[sloweather]

New member, mods please move if I picked the incorrect area.

For 10 years IU was a Wastewater Treatment Plant operator. We disinfected the the effluent with gaseous chlorine (Cl2) dissolved in water and injected into the effluent stream.  Then, prior to discharge into the receiving water, we were required to dechlorinate the effluent with gaseous sulfur dioxide (SO2) similarly dissolved in water and injected into the effluent stream.

The gasses were in 1 ton cylinders, with very similar rotametric feeders and injectors. However, for safety, the cylinder valves were threaded opposite (left vs right) so we couldn't mess them up. We were always cautioned that mixing the 2 gases would be catastrophic.

However, inquiring minds want to know...

Assuming we could connect Cl2 and SO2 gasses to a similar setup as say, an oxyacetylene torch, and negating any deleterious effects of the gases to the hoses, and to the metals of the regulators etc, what would happen if Cl2 gas and SO2 gas were mixed at the "best" ratio in open air? 

Thanks!

[Arkcon]

The reaction you've described is applied industrially:  http://pubs.acs.org/doi/abs/10.1021/i160061a009?journalCode=iecfa7  Usually this is done in water, or in the case of the above reference, on absorption media.  It produces HCl and H₂SO₄, and energetically.  I'd expect the gas phase reaction to produce at least some mist of strong acids, but I do I wonder if contact time is really enough for much to be made.  Sounds nasty, hot HCl gas and mist of sulfuric acid.

[phth]

^absorption media.  Carbon@300°C+1:1 mix will produce SO₂Cl₂ first, then SOCl₂ at longer reaction time (longer reaction path) and impurities are CCl₄, CO₂ and CO.  Metals are  added to quench the formation of impurities.