摘要
谷氨酸工业结晶过程中会产生大量难以分离回收的细晶,影响收率和产品质量。文中提出了结晶-粒径切割沉降-细晶回用的工艺设想,将不同粒径的晶体分步分离,细晶浓缩后作为晶种回用至结晶过程。使用扫描电镜和粉末X-衍射(PXRD)研究细晶的晶习及其作为晶种回用的可行性,进行不同条件下的分批等电结晶,参考结晶速率、聚结度、CSD等参数确定细晶回用量、适用过饱和度范围等回用条件。结果表明:液体细晶表观为非典型四方六面体,但在谷氨酸结晶中晶面具有自我修复能力;过饱和度和细晶回用量均影响结晶过程,液体细晶的最适过饱和度范围为1-3;在过饱和度S=2时液体细晶的最适回用量(质量分数)为1%,在S=3时最适回用量为3%。最终证明通过控制合适的晶体生长环境,细晶回用的谷氨酸结晶工艺是可行的。
As a large number of fine crystals are produced in the industrial crystallization of glutamic acid,which are difficult to be reused and even reduce the yield and quality of products, a crystallization-classification settlement-fine crystal reuse craft to separate crystals was proposed according to different sizes and concentrate fine crystals which can be added to crystallization process as seed.The morphological characteristics of liquid fine crystal seed were studied by electron micrograph and powder X-ray diffraction （PXRD）,and the reuse strategy of fine crystal such as back dosage and optimal super-saturation range was determined by a series of batch crystallizations.The results show that liquid fine crystal seed has self-healing ability during the process of glutamic crystallization.The optimal super-saturation range is 1-3.The optimal back dosage is 1%when super-saturation is 2,and the optimal back dosage is 3% when super-saturation is 3.It proves that fine crystal seed can be reused effectively in a suitable condition.
出处
《化学工程》
CAS
CSCD
北大核心
2014年第6期38-42,共5页
Chemical Engineering(China)
基金
国家863高技术研究与发展计划项目(2006AA020303-02)
关键词
谷氨酸结晶
液体细晶
分布分离
晶种回用
过饱和度
glutamic acid crystallization
liquid fine seed
distributed separation
seed reuse
super-saturation
