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1991 | Buch

Basic Principles of Membrane Technology

verfasst von: Marcel Mulder

Verlag: Springer Netherlands

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Über dieses Buch

Membranes playa central role in our daily life, or as indicated by one of my foreign colleagues, Richard Bowen, 'If you are tired of membranes, you are tired of life' . Biological membranes are hardly used in industrial applications, but separations with synthetic membranes have become increasingly important. Today, membrane processes are used in a wide range of applications and their numbers will certainly increase. Therefore, there is a need for well educated and qualified engineers, chemists, scientists and technicians who have been taught the basic principles of membrane technology. However, despite the growing importance of membrane processes, there are only a few universities that include membrane technology in their regular curricula. One of the reasons for this may be the lack of a comprehensive textbook. For me, this was one of the driving forces for writing a textbook on the basic principles of membrane technology which provides a broad view on the various aspects of membrane technology. I realise that membrane technology covers a broad field but nevertheless I have tried to describe the basic principles of the various disciplines. Although the book was written with the student in mind it can also serve as a first introduction for engineers, chemists, and technicians in all kind of industries who wish to learn the basics of membrane technology.

Inhaltsverzeichnis

Frontmatter
I. Introduction
Abstract
In 1861, at about the time that Graham reported his first dialysis experiments using synthetic membranes [1], Maxwell created the ‘sorting demon’, “a being whose faculties are so sharpened that he can follow every molecule in its course and would be able to what is at present impossible to us” [2]. In other words, the demon is able to discriminate between molecules. Suppose that a vessel is divided into two parts A and B by a division in which there is a small hole and that Maxwell’s demon sits at the hole which he can open and close at will (see figure I — 1).
Marcel Mulder
II. Materials and Material Properties
Abstract
Membranes can be made from a large number of different materials. As mentioned in chapter I, a first classification can be made into two groups, i.e. biological and synthetic membranes. Biological membranes are essential for life on earth. Every living cell is surrounded by a membrane, but these membranes differ completely in structure, functionality etc. from synthetic organic and inorganic membranes. A detailed description is beyond the scope of this book but a short survey will be given at the end of this chapter.
Marcel Mulder
III. Preparation of Synthetic Membranes
Abstract
In chapter II it was shown that a large number of materials can be used as the basis for membrane preparation. A number of preparation techniques exist which enable a membrane to be constructed from a given material. The kind of technique employed depends mainly on the material used and on the desired membrane structure (which in turn is dependent on the separation problem). Three basic types of membrane can be distinguished based on structure and separation principles:
  • porous membranes (microfiltration, ultrafiltration)
  • nonporous membranes (gas separation, pervaporation)
  • liquid membranes (carrier-mediated transport)
Marcel Mulder
IV. Characterisation of Membranes
Abstract
Membrane processes can cover a wide range of separation problems with a specific membrane (membrane structure) being required for every problem. Thus, membranes may differ significantly in their structure and consequently in their functionality. Many attempts have been made to relate membrane structure to transport phenomena, in an effort to provide a greater understanding of separation problems and possibly predict the kind of structure needed for a given separation.
Marcel Mulder
V. Transport in Membranes
Abstract
A membrane may be defined as a permselective barrier between two homogeneous phases. A molecule or a particle is transported across a membrane from one phase to another because a force acts on that molecule or particle. The extent of this force is determined by the gradient in potential, or approximately by the difference in potential, across the membrane (ΔX) divided by the membrane thickness (l), i.e.
Marcel Mulder
VI. Membrane Processes
Abstract
All membrane processes have the common feature that separation is achieved via a membrane. The membrane can be considered to be a permselective barrier existing between two homogeneous phases. Transport through the membrane takes place when a driving force is applied to the components in phase 1. In most the membrane processes the driving force is a pressure difference or a concentration (or activity) difference across the membrane. Parameters such as pressure, concentration (or activity) and even temperature may be included in one parameter, the chemical potential µ.
Marcel Mulder
VII. Polarisation Phenomena and Membrane Fouling
Abstract
In order to achieve a particular separation via a membrane process, the first step is to develop a suitable membrane. However, during an actual separation, the membrane performance (or better the system performance) can change very much with time, and often a typical flux-time behaviour may be observed: the flux through the membrane decreases over time. This behaviour is shown schematically in figure VII — 1 and is mainly due to concentration polarisation and fouling.
Marcel Mulder
VIII. Module and Process Design
Abstract
In order to apply membranes on a technical scale, large membrane areas are normally required. The smallest unit into which the membrane area is packed is called a module. The module is the central part of a membrane installation. The simplest design is one in which a single module is used. Figure VIII — 1 gives a schematic drawing of such a single module design.
Marcel Mulder
Backmatter
Metadaten
Titel
Basic Principles of Membrane Technology
verfasst von
Marcel Mulder
Copyright-Jahr
1991
Verlag
Springer Netherlands
Electronic ISBN
978-94-017-0835-7
Print ISBN
978-0-7923-0979-6
DOI
https://doi.org/10.1007/978-94-017-0835-7