A Study On Recovery Of Butyl Acetate From Wastewater From Penicillin Producing Process By Foam Separation

Butyl acetate in the wastewater of penicillin plant should be recovered to decrease the production cost and to improve the environmental protection. Some traditional methods such as azeotropic distillation and stripping are used to recover such organic materials, with some undesired problems, such as clogging and erosion of equipment, rather high energy consumption and hydrolysis of organic materials under heating condition. So it is necessary to develop a new and better separation technology to recover organics in the wastewater from the penicillin plant.Foam separation is a kind of novel technology based on the air-water interfacial phenomena and has been used to separate trace organics in wastewater. Thereinto, solvent sublation has a number of advantages that make it an attractive method to concentrate the organics in the wastewater.In this dissertation, air strip was firstly used to deal with the wastewater from the penicillin plant. Experimental results show that the ascending bubbles can induce concentration difference of butyl acetate in the wastewater. However, the difference was too small to be applied.Tri-radical Oxide Phosphate and liquid paraffin were used as absorbents to investigate the possibility of recovering butyl acetate from the wastewater from the penicillin plant by solvent sublation. Results show that solvent sublation is a doable technology to deal with wastewater with dilute butyl acetate. Several absorbents were tested in the solvent sublation experiments. Results indicate that the loss of cyclohexane in the gas is unacceptable when cyclohexane is used as absorbent. It is going to be the emulsion when iso-octanol is absorbent. N-nonane and n-decane are proper absorbents especially when some iso-octanol is added to inhibit undesirable foam.The separation process can be intensified by decreasing the bubble diameter. It also can cut down the loss of absorbent in the gas.During continuous solvent sublation process, the separation efficiency is 60% when single tower is used and the separation efficiency is 90% when two towers are used.