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Optimisation of WSA technology


Topsoe's WSA process - Wet gas Sulfuric Acid - is used for cleaning sulfurous off gases. The content of sulfur dioxide (SO2) in the flue gas is catalytically oxidized into sulfur trioxide (SO3) and by reaction with water converted to sulfuric acid (H2SO4) - commercial quality concentrated sulfuric acid.

Project goal

The project investigates two areas for possible improvement of the process:

Combustion of sulfur feed stocks catalytic oxidation, hydration and condensation are all exothermal reactions. The excess heat is used for steam production and process-to-process heat recovery. The integration of energy and the degree of heat recovery in a WSA plant was investigated in order to identify possibilities for improvement.

The parameters for allowable emissions differ from Chinese environmental legislation to European legislation. As the market in China is growing, it is desirable to adapt the design of the WSA units by optimizing the operating conditions to meet the Chinese environmental legislation demands in the most economical way using the advantages of the WSA process.

In order to determine an economical optimum for design of the process it was investigated how different operating conditions influence on the design of equipment and production figures.


Annette Wendt, LTH, Department of Chemical Engineering
Master thesis in the Technology Division, Environmental Process Engineering Department