摘要
Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be reduced greatly.In this work,two kinds of membrane,PDMS(polydimethylsiloxane) composite membrane and Zeolite filled PDMS membrane were prepared,in which asymmetric microporous PVDF(polyvinylidenefluoride) membrane prepared with phase inversion method was functioned as the microporous supporting layer in the flat-plate composite membrane.The different function compositions of the PDMS/PVDF composite membranes were characterized by reflection Fourier transform infrared(FTIR) spectroscopy.The surface and section of PDMS/PVDF composite membranes were investigated by scanning electron microscope(SEM).The PDMS NF(nanofiltration) membranes were then applied in the recovery of hexane from soybean oil/hexane miscellas(1:3,mass ratio).The effects of pressure(0.5-1.5 MPa),cross-linking temperature and PDMS layer thickness on membrane performances were investigated.The results indicated that both two kinds of NF membranes were promising for solvent recovery,and zeolite filled in PDMS NF membrane could enhance the separation performance.
Traditional solvent recovery in the extraction step of edible oil processing is distillation,which consumes large amounts of energy.If the distillation is replaced by membrane process,the energy consumption can be reduced greatly.In this work,two kinds of membrane,PDMS（polydimethylsiloxane） composite membrane and Zeolite filled PDMS membrane were prepared,in which asymmetric microporous PVDF（polyvinylidenefluoride） membrane prepared with phase inversion method was functioned as the microporous supporting layer in the flat-plate composite membrane.The different function compositions of the PDMS/PVDF composite membranes were characterized by reflection Fourier transform infrared（FTIR） spectroscopy.The surface and section of PDMS/PVDF composite membranes were investigated by scanning electron microscope（SEM）.The PDMS NF（nanofiltration） membranes were then applied in the recovery of hexane from soybean oil/hexane miscellas（1：3,mass ratio）.The effects of pressure（0.5-1.5 MPa）,cross-linking temperature and PDMS layer thickness on membrane performances were investigated.The results indicated that both two kinds of NF membranes were promising for solvent recovery,and zeolite filled in PDMS NF membrane could enhance the separation performance.
基金
Supported by the State Key Development Program for Basic Research of China （2009CB623404）
the National Natural Science Foundation of China （20736003 20906056）
the National High Technology Research and Development Program of China （2007AA06Z317 2008EG111021）
