Dielectric barrier discharge coupling catalytic oxidation for efficient conversion of Hg0 from flue gas

Unique Cluster-Support Effect of a Co3O4/TiO2-3DHS Nanoreactor for Efficient Plasma-Catalytic Oxidation Performance

“…It is known that H 2 O is usually used as a source to generate OH* in the NTP process via eq . , From Figure d, it can be seen that the incorporation of water vapor significantly reduces the catalytic activity of Co 3 O 4 /TiO 2 under low V P–P (21–25 kV) conditions, which is consistent with our previous study. , One of the reasons is that H 2 O will capture a large number of electrons, resulting in the reduction of high-energy electrons. Another reason is that H 2 O will compete with NO for active sites on the catalyst surface. ,, When V P–P increases from 25 to 29 kV, the discharge energy increases gradually. The more the discharge energy increases, the more free radicals (O*, OH*) are produced. , Therefore, the oxidation efficiency of NO gradually increases with the increase of V P–P and reaches the highest value (91.5%) at 29 kV.…”

“…Compared with the Co 3 O 4/ TiO 2 catalyst, Co 3 O 4 /TiO 2 -3DHS has lower conversion efficiency for SO 2 (∼30%), based on which it is speculated that the reaction rates corresponding to eqs and are much lower than those on the surface of Co 3 O 4 /TiO 2 . Given SO 3 is a strong acidic gas and a major source of the corrosion of the pipe wall, it is reasonably expected that Co 3 O 4 /TiO 2 -3DHS can remarkably improve the anti-corrosion of NTP reactors, as confirmed by a 1-h continuous test, as shown in Figure S6 (Supporting Information). Given that both present the same Co 3 O 4 catalysts, we can speculate that the excellent sulfur resistance of Co 3 O 4 /TiO 2 -3DHS is mainly attributed to its unique three-dimensional hollow structure.…”

“…In addition, the conversion efficiency of SO 2 is lower than that of NO in the given V P–P range, which is directly related to the fact that the reaction rate constants of NO with O* and O 3 are much higher than those of SO 2 with O* and O 3 . , SO 2 + normalO * → SO 3 SO 2 + normalO 3 → SO 3 + normalO 2 Figure d evaluates the catalytic oxidation efficiency of NO under the coexistence of SO 2 and H 2 O. It is known that H 2 O is usually used as a source to generate OH* in the NTP process via eq . , From Figure d, it can be seen that the incorporation of water vapor significantly reduces the catalytic activity of Co 3 O 4 /TiO 2 under low V P–P (21–25 kV) conditions, which is consistent with our previous study. , One of the reasons is that H 2 O will capture a large number of electrons, resulting in the reduction of high-energy electrons. Another reason is that H 2 O will compete with NO for active sites on the catalyst surface. ,, When V P–P increases from 25 to 29 kV, the discharge energy increases gradually.…”

“…The main components of the experimental NO oxidation platform are a gas distribution system, a DBD reactor, and a gas analysis system (Figure S2, Supporting Information) . In brief, a quartz tube with an inner diameter of 20 mm and an outer diameter of 25 mm served as a dielectric layer.…”

Experimental and Kinetic Analysis of H2O on Hg0 Removal by Sorbent Traps in Oxy-combustion Atmosphere

“…The OH radical can oxidize Hg 0 to HgO, which promotes the removal of mercury. Reactions and are the related reaction equations. , The presence of oxygen may form the OH group through reactions and and react with Hg 0 . − Thus, a low concentration of H 2 O can promote the adsorption of mercury. However, the existence of 20% H 2 O will compete with mercury for the adsorption and oxidation active sites, leading to a decrease of the mercury adsorption capacity. , The enriched H 2 O inhibits the oxidation ability of Hg 0 through supplying additional electrons (e – ) on the surface of sorbent traps, and the additional electrons can eliminate Hg 2+ and form Hg 0 by reaction . , The existence of mercury compounds on the spent adsorbent surface can be obtained by the TPD experiment. As shown in Figure , HgO is the dominating speciation on the spent adsorbent surface. …”