After Danish company Haldor Topsoe introduced this technology in 1987, it has been recognized as a process for recovering sulfur from various process gases in the form of commercial quality sulfuric acid (H2SO4) with the simultaneous production of high-pressure steam.
These gases were previously vented to the atmosphere, but now the acid gas requires purification in order not to affect the environment with SO2 emission.
The WSA process provides a high sulfur recovery and recovers heat for steam production.
The heat recovery rate is high, and the cooling water consumption is low, which saves resources.
The concentration of the product acid depends on the H2O:SO3 ratio in the catalytically converted gases and on the condensation temperature.