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。     

Fuel composition effects on transportation fuel cell reforming

This work examines the effect of various hydrocarbons on fuel processor light-off and reforming. Major hydrocarbon fuel constituents, such as aliphatic compounds, napthanes, and aromatics have been compared with the fuel processing performance of blended fuel components and reformulated gasoline to examine synergistic or detrimental effects the fuel components have in a real fuel blend.

Short chained aliphatic hydrocarbons tend to have favorable light-off and reforming characteristics for catalytic autothermal reforming compared with longer-chained and aromatic components. Oxygenated hydrocarbons have lower light-off requirements than do pure hydrocarbons. Gas phase oxidation favors higher cetane # fuels, which tend to be longer chained hydrocarbons. Energy consumption during the start-up process shows a large fuel effect. Methanol and dimethylether (DME) show lower start-up energy demands for the fuel processor start-up than do high temperature reforming hydrocarbon fuels such as methane, gasoline and ethanol. Aromatics and longer chained hydrocarbons show a higher tendency for carbon formation, increasing the amount of carbon formed during the light-off phase while the addition of oxygenates tends to lower the carbon formed during the start-up process.     

On-Board Hydrogen Generation for Fuel Cell-Powered Vehicles: The Use of Methanol and Propane

Although hydrogen has been found to be the most acceptable fuel for vehicle-mounted fuel cells, the storage and transportation of the gas presents difficulties. As a result, attention has been focused on on-board conversion of more readily available fuels such as methanol. Comparisons have been made of hydrogen generation from methanol and propane. Simulations are based both on thermodynamic and kinetic data. The results show that a mixture of oxidation and steam reforming (indirect partial oxidation) produces more hydrogen than direct partial oxidation. Propane is found to produce more hydrogen per weight carried than methanol, but suffers from the disadvantage that reaction does not start at room temperature. The necessity to fuel a vehicle with an organic fuel and with water is demonstrated.     

抗静电剂对碳氢燃料电导率的影响

在不同温度、浓度和贮存时间下测试添加抗静电剂T1502、STD450的3号喷气燃料、高环烷烃煤油、JP-10和加氧煤油4种碳氢燃料的电导率,以此考察抗静电剂对碳氢燃料电导率的影响.结果表明:碳氢燃料的电导率随温度升高而增大,随抗静电剂添加量的增大而增大,碳氢燃料的电导率受抗静电剂的离子性和碳氢燃料成分的舣重影响.同时实...     

Review: Microstructured reactors for distributed and renewable production of fuels and electrical energy

The current paper provides an overview of recent and past research activities in the field of microreactors for energy related topics. The main research efforts in this field are currently focussing on fuel processing as hydrogen source, mostly for distributed consumption through fuel cells. Catalyst development, reactor design and testing for reforming and removal of carbon monoxide through water-gas shift, preferential oxidation, selective methanation and membrane separation are therefore under investigation. An increasing number of integrated complete micro fuel processors has been developed for a large variety of fuels, assisted by static and dynamic simulation of these systems. The synthesis of liquid fuels is another emerging topic, namely Fischer-Tropsch synthesis, methanol and dimethylether production from synthesis gas and biodiesel production.     

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。     

Large-Scale Hydrogen Production

There is a growing need for hydrogen in processing heavier and dirtier fossil fuels and a future hydrogen economy is widely suggested as the next generation fuel/energy source once fossil fuels diminish in availability. Sustainable fuels are still regarded as too expensive given the large amounts of natural gas and a projected, ample supply of fossil fuels beyond the next twenty-plus years. Today, the steam reforming of hydrocarbons is the most favorable route to H₂. If CO₂ sequestration were ever to become widely practiced, fossil fuels would continue to play an important role in the future hydrogen economy.     

Novel Natural Gas to Liquids Processes: Process Synthesis and Global Optimization Strategies

An optimization‐based process synthesis framework is proposed for the conversion of natural gas to liquid transportation fuels. Natural gas conversion technologies including steam reforming, autothermal reforming, partial oxidation to methanol, and oxidative coupling to olefins are compared to determine the most economic processing pathway. Hydrocarbons are produced from Fischer–Tropsch (FT) conversion of syngas, ZSM‐5 catalytic conversion of methanol, or direct natural gas conversion. Multiple FT units with different temperatures, catalyst types, and hydrocarbon effluent compositions are investigated. Gasoline, diesel, and kerosene are generated through upgrading units involving carbon‐number fractionation or ZSM‐5 catalytic conversion. A powerful deterministic global optimization method is introduced to solve the mixed‐integer nonlinear optimization model that includes simultaneous heat, power, and water integration. Twenty‐four case studies are analyzed to determine the effect of refinery capacity, liquid fuel composition, and natural gas conversion technology on the overall system cost, the process material/energy balances, and the life cycle greenhouse gas emissions. © 2013 American Institute of Chemical Engineers AIChE J, 59: 505–531, 2013     

Thermodynamics on Landfill Gas Reforming

Landfill gas is a type of methane‐rich biogas which supplies renewable resources for clean fuels production. In this paper, the characteristics and optimum conditions of simulated landfill gas and biogas reforming reactions for H₂ production are investigated. The temperature, varied from 373.15 K to 1273.15 K, and pressure, varied from 1.013 bar to 40.013 bar, applied for the reforming system are evaluated. In addition, the effect of steam concentration, traces of hydrocarbons, and the ratio of C/H/O are analyzed using thermodynamic theories. Both the calculation and analyzed results demonstrate that the reforming system is primarily comprised of endothermic reactions. It favors lower pressure and higher temperature. Traces of hydrocarbons would result in a slight increase to CO for this system. A high ratio of CO₂ would result in more production of CO in the reforming process. Preliminary experiments on fuel cells indicate this gas‐reforming simulation is an elementary theory for fuel supply.     

Sustainable hydrogen production via reforming of ethylene glycol using a novel spouted bed reactor

Hydrogen produced from renewable energy sources is of great interest as an alternative to fossil fuels and as a means for clean power generation via fuel cells. The aqueous fraction of bio-oil can be effectively reformed to hydrogen rich streams in the presence of active catalytic materials. In this paper we present the experimental work carried out in a novel spouted bed reactor for the reforming of bio-oil. The use of a specially designed injection nozzle in combination with the particular hydrodynamic characteristics of the spouted bed resulted in efficient processing of the organic feed. The known problem of coking was notably avoided regardless of the loading material of the reactor. The effect of reaction temperature and steam to carbon ratio in the feed was investigated in the presence of various catalytic and non-catalytic particles. Runs were conducted with ethylene glycol as a representative model compound of the aqueous phase of bio-oil. Olivine, when associated with nickel, proved to be a very suitable catalytic material for the process combining high activity in reforming, anti-coking characteristics combined with exceptional mechanical strength.     

煤基燃料油品特性与煤制油产业发展分析

基于最新汽油、柴油和航煤质量标准,结合我国市场对成品油需求走向,本文探讨了煤直接液化油、煤间接液化油、加氢煤焦油、煤油共炼产品、甲醇制汽油（MTG汽油）和聚甲氧基二甲醚（DMM_n）等煤基油品的馏分结构与性质,分析了它们对煤制油产业发展的影响。文章指出国家绿色可持续发展需要低硫、低烯烃、低芳烃和高抗爆性能的交通运输燃料,需要降低柴汽比,增产航空煤油。煤基油品的硫氮等有害物质含量低、清洁性很好。除了MTG汽油外,煤基油品的柴汽比过高,需要与石油产品协同发展以满足我国未来的成品油市场需求。费托合成工艺能够直接生产优质柴油和航空喷气燃料油组分,是煤制油产业发展的主要技术路线;煤直接液化工艺所产汽煤柴油馏分性质均不理想,需要持续改进提高;煤油共炼工艺在成品油质量方面弥补了煤直接液化工艺的不足,可作为一条新的煤制油途径。煤焦油加氢可以生产出质量指标达到或接近国Ⅵ标准的车用柴油调和组分,是一条高效利用煤炭加工过程副产品的煤制油技术路线。MTG汽油和DMM_n是优质汽油和柴油组分,能改善炼油企业成品油的柴汽比结构和交通运输燃料产品质量,应加大低成本工艺技术研发、扩大产能。     

煤基/石油基火箭煤油高参数黏温特性与组分特性研究

为探究温度变化及组分变化对液体火箭推进剂黏度的影响规律,以煤基/石油基火箭煤油两种燃料为研究对象,获取两种燃料宽广温度和压力范围内的黏度数据,构建两种燃料“黏度-温度-压力”数学模型,大多数模型偏差都在5%的实验扩展不确定度范围内,能够精确预测燃料黏度随温度及压力的变化。黏温系数及等压黏度变化率的大小可反映不同燃料的黏温特性,对比结果表明,煤基煤油和石油基煤油的黏温系数和等压黏度变化率的绝对值相近,受温度影响程度几乎相同。根据运动黏度梯度,提供两种火箭煤油雾化燃烧效果最佳的临界预热温度。以灰色关联理论方法分析火箭煤油五组分烃类物质与黏度及黏度变化率的相关性,研究影响火箭煤油黏度的敏感组分因素。结果表明：单环烷烃对低温火箭煤油黏度指标影响最大,双环烷烃对高温火箭煤油黏度指标影响最大。     

Sorption enhanced steam reforming (SESR): a direct route towards efficient hydrogen production from biomass‐derived compounds

OVERVIEW: Efficient conversion of biomass to hydrogen is imperative in order to realize sustainable hydrogen production. Sorption enhanced steam reforming (SESR) is an emerging technology to produce high purity hydrogen directly from biomass‐derived oxygenates, by integrating steam reforming, water‐gas shift and CO₂ separation in one‐stage. Factors such as simplicity of the hydrogen production process, flexibility in feedstock, high hydrogen yield and low cost, make the SESR process attractive for biomass conversion to fuels. IMPACT: Recent work has demonstrated that SESR of biomass‐derived oxygenates has greater potential than conventional steam reforming for hydrogen production. The flexibility of SESR processes resides in the diversity of feedstocks, which can be gases (e.g. biogas, syngas from biomass gasification), liquids (e.g. bioethanol, glycerol, sugars or liquid wastes from biomass processing) and solids (e.g. lignocellulosic biomass). SESR can be developed to realize a simple biomass conversion process but with high energy efficiency. APPLICATIONS: Hydrogen production by SESR of biomass‐derived compounds can be integrated into existing oil refineries and bio‐refineries for hydrotreating processing, making the production of gasoline and diesel greener. Moreover, hydrogen from SESR can be directly fed to fuel cells for power generation. Copyright © 2012 Society of Chemical Industry     

Partial oxidation (POX) reforming of gasoline for fuel-cell powered vehicles applications

As a part of the development of a gasoline processor for integration with a proton-exchanged membrane (PEM) fuel cell, we carried out the POX reforming reaction ofiso-octane, toluene and gasoline over a commercial methane reforming catalyst, and investigated the reaction conditions required to prevent the formation of carbon and the effect of fuel constituents and sulfur impurities in gasoline. The H₂ and CO compositions increased with increasing reaction temperature, while those of CO₂ and CH₄ decreased. It is desirable to maintain an O/C molar ratio of more than 0.6 and an H₂O/C molar ratio of 1.5 to 2.0 for vehicle applications. It has been found that carbon formation in the POX reforming ofiso-octane occurs below 620 °C, whereas in the case of toluene it occurs below 640 °C. POX reforming of gasoline constituents led to the conclusion that hydrogen production is directly related to the constituents of fuels and the operating conditions. It was also found that the coke formation on the surface of catalysts is promoted by sulfur impurities in fuels. For the integration of a fuel processor with PEM fuel cell, studies are needed on the development of new high-performance transition metal-based catalysts with sulfur and coke-resistance and the desulfurization of fuels before applying the POX reformer based on gasoline feed.     

Syngas production from liquid fuels in a non-catalytic porous burner

This paper investigates rich combustion of n-heptane, diesel oil, kerosene and rapeseed-oil methyl ester (RME) bio-diesel for the purpose of producing syngas ready for the clean-up stages for fuel-cell applications or for traditional combustor enrichment. Rich flames have been stabilised in a two-layer inert porous medium combustor and a range of equivalence ratios and porous materials have been examined. n-heptane was successfully reformed up to an equivalence ratio of 3, reaching a conversion efficiency (based on the lower heating value of H₂ and CO over the fuel input) up to 75% for a packed bed of alumina beads. Similarly, diesel, kerosene and bio-diesel were reformed to syngas in a Zirconia foam burner with conversion efficiency over 60%. A preliminary attempt to reduce the content of CO and hydrocarbons in the reformate has been also conducted using commercial steam reforming and water-gas shift reaction catalysts, obtaining encouraging results. Finally, soot emission has been assessed, demonstrating particle formation for diesel oil above φ = 2, whereas bio-diesel showed the lowest soot formation tendency among all the fuels tested.     

On-board plasma-assisted conversion of heavy hydrocarbons into synthesis gas

The fuel conversion performance of two gliding arc plasma reformers is investigated with the goal of syn-gas production on-board vehicles. In both systems, n-tetradecane (C₁₄H₃₀) fuel was reformed with plasma under partial oxidation conditions in the absence of metal catalysts and steam. A comparison of the performance of each device is made with regard to the hydrogen yield and energy conversion efficiency. The results show that gliding arc systems are capable of reforming heavy hydrocarbon fuels with high conversion efficiency and are an important piece of technology for on-board vehicular reforming systems that should be further developed and optimized.     

Hydrogen production from liquid hydrocarbon fuels for PEMFC application

Lack of efficient hydrogen storage intermediate has boosted the development of fuel processor or economic onsite hydrogen production techniques for application to proton exchange membrane fuel cell promptly. Aiming to develop onsite hydrogen production techniques for proton exchange membrane fuel cell application using nickel-based reforming catalysts and stainless steel reactors, in this paper, a novel process for H₂ production from liquid hydrocarbon fuels was proposed and experimentally demonstrated on a lab scale. The main operations involved prereforming, autothermal reforming, high temperature water gas shift, low temperature water gas shift and H₂ enrichment by Pd membrane. The results indicated that prereforming introduction prior to autothermal reforming suppressed undesired gas phase reactions efficiently and made reforming reactions perform catalytically and smoothly, which was confirmed by a stable 500 h time-on-stream test of both prereforming and autothermal reforming catalysts. The air distributed feed applied in autothermal reforming reactor coupled the endothermic steam reforming and exothermic catalytic combustion reactions over the catalyst closely, maintaining an appropriate temperature distribution curve for autothermal reforming catalyst bed. During the process of H₂ enrichment by highly H₂ permeable Pd composite membrane, concentration polarization played an important role.     

Computational Studies for the Evaluation of Fuel Flexibility in Solid Oxide Fuel Cells: A Case with Biosyngas

The fuel flexibility of solid oxide fuel cells (SOFCs) is one of the advantages of this technology, and biosyngas produced from biomass is emerging as a new fuel. The fuelling of SOFCs with different fuels is always challenging because of the associated risks. Mathematical modeling tools are useful for predicting the operational safety constraints and designs of SOFCs that are suitable for different fuels. Using a single channel model that incorporates direct internal reforming (DIR), this work investigates the fuel flexibility of an anode‐supported intermediate temperature planar solid oxide fuel under co‐flow operation. The DIR reaction of methane, the water‐gas shift reaction (WGS) and the electrochemical reaction of hydrogen are the three reactions taken into account in this simulation work. Detailed comparisons of the gas concentrations, the current density distributions and the temperature change profiles are presented and discussed. These simulation results provide the initial data for performance analyses and safety predictions, which will be helpful for our future experimental investigations. The thermodynamic predictions of both nickel oxidation and carbon deposition are employed to check the operational safety of SOFCs fuelled with biosyngas.     

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。