Process for the regeneration of spent sulfuric acid

A process for the regeneration and concentration of spent sulfuric acid containing a substantial amount oxidizable organic impurities, which recovers over 90 percent of the sulfuric acid content of the feed as sulfuric acid while minimizing decomposition of sulfur trioxide to sulfur dioxide comprising:

• (a) providing at least one reactor vessel containing hot turbulent combustion products,
• (b) providing a regulated supply of oxygen to the reactor vessel,
• (c) atomizing spent sulfuric acid into the reactor vessel in droplets having mean droplet diameters less than 50 microns,
• (d) maintaining the temperature in the reactor vessel within the range 500.degree. to less than 800.degree. C.
• (e) withdrawing reaction products containing more than 0% and up to 10% free oxygen from the vessel at a rate such that the residence time of the spent acid mixture in the reactor is limited to that required to substantially complete the oxidation of the organic components,
• (f) removing the resulting mixture from the reactor vessel to a separate vessel and there cooling the mixture to condense water vapor and absorb sulfur trioxide in the condensed water, and
• (g) removing water from the condensate to produce the desired acid concentration.