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Enabling Platform Technology

Our patented membrane forming processes and formulations comprise a robust and enabling platform technology that allows for the development of products and processes that address various market needs in the following industries:

  • Natural Gas Upgrading
  • Biofuels
  • Water Purification
    • Water Desalination
    • Membrane Distillation

      Membrane distillation (MD) is an emerging technology for separations that are traditionally accomplished via conventional distillation or reverse osmosis. As applied to water desalination, MD involves the transport of water vapor from a saline solution through the membrane. PDMS (Silicone) has a high permeability to water vapor thereby facilitating the transport of water vapor across the membrane while rejecting the salt and other solutes. Since liquid does not penetrate the hydrophobic membrane, dissolved ions are completely rejected by the membrane. MD has a number of potential advantages over conventional desalination including low temperature and pressure operation, reduced membrane strength requirements, compact size, and 100% rejection of non-volatiles.

      MD could be used effectively in the Arabian Gulf States to desalinate the brines from existing thermal desalination facilities. This can leverage the latent heat of the brines while harnessing low-grade waste heat from power plants or other industrial facilities, to lower the environmental impact from discharging warmer streams into the sea. The capacity of an existing desalination facility may also be increased without incurring new capital and operating costs associated with seawater intake infrastructure and pretreatment facilities. The end result would be an overall higher product water recovery rate from the existing desalination facility.

      Much research has been conducted with micro porous hydrophobic membranes or composite membranes composed of a porous substrate skinned with a thin PDMS layer. Results suggest that dense PDMS hollow fiber contactors would be ideal for membrane distillation to be economically competitive:

      Sweeping Gas Membrane Desalination Using Commercial Hydrophobic Hollow Fiber Membranes
      SAND 2002-0138, Sandia National Laboratories. Lindsey R. Evans, James E. Miller

    • Water Degassing
  • Energy
  • Pollution Control / Organic Vapor Recovery
  • Water Conditioning
    • Iron Removal
  • Biotechnology
    • Bioreactors

      Silicone (PDMS) membranes have been used effectively in bioreactors to control dissolved gases in the media or broth in order to maintain bio-processes viable and high production rates. Because the membrane is permeable it enables the transfer of gases and vapors into and out of the bioreactor's media for effective management of gases. Our membrane technology has been used in applications such as oxygenation and gas control in bioreactors as well as in transfer of pollutants to microorganisms suspended in a liquid medium. The following articles describe using silicone membranes for this purpose.

      Membrane bioreactors for waste gas treatment
      Journal of Biotechnology Volume 59, Issue 3, 3 January 1998, Pages 155–167
      Martine W Reij, et al.

      This review describes the recent development of membrane reactors for biological treatment of waste gases. In this type of bioreactor gaseous pollutants are transferred through a membrane to the liquid phase, where micro-organisms degrade the pollutants. The membrane bioreactor combines the advantages of membrane devices with the clean technology of biological air purification. Two types of membrane materials can be used for gas–liquid contact: hydrophobic microporous material and dense material, such as silicone rubber. Microporous material generally has a higher permeability, but dense membranes can be advantageous in the case specific selectivity is required. Biomass is generally present as a biofilm on the membrane, but may also be suspended in the liquid phase. In a number of cases the reactor performance appears to be hampered by an unstable biofilm performance and/or by clogging of the liquid channels due to excess biomass formation. So far, membrane bioreactors for waste gas treatment have only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, we expect membrane bioreactors to be useful tools in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with the conventional methods for biofiltration.

      Bubble-free aeration using membranes: mass transfer analysis
      Journal of Membrane Science Volume 47, Issues 1–2, November 1989, Pages 91–106
      Jean-Luc Bersillon, et al.

      The mass transfer characteristics of silicone rubber hollow fibres for the oxygenation of water were studied. A resistance-in-series model with two resistances, the membrane and the liquid film resistances, was used to describe the oxygen transfer process. Data from the literature indicate that the liquid film resistance is normally larger than the membrane resistance when a polymer (such as silicone rubber) with a high oxygen permeability is used. A new module configuration, designed to decrease the liquid film resistance, was evaluated experimentally and compared with the conventional inside flow configuration. The module was very efficient in reducing the liquid film resistance. Experiments were also conducted to study the effect of oxygen partial pressure, the use of air or oxygen, the gas flow regime and the presence of surfactant on the efficiency of oxygen transfer.

    • Fermentation
    • Algae Production
  • Health Care

Many of these markets have been served with silicone (PDMS) membranes configured as spiral wound flat sheets. Our hollow fiber membrane configuration provides many advantages over the spiral wound format, including up to ten times higher membrane area density per volume, no porous substrate to impede gas transfer or limit compatibility, and substantially lower cost per unit area. Moreover, our patented forming process allows for incorporating molecular sieves such as zeolites to form mixed matrix membranes tailored for specific separation processes. We have also developed proprietary siloxane based formulations which have up to ten times the modulus of our standard PDMSXA formulations, and which enable thinner membranes that can tolerate higher trans-membrane pressures and provide higher permeances.

We are actively seeking strategic partners with well established presence in these markets to collaborate on scaling-up and developing products incorporating our membrane technology. If your organization is interested in providing solutions in one or more of these industries using our patented technology, Contact us or call us at +1 (734) 769-1066 x21 to discuss opportunities.