scholarly journals Study on the removal of NO from flue gas by wet scrubbing using NaClO3

2019 ◽  
Vol 84 (10) ◽  
pp. 1183-1192
Author(s):  
Deqi Shi ◽  
Guoxin Sun ◽  
Yu Cui

In order to remove nitric oxide (NO) from flue gas, from small coal-fired boilers, it is necessary to exploit the cost-effective wet denitration technology. The absorption of NO with sodium chlorate solution was studied. The effects of experimental conditions, such as temperature, NaClO3 concentration, type of acid, mole ratio of NaClO3 to hydrogen ions, on NO removal rate were investigated, and the optimal conditions were established. As the effect of temperature on denitration was related to the type of acid used, the temperature required for sulfuric acid was high, and the temperature required for nitric acid was low. The optimal mole ratio between NaClO3 and the two types of acids was the same. The reaction products were analyzed by ion chromatography. The reacted solution could be recycled after the removal of sodium chloride. The reaction mechanism and the total chemical reaction equation of NaClO3 denitration were deduced. The thermodynamic derivations showed that this oxidation reaction could proceed spontaneously and the reaction was very thorough. NaClO3 exhibited high NO removal efficiency and its denitration cost was much lower than sodium chlorite.

2011 ◽  
Vol 356-360 ◽  
pp. 1118-1121 ◽  
Author(s):  
Qi Zhou ◽  
Qi Yu ◽  
Ling Wei Li ◽  
Wen Xi Yu ◽  
Gang Yu

Desulfurization and Denitrification processes in two pulsed discharge plasma systems (NO/SO2/N2/O2/H2O and NO/SOSubscript text2/NSubscript text2/OSubscript text2) were simulated respectively, and then the removal characteristics of these two gas systems were analyzed. The results show that NO can be completely removed when the residence time is close to 1.3 s and SOSubscript text2 removal rate is 61.5% when the residence time reaches 3 s in a system containing water vapor (HSubscript text2O). When the system does not contain water vapor, NO removal rate is still much high, but SOSubscript text2 removal rate is approximately zero. When OSubscript text2 concentration is increased, NO removal velocity will be faster and the peak of the concentration curve of NOSubscript text2 will be higher. NO removing velocity is much faster in a system containing water vapor than that in a system without water vapor when both systems have almost the same OSubscript text2 concentration.


2017 ◽  
Vol 31 (3) ◽  
pp. 3047-3054 ◽  
Author(s):  
Zhitao Han ◽  
Shaolong Yang ◽  
Xinxiang Pan ◽  
Dongsheng Zhao ◽  
Jingqi Yu ◽  
...  

2014 ◽  
Vol 908 ◽  
pp. 187-190
Author(s):  
Mei Jin ◽  
Guo Xian Yu ◽  
Fang Wang ◽  
Ping Lu

In this work, simultaneous absorption of SO2and NO from N2-NO-SO2simulated flue gas using sodium chlorate as the additive and urea as the reductant was investigated experimentally in a rotating packed bed. In RPB, various rotational speeds, gas flow rates and liquid flow rates were studied by means of the removal efficiency of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions and, at the same time, the removal efficiency of NO exhibited different results under various experimental conditions. The simultaneous NO removal efficiency of 82.45% and the SO2removal efficiency of 99.49% could be obtained under the N2flow rate of 0.5 m3/h, SO2flow rate of 6 mL/min, the NO flow rate of 4 mL/min, the rotational speed of 460 rpm and the absorbent flow rate of 40 L/h.


2014 ◽  
Vol 908 ◽  
pp. 183-186 ◽  
Author(s):  
Hong Guan Wu ◽  
Mei Jin ◽  
Fang Wang ◽  
Guo Xian Yu ◽  
Ping Lu

Performance of simultaneous desulfurization and denitrification from N2-NO-SO2simulated flue gas using sodium chlorite as the additive and urea as the reductant in a rotating packed bed was investigated. In RPB, various rotational speeds, the flow rates of SO2, the flow rates of NO and the liquid flow rates were studied by means of the calculation of the removal efficiencies of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions, while the removal efficiency of NO exhibited different results. A better simultaneous desulfurization and denitrification behavior could be obtained under the conditions of a SO2-NO-N2simulated flue gas with the ratio of SO2/NO/ N2=6:4:8.33(v), a rotational speed of 460 rpm and an absorbent flow rate of 120 L/h.


2019 ◽  
Vol 11 (1) ◽  
pp. 11-21
Author(s):  
Hongrui Sun ◽  
Guanghui Yang ◽  
Tallal Bin Aftab ◽  
Fei Xue ◽  
Zhengguo Xiao ◽  
...  

Abstract The method of micro bubbles is widely applied in the fields of water and soil treatment. A novel treatment method of NO in flue gas through a gas–liquid two-phase system formed by micro bubbles is proposed in this study. The system depends on the generation of hydroxyl radicals. The NO removal performance of the micro gas–liquid dispersion system induced by catalysts and O3 was explored and the reaction pathways were elucidated. Micro bubbles, Fe2+, and Mn2+ in solution improved NO removal performance significantly. Salinity and surfactants affected the removal performance of NO by altering micro bubbles. In the presence of Fe2+, the NO removal rate reached 65.2% at pH 5, 75.8% under 0.5 g/L NaCl and 82.1% under 6 mg/L sodium dodecyl sulfate. In the presence of Mn2+, the NO removal rate reached 69.2% at pH 5, 83.2% under 0.5 g/L NaCl and 92.3% under 6 mg/L sodium dodecyl sulfate. However, in the presence of both Mn2+ and Fe2+, NO conversion rate was 93.2%. The NO removal rate in the presence of O3 was further improved under the same conditions. The study provides the basis for the application and development of micro bubbles in flue gas treatments for NO removal. The results can help to solve the problems of high operating cost, large oxidant consumption, secondary pollution, and high energy consumption in traditional NO removal methods. Graphic abstract


2013 ◽  
Vol 742 ◽  
pp. 323-326 ◽  
Author(s):  
Ji Wu Li ◽  
Zhi Peng Tang ◽  
Jie Yu

The effects of the supply voltage, water flow rate, concentration of H2O2absorption and flue gas flow rate on NO removal rate were studied. The chemical reaction mechanism of NO removal was discussed. It was concluded that the NO removal rate increased the increasing of supply voltage, water flow rate and concentration of H2O2, and decreased with the increasing of the flue gas flow rate on the experimental conditions. On the synergy with corona discharge and H2O2solution oxidation, NO removal rate reached 60.2%.


2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.


2020 ◽  
Vol 82 (8) ◽  
pp. 1635-1642
Author(s):  
Ling Zhou ◽  
Zhongying Xu ◽  
Jie Zhang ◽  
Zhifang Zhang ◽  
Ying Tang

Abstract To seek for efficient Fenton-like oxidation processing for treatment of waste fracturing fluid containing hydroxypropyl guar gum (HPGG), in heterogeneous reaction, five bentonite-supported zero-valent metal catalysts were prepared by liquid-phase reduction. The results showed that the bentonite-supported zero-valent copper exhibited best catalytic performance, attributed to the high dispersion of active sites of zero-valent copper. The effects of the most relevant operating factors (H2O2 concentration, catalyst dosage, temperature and pH) were evaluated in detail. Moreover, the chemical oxygen demand removal rate of HPGG can achieve 76% when the reaction time was selected at 45 min under optimal experimental conditions. The stability evaluation showed that the catalytic performance was almost unaffected after the catalyst was recycled and used once more showing the good stability of the bentonite-supported zero-valent copper in the application process.


2004 ◽  
Vol 126 (2) ◽  
pp. 119-124 ◽  
Author(s):  
O. S. Shokoya ◽  
S. A. (Raj) Mehta ◽  
R. G. Moore ◽  
B. B. Maini ◽  
M. Pooladi-Darvish ◽  
...  

Flue gas injection into light oil reservoirs could be a cost-effective gas displacement method for enhanced oil recovery, especially in low porosity and low permeability reservoirs. The flue gas could be generated in situ as obtained from the spontaneous ignition of oil when air is injected into a high temperature reservoir, or injected directly into the reservoir from some surface source. When operating at high pressures commonly found in deep light oil reservoirs, the flue gas may become miscible or near–miscible with the reservoir oil, thereby displacing it more efficiently than an immiscible gas flood. Some successful high pressure air injection (HPAI) projects have been reported in low permeability and low porosity light oil reservoirs. Spontaneous oil ignition was reported in some of these projects, at least from laboratory experiments; however, the mechanism by which the generated flue gas displaces the oil has not been discussed in clear terms in the literature. An experimental investigation was carried out to study the mechanism by which flue gases displace light oil at a reservoir temperature of 116°C and typical reservoir pressures ranging from 27.63 MPa to 46.06 MPa. The results showed that the flue gases displaced the oil in a forward contacting process resembling a combined vaporizing and condensing multi-contact gas drive mechanism. The flue gases also became near-miscible with the oil at elevated pressures, an indication that high pressure flue gas (or air) injection is a cost-effective process for enhanced recovery of light oils, compared to rich gas or water injection, with the potential of sequestering carbon dioxide, a greenhouse gas.


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