SulfArc process

Air-diluted sulfides (up to 1% H₂S or 0.1% CH₃SH) were processed in gliding electrical discharges at up to 70 m³(n)/h pilot scale. Experiments were performed in one or four-stages GlidArc-I reactors at 1 atm. Each stage contains 3 main electrodes and one ignition electrode. These discharges produce non-thermal (cold) plasma, which activates oxidation reactions. Up to 100% clean-up was obtained at very low energy expense: 1 kWh of injected energy can remove all sulfides from 20 m³(n) of polluted air independently on initial pollutants' concentration in the range from 1 ppm to 1%. The process uses a very simple water-washing column, which saturates with the produced SO₂ and captures unprocessed H₂S via a wet Claus-like process so that we avoid any SO₂ emission and obtain non-toxic elemental Sulfur as the unique product:

3 H₂S + 1.5 O₂ = 2 H₂S + SO₂ + H₂O = 3S + 3 H₂O.

Schematic view

of the GlidArc I reactor

Schematic view

of the washing tower

Schematic view

of the four-stage reactor

SulfArc technologies can be useful for processing both diluted or concentrated sulfides' streams. Some more details on both applications can be found in the contribution to 16-th Int. Symp. on Plasma Chemistry, Taormina, Italy, June 2003.

___________________________________________________________________________________