抄録
Separation of organic solvent by membrane is an emerging technology for the purification or separation of organic solvents. In this study, game changing OHF (Organic solvent Hyper Filtration) membranes and their applications are under development to realize the replacement from energy–consuming distillation to energy–efficient membrane process. Nano filtration (NF)–type hollow fiber OHF membrane was developed by TIPS (Thermally–Induced Phase Separation) method using solvent–resistant polymers such as nylon 6. The prepared membranes showed methanol (MeOH) permeability of > 2 LMH (L･m–2･h–1) with molecular weight cut–off (MWCO) of about 1,000 and stability for >1 month. Reverse osmosis (RO)–type organic composite OHF membrane was developed by the interfacial polymerization method. A highly cross-linked polyamide layer was prepared on a solvent resistant support membrane. The membrane showed selectivity for MeOH against toluene (TOL) in separation test using MeOH/TOL mixture. Membrane performance was Rej.＝ 65% Flux ＝ 16 LMH at 40 bar. The stability was > 2 weeks. NF–type TiO2/ZrO2 ceramic composite OHF membrane was developed using organic chelating ligands (OCL) as a pore size–fixing spacer. The membrane showed high permeability for organic solvents such as hexane (26 LMH) and MeOH (25 LMH) at 6 bar with MWCO of about 1,000 and stability of > 1 week. NF–type inorganic nanosheet OHF membrane was developed by laminating nanosheets of niobate and/or graphene oxide onto solvent resistant support membrane using chemical binders. The membrane showed relatively high MeOH permeability (11 LMH at 2 bar) and good rejection against organic dyes such as Evans blue (Mw : 960.8) with 87%.
