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Empirical modeling of normal/cyclo-alkanes pyrolysis to produce light olefins

Chinese Journal of Chemical Engineering 2022年第2期35卷 389-398页

作者： Xu Hou Bochong Chen Zhenzhou Ma Jintao Zhang yuanhang Ning Donghe Zhang Liu Zhao Enxian Yuan Tingting Cui School of Chemical Engineering Changchun University of TechnologyChangchun 130012China Advanced Institute of Materials Science Changchun University of TechnologyChangchun 130012China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China Department of Chemistry Tsinghua UniversityBeijing 100084China

Due to the complexity of feedstock,it is challenging to build a general model for light olefins *** work was intended to simulate the formation of ethylene,propene and 1,3-butadiene in alkanes pyrolysis by referring the effects of normal/***,the pyrolysis of n-pentane,n-hexane,n-heptane,n-octane,n-nonane,n-decane,cyclohexane,methylcyclohexane,n-hexane and cyclohexane mixtures,and n-heptane and methylcyclohexane mixtures were carried out at 650–800℃,and a particular attention was paid to the measurement of ethylene,propene and 1,***,pseudo-first order kinetics was taken to characterize the pyrolysis process,and the effects of feedstock composition were *** was found that chain length and cyclo-alkane content can be qualitatively and quantitively represented by carbon atom number and pseudo-cyclohexane content,which made a significant difference on light olefins ***,the inverse proportional/quadratic function,linear function and exponential function were proposed to simulate the effects of chain length,cycloalkane content and reaction temperature on light olefins formation,*** the obtained empirical model well reproduced feedstock conversion,ethylene yield and propene yield in normal/cycloalkanes pyrolysis,it exhibited limitations in simulating 1,3-butadiene ***,the accuracy and flexibility of the present model was validated by predicting light olefins formation in the pyrolysis of multiple hydrocarbon *** prediction data well agreed with the experiment data for feedstock conversion,ethylene yield and propene yield,and overall characterized the changing trend of 1,3-butadiene yield along with reaction temperature,indicating that the present model could basically reflect light olefins production in the pyrolysis process even for complex feedstock.

关键词： Empirical model Normal-alkane Cyclo-alkane Pyrolysis Light olefins

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Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006–2011

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Journal of Environmental Sciences 2014年第1期26卷 23-36页

作者： Jinfeng Li Keding Lu Wei Lv Jun Li Liuju Zhong Yubo Ou Duohong Chen Xin Huang yuanhang Zhang College of Environmental Sciences Engineering Peking University Guangdong Provincial Environmental Monitoring Center

Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone （O3）, NO2 and total oxidant （Ox） were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbWyr was found for the annual averaged values from 2006 to 2011 in Guangdong, China. Such fast O3 increase is accompanied by a correspondingly fast NOx reduction as indicated by a fast NO2 reduction rate of 0,61 ppbV/yr. Based on a cluster analysis, the monitoring stations were classified into two major categories - rural stations （non-urban） and suburban/urban stations. The 03 concentrations at rural stations were relatively conserved while those at suburban/urban stations showed a fast increase rate of 2.0 ppbV/yr accompanied by a NO2 reduction rate of 1.2 ppbV/yr. Moreover, a rapid increase of the averaged O3 concentrations in springtime （13%/yr referred to 2006 level） was observed, which may result from the increase of solar duration, reduction of precipitation in Guangdong and transport from Eastern Central China. Application of smog production algorithm showed that the photochemical O3 production is mainly volatile organic compounds （VOC）-controlled. However, the photochemical O3 production is sensitive to both NOx and VOC for O3 pollution episode. Accordingly, it is expected that a combined NOx and VOC reduction will be helpful for the reduction of the O3 pollution episodes in Pearl River Delta while stringent VOC emission control is in general required for the regional O3 pollution control.

关键词： O3 cluster analysis temporal variation smog production algorithm Pearl River Delta

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Sustainable metal-free leather manufacture via synergistic effects of triazine derivative and vegetable tannins

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Collagen and Leather 2023年第2期5卷 119-131页

作者： yuanhang Xiao Jiajing Zhou Chunhua Wang Jinwei Zhang Vera D.Radnaeva Wei Lin Department of Biomass and Leather Engineering Key Laboratory of Leather Chemistry and Engineering of Ministry of EducationSichuan UniversityChengdu 610065China Department of NanoEngineering University of California San Diego9500 Gilman DriveLa JollaCA 92093USA Department of Leather and Fur Technology Water Resources and Commodity Research East Siberia State University of Technology and ManagementUlan-UdeBuryatiaRussia 670013 National Engineering Research Center of Clean Technology in Leather Industry Sichuan UniversityChengdu 610065China

Restrictions on heavy metals,especially chromium,have encouraged alternative tanning systems that can reduce environmental and human health risks from conventional chrome-based *** this work,metal-free combination tanning was developed by using vegetable tannins and a triazine-based syntan containing active chlorine groups(SACC).Specifically,the relationship between leather performance(e.g.,hydrothermal stability and organoleptic properties)and technical protocols(e.g.,types and dose of tannins)was systematically *** optimized protocol involving a unique procedure(i.e.,10%SACC pre-tanning,shaving,and 25%wattle tanning)endowed the leather with high shrinkage temperature(~92℃)and met the Chinese standards for shoe upper leather(QB/T 1873-2010).Our method not only produces zero chrome-containing solid wastes,but also uses~75%less tannin for leather *** excellent leather performance was ascribed to the synergistic effects,where SACC and wattle diffused into collagen fibrils and may bind to collagen via covalent,hydrogen and ionic bonding,locking the hierarchical structure of collagen from microfibrils to fiber ***,we summarized these findings and proposed a diffusion-binding-locking mechanism,providing new insights for current tanning *** with the biodegradable spent tanning liquor,this approach will underpin the development of sustainable leather manufacture.

关键词： Metal-free tanning Triazine derivative Vegetable tannins Synergistic effect Eco-friendly leather

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热处理对石墨烯镁基复合材料拉伸性能及微结构的影响

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广西科技大学学报 2024年第2期35卷 145-152页

作者：华振虎蓝永庭丁浩川解远航柯昌锐广西科技大学机械与汽车工程学院广西柳州545616

为研究时效对石墨烯纳米片/镁基复合材料(GNPs/AZ31)力学性能的影响,对GNPs/AZ31进行了300℃固溶1 h和200℃分别时效4、8、12、16、20、24 h的热处理,并开展不同时效时间下的GNPs/AZ31微观组织表征与拉伸力学性能试验研究。单轴拉伸力... 详细信息

为研究时效对石墨烯纳米片/镁基复合材料(GNPs/AZ31)力学性能的影响,对GNPs/AZ31进行了300℃固溶1 h和200℃分别时效4、8、12、16、20、24 h的热处理,并开展不同时效时间下的GNPs/AZ31微观组织表征与拉伸力学性能试验研究。单轴拉伸力学试验发现,随着时效时间的增加,GNPs/AZ31的力学性能呈现出先增加后减小的趋势,在时效时间为20 h时的综合力学性能最好,抗拉强度、屈服强度、延伸率、断裂功和显微硬度分别为381 MPa、258 MPa、23.7%、76 J/m^(3)和75.7 HV,比未处理的GNPs/AZ31复合材料分别提高了9.5%、4.5%、13.9%、24.6%和37.6%。微结构表征试验结果表明,随着时效时间的增加,GNPs/AZ31内第二相(Mg_(17)Al_(12))的析出数量明显增加,并且时效过程均以增加粒径小于1.0μm的小尺寸颗粒的连续析出为主;XRD图谱显示,随着时效时间的增加,Mg_(17)Al_(12)相衍射峰强度得到加强,GNPs/AZ31的(0002)基面织构强度得到提高。本研究可为改善GNPs/AZ31的综合力学性能提供重要的试验数据。

关键词： GNPs/AZ31 石墨烯时效析出相织构强度

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Chemical characterization of size-resolved aerosols in four seasons and hazy days in the megacity Beijing of China

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Journal of Environmental Sciences 2015年第6期27卷 155-167页

作者： Kang Sun Xingang Liu Jianwei Gu Yunpeng Li Yu Qu Junling An Jingli Wang yuanhang Zhang Min Hu Fang Zhang College of Environmental Sciences and Engineering Peking University State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences Institute for Urban Meteorology China Meteorological Administration College of Global Change and Earth System Science Beijing Normal University

Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m^3, respectively,throughout the measurement, with seasonal variation： nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM1.8/PM10 ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM（organic matter = 1.6 × OC（organic carbon）） and SIA（secondary inorganic aerosol） were major components of fine particles, while OM, SIA and Ca^2＋were major components in coarse particles. Moreover, secondary components, mainly SOA（secondary organic aerosol） and SIA,accounted for 46%-96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of（NH4）2SO4, NH4NO3, Ca SO4, Na2SO4 and K2SO4, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons.

关键词： Chemical components Size resolved aerosols Seasonal variation Haze day Beijing

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基于WHCNS模型的华北平原麦田灌溉制度优选研究

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河北水利电力学院学报 2024年第3期34卷 1-6,10页

作者：于晴王亚晖冯语周远航冯义祥中勘天成(北京)科技有限公司北京市海淀区100080 河北水利电力学院水利工程系河北省沧州市061001

华北地区的粮食生产在全国范围内地位突出,但是农业用水严重短缺;该研究以华北平原冬小麦为研究对象,首先利用华北地区2004年和2006年试验数据分析传统灌溉制度下水分运移规律及利用效率,结合WHCNS模型进行不同组合灌溉情景(研究设置总... 详细信息

华北地区的粮食生产在全国范围内地位突出,但是农业用水严重短缺;该研究以华北平原冬小麦为研究对象,首先利用华北地区2004年和2006年试验数据分析传统灌溉制度下水分运移规律及利用效率,结合WHCNS模型进行不同组合灌溉情景(研究设置总灌水量变化范围由100 mm至450 mm,提高灌水次数至5次)的模拟研究,使用综合指数法对灌溉量进行优选研究。最终得出350 mm为设定组合情境中的最佳灌溉量。

关键词： WHCNS模型冬小麦华北地区水分利用效率

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In situ monitoring of atmospheric nitrous acid based on multi-pumping flow system and liquid waveguide capillary cell

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Journal of Environmental Sciences 2016年第5期28卷 273-284页

作者： Yuhan Liu Keding Lu Huabin Dong Xin Li Peng Cheng Qi Zou Yusheng Wu Xingang Liu yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University Institute of Energy and Climate Research: Troposphere (IEK-8) Forschungszentrum Juelich GmbH State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University

In the last four decades, various techniques including spectroscopic, wet chemical and mass spectrometric methods, have been developed and applied for the detection of ambient nitrous acid（HONO）. We developed a HONO detection system based on long path photometry which consists of three independent modules i.e., sampling module, fluid propulsion module and detection module. In the propulsion module, solenoid pumps are applied. With solenoid pumps the pulsed flow can be computer controlled both in terms of pump stroke volume and pulse frequency, which enables the attainment of a very stable flow rate. In the detection module, a customized Liquid Waveguide Capillary Cell（LWCC） is used. The customized LWCC pre-sets the optical fiber in-coupling with the liquid wave guide, providing the option of fast startup and easy maintenance of the absorption photometry. In summer 2014, our system was deployed in a comprehensive campaign at a rural site in the North China Plain. More than one month of high quality HONO data spanning from the limit of detection to 5 ppb were collected. Intercomparison of our system with another established system from Forschungszentrum Juelich is presented and discussed. In conclusion, our instrument achieved a detection limit of 10 ppt V within2 min and a measurement uncertainty of 7%, which is well suited for investigation of the HONO budget from urban to rural conditions in China.

关键词： HONO Photometry Field campaign Atmospheric chemistry

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基于PCA与PSO-SVM的谐振接地系统故障选线方法

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电瓷避雷器 2024年第1期 86-92页

作者：聂远航刘晓波陈再航孙宗宇包宁宁贵州大学电气工程学院贵阳550000

为解决谐振接地系统单相接地故障对故障初始角为零以及接地电阻为高阻的故障线路识别效果差的问题,提出一种基于主成分分析与粒子群算法优化支持向量机(PCA-PSO-SVM)的选线方法。该方法通过Matlab/Simulink对小电流接地系统进行仿真,采... 详细信息

为解决谐振接地系统单相接地故障对故障初始角为零以及接地电阻为高阻的故障线路识别效果差的问题,提出一种基于主成分分析与粒子群算法优化支持向量机(PCA-PSO-SVM)的选线方法。该方法通过Matlab/Simulink对小电流接地系统进行仿真,采集瞬时零序功率数据,将数据输入PCA-PSO-SVM模型中进行训练与测试,并将测试结果与单一的支持向量机模型以及经粒子群优化后的支持向量机模型进行对比,结果表明PCA-PSO-SVM模型有着更好的选线准确度与选线效率。

关键词：故障选线瞬时零序功率主成分分析粒子群算法支持向量机

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Insights into the phenomenon of an explosive growth and sharp decline in haze:A case study in Beijing

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Journal of Environmental Sciences 2019年第10期31卷 122-132页

作者： Wenguang Li Xingang Liu yuanhang Zhang Qinwen Tan Miao Feng Mengdi Song Lirong Hui Yu Qu Junling An Haokai Gao State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China State Key Joint Laboratory of Environment Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China Chengdu Academy of Environmental Sciences Chengdu 610072 China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Environmental monitoring station of Tianjin Port Free Trade Zone Tianjin 300308 China

A severe haze episode occurred in winter in the North China Plain(NCP),and the phenomenon of an explosive growth and sharp decline in PM2.5(particulate matter with an aerodynamic diameter equal to or less than 2.5μm)concentration was *** study the systematic causes for this phenomenon,comprehensive observations were conducted in Beijing from November 26 to December 2,2015;during this period,meteorological parameters,LIDAR data,and the chemical compositions of aerosols were *** haze episode was characterized by rapidly varying PM2.5 concentration,and the highest PM2.5 concentration reached 667μg/*** the haze episode,the NCP was dominated by a weak high-pressure system and continuously low PBL(planetary boundary layer)heights,which are unfavorable conditions for the diffusion of *** large increases in the concentrations of SNA(SO42-,NO3-and NH4+)during the haze implied that the formation of SNA was the largest *** vapor also played a vital role in the formation of haze by promoting the chemical transformation of secondary pollutants,which led to higher PM2.5 *** spatial distributions of PM2.5 in Beijing at different times and the backward trajectories of the air masses also indicated that pollutants from surrounding provinces in particular,contributed to the higher PM2.5concentration.

关键词： Haze episodes Explosive growth Sharp decline Beijing

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Exploring atmospheric free-radical chemistry in China:the self-cleansing capacity and the formation of secondary air pollution

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National Science Review 2019年第3期6卷 579-594页

作者： Keding Lu Song Guo Zhaofeng Tan Haichao Wang Dongjie Shang Yuhan Liu Xin Li Zhijun Wu Min Hu yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University CAS Center for Excellence in Regional Atmospheric Environment Chinese Academy of Sciences

Since 1971, it has been known that the atmospheric free radicals play a pivotal role in maintaining the oxidizing power of the troposphere. The existence of the oxidizing power is an important feature of the troposphere to remove primary air pollutants emitted from human beings as well as those from the biosphere. Nevertheless, serious secondary air-pollution incidents can take place due to fast oxidation of the primary pollutants. Elucidating the atmospheric free-radical chemistry is a demanding task in the field of atmospheric chemistry worldwide, which includes two kinds of work: first, the setup of reliable radical detection systems; second, integrated field studies that enable closure studies on the sources and sinks of targeted radicals such as OH and NO. In this review, we try to review the Chinese efforts to explore the atmospheric free-radical chemistry in such chemical complex environments and the possible link of this fast gas-phase oxidation with the fast formation of secondary air pollution in the city-cluster areas in China.

关键词： atmospheric chemistry free radicals new particle formations OH NO3

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