Sulfur dioxide recovery from gases employing organic bases

Claim 1

A PROCESS FOR THE RECOVERY OF SULFUR DIOXIDE FROM GASES CONTAINING THE SAME, COMPRISING THE STEPS OF CONTACTING AN ORGANIC BASE SELECTED FROM THE GROUP CONSISTING OF XYLIDINE, TOLUIDINE, QUINOLINE, DIMETHYLANILINE, HEAVY PYRIDIC BASES FROM COAL TAR, METHYLAMINE AND ETHANOLAMINE WITH A GAS CONTAINING SULFUR DIOXIDE SO AS TO CAUSE ABSORPTION OF AT LEAST THE MAJOR PORTION OF SAID SULFUR DIOXIDE BY SAID BASE; TREATING SAID SULFUR DIOXIDE CONTAINING BASE WITH AN OXYGEN-CONTAINING GAS WHICH IS SUBSTANTIALLY FREE OF SULFUR DIOXIDE SO AS TO OXIDIZE A PORTION OF SAID ABSORBED SULFUR DIOXIDE TO SULFUR TRIOXIDE AND TO INCREASE THE CAPACITY OF SAID BASE FOR ABSORBING ADDITIONAL SULFUR DIOXIDE; CONTACTING THE THUS-TREATED BASE WITH ADDITIONAL SULFUR DIOXIDE-CONTAINING GAS SO AS TO CAUSE ABSORPTION OF AT LEAST THE MAJOR PORTION OF THE THUS ADDITIONALLY INTRODUCED SULFUR DIOXIDE; AND RECOVERING ABSORBED SULFUR DIOXIDE FROM SAID BASE.