The present invention relates to a process for preparing largely HBr-free HCl
gas and largely HBr-free aqueous HCl solution, which comprises the following steps:
a) providing HBr-containing HCl gas;
b) passing the HBr-containing HCl gas through aqueous HCl solution saturated
with HCl;
c) separating off HBr-containing aqueous HCl solution saturated with HCl;
d) if desired, passing the largely HBr-free HCl gas obtained in step b)
into water to obtain largely HBr-free aqueous HCl solution;
with largely HBr-free aqueous HCl solution produced in step d) being able, if
desired, to be recirculated to step b) of the process.
The process of the present invention allows high-purity aqueous HCl solution
for use in the semiconductor industry to be prepared inexpensively and on an industrial
scale. However, the purified HCl gas obtained by means of steps a) to c) can also
be used for any other purposes. The invention likewise provides an apparatus for
carrying out the process of the present invention.
