Quantitative analysis of solid and liquid contents in reactive crystallization by in-situ Raman with support vector regression

• Published in: Journal of crystal growth 2022-06, Vol.587, p.126641, Article 126641
• Main Authors: XuanYuan, ShuTian, Hao, Hongxun, Hu, Cuihong, Lan, Jinqi, Song, Tong, Xie, Chuang
• Format: Article
• Language: English
• Subjects: A1 Raman spectroscopy; A1 Reactive crystallization; A1 Supersaturated solutions; A1 Support vector regression; A2 Growth from solutions; B1 Inorganic compounds; Crystallization; Density; Quantitative analysis; Raman spectra; Raman spectroscopy; Sodium bicarbonate; Sodium carbonate; Solid suspensions; Spectrum analysis; Support vector machines; Suspension systems
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2022.126641

•The attenuation of spectrum caused by the scattering of particle has been discussed.•SVR model was developed to quantitatively analyze the composition of slurries.•Reaction crystallization process of the salt/water system was chosen.•Solution composition and crystal suspension density were accurately predicted. Quantitative analysis of crystallization processes remains challenging due to the complicated relationships among the multiple phases and their spectra. In this work, in situ Raman spectroscopy was chosen to quantitatively analyze the solution concentration and suspension density simultaneously in a crystallization process. A model based on support vector regression (SVR) was developed to separate the information of solution and solid from the Raman spectra. The simultaneous correlations of the spectra with solution concentration and suspension density were achieved and the results were evaluated. It demonstrated that the SVR-based method proposed in this work gave satisfactory fitting and prediction performance. Furthermore, the model was validated in the reactive crystallization of the ternary NaHCO3-Na2CO3-H2O system. It suggested that baseline removal is not necessary when using this model. The effect of bubbles should be included for the clear solution but could be neglected in solid suspensions. The results of this work provide a simple and rapid option for the quantitative analysis of crystallization processes and similar suspension systems.