Ceramic nanofiltration membranes of enlarged membrane area for water application results of project CeraWater

Transcription

1 Ceramic nanofiltration membranes of enlarged membrane area for water application results of project CeraWater Marcus Weyd, Volker Prehn 1, Petra Puhlfürß, Hannes Richter, Ingolf Voigt 1 Rauschert Kloster Veilsdorf GmbH CeraWater, Fouling resistant ceramic honeycomb nanofilters for efficient water treatment Fraunhofer Gesellschaft Membrane background at Fraunhofer IKTS Project goals Development of support and NF membrane Summary + Outlook

2 The Fraunhofer-Gesellschaft in profile Locations in Germany 67 institutes More than 22,000 employees IKTS with branches in Dresden and Hermsdorf Ceramic institute with strong focus on ceramic membranes Bremerhaven Oldenburg Bremen Itzehoe Lübeck Hamburg Rostock Hannover Potsdam Berlin Teltow Braunschweig Magdeburg Cottbus Oberhausen Paderborn Hall Dortmund Schkopau e Leipzig Duisburg Kassel Leuna Schmallenberg Jena Dresden St. Augustin Aachen Freiberg Euskirchen Gießen Erfurt Hermsdorf Chemnitz Wachtberg Ilmenau Institutes and research institutions Other locations Darmstadt Würzburg Bayreuth Erlangen Bronnbach St. Ingbert Kaiserslautern Fürth Nürnberg Saarbrücken Karlsruhe Pfinztal Ettlingen Stuttgart Straubing Freising Freiburg Augsburg Garching München Oberpfaffenhofen Kandern Prien Efringen- Holzkirchen Kirchen

3 Background in terms of membrane

4 State of the art - Ceramic NF-membranes inopor nano History : Development Al 2 O 3 -supports, MF- and UF-membranes : Development of NF-membranes (HITK/IKTS + RKV) : Pilot production of membranes on a semi-technical level (inocermic), first pilot membrane filtration plant (25 m²) 2005: Membrane production in full technical scale (inocermic + RKV) 2006: Foundation of inopor GmbH

5 State of the art - Ceramic NF-membranes inopor nano Morphology Material: amorphous TiO 2 Membrane thickness: 50 nm Pore size: 0.9 nm Open porosity: 30 % Temperature stability: 350 C Pressure stability: 60 bar High chemical stability Max. membrane size 19 channel tube (0.25 m²) W & Au TiO 2 ZrO 2 TiO nm

6 State of the art - Ceramic NF-membranes inopor nano Retention behavior Retention [%] Cut-Off 450 g/mol Molecular weight [g/mol] 0.9 0,9 nm TiO2 2 NF-Membran membrane 5 nm TiO2 2 UF membrane Membran

7 State of the art - Ceramic NF-membranes inopor nano Examples of application Waste water cleaning Waste Removal water of dye cleaning Decolouring Cleaning of inutec Cleaning Retention of of inutec catalysts Retention Separation of of catalysts aroma special properties of ceramic membrane opened field of application in several processes (very) large scale applications are hindered by high specific membrane costs ( /m²) Main reason: low membrane area per element

8 Objectives

9 Project overview Improve the efficiency of high performance water purification by ceramic membranes by: Strong increase of membrane area of ceramic NF membranes The CeraWater consortium consists of 8 European organizations (RTD, Large enterprises, SME) from 4 countries Grant agreement No Improve anti fouling properties Develop process schemes for treatment of different waters

10 One focus: Complexity of Membrane support Pressure drop of permeate increases with complexity of support (and number of intermediate layers and decreasing pore size) best combination?

11 Results

12 Influence of pore size and intermediate layers Results of simulation Membrane support pore size [µm] [%] Porosity Idea Results Standard OK Reduce layers Pressure drop too high Reduce layers Pressure drop much too high Even further larger pores would be beneficial for complex geometries Special support material development necessary (4.5 µm pores)

13 Intermediate geometry, 3 µm support, NF coating 163 CT Membrane area 1.3 m² Permeance 33.8 l/m² h bar Membrane geometry suitable for NF Choosen for development of NF coating

14 Developed membrane, 3 µm support, NF coating HCNF2a Membrane area > 4 m² Increased channel diameter Permeance 36 l/m² h bar (higher than 163CT) Membrane geometry suitable for NF Chosen for development of NF coating

15 FEM-Model Mechanical 20bar pressure inside Assumption: plain strain Stress distribution is constant along the length of structure

16 Results HCNF2a 2 nd design Mechanical 20bar pressure inside 1 st principal stress (left), enlarged view of deformation (right)

17 Results Different geometries Mechanical behavior; 20bar internal pressure loading Support shape P1 [MPa] Ch. [mm] Wall th. [mm] Burst pr. [bar] 19-ch tube ch tube HCNF1/163CT ? HCNF2a (1) ? HCNF2a (2) ? No significant relation to ch. diameter and wall thickness Stress reduction of 28 % from HCNF2a 1 st to 2 nd design Need for design improvement of HCNF2a at selected outer channels Size, shape (radius) in accordance with requirements of extrusion

18 Progress of membrane coating Hurdles and tasks Lower bubble point of layers on new supports Less retention on new supports Worse layer quality on new supports Tasks and activities Variation of support geometry and support material Variation of coating technique and medium Analysis of membranes at different steps of membrane synthesis Selection of best and worst samples Geometry retention Øretention flux Øflux [No. of Ch.] [%] [%] [l/m²hbar] [l/m²hbar] Reasons 61(amongst 57 others): different 27 suction behavior 61 and different 53 transport of 28coating media in channels 45 of different shape inner channel outer channel

19 Progress of membrane coating - COD retention Comparison NF on 3 µm and new support Support pore retention Øretention flux size [%] [%] [l/m²hbar] A - 3 µm A - 3 µm A - 3 µm A - 3 µm Batch 1 Øflux [l/m²hbar] CW µm CW µm CW µm Batch 2 CW µm CW µm CW µm Higher retention and flux for CWsupported 61 CT New CW-support is not the problem for NFmembrane preparation

20 Progress of membrane coating - SEM on HCNF2a big channel small channel straight In all cases smooth and defect free membranes small channel curve

21 Summary Membrane geometries of enlarged membrane were developed Membrane supports of high mechanical stability were obtained adaption of NF coating on new support and support material NF layers of high quality were applied on new support material Outlook: Good conditions for further enlargement of membrane area High quality NF coating on final support Demonstration of membranes and anti-fouling coating in water treatment

22 Research field Environmental and Process Engineering Financial support is gratefully acknowledged (Grant agreement no: ) Thank you for your attention!