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Activated carbon is an amorphous form of elemental carbon prepared by destructive
distillation of any one of a variety of carbonaceous raw materials, including
wood, coal or coconut shells. It is used as a substrate primarily to selectively
adsorb gases, vapors or colloidal solids from liquids or gases. The principal
commercial product forms of activated carbon are granular, powdered, extruded
and fibers.
The following pie chart shows world consumption of activated carbon in 2005:
The major impact of environmental concerns on activated carbon markets is
a very positive one. Such concerns and the regulatory activities they engender
are the largest single driving force behind the substantial growth that activated
carbon has enjoyed in the past two decades. This driving force appears likely
to continue to push the growth of activated carbon in the future, particularly
in the developing industrial areas of the world where water and air pollution
are becoming serious problems.
In the major industrial areas, growth in activated carbon consumption for
environmental protection may be slightly slower than in the past few years
as a result of at least two factors. One is the strategy urged by the U.S.
Environmental Protection Agency to reduce pollution by not creating it in the
first place—that is, by changing industrial processes and equipment to
manufacture products without generating waste products that become pollutants.
This strategy is beginning to have a sizable impact on the volume of waste
products and pollution generated by industry.
The other factor limiting activated carbon consumption for environmental control
is the continued development of competitive technologies, such as ozonation,
biological and phytological remediation and many others. These new technologies
will, in some cases, substitute for or alleviate the need for the use of activated
carbon in pollution control applications.
Environmental concerns have had a negative impact on activated carbon companies
in a few cases in the United States and in Western Europe. The basic manufacturing
processes for activated carbon can be polluting in themselves if not properly
designed and operated. The emission of carbon dust particles (either airborne
or in wastewater streams) from activated carbon plants have been reported in
a few isolated incidents, for example.
A potentially more serious problem is the reintroduction of waste materials,
hazardous or otherwise, into the environment from activated carbon reactivation
plants that are not properly designed or operated to handle such materials.
The activated carbon processed in these plants is loaded with waste materials
when it enters the plant. In some cases, such wastes are safely decomposed
by the high temperatures used to reactivate the carbon. In other cases, such
as with halogenated organics, the decomposition products are themselves toxic
and must be controlled in one way or another. Inorganic waste materials (e.g.,
heavy metals or radioactive materials) are not generally decomposed by heat
and so must be disposed of safely after removal from the activated carbon substrate.
The activated carbon business will continue to be driven by environmental
regulations, principally water and air purification, especially in the mature
and more industrialized areas of the world in the future. Environmental issues
will likely become the predominant force in the markets of rapidly developing
countries as well in the next five years.
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