| 6-APA for preparation of semi-synthetic penicillin was made by cleavage of penicillin using an immobilized acylase. Penicillin G or Penicillin V is converted into 6-APA by the reaction of removing the side chain linked to the amino group in position 6. Penicillins consist of the heterocyclic group consisting of a thiazolidine ring fused with a beta-lactam ring, which are distinguished from each other by the nature of the side chain attached to the amine group in position 6 through a peptide link. How to isolate and purify 6-APA from the direct Pen G cleavage broth is very important in the whole process of the 6-APA production. The most widely-used process comprises performing a liquid-liquid extraction at acid pH using appropriate equipment capable of dealing the emulsions which form between the organic and the organic solvent. But the efficiency of liquid extraction is affected by temperature control, loss of activity in the broth, which is exhausted broth through deactivation at acid pH and the physical loss connected with inadequate separation of the organic phase, which may remain included, and which in any case requires costly equipment, the use of surfactants, which consequence on costs and environmental problems, and the use of solvents. In order to overcome some of the problems which now exist in the production of 6-APA, we propose a new method which is using exchange resins. The purification using resins achieves not only isolation of the 6-APA and PAA, but also their simultaneous separation in one operation, even though sequential, through control elution.This paper consists of six parts which are screening out the appropriate resins and the suitable eluents, study of the adsorption performance ;ind the desorption performance, research in the separation of 6-APA and PAA as well as establishing the mathematical model for our study system.Firstly, three weak-base resins are selected for their adsorption proportion higher than 95%. They are IRA67, D301 and 330 resins. From the ion-exchange resin isotherm and their linearity-regression, we prove that the adsorption of the three resins accord witkthe Langmuir model. Their equilibrium relations are Q=C/(0.3221+0.0136C), Q=C/(0.025+0.0085C), Q=C/(0.0034+0.005C)respectively. Secondly, 20% ehanol, 20% isopropanol are selected as good eluents to elute 6-APA from resins. The dynamic experiments further show that 20% ethanol and 20% isopropanol are good for their high elution speed and large distribution ratio of 6-APA in the liquid phase etc.. Choose D301 resin as sorbent and 20% isopropanol as eluent, the recovery of 6-APA is 86.8%, which is 6.8 percent more than the recovery of 6-APA through liquid-liquid extraction process. The concentration of 6-APA in the eluate is 5.1 mg/ml (equal to 1,3515 u/ml), which can simplify the concentrated stage before crystallization. Choose IRA67 resin as sorbent and 20% ethanol as eluent, 6-APA and PAA can be separated effectively. Finally, combining the interior diffusion, surface adsorption with outer diffusion, we establish the mathematical model which is suitable for our study system. The equilibrium model of stirring state is:The equilibrium model of immobilized bed is:...
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