(127f) Modeling and Sensitivity Analysis of the Aqueous Oxidation Reactions of Nitric Oxide Induced By Thermal Activation of Peroxydisulfate

Pollutants emitted from combustion sources are of great public concern due to their detrimental effects on human health and ecosystems. Although multi-pollutants’ reductions from flue gas using different processes such as selective catalytic reduction, lime/limestone wet flue gas desulfurization and activated carbon, respectively for NO_x, SO₂ and Hg removal, are efficient purification techniques, these complex treatment processes require high construction and operational costs, and large installation space. It is desirable to develop cost-effective especially those capable of providing simultaneous multi-pollutants’ control. It is desirable to develop a new single integrated and cost-effective technology, which could also possibly be retrofitted to existing power plant. Advanced oxidation technologies (AOTs) are defined as those technologies that can generate mainly the hydroxyl radical (·OH) with high oxidation potential and other reactive oxygen species including superoxide anion radical (O₂^.-), hydrogen peroxide (H₂O₂) and singlet oxygen, by various environmentally benign physical or chemical processes. Such technologies, which could also possibly be retrofitted to existing power plant are believed to be more cost-effective. Sulfate-radical () based advanced oxidation processes (AOPs) have drawn increasing attention in research and successful applications in water treatment and soil remediation as well as in flue gas purification for multipollutant treatments. The persulfate (PS) or peroxydisulfate anion (S₂O₈^2-) is a strong oxidant, kinetically slow at ordinary conditions but activation by heat, ultraviolet (UV), ultrasound, microwave, transition metal ions, electrodes, nanoparticles or base (and alkaline pH) resulting in the generation of sulfate (, and subsequent production of hydroxyl (OH^•) radicals. Despite the recent numerous studies of NO removal by activated persulfate, the mechanisms are still not well understood. This work involves experimental studies and the development of a kinetic-mass transfer utilizing a comprehensive reaction scheme for process evaluation of the aqueous removal of nitric oxide (NO) in a simulated flue gas by heat-activated persulfate in a bubble-column reactor. For the first time, a sensitivity analysis and rate of production analysis are used to investigate the contributions of each homogeneous reaction to NO oxidation in the detailed mechanism to reveal the dominant pathway(s), and evaluate the effects on the predicted concentrations of key products. This talk will comprehensively evaluate the chemistry/kinetics, oxidant utilization (which impacts treatment cost), scale-up issues, and economic viability of these techniques for flue gas cleanup; and outline directions for the developments of innovative technologies for large-scale applications.