Re: Membrane to remove water from oil/water/methanol mixture?

Sinclair,

Yes there are a few membranes that would separate oil from water, but I am 
not sure about separating the methanol from water using a membrane.  Due 
to the similarities between water and methanol in terms of polarity, etc in 
comparison with oil.  A quick search in the internet will reveal various 
approaches to water separation from oil using membrane.  Here is an 
examples of a novel one: 
 http://www.azom.com/News.asp?NewsID=14627


Separation of oil/water emulsion using Pluronic F127 modified 
polyethersulfone ultrafiltration membranes 

Separation and Purification Technology
Volume 66, Issue 3, 7 May 2009, Pages 591-597 

Wenjuan Chena, Jinming Penga, Yanlei Sua, Lili Zhenga, Lijun Wanga and 
Zhongyi Jiang, a, 

aKey Laboratory for Green Chemical Technology, School of Chemical 
Engineering and Technology, Tianjin University, Tianjin 300072, China


Received 10 December 2008;  revised 14 January 2009;  accepted 16 January 
2009.  Available online 24 January 2009. 

Abstract
Polyethersulfone (PES) membranes modified by the amphiphilic copolymer 
Pluronic F127 were applied to the separation of oil/water emulsion. Due to 
the enhanced surface hydrophilicity, all the PES/Pluronic F127 membranes 
exhibited higher permeate flux and better antifouling property compared 
with the control membrane. When the weight ratio of Pluronic F127 to PES 
(WF127/WPES) in the membrane casting solution was increased from 0 to 20%, 
the flux of oily feed solution was increased from 42.77 to 82.98 L/m2h 
with 100% oil rejection. There was no flux recovery for all used membranes 
when being washed with pure water. However, the flux recovery ratio could 
be increased to 93.33% when washing with sodium dodecylsulfate (SDS) 
solution. It was proposed that the presence of surfactant prevented the 
deposited oil droplets from coalescing with each other and spreading on 
membrane surface (including membrane pore surface).

Keywords: Oil/water emulsion separation; Ultrafiltration membrane; 
Polyethersulfone; Pluronic F127; Membrane washing