有机液态氢化物可逆储放氢技术的研究现状与展望

以甲基环己烷－甲苯－氢（MTH系统）与环己烷－苯－氢（CBH系统）为例介绍了有机物可逆储放氢技术的特点与研究现状。研究表明，该技术作为大规模、长期性的氢能储存和运输手段，作为随车脱氢为汽车提供氢燃料或为氢燃料电池提供氢源，以及用于化学热泵等在技术上都是可行的，但问题的关键是如何提高过程的释氢效率，特别是低温下的释氢效率，开发低温高效脱氢催化剂和采用膜催化反应分离技术是提高释氢过程效率的可行方法。水电解－有机氢载体电化学加氢－氢载体膜催化脱氢技术路线有望改善系统储氢效能，实现氢的高能量密度储存。     

有机液体氢化物贮氢新技术研究Ⅲ.氢燃料汽车的系统分析

对基于甲基环己烷（ＭＣＨ）－甲苯（ＴＯＬ）－氢（Ｈ２）的一对高度可逆反应的贮氢技术进行了较系统的研究，利用考虑随车脱氢环境的ＭＣＨ脱氢实验研究结果，对一种发动机功率为２０ｋＷ的小型氢燃料车进行了初步设计，并对ＭＴＨ贮氢技术进行了系统的能流和物流分析。结果表明，ＭＣＨ随车脱氢供汽车氢燃料在小型汽车上应用是可行的，其贮氢 能效可达０．５９。     

氢能汽车

正氢能汽车,是以氢作为能源的汽车,将氢反应所产生的化学能转换为机械能推动车辆。氢能汽车分为两种,一种氢内燃机汽车(HICEV)是以内燃机燃烧氢气(通常透过分解甲烷或电解水取得)产生动力推动汽车。另一种氢燃料电池车(FCEV)是使氢或含氢物质与空气中的氧在燃料电池中反应产生电力推动电动机,由电动机推动车辆。使用氢为能源的最大好处     

氢能性能卓越,氢燃料电池将结束内燃机时代

正对氢能的应用主要是通过氢燃料电池来实现的。氢燃料电池的工作方式从本质上不同于内燃机,氢燃料电池通过化学反应产生电能来推动汽车,而内燃机车则是通过燃烧产生热能来推动汽车。由于燃料电池汽车工作过程不涉及燃烧,因此无机械损耗及腐蚀,氢燃料电池所产生的电能可以直接被     

车载高压储氢压力容器技术的特点与发展趋势北大核心CSCD

氢气燃烧时不会产生污染，是极具潜力的二次能源。20世纪以来，世界各国对于氢能源开发与利用的重视程度不断提高。相比化石燃料，氢气无论是应用于内燃机还是燃料电池，都具有更高的效率。储氢也逐渐成为了氢能产业链的核心环节。中国立足碳达峰、碳中和目标，积极推动氢能产业发展，氢能产业发展潜力正逐渐释放，并将逐步成为中国能源战略的重要组成部分。随着氢能在汽车动力中的应用，车载高压储氢压力容器技术也将快速发展。     

燃料电池车车载储氢系统的技术发展与应用现状

综述了燃料电池车车载储氢系统技术，包括高压氢、液氢、金属氢化物、低温吸附、纳米碳管高压吸附以及液体有机氢化物等的研究进展及其车载应用现状。参照燃料电池车对车载储氢系统单位重量储氢密度与体积储氢密度的目标要求，对目前已应用和处于研发阶段的一些储氢技术的性能指标和存在问题进行了分析讨论。同时对目前该领域的若干新的研究报道，如超高压轻质复合容器、混合储氢容器、b.c．c．储氢合金、超级活性碳和“浆液”双相储氢等，也作了简要介绍。     

氢能知识系列讲座(7)氢内燃机和氢燃料

氢气的常规利用方式主要是两种,一种是通过电化学方法,利用我们前两讲介绍的"燃料电池"将氢的化学能变为电能和热能;另一种方式是通过热化学方式,即燃烧氢,将化学能变成热能或动能。例如,用锅炉将氢能变成热能,用"内燃机"将氢能变成动能。本讲就是介绍氢内燃机。"内燃机"是一种动力机械,它是通过燃料在汽缸内燃烧,将放出的热能直接转换为动力的热力发     

燃料电池汽车氢能系统的环境、经济和能源评价

为了推动氢能系统评价工作的深入进行并为我国在近期发展燃料电池汽车氢能系统(包括燃料电池汽车及其氢源)提供有价值的参考，根据现有的生产、储存和输运氢的技术，设计了11种可行方案，运用生命周期评价方法对这些方案的环境性、经济性和能源利用情况进行了评价，得到了每种方案的分类环境效应指数、氢气总成本和总能量利用效率。结果表明，综合指标最优的燃料电池汽车氢能系统方案是：天然气集中制氢厂制氢，然后用汽车将装有氢气的高压钢瓶输运到加氢站，加注给以氢气为燃料的燃料电池汽车。     

舟山市首辆氢能冷链车亮相六横

近日,由浙江锡力科技与东风汽车联合打造的氢能燃料电池冷链车首度亮相六横,接下来将按计划打造"全市首批氢能运输车队"。这辆氢能燃料电池冷链车总质量为8 990 kg,与常规冷链车不同,该车动力由浙江锡力科技自主研发生产的50 kW氢能燃料电池系统提供,并装有3个5 kg氢气罐,可装载氢气15 kg,为燃料电池系统供能。     

面向车载深冷高压供氢系统的控制策略研究

提出一种深冷高压储供氢系统的实时控制策略,用于管理控制燃料电池卡车的氢能储供过程。首先,基于流体热力学模型建立深冷高压储氢瓶泄放模型,预测氢的状态参数变化。其次,结合车辆热管理系统,设计一种新型深冷高压氢供给系统,综合利用燃料电池"废热"和深冷高压"冷能"。最后,通过数值建模对换热器运行参数进行定量研究,优化了控制策略。整体动态响应机制既满足了燃料电池正常运行的要求,又提升了整车能量利用率。     

Automotive storage of hydrogen in alane

Although alane (AlH₃) has many interesting properties as a hydrogen storage material, it cannot be regenerated on-board a vehicle. One way of overcoming this limitation is to formulate an alane slurry that can be easily loaded into a fuel tank and removed for off-board regeneration. In this paper, we analyze the performance of an on-board hydrogen storage system that uses alane slurry as the hydrogen carrier. A model for the on-board storage system was developed to analyze the AlH₃ decomposition kinetics, heat transfer requirements, stability, startup energy and time, H₂ buffer requirements, storage efficiency, and hydrogen storage capacities. The results from the model indicate that reactor temperatures higher than 200 °C are needed to decompose alane at reasonable liquid hourly space velocities, i.e., > 60 h⁻¹. At the system level, a gravimetric capacity of 4.2 wt% usable hydrogen and a volumetric capacity of 50 g H₂/L may be achievable with a 70% solids slurry. Under optimum conditions, 80% of the H₂ stored in the slurry may be available for the fuel cell engine. The model indicates that H₂ loss is limited by the decomposition kinetics rather than by the rate of heat transfer from the ambient to the slurry tank.     

Seasonal storage of hydrogen in stationary systems with liquid organic hydrides

A comparison of energy storage media for carbon free systems was made on a cost and weight basis for application with renewable energy sources such as hydropower. On a seasonal timescale (summer to winter), storage of hydrogen in liquid organic hydrides was equivalent to other carbon free alternatives and superior to zero emission systems like batteries.Seasonal energy storage is illustrated by the methylcyclohexane-toluene-hydrogen (MTH) system. Low cost summer electricity is used for water electrolysis to yield hydrogen for hydrogenation of toluene. Dehydrogenation in winter gives hydrogen for heat and power generation by fuel cells with an estimated overall electrical efficiency of 41%. Recent laboratory results using commercial, dehydrogenation catalysts in fixed bed reactors show how catalyst efficiency was increased (low by-products) to reduce the carbon emissions to 0.01 kgC/kWh_e. Hydrogen separation membranes and new molecular reactions are being investigated to further increase efficiencies. Economic analyses show that the seasonal storage of hydroelectric power with hydrogen by the MTH system is economically competitive with new hydropower projects.     

Integration of hydrogenation and dehydrogenation based on dibenzyltoluene as liquid organic hydrogen energy carrier

The heat transfer oil dibenzyltoluene (DBT) offered an intriguing approach for the scattered storage of renewable excess energy as a novel Liquid Organic Hydrogen Carrier (LOHC). The integration of hydrogenation and dehydrogenation in H0-DBT/H18-DBT pairs demonstrated that the feasibility of hydrogenation and dehydrogenation reaction conducted in one reactor with the same catalyst, which would be proposed to simplify the hydrogen storage process. The optimal reaction temperature based on the inhibition of ring opening and cracking was investigated combined with the ¹H NMR analysis. Meanwhile, the ideal catalyst 3 wt% Pt/Al₂O₃ for high hydrogen storage efficiency was screened out. Cycle tests of hydrogenation and dehydrogenation integration reaction had shown that the hydrogen storage efficiency was 84.6% after five cycle tests. The integration of hydrogenation and dehydrogenation reaction based on DBT exhibited the ideal thermal stability, which demonstrated its potential as a reversible H₂ carrier.     

Modeling of a thermal energy storage system based on coupled metal hydrides (magnesium iron – sodium alanate) for concentrating solar power plants

Concentrating solar power plants represent low cost and efficient solutions for renewable electricity production only if adequate thermal energy storage systems are included. Metal hydride thermal energy storage systems have demonstrated the potential to achieve very high volumetric energy densities, high exergetic efficiencies, and low costs. The current work analyzes the technical feasibility and the performance of a storage system based on the high temperature Mg₂FeH₆ hydride coupled with the low temperature Na₃AlH₆ hydride. To accomplish this, a detailed transport model has been set up and the coupled metal hydride system has been simulated based on a laboratory scale experimental configuration. Proper kinetics expressions have been developed and included in the model to replicate the absorption and desorption process in the high temperature and low temperature hydride materials. The system showed adequate hydrogen transfer between the two metal hydrides, with almost complete charging and discharging, during both thermal energy storage and thermal energy release. The system operating temperatures varied from 450 °C to 500 °C, with hydrogen pressures between 30 bar and 70 bar. This makes the thermal energy storage system a suitable candidate for pairing with a solar driven steam power plant. The model results, obtained for the selected experimental configuration, showed an actual thermal energy storage system volumetric energy density of about 132 kWh/m³, which is more than 5 times the U.S. Department of Energy SunShot target (25 kWh/m³).     

Numerical analysis of an energy storage system based on a metal hydride hydrogen tank and a lithium-ion battery pack for a plug-in fuel cell electric scooter

This work investigates on the performance of a hybrid energy storage system made of a metal hydride tank for hydrogen storage and a lithium-ion battery pack, specifically conceived to replace the conventional battery pack in a plug-in fuel cell electric scooter. The concept behind this solution is to take advantage of the endothermic hydrogen desorption in metal hydrides to provide cooling to the battery pack during operation.The analysis is conducted numerically by means of a finite element model developed in order to assess the thermal management capabilities of the proposed solution under realistic operating conditions.The results show that the hybrid energy storage system is effectively capable of passively controlling the temperature of the battery pack, while enhancing at the same time the on-board storage energy density. The maximum temperature rise experienced by the battery pack is around 12 °C when the thermal management is provided by the hydrogen desorption in metal hydrides, against a value above 30 °C obtained for the same case without thermal management. Moreover, the hybrid energy storage system provides the 16% of the total mass of hydrogen requested by the fuel cell stack during operation, which corresponds to a significant enhancement of the hydrogen storage capability on-board of the vehicle.     

Performance prediction of a coupled metal hydride based thermal energy storage system

The present study discusses the thermodynamic compatibility criteria for the selection of metal hydride pairs for the application in coupled metal hydride based thermal energy storage systems. These are closed systems comprising of two metal hydride beds – a primary bed for energy storage and a secondary bed for hydrogen storage. The performance of a coupled system is analyzed considering Mg₂Ni material for energy storage and LaNi₅ material for hydrogen storage. A 3-D model is developed and simulated using COMSOL Multiphysics® at charging and discharging temperatures of 300 °C and 230 °C, respectively. The LaNi₅ bed used for hydrogen storage is operated close to ambient temperature of 25 °C. The results of the first three consecutive cycles are presented. The thermal storage system achieved a volumetric energy storage density of 156 kWh m⁻³ at energy storage efficiency of 89.4% during third cycle.     

200 NL H2 hydrogen storage tank using MgH2–TiH2–C nanocomposite as H storage material

MgH₂-based hydrogen storage materials are promising candidates for solid-state hydrogen storage allowing efficient thermal management in energy systems integrating metal hydride hydrogen store with a solid oxide fuel cell (SOFC) providing dissipated heat at temperatures between 400 and 600 °C. Recently, we have shown that graphite-modified composite of TiH₂ and MgH₂ prepared by high-energy reactive ball milling in hydrogen (HRBM), demonstrates a high reversible gravimetric H storage capacity exceeding 5 wt % H, fast hydrogenation/dehydrogenation kinetics and excellent cycle stability. In present study, 0.9 MgH₂ + 0.1 TiH₂ +5 wt %C nanocomposite with a maximum hydrogen storage capacity of 6.3 wt% H was prepared by HRBM preceded by a short homogenizing pre-milling in inert gas. 300 g of the composite was loaded into a storage tank accommodating an air-heated stainless steel metal hydride (MH) container equipped with transversal internal (copper) and external (aluminium) fins. Tests of the tank were carried out in a temperature range from 150 °C (H₂ absorption) to 370 °C (H₂ desorption) and showed its ability to deliver up to 185 NL H₂ corresponding to a reversible H storage capacity of the MH material of appr. 5 wt% H. No significant deterioration of the reversible H storage capacity was observed during 20 heating/cooling H₂ discharge/charge cycles. It was found that H₂ desorption performance can be tailored by selecting appropriate thermal management conditions and an optimal operational regime has been proposed.     

Bulk nanocomposite MgH2/10 wt% (8 Nb2O5/2 Ni) solid-hydrogen storage system for fuel cell applications

Hydrogen, which holds tremendous promise as a new clean energy option is considered as an efficient source of primary energy. Unluckily, hydrogen storage presents the most crucial difficulty restricting utilization of hydrogen energy for real applications. However, Mg metal is the best known cheap solid-state hydrogen storage media with high hydrogen capacity and operational cost effectiveness; it shows high thermal stability and poor hydrogenation/dehydrogenation kinetics. In the present work we have succeeded to prepare nanocrystalline MgH₂ powders doped with a mixture of 8 wt% Nb₂O₅/2 wt% Ni nanocatalytic system. The synthesized nanocomposite powders possessed superior hydrogenation/dehydrogenation kinetics (2.6 min/3 min) at relatively low temperature (250 °C) with long cycle-life-time (400 h). The powders were consolidated into green-compacts, using cold pressing technique. The compacts were utilized as solid-state hydrogen source needed for charging a battery of a cell-phone device, using integrated Ti-tank/commercial proton-exchange membrane fuel cell system.     

Analysis of reaction mixtures of perhydro-dibenzyltoluene using two-dimensional gas chromatography and single quadrupole gas chromatography

Energy storage via liquid organic hydrogen carrier (LOHC) systems has gained significant attention in recent times. A dibenzyltoluene (DBT) based LOHC offers excellent properties which largely solve today's hydrogen storage challenges. Understanding the course of the dehydrogenation reaction is important for catalyst and process optimization. Therefore, reliable and exact methods to determine the degree of hydrogenation (doh) are important. We here present other possible techniques, namely: comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (2D-GC-TOF-MS) and single quadrupole-mass spectrometry gas chromatogram system (GC-SQ-MS). The 2D-GC-TOF-MS results indicate that isomer fractions lose three molecules of hydrogen, as follows: H18-DBT, H12-DBT, H6-DBT and H0-DBT, and the doh decreases with an increase in dehydrogenation temperature. ¹H NMR and GC-SQ-MS were employed as additional analytical techniques. The GC-SQ-MS was also used to analyse decomposition products that result from thermal cracking of reaction mixture molecules.     

Experimental determination of the hydrogenation/dehydrogenation - Equilibrium of the LOHC system H0/H18-dibenzyltoluene

Liquid organic hydrogen carrier (LOHC) systems store hydrogen through a catalyst-promoted exothermal hydrogenation reaction and release hydrogen through an endothermal catalytic dehydrogenation reaction. At a given pressure and temperature the amount of releasable hydrogen depends on the reaction equilibrium of the hydrogenation/dehydrogenation reaction. Thus, the equilibrium composition of a given LOHC system is one of the key parameters for the reactor and process design of hydrogen storage and release units. Currently, LOHC equilibrium data are calculated on the basis of calorimetric data of selected, pure hydrogen-lean and hydrogen-rich LOHC compounds. Yet, real reaction systems comprise a variety of isomers, their respective partially hydrogenated species as well as by-products formed during multiple hydrogenation/dehydrogenation cycles. Therefore, our study focuses on an empirical approach to describe the temperature and pressure dependency of the hydrogenation equilibrium of the LOHC system H0/H18-DBT under real life experimental conditions. Because reliable measurements of the degree of hydrogenation (DoH) play a vital role in this context, we describe in this contribution two novel methods of DoH determination for LOHC systems based on ¹³C NMR and GC-FID measurements.