Molecular separation with organic solvent nanofiltration: a critical review.

Over the past decade, solvent resistant nanofiltration (SRNF) has gained a lot of attention, as it is a promising energy- and waste-efficient unit process to separate mixtures down to a molecular level This critical review focuses on all aspects related to this new burgeoning technology, occasionally also including literature obtained on aqueous applications or related membrane processes, if of relevance to understand SRNF better An overview of the different membrane materials and the methods to turn them into suitable SRNF-membranes will be given first The membrane transport mechanism and its modelling will receive attention in order to understand the process and the reported membrane performances better Finally, all SRNF-applications reported so far – in food chemistry, petrochemistry, catalysis, pharmaceutical manufacturing – will be reviewed exhaustively (324 references)

Solvent resistant nanofiltration: separating on a molecular level

Effects of polyether–polyamide block copolymer coating on performance and fouling of reverse osmosis membranes

High performance organic solvent nanofiltration membranes: Development and thorough testing of thin film composite membranes made of polymers of intrinsic microporosity (PIMs)

State of art of the application of membrane technology to vegetable oils: A review

The separation of different vegetable oil/solvent mixtures with two types of nanofiltration membranes was studied. One type had a PEBAX [poly(amide-b-ether) copolymer] top layer, and the other had a cellulose-type top layer. These membranes were stable in acetone, ethanol, 2-propanol, and hexane, all important to the oleochemical industry. Permeabilities were highest for acetone, ±140 L/m2 · h · MPa, and lowest for hexane, which had negligible flux at 2 MPa. Permeabilities decreased with increasing triglyceride or free fatty acid (FFA) concentration. Rejection of triglycerides was constant over the concentration range tested, about 80–95%±5%, depending on the type of membrane used. These properties make membranes applicable for separating triglycerides from acetone by enhancing acetone recovery. Deacidification of triglycerides and FFA mixtures was possible (e.g., fatty acids were retained less than triglycerides). The permeate consisted almost entirely of fatty acids in acetone, and only small traces of triglycerides were found. This makes it feasible to selectively remove the fatty acids and reduce loss of triglycerides normally associated with deacidification.

Anne Marie Krosse

Papers

Acetone-stable nanofiltration membranes in deacidifying vegetable oil