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     

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     

氢能及生命氢

氢能作为理想的清洁能源之一，已广泛引起人的重视。许多科学家认为，氢能在２１世纪能源舞上将成为一种举足轻重的能源。氢能，是指氢与氧反应放出的能量。作为能，氢能有以下主要特点：（１）能量高。除核燃外，氢的发热值是目前所有燃料中最高的（是汽的３倍）。氢的高能，使氢成为推进航天器的重要料之一。（２）氢本身无毒，燃烧产物是水，无染，且能循环使用。（３）氢燃烧性能好，点燃。（４）利用形式多，可以以气态、液态或固定属氢化物出现，能适应贮运及各种应用环境的不要求。然而在实际应用中，制氢储氢输氢等环节存在若干问题…     

发动机冷却余热利用技术的专利情况

燃料在发动机内通过燃烧之后,其化学能转化为热能,其中一部分通过内燃机循环变成有用功,驱动汽车运动,其余部分以发动机冷却余热和尾气余热形式排放到大气中。研究表明：燃料的化学能仅仅利用了30％左右,另外约70％通过发动机散热和高温尾气排热基本上全部浪费了。     

超临界氢存储技术的研究进展

氢能的利用是当今世界发展必然趋势,使用超临界氢存储技术可对氢能进行储存。介绍了超临界氢,并详细分析了超临界储氢、气态压缩储氢和低温液态储氢的优缺点。然后,对超临界储氢技术进行了详细论述,介绍了超临界吸附储氢和低温压力容器储存超临界氢两种技术的研究进展。最后,根据超临界氢存储技术的研究现状,提出了一些对超临界氢存储技术的发展及应用具有一定指导意义的建议。     

氢内燃机异常燃烧的研究

进气管喷射式氢内燃机目前被广泛应用,但其易发生早燃、敲缸和回火等异常燃烧现象,严重影响其正常工作。通过全面分析国内外关于早燃、敲缸、回火等异常燃烧的研究成果,找出异常燃烧的产生原因和影响因素,归纳总结出异常燃烧的控制方法,将会对进气管喷射式氢内燃机的正常工作起到重要的指导作用。     

光解氢：介绍几种利用太阳能制氢的方法

氢,将是活跃在21世纪能源舞台上的新秀.电解水制氢,是一种传统的制氢工艺,已有上百年的历史,但是它的效率低、电耗大、成本高,人们自然会联想到能不能利用太阳能制氢.地球每秒钟可以从太阳光中获得相当于590万吨标准煤的热量,可以说是制取氢能的不竭能源. 这里介绍几种利用太阳光制氢——光解氢的方法.     

有机液体与储氢材料组成的浆液储氢体系的能量分析

对C6H6/C6H12-LaNi5/LaNi5H6-H2组成的浆液储氢体系的储、放氢过程进行了能量衡算,提出了两种车载氢源系统的概念设计:随车脱氢和随车加氢-脱氢系统。考察了两种车载氢源系统的脱氢转化率和系统运行过程中放出的废热利用率对整个车载氢源系统热效率的影响,并就两种车载浆液氢源系统与氢内燃机或燃料电池构成的氢能汽车动力系统的能效进行了评估。研究表明,无论是采用氢内燃机还是燃料电池作为氢能汽车的动力驱动方式,车载浆液氢源系统在能效上是经济、可行的。     

面向碳中和情景的中国跨区域电氢协同优化配置研究

为实现碳中和目标,构建高比例清洁能源电力系统势在必行。绿氢可为难以直接用电的终端用能领域提供零碳解决方案,成为可再生能源和部分终端用能之间的纽带,实现间接电能替代。如何在高比例清洁能源系统中对电能与氢能进行优化配置,是未来电力、绿氢发展中需要面对的重要问题。通过构建的电氢协同系统模型(GTSEP),量化评估电氢耦合的系统性价值,分析输电、输氢之间的关系,以全系统综合用能成本最低为目标,实现全国范围内大规模、跨区域电力与氢能生产、储存和运输的协调优化。将全国划分为七个区域,预计2060年绿氢需求量为7500×104t,全社会用电量需求将达到17×1012kW·h,根据满足绿氢需求的不同方式,共设置4种模式进行对比分析。结果表明,采用电氢协同模式,各区域内利用可再生能源发电就地制氢并利用的总量为4000×104t,跨区输氢总量3500×104t,约占总需求的46%左右,其中直接管道输氢780×104t,输电代输氢1.1×1012k W·h,绿氢平准化成本为9.32元/kg。电氢协同的零碳能源系统可以充分发挥氢易于大规模存储的优点和电能易于传输的特点。     

国际氢安全领域研究热点及最新进展——记第五届国际氢安全会议(ICHS 2013)

国际氢安全会议是氢安全领域的国际顶级会议,受到各国学术界、工程界和政府部门的高度重视。第五届国际氢安全会议(ICHS 2013)在比利时布鲁塞尔召开,会议的主题是"氢能技术与基础设施安全的新进展:向零碳能源进发"。大会共设9大类议题——氢气泄漏与扩散、氢气燃烧与爆炸、储氢安全、风险评估、氢与材料相容性、燃料电池安全、氢传感器、规范标准、氢安全教育,共收录论文99篇,组织报告会29场,重点关注的研究领域集中在氢气行为(泄漏、扩散、燃烧、爆炸)、储氢安全、风险评估三个方面。英、法、美、德四国是ICHS 2013文章收录数量的第一梯队,也是氢安全领域研究的主力军和ICHS的重要参与者。加拿大、日本、中国、荷兰排在文章收录数量的第二梯队。美、日、欧盟等氢能领域先进国家或地区都在积极研发推广氢能技术。我国在ICHS 2013的论文发表数量和领域覆盖面上都与先进国家存在一定差距,今后应积极投稿并参加会议,提升我国在氢安全领域的国际影响力和话语权。     

Thermodynamics analysis of hydrogen storage based on compressed gaseous hydrogen,liquid hydrogen and cryo-compressed hydrogen

Safe, reliable, and economic hydrogen storage is a bottleneck for large-scale hydrogen utilization. In this paper, hydrogen storage methods based on the ambient temperature compressed gaseous hydrogen (CGH₂), liquid hydrogen (LH₂) and cryo-compressed hydrogen (CcH₂) are analyzed. There exists the optimal states, defined by temperature and pressure, for hydrogen storage in CcH₂ method. The ratio of the hydrogen density obtained to the electrical energy consumed exhibits a maximum value at the pressures above 15 MPa. The electrical energy consumed consists of compression and cooling down processes from 0.1 MPa at 300 K to the optimal states. The recommended parameters for hydrogen storage are at 35–110 K and 5–70 MPa regardless of ortho-to parahydrogen conversion. The corresponding hydrogen density at the optimal states range from 60.0 to 71.5 kg m⁻³ and the ratio of the hydrogen density obtained to the electrical energy consumed ranges from 1.50 to 2.30 kg m⁻³ kW⁻¹. While the ortho-to para-hydrogen conversion is considered, the optimal states move to a slightly higher temperatures comparing to calculations without ortho-to para-hydrogen conversion.     

Robust hydrogen detection system with a thermoelectric hydrogen sensor for hydrogen station application

A prototype hydrogen detection system using the micro-thermoelectric hydrogen sensor (micro-THS) was developed for the safety of hydrogen infrastructure systems, such as hydrogen stations. We have designed a detection part with a pressure proof enclosure adoptable for the international standard of Exd II CT3, and carried out an explosion strength test, explosion and fire hazard tests, and an impact test. The hydrogen sensing performance of the detection part of this prototype system showed a good linear relationship between the sensing signal and hydrogen concentrations in air, for a wide range of hydrogen concentrations from 10 ppm to 40,000 ppm (4 vol.%). This prototype detection system was installed in the outdoor field of the hydrogen station and the response for H₂ gas in air of 100 ppm, 1000 ppm, and 10000 ppm was tested monthly for 1 year.     

Pressurized hydrogen from charged liquid organic hydrogen carrier systems by electrochemical hydrogen compression

We demonstrate that the combination of hydrogen release from a Liquid Organic Hydrogen Carrier (LOHC) system with electrochemical hydrogen compression (EHC) provides three decisive advantages over the state-of-the-art hydrogen provision from such storage system: a) The EHC device produces reduced hydrogen pressure on its suction side connected to the LOHC dehydrogenation unit, thus shifting the thermodynamic equilibrium towards dehydrogenation and accelerating the hydrogen release; b) the EHC device compresses the hydrogen released from the carrier system thus producing high value compressed hydrogen; c) the EHC process is selective for proton transport and thus the process purifies hydrogen from impurities, such as traces of methane. We demonstrate this combination for the production of compressed hydrogen (absolute pressure of 6 bar) from perhydro dibenzyltoluene at dehydrogenation temperatures down to 240 °C in a quality suitable for fuel cell operation, e.g. in a fuel cell vehicle. The presented technology may be highly attractive for providing compressed hydrogen at future hydrogen filling stations that receive and store hydrogen in a LOHC-bound manner.     

Green hydrogen standard in China: Standard and evaluation of low-carbon hydrogen,clean hydrogen,and renewable hydrogen

With the proposal of carbon neutral goals in various countries, the deepening of global action on climate change and the acceleration of green economy recovery in the post epidemic era, building a low-carbon and clean hydrogen supply system has gradually become a global consensus. In order to promote the development of clean hydrogen market, the standards of green hydrogen have been discussed at global level. The quantitative definition of different hydrogen production methods based on the greenhouse gases (GHG) emission of life cycle assessment (LCA) methods is gradually recognised by the industry. China issued the “Standard and evaluation of low-carbon hydrogen, clean hydrogen and renewable hydrogen” in December 2020. This is the first formal green hydrogen standard worldwide, which provides calculation methods for GHG of different hydrogen production paths. This chapter discusses the major green hydrogen standards initiative in the world, analyses the key factors of the global green hydrogen standard, and introduces how to establish the quantitative standards and evaluation system of low-carbon hydrogen, clean hydrogen, and renewable hydrogen by using the method in China.     

In-situ hydrogen wettability characterisation for underground hydrogen storage

Hydrogen storage in subsurface aquifers or depleted gas reservoirs represents a viable long-term energy storage solution. There is currently a scarcity of subsurface petrophysical data for the hydrogen system. In this work, we determine the wettability and Interfacial Tension (IFT) of the hydrogen-brine-quartz system using captive bubble, pendant drop and in-situ 3D micro-Computed Tomography (CT) methods. Effective contact angles ranged between 29° and 39° for pressures 6.89–20.68 MPa and salinities from distilled water to 5000 ppm NaCl brine. In-situ methods, novel to hydrogen investigations, confirmed the water-wet system with the mean of the macroscopic and apparent contact angle distributions being 39.77° and 59.75° respectively. IFT decreased with increasing pressure in distilled water from 72.45 mN/m at 6.89 MPa to 69.43 mN/m at 20.68 MPa. No correlation was found between IFT and salinity for the 1000 ppm and 5000 ppm brines. Novel insights into hydrogen wetting in multiphase environments allow accurate predictions of relative permeability and capillary pressure curves for large scale simulations.     

Liquid hydrogen production via hydrogen sulfide methane reformation

Hydrogen sulfide (H₂S) methane (CH₄) reformation (H₂SMR) (2H₂S + CH₄ = CS₂ + 4H₂) is a potentially viable process for the removal of H₂S from sour natural gas resources or other methane containing gases. Unlike steam methane reformation that generates carbon dioxide as a by-product, H₂SMR produces carbon disulfide (CS₂), a liquid under ambient temperature and pressure—a commodity chemical that is also a feedstock for the synthesis of sulfuric acid. Pinch point analyses for H₂SMR were conducted to determine the reaction conditions necessary for no carbon lay down to occur. Calculations showed that to prevent solid carbon formation, low inlet CH₄ to H₂S ratios are needed. In this paper, we analyze H₂SMR with either a cryogenic process or a membrane separation operation for production of either liquid or gaseous hydrogen. Of the three H₂SMR hydrogen production flowsheets analyzed, direct liquid hydrogen generation has higher first and second law efficiencies of exceeding 80% and 50%, respectively.     

Liquid hydrogen

It would be helpful were it economically acceptable to liquefy hydrogen. However, methanol is a liquid and could be written CH₄O. The Nobel Laureate, George Olah along with two co-enthusiasts, published a book (2006) entitled “A Methanol ECONOMY”.³ If the methanol is synthesized from hydrogen and CO₂ from the atmosphere, burning it as a fuel would merely replace in the atmosphere the CO₂ taken from it and in the synthesis of the methanol.Let us, therefore, add “LIQUID HYDROGEN”³ to the subdivisions of uses of HYDROGEN.