Study on the Key Factors of NO Oxidation Using O₃: The Oxidation Product Composition and Oxidation Selectivity

Abstract

NO oxidation using O3 is studied, including the product composition under different conditions and the oxidation selectivity in complex flue gas. The O3/NO molar ratio determines the type of oxidation products. N2O5 is generated when the O3/NO molar ratio is greater than 1, and the N2O5 yield increases with the improvement of the O3/NO molar ratio. High temperature leads to the decomposition of NO3 and the decrease of the N2O5 yield. When NO3 decomposition is caused in the high-temperature region, the increase of the residence time is not beneficial to the generation of N2O5. In addition, water vapor in the flue gas is beneficial to the formation of N2O5 at low temperatures (60–90 °C), but SO2, CO, and HCl in the flue gas show little influence on the NO oxidation selectivity.

NOx Removal from Flue Gas Using an Ozone Advanced Oxidation Process with Injection of Low Concentration of Ethanol: Performance and Mechanism

“…When the flue gas temperature was 150 °C, the O 3 decomposition rate increased from 17.4 to 21.3% with the increase of the initial O 3 concentration from 100 to 400 ppm. The result implied that ozone was very unstable at high temperatures, which agreed well with the previous study . It was obvious that, when ozone was injected in hot flue gas at a temperature higher than 150 °C, a large part of the ozone oxidant would be lost without making contributions to oxidize NO x .…”

“…The result implied that ozone was very unstable at high temperatures, which agreed well with the previous study. 19 It was obvious that, when ozone was injected in hot flue gas at a temperature higher than 150 °C, a large part of the ozone oxidant would be lost without making contributions to oxidize NO x . 23 Therefore, it was necessary to control exhaust gas temperature below 150 °C in order to obtain a high utilization of the ozone oxidant.…”

“…In recent years, a low-temperature denitrification method combining ozone (O 3 ) oxidation and wet scrubbing in series has been proposed to remove NO x from flue gas. − For ozone oxidation, when the O 3 /NO ratio is about 1, NO in flue gas will be mainly oxidized into NO 2 through eq . − …”

Simultaneous Removal of NOx and SO2 by MgO Combined with O3 Oxidation: The Influencing Factors and O3 Consumption Distributions

“…For the oxidation temperature, a similar phenomenon was observed in our previous research. 38 The results showed that the N 2 O 5 yield first increased and then decreased with the increase of oxidation temperature, reaching the highest value at 90 °C for all O 3 /NO > 1. When the temperature of gas was higher than 90 °C, the N 2 O 5 yield decreased very rapidly.…”

Applicability of V2O5-WO3/TiO2 Catalysts for the SCR Denitrification of Alumina Calcining Flue Gas

“…Nitrogen oxide (NO x ), one of the main precursors of photochemical smog and haze pollution, causes great harm to the ecosystem and human lives [1,2]. Many strategies have been developed for NO x abatements from the stationary emission sources, including selective catalytic reduction (SCR) [3,4], selective non-catalytic reduction (SNCR) [5,6], activated carbon denitration [7,8], and oxidation-absorption method [9,10]. Among those methods, SCR technology has attracted extensive attention for being the most efficient strategy for NO removal [11].…”