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Ammonia has been identified as a promising sustainable fuel and hydrogen source for solid oxide fuel cells (SOFC). This paper aims to provide a literature review on ammonia‐fed SOFCs. Both experimental studies and mathematical modeling investigations on NH3‐fed SOFC are included and discussed. It is found that NH3 is a technically feasible fuel for direct use in SOFCs and the performance of NH3‐fed SOFC is comparable with that of the H2 fed SOFC. Experimental study in literature also demonstrates that both oxygen ion‐conducting electrolyte (SOFC‐O) and proton‐conducting electrolyte (SOFC‐H) can be used in NH3‐fed SOFC, as the amount of NOx generated in a SOFC‐O is negligible. Fabricating thin film electrolyte and developing more reactive electrode materials are important to improve the performance of NH3‐fed SOFCs. Mathematical models are useful design tools for understanding the coupled transport and reaction phenomena and for optimizing the SOFC performance. Thermodynamic and pioneering 1D electrochemical models have been developed, validated and demonstrated to be reliable by the present author. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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提出了一种新型的太阳能加热熔融盐化学循环反应体系,整个过程分两步:第一步,利用熔融碱金属碳酸盐吸收、储备、传输太阳能,在熔融盐介质中CH4与金属氧化物MxOy反应生成相应的金属和合成气;第二步,金属分解水产生氢气和相应MxOy,从而MxOy又循环到第一步再利用.根据最小吉布斯自由能原理,采用化学热力学计算软件HSC Chemistry 5.1,对CH4与几种MxOy气-固相反应的△G°进行了计算和分析,进一步分析了在熔融碱金属碳酸盐(摩尔比为1:1的Na2CO3和K2CO3)体系中温度对反应产物平衡组分的影响.结果表明,理论上只有ZnO和SnO2适合该反应体系,其反应气体产物中合成气的量随反应温度的增加而增加,比较适宜的反应温度在1200K左右.计算结果表明100MW的太阳能能量系统至少可以提供每秒生产5.32kg液态金属Zn所需能量,实现每秒将3.6×104kJ的太阳能转化为化学能. 相似文献
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文章选取Nafion 211和Nafion 117膜作为电化学压缩隔膜,通过仿真建模方法研究了隔膜特性对电化学压缩机压缩性能的影响。研究结果表明:隔膜欧姆阻抗对电压效率影响显著,隔膜气密性对电流效率影响显著;与Nafion 117膜相比,将Nafion 211膜应用于电化学压缩机时,电化学压缩机能够获得更高的能量效率,当工作电流为0.5 A/cm^2,压缩比为3时,等温压缩效率最高可达到50%。将以Nafion 211膜为隔膜,工作电流为2 A/cm^2的电化学压缩机用于制氢厂的管束车充装,当气源压力为2 MPa,管束车压力由5 MPa充装至20 MPa时,平均能量效率为35%,综合平均电耗为2 kW·h/kg,比目前常用的机械往复式压缩机的电耗降低了30%以上。 相似文献
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多元混合熔融盐的制备及其性能研究 总被引：1，自引：0，他引：1
采用静态高温混合熔融法制备以硝酸钾、亚硝酸钠、硝酸钠为三元基元和添加剂构成多元混合熔盐.通过热稳定性、放热实验以及X-射线衍射(XRD)相分析和DSC热分析等表征技术,确定在三元熔盐中加入5%添加剂additive A时,多元混合熔盐比三元熔盐的高温热稳定性好.在不提高熔盐固体析出温度的前提下,可以使其最佳操作温度由原来400～500℃提高到约550℃.从多元混合熔盐中NO_2~-含量变化和相变潜热损失方面可以发现添加剂adttive A的加入可以降低多元熔盐劣化程度,提高混合熔盐的蓄热效率. 相似文献
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熔盐炉经常用于400℃以上的介质换热,熔盐炉出炉烟气温度较高,应用余热回收系统回收能量可取得显著的节能效果。本文针对余热回收系统形式及热力参数,分析各种余热回收系统的优缺点,为熔炉盐炉余热回收系统设计提供理论依据。 相似文献
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A cavity structure effectively decreases the heat loss of a receiver. This paper applies the widely used collector analysis method to derive the total heat loss coefficient and efficiency factor for a cavity receiver. Based on the derived factors, this paper investigates the effect of different parameters, such as absorber surface temperature and emissivity, on thermal performance. The absorber surface emissivity significantly affects the total heat loss coefficient at high temperatures. The effect of the absorber surface temperature on the total heat loss coefficient is significant, while the effect of the ambient temperature on the total heat loss coefficient can be ignored. The present results can help to determine the testing conditions for the cavity receiver by using molten salt as the heat transfer fluid. 相似文献
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将622型前驱体与0.24 Li2CO3-0.76 LiOH锂盐体系、氯化钾熔盐混合,在通空气气氛中采用熔盐法制备了622型三元电池正极材料（LNCM）,采用XRD和SEM表征考察了锂源和钾盐的比例及焙烧温度和时间对LNCM晶体结构的影响,得出最佳制备条件为：锂源与钾盐1：5,前驱体和锂源1：1.1,焙烧温度为750℃,焙烧时间为15 h。将LNCM作为正极材料组装成扣式电池,对其进行了多项电化学性能指标测试,结果表明该材料在2.7~4.3 V内,0.1 C放电倍率下,具有182.5 mA·h/g首次放电容量,库仑效率为89.1%;在2.7~4.5 V,0.1 C条件下循环100圈后容量仍有183.2 mA·h/g,容量保持率为91.5%。 相似文献
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Yasuo Takagi Mitsuru Onoda Tamotsu Toriyama Katsunori Kawasaki Toshiyuki Hattori 《亚洲传热研究》2013,42(5):444-458
This study investigated the characteristics of cell performance degradation, decline of component performance, and changes in the properties of membrane electrode assembly materials caused by repeated cold starts under a subzero condition of ?30 °C. It was made clear that functional decay appeared mainly at the cathode due to increased proton conductive impedance and reduction of reactivity of the electrode catalyst. Among the cathode components, an increase in proton conductive impedance in the cathode electrolyte was dominant. Furthermore, the application of ion chromatography and a newly developed proton‐induced gamma‐ray emission method to measure fluorine in the off‐gas drain revealed that decomposition of the electrolyte was dominant in the cathode catalyst layer. A decrease in fluorine in the cathode electrolyte measured by fluorine‐19 nuclear magnetic resonance confirmed this decomposition. A hypothesis is also presented concerning the cause of the performance degradation. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20394 相似文献
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Based on a 1D electrochemical model, a series of galvanostatic charge processes of lithium ion batteries with different initial electrolyte salt concentrations are simulated and investigated. In light of the simulation results, it is found that many electrochemical characters, including charge curve, end‐of‐charge salt concentration, anode potential, and reaction depth distribution, can all be affected by initial electrolyte salt concentration. Meanwhile, the lithium plating phenomenon commonly occurring during charge is studied with batteries of different salt concentrations during overcharge. A corresponding solution, changing the thickness ratio of anode to cathode, is proposed, which can also be used to extend the charging capacity. Overall, this study gives better understanding of the relevance between electrochemical behaviors of charging battery and initial electrolyte salt concentration, thus emphasizes the important role of electrolyte salt concentration in the performance and health of lithium ion battery. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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An electrochemical analysis is carried out from a kinetic electrochemistry perspective of a CuCl/HCl electrolysis cell, within the CuCl thermochemical water splitting process for hydrogen production. The anolyte is a solution of 2 mol L?1 CuCl(aq) and 10 mol L?1 HCl(aq) while the catholyte solution is 11 mol L?1 HCl(aq) . The cell current density of 0.5 A cm?2 and voltage of 0.7 V are the desired working conditions for a CuCl/HCl electrolyzer. The current density of 0.5 A cm?2 is assumed to occur at a 5% anolyte conversion degree. At 25°C , the activation overpotential of the anode half‐reaction is found to be 53 mV for a current density of 0.5 A cm?2 while the activation overpotential of the cathode half‐reaction for the same condition is 87 mV. An increase in working temperature decreases the overpotential of the anode half‐reaction and increases the cathode half‐reaction activation overpotential. The ohmic overpotential of the cell membrane is almost 1000 times smaller than that of the activation overpotentials of the electrode half‐reactions for the same temperature and current density. A higher working temperature results in a lower membrane ohmic overpotential. The required voltage to trigger electrolysis for a current density of 0.5 A cm?2 is found to be 0.53 V at 25°C and 0.59 V at 80°C and a higher temperature results in a higher electrochemical efficiency. The cell electrochemical efficiency increases linearly with working temperature while the voltage efficiency peaks at 75% at 60°C . 相似文献
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Since the triple bond in a nitrogen molecule is considered to be one of the strongest bond to break, the ammonia synthesis under atmospheric pressure and mild temperature becomes a remarkably challenging problem. In the present research study, a novel method is introduced for electrochemical ammonia synthesis through integrating the reactor with the electromagnetic zero-voltage switching (ZVS) device. The reactor is tested under an induced electromagnetic (EM) field in galvanostatic mode by varying the operating parameters that include temperature, flow rate, and current density. The experimental setup is designed and operated toward performing the electrochemical synthesis. The maximum Faradaic efficiency achieved with EM field is 4.5%, and the ammonia formation rate is found to be 1.21 × 10−10 mol cm−2 s−1 at an applied constant current of 6.4 mA cm−2 and EM field of 49 mT. Furthermore, the experiments are extended to include the ammonia synthesis with and without EM field influence on the reaction; in which case, the reduction potential becomes 1.25 V with the presence of EM field, while it is 1.7 V without EM field when the applied current of 6.4 mA cm−2 is incorporated. This study demonstrates that the electrochemical ammonia synthesis, via nitrogen reduction, can be achieved spontaneously, which is beyond the classical approach for electrochemical ammonia synthesis. 相似文献
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Sonal Sahai Ashi Ikram Snigdha Rai Rohit Shrivastav Sahab Dass Vibha R. Satsangi 《国际能源研究杂志》2016,40(13):1811-1819
A visible light active and stable photoelectrode has been developed by depositing a passivating layer of ZnS QDs on CdS QDs sensitized hematite photoelectrode (Hematite‐CdS/ZnS) for PEC generation of hydrogen. Photoelectrochemical properties, in terms of stability and efficiency, have been investigated on the various hematite photoelectrodes sensitized with CdS QDs and CdS/ZnS QDs by varying number of SILAR cycles. I–V characteristics show that two layers of ZnS QDs deposited over three layers of CdS could enhance PEC response of hematite and efficiency by a factor of 3 and 11 respectively. Chronoamperometry measurement ensures that after adding a layer of ZnS QDs, CdS sensitized hematite film turns out to be a stable photoelectrode in the electrolyte. Prepared photoelectrodes have been characterized by XRD, SEM, HRTEM and UV–Vis spectrophotometer for various structural, morphological and optical properties to analyze PEC results. Mott–Schottky analysis and incident photon to current conversion efficiency (IPCE) measurements of sensitized hematite photoelectrode supported the improved PEC response of CdS/ZnS QDs sensitized hematite thin films. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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In the current study, a solar tower–based energy system integrated with a thermal energy storage option is offered to supply both the electricity and freshwater through distillation and reverse osmosis technologies. A high‐temperature thermal energy storage subsystem using molten salt is considered for the effective and efficient operation of the integrated system. The molten salt is heated up to 565°C through passing the solar tower. The thermal energy storage tanks are designed to store heat up to 12 hours. The temperature variations in the storage tanks are studied and compared accordingly for evaluation. The effect of operating temperatures on the freshwater production and overall system efficiency is determined. About 24.46 MW electricity is generated in the steam turbine under sunny conditions. Furthermore, the storage subsystem stores heat during sunny hours to utilize later in cloudy hours and night time. The produced power decreases to 20.17 MW in discharging hours due to temperature decrease in the tank. The electricity generated by the system is then used to produce freshwater through the reverse osmosis units and also to supply electricity for the residential use. A total flowrate of 240.02 kg/s freshwater is obtained by distillation and reverse osmosis subsystems. 相似文献
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将电磁感应加热技术应用到低谷电加热熔盐储热供暖领域,搭建熔盐电磁感应加热实验系统,以感应加热器为研究对象,探究熔盐以及线圈冷却水在不同熔盐流速和线圈电流工况下的温度变化规律,计算加热效率和冷却水热损失率。结果表明：电磁感应加热器可以快速加热熔盐,熔盐温升主要集中在开始加热80～240 s之间,温升速率在100 s时最大;改变线圈电流或熔盐流速,可以产生不同终温的熔盐,流速0.177 m/s时,熔盐在不同电流下出口温度分别为201.452 ℃、203.891 ℃、207.599 ℃、212.975 ℃和221.454 ℃;熔盐流速一定,熔盐和线圈冷却水吸热量随线圈电流的增加而升高;线圈电流不变,熔盐吸热量随流速的增加而升高、线圈冷却水吸热量随流速增加而降低;熔盐流速0.296 m/s、线圈电流600 A时,熔盐加热效率为69.28%,线圈冷却水热损失率为16.45%。 相似文献
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为了进一步降低燃煤发电机组在最低锅炉稳燃负荷下的电负荷率,采用Ebsilon软件建立了集成烟气及主蒸汽多热源熔盐储热的燃煤发电系统模型,并结合660MW超临界机组的案例对集成系统的热力学性能进行分析。计算结果表明：在储热过程中,主蒸汽最大分流流量为88.40 kg/s,燃煤机组的最低电负荷率可由30%降低至11.75%;而在释热过程中,燃煤发电系统的输出功率增加了88.50 MW,占额定负荷的13.40%;在30%THA储热并在75%THA释热时,集成系统的最高等效循环效率为85.89%。此外,还分析了集成系统在不同释热基准工况下的系统性能：在储热过程的附加?损为负,而在放热过程附加?损为正;集成系统在100% THA工况下放热的附加?损最大,最大附加?损为41.96 MW,而集成系统在50% THA工况下放热的附加?损最小,其最大附加?损为12.40 MW。总体而言,集成系统在30% THA储热并且在50% THA工况下释热时系统性能最好,系统等效循环效率最高可达94.35%。 相似文献
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Shaolong Li Jianxun Song Yusi Che Shuqiang Jiao Jilin He Bin Yang 《ENERGY & ENVIRONMENTAL MATERIALS》2023,6(2):e12339
The properties of non-oxide materials are continuously revealed, and their applications in the fields of ceramics, energy, and catalysis are increasingly extensive. Regardless of the traditional binary materials or the MAX phases, the preparation methods, which are environmentally friendly, efficient, economical, and easy to scale-up, have always been the focus of attention. Molten salt synthesis has demonstrated unparalleled advantages in achieving non-oxide materials. In addition, with the development of the process in molten salt synthesis, it also shows great potential in scale-up production. In this review, the recent progress of molten salt synthesis in the preparation of binary non-oxide and MAX phase is reviewed, as well as some novel processes. The reaction mechanisms and the influence of synthetic conditions for certain materials are discussed in detail. The paper is finalized with the discussion of the application prospect and future research trends of molten salt synthesis in non-oxide materials. 相似文献