氢能利用与碳质材料吸附储氢技术

氢能作为一种洁净的可再生能源,对整个世界经济的可持续发展具有重要的战略意义。碳质材料具有比表面积高,吸/脱附速度快,可循环使用,寿命长,容易实现规模化生产等优点,可显著促进低成本、规模化储氢技术的发展,对未来的能源、交通、环保而言具有非常重要的意义。综述了氢能开发利用的最新研究动态,展望了氢能利用和储存的发展趋势,在简要介绍氢能的制备方法、储氢材料和储氢技术的基础上,重点介绍了碳质材料吸附储氢技术。     

我国氢能产业发展现状与思考

我国以化石能源为消费主体,为加快实现"双碳"减排目标,发展清洁能源刻不容缓。从制氢、燃料电池、氢能汽车、加氢站和氢能冶金等方面对我国氢能发展现状进行梳理,分析了我国氢能产业的不足,并对未来氢能发展方向提出建议。研究表明,我国氢能产业处于初级发展阶段,尚未完全掌握氢能核心技术,关键材料及零部件仍依赖进口,导致氢能产业链的生产成本较高。未来我国应加强氢能顶层规划布局、氢能产业核心技术攻关、开展高效制氢技术及拓宽氢能应用场景,为未来氢能大规模发展打下坚实基础。     

氢能-煤基能源产业战略转型路径研究

在碳达峰、碳中和的战略目标下,煤基能源的兴衰关系到煤炭、煤电和煤化工上下游各个相关板块,影响面甚广。通过研究能源形态变革的演进规律发现,氢能是架起传统能源与新能源之间的桥梁,是可再生能源高比例发展的推进器,是煤化工/冶金产业转型发展的原料仓,是交通/电力领域多元发展的动力源,是未来电网平衡的稳定器。基于此,研究提出了氢能-煤基能源产业发展的契入点,布局氢源和制氢技术,建设通道,建立一体化产业发展模式,激活煤炭原料属性,实现CO_2零排放。最后阐述了氢能-煤基能源产业发展路径和建议,以切合国家能源发展战略,实现国家应对气候变化的总体目标。     

超声波分解醇类水溶液制氢

引言利用多种能源资源和发展高效、清洁的能源技术是能源发展的目标。氢能被认为是21世纪最有前途的新能源之一[1]。通过对有机废液的洁净转化获得氢能有重要的现实意义。甲醇水溶液超声波分     

化工大数据 图说氢能源

正氢能源氢能具有零污染、高效率、来源丰富、用途广泛等优点,被视为21世纪最具发展潜力的清洁能源。氢能已经被纳入我国能源发展战略,成为我国优化能源消费结构和保障国家能源供给安全的战略选择。在今年全国"两会"上,氢能源产业再蹭了波热点。我国氢能产业发展三阶段1近期(2016-2020年) 2中期(2020-2030年) 3远期(2030-2050年)     

氢能利用方式及发展前景

随着我国更加坚定地贯彻新发展理念,推进产业结构转型,走上以创新为驱动的绿色、低碳、循环的发展路径,实现"碳达峰""碳中和"目标,获取和使用新型能源十分迫切,氢能成为一笔不可忽视的能源财富。介绍了目前国内外氢能产业发展现状和近年推广的利用方式,分析了制氢、储氢及输氢的发展特点及存在瓶颈。在已有的氢能利用基础上,简述了未来促进氢能利用的研究重点。     

CO_2促进“甲醇经济”与“氢经济”共同发展

在"碳达峰"和"碳中和"背景下,如何快速实现碳减排任务重大,其中能源消费结构至关重要。在CO_2循环利用中,甲醇作为"碳载体"和"氢载体"可以促进氢能产业优化,解决氢气(H_2)难运输、难存储的瓶颈。针对富碳天然气和CO_2集中排放大户,充分利用甲醇和H_2之间的相互转化反应,提出富碳天然气-甲醇-氢能一体化技术和CO_2-H_2-甲醇一体化技术,通过CO_2实现H_2与甲醇互补和相互转化的能源终端供应系统,推动能源低碳转型。     

《广西氢能产业发展中长期规划》印发

<正>2023年8月10日，为促进广西氢能产业高质量发展，实现碳中和碳达峰目标，广西壮族自治区发展和改革委员会印发《广西氢能产业发展中长期规划（2023-2035年）》（以下简称规划）。规划指出，广西氢能来源广泛，制氢潜力大，且具有氢能应用场景，市场前景广阔，     

规模化氢液化装置现状及未来技术路线分析

氢能作为零碳能源,是实现我国双碳目标的有效战略途径,随着氢能被纳入我国能源体系范畴,氢能的广泛商业应用即将呈现爆发式增长。受限于氢的物理特性,氢能利用过程中的高能量密度储运技术一直是制约其发展的瓶颈之一,液氢作为储氢密度最大的方式,其规模化制取技术是解决氢能应用环节中高效储运和规模化利用的有效途径。本文对当前全球已知的规模化氢液化装置的液氢产能规模和运行状态进行了统计分析,介绍了主要生产国的工业氢液化装置,比较了三种基本氢液化原理,总结了实际工业装置特点,对当前提出的规模化概念型氢液化系统原理和能效进行了分析,提出了未来发展应参考的设计特点和建议性阶段发展方向,为氢能的高效规模化储运技术发展提供有效支持,加速实现氢能的广泛商业化应用。     

氢能源的利用现状分析

氢能是公认的清洁能源,它具有储运方便、利用途径多样、高利用率及来源广泛等特点,可为解决能源危机、全球变暖和环境污染提供帮助。当前,一些发达国家已将氢能列为国家能源体系中的重要组成部分,我国在氢能的研究及产业化方面也投入巨大。本文综合考虑氢能在能源和化工领域的应用,较为全面地总结了氢能作为清洁能源在燃料电池汽车、分布式发电、燃料电池叉车和应急电源,作为能源载体在可再生能源消纳以及作为重要化工原料在油品质量升级和煤制清洁能源各方面的国内外利用现状,分析明确了氢清洁能源的利用是目前推动氢能发展的主要动力,氢能源载体的利用有助于可再生能源和氢能的协同发展,而氢化工原料的利用则是目前最有希望实现氢能规模化利用的有效途径,同时指出氢的制取、储运和燃料电池技术依然是制约氢能发展的关键因素。     

Effect of KI and KOH Impregnations over Activated Carbon on H2S Adsorption Performance at Low and High Temperatures

In the present work, commercial-grade activated carbon was modified by steam activation to improve its surface properties for high temperature desulfurization. The modified sample was also further upgraded by impregnating with KOH and KI to promote the chemisorption with of H₂S. The H₂S adsorption performance was tested under the temperature range of 30–550°C using the temperature program adsorption technique to understand the effect of adsorption temperature on the material adsorption characteristic. It was found that at ambient temperature, the impregnation of activated carbon with KOH can promote the H₂S adsorption capacity of activated carbon, whereas the impregnation with KI does not provide a significant beneficial effect. At high adsorption temperature (upto 550°C), both KOH and KI impregnation considerably improve the H₂S adsorption performance of activated carbon in terms of the adsorption capacity and breakthrough time. It was revealed from N₂ adsorption, SEM and EDS measurement that the chemical reactions between H₂S and alkaline compounds (KOH and KI) are promoted at high temperature. Based on all experimental results, the equilibrium adsorption model using the linear isotherm was developed to predict the adsorption behavior of these sorbents in terms of equilibrium isotherm constant and mass transfer coefficient for later scaling-up process.     

STORAGE OF HYDROGEN ON CARBON MATERIALS: EXPERIMENTS AND ANALYSES

Superactivated carbon and carbon nanotubes are both considered potential hydrogen carriers. Adsorption isotherms of H₂ on activated carbon AX-21 and multi-wall carbon nanotubes were collected with a volumetric method for the temperature range of 77, 233–298 K and pressures up to 7 or 10 MPa. Based on the experimental data for 233–298 K, the limiting heats of adsorption of 7.6 and 1.8 kJ/mol were obtained for activated carbon and carbon nanotubes, respectively. The absolute adsorption was determined with a recently presented method, and the adsorption behavior of H₂ on carbon nanotubes was thus reasonably explained. A comparison was given for the storage capacities of compression alone and of filling powder or pellets of the two materials. It was concluded that adsorption of H₂ on carbon nanotubes is too weak to enhance storage, but activated carbon enhances storage capacity considerably. The weight percentage of hydrogen stored in carbon powder reaches 10.8% at 77 K and 6 MPa, including the quantity compressed in the void space, and 4.1 kg H₂ was stored in a 100-liter container filled with carbon pellets for the same condition.     

Ni-doped carbon xerogels for H2 storage

Activated carbon xerogels, with selected characteristics, were doped with Ni, using different methods, and tested for hydrogen storage. The results obtained show that the amount of nickel incorporated, the Ni-carbon interaction and the nickel particle size distribution depend more on the doping method used than on the textural properties of the carbon support. The amount of nickel incorporated by strong electrostatic adsorption is lower than that incorporated by dry impregnation. However, the strong electrostatic adsorption method produces Ni-doped carbon xerogels with a high Ni-carbon interaction and a narrower Ni particle size distribution. The influence of Ni on H₂ storage capacity depends on the operating conditions and the doping conditions used. Thus, at −196 °C and 40 bar, storage capacity seems to be mainly influenced by the textural properties of carbon support while, at 25 °C and 200 bar, the spillover effect plays a significant role, being the interaction between the support and Ni particles key factor in the storage process. The best Ni-doped carbon xerogels obtained in this work exhibit hydrogen storage capacities of 6 wt.% and 31.8 g l⁻¹ at −196 °C and 40 bar.     

Influence of sample cell physisorption on measurements of hydrogen storage of carbon materials using a Sieverts apparatus

In recent years, large fluctuations have been reported for measurements of the hydrogen storage of carbon materials using a Sieverts apparatus. To investigate this problem, helium gas adsorption was selected for comparison with the adsorption of hydrogen, and the results show that hydrogen but not helium was adsorbed onto the wall of the sample cell at ambient temperature. The adsorption capacity of the sample cell at 77 K is higher than that at ambient temperature. A series of adsorption tests was conducted with a LaNi₅ alloy to prove the influence of the physisorption, and the results show that an increase in the hydrogen storage capacity was resulted in when sample loading decreases. After correction for this hydrogen physisorption, the capacity was restricted between 1.38 and 1.41 wt.%. Multi-walled carbon nanotubes (MWCNTs), activated carbon (AC), single-walled carbon nanotubes (SWCNTs), graphite nanofibers (GNFs), and graphite oxide (GO) were also measured and corrected through this method.     

Activation, characterization and hydrogen storage properties of the mesoporous carbon CMK-3

Activation of mesoporous carbon CMK-3 with CO₂ for hydrogen storage was studied. Huge structure and texture changes emerged for the activated CMK-3 based on the characterization by using XRD, TEM and nitrogen adsorption at 77 K. The ordered mesoporous structure of CMK-3 gradually became disorder and its specific surface area and volume of pores especially micropores were enhanced remarkably. Hydrogen sorption measurement showed that the activation led to an obvious increase of the H₂ sorption capacity of CMK-3. The maximum H₂ uptake of 2.27 wt% at 77 K and 1 bar was obtained for the sample activated at 1223 K for 8 h. The small pores with the diameter smaller than 1 nm contributed greatly to the H₂ uptake, and were confirmed more effective than other pores for hydrogen storage.     

介质阻挡放电等离子体处理载体对CO甲烷化Ni/SiO2催化剂性能的改进

以经介质阻挡放电等离子体处理的SiO₂为载体,用浸渍法制备了Ni/SiO₂催化剂,并进行了CO甲烷化反应评价。与载体未经处理的常规Ni/SiO₂催化剂相比,载体经处理的催化剂在400℃下的CO与H₂转化率均提高了约6%,且在经700℃烧结6 h后,活性仍高于常规催化剂。XRD、TEM和H₂-TPR结果表明,载体经处理的催化剂,Ni颗粒粒径更小、粒径分布更集中,Ni与SiO₂之间的相互作用更强,证明等离子体处理使SiO₂更有利于促进Ni的分散。     

Heterogeneously assisted oxidation of adsorbates from carbonmonoxide, methanol and ethanol by hydrogen peroxide solutions on platinum electrodes in sulphuric acid

The influence of hydrogen peroxide on the adsorption and oxidation of carbon monoxide, methanol and ethanol adlayers on porous Pt electrodes were studied in 2 M sulphuric acid solution by means of cyclic voltammetry and differential electrochemical mass spectrometry (DEMS). The oxidation of adsorbed species is observed at electrode potentials far less negative than those required for electrochemical adsorbate oxidation. The oxidation by H₂O₂ is dependent on its concentration in solution, as well as on the adsorbates and their coverages. In all cases the isolated adlayers are oxidised by dissolved H₂O₂. However, the presence of H₂O₂ during adsorption partially inhibits adlayer formation from CH₃OH and C₂H₅OH, but avoids almost completely the adsorption of carbon monoxide. The removal of the residues from the surface by dissolved hydrogen peroxide probably occurs through O_ad species formed during the heterogeneous decomposition reaction of H₂O₂ on Pt.     

Molten salt synthesis of nitrogen-doped porous carbons for hydrogen sulfide adsorptive removal

Nitrogen-doped porous carbons (NPCs) with high hydrogen sulfide (H₂S) adsorption capacity have been prepared through the molten-salt approach, using d-glucose as carbon source, melamine as nitrogen source and eutectic salt (LiCl/KCl) as porogen. The NPCs possess tunable nitrogen content (3.07–24.31 wt.%) and specific surface area (451–1190 m²/g) with the changing of the weight ratio of nitrogen source to carbon source and synthesis temperature. The H₂S adsorptive performance of NPCs is highly superior to that of non-doped porous carbon. X-rays photoelectron spectroscopy analyses combined with quantum chemical calculations demonstrate that the adsorption performance of the as-prepared NPCs depends on their nitrogen content and N-bonding configurations in the carbon materials, as well as their porosity. Pyridinic nitrogen doped carbon in NPCs have stronger interaction with H₂S compared to pyrrolic and graphitic nitrogen doped carbon. Based on the advantages of the developed porosity and abundant nitrogen functional groups, the saturated sorption capacities of 0.97–1.25 mmol H₂S/g can be achieved over NPCs at 25 °C under dry and anaerobic conditions.     

Preparation of Magnesium‐based Hydrogen Storage Materials and Their Effect on the Thermal Decomposition of Ammonium Perchlorate

Magnesium‐based hydrogen storage materials (MgH₂, Mg₂NiH₄, and Mg₂Cu‐H) were prepared and their structures were determined by XRD and ICP investigations. Mg₂NiH₄ has a monoclinic crystal structure and Mg₂Cu‐H is a mixture of MgCu₂ and MgH₂. The effects of magnesium‐based hydrogen storage materials on the thermal decomposition of ammonium perchlorate (AP) were studied by thermal analysis (DSC). It was found that magnesium‐based hydrogen storage materials show obvious boosting effects on the thermal decomposition of AP. The thermal decomposition peak temperature of AP was decreased, while the heat release of the decomposition of AP was increased. It was revealed that the effects of magnesium‐based hydrogen storage materials on the decomposition of AP become stronger with increasing content. The influence mechanism on the thermal decomposition of AP is suggested as follows: hydrogen released from magnesium‐based hydrogen storage materials and Mg, Ni, or Cu react with the decomposed products of AP.     

Post-synthesis modifications of SBA-15 carbon replicas: Improving hydrogen storage by increasing microporous volume

SBA-15 carbon replicas were synthesized with a sucrose solution as carbon source, carrying out carbonization at two different temperatures (800 and 1000 °C). Carbon pyrolised at 800 °C showed higher BET surface area and was chosen for further post-synthesis activation treatments (physical via CO₂ or chemical via KOH), with the aim of improving hydrogen adsorption capacity. For comparison, an amorphous carbon was also synthesized, by direct carbonization of the carbon source, without any inorganic template: on this material a chemical activation was also performed. H₂ adsorption isotherms at the temperature of liquid nitrogen and sub-atmospheric pressure were measured. A linear correlation was found between hydrogen uptake and microporous volume of the different carbons, rather than with BET specific surface area. Surprisingly, the sample prepared in the absence of inorganic template resulted the most effective one.