Filtration and Ultrafiltration
Introduction
Filtration
and ultrafiltration are two of the most important separation techniques used
both in laboratory research and industry to separate solid particles from
liquids and gases. Both filtration and
ultrafiltration play a vital role in improving process efficiency and plant
safety while reducing a plant’s costs and environmental impacts. Employing 
these
separation techniques can keep both gases and liquids clean, extend the life of
plant components, and improve product quality.
The
more tradition forms of filtration
including rotary vacuum filtration (RVF) and centrifugation, which have
historically been used for many of the solid-liquid separation process steps
required in pharmaceutical and food processing. Recently, these industries have been
evaluating and utilizing membrane Membrane Device
[4]
based technologies used in applications where RVFs and centrifuges were
employed. Membrane systems offer many
advantages over the traditional systems and therefore are becoming widely used
in both the laboratory and in industry to purify and concentrate macro and
micromolecular products. Membranes are attractive for use in separation due to
their permselective properties, their large internal adsorptive surface area,
and their useful mass transfer characteristics. They can be used in fermentors and bioreactors to transport gases
into the vessel and transfer cell culture medium out of the vessel. Without the need for vaporization, membrane
separations can also operate with much less energy consumption.
The
pharmaceutical and biotechnology industries are quickly adopting membranes as
their filtration device of choice. The
gentle separation process is perfect for proteins or other thermally unstable
compounds that would be destroyed in a distillation column. A well-designed membrane separation wastes
less product than almost any other form of separation out there today. Although it is a slower and lower volume
process than most other separation processes out there today, its effectiveness
makes it ideal for retrieving small amounts of very expensive products.
So what is a membrane? They are not an invention of man. They are an invention of nature. They can be found everywhere in nature. The lungs we breathe with represent an
incredibly complex yet effective membrane system. Actually every living cell in the world represents a small
membrane system.
Membranes have found a home in many areas
beyond the pharmaceutical and biotechnology arenas as well. Although membranes are excellent for
expensive high profile separations, they can also be ideal for low cost “simple”
systems as well. Some areas membranes
can be found today are the separation of gases, removal or microorganisms from
air or water streams, water purification, ethanol production in a continuous
fermentation/membrane pervaporation system, detection of trace elements in air
or water streams, and a whole host of exotic applications that require either
the high selectibility of an advanced membrane system, or the simplicity and
low cost of a filter system.
To learn more about membranes and other filtration devices and techniques, take a look at the links below…..
Related Topics:
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Membrane Filtration Vs. Traditional Methods Biological Filtration: The Kidney |
Created by: Danielle Beurer and Courtney Wells
Biochemical Engineering Project-Fall 2000