OVERVIEW Introduction of Nanofiltration(NF) NF Application - in - PDF document

PROGRESS OF NANOFILTRATION MEMBRANES PROGRESS OF NANOFILTRATION MEMBRANES 1 st Korea-US Nano Forum 2003. 10. 14 Kew-Ho Lee Membrane and Separation Research Center Korea Research Institute of Chemical Technology TEL) 82-42-860-7240 FAX) 82-42-861-4151 E-mail) khlee@krict.re.kr KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er OVERVIEW • Introduction of Nanofiltration(NF) • NF Application - in Aqueous system - in Non-aqueous system • NF Membranes developed in KRICT - Fouling resistant membrane - Solvent resistant membranes • Summary KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

Application range of various membrane process macro particle Particle size atomic/ low molecu- high molecu- micro particle range ionic range lar range lar range range µ m 0.001 0.01 0.1 1.0 10.0 nm 1.0 10 100 1000 10,000 Molecular 100 200 1000 100,000 500,000 weight aqueous salt colloidal silica yeast cells virus Solute bacteria metal ion proteins sugar microsolutes electrodialysis diffusion dialysis Mmebrane reverse osmosis separation nanofiltration process ultrafiltration gas separation pervaroration microfiltration dialysis KRICT Membrane & Separation Research Center NANOFILTRATION (NF) MEMBRANES – Membranes whose performance is in between those of UF and RO ( MWCO: 200-1000 g/mole) – Good rejection of multivalent ions or organic materials with low molecular weight – Low Operating pressure Suspended particles Microfiltration Macromolecules Virus Ultrafiltration Divalent Salts, Dissociated acids Small organic molecules ( 2 > nm ) Pore size < 2 nm Skin Layer < 1 µ m Nanofiltration Monovalent Salts Undissociated acids Reverse Osmosis Water KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

Schematic drawing of separation of ions Schematic drawing of separation of ions by negative nanofiltration membranes by negative nanofiltration membranes 2 – 2 – + – + – – – – – – – – – – – – swollen porous KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er Membrane modules Feed Spacer Membrane Filtrate Retentate Membrane Filtrate Filtrate Feed Retentate (a) Plate type module (b) Spiral-wound type module KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

Progress in NanofiltrationMembranes Reverse Osmosis membranes High flux & Low fouling Nanofiltration membranes RO membranes High flux & Low fouling NF membranes for NF membranes Non-aqueous solvent system Chlorine resistant NF membranes Functionalized NF membranes Preparation of composite polyamide membrane Porous ultrafiltration membrane Aqueous solution Impregnation (amine) Organic solution Immersion and reaction (acylchloride) Thin polyamide layer Composite membrane

Polypiperazineamide; NF membrane COCl COCl or HN COCl + NH COCl COCl NF-40(FilmTec); NTR-7250, NTR-729(Nitto Denko); UTC-20/50/60(Toray) Polyamide; RO & NF membrane NH 2 COCl COCl or + COCl NH 2 COCl COCl KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er High flux RO & NF membranes NH 2 Camphor sulfonic acid Diol + + Toluene sulfonicacid NH 2 Aqueous solution Significant flux enhancement due to the surface roughness increase

Low fouling RO & NF membranes High flux RO & NF membrane Coating neutral polymers or inorganic material Fouling resistance due to the surface charge blocking Solvent resistant NF membranes Cross-linked PAN UF membrane Coating silicone Kyriat weizmann; MPF series Solvent resistant against almost all solvents; Large pore (400 – 700Da)

Progress of NF membranes 100 (FilmTec , Hydranautics , SaeHan) NF90 1990 2000 80 NaCl Rejection (%) KRICT NF270 RO 60 (FilmTec ) 40 KRICT NF40 20 (FilmTec , Hydranautics , SaeHan) 0 0 1 2 3 4 5 3 /m 2 day) Flux (m 225 psi; 2000 ppm NaCl KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er EXTENSION OF NF APPLICATION Drinking Water F f o Treatment o o n d o r i e t I t n c a u d w d u o s e t r r r P y u P Fine Chemical Pharmaceutical NF Industry Industry Membranes T e x t y i l r e t I s n u d d n u I s t p r y l u P Surface Water Treatment KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

NF for Aqueous System A. Drinking and Process Water Treatment – Water softening and Pure water production – Potable Water Production_ – Surface and Ground water Treatment B. Wastewater Treatment – Oily Wastewater – Removal of Dye, VOC and Heavy Metals – Chemical plant Wastewater – Textile and Pulp Wastewater C. Food Industry – Desalting of cheese whey and sea food processing – Concentration of fruit juice – Yeast Production KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er Water Softening Acid Cartridge Feed Feed treatment filter water pump Precipitation of dissolved salts (Si, Mn, Fe) : Foulants NF Product water NF Chlorine Sulfate treatment bicarbonate Reject water KRICT Membrane & Separation Research Center

Potable Water Production Scale inhibitor Sulfuric acid Cartridge Feed filters pump Surface or ground water NF Sulfuric Mixer acid Use as a irrigation NF NF Mixer To distribute system Mixer Degasifiers (- H 2 S & CO 2 ) Chlorine KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er NF for Non-aqueous System A. Fine Chemical Industry – The separation of organometallic catalysts – The separation of small molecular weight organics (300- 1000Da) or residual reactants produced from the synthesis in an organic solvent-based systems B. Pharmaceutical Industry – The separation of pharmaceuticals (300-1000Da) synthesized in a variety of organic solvents via a multi-step synthetic route C. Vegetable Oil Industry – The recovery of solvents used in the extraction of edible oil processing – The concentration of edible oil – The separation of denaturated oil (fatty acid) KRIC T Me mbr a n e & Se pa r a t i o n R e s e a r c h Ce n t e r

N NF Membranes for Catalytic Reactor F for Non- aqueous System Methanol/Substrate Solvent resistent NF-membrane H 2 -Gas Product CSTR KRIC T Me mbr a n e & Se pa r a t i o n R e s e a r c h Ce n t e r Membrane method for vegetable oil purification Solvent (hexane) extraction Solvent (hexane) Recovery Active Carbon Water Chlorophyll,Carotenoid Removal Removal of phospholipids UF MeOH treatment Oil, Fatty acid, hexane, Other small molecules NF or RO Crude Oil Dewaxing MeOH UF or MF Odoring material Hexane N 2 Odor NF Deodorization (N 2 ) VP Fatty acid Hexane + N 2 Refined Oil KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

NF membranes studied in KRICT 1. Polyamide NF membranes (interfacial polymerization) NF-90 : > 90% rejection of NaCl; underground water treatment NF-70 : > 70% ; underground water treatment NF-40 : > 40% ; surface water treatment NF-20 : > 20% ; surface water treatment Development trend : High flux and low fouling 2. Organic solvent-resistant NF membranes Low swelling and high flux in organic solution High separation of small molecular solute in organic solution 3. PVA & Integrally skinned NF membranes Low fouling and chlorine resistant Fouling-Resistant NF Membrane • Fouling A. Foulants – Humic acid – Proteins – Colloids – Mineral salts – Surfactants – Silica B. Problems – Increasing operation and maintenance costs – Deteriorating membrane performance – Shortening membrane C. Properties influencing fouling – Surface structure (roughness, pore size) – Electrokinetic characteristics ( ξ -potential) – Chemical property (hydrophobic-hydrophilic interaction)

PVA-coated polyamide composite membrane – Polyamides Piperazine & m-phenylene diamine Trimesoyl chloride – Poly(vinyl alcohol) Poly(vinyl alcohol) 0.05 wt% Glutaraldehyde – Interfacial & Dip coating Method – Support membrane Polysulfone MWCO 50kDa – Other NF membranes NF 70 NF 70/PVA PVA Polyamide Support Membrane KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er Change of membrane performance by PVA coating Change of membrane performance by PVA coating Rejection rate (%) PWF (m 3 /m 2 day) PEG 200 NaCl PA 2.9 60 8 PA/PVA (1) 2.6 72 13 NF-70 1.7 81 75 NF-70/PVA (3) 1.4 88 83 25 ° C; 200 psi KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er

Neutral polymer- or nano particle-coated polyamide composite membrane – Surface water treatment after microfiltration 1.0 0.9 NF-20 Relative flux (F t /F 0 ) Fouling resistant NF 0.8 0.7 0.6 0.5 0 10 20 30 40 50 60 70 80 90 100 110 Operating time (hr) ξ -potential of PVA-coated NF membranes ξ -potential of PVA-coated NF membranes 30 NF-70 20 NF-70/PVA(3) 10 PA 0 Zeta potential (mV) PA/PVA -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 2 3 4 5 6 7 8 9 10 11 pH Electro-phoretic method; pH 7.0; 0.01M NaCl KRIC T Membr a ne & Sepa r a t ion Resea r c h Cent er