High flux in vacuum membrane distillation for thin ceramic membranes on highly permeable supports

High flux in vacuum membrane distillation for thin ceramic membranes on highly permeable supports

We developed thin, superhydrophobic ceramic anodic alumina membranes and evaluated them in  vacuum  membrane  distillation  (VMD)  using  a  highly  permeable  support.  The  ceramic membranes have a thickness of 55 μm and pore size of 200 nm. The highly permeable support is 3 mm thick with a pore size of 1 mm. The superhydrophobic ceramic membranes displayed water contact angles and liquid entry pressure values higher than 150° and 4 bar, respectively. During VMD at 80 °C, a very high water flux of 400 kg/(m2·h) was observed, much higher than previously  reported  for  ceramic  membranes  in  the  literature.  For  comparison,  a  commercial PTFE membrane with a similar thickness (76 μm) and pore size (220 nm) was evaluated at the same  conditions  using  the  same  support  and  an  almost  identical  water  flux  of  416  kg/(m2·h) was  observed,  again  much  higher  than  previously  reported  for  this  type  of  membrane.  For  a hydrophobic  alumina  membrane  with  a  thickness  of  21  μm  and  pore  size  of  200  nm  on a traditional alumina support with a thickness of 3 mm and pore size of 2.5 μm, a quite low water flux  of  29  kg/(m2·h)  was  observed. Consequently,  we  have  shown  that  a  thin  membrane  in combination with a highly permeable support is necessary to arrive at high flux in VMD.

Keywords:  Superhydrophobic ceramic membranes; Vacuum membrane distillation; Desalination; Highly permeable support; High flux.

Authors:Nadin Al-Jariry*, Liang Yu and Jonas Hedlund Chemical Technology, Luleå University of Technology, SE-971 87 Luleå, Sweden *Corresponding author email address: nadin.al-jariry@ltu.se; Tel.: +46 920 492871

Nadin Al-Jariry*, Liang Yu and Jonas Hedlund Chemical Technology, Luleå University of Technology, SE-971 87 Luleå, Sweden

*Corresponding author email address: nadin.al-jariry@ltu.se; Tel.: +46 920 492871

Exploring the application of polymeric active layers on electrospun membranes to improve their performance for forward osmosis (FO)

Exploring the application of polymeric active layers on electrospun membranes to improve their performance for forward osmosis (FO)

Our project partner, TEKNIKER, is analyzing the promising use of electrospun nanofiber-based forward osmosis membranes in the desalination process, seeking to improve water flow and rejection performance through the implementation of advanced active layers.

The DESOLINATION project aims to develop an innovative desalination system combining direct osmosis and membrane distillation, using a draw-off solution. Forward osmosis means that seawater is extracted from the sea, the water is drawn through the membrane by the draw solution and the remaining minerals (brine) are rejected.

In recent decades, the electrospun nanofiber mat composed of numerous stacked polymeric nano-sized fibers has attracted growing attention in the fabrication of high-performance FO membranes. The unique interconnected pore structure and high porosity of the membranes can endow the composite FO membrane with a lower structural parameter, leading to the effective alleviation of ICP.

The DESOLINATION project analyzes the modification of the polymer surface to improve the performance of water treatment membranes.

Our project partner, the Technical University of Eindhoven (TU/e) is obtaining electrospun membranes of different polymers and TEKNIKER is applying polyamide thin film active layer on the electrospun membrane by interfacial polymerization, being possible to control the thickness of this active layer by adjusting the chemistries of the reactants and the conditions of the deposition and curing process.

The next step is to test the performance of the obtained membranes. Stay tuned!

Contributors: Saioa Herrero López and Miren Blanco

Join our “New developments in membranes” online workshop

Join our “New developments in membranes” online workshop

In the last days, our project member, Prof. Frank Lipnizki from the Department of Chemical Engineering of Lund University (Sweden) has had the opportunity to organise a workshop on “New Membrane Developments” with some great international speakers.

The online workshop is free-of-charge and took place on Thursday 7th of December from 9:00 – 11:00am.

The aim of the workshop is to provide an overview on recent developments of membrane with focus on water and wastewater. For this, the LUND team has invited some of the leading researchers in the field from Japan, Egypt, India and Sweden.

Membranes are the centre of all the stages of the desalination process, nanofiltration (NF) pre-treatment, Forward Osmosis (FO) and Membrane Distillation (MD) processes. In DESOLINATION, modelling and small-scale testing activities will target the optimization of all steps of hybrid membrane separations. First, NF membranes will be used to reduce fouling and scaling effect in FO. Then, the FO separation membrane will be fine-tuned to ensure control over high water flux in combination with low reverse flux from the draw to the feed solution and thus maximize the efficiency and use of the osmotic pressure difference between the seawater and the draw solution. Lastly, the MD separation membrane needs to optimize the removal of pure water from the draw solution and must therefore be adapted to the chemical and physical properties of the draw solution designed for thermal heat recovery, as well as to the temperature and pressure conditions required for the VMD recovery process.

AGENDA

09:00 – Welcome (Prof. Frank Lipnizki, Lund University, Sweden)

09:05  – Prof. Takeo Yamaguchi (Tokyo Institute of Technology, Japan): Modification of antifouling membrane surfaces

09:30 – Prof. Marwa Shalaby (National Research Centre Cairo, Egypt):  Water shortage and membrane applications

09:55 – Prof. Sabu Thomas (Mahatma Gandhi University, Kerala, India): Polysaccharide based membranes for water purification: Recent advances

10:20 – Prof. (assoc.) Naser Tavajohi (Umeå University, Sweden): A greener approach to PVDF membrane production

10:45 – Final Discussion (ALL)

11:00 – End

Meeting ID: 335 628 157 200
Passcode: y3oLXa

Modified ceramic membranes for the treatment of highly saline mixtures utilized in vacuum membrane distillation

Modified ceramic membranes for the treatment of highly saline mixtures utilized in vacuum membrane distillation

Membrane Distillation processes could enable the treatment of highly saline solutions and facilitate minimal (MLD) or zero liquid discharge (ZLD) applications. Ceramic membranes can be a robust alternative to polymeric membranes if they are chemically modified to exhibit hydrophobic qualities to prevent wetting, particularly for vacuum membrane distillation (VMD). This study found that the thin top layer of asymmetrically structured ceramic membranes is robust enough for highly saline and abrasive suspensions and that TiO2 membranes outperform Al2O3 membranes in respect to the mass transport due to their larger support pore size and lower thermal conductivity. A maximum permeate flux of 35 kg/(m2 h) with exceptionally high rejections were measured in VMD using a saline brine with a concentration of 350 g NaCl per kg H2O. Furthermore, a VMD mass transfer model was successfully adopted (based on the Dusty Gas Model) to facilitate the calculation of the mass transfer through asymmetrically structured TiO2 membranes. Model deficiencies such as the underestimation of polarization effects were discussed, and correction factors integrated accordingly. This was done to establish a mass transfer modelling fundament for asymmetrical ceramic membranes used in MD that can be extended in future works and possibly serve as a tool for membrane optimization.

https://doi.org/10.1016/j.desal.2023.116943

Authors:

  • J. Schnittger, T. Hoyer, M. Weyd, I. Voigt | Fraunhofer Institute for Ceramic Technologies and Systems (IKTS), Germany
  • Jeffrey R. McCutcheon | University of Connecticut, Department of Chemical & Biomolecular Engineering, United States of America
  • A. Lerch | TUD Dresden University of Technology, Germany
Membrane Desalination 2023 (MEMDES2023)

Membrane Desalination 2023 (MEMDES2023)

Join the DESOLINATION project partners at the 6th International Conference on Desalination using Membrane Technology in Sitges (Spain) from 19th to 22nd November 2023 to discuss the latest developments in desalination using membrane technology!

Three of our project partners Nadin Al-Jariry, Jonas Hedlund from the Department of Chemical Engineering at Luleå University of Technology, Muhammad Suleman from Lund University, and Irena Petrinić, Ross D. Jansen-van Vuuren, Thomas Luxbacher, and Hermina Bukšek from the University of Maribor, had the opportunity to present our project to leading academic researchers, scientists and engineers from the membrane desalination sector and associated industries, as well as to representatives of governmental organizations, international agencies and aid organizations.

The Univeristy of Maribor presented ‘Thermo-responsive Polyalkylene Glycol-based draw solutions for forward osmosis in seawater desalination‘ as a poster contribution. 

Together with Lund University, they also gave an oral presentation focusing on ‘Modeling forward osmosis-membrane distillation hybrid process for seawater desalination: flux prediction and process optimization‘ co-prepared by Suleman Muhammad, Al-Rudainy Basel, Petrinić Irena, and Frank Lipnizki.

Presentation extracted from the event website

Growing population, changing climate and increasing urbanisation require increasing freshwater supply and the sustainable water usage for industries and agriculture is of top priority. One of the most viable solutions is to tap from the seawater and wastewater. Membrane technologies have been established as the golden standard for desalination to address the global deficit for clean water. However, it is still expensive, which is one of the main obstacles for prevalent adoption of membranes.

Innovation is key to reduce the energy consumption and the total cost. This can be advanced by developing high performance reverse osmosis (RO) and nanofiltration (NF) membranes, robust module and process design, as well as other novel desalination technologies. We have seen promise in breaking the permselectivity trade-off using state-of-the-art nanomaterials. Biomimetic single ion channel and artificial water channel have shown exciting results in bench tests. The Sixth International Conference on Membrane Desalination 2023 (MEMDES 2023) is the dedicated forum to disseminate the cutting-edge research and development in this regard.