Ceramic Membrane Technology

Learn more about our SiC technology

Our Ceramic Membrane Technology

Our SiC filters are manufactured with a ceramic membrane based on our unique, patented silicon carbide membrane technology. We make both the substrate (honeycomb) and the membrane (the part that accomplishes the filtering) solely from the durable and long-lasting material, silicon carbide. This gives our membranes some unique advantages compared to traditional ceramic and polymeric membranes.

With our SiC technology, the ceramic membrane carrier is based on the so-called honeycomb or monolith structure, as shown in the picture.

Several parallel flow channels extend through the element in the porous support structure. The feed stream is introduced under pressure at one end of the element and flows through the channels during processing. The portion of the liquid passing through the membrane, known as the permeate, flows into the porous structure of the element. The combined volume of permeate from all flow channels moves toward the outer shell of the monolith support and is removed continuously.

See our silicon carbide filter products

Ceramic Membrane Layer

Ceramic membrane technology is perfect for liquid filtration and diesel particulate filters (DPFs) for the control of soot exhaust particles from diesel engines.

The actual membranes are formed on the walls of the flow channels extending through the porous ceramic structure of the element by slip casting a specific coating material of ceramic particles according to the desired pore size and distribution.

The coating material containing the silicon carbide is dried and sintered. This process ensures a strong bond with the carrier material and provides the silicon filter membrane with its unique ruggedness and durability. Several layers may be deposited on top of each other in order to reach the desired combination of membrane pore sizes and water flux.

See the picture for SiC membrane layers on top of a SiC carrier.

See Video Explanation of Membrane Layers

Unique Properties with Endless Opportunities

Features & Benefits

Perfect for harsh applications

  • Highest flux for any membrane material
    The high flux is reached through high membrane porosity (~45%) and a material with a low resistance to transport of water and a low contact angle. Reduce your footprint and system costs (fewer pipes, valves, etc.)
  • Chemically inert pH 0-14
    No limitations, fast cleaning, reduced downtime during Cleaning in Place (CIP), filtration of acids and alkalis.
  • Thermally resistant up to 800°C
    Steam cleaning, more efficient chemical cleaning, and high-temperature applications.
  • Hydrophilic material (water-loving)
    Unmatched performance in oil/water separation.
  • Isoelectric point pH 2.4
    Unmatched performance in oil/water separation – To some extent reduces fouling, easier to clean.
  • Extremely hard & durable material 2930 +/- 80 kgf/mm³ (Vickers scale)
    Robust and long lifetime, less downtime and maintenance, stable operation, cleaning with shock pulses, and hard material.
  • Abrasive Feeds
    Our silicon filter membranes are extremely durable, so abrasive feeds won’t damage the membrane.
  • Low power usage and low pressure
    Our membrane systems typically use around 7 psi or 0.5 bar of pressure (depending on the feed water), so you save money on pumps and energy
  • Long membrane life
    The silicon filter membrane is extremely durable (second hardest material in the world).
  • Low operational cost, low total cost of ownership
    With very infrequent membrane replacement, low power usage, and moderate chemical usage, the operational costs of membrane systems are low, and the total cost of ownership and low maintenance profile is very favorable compared to other systems.

Applications Areas

Silicon carbide ceramic filters are ideal for the treatment of:

  • Wastewater
  • Produced water
  • Pre-RO filtration
  • Polymer flooded streams
  • Control of soot exhaust particles
  • ... and many more

Ceramic vs. Polymeric Membranes

Ceramic membranes and polymeric membranes are the main types of membranes. They are both filtration media used for water and wastewater treatment. Still, there are significant differences between the two types of membranes.

Ceramic membranes are produced of inorganic materials such as silicon carbide, titania, or zirconia. Polymer membranes are made of organic materials such as polysulfone, polyethylene, or polyacrylonitrile.

Polymeric membranes have previously been preferred due to their low cost and ease of scalability. Yet, this type of membrane suffers from low mechanical, chemical, and thermal stability. Moreover, it cannot withstand frequent and aggressive chemical cleaning, crucial to maintaining excellent hygiene standards in many industries. Thus, there is a limitation to which sectors and water and wastewater treatment tasks polymeric membranes can withstand. Consequently, more enterprises replace polymeric membranes with ceramic membranes as these possess advantageous properties, enabling them to withstand aggressive fluids.

Our ceramic membranes can withstand all types of liquids regardless of temperature and pH. They deliver consistent permeate quality regardless of the feedwater. As they are made of silicon carbide (SiC), which is the second hardest material globally, they are extremely durable. The membranes can go on and on, and you do not need to worry about membrane replacement.

Comparison of Different Membrane Materials

Silicon carbide is the best material for filtration applications

Characteristics Alumina (Al2O3) membrane Titania (TiO2) membrane Zirconia (ZrO2) membrane-HTM Silicon carbide (SiC) membrane
Chemical resistance +++ +++ ++++ +++++
Thermal stability ++ ++ ++++ +++++
Mechanical strength ++++ ++++ +++++ +++++
Hydrophilicity + ++ ++++ +++++
Permeability ++ ++ +++ +++++
Resistance to fouling + ++ +++ ++++
Lifetime ++ ++ +++ ++++
Crossflow Filtration Principle Liqtech

Filtration Principle (inside-out)

Crossflow and dead end filtration (inside-out)

Our range of CoMem and CoMem Conduit tubular membrane filters are designed for crossflow filtration of liquids with high amounts of suspended solids, oil, algae, bacteria, etc.

Crossflow filtration is a filtration method where the feed flow is tangential to the surface of the tubular membrane filter in order to sweep rejected particles and solutes away. The feed fluid is separated into two product streams, which are respectively denoted permeate and retentate. The permeate is depleted of the rejected particles, and the retentate (or waste/concentrate) is enriched in those particles.

The advantage of using crossflow filtration is the superior handling of liquids with high solids content, as the retained particles are being continuously removed from the ceramic membrane surface. In addition to the cleaning mechanism of crossflow filtration, the tubular membranes can be cleaned with a traditional backwash, back pulse, and/or periodic chemical cleaning.

See Inside-out filtration Illustration

Dive Even More Into Ceramic Membranes

Academic institutions, government organizations, and R&D units worldwide use ScienceDirect to shed light on new research and insights to inspire innovative thinking. We are in the lucky position that some of our employees have published several ceramic membrane articles on ScienceDirect to support creative thinking, more innovative teaching, learning, and research – please have a look.

  1. Ultrafiltration Membranes

    Hybrid UF Membranes

    Corrosion-resistant ZrO2/SiC ultrafiltration membranes for wastewater treatment and operation in harsh environments.

  2. Ceramic Membranes For Liquid Filtration

    Ceramic membrane roadmap

    A roadmap for the development and applications of silicon carbide membranes for liquid filtration: Recent advancements, challenges, and perspectives.

  3. Sic Membranes

    SiC Membranes

    Enhanced fabrication of silicon carbide membranes for wastewater treatment: From laboratory to industrial scale.

Talk to a Membrane Expert

Do you need more information about Liqtech membranes, please do not hesitate to contact us.

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