| Lincomycin is an important lincosamide antibiotics, which is widely used and hasa broad market. There are many ways to extract lincomycin. However, these processeshave obvious drawbacks. In this paper, the extraction process of packing column wasinvestigated, followed pilot experiment. What’s more, extraction and stripping oflincomyin through hollow fiber supported liquid membrane with stripping dispersionwas researched. The mathematical mass transfer model of lincomycin was establishedto analyze mass transfer resistance and optimize the operation. The aim of theresearch is to extract lincomycin in an efficient and energy saving way.According to the principle of complex extraction, complex extraction system wasascertained with n-octanol as complexing agent and kerosene as diluent. Factorsaffecting extraction and stripping, such as n-octanol concentration, pH andconcentration of the feed solution, the ratio of phase ratio and pH of stripping solution,extraction capacity were separately studied. Besides, the composition of complex wasalso investigated. The results showed that the optimum concentration of n-octanol inthe extractant was80%(volume fraction), which could achieve the maximumextraction capacity, the suitable PH of feed solution was from10to11, thedistribution coefficient could be essentially the same when the concentration oflincomycin was greater than5g/L, the best phase ratio was3, the optimum PH ofstripping phase was1.5~2.5and the extraction and stripping efficiency were bothlarger than90%after the regeneration of mixed extraction agent to be recycled seventimes. In addition, the study also showed that one molecule of lincomycin and twomolecules of n-octanol formed hydrogen bonds under the basic conditions.The extraction process of packing column was investigated based on the optimummixed extraction agent and the paper also compared the effects on mass transfer ofdifferent kinds of packing, redistribution dishes of liquid and operation conditions.The results showed that structured packing was better than bulk packing, the best feedrates of feed phase and stripping phase were separately4m3/h and1.5m3/h and theeffect of redistribution dishes to enhance mass transfer was obvious. The capacity perunit volume of packing extraction column was12.8times to mixer settler’s, but it’scirculating volume of extraction agent was just1/12to the process of mixer settler. Then the extraction and stripping of lincomycin through hollow fiber supportedliquid membrane with stripping dispersion was researched. The paper studied theeffects of tube and shell side flow rate of membrane module on overall mass transfercoefficient and established mass transfer model. The results showed that the optimumoperation conditions were as follows: shell side flow rate500ml/min and tube sideflow rate500ml/min. The mass transfer resistances of tube side, membrane and shellside were separately509579.89s/m,1799889s/m and139056.35s/m, whichaccounted21%,74%and6%in overall mass transfer coefficient. The mass transferresistance of diffusion the membrane was the main mass transfer resistance.The above-mentioned research showed that the packing column was useful toextract lincomycin, which reduced operating costs and the amount of extraction agentand the extraction and stripping of lincomycin through hollow fiber supported liquidmembrane with stripping dispersion was effective, which could afford basic dates andresearch directions for further improvement of mass transfer. |
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