The heat generated by this reaction
vaporises approximately 30% of the water which
rises to the head of the column with any other
non-soluble components of the gas stream.
Pure hydrogen chloride streams containing only
air, water vapour and/or non-condensibles, are
condensed within the column and are returned together
with the make up water to the packed section.
A typical arrangement is shown in Figure 2.
If the hydrogen chloride is contaminated with
condensibles (other than water), i.e. the by-product
of a chlorination process, an arrangement as shown
in Figure 3
must be used. In this case the steam generated
together with any impurities rises to the head
of the column and is condensed in an external
heat exchanger. In some cases it is then possible
to separate aqueous and organic phases and return
the water to the column.
Whilst approximately 80% of the heat of solution
is removed by the condensers at the head of the
column, the remainder is removed at the base before
the product is run off. The heat exchanger supplied
with the unit guarantees an acid outlet temperature
of approximately 30 °C to 40 °C
The maximum possible gas loading and therefore
the quantity of acid produced is the same for
both types of absorber, and depends basically
upon the type of packing material in the column.
Performance data for Corning Process Systems
hydrogen chloride absorbers can be obtained from