Studies on regeneration mechanism of sulfur transfer additives of FCC flue gas by H2 reduction

Transient response technique in combination with online quadruple mass spectrometry was used to study the reduction mechanism of different gaseous reducing agents on sulfate compounds formed on a sulfur transfer catalyst at atmospheric pressure and different temperatures. The results indicated that the SO2 and H2S released almost at the same time and after several cycles of pulse reaction, the formation of SO2 ceased and only H2S was detected as reduction product.

► The SO2 and H2S released almost at the same time.
► The formation of SO2 ceased and only H2S was detected after several pulse numbers.
► The mechanism generally involves the following reactions: {MSO4+H2=MO+SO2+H2OMSO4+4H2=MO+H2S+3H2O.