Simultaneous absorption of NOx and SO2 from flue gas with pyrolusite slurry combined with gas-phase oxidation of NO using ozone

Background: One of the important achievements of the past decade was the rapid growth of industries and accordingly production of various chemical compounds.Objectives: This study presents a combined system of photocatalytic oxidation and absorption solution to remove nitrogen oxides from polluted air flow. Materials and Methods:The experimental system used in this study comprised a pollutant gas source, mixing chamber, photocatalytic oxidation reactor, wet absorption system, and finally a system for measuring nitrogen oxides. Firstly, by using photocatalytic property, nitrogen oxide was converted to nitrogen dioxide. Then, absorption system was used to absorb nitrogen dioxide into the sodium hydroxide solution. Results: Experimental results have shown that output of nitrogen oxide removal in the initial concentration of 200 ppm was 44% in the beginning of the process and then fixed at 15% during the rest of the process. Also, by changing the amount of zinc oxide nanoparticles from 4 to 8 mg/cm 2 , no considerable change was observed in the conversion rate of nitrogen oxide. In addition, while

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“…toxic gas in the case of saturation which is more dangerous than the initial nitrogen oxide product (19,32).…”

Section: Effect Of Initial Concentration and Sodium Hydroxide Solutiomentioning

confidence: 99%

Investigation of Photocatalytic Oxidation and Wet Absorption in a Combined System for Removal of Nitrogen Oxides

2016

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“…Our previous studies show that the high efficiencies of desulphurization and manganese extraction can be attained when low-grade manganese ore was used as absorbent to remove SO 2 in flue gas (Sun et al, 2011;Sun et al, 2013); however, it takes a long time to obtain more than 90% manganese, requiring more than 15 h, which is due to low content of SO 2 in flue gas (below 1% SO 2 ). In this work, simulated flue gas (high concentration of SO 2 contained) was taken to reduce the high-iron pyrolusite ore to simultaneously investigate the leaching behavior of manganese and iron and separation efficiency of manganese from iron.…”

Section: Introductionmentioning

confidence: 99%

Study on Separation of Manganese from Iron in High-Iron Pyrolusite Ore by Leaching with Simulated Flue Gas

Deng

et al. 2017

J. Chem. Eng. Japan / JCEJ

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Due to the depletion of high-grade manganese ore, much attention has turned to recover manganese from low-grade ores; however, these are usually associated with high-iron content. Moreover, the conventional process of extracting Mn from iron-rich low grade manganese oxide ore focused on recovery of Mn, while ignoring the leaching characteristics of Fe. Hence, simultaneous investigations on leaching behavior and separation e ciency of both manganese and iron were carried out for attaining high recovery of manganese with low iron content from the high-iron low-grade pyrolusite ore using simulated ue gas as the reductant. The e ects of leaching parameters, ue gas components and initial particle size on the leaching e ciency of Mn and Fe were studied, and the results indicated that higher separation e ciency of Mn from iron was achieved at lower SO 2 concentration, O 2 concentration and suitable pulp density. The experimental validation revealed that 93.12% Mn and only 2.57% Fe were extracted under the optimal operating conditions: SO 2 percentage of 5%, O 2 percentage of 1%, reaction temperature of 35°C, solid-to-liquid ratio of 250 g/L, and more than 120 min. Kinetic modelling has indicated that the Mn leaching rate is controlled by the rate of di usion of SO 2 /O 2 from the gas phase to the liquid phase, and the rate of di usion of product or reactants to the ore surface through an inert product layer is the rate-limiting step for Fe dissolution.

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“…It was established that increasing the contact time between ozone and exhaust gas, improves efficiency of NOx and Hg 0 removal (Dora et al, 2009). Interesting studies were performed by combining ozonation with addition of ethanol (Jie et al, 2016) and pyrolusite (Sun et al, 2011), and applying catalysts (cerium-titanium) (Jie et al, 2014). Results are promising, but the methods are still at the stage of laboratory tests.…”

Section: Introductionmentioning

confidence: 99%

Influence of Oxidizing Reactor on Flue Gas Denitrification by Ozonation and Possibility of by-Product Separation

Kordylewski

Hałat

Łuszkiewicz

2017

Chemical and Process Engineering

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Results of laboratory scale research have been presented on the effects of an oxidizing reactor on ozone consumption and by-producs composition and separation of simultaneous NOx and SO2 removal from a carrier gas by ozonation method and absorption in an alkaline solution. The additional Dreschel washer added before two washers containing 100 ml of 0.1 molar NaOH solution played the role of an oxidation reactor. Its effect was investigated using an empty (dry or wetted) or filled with packing elements washer. The measured by-products in a scrubber and in the oxidizing reactor were SO3 2-, SO4 2-, NO2 -and NO3 -ions, respectively. It has been shown that use of oxidizing reactor improves NOx removal efficiency reducing ozone consumption. Wetting of the oxidation reactor with water enables a preliminary separation of sulphur and nitrogen species between the oxidizing reactor and an alkaline absorber. Application of packing elements in the oxidizing reactor allows to retain 90% of nitrogen compounds in it. Some results were confirmed by tests in pilot scale.

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Simultaneous absorption of NOx and SO2 from flue gas with pyrolusite slurry combined with gas-phase oxidation of NO using ozone

Cited by 49 publications

References 37 publications

Investigation of Photocatalytic Oxidation and Wet Absorption in a Combined System for Removal of Nitrogen Oxides

Investigation of Photocatalytic Oxidation and Wet Absorption in a Combined System for Removal of Nitrogen Oxides

Study on Separation of Manganese from Iron in High-Iron Pyrolusite Ore by Leaching with Simulated Flue Gas

Influence of Oxidizing Reactor on Flue Gas Denitrification by Ozonation and Possibility of by-Product Separation

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