Simultaneous Removal of NOx and SO2 through a Simple Process Using a Composite Absorbent

Abstract

In this work, the feasibility of the simultaneous removal of NOx and SO2 through a simple process using a composite absorbent (NaClO2/Na2S2O8) was evaluated. Factors affecting the removal of NOx and SO2, such as NaClO2 and Na2S2O8 concentrations, solution temperature, the initial pH of solution, gas flow rate, and SO2, NO, and O2 concentrations were studied, with a special attention to NOx removal. Results indicate that a synergistic effect on NOx removal has been obtained through combination of NaClO2 and Na2S2O8. NaClO2 in the solution played a more important role than did Na2S2O8 for the removal of NOx. The above factors had an important impact on the removal of NOx, especially the solution temperature, the initial pH of the solution, and the oxidant concentrations. The optimum experimental conditions were established, and a highest efficiency of NOx removal of more than 80% was obtained. Meanwhile, tandem double column absorption experiments were conducted, and a NOx removal efficiency of more than 90% was reached, using NaOH solution as an absorbant in the second reactor. A preliminary reaction mechanism for NOx and SO2 removal was deduced, based on experimental results. The composite absorbent has the potential to be used in the wet desulfurization and denitration process, to realize the synergistic removal of multi-pollutants.

Jet electro-absorbers for the treatment of gaseous perchloroethylene wastes

“…As well, sodium hydroxide and sodium hypochlorite were found to be good active components to promote the absorption process [4]. More recently, it was also evaluated the simultaneous removal of other gaseous pollutants such as NOx, SO2 and CO2 with a composite absorbent (NaClO2/Na2S2O8) obtaining among 80% and 90% of efficiency [5]. These progressive advances in the treatment of those pollutants have promoted the application of absorbers, using strong oxidative streams as absorbents, in the treatment of gaseous emissions from wastewater treatment plants (WWTP), where various organosulfur compounds mixed with trace quantities of volatile organic compounds (VOC) are contained [6].…”

New Insight into the Characteristics and Mechanism of Hg0 Removal by NaClO2 in Limestone Slurry

“…This is mainly because the Hg 0 concentration in flue gas is relatively low and SO 2 preferentially reacts with NaClO 2 in the limestone slurry, resulting in a significant reduction of the efficient Hg 0 removal duration by NaClO 2 . The specific reaction process of SO 2 and NaClO 2 in limestone slurry is shown in eqs –. ,, For the limestone slurry without NaClO 2 , the desulfurization process mainly follows the reaction of eqs –. However, when NaClO 2 is added to the limestone slurry, the desulfurization process will follow the reaction of eqs and in addition to the above process.…”

Sustainability Outcomes of Green Processes in Relation to Industry 4.0 in Manufacturing: Systematic Review

“…Radiation [233], solid waste [234], low carbon and mitigating CO 2 technologies [235], disaster prevention [236], purification [237], protection, remediation [238], greenhouse gas (GHG) reduction [239], dust removal [240], desulfurization and denitration [241], heavy metal pollution prevention [208], rural pollution control technology [242].…”