检索结果-南通市图书馆

CFD Simulation of a Hydrogen/Argon Plasma Jet Reactor for coal pyrolysis

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2004年第4期20卷 446-451页

作者： CHEN H. G. XIE K. C. Taiyuan University of Technology Taiyuan University of Technology Taiyuan 030024 P. R. China City University London EC1V 0HB UKand Taiyuan 030024 P. R. China

A Computational Fluid Dynamics(CFD) model was formulated for DC arc hydrogen/argon plasma jet reactors used in the process of the thermal H_2/Ar plasma pyrolysis of coal to acetylene. In this model, fluid flow, convective heat transfer and conjugate heat conductivity are considered simultaneously. The error caused by estimating the inner-wall temperature of a reactor is avoided. The thermodynamic and transport properties of the hydrogen/argon mixture plasma system, which are usually expressed by a set of discrete data, are fitted into expressions that can be easily implemented in the program. The effects of the turbulence are modeled by two standard k-εequations. The temperature field and velocity field in the plasma jet reactor were calculated by employing SIMPLEST algorithm. The knowledge and insight obtained are useful for the design improvement and scale-up of plasma reactors.

关键词： Plasma Reactor Computational fluid dynamics coal pyrolysis

Investigation of kinetic and thermodynamic parameters of coal pyrolysis with model-free fitting methods

在线全文

学校读者我要写书评

暂无评论

Carbon Resources Conversion 2020年第1期3卷 173-181页

作者： Jingchong Yan Qitong Yang Li Zhang Zhiping Lei Zhanku Li Zhicai Wang Shibiao Ren Shigang Kang Hengfu Shui School of Chemistry&Chemical Engineering Anhui Province Key Laboratory of Coal Clean Conversion and High Valued UtilizationAnhui University of TechnologyMaanshan 243002Anhui ProvincePR China School of Computer Science and Technology Anhui University of TechnologyMaanshan 243002Anhui ProvincePR China

Kinetic analyses are important means for understanding the complicated coal pyrolysis *** work conducted non-isothermal pyrolysis of four low-medium rank coals with thermogravimetric analyzer at different heating rates(5,10 and 20 K/min).Four model-free fitting approaches including KAS,OFW,Starink and Friedman methods were used to analyze pyrolysis kinetics of the *** parameters including enthalpy(ΔH)Gibbs free energy(ΔG)and entropy(ΔS)were calculated with the activation values(E)obtained with KAS *** the kinetic analysis,the KAS,OFW and Starink methods give close E values over the whole conversion range,but the Friedman method shows more deviant *** thermodynamic favorability of coal pyrolysis is discussed,bothΔH andΔG increase with conversion consistently with the variation of E,revealing that pyrolysis is endothermic and thermodynamic favorability is reduced with conversion *** minusΔS implies that coal structures evolve from disordered to organized ones as universally *** results are expected to deepen our understanding and to optimize the conditions of coal pyrolysis.

关键词： coal pyrolysis Kinetic analysis Model-free fitting Thermodynamic parameters

Isolated 4-20 mA Current-Loop System in the Experiment of coal pyrolysis in H-plasma Producing Acetylene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2009年第5期26卷 519-521页

作者：沈洁罗家融陈龙威孟月东舒兴胜方世东 Institute of Plasma Physics Chinese Academy of Sciences College of Science Donghua University

The purpose of this paper is to demonstrate a systematic approach to design high performance signal conditioning circuits,and to show how to implement the 4-20 mA analog current-loop transmitter and receiver circuits by using isolation *** basic principle and typical applicable circuits of the 4-20 mA current loop isolation chip T1100N,the current-limiting circuit and filter circuit are *** the experimental testing data of the circuits are analyzed.

关键词： signal isolation coal pyrolysis plasma torch

Study on Transition Metal Catalysts for Hydrogen Production from coal pyrolysis

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第4期19卷 372-376页

作者： ZHANG Lei SHU Xinqian ZHANG Lei ZHANG Lixin LOU Keqi School of Chemical and Environment Engineering China University of Mining and Technology (Beijing) Beijing100083 China College of Geology and Environment Xi'an University of Science and Technology Xi'an 710054 China Protection and Energy -Saving Equipment Research Institute China National Heavy Machinery Research InstituteCo. Ltd. Xi'an 710032China

In this paper,13 kinds of transition metals are studied as catalysts for the hydrogen production from coal pyrolysis, and relationships between the catalytic activity of a transition metal and its outer electron configuration,d% of transition metals and geometric configuration are *** results show that the same group of transition metals show good similarity for hydrogen production from coal pyrolysis;the d%of transition metals which have activity for hydrogen production from coal pyrolysis is between 40%-50%;all transition metals which have catalytic activity possess either a face-centered cubic or a hexagonal crystal ***,it is important to choose a transition metal with an appropriate d%and crystal structure as the catalyst for hydrogen production from coal pyrolysis.

关键词： transition metal coal pyrolysis hydrogen production

Experiments and Modelling of coal pyrolysis underFluidized Bed Conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1999年第3期8卷 202-206页

作者： ZhangYongzhe XuXiangdong 等 DepartmentofThermalEngineering TsinghuaUniversityBeijing100084China DepartmentofThermalEngineering

The pyrolysis behavior of two Chinese coals has been investigated in a laboratory-scale bubbling fluidized bed system in Siegen University, Germany. Experimental equipment and procedure are introduced. The amounts of pyrolysis species of each coal were measured, calculated and compared. A newmethod was presented to determine the needed parameters in FG-DVC model with the experimentalresults instead of other much more complicated experiments.

关键词： coal pyrolysis fluidized bed modelling.

A density functional theory study on the decomposition of aliphatic hydrocarbons and cycloalkanes during coal pyrolysis in hydrogen plasma

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2015年第1期24卷 65-71页

作者： Xiaoyuan Huang Dangguo Cheng Fengqiu Chen Xiaoli Zhan Key Laboratory of Biomass Chemical Engineering of Ministry of Education Zhejiang University Department of Chemical and Biological Engineering Zhejiang University

To get deep understanding of the reaction mechanism of coal pyrolysis in hydrogen plasma, the decomposition reaction pathways of aliphatic hydrocarbons and cycloalkanes, which are two main components in volatiles from coal, were investigated. Methane and cyclohexane were chosen as the model compounds. Density functional theory was employed, and many reaction pathways were involved. Calculations were carried out in Gaussian 09 at the B3LYP/6-31G（d,p） level of the theory. The results indicate that the main pyrolysis products of methane and cyclohexane in hydrogen plasma are both hydrogen and acetylene, and the participation of active hydrogen atoms makes dehydrogenation reactions more favorable. H2 mainly comes from dehydrogenation process, while many reaction pathways are responsible for acetylene formation. During coal pyrolysis in hydrogen plasma, three main components in volatiles like aliphatic hydrocarbons, cycloalkanes and aromatic hydrocarbons lead to the formation of hydrogen and acetylene, but their contributions to products distribution are different.

关键词： coal pyrolysis thermal plasma density functional theory aliphatic hydrocarbons cycloalkanes

Tar formation characteristic of integrated process of coal pyrolysis with dry reforming of low carbon alkane over Ni/La_(2)O_(3)-ZrO_(2)

在线全文

学校读者我要写书评

暂无评论

燃料化学学报（中英文） 2024年第12期52卷 1823-1833,I0001-I0006页

作者： LÜJiannan LI Yang JIN Lijun HU Haoquan State Key Laboratory of Fine Chemistry Institute of Coal Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China

coal pyrolysis integrated with dry reforming of low-carbon alkane(CP-DRA)is an effective way to improve tar ***/La_(2)O_(3)-ZrO_(2) with a La/Zr ratio of 4 was a good catalyst for DRA to inhibit carbon deposition and obtain high tar yield in *** this study,the fraction distribution and component of tars from CP-DRA and coal pyrolysis in N_(2) atmosphere(CP-N_(2))were characterized by using several methods to understand the effect of DRA on coal *** isotope trace method was also used to discuss the role of low-carbon alkane in *** results showed that the tar from CP-N_(2)is mainly composed of aliphatic compounds with more C_(al),H_(al) and CH+CH_(2),and the tar from CP-DRA contains more Car,Har,and CH_(3),and has lower weight-average molecular weight and more light tar content than CP-N_(2).A small amount of C_(2)H_(6) addition in CP-DRA will raise the ratio of H_(β) and CH+CH_(2).Electron paramagnetic resonance(EPR)analysis shows that the tar from CP-DRA has a higher radical concentration while the corresponding char has a lower radical *** isotope trace experiment showed that alkanes provide·H,·CH_(3),*** stabilize the radicals from coal pyrolysis and result in more alkyl aromatic compounds during CP-DRA.

关键词： coal pyrolysis dry reforming low carbon alkane Ni/La_(2)O_(3)-ZrO_(2) tar

Enhanced near-zero-CO2-emission chemicals-oriented oil production from coal with inherent CO2 recycling: Part I—PRB coal fast pyrolysis coupled with CO2/CH4 reforming

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of coal Science & Technology 2020年第3期7卷 433-443页

作者： Xingjun Wang Bin Wei Xin Huang Maohong Fan Yonggang Wang Xueli Chen School of Resources and Environment Engineering East China University of Science and TechnologyShanghai200237China School of Chemical and Environmental Engineering China University of Mining and TechnologyBeijing100080China Departments of Petroleum and Chemical Engineering University of WyomingLaramieWY82071USA School of Energy Resources University of WyomingLaramieWY82071USA

In this study,the Powder River Basin(PRB)coal fast pyrolysis was conducted at 700°C in the atmosphere of syngas produced by CH4-CO2 reforming in two different patterns,including the double reactors pattern(the first reactor is for syngas production and the second is for coal pyrolysis)and double layers pattern(catalyst was at upper layer and coal was at lower layer).Besides,pure gases atmosphere including N2,H2,CO,H2-CO were also tested to investigate the mechanism of the coal pyrolysis under different *** pyrolysis products including gas,liquid and char were characterized,the result showed that,compared with the inert atmosphere,the tar yield is improved with the reducing atmospheres,as well as the tar *** hydrogen partial pressure is the key point for that *** the atmosphere of H2,the tar yield was increased by 31.3%and the contained BTX(benzene,toluene and xylene)and naphthalene were increased by 27.1%and 133.4%.The double reactors pattern also performed outstandingly,with 25.4%increment of tar yield and 25.0%and 79.4%for the BTX and *** double layers pattern is not effective enough due to the low temperature(700°C)in which the Ni-based catalyst was not fully activated.

关键词： coal pyrolysis coal tar CO2/CH4 reforming BTX

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of coal Science & Technology 2023年第2期10卷 181-195页

作者： Lin Qian Jinkai Xue Chao Tao Chao Ma Xiaopeng Jiang Feiqiang Guo School of Low-Carbon Energy and Power Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Clean Energy Utilization Zhejiang University310027 HangzhouChina

The critical issue in developing mature Oxy-coal Combustion Steam System technology could be the reactivity of deminer-alized coal which,is closely related to its chemical *** chemical structures of Liupanshui raw coal(LPS-R)and Liupanshui demineralized coal(LPS-D)were analyzed by FTIR and solid-state *** pyrolysis experiments were carried out by TG,and the pyrolysis kinetics was analyzed by three iso-conversional *** and 13C-NMR results suggested that the carbon structure of LPS coal was not altered greatly,while demineralization promoted the maturity of coal and the condensation degree of the aromatic ring,making the chemical structure of coal more *** oxygen-containing functional groups with low bond energy were reduced,and the ratio of aromatic carbon with high bond energy was increased,decreasing the pyrolysis *** curve-fitting results revealed that the thermal weight loss of LPS coal mainly came from the cleavage of aliphatic covalent *** pyrolysis kinetics analysis of LPS-R and LPS-D,the apparent activation energies were 76±4 to 463±5 kJ/mol and 84±2 to 758±12 kJ/mol,respectively,under different conversion *** reactivity of the demineralized coal was inhibited to some extent,as the apparent activation energy of pyrolysis for LPS-D increased by acid treatment.

关键词： Demineralization Chemical structure of coal coal pyrolysis pyrolysis kinetics Iso-conversional