A Hybrid-Sulfur Flowsheet Using an Ionic Liquid Absorbent to Separate Sulfur Dioxide from Oxygen

A hybrid sulfur (HyS) flowsheet using an ionic liquid absorbent to separate SO2 from oxygen has been developed. The key chemical reactors in the HyS flowsheet are a sulfuric acid distillation column, a sulfuric acid vaporization and decomposition reactor, a knock-out drum to separate SO2/O2-mixed gas from the SO3/H2O-recombined and condensed aqueous phase, a separation part of SO2, and a SO2-depolarized electrolysis cell. The separation part of SO2 consists of SO2 absorption and desorption columns adopting a temperature swing methodology. The hydrogen production thermal efficiency of 39% can be expected by this HyS process.