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Environment & Society    The artificial production of pure
chlorine gas is accomplished by the electrolysis of salt water,
or sodium chloride (NaCl) brine. Because the oceans provide a
practically inexhaustible supply of salt water, the supply of
chlorine is thought to be  inexhaustible as well.  There are two
processes used in the commercial production of chlorine. In one,
the cathode in the electrolysis cell consists of a flowing bed
of mercury. The sodium released in the electrolysis of NaCl
amalgamates with the mercury. The mercury-sodium amalgam is then
dissociated in a separate cell to form sodium hydroxide (NaOH)
and the mercury returns to the main cell to be reused. At the
anode chlorine gas is released, cooled with water, dried with
sulfuric acid, then collected and compressed. Due to the health
concerns regarding mercury, this method is being phased out.
The second method is called the diaphragm cell process. In this
process, rather than removi