(42a) WSA (Wet gas Sulfur Acid) Technology - A Competitive Solution for Sulfur Management

For more than 30 years Haldor Topsoe has designed plants for purification of sulfur containing waste gases derived from a wide variety of process industries. The WSA (Wet gas Sulfuric Acid) technology is efficient for recovering H₂S or other sulfur compounds in the form of commercial grade sulfuric acid. Moreover, the exothermic reaction energy generated when converting the sulfurous off-gas is efficiently recovered in the process as valuable superheated high pressure steam available for export.

The WSA technology is also characterized by high sulfur removal efficiency with more than 99% sulfur recovery, up to 99.99% when required, and is always in compliance with emission legislation. The process does not consume any chemicals nor will there be any solid or liquid effluents requiring additional treatment. This in combination with very low cooling water consumption makes WSA technology a very competitive solution for treatment of acid gases.

The WSA technology has proven feasible for treating sulfurous gases in many different applications, and today more than 140 units have been contracted worldwide handling a wide range of gas flows and with daily sulfuric acid production ranging from 4 to 1,140 MTPD.

The paper will explain the basic principles of the WSA technology and will include economical figures and the comparison with the typical alternatives for sulfur removal.