Principle of membrane filtration
In membrane filtration, pressure is the driving force that promotes the physical separation. Membrane is defined as a thin physical structure that presents pores. Similar to the working principle of a sieve, the particles or molecules are retained by or pass through the pores of the membrane depending on their sizes.
This principle allows the separation and/or the concentration of suspended particles (inorganic particles, microorganisms) and molecules in a liquid.
The membranes can be used in the fractionation, purification, concentration, clarification or extraction of materials present in a liquid.
Multiple types of membranes exist, each type with specifications that suit better particular separation processes. This variety allows the membrane filtration technology to meet the widely different requirements of the Food & Beverage, Biopharma and Industrial & Environment industries.
The choice between organic and inorganic (ceramic) membranes depends on multiple variables such as permeability, selectivity, mechanical, thermal and chemical resistances, cost and lifetime.
Organic membrane filtration
Organic membranes are made of polymers such as cellulose acetate, polyamides, polyether sulfone, PVDF, etc.
The main advantages of organic membranes are the easiness of installation, wide variety of dimensions and the low cost. However, they are not suitable for extreme conditions.
All the advantages of organic membranes are summarized in the following table:
Organic membranes :
Criteria | Advantages | Disadvantages |
---|---|---|
pH | 🙂 | |
Temp. max | 🙂 | |
Congestion | 🙂🙂🙂 | |
Viscosity | *FC: 😖 *S: 😖 *P: 😖 *T: 😖 | |
Extension | FC: 🙂 S: 🙂 P: 🙂 T: 🙂 | |
Steam sterilizable | 😟😟😟 | |
Solvent resistance | 😟😟😟 | |
Lifetime | 😖 | |
Investment | 🙂🙂🙂 | |
Energy | FC: 🙂 S: 🙂 P: 🙂 T: 🙂 | |
Storage & membranes conservation | 😟😟😟 | |
Pretreatment | 😟😟😟 | |
Unit Malfunction | 😟😟 | |
Human error | 😟😟 | |
Control bacterial | 😟😟 | |
Bursting resistance | 😟 | |
Criteria | Advantages | Disadvantages |
F: Flat, T: Tubular.
For further informations : Contact us
Inorganic membrane filtration
Inorganic membranes are made of inorganic materials, such as carbon, sintered metals, metal oxides such as aluminum, titanium, zirconium, etc.
Similar to organic membranes, inorganic membranes are also used in the separation of substances and/or particles, however they are better suited to extreme conditions, such as extreme temperatures and harsh chemicals. Compared to organic membranes, inorganic membranes present superior resistance and durability, therefore requiring a higher investment.
All the advantages of inorganic membranes are summarized in the following table:
Inorganic Membranes (ceramic) :
Criteria | Advantages | Disadvantages |
---|---|---|
pH | 🙂🙂🙂 | |
Temp. max | 🙂🙂🙂🙂 | |
Congestion | 😖 | |
Viscosity | 🙂 | |
Extension | 🙂🙂🙂 | |
Steam sterilizable | 🙂🙂🙂 | |
Resistance Solvent | 🙂🙂🙂 | |
Lifetime | 🙂🙂🙂 | |
Investment | 😟 | |
Energy | 🙂 | |
Storage & membranes conservation | 🙂🙂🙂 | |
Pretreatment | 🙂🙂🙂 | |
Malfunction of the unit | 🙂🙂🙂 | |
Human error | 🙂🙂🙂 | |
Control bacterial | 🙂🙂🙂 | |
Bursting resistance | 🙂🙂🙂 | |
Criteria | Advantages | Disadvantages |
Different membrane filtration processes
SIVA is specialized in four ranges of membrane filtration that rely on pressure as the driving force: microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Each filtration range is defined by the size of the molecules and particles passing through the membrane.