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Characterizing nitric oxide emissions from two typical alpine ecosystems

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Journal of Environmental Sciences 2019年第3期31卷 312-322页

作者： Fei Lin Chunyan Liu Xiaoxia Hu Yongfeng Fu Xunhua Zheng Rui Wang Wei Zhang Guangmin Cao State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC) Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences northwest Institute of Plateau Biology Chinese Academy of Sciences

portion of alpine meadows has been and will continue to be cultivated due to the concurrent increasing demands for animal-and crop-oriented foods and global warming.However, it remains unclear how these long-term changes in land use will affect nitric oxide(no) emission. At a field site with a calcareous soil on the Qinghai-Tibetan Plateau,the authors measured the year-round no fluxes and related variables in a typically wintergrazed natural alpine meadow(NAM) and its adjacent forage oat field(FOF). The results showed that long-term plow tillage, fertilization and growing forage oats significantly yielded ca. 2.7 times more(p no emissions from the FOF than the NAM(conservatively 208 vs. 56 g N/(ha·year) on average). The spring freeze–thaw period and non-growing season accounted for 17%-35% of the annual emissions, respectively. The Q10 of surface soil temperature(Ts) was 8.9 in the NAM(vs. 3.8 in the FOF), indicating increases of 24%–93% in no emissions per 1–3 °C increase. However, the warming-induced increases could be smaller than those due to land use change and management practices. The Tsand concentrations of ammonium, nitrate and water-extractable organic carbon jointly explained 69% of the variance in daily no fluxes from both fields during the annual period(p no fluxes from landscapes with calcareous soils across native alpine meadows and/or fields cultivated with forage oats can be predicted by simultaneous observations of these four soil variables.

关键词： Alpine meadow Annual no fluxes non-growing season Freeze–thaw period Land use change Global warming

Superior activity of iron–manganese supported on kaolin for no abatement at low temperature

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Journal of Environmental Sciences 2020年第2期32卷 237-247页

作者： Xiaobo Wang Jie Zhou Tong Zhao Keting Gui Jia Wang Hywel RThomas School of Environmental Science Nanjing Xiaozhuang UniversityNanjing 211171China Geoenvironmental Research Centre School of EngineeringCardiff UniversityCardiff CF243AAUK School of Energy and Environment Southeast UniversityNanjing 210096China College of Chemical Engineering Nanjing Forestry UniversityNanjing 210037China

A series of Fe–Mn catalysts was prepared using different supports(kaolin, diatomite, and alumina) and used for no abatement via low-temperature NH3-selective catalytic reduction(SCR).The results showed that 12 Fe–10 Mn/Kaolin(with the concentration of Fe and Mn 12 and 10 wt.%, respectively) exhibited the highest activity, and more than 95.8% no conversion could be obtained within the wide temperature range of 120–300℃.The properties of the catalysts were characterized by inductively coupled plasma-atomic emission spectrometry(ICP-AES), thermogravimetry(TG), Brunner–Emmet–Teller(BET)measurements, X-ray diffraction(XRD), H2-temperature programmed reduction(H2-TPR),NH3-temperature programmed desorption(NH3-TPD), X-ray photoelectron spectroscopy(XPS), scanning electron microprobe(SEM) and energy dispersive spectroscopy(EDS)techniques.The support effects resulted in significant differences in the components and structures of catalysts.The 12 Fe–10 Mn/Kaolin catalyst exhibited better dispersion of active species, optimum low-temperature reduction behavior, the largest amount of normalized Br?nsted acid sites, and the highest Mn4+/Mn and Fe3+/(Fe3++ Fe2+), all of which may be major reasons for its superior catalytic activity.

关键词： Kaolin Low-temperature Iron-based catalysts no abatement

Effect of CeO_2 and Al_2O_3 on the activity of Pd/Co_3O_4/cordierite catalyst in the three-way catalysis reactions(CO/no/C_nH_m)

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Journal of Environmental Sciences 2012年第7期24卷 1327-1333页

作者： Sergiy O.Soloviev Pavlo I.Kyriienko Nataliia O.Popovych L.V.Pisarzhevsk Institute of Physical Chemistry National Academy of Sciences of Ukraine

The present article studies the effect of CeO2 and A1203 on the activity of Pd/Co304/cordierite catalyst in conversion of no, CO, CnHm. The catalysts were characterized by temperature programmed reduction with hydrogen, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. It is shown that the effect of CeO2 on the properties of Pd/C03 O4/cordierite catalyst depends on preparation method. The catalyst obtained by co-deposition of cerium and cobalt oxides has higher activity in CO oxidation （CO ＋ 02 and CO ＋ no） and total hexane oxidation （C6H14 ＋ 02）. Such phenomenon is probably caused by more than stoichiometric amount of formed oxygen vacancies, an increase in both mobility of surface oxygen and dispersity of components in the catalytic composition. It is demonstrated that CeO2 addition promotes the SO2 resistance of Pd/C03 O4/cordierite. The second support decreases the activity of Pd/Co3Oa/cordierite catalyst in the reactions of CO and C6H14 with oxygen because of COA1204 formation.

关键词： metal-oxide catalysts structured catalysts effect of CeO2 and A1203 CO no CnH,. conversion

Cu-SAPO-44选择性催化丙烯还原no性能研究

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燃料化学学报 2022年第8期50卷 1064-1074页

作者：张恒周皞温妮妮王旭瑞徐璐苏亚欣东华大学环境科学与工程学院上海201620 常州工程职业技术学院江苏常州213164

以环己胺(CHA)和铜胺络合物(Cu-TEPA)为共模板剂,一步水热合成Cu-SAPO-44分子筛催化剂,用于贫燃条件下选择性催化丙烯还原no(C_(3)H_(6)-SCR)。采用N_(2)吸附-脱附、X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见光谱(UV-vis)、NH_(3... 详细信息

以环己胺(CHA)和铜胺络合物(Cu-TEPA)为共模板剂,一步水热合成Cu-SAPO-44分子筛催化剂,用于贫燃条件下选择性催化丙烯还原no(C_(3)H_(6)-SCR)。采用N_(2)吸附-脱附、X射线衍射(XRD)、透射电子显微镜(TEM)、紫外可见光谱(UV-vis)、NH_(3)程序升温脱附(NH_(3)-TPD)和H_(2)程序升温还原(H_(2)-TPR)等方法对催化剂进行表征。与纯SAPO-44相比,Cu-TEPA的引入显著增强了分子筛的C_(3)H_(6)-SCR催化活性。当Cu/Al=0.25时,Cu-SAPO-44催化剂有着最大的比表面积、丰富的酸性位和较多的孤立Cu^(2+)物种,具有最佳的脱硝性能。随着Cu-TEPA引入量的增加,铜物种会在分子筛表面聚集,生成相对较多无活性的CuO,从而降低了脱硝活性。原位红外光谱(In situ DRIFTS)研究表明,孤立的Cu^(2+)有助于no和C_(3)H_(6)的吸附和活化,促进反应关键中间产物−NCO形成。50 h的持久性反应测试表明,Cu-SAPO-44催化剂始终保持>60%的no_(x)转化率和>90%的N_(2)选择性,表现出良好的反应稳定性。

关键词： Cu-SAPO-44 选择性催化还原 no C3H6-SCR

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水洗预处理对白酒糟燃料性质及燃烧特性影响

中国电机工程学报 2022年第20期42卷 7554-7562页

作者：朱小超张永刚张自强李健周生权李宁颜蓓蓓陈冠益天津大学环境科学与工程学院天津市南开区300350 中节能绿碳环保有限公司北京市海淀区100082 天津商业大学机械学院天津市北辰区300134

水洗预处理技术对生物质燃烧利用具有重要意义。在不同含固率、洗糟水条件下对白酒糟进行水洗预处理,通过工业分析、元素分析、以及热重-质谱联用(thermogravimetric-mass spectrometry,TG-MS)分析等手段,探究了水洗预处理对酒糟燃料性... 详细信息

水洗预处理技术对生物质燃烧利用具有重要意义。在不同含固率、洗糟水条件下对白酒糟进行水洗预处理,通过工业分析、元素分析、以及热重-质谱联用(thermogravimetric-mass spectrometry,TG-MS)分析等手段,探究了水洗预处理对酒糟燃料性质及燃烧特性的影响。研究结果表明:水洗分离预处理对白酒糟物化性质有显著影响,随着含固率增大,灰分含量降低,挥发分含量升高,而固定碳在含固率8%时出现峰值。水洗分离后酒糟碳含量得到一定程度的富集,氧含量在含固率大于8%时有所减少;氮、硫含量降低;高位热值有小幅提升。因此水洗可以有效改善酒糟燃料性质。水洗后的酒糟在燃烧过程中永久性气体(H_(2)O、CO_(2)、NH_(3)、no)释放量均减小;在含固率为5%时,NH_(3)减排56.6%,no减排达33.1%。此外,水洗分离酒糟可以有效缓解酒糟燃烧的污垢结渣倾向。酿酒废水与等量自来水的处理效果明显不同。本研究证明了水洗分离处置技术应用于白酒糟的可行性,同时为高效清洁处置工业废弃生物质提供一条新思路。

关键词：水洗含固率白酒糟燃烧 no 结渣热重-质谱

不同热解活化条件下制备的污泥炭常温催化氧化no

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燃料化学学报 2022年第3期50卷 366-375页

作者：周易邓文义胡明涛许铈尧苏亚欣东华大学环境科学与工程学院上海201620

以市政污泥为原料制备污泥炭(SC),开展了SC常温催化氧化no的实验研究。通过对不同热解温度(600、700和800℃)和不同干基污泥(DS)/KOH混合质量比下(4∶1、3∶1、2∶1和1∶1)的no脱除特性研究,探究了污泥裂解活化工艺对no常温催化氧化的... 详细信息

以市政污泥为原料制备污泥炭(SC),开展了SC常温催化氧化no的实验研究。通过对不同热解温度(600、700和800℃)和不同干基污泥(DS)/KOH混合质量比下(4∶1、3∶1、2∶1和1∶1)的no脱除特性研究,探究了污泥裂解活化工艺对no常温催化氧化的影响规律和作用机理。结果表明,热解温度和KOH活化均对SC的催化活性有显著影响,当热解温度由600℃升至800℃,裂解样的no转化率由12%升至36%;不同热解温度下,SC的催化活性均随KOH用量增加呈先增大后减小趋势;当热解温度为700℃、DS/KOH=3∶1时,SC的催化活性最优,达到56%;对该样品进一步进行氢气还原处理后,其脱硝效率进一步提升,达到76.5%。研究发现,SC的催化活性与其比表面积有强相关性,其反应机理遵循Eley-Rideal(E-R)模型。

关键词： no 催化氧化污泥炭 KOH活化热解

Role of no in Hg^0 oxidation over a commercial selective catalytic reduction catalyst V_2O_5–WO_3/TiO_2

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Journal of Environmental Sciences 2015年第12期27卷 126-132页

作者： Ruihui Liu Wenqing Xu Li Tong Tingyu Zhu Research Center for Process Pollution Control National Engineering Laboratory for Hydrometallurgical Cleaner Production TechnologyInstitute of Process EngineeringChinese Academy of Sciences Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at Qinhuangdao Branch

Experiments were conducted in a fixed-bed reactor that contained a commercial catalyst,V2O5-WO3/TiO2,to investigate mercury oxidation in the presence of no and O2.Mercury oxidation was improved by no,and the efficiency was increased by simultaneously adding no and O2.With no and O2 pretreatment at 350°C,the catalyst exhibited higher catalytic activity for Hg^0 oxidation,whereas no pretreatment did not exert a noticeable effect.Decreasing the reaction temperature boosted the performance of the catalyst treated with no and O2.Although no promoted Hg^0 oxidation at the very beginning,excessive no counteracted this effect.The results show that no plays different roles in Hg^0oxidation; no in the gaseous phase may directly react with the adsorbed Hg^0,but excessive no hinders Hg^0 adsorption.The adsorbed no was converted into active nitrogen species（e.g.,no2） with oxygen,which facilitated the adsorption and oxidation of Hg^0.Hg^0 was oxidized by no mainly by the Eley-Rideal mechanism.The Hg^0 temperature-programmed desorption experiment showed that weakly adsorbed mercury species were converted to strongly bound ones in the presence of no and O2.

关键词： Mercury no Mechanism Selective catalytic reduction catalyst Oxidation Vanadium

Emissions of SO_2, no and N_2O in a circulating fluidized bed combustor during co-firing coal and biomass

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Journal of Environmental Sciences 2007年第1期19卷 109-116页

作者： XIE Jian-jun YANG Xue-min ZHANG Lei DING Tong-li SONG Wen-li LIN Wei-gang Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

This paper presents the experimental investigations of the emissions of SO2, no and N20 in a bench scale circulating fluidized bed combustor for coal combustion and co-firing coal and biomass. The thermal capacity of the combustor is 30 kW. The setup is electrically heated during startup. The infuence of the excess air, the degree of the air staging, the biomass share and the feeding position of the fuels on the emissions of SO2, no and N2O were studied. The results showed that an increase in the biomass shares resulted in an increase of the CO concentration in the flue gas, probably due to the high volatile content of the biomass. In co-firing, the emission of SO2 increased with increasing biomass share slightly, however, non-linear increase relationship between SO2 emission and fuel sulfur content was observed. Air staging significantly decreased the no emission without raising the SO2 level. Although the change of the fuel feeding position from riser to downer resulted in a decrease in the no emission level, no obvious change was observed for the SO2 level. Taking the coal feeding position R as a reference, the relative no emission could significantly decrease during co-firing coal and biomass when feeding fuel at position D and keeping the first stage stoichiometry greater than 0.95. The possible mechanisms of the sulfur and nitrogen chemistry at these conditions were discussed and the ways of simultaneous reduction of SO2, no and N2O were proposed.

关键词： circulating fluidized bed （CFB） combustion SO2 no N2O co-firing biomass

氨煤混燃过程中NH/煤焦/O_(2)异相体系N氧化的分子机理

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煤炭学报 2023年第2期48卷 1037-1046页

作者：陈萍王莹汪辉春蒋博宇顾明言樊建人安徽工业大学能源与环境学院安徽马鞍山243002 浙江大学能源清洁利用国家重点实验室浙江杭州310000

为了实现双碳目标,降低煤电碳排放势在必行。无碳燃料氨与煤混烧被认为是降低火电碳排放的有效途径之一。而氨作为N源,增加了氨煤混燃nox排放量升高的可能性,因此,深入研究氨煤混燃no生成机理对实现氨煤混燃低碳低氮燃烧十分关键。采用... 详细信息

为了实现双碳目标,降低煤电碳排放势在必行。无碳燃料氨与煤混烧被认为是降低火电碳排放的有效途径之一。而氨作为N源,增加了氨煤混燃nox排放量升高的可能性,因此,深入研究氨煤混燃no生成机理对实现氨煤混燃低碳低氮燃烧十分关键。采用量子化学方法探究了当NH3以NH形式存在时氨煤混燃N的氧化机理,并采用波函数分析NH和O_(2)在煤表面的吸附行为。计算结果表明,NH在C5表面吸附形成中间体IM1的过程为放热过程,放热量高达754.79 kJ/mol,且C原子为电子供体而失电子,NH为电子受体而得电子,促进C—N键键合。进一步探究O_(2)以不同方式吸附时NH/煤焦/O_(2)体系的反应机理,得出NH/煤焦/O_(2)共燃体系首先发生NH在煤焦表面的氧化,随后煤焦表面残余氧或体系中O_(2)将煤焦-N进一步氧化。NH/煤/O_(2)异相体系中NH通过不同反应路径生成氧化产物no、no_(2)和Hno,对应决速步能垒分别为120.67、323.37和193.50 kJ/mol,说明氨-N/煤-N生成no的过程更易进行。动力学结果表明,各温度下生成no的决速步速率明显高于no_(2),且随着温度升高,生成no的决速步速率与Hno的逐渐接近。NH氧化产物释放后,残留在煤焦表面氧进一步与C结合成CO释放,实现了共燃体系氨燃料中N和煤粉中C的氧化。随后煤焦-N与体系中O_(2)发生异相氧化,实现煤焦-N向no的转化。在微观层面揭示了氨燃烧生成no过程中重要过渡产物Hno形成的分子机理,明晰了另一氧化产物no_(2)的生成路径,为发展氨煤的混合燃烧机理提供理论支撑和数据参考。

关键词：氨煤混烧 NH 煤焦-N no Hno