Removal of Bromine From Gaseous Hydrogen Bromide

A process of removing bromine from a gaseous mixture comprising hydrogen bromide and bromine, which process comprises:

• passing said gaseous mixture into contact with a primary scrubber composition that removes a substantial amount of the bromine from said gaseous mixture, and passing the resultant partially debrominated gaseous mixture into contact with a secondary scrubber composition that removes additional bromine from the gaseous HBr;
• A) wherein said primary scrubber composition comprises:
• (1) a mixture comprising alkylated aromatics including, but not limited to, 1,2-diphenylethane and oligomers thereof, said mixture containing and amount of 1,2-diphenylethane of up to about 30 wt %, or
• (2) a brominatable partially brominated substrate composition of (1), or
• (3) a mixture of (1) and (2);
• and
• wherein said primary scrubber composition is free of any added bromination catalyst;
• B) wherein said secondary scrubber composition comprises
• (4) an aluminum chloride and/or aluminum bromide bromination catalyst,
• (5) one or more activated aromatic compounds that
• (i) are thermally stable at 70° C. under nitrogen, and
• (ii) are chemically and thermally stable in the presence of HBr at least up to 120° C.;
• (6) a partially brominated derivative of any one or more of the components of (5);
• and
• C) wherein said primary and secondary scrubber compositions are kept at temperature(s) that during the scrubbing operation maintain these respective scrubber compositions in flowable liquid states.