车载二甲醚重整制氢技术的研究进展

二甲醚是一种清洁燃料,有望取代传统汽车燃料以达到高效能低排放的目的。研究表明,在发动机中添加一定量氢气可有效提高二甲醚的燃烧性能,车载二甲醚重整制氢技术的研究迫在眉睫。本文总结和评述了二甲醚重整制氢技术的研究进展,包括二甲醚重整制氢的方法以及重整催化剂等,并简要分析了各种二甲醚重整方法应用于车载重整器的可能性,指出催化剂的新型制备方法与等离子体重整技术是今后二甲醚车载制氢的主要方向。     

甲烷部分氧化及重整反应多相催化剂的研究进展

介绍国内外甲烷制合成气技术中多相催化剂的研究进展,包括催化剂在水蒸气重整、甲烷部分氧化和二氧化碳重整制合成气技术中的研究情况,重点评述了催化剂的活性组分、助剂和载体方面的研究进展及存在的问题。     

燃料电池供氢系统研究进展

对燃料电池供氢系统的研究进展进行了综述,介绍了重整制氧方法、反应器类型以及富氧气体的各种净化技术.对比了蒸汽重整、部分氧化重整和自热重整3种制氢反应各自的特点,对不同反应器的研究结果及优缺点进行了分析.总结了富氢气体中CO的脱除工艺,包括选择性氧化、甲烷化、变压吸附和膜分离,其中CO选择性氧化相对其他方法更具优势.探讨了制氢过程中各种技术的特点和急需解决的问题,并对供氢系统的应用前景做了展望.     

甲烷为燃料的固体氧化物燃料电池阳极反应的研究进展

介绍了甲烷为燃料的固体氧化物燃料电池中不同类型的阳极反应,对直接电化学氧化、蒸汽重整、部分氧化、氧化耦合等阳极过程的反应特点、电性能和材料要求进行了重点评述,并指出了阳极积碳、反应机理、阳极过程热平衡等有待进一步探索的问题.     

燃料电池用柴油重整制氢技术现状与展望

现有储氢技术在储氢密度、能耗及相应的基础设施建设等方面存在明显短板，难以满足燃料电池技术商业化发展需求，现场制氢技术得到了广泛关注。其中，柴油重整制氢技术以其理论产氢比率高、适用领域广、基础设施完善、安全性好、成本低等优点，可广泛应用于汽车、船舶、分布式发电等民用领域以及潜艇、舰船等军事领域，成为热点研究之一。本文综述了柴油重整制氢的分类，详细介绍了蒸汽重整、部分氧化重整和自热重整制氢的反应机理，并对三种重整反应的优缺点进行了对比分析；在此基础上，概述了三种重整反应国内外研究现状。总体而言，蒸汽重整产物中氢气浓度最高但系统质量较大，比较适用于固定制氢领域；自热重整技术系统结构较为紧凑，产物氢气浓度适中，比较适用于汽车等移动制氢领域；部分氧化重整技术由于产物H₂/CO比率较低，加之反应温度较高，容易发生结焦反应，目前其应用领域还相对有限。     

甲醇制氢的燃料电池技术及应用

以质子交换膜燃料电池为例 ,介绍了甲醇蒸汽重整、甲醇分解以及甲醇部分氧化重整制氢为燃料电池提供燃料的催化反应机理、反应条件、催化剂性能等 ,并提出了甲醇制氢的质子交换膜燃料电池的优越性及应用前景。     

重整甲醇高温聚合物电解质膜燃料电池研究进展与展望

甲醇作为一种安全便捷的液态储氢燃料,具有高含氢量以及高体积能量密度,可经重整为富氢气后与燃料电池系统集成为重整甲醇高温聚合物电解质膜燃料电池,从而高效地将甲醇和氧气的化学能转变为电能。本文针对重整甲醇高温聚合物电解质膜燃料电池的不同类型（外置重整型和内置重整型）,分别对其系统集成的实现与发展进行了总结,并介绍了其现阶段在军用和民用方面的应用情况,同时指出了技术研究与应用存在的瓶颈,并对未来的研究方向进行了展望。未来提升重整甲醇高温聚合物电解质膜燃料电池性能的努力在于开发低温工作的高效甲醇重整催化剂,以及高温稳定运行的聚合物电解质膜和非贵金属材料等燃料电池关键材料。     

甲醇制氢的燃料电池技术及应用

以质子交换膜燃料电池为例介绍了燃料电池的工作原理、结构、性能等，简述了甲醇蒸汽重整、甲醇分解以及甲醇部分氧化重整制氢为燃料电池提供燃料的催化反应机理、反应条件、催化剂性能等，阐明从甲醇制氢的离子变换膜燃料电池的优越性及应用前景。     

甲醇制氢研究进展

介绍了制取氢气的常用原料。综述了用甲醇做原料制氢的研究进展,讨论了不同方式（裂化法、水蒸汽重整法、部分氧化法、自热重整法、等离子体法、电解法、超声波法）制氢技术的特点。目前甲醇气相重整技术较成熟,今后研究的重点是研制高效催化剂的制备、能量利用及氢气提纯方法。     

液体碳氢燃料蒸汽重整制氢催化剂研究进展

液体碳氢燃料具有能量密度高、氢含量大及便于储存和运输的特点,以其为原料经重整制氢并应用到移动式的燃料电池/加氢站对民用设备及国防武器等具有现实意义。本文首先对液体碳氢燃料蒸汽重整机理进行概述,明确当前催化剂面临的积炭、硫中毒等主要问题,从而指导高性能催化剂的设计和开发;其次,总结了几种典型液体碳氢燃料（汽油、煤油、柴油、焦油、含硫碳氢燃料等）蒸汽重整催化剂的相关进展,对比了不同催化剂在相应工艺条件下的活性及稳定性;最后,归纳了几类蒸汽重整过程强化技术包括等离子体重整、化学链重整、吸附增强重整及反应与分离耦合重整,说明了各类强化技术的优点及存在的不足,提出通过构建高效催化剂与蒸汽重整强化技术耦合有望实现液体碳氢燃料的高效转化制氢。希望本综述能为进一步研究液体碳氢燃料重整制氢提供相关指导。     

Catalytic aspects of the steam reforming of hydrocarbons in internal reforming fuel cells

Steam reforming of hydrocarbons such as natural gas is an attractive method of producing the hydrogen fuel gas required by fuel cells. It may be carried out external to the fuel cell or internally. The two types of fuel cell in which internal reforming is most appropriate are the molten carbonate (MCFC), operating at ca. 650°C and the solid oxide (SOFC) which currently operates above 800°C. At such temperatures, the heat liberated by the electrochemical reactions within the cell can be utilised by the endothermic steam reforming reaction. This paper reviews some of the catalytic aspects of internal reforming in these two types of cell. In the MCFC the major catalyst issue is that of long term activity in the presence of a corrosive alkaline environment produced by the cell's electrolyte. In Europe, this is being addressed by British Gas and others, in a programme part-funded by the European Commission. In this programme, potential catalysts for the direct internal reforming MCFC were evaluated in ‘out-of-cell’ tests. This has led to the demonstration of a 1 kW proof-of-concept DIR-MCFC stack and the start of a European ‘Advanced DIR-MCFC’ project. For the SOFC, it has been shown that state-of-the-art nickel cermet anodes can provide sufficient activity for steam reforming without the need for additional catalyst. However, anode degradation may occur when steam reforming is carried out for long periods. New anode materials could therefore offer significant benefits.     

液态生物质燃料重整及其在固体氧化物燃料电池中的应用

固体氧化物燃料电池（soild oxide fuel cell,SOFC）是一种清洁高效的发电装置,它可以利用氢气或碳氢燃料发电。液态生物质燃料是一种可再生碳氢燃料,它通过将生物质进行快速催化热解后,经过进一步催化加工制得,主要包括生物甲醇、生物乙醇、生物柴油及其副产物生物甘油等,将SOFC与液态生物质燃料结合,具有便携、清洁和高效等优点。本文分析了包括生物甲醇、生物乙醇、生物柴油以及生物甘油在内的液态生物质燃料的重整研究及其在SOFC中的应用进展,包括重整转化机理与效率、产物选择性、应用于发电存在的优势与难题等。通过对液态生物质燃料进行催化重整,可有效抑制SOFC直接使用液态生物质燃料发电存在的阳极积炭失活现象,从而提高发电效率,延长SOFC使用寿命。总结了目前液态生物质燃料直接用于SOFC发电的研究进展,提出了未来的研究方向,以期提高液态生物质燃料在SOFC中的利用效率和稳定性。     

Selection of appropriate fuel processor for biogas-fuelled SOFC system

The performance of biogas-fed solid oxide fuel cell (SOFC) systems utilizing different reforming agents (steam, air and combined air/steam) has been investigated via thermodynamic analysis to determine the most suitable feed. The boundary of carbon formation was first calculated to specify the minimum amount of each reforming agent necessary to avoid carbon formation. The SOFC performance (electrical efficiency and power density) was determined at different biogas compositions and reforming agent:biogas ratios. The SOFC performance is better when the methane content in the biogas is higher. Steam is considered to be the most suitable reforming agent in this study as the steam-fed SOFC offers much higher power density than the air-fed SOFC although its electrical efficiency is slightly lower. When steam is added in the air-fed SOFC as in the case of the co-fed SOFC, the power density can be improved but the electrical efficiency becomes lower compared with the case of the air-fed SOFC. Finally, in order to improve the electrical efficiency of the steam-fed SOFC, the biogas split option was proposed. It was found that a higher electrical efficiency can be achieved. In addition, although the power density is lowered by this operation, the value is still higher than the case of the air-fed SOFC.     

Modelling of an indirect internal reforming solid oxide fuel cell

Creation of an autothermal system by coupling an endothermic to an exothermic reaction demands the matching of the thermal requirements of the two reactions. The application under study is a solid oxide fuel cell (SOFC) with indirect internal reforming (IIR) of methane, whereby the endothermic steam reforming reaction is thermally coupled to the exothermic oxidation reactions. A steady-state model of an IIR-SOFC has been developed to study the mismatch between the thermal load associated with the rate of steam reforming at typical SOFC temperatures and the local amount of heat available from the fuel cell reactions. Results have shown a local cooling effect, undesirable for ceramic fuel cells, close to the reformer entrance. The system behaviour towards changes in catalyst activity, fuel inlet temperature, current density, and operating pressure has been studied. Increasing the operating pressure is shown to be an effective way of reducing both the local cooling caused by the reforming reactions and the overall temperature increase across the cell. Simulations for both counter-flow and co-flow configurations have been performed and compared.     

Effect of methane slippage on an indirect internal reforming solid oxide fuel cell

Creation of an autothermal system by coupling an endothermic to an exothermic reaction demands matching the thermal requirements of the two reactions. The application studied here is the operation of a solid oxide fuel cell (SOFC) with both direct (DIR) and indirect (IIR) internal reforming of methane. Such internal reforming within a high-temperature fuel cell module can lead to an overall autothermal operation which simplifies the system design and increases efficiency. However, such coupling is not easy to achieve because of the mismatch between the thermal load associated with the rate of steam reforming at typical SOFC temperatures and the local amount of heat available from the fuel cell reactions. Previous results have shown that the use of typical metal-based (e.g. Ni) IIR catalysts leads to full methane consumption but undesirable local cooling at the reformer entrance and the use of less active IIR catalysts (e.g. non-metals or diffusion limited nickel) leads to methane being carried-over into the SOFC anode (methane slippage). In order to evaluate performance in the latter case, a combined DIR and IIR SOFC steady-state model has been developed. Simulation results have shown that, lowering the IIR catalyst activity to prevent local cooling effects at the reformer entrance is not adequate, as the fast kinetics of the direct reforming reaction then lead to full methane conversion and steep temperature gradients in the first 10% of the fuel channel length. It is shown that the simultaneous reduction of the anode DIR reaction rate improves performance considerably. The system behaviour towards changes in current density, operating pressure, and flow configuration (counter-flow vs. co-flow) has been studied. Reduction of both DIR and IIR catalyst activity combined with a counter-flow operation leads to the best performance. System performance with an IIR oxide-based catalyst is also evaluated.     

Effect of precious metal addition to Ni-YSZ cermet on reforming of CH4 and electrochemical activity as SOFC anode

Various kinds of precious metals were added to the Ni-Y₂O₃-stabilized zirconia (Ni-YSZ) cermets, and the relation between steam reforming of CH₄ and the electrochemical activity as a solid oxide fuel cell (SOFC) anode was investigated. Ru and Pt additions promoted the reforming and suppressed the coke depositions. The electrochemical activity of the SOFC anode was enhanced by the addition of Ru and Pt, indicating that these precious metals effectively functioned as the anode catalysts. The impedance related to gas diffusion was greatly reduced, indicating that stability of the anode catalyst of SOFC was considerably improved since coke was hardly deposited.     

SOFC内部重整反应与电化学反应耦合机理

以经过预重整反应的混合气为原料的固体氧化物燃料电池（SOFC）内部,甲烷蒸气重整反应与电化学反应同时发生在阳极多孔介质中,二者受到不同的操作与设计参数的影响,对电池总体性能起着决定性作用。编制了三维数值模拟程序,对由多孔阳极层、气体流动管道、固体支撑平板构成的单个复合管道进行了研究。结果显示：重整反应主要发生在多孔材料靠近流动管道的薄层内,只有靠近管道入口处才能在较深处进行;电化学反应发生在多孔层与电解质的交界面处;重整反应生成的H2、CO扩散到多孔材料底部参加电化学反应;电化学反应生成的热量供重整反应使用。说明研究范围内,SOFC阳极复合通道具有较好的传热、传质性能,化学/电化学反应存在较好的耦合关系。     

Development of a novel test system for in situ catalytic, electrocatalytic and electrochemical studies of internal fuel reforming in solid oxide fuel cells

A test system based around a thin‐walled extruded solid electrolyte tubular reactor has been developed, which enables the fuel reforming catalysis and surface chemistry occurring within solid oxide fuel cells and the electrochemical performance of the fuel cell to be studied under genuine operating conditions. It permits simultaneous monitoring of the catalytic chemistry and the cell performance, allowing direct correlation between the fuel cell performance and the reforming characteristics of the anode, as well as enabling the influence of drawing current on the catalysis and surface reaction pathways to be studied. Temperature‐programmed reaction measurements can be carried out on anodes in an actual SOFC, and have been used to investigate the reduction characteristics of different anode formulations, methane activation and methane steam reforming, and to evaluate the nature and level of carbon deposition on the anode during reforming. This revised version was published online in July 2006 with corrections to the Cover Date.     

Investigation of a proton-conducting SOFC with internal autothermal reforming of methane

This study presents a performance analysis of a proton-conducting SOFC (SOFC-H⁺) with internal reforming of methane. The autothermal reforming within the SOFC-H⁺ stack is considered to be a potential solution of the carbon formation problem facing in operation of internal steam reforming SOFC-H⁺. A one-dimensional, steady-state model of the SOFC-H⁺ coupled with a detailed electrochemical model is employed to investigate its performance in terms of power density and fuel cell efficiency. The simulation results show that when SOFC-H⁺ is operated under an autothermal reforming environment, the presence of carbon monoxide, which is a major cause of carbon formation, in the fuel cell stack decreases. Effect of key operating parameters, such as temperature, steam-to-carbon and oxygen-to-carbon feed ratios, current density and fuel utilization, on the SOFC-H⁺ performance in terms of electrical efficiencies and energy demand is also investigated. The results indicate that operating temperatures have strong influence on SOFC-H⁺ performance, carbon monoxide production and heat generation.     

基于天然气自热重整的SOFC系统性能分析

建立一个天然气自热重整的固体氧化物燃料电池(SOFC)系统模型,利用Aspen Plus化工流程模拟软件链接基于Fortran语言编写的电堆模型,在质量守恒和能量守恒的基础上,分析不同参数对系统性能的影响。模拟结果表明:随着水碳比的增加,甲烷和一氧化碳的转化率增大,导致氢气和二氧化碳含量增加;氧碳比和系统效率在水碳比为1.5时达到最大。随着燃料利用率的增加,电流密度增大,导致空气过量系数增大,空气利用率降低;系统的总效率和净效率均随之增大。尾气温度随着水碳比和燃料利用率的增加均呈现下降趋势。系统的最大总效率和净效率分别为44.5%和39.2%。研究结果为进一步优化自热重整系统指明了方向。