Optimization of sulfite oxidation kinetics in seawater desulfurization technology for fossil power plants due to efficient aeration

Copyright: © Doosan Lentjes Oxidation pool and absorber of the Gheco One plant, Thailand

The purpose of the research project Optiox is the optimization of an aeration basin as a central component of a seawater based desulfurization facility for fossil fired power plants. Sulfur dioxide is absorbed by means of scrubbing technology and transformed to sulfites. The whole process is possible due to the natural alkalinity of the seawater (dissolved carbonates). In the aeration basin, the sulfites are oxidized using injected pressurized air, which results in a slightly increased sulfate load of the exhaust flow into the sea. In addition, the aeration basin is used for adjusting pH and oxygen saturation of the effluent, which is why the basin is equipped with high efficient aeration elements. Both number and formation of these elements have to be defined with respect to local requirements, including precipitation efficiency of the scrubber, constructive aspects of the basin and environmental parameters.

Central goal of this project is a scientific comparison of different aeration technologies with special respect to the application under operation conditions of the seawater desulfurization. A characterization and assessment is done with regard to the gas-fluid mass transfer from fine bubbles to the effluent water. Evaluations are done with attention to the different requirements of aeration (O₂) and CO₂-stripping and focused on specific parameters of the evoked bubbly flows including ascension, gas contents and determination of multi-phase boundary surfaces. Furthermore, an optimization of process technology with regard to all actuating variables on mass transfer and reaction process (chemical equilibrium parameters, reaction kinetics and mass transfer coefficients) will be done.