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Crystallization of s-carboxymethyl-cysteine for its optical resolutic

s-羧甲基半胱氨酸的结晶及其光学分辨率

基本信息

批准号：
02453114
负责人：
TOYOKURA Ken
金额：
$ 3.71万
依托单位：
School of Sci. & Eng., Waseda Univ.
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02453114/
关键词：
optical resolution crystal growth rate nucleation rate purity of crystal s-carboxymethyl-cysteine

项目摘要

Crystallization phenomena of l-SCMC(s-carboxymethyl-cysteine)in supersaturated solution of dl-SCMC in the presence of sodium chloride was studied from the point of view of industrial purpose. Especially, sticking phonomena of fines on l-SCMC seed crystal and secondary nucleation by it were focused and discussed by suspended seed crystal in a batch crystallizer. In these tests, the marked seed crystal was also suspended and populations of fines found on a crystal surface were also observed, following results were obtained.1)Population of fines suspended in supersaturated solution were almost constant for initial period of batch operation. On a surface of seed crystal, fines were hardly found, but population of fines stuck on seed increased with increase of growth period of seed crystal. On these conditions, population were different by degree of supersaturation and fines were of l-SCMC. From the observation of seed surface rharked, behavior of stuck fines were modeled, and linear correlation between population rate of suspended fines and sticking rate of fines, observed were explained theoretically. When surface area of seed crystal covered by fines became about fifty percents, plots between amount of stuck fines and growing period, became deviated from theoretical line.2)Amount of d-SCMC stuck on crystal surface were observed. For initial period that fines of d-SCMC appeared on l-SCMC seed, amount of stuck d-SCMC fines increased with fourth power of operating period. After 1.5 h after d-SCMC was observed on seed surface, d-SCMC was observed in the suspended fines. From this results, heterogeneous nucleation model of d-SCMC was proposed.Fines are generally considered to be suspended in a supersaturated solution in an industrial crystallizer and affect on growth rate and quality of product crystal. When optimum design for produce of desired crystal in a crystallizer is studied, sticking phenomena of fines on growing crystal is considered important.

从工业用途的角度研究了氯化钠存在下l-SCMC（s-羧甲基半胱氨酸）在l-SCMC过饱和溶液中的结晶现象。重点讨论了悬浮种子晶体在间歇结晶器中对l-SCMC种子晶体的黏附现象及其二次成核现象。在这些测试中，标记的种子晶体也被悬浮，在晶体表面也观察到细小的种群，得到以下结果。1)过饱和溶液中悬浮微粒的数量在批量操作初期几乎是恒定的。在种晶表面几乎看不到细小颗粒，但随着种晶生长周期的延长，粘在种子上的细小颗粒数量增加。在这些条件下，l-SCMC的过饱和程度不同，种群数量也不同。通过对种子表面粘粒现象的观察，建立了粘粒行为模型，并从理论上解释了悬浮粘粒种群率与粘粒率之间的线性关系。当细粒覆盖的种晶表面积达到50%左右时，细粒附着量与生长期之间的曲线偏离了理论曲线。2)观察d-SCMC在晶体表面的粘附量。在l-SCMC种子上出现d-SCMC细粒的初始阶段，d-SCMC细粒的黏附量随着操作周期的四次幂而增加。在种子表面观察到d-SCMC后1.5 h，在悬浮细粒中观察到d-SCMC。在此基础上，提出了d-SCMC的非均相成核模型。细粒通常被认为悬浮在工业结晶器的过饱和溶液中，影响产品晶体的生长速度和质量。在研究结晶器生产所需晶体的优化设计时，细粒对生长晶体的粘附现象是一个重要的问题。