Disposal of Waste Gases
Marcus Sittenfield
Consulting Chemical Engineer
Philadelphia, Pennsylvania
The problem of the disposal of waste gaseous materials has become
a matter for very serious consideration in recent years as a result of
two main factors. The first is that of process economics, and the
second is a result of public and legal pressure to abate a nuisance.
Under the first heading, it can readily be seen that the disposal
of the gases formed as by-products in manufacturing processes by vent¬
ing them into the atmosphere is very far from being economical.
Present-day competition makes it imperative to provide means for the
recovery of these gaseous substances and their conversion into profitable
materials.
In connection with the second factor, it must be recognized that
many of the vented gaseous substances may be corrosive, poisonous,
or just a nuisance. The clamor of neighbors for the alleviation of
such conditions must be heeded.
Gaseous products range in size from molecular gases to dust par¬
ticles of over 200 microns. From a broad point of view, these aerosols
may be classified as "neutral" or "active". This classification is par¬
ticularly of interest when discussing the effects of these substances on
community air pollution.
Neutral dusts are those materials which result from the weathering
of rocks, drilling, quarrying, coal mining, and similar operations. They
are non-hygroscopic in nature and range in size from about one micron
to over 100 microns.
Active dusts are those resulting from combustion, chemical, or
metallurgical processes. They are usually below 50 microns in size
and have a tendency to act as condensation nuclei for any water vapor
that is present in the atmosphere.
From the point of view of this paper, however, the classification
of "neutral" and "active" particles has little application. More interest
is expressed in a classification based on the methods used for the dis¬
posal of these aerosols, i.e., the dusts, fumes, and gases that are vented
as waste products from industrial operations.
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