly avoided. To reach a steady-state operation within the first three stages, a startup phase of approximately 6.5 h was necessary. The continuous operation of the entire MSMPR cascade could only be maintained for over 1 h, underlining the complexity and uncertainty involved in the crystallization process.