Initial Solvent Screening and Continuous Co-crystallization of Vanillin and Phenazine as a Separation Technology

• Main Authors: Hsin-Rong Chen, 陳鑫榮
• Other Authors: Tu Lee
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/01404604651660218883

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 100 === Separation and purification technologies can be seen in the pharmaceutical industry, mining industry, the food industry, petrochemical industry and other need purgative industry. We have devised a process to use a molecule (i.e. phenazine) which can form co-crystals (i.e. 1:2 co-crystals of phenazine-vanillin) with the final product (i.e. vanillin) by temperature cooling. Co-crystallization of 1:2 co-crystals of phenazine-vanillin can be use to separate vanillin from other by-products such as vanillyl alcohol in bio-based reactions. Initial solvent screening method is also used to identify synthesis solvents and decomplexation solvents of 1:2 co-crystals of phenazine-vanillin. Finally, 1:2 co-crystals of phenazine-vanillin can be prepared in toluene, then we extended it to continuous co-crystallization and adjust different volume flow rates (i.e. 50, 70, 90 ml/min ). We looked at different volume flow rates to see the corresponding change of size distribution. We observed that crystals increased in sizes with the increase in the mean residence time. We hope that through the integration of separation and continuous co-crystallization technology, new options can be provided for manufacturing purification steps. We also list out the significant contributions of this thesis. We made 1:2 co-crystals of phenazine-vanillin in toluene, We found out 1:2 co-crystals of phenazine-vanillin have two different forms with m.p. = 90oC and m.p. = 97 oC, We used solvent screening method to find out that MTBE, acetone, DMSO and methanol can decomplex separate 1:2 co-crystals of phenazine-vanillin, (4) We successfully made 1:2 co-crystals of phenazine-vanillin by continuous co-crystallization by temperature cooling, (5) We compared the mass balance of continuous co-crystallization and batch co-crystallization individually, and continuous co-crystallization has a better yield (51.2%), and the one for batch co-crystallization (34.9%). (6) We calculated crystal growth rates and nucleation rates for continuous co-crystallization with the one of batch co-crystallization. By mixed suspension, mixed product removal (MSMPR) model Growth rate: Batch co-crystallization (4.1×10-4 mm/s) > continuous co-crystallization (2.6×10-4 mm/s). Nucleation rate: Continuous co-crystallization (2.8×104 no./l∙s)> batch co-crystallization (3.4×103 no./l∙s).