What is a Ceramic Membrane?

Ceramic membranes represent a revolutionary filtration technology that meets many and-user demands of today and the future by providing current and forthcoming compliance with environmental regulations and sustainable production. In addition to fighting the global problem of clean water by enabling water reuse, recycling, and recovery, ceramic membranes also contribute to low energy consumption, high capacity, and a small footprint. Let us dive into the details of a ceramic membrane.

Ceramic membranes are the most crucial part of a water filtration system.

In these systems, membranes are stored in a housing. The liquid is filtered as the ceramic membranes filter fluids by removing, e.g., suspended solids, oil droplets, oil emulsions, particles, and bacteria. Ceramic membranes can purify liquids at different levels depending on the specific needs and requirements, making ceramic membranes relevant for several tasks in various industries.

Membranes can be used for harsh environments, such as:

Still, they are also applicable in environments demanding high sanitation standards, such as:

Ceramic membranes can be utilized for pre- and post-treatment depending on various processes and filtration requirements.

Dimensions & Filtration Principles

A ceramic membrane can be developed on supports that are in various forms and dimensions. Based on more than 20 years of experience, LiqTech has thoroughly constructed unique tubular membranes with different pore sizes and multiple dimensions.

These various designs enable two different filtration principles, meaning there is an ideal method regardless of the respective liquid to be filtered. The two filtration principles are respectively called the inside-out and outside-in principles. The inside-out principle comprises crossflow filtration, semi-dead-end filtrations, and dead-end filtration, while the outside-in filtration principle comprises submerged modules for vacuum-driven filtration. Read more about the inside-out and the outside-in filtration principles here.

Ceramic Membrane Offering

Membrane Filtration Microtechnology Liqtech

Materials

Ceramic membranes are made of inorganic materials, such as silicon carbide, zirconia oxide, alumina, or titania. With over 20 years of research and development experience within ceramic membranes, we have based our patented ceramic membranes on silicon carbide, abbreviated SiC. Silicon carbide is the second hardest material globally, only beaten by diamonds. A solid material secures a high-quality and robust membrane with long working service life. Silicon carbide is a semiconductor that contains silicon and carbon. SiC is linked to unique advantages such as providing a porous support structure, which only filtered water can permeate while impurities are rejected. Besides that, SiC provides high flux, chemical resistance in all pH values from 0-14, and thermal resistance up to 800°C. Read more about the advantages of the strong material silicon carbide here.

A membrane can have one or several parallel flow channels extending through the whole element in the porous support structure.

A special coating is put on the walls of the membrane's flow channels to obtain all the desired effects of a ceramic membrane. The coating material contains silicon carbide and is dried and sintered at a high temperature in an inert atmosphere. The coating layer provides the membranes with ruggedness and durability and determines the membranes’ flow channel pore size and water flux. Read more about the membrane production process here and the membrane coating here.

Liquid Filtration

Liquid filtration consists of various processes. A pump ensures that the feed stream is exposed to pressure from one end of the membrane, which will make the liquid flow through the flow channels of the membrane. The liquid that flows through the membrane barrier is called permeate. The permeate flows towards the membrane’s outer barrier and is removed continuously as a filtered liquid. Suspended solids, oil droplets, oil emulsions, particles, and bacteria cannot permeate the barrier and are thus rejected. All rejected elements are called concentrate. The concentrate flows through the membrane flow channels and ends up at the other end of the membrane. Read more about the liquid filtration process here.

Membrane Cleaning

As the liquid is filtered, visible and invisible objects such as particles, oil, and biomass from the feedwater will eventually start to foul the membranes. Complete fouling is avoidable with a three-process cleaning procedure. The cleaning procedure can occur either manually, semi-automatically, or automatically.

The first process is a crossflow, which cleans the membranes with feedwater due to the shear force on the membrane surface. The process happens most frequently.

The second process is a traditional backwash. A backwash is generated by a backwash pump, flushing water back through the membrane pores from the opposite direction.

The third process is a chemical cleaning-in-place, also abbreviated as CIP. Cleaning-in-place involves chemicals, heat, and water to clean all the membranes without dismantling the water treatment unit. CIP is an efficient method of cleaning the membranes quickly and effectively, which is critical in liquid filtration processes. An effective cleaning process ensures low downtime of the whole water filtration system, which provides a more efficient and cost-effective operation.

Curious about how a ceramic membrane is cleaned? Learn more about here.

UV C LED Disinfection Of Water, Air And Surfaces

Sustainable Standards of the Future

Besides the abovementioned benefits and features, ceramic membranes can reduce energy consumption, reduce water consumption for backwash, increase capacity, and fit into a small footprint. This secures compliance with current and future environmental regulations and more sustainable, efficient, and cost-effective operations. Thereby, ceramic membranes enable other industries to grow while meeting the sustainable standards of the future.