scholarly journals Pilot-scale studies on NOx removal from flue gas via NO ozonation and absorption into NaOH solution

2012 ◽  
Vol 33 (3) ◽  
pp. 345-358 ◽  
Author(s):  
Maciej P. Jakubiak ◽  
Keyword(s):  
Flue Gas ◽  
Experimental Studies ◽  
Pilot Scale ◽  
No Oxidation ◽  
Molar Ratio ◽  
Nox Removal ◽  
Gas Channel ◽  
Wet Scrubbing ◽  
Naoh Solution ◽  
Gas Ratio

Abstract The paper presents results of experimental studies on removal of NOx from flue gas via NO ozonation and wet scrubbing of products of NO oxidation in NaOH solutions. The experiment was conducted in a pilot plant installation supplied with flue gas from a coal-fired boiler at the flow rate 200 m3/h. The initial mole fraction of NOx,ref in flue gas was approx. 220 ppm, the molar ratio X = O3/NOref varied between 0 and 2.5. Ozone (O3 content 1÷5% in oxygen) was injected into the flue gas channel before the wet scrubber. The effect of the mole ratio X, the NaOH concentration in the absorbent, the liquid-to-gas ratio (L/G) and the initial NOx concentration on the efficiency of NOx removal was examined. Two domains of the molar ratio X were distinguished in which denitrification was governed by different mechanisms: for X ≤ 1.0 oxidation of NO to NO2 predominates with slow absorption of NO2, for X >> 1.0 NO2 undergoes further oxidation to higher oxides being efficiently absorbed in the scrubber. At the stoichiometric conditions (X = 1) the effectiveness of NO oxidation was better than 90%. However, the effectiveness of NOx removal reached only 25%. When ozonation was intensified (X ≥ 2.25) about 95% of NOx was removed from flue gas. The concentration of sodium hydroxide in the aqueous solution and the liquid-to-gas ratio in the absorber had little effect on the effectiveness of NOx removal for X > 2.

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

2017 ◽  
Vol 38 (1) ◽  
pp. 177-191
Author(s):  
Włodzimierz Kordylewski ◽  
Adam Hałat ◽  
Dariusz Łuszkiewicz
Keyword(s):  
Flue Gas ◽  
Pilot Scale ◽  
Product Separation ◽  
Naoh Solution ◽  
Preliminary Separation ◽  
Nox Removal Efficiency ◽  
Oxidation Reactor ◽  
By Products ◽  
Flue Gas Denitrification

Abstract 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 SO32-, SO42-, 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.

Experimental Study on Simultaneous Desulfurization and Denitrification by Ozone Oxidation Combined with Alkaline Wastewater Washing

2014 ◽  
Vol 1010-1012 ◽  
pp. 748-755
Author(s):  
Hua Yin ◽  
Hua Fang Guo
Keyword(s):  
Water Level ◽  
Flue Gas ◽  
Oxidation Rate ◽  
Removal Rate ◽  
No Oxidation ◽  
Molar Ratio ◽  
Gas Temperature ◽  
Ozone Oxidation ◽  
Alkaline Water ◽  
Water Rate

It is important to develop low cost and efficient technique for simultaneous removal of SO2and NOXfrom flue gas. In this paper, ozone oxidation and alkaline wastewater washing process was employed for flue gas desulfurization and denitrification in a 75t/h coal-fired boiler. In order to optimize the operation parameters for SO2and NOXremoval, the influence of several parameters, such as molar ratio of [O3]/[NO] and flue gas temperature on the oxidation rate of NO, oxidation rate of NO, alkaline water level in aeration tank, alkaline water rate and mole ratio of [NaOH/ (SO2+NOx)] on the removal efficiency of SO2and NOXhave been studied. The experimental results showed that molar ratio of [O3]/[NO] had limited effect on the oxidation of SO2, while NO oxidation efficiency improved with the increase of [O3/NO] molar ratio and it reached to ~ 90% at molar ratio of [O3]/[NO] = 1.4. Flue gas temperature performed slight influence on the oxidation of NO in the range of 60 to 120 °C, and had adverse impact on the removal of SO2and NOX. NOXremoval rate was enhanced with increasing NO oxidation rate and achieved to a high level at NO oxidization rate of ~50%. Mole ratio of [NaOH/ (SO2+NOx)] had significant impact on the removal rate of NOX, while it showed limited effects on that of SO2. The increase of alkaline aeration water level and alkaline water rate would definitely lead to a higher removal rate for both SO2and NOX. An optimized removal rate of 93.6% for SO2, 77.6% for NOXand 99.1% for dust were obtained under the water level of 20cm and volume of 74.5t/h.

scholarly journals Experimental Study on Simultaneous Desulfurization and Denitrification by DBD Combined with Wet Scrubbing

2021 ◽  
Vol 11 (18) ◽  
pp. 8592
Author(s):  
Liang Yang ◽  
Yunkai Cai ◽  
Lin Lu
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Flue Gas ◽  
Mass Fraction ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Spray Density ◽  
Wet Scrubbing ◽  
Naoh Solution ◽  
Dbd Reactor

A dielectric barrier discharge (DBD) reactor combined with a wet scrubbing tower was used to carry out an experimental study on desulfurization and denitrification. The effects of the packing type, packing height, spray density, mass fraction of the NaOH solution, discharge power in the DBD reactor, and simulated flue gas flow rate on the desulfurization and denitrification efficiency were analyzed, along with the influence weight of each factor, using orthogonal testing. The experimental results showed that SO2 was easily absorbed by the scrubbing solution, while the desulfurization efficiency remained at a high level (97–100%) during the experiment. The denitration efficiency was between 12 and 96% under various operating conditions. Denitration is the key problem in this system. The influence weights of the DBD power, simulated flue gas flow rate, mass fraction of the NaOH solution, spray density, packing type, and packing height on the denitration efficiency were 56.96%, 18.02%, 11.52%, 5.02%, 4.33%, and 4.16%, respectively. This paper can provide guidance to optimize the desulfurization and denitrification efficiency of this DBD reactor combined with a wet scrubbing system.

scholarly journals Pilot Plant Studies on Nox Removal Via No Ozonation and Absorption

2013 ◽  
Vol 39 (3) ◽  
pp. 93-106 ◽  
Author(s):  
Włodzimierz Kordylewski ◽  
Maciej Jakubiak ◽  
Tomasz Hardy
Keyword(s):  
Flow Rate ◽  
Flue Gas ◽  
Pilot Plant ◽  
Molar Ratio ◽  
Experimental Investigations ◽  
Oxidizing Agent ◽  
Nox Removal ◽  
Complete Conversion ◽  
Air Flow Rate ◽  
Oxidation Of No

Abstract The results of experimental investigations on the removal of NOx from gases applying ozone as the oxidizing agent and the absorption of higher nitrogen oxides in the sodium hydroxide solutions are presented. The experiment was conducted using a pilot plant installation with the air flow rate 200 m3/h, being a prototype of a boiler flue gas duct and a FGD scrubber. It was shown that in the range of [NOref] = 50 ÷ 250 ppm the mechanism of NO ozonation depends on the molar ratio X = O3/NOref: for X ≤ 1.0 oxidation of NO to NO2 predominates and NO2 is poorly absorbed, for X >> 1.0 NO2 undergoes further oxidation to N2O5, which is efficiently absorbed in the scrubber. The stoichiometric molar ratio of complete conversion of NO into N2O5 is X = 1.5, in these studies to reach the effectiveness η ≥ 90% the molar ratio X was much higher (2.75).

Evaluation of NOx removal from flue gas and Fe(II)EDTA regeneration using a novel BTF–ABR integrated system

2021 ◽  
pp. 125741
Author(s):  
Yanling Wang ◽  
Jianjun Li ◽  
Shaobin Huang ◽  
Xingzhu Huang ◽  
Wenzhe Hu ◽  
...  
Keyword(s):  
Flue Gas ◽  
Integrated System ◽  
Nox Removal

A study on kinetics of NO absorption from flue gas by using UV/Fenton wet scrubbing

2012 ◽  
Vol 197 ◽  
pp. 468-474 ◽  
Author(s):  
Yangxian Liu ◽  
Jun Zhang ◽  
Zhuliang Wang
Keyword(s):  
Flue Gas ◽  
Wet Scrubbing ◽  
Kinetics Of ◽  
No Absorption

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

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