Preparation And Modification Of EC Pervaporation Membrane For Gasoline Desulfurization

Pervaporation is a non-hydrogenation technology,which has the advantages of deep desulfurization,no loss of octane number,and less investment cost etc.,is considered to be a promising gasoline desulfurization method.However,this technology has not realized it’s industrialization because of the restrict in material development.In this study,the selection and modification of the membrane material and the process optimization were investigated.Using polyvinyl fluoride（PVDF）as the matrix and ethyl cellulose（EC）as the separation subject,the reaction was carried out under ultraviolet radiation with1,6-Hexanediol diacrylate（HDDA）and trimethylpropane triacrylate（TMPTA）.Through the Infrared and Scanning Electron Microscopy（SEM）characterization of EC crosslinked membrane we found that the crosslinking reaction was successful and great changes have taken place after crosslinking.The preparatio n process optimization of crosslinked EC pervaporation membrane were showed as follows:solids content 18%,a crosslinking agent content of 22%,the optimum membrane formation temperature of 50°C;the optimum desulfurization temperature of 80°C,then under the optimal condition the flux is 2.434kg/（m²·h）and sulfur enrichment factor is 4.367;In this study two crosslinking agents were used in the experiment,under the same conditions,the order of membrane flux is as follows:HDDA>TMPTA,the sulfur enrichment factor is in the order of:TMPTA>HDDA.Because ofπ-d complexing,this study introduced AgNO₃ to EC membrane.Compared with crosslinked EC membrane,the flux of the hybrid membrane was lower and the sulfur enrichment was higher at low temperature.The Electron Microscope Scanning showed that AgNO₃ evenly dispersed in the membrane,no obviously agglomeration.According to the similar disso lve mutually theory,this study introduced acryloyl chloride to EC.The Attenuated Total Reflection Infrared Spectrogram showed that C=C and C=O appeared in the grafting products,acryloyl chloride has been successfully grafted on the EC;From the X-Ray Diffraction we found that the crystallinity of the graft polymer was decreased after grafting;The desulfurization performance of grafted EC membrane was compared with the crosslined membrane and the hybrid membrane.