Study On Abstracting Process Of Oxytetracycline By The Group Technology Of Ultrafiltration-nanofiltration

This paper applied membrane technology to producing process of oxytetracycline, respectively studied ultrafiltration,nanofiltration and the group technology of ultrafiltration- nanofiltration, and researched and developed a new technology of cleanly production of oxytetracycline. By screening test of ultrafiltration membranes and nanofiltration membranes, this paper elected better membrane of separation performance than the others, and defineted technology parameter. As a result, membrane separation technology could reduce loss of oxytetracycline in abstracting technology, raise crystal recovery ratio, decrease absorbency of impurity, increase purity of products, and improve biochemical activity of waste water. The object matter of this paper was given below.During ultrafiltration experiment, PES-20 was selected by comparing nine membrane separation performance. Operation pressure is 0.2Mpa. Under this press, potency permeated ratio by PES-20 is 95%, ctystal recovery ratio is 94.5%, purity of product is about 97.4%. Each index is better than that of original technology.The experimental results show NF-270 was the best separation performance among three nanofiltration membrane. Operation press of nanofiltration was 1.2Mpa. Under this press, oxytetracycline rejected ratio by NF-270 was 98.2%, and this nanofiltration could wipe off part of little molecule protein and pigment. During concentration process for oxytetracycline, the result of two and half times concentrated was better. After oxytetracycline solution concentrated, crystal recovery ratio and purity of products were all raised.During experimental process of ultrafiltration-nanofiltration, membrane technology was tested better than original technology in separation and abstraction of oxytetracycline further. Average recovery ratio of PES-20 was 95%, crystal recovery was about 94.5%, purity of product was 96%, COD_cr of waste water reduced 37%. After concentrating two and half times, average crystal recovery ratio of concentrated solution of NF-270 was 96%, purity of product was 98.4%, COD_cr of waste water reduced about two and half times. So this factory could retrieve about a loss of twenty million yuan every year.