Simulation And Experiment For Recovery Technology Of Ceftriaxone Mother Liquor

A large amount of mother liquor was generated in the cephalosporin antibiotic manufacture process. A lot of good organic solvents such as dichloromethane, acetone and ethanol were included in the mother liquor. There was also some by-products which primarily is 2-Mercaptobenzothiazole (M) dissolved in the mother liquor. Distillation process was effected because the existence of 2-Mercaptobenzothiazole. And M could turn into waste residue easily. It leads to environment polluted and great waste if the waste residue is discharged without recycled. This subject mainly researched the separation and recovery process of ceftriaxone mother liquor.The solubility of M in different solvents was determined with the method of weight loss. The experiments on evaporation and concentration were carried out and the state of M in different degrees of evaporation was researched. Concentration level 15% was the optimized operation parameter for separation M from mother liquor.The azeotropic distillation for the separation of the multicomponent mixture were simulated with chemical process simulation software Aspen Plus .Water was selected as the entrainer, UNIFAC model was used to calculate the activity coefficients of the liquid phase, ideal gas equation of state was used to predict the fugacity coefficients of the gas phase, the operation parameters were optimized, and the concentration of dichloromethane in the product approaches 99.7%, the concentration of acetone approaches 99%, the concentration of ethanol(containing water) approaches 94.4%.Furthermore, the experiments on separation of the multicomponent mixture by batch distillation were carried out to confirm the simulation results. The temperature of condenser and reboiler was researched under the simulated condition. The experimental and simulation results agreed well with and that no major discrepancy was noticed. The concentration of dichloromethane was 98.1wt%, the concentration of acetone was 96.4%, and the concentration of ethanol (containing water) was 93.6%, which demonstrated that water was excellent entrainer for this system respectively.The method of evaporation and concentration pre-treatment was proposed for separation and recovery of ceftriaxone mother liquor. Compared with other methods, our method has the advantage of high yield, low energy consumption, little waste residue and small operational capacity.