ORP as slurry oxidation index and model modification in wet desulfurization system.

Unlabelled: Due to wet desulfurization system lacks effective control indicators for the oxidation process, so the sulfite oxidation in the slurry and the quality of gypsum become unstable. In this paper actual desulfurization system operation data are used to improve the ORP semi-empirical formula obtained in the laboratory. It was concluded that the ORP was mainly affected by the concentration of sulfite and pH during the operation of the actual desulfurization system, the dissolved oxygen was less affected by the small concentration change during operation. It is verified that the model can correct the ORP measurement value by using other conventional measurement data from the power plant. The results can provide theoretical support for adding ORP as a control index to optimize the oxidation process.

Implications: At present, the main control parameter of wet FGD is pH control, but wet FGD has two main reactions at the same time, one is acid-base reaction, the other is redox, single pH control can not reflect the degree of redox, so it is necessary to introduce another control index to evaluate redox, which is the ORP control proposed in this paper, ORP can reflect the degree of slurry oxidation, avoid the occurrence of excessive oxidation and inadequate oxidation, so that the operation of desulfurization system can be more healthy and stable.