1,4-Hydroquinone is a Hydrogen Reservoir for Fuel Cells and Recyclable via Photocatalytic Water Splitting

Photocatalytic splitting of water was carried out in a two-phase system. Nanocrystalline titanium dioxide was used as photocatalyst and potassium hexacyanoferrate(III)/(II) as electron transporter. Generated hydrogen was chemically stored by use of a 1,4-benzoquinone/1,4-hydroquinone system, which was used as a recyclable fuel in a commercialised direct methanol fuel cell (DMFC). The electrical output of the cell was about half compared to methanol. The conversion process for water splitting and recombination in a fuel cell was monitored by UV-Vis spectroscopy and compared to a simulated spectrum. Products of side reactions, which lead to a decrease of the overall efficiency, were identified based on UV-Vis investigations. A proof of principle for the use of quinoide systems as a recyclable hydrogen storage system in a photocatalytic water splitting and fuel cell cyclic process was given.

Modeling of Large-Scale Hydrogen Storage System Considering Capacity Attenuation and Analysis of Its Efficiency Characteristics

In the existing power system with a large-scale hydrogen storage system,there are problems such as low efficiency of electric-hydrogen-electricity conversion and single modeling of the hydrogen storage system.In order to improve the hydrogen utilization rate of hydrogen storage system in the process of participating in the power grid operation,and speed up the process of electric-hydrogen-electricity conversion.This article provides a detailed introduction to the mathematical and electrical models of various components of the hydrogen storage unit,and also establishes a charging and discharging efficiency model that considers the temperature and internal gas partial pressure of the hydrogen storage unit.These models are of great significance for studying and optimizing gas storage technology.Through these models,the performance of gas storage units can be better understood and improved.These studies are very helpful for improving energy storage efficiency and sustainable development.The factors affecting the charge-discharge efficiency of hydrogen storage units are analyzed.By integrating the models of each unit and considering the capacity degradation of the hydrogen storage system,we can construct an efficiency model for a large hydrogen storage system and power conversion system.In addition,the simulation models of the hydrogen production system and hydrogen consumption system were established in MATLAB/Simulink.The accuracy and effectiveness of the simulation model were proved by comparing the output voltage variation curve of the simulation with the polarization curve of the typical hydrogen production system and hydrogen consumption system.The results show that the charge-discharge efficiency of the hydrogen storage unit increases with the increase of operating temperature,and H2 and O2 partial voltage have little influence on the charge-discharge efficiency.In the process of power conversion system converter rectification operation,its efficiency decreases with the increase of temperature,while in the process of inverter operation,power conversion system efficiency increases with the increase of temperature.Combined with the efficiency of each hydrogen storage unit and power conversion system converter,the upper limit of the capacity loss of different hydrogen storage units was set.The optimal charge-discharge efficiency of the hydrogen storage system was obtained by using the Cplex solver at 36.46%and 66.34%.

AB_5-type Hydrogen Storage Alloy Modified with Ti/Zr Used as Anodic Materials in Borohydride Fuel Cell

Fuel cell using borohydride as the fuel has received much attention. AB5-type hydrogen storage alloy used as the anodic material instead of noble metals has been investigated. In order to restrain the generation of hydrogen and enhance the utilization of borohydride, Ti/Zr metal powders has been added into the parent LmNi4.78Mn0.22 （where Lm is La-richened mischmetal） alloy （LNM） by ball milling and heat treatment methods. It is found that the addition of Ti/Zr metal powders lowers the electrochemical catalytic activity of the electrodes, at the same time, restrains the generation of hydrogen and enhances the utilization of the fuel. All the results show that the hydrogen generation rate or the utilization of the fuel is directly relative to the electrochemical catalytic activity or the discharge capability of the electrodes. The utilization of the fuel increases with discharge current density. It is very important to find a balance between the discharge capability and the utilization of the fuel.

Modeling and Simulation of Hydrogen Storage Device for Fuel Cell Plant

The article reviews a brief literature on the modeling of hydrogen storage device for fuel cell. Different dimensional approaches in modeling hydrogen absorption/desorption in a metal hydride reactor for use in fuel cell are summarized. Mathematical modeling equations involved are also stated. The effect of various operating parameters such as temperature, concentration, viscosity, thermal conductivity and time on the gas is also verified. The importance of various simulation software with reference to their major functions is also identified. The review concludes on the opportunities and challenges with the use of hydrogen as an alternative renewable energy.

Electrochemical properties of AB_5 type hydrogen storage alloy as anode electrocatalyst of PEMFC

The electrocatalytic properties of hydrogen storage alloy（HSA） MlNi3.65Co0.85Al0.3Mn0.3 substituting Pt as anode electrocatalyst of PEMFC was investigated. It is found that, after being optimized, the electrocatalytic abilities of the HSA is reasonably good, the current density of the HSA anode membrane and electrode assembly（MEA） reaches 168 mA/cm2 at 0.5 V and 232.4 mA/cm2 at 0.2 V, and its power density reaches the maximum value of 84 mW/cm2. The influence of operating temperature and hydrogen pressure on the electrocatalytic behavior of HSA anode MEA is also discussed. At 60 ℃ under 2.02×105 Pa H2, the HSA anode shows the best electrochemical properties.

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

Synthesis of nanostructured Mg_2FeH_6 hydride and hydrogen sorption properties of complex

Reactive mechanical alloying(RMA)was carried out in a planetary ball mill for the synthesis of ternary hydride Mg2FeH6 for hydrogen storage.The formation mechanism of Mg2FeH6 in RMA process and the sorption properties of the products were investigated.The results show that Mg2FeH6 has a yield ratio around 80%,and a grain size below 10 nm in the powder synthesized by milling 3Mg+Fe mixture for 150 h under the hydrogen pressure of 1 MPa.The synthesized powder possesses a high hydrogen capacity and good sorption kinetics,and absorbs 4.42%(mass fraction)of hydrogen within 200 s at 623 K under the hydrogen pressure of 4.0 MPa.In releasing hydrogen at 653 K under 0.1 MPa,it desorbs 4.43%(mass fraction)of hydrogen within 2 000 s.The addition of Ti increases the hydrogen desorption rate of the complex in the initial 120 s of the desorption process.

Structural and hydrogen storage capacity evolution of Mg_2FeH_6 hydride synthesized by reactive mechanical alloying

Mg-based metal hydrides are promising as hydrogen storage materials for fuel ce ll application. In this work,Mg2FeH6 complex hydride phase was synthesized by controlled reactive ball milling of 2Mg-Fe （atomic ratio） powder mixture in H2. Mg2FeH6 is confirmed to be formed via the following three stages: form ation of MgH2 via the reaction of Mg with H2,incubation stage and formation of Mg2FeH6 by reaction of fully refined MgH2 and Fe. The incubation stage is characterized by no traces of Mg or hydride crystalline phase by XRD. On the other hand,Mg is observed uniformly distributed in the milled powder by SEM-E DS. Also,almost the same amount of H2 as the first stage is detected stored i n the powders of the second stage by DSC and TGA.

Compact Electric Energy Storage for Marine Vehicles Using on-Board Hydrogen Production

The use of electric energy in marine vessels has been increasing in recent years. In general, it is motivated by the low ecological impact. However, in the case of underwater vehicles it is functionally essential. The objective of this study is to demonstrate the advantage of electric power generation and storage based on on-board hydrogen generation via the reaction between activated aluminum and water and application of the hydrogen in a fuel cell. The original activation process enabling a spontaneous reaction with water to produce hydrogen as well as a parametric study of hydrogen generation rate and yield are briefly described. The potential increase in specific energy （energy per unit mass） and energy density （energy per unit volume） vs. batteries and other means of hydrogen storage is presented. It is shown that the use of the present technology may result in a substantial increase of specific electric energy along with a reduction in volume or an increase in operating time for the same overall mass of energy storage and generation system.

车用氢能发展难点与对策

“双碳”目标背景下,国内加快能源转型步伐,交通运输业作为第三大碳排放行业,加快向电、氢转型。分析了国内氢燃料电池汽车和加氢站的发展现状,从产业链的角度深入剖析了国内车用氢能发展的“车贵”“氢贵”“站贵”等三大痛点,认为深层次的原因是燃料电池、车辆生产和加氢站设备生产存在技术瓶颈,关键零部件仍然依赖进口,加氢站建设及运营成本高,电解水等制氢成本高等。最后,从行业发展的角度,分别提出了降低车用氢能成本的突破路径,指导行业良性发展。

氢能技术及其在车用领域应用现状综述

化石燃料的快速消耗迫切地需要寻找绿色清洁的替代能源,氢能是一种来源丰富、绿色低碳、应用广泛的二次能源,具有高能量、无污染的特性,是当下重要的工业原料。本文较为全面地分析了氢能的制取与储存,并且围绕氢能在车用领域的应用,因为在碳峰值和碳中和的背景下,内燃机行业的发展正面临着最好的转型机遇。加快氢发动机关键技术的研发和应用已成为世界各国政府和各大汽车企业的重要战略。本文对比了氢燃料电池与氢燃料内燃机的特点,对未来氢能源利用的产业化前景进行了分析。

基于多端口直流变压器的氢燃料电池-储能协调控制策略

面向氢燃料电池在微网领域日趋广泛的应用,依托宁波慈溪氢电耦合直流微网示范工程中的风/光/氢燃料电池直流互联系统,研究其氢燃料电池接入的核心设备——三端口直流变压器的端口功率协调控制策略。为缩短仿真时间,提出并采用了一种适用于多模块串并联多有源桥结构直流变压器的开关周期平均模型,并应用该等效简化模型提出了一种燃料电池-储能混合供电系统能量协调控制策略。该控制策略可根据储能系统荷电状态、各端口功率容量、燃料电池动态响应速度等因素对各端口功率指令进行优化调整与智能分配,避免燃料电池发电功率过快变化、储能系统过充过放,并最大化氢能发电占比。经实际样机测试与MATLABSimulink仿真验证,该协调控制策略在直流变压器的多种控制模式下均有良好的工作性能,功率控制端口的实际功率可以跟随快速变化的指令值,负荷突变时电压控制端口的实际电压波动均能控制在4%以下。

双向可逆的集中式电氢耦合系统容量优化配置

针对风光富集地区大型新能源发电厂的弃风弃光问题,利用可逆固体氧化物燃料电池(reversible solid oxide fuel cell,RSOC)结合氢储能的双向转换特性消纳多余风光资源,提出一种双向可逆的集中式RSOC电氢耦合系统容量优化配置方法。首先构建集中式RSOC电氢耦合系统架构,建立发电系统、电氢转换系统等模型;其次考虑燃料电池特性建立RSOC性能衰减模型,考虑特高压通道可用传输能力不确定性生成典型场景;进而建立集中式RSOC双层容量规划模型,上层以运营期收益最大为目标优化RSOC、储氢库容量配置,下层以综合成本最低为目标优化各设备出力,联合粒子群算法与Cplex求解器进行求解。最后通过算例分析,验证RSOC的加入提高了系统经济性及环境效益,同时投资灵敏度分析表明电池单位容量成本是制约系统经济运行的重要因素。

固体氧化物电解池的发展及研究现状

固体氧化物电解池(SOEC)可以高效、清洁地与可再生能源进行耦合并将其转化为化学能,是一种高效、环保的能量转化装置,但是存在长期运行性能衰减问题,这个问题也是固体氧化物电解水制氢实现大规模商业化的关键所在。本文简要介绍了SOEC的发展历程、类别及其组成和运行原理;详细阐述了该项技术的优、缺点及运行成本;重点对SOEC性能衰减的因素进行了分析,SOEC的组成、运行模式、连接板材料及运行条件等是造成性能衰减的主要因素;最后通过论文和专利数量分析了固体氧化物电解池的研究现状和未来发展趋势,认为虽然固体氧化物燃料电池(SOFC)发展较为成熟,但迫于目前环境需求,为了充分利用清洁能源,降低碳排放,SOEC制氢技术的大规模商业化必然是未来行业的发展方向,目前SOEC性能的稳定及低成本制备是该技术发展面临的主要问题。

基于PEM电解槽的风氢耦合系统能量管理研究

构建包含永磁同步直驱风电机组、质子交换膜电解槽、高压储氢罐、氢燃料电池耦合于交流母线的风氢耦合一体化系统。依照各单元自身物理约束条件及典型运行场景模式,提出一种包含9种运行工况的风氢耦合能量管理策略,使分散式风电与负荷需求之间的功率差值能完全被PEM电解槽与燃料电池消纳或补偿,保证分散式风电系统功率动态平衡。仿真结果表明,所提能量管理策略能有效协调分散式风电与制氢电解槽和负荷间功率流动,保证风氢耦合一体化系统多时间尺度下协同稳定运行。

基于固态储氢与燃料电池耦合的车载氢能源系统建模与特性分析

探讨了一种使用金属氢化物储氢罐和质子交换膜燃料电池的车载氢能源系统,旨在通过数学建模和工况测试评估氢能源系统内部的热量耦合效应。基于热交换系统结构和换热特性提出了氢能源系统多物理场模型,又基于增程式燃料电池物流车运行工况进行了数值模拟和试验验证。结果表明,所提出的数学模型能准确表征车载氢能源系统的动态特性,功率响应与温度动态变化具有显著的一致性。借助热交换系统提供热量补充,低温条件下固态储氢罐释氢速度加快,提高氢能源系统的动态响应速度和能源利用效率。研究结果可用于基于固态储氢与燃料电池耦合的氢能源系统最优尺寸设计、温度控制和能量管理策略设计。

基于固态储氢技术的分布式光伏发电并网系统研究

在新能源发电技术中,分布式光伏发电因选址灵活、噪声小、污染轻等优点而得到广泛应用,但光伏发电高峰多集中在白昼,而用电高峰多集中在夜晚,发电、用电高峰不匹配,造成大量“弃光”问题。以传统分布式光伏发电并网系统为基础,结合电解水制氢、固态储氢、燃料电池发电技术,提出一种基于固态储氢技术的分布式光伏发电并网系统,有效解决了“弃光”问题,可进一步提高电力系统光伏消纳水平。

“双碳”视域下氢燃料电池汽车储氢技术现状及发展方向

车载储氢技术是开发高效、安全、低成本氢燃料电池汽车的关键,而储氢材料是研究的重点之一,也是氢的储存和输送过程中的重要组成部分。综述了已采用或正在研究的储氢技术,金属储氢、高压气态储氢、液态储氢和复合储氢等,比较了各种储氢技术的优缺点并指出了车载储氢技术的发展方向。

氢燃料电池支线飞机关键技术与发展展望

氢燃料电池支线飞机是全球航空运输业实现绿色低碳目标的重要发展方向。本文分析了氢燃料电池支线飞机的发展现状和关键技术,包括液氢存储系统、氢燃料电池、电动机、氢燃料生产和储运加注等,预测了我国氢能航空技术发展趋势,并提出了包含各类新能源航空器产品的技术方案图谱,为我国氢能航空的发展提供理论支撑和方向指引。研究认为,我国将在2025—2035年逐步具备发展支线到窄体干线氢能飞机的技术条件,基于成熟国产飞机平台进行氢动力改装,以新能源技术变革推动航空制造业“换道超车”。

基于博弈论的含氢微网多主体能源系统优化配置

随着氢储能技术的不断发展,含氢微网中包含多个主体电源的容量合理配置问题将是今后推进电氢融合的重要方向之一。文中针对风光氢微网系统之间的合理配置问题展开研究。首先,考虑风光氢三方个体的收益模式,以风光出力为前提,氢储能实现电网剩余功率消纳,构建多主体收益模型;其次,针对氢储能制氢侧采用质子交换膜电解槽和碱性电解槽混合方法,以制氢收益与消纳率为目标,构建混合制氢配置模型;最后,采用NSGA-Ⅱ算法计算各主体纳什均衡点求解各主体配置结果。结合西北某地区典型月风速、光照场景数据进行计算,仿真结果表明,通过优化配置后多主体能源参与博弈后整体系统收益提升6.8%,实现了能源消纳;同时在采用混合制氢设备后,氢储能主体收益提升2.64%,负荷中断率相较单一制氢降低14%,改善了系统经济性和可靠性。