ChemistrySelect
·
2024
·Vol. 9
·期 28
·e202401039
·
IF 1.9
Xueqi Wang,Kai Li,Fei Wang,Lei Shi,Shuangyou Bao,Jiacheng Bao,Xin Sun
Graphical In this study, we prepared the thermally modified copper slag catalyst CS-CaO-900 and applied it to a pilot-scale Fenton-like denitrification system. In single-factor experiments, the effects of six factors, namely inlet NO concentration, H 2 O 2 concentration, catalyst dosage, reaction temperature, L/G ratio, and pH value, on desulfurization and denitrification were investigated. Through analysis of the experimental results, the three factors that had the greatest impact on the maximum denitrification efficiency, namely pH value, H 2 O 2 concentration, and reaction temperature, were selected. The response surface methodology was employed to investigate the significance of the three factors and optimize the parameters, and it was finally determined that the initial pH of the slurry had the greatest impact on the maximum denitrification efficiency, followed by the H 2 O 2 concentration. At the same time, the combination of initial slurry pH and reaction temperature, initial slurry pH and H 2 O 2 concentration also had a large impact on the maximum denitrification efficiency, and the combination of reaction temperature and H 2 O 2 concentration had a non-significant impact on the denitrification efficiency. And through the model optimization to get the best parameters, denitrification experiments under this parameter to achieve the maximum denitrification efficiency of 91.5 %, for further industrial application to provide reference and guidance. In this study, Response Surface Methodology (RSM) was employed to optimize the experimental factors influencing the simultaneous removal of NOx and SO 2 in a spray tower wet scrubbing experiment. Thermally modified copper slag (CS-CaO-900) was prepared by heat treating the original copper slag. The performance of CS-CaO-900 in the synchronized removal of NOx and SO 2 was then evaluated in an expanded experimental setup. Based on single-factor experimental results, the Box-Behnken design of RSM was used to optimize the reaction parameters in a two-stage sequential reactor (bubbling reactor + spray tower). NOx removal efficiency was modeled as a function of reaction temperature, pH, and H 2 O 2 concentration. Regression curves provided a visual representation of the interaction effects among these parameters on NOx removal efficiency in the thermally modified copper slag/H 2 O 2 composite slurry. This study elucidates the characteristics of each parameter under wet scrubbing conditions and provides essential data for industrial applications.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Haotian Li,Feng Liu,Shuhui Wang,Fengjia Wang,Xin Qian,Caiduan Zhang,Yongliang Ma,Lidong Wang
Based on advanced oxidation technology, a new method for the simultaneous removal of SO 2 and NO x from industrial flue gas using Na 2 S 2 O 8 /MgO was proposed. The method does not require the body structure of the wet desulfurization device is changed but adds Na 2 S 2 O 8 to the original equipment to realize simultaneous desulfurization and denitrification. After determining Cl − was additive, the effects of various reaction factors on the simultaneous removal of SO 2 and NO x were investigated, including the Cl − concentration, the initial concentration of the oxidant, the initial pH value of the solution, and the reaction temperature. According to the characterization of removal products and the types of free radicals involved in the reaction by XRD , XPS , and EPR , the reaction mechanism was elucidated. The experimental results indicated that the removal products were mainly sulfates and nitrates. The free radicals involved in the reaction were SO 4 ·− , ·OH, and Cl·, and the key free radical was Cl·.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Peng Lu,Xianhui Yan,Lyumeng Ye,Dingsheng Chen,Dongyao Chen,Jianhang Huang,Chaoping Cen
The co-removal of CO 2 while removing SO 2 and NO x from industrial flue gas has great potential of carbon emission reduction but related research is lacking. In this study, a wet scrubbing process with various urea solutions for desulfurization and denitrification was explored for the possibility of CO 2 absorption. The results showed that the urea-additive solutions were efficient for NO x and SO 2 abatement, but delivered < 10% CO 2 absorption efficiency. The addition of Ca(OH) 2 dramatically enhanced the CO 2 absorption, remained the desulfurization efficiency, unfortunately restricted the denitrification efficiency. Among various operating parameters, pH of solution played a determining role during the absorption. The contradictory pH demands of CO 2 absorption and denitrification were observed and discussed in detail. A higher pH of solution than 10 was favorable for CO 2 absorption, while the oxidizing of NO to NO 2 , NO 2 − or NO 3 − by NaClO 2 was inhibited in this condition. When 7 < pH < 10, it was favorable for the conversion and absorption of NO and NO x . However, the conversion of HCO 3 − to CO 3 2− was significantly inhibited, hence preventing the absorption of CO 2 . Large part of Ca(OH) 2 became CaCO 3 with a finer particle size, which covered the unreacted Ca(OH) 2 surface after the reaction. Kinetic analysis showed that the CO 2 absorption in urea-NaClO 2 -Ca(OH) 2 absorbent was controlled by chemical reaction in early stage, then by ash layer diffusion in later stage.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Junqi Cheng,Zhitao Han,Jiawei Li,Xinxiang Pan
Previous work proposed a one-stage wet scrubbing in situ combined with O3 oxidation for simultaneous removal of NO and SO2 from flue gas, and the results showed that wet scrubbing combined in situ with O3 injection could effectively improve O3 oxidant utilization efficiency. In this work, a follow-up research work was carried out to further explore the synergistic effect of dual oxidants of NaClO in the liquid phase and O3 in gas phase. The synergistic effects of O3/NO molar ratio and NaClO concentration in the circulating scrubbing solution on NOx removal performance was investigated systematically. The results showed that when molar ratio of O3/NO was 0.5 and NaClO concentration was 25 mM, NO could be oxidized completely and averaged NOx removal efficiency exceeded 70%. NOx concentrations in outlet gas and anion compositions in the scrubbed solution were analyzed, and the possible reaction paths of wet scrubbing NaClO solution in situ with O3 injection in denitration process were also discussed. When the solution pH was around 6, a relative balance between NOx oxidation and absorption might be achieved, resulting in a high NOx removal efficiency. The temperature of inlet flue gas imposed little impact on NOx removal efficiency due to the quick and efficient cooling effect by wet scrubbing. The increase of initial SO2 concentration led to a slight increase of NOx removal efficiency from 70 to 73.5%. A complete removal of SO2 could be achieved, but coexisting SO2 in flue gas would consume NaClO oxidant and shorten the reaction duration.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
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2019
·
IF 3.021
Zhitao Han,Tian Lan,Zhiwei Han,Shaolong Yang,Jingming Dong,Deping Sun,Zhijun Yan,Xinxiang Pan,Liguo Song
Experiments were conducted to simultaneously remove NO and SO2 from simulated exhaust gas by cyclic scrubbing and online supplementing pH-buffered NaClO2 solutions in a bench-scale reactor. The effects of key operating parameters on pollutant removal performance had been investigated. The results suggested that an extremely high oxidant utilization rate could be obtained when the oxidant supplementing molar rate approached the oxidant consumption molar rate. Though co-existing SO2 in flue gas would consume a certain amount of the oxidant during the absorption process, the intermediate products of SO32– ions generated from SO2 hydrolysis might be in favor of NO2 absorption to some extent. The introduction of ethanol in scrubbing solution could enhance NOx removal performance largely, which was possibly because of its inhibition effect on SO32– oxidation. The reaction mechanism and reaction products in scrubbing solutions were also discussed roughly through theoretical calculations and ion chromatography analysis.
研究领域:
环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Zijian Song,Ben Wang,Wu Yang,Tao Chen,Chuan Ma,Lushi Sun
Fe 2.5 M 0.5 O 4 (M = Mn, Ti and Cu) were investigated for the first time as the catalyst for simultaneous removal of NO and SO 2 through catalytic oxidation-absorption with vaporized H 2 O 2 . The physicochemical properties of as-prepared catalysts were comprehensively characterized by XRD, SEM, TEM, BET, XPS, TPR, VSM, TG and PL analyses. Activity test results showed that SO 2 can be completely removed under most conditions. However, NO removal was affected by catalyst, H 2 O 2 consumption, reaction temperature, GHSV and coexistence gases (i.e., H 2 O, O 2 , NO and SO 2 ). Mn, Ti and Cu doping in the magnetite can remarkably enhance NO removal. Redox pairs and oxygen vacancy of catalysts were considered as vital factors affecting OH generation. Base on the catalyst characterization and DFT calculation results, the main mechanism of Mn, Ti and Cu doping on the catalytic activity improvement was explained as follows: (a) Mn, Ti and Cu doping can increase the catalyst surface area; (b) Ti on the surface can directly promote the catalytic decomposition of H 2 O 2 ; and (c) Mn and Cu doping can promote the generation of oxygen vacancy and indirectly increase the activity. Moreover, two arrangement forms of an industrial simultaneous removal system for NO, SO 2 and Hg 0 were proposed.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 30
·18500-18507
·
IF 3.108
Xuecheng Liu,Yugo Osaka,Hongyu Huang,Jun Li,Zhaohong He,Xixian Yang,Huhetaoli,Shijie Li,Noriyuki Kobayashi
Increasing concern about sulfur dioxide (SO2) from diesel vehicle exhausts causing detrimental effects on NOx removal catalysts has resulted in the development of dry desulfurization filters for complete removal of SO2. In this study, a compact MnO2 filter was developed for diesel emission control. The SO2-capture behavior of the compact MnO2 filter was investigated by using a volumetric device in a low temperature range (200–400 °C) and low SO2 pressure conditions. The maximal capacity of the MnO2 filter was 304.1 mgSO2 per gMnO2 at 400 °C. Based on the experimental results, the required volume of the MnO2 filter was estimated as only 0.6 L for a diesel car with 30 000 km distance traveled per year. The thickness of the MnO2 filter had significant influence on its SO2-capture performance. The sulfate reaction mechanism was also discussed by using a grain model under four reaction temperature conditions for improving the efficiency of the design of the desulfurization filter. The sulfate process can be divided into two control stages (the chemical reaction control stage and the solid diffusion control stage) and the prediction models fit the experimental data well for both control stages, indicating that the two-stage grain model is suitable for the sulfate reaction between the MnO2 filter and SO2. The calculated apparent activation energy of 18.8 kJ mol−1 indicates that the MnO2 filter exhibits high activity for SO2 adsorption in a pure SO2 atmosphere.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Hongyuan Xi,Song Zhou,Jinxi Zhou,Zhao Zhang
The novel combined system using Na 2 S 2 O 8 /urea was used to simultaneously absorb nitric oxide and sulfur dioxide emissions from marine diesel engines as well as inhibit the formation of nitrate in cleaning wastewater to meet the increasingly stringent requirements of regulations. The influences of reaction temperature, Na 2 S 2 O 8 concentration, urea concentration, SO 2 concentration, NO concentration and pH value on SO 2 removal efficiency, NO removal efficiency and nitrate concentration were investigated. The experimental results showed that different reaction temperatures had different influences on SO 2 removal efficiency, NO removal efficiency and nitrate concentration. An increase in Na 2 S 2 O 8 could improve the absorption of NO. The addition of urea could effectively improve the removal efficiency of NO and reduce the nitrate concentration. The removal efficiencies of 1000 ppm NO and 1000 ppm SO 2 achieved 100 % with 0.2 mol/L Na 2 S 2 O 8 and 2 mol/L urea at 70℃, and the nitrate content was 8.56 mg/L which was far lower than the regulatory requirement of 60 mg/L. The acidic condition (pH ≤ 5.5) not only facilitated the absorption of NO but also reduced the generation of nitrate. According to the experimental results, the novel combined system was promising to be applied to the control technology of marine diesel engine exhaust.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zihao Gao,Yongjun Jiang,Zheyi Sun,Bin Shao,Rongting Ma,Zhonghao Jia,Lihui Zhou,Sheng Dai,Jun Hu
Integrated CO 2 capture and conversion (iCCC) technology has been recognized as the most efficient technology for Carbon Capture, Utilization, and Storage (CCUS). However, its industrialization is hindered by some unsolved engineering problems. Typically, sulfur impurities in most industrial flue gas will have significant poisoning effects on the process. Herein, we report integrations of SO 2 removal, CO 2 capture and conversion (iSCCC) at an isothermal intermediate temperature in a two-fixed-bed column system. By rationally developing the SO 2 adsorbent pellets of ZnO-CaO, the CO 2 adsorbent pellets of AMS-MgO, and the methanation catalyst pellets of Ni-La/Al 2 O 3 , each individual unit is optimized. Specifically, the in-situ dynamic structure evolution observed by the atmospheric aberration-corrected scanning transmission electron microscopy as well as the theoretical dynamics calculation provide an in-depth understanding of the CO 2 desorption performance changing with the temperature on the AMS-MgO pellets, which builds a bridge for a successful 99.3 % CO 2 methanation efficiency. As a result, the matched iSCCC process demonstrates exceptional performance from simulated flue gas containing 1000 ppm SO 2 and 20 vol% CO 2 , with full desulfurization and decarbonation and a CO 2 conversion efficiency of 93.6 % after 20 cycles isothermally at 400 °C, superior to all the reported performance so far as we know, providing a promising route to practical large-scale iSCCC towards carbon neutrality.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Yan Zhang,Zhonghang Chen,Xing Liu,Ze Dong,Peixin Zhang,Jun Wang,Qiang Deng,Zheling Zeng,Shuhua Zhang,Shuguang Deng
Removal of trace SO2 contaminants from gas mixtures by the molecular sieving effect is highly desired. Herein, a microporous metal–organic framework Cu2(pzdc)2(pyz) [CPL-1, pzdc = 2,3-pyrazinedicarboxylate; pyz = pyrazine] with a dumbbell-shaped 1D channel and specific binding sites is explored for deep desulfurization. The proper size of 4.1 × 6.2 Å and strong SO2 trapping sites on CPL-1 render a high adsorption uptake of SO2 (44.8 cm3 g–1) with a record-high selectivity for SO2/N2 (368) and SO2/CH4 (74.3) separation under ambient conditions. Moreover, the dispersion-corrected density functional theory calculations have identified the dual specific adsorption sites of SO2, such as Sδ+···Oδ− electrostatic interactions and Oδ−···Hδ+ hydrogen bonds. The feasibility of CPL-1 for SO2/N2, SO2/CH4, CO2/CH4, CO2/N2, and mimicked flue gas mixture separations was validated by dynamic breakthrough experiments. Water vapor and CO2 impurity were introduced to the gas feed streams to confirm the excellent separation performance of CPL-1. Moreover, a scale-up production of CPL-1 via a facile and green method was conducted, and a reproducible CPL-1 adsorbent with undamaged adsorption and separation performances was successfully manufactured in kilogram quantity. These unique features render CPL-1 a very promising adsorbent for practical desulfurization processes.
研究领域:
化学
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）