How do ceramic membranes work?

Clean water is a scarce resource, and ceramic membranes are vital in solving this massive global problem. The membranes make up a liquid filtration technology heavily applied in industrial environments as ceramic membranes deliver high-quality and high-endurance liquid filtration. Feedwater enters the ceramic membranes, and the outcome is separated, permeate, and concentrate. However, this process has many more details, so let us dive into how ceramic membranes work.

Ceramic membranes can remove multiple objects, such as suspended solids, oil droplets, oil emulsions, particles, and bacteria. Likewise, ceramic membranes can purify and clean fluids at different levels depending on the specific filtration requirements, making membranes highly relevant to numerous tasks in various industries.

Let us dive into the water filtration process.

Water Filtration

In water filtration, we operate within two different filtrations ranges, which are denoted microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO), where the latter is the finest.

Microfiltration (MF) and ultrafiltration (UF) are known as low-pressure membrane filtration. MF and UF are filtration processes in which contaminated waste streams pass through the membrane that retains suspended solids, including colloids and viruses. These particles are larger than the membrane’s pore size, which results in filtered and purified liquid.

The particle size retained by the membrane is defined by the membrane’s pore size (0.1 microns to 0.01 microns for ultrafiltration and larger than 0.1 microns for microfiltration).

Nanofiltration involves the potential separation of salts and is thereby closely linked to reverse osmosis. The membrane’s pore size determines within what filtration range a membrane filters. Still, the membranes within nanofiltration and reverse osmosis are sensitive. Therefore, a microfiltration or ultrafiltration is often recommended before nanofiltration or reverse osmosis to handle the separation of larger objects first. This will protect the pump, reduce fouling, and ensure a longer operating time and improved OPEX.

See the below video to understand what a ceramic membrane is, how it works, and the massive difference between the different filtration ranges.

Produced Water For Reuse (Onshore) Liqtech

The Filtration Process

To filter industrial liquids, feedwater, which is the liquid to be filtered, enters the ceramic membranes.

A feed pump triggers the filtration process by generating pressure, making the feedwater move through the membranes. The permeate will start to move through the membrane structure as a filtered liquid. Firstly, the permeate will move through the silicon carbide membrane layer. Secondly, the permeate will move through the membrane substrate structure, which is easier to pass through as this layer is made of larger silicon carbide grains than the membrane’s structure. The permeate will end up in a permeate tank, ready for further usage.

Meanwhile, the concentrate, which is concentrated feedwater, is sent to subsequent processing. As this is concentrated feedwater, it is much dirtier than the actual feedwater. The permeate and the concentrate are now ready for further processing, reuse, or recycling. The permeate can be reused as it is filtered. The concentrate can be reused as it may contain essential unexploited resources, which can be valuable assets within other production processes.

Because of the above, a water filtration system can be considered a tightly coupled system, where all parts play a significant role in water filtration. The feed pump initiates the filtration, but the filtration occurs within the ceramic membranes.

Liquid Filtration Is the Lever to a Sustainable Future

Within liquid filtration, you can optimize your operation by utilizing all your resources to the fullest, as you can separate permeate from concentrate. This can lead to cost savings and process optimization within other production areas. But more significantly, liquid filtration is the lever to a sustainable impact and supports a green transition for an improved future.