Ceramic membranes, also known as inorganic ceramic membranes, are asymmetric membranes formed by a special process using inorganic ceramic materials. Ceramic membranes are divided into two types: tubular ceramic membranes and flat ceramic membranes. The tubular ceramic membrane is densely packed with microporous walls.
Under pressure, the raw material flows inside or outside the membrane, and small molecules (or liquids) pass through the membrane, while large molecules (or solids) are retained by the membrane, thus achieving the purpose of separation, concentration, purification and environmental protection. According to a certain membrane pore size range, the permeation rate is different when the molecular diameter of the permeated material is different. With the pressure difference between the two sides of the membrane as the driving force, the membrane is a filtration medium, and under a certain pressure, when the liquid flows across the membrane surface, only water, inorganic salts and small molecules are allowed to pass through the membrane, while large molecules such as suspended matter, gum and microorganisms in water are prevented from passing through.
Ceramic membranes have many advantages such as high separation efficiency, stable effect, good chemical stability, acid and alkali resistance, organic solvent resistance, bacteria resistance, high temperature resistance, pollution resistance, high mechanical strength, good regeneration performance, simple separation process, low energy consumption, easy operation and maintenance, long service life, etc. They have been successfully applied in many fields such as food, beverage, plant (medicine) deep processing, biological medicine, fermentation, fine chemical industry, etc. They can be used for process It can be used for separation, clarification, purification, concentration, sterilisation and desalination in the process.
Ceramic membrane is one of the inorganic membranes, which is a solid membrane material in membrane separation technology, mainly made of inorganic ceramic materials such as alumina, zirconia, titanium oxide and silicon oxide of different specifications as support body, coated on the surface and fired at high temperature. Commercial ceramic membranes usually have a three-layer structure (porous support layer, transition layer and separation layer) and are asymmetrically distributed, with pore sizes ranging from 0.8nm to 1μm and filtration accuracies ranging from microfiltration, ultrafiltration and nanofiltration.
Depending on the support body, the configuration of ceramic membranes can be divided into three types: flat, tubular and multi-channel. Due to their resistance to acids and bases, high temperatures and chemical stability in extreme environments, and due to the small pore size of commercial ceramic membranes (usually less than 0.2μm), they can successfully achieve molecular-level filtration, and are therefore mainly used for the filtration and separation of liquid and gaseous mixtures, and can replace traditional separation technologies such as centrifugation, evaporation, distillation and filtration to achieve the goal of improving product quality and reducing production costs It has a wide range of applications in harsh environments such as the petroleum and chemical industries.