生物质热解过程气体产物释放特性的研究

生物质热解是一种重要的热转化技术,同时也是生物质气化、燃烧与液化等热转化过程的初始阶段,因此生物质热解的研究具有很好的理论意义与应用前景。基于这样的背景,选用固定床反应器,以白松、花生壳和稻秸为生物质样品,对其慢速热解的各相产物、产率进行比较,然后对不同生物质的热解气体产物进行分析,最后深入考察碱金属催化剂(K2CO3)对于不同生物质催化裂解过程所产生的影响。结果表明,在相同慢速热解条件下,稻秸的制氢效果最为明显。在加入碱金属催化剂后,发现相较于白松和稻秸,K2CO3对于花生壳的催化制氢效果尤为显著。     

生物质热解液化技术研究与发展趋势

介绍了生物质热解液化技术,总结了该项技术在原料预处理、热解工艺和生物油分离精制3个方面的最新研究成果。在原料预处理方面,介绍了微波干燥、烘焙和酸洗3种方法;在热解工艺方面,介绍了催化热解和混合热解两种新工艺;在生物油分离精制方面,介绍了催化加氢、催化裂解、催化酯化、乳化燃油和分离提纯5种新技术,并分析展望了生物质热解液化技术的产业化发展趋势。     

生物油改性及催化热解技术研究进展

生物质快速热解制取生物油是一种生物质能源热转化的重要方式,是目前可再生能源利用研究的热点。文中介绍了快速热解技术的发展现状,详细讨论了生物质油的特性以及生物质油精制和改性方法,包括催化加氢、催化裂解、添加溶剂与乳化技术,以及近年来倍受关注的生物质催化热解技术。     

天然气裂解制氢的研究进展

综述天然气裂解制氢的研究进展,包括介绍催化裂解制氢、等离子体裂解制氢、等离子体催化制氢以及太阳能热解制氢等技术的特点及其国内外研究现状并进行比较分析,基于综述分析提出了相关研究重点。     

生物质流化床气化技术应用研究现状

按所得产品不同,可将生物质气化技术分为制氢、发电和合成液体燃料3大类。文章介绍了生物质流化床水蒸气气化制氢、催化气化制氢和超临界水气化制氢的工艺特点;分析了生物质流化床气化发电的技术、经济可行性;简述了生物质流化床气化合成液体燃料的研究现状;指出气化产出气化学当量比调变、焦油去除问题和合成气净化是生物质流化床气化技术应用的主要瓶颈,认为定向气化是今后研究的主要方向。     

生物质催化热解研究进展

介绍了生物质种类、生物油性质、热解反应条件对生物油产率和油品质的作用以及催化剂对催化热解反应的影响。生物质催化热解技术能够实现资源、能源、环境的高效统一,符舍社会的可持续发展原则,具有很大的开发前景。     

生物质超临界水催化气化制氢实验系统

生物质超临界水催化气化制氢是一项很有价值的离新技术，它有利于开发广泛的生物质资源，为大规模的制氢提供一条高效、清洁的途径。针对生物质超临界水气化制氢，国内外结合工作具体要求和条件，设计出了一系列生物质超临界水催化气化制氢的实验系统。主要对国内外几种较好的生物质超临界水催化气化制氢实验进行了综合评述，分析了各类实验系统存在的问题及待改进之处。     

生物质热解气化制取氢气

该文对生物质的热化学方法(主要是气化和热解)制取氢气进行了归纳总结，在此基础上研究了用热解方法从生物质原料中制取氢气的技术路线并介绍了催化制氢的实验室研究结果。研究的结果表明：催化剂的添加对热解过程的最终产品气及富氢气体的产率有影响；催化剂的负荷量对富氢气体的产率有显著影响，其值存在一个优化范围；同样的催化剂对稻杆和锯末热解获得的富氢气体的产率影响不同。     

生物质气化制氢研究现状

重点讨论生物质催化气化制氢的基本原理和基本过程，阐述生物质催化气化制氢、超临界水中生物质催化气化制氢、等离子体热解气化制氢的研究现状，指出生物质气化制氢的广阔前景。     

国外可再生能源文献信息

GW040401生物质制氢.BROWNKENNETH.BioCy-cle200445(1):54-55.生物质制氢具有很大的发展潜力。尽管生物质制氢的原料是廉价的废弃物,有很大的成本竞争空间,但是目前生物质制氢仍比天然气制氢的费用高。文章介绍了生物质制氢的生物转化技术和热化学转化技术的现状。GW040402生物质加压流化床气化器.HENRICHE,WEIRICHF.EnvironmentalEngineeringScience200421(1):53-64.提出了一个木质纤维素生物质干燥气化的新概念。对农业生物质原料秸秆的加工兼容性问题给予了特别的关注。农业生物质原料的灰分、钾、氯的含量比木材高,灰分…     

Hydrogen use—transportation fuel

The possibilities and limits of hydrogen for ground transportation are discussed. The state of development of the hydrogen infrastructure, of hydrogen storage means and of hydrogen drive systems including fuel cells are shown. The technical problems and their solutions in connection with metal hydride storage tanks in vehicles and the Daimler-Benz hydride vehicle program are described.     

A new hybrid fuzzy multi-criteria decision methodology model for prioritizing the alternatives of the hydrogen bus development: A case study from Romania

The aim of this study is to present an integrated multi-criteria decision making (MCDM) model for the selection method of hydrogen bus development by considering five main and twenty sub-criteria. The model utilizes Best-Worst Method (BWM) and MARCOS (Measurement Alternatives and Ranking according to COpromise Solution) approaches for prioritizing the alternatives of the appropriate hydrogen solution for public transport with buses. A case study in Romania verifies the applicability and effectiveness of the proposed model. A comparative analysis with some existing methods are presented to verify the superiority of the proposed model. This study analyzes two technical solutions for hydrogen production and refuelling infrastructure of fleet, and four electricity supply solutions for obtaining hydrogen by electrolysis. That means a total number of 8 alternatives. The results show that co-generated electricity from a municipality cogeneration power plant (Alternative 2) is the best alternative among eight alternatives.     

Enhanced rate of hydrogen production by corrosion of commercial aluminum

Hydrogen has been produced by corrosion of technical grade aluminum Al-6061. Al-6061 is an alloy containing a small percentage of several elements, mainly Mg and Si. It has been verified that this alloy is corroded faster and produces more hydrogen per unit of time than pure aluminum. This result is due to facilitation of corrosion at grain boundaries in aluminum alloys. Hydrogen production rates have been dramatically accelerated by decreasing the size of aluminum particles. Thus Al-6061 turnings have been produced with a lathe and then they were compressed to create porous pellets with a density of 72% compared to solid pure aluminum. These pellets can produce hydrogen in concentrated KOH solutions at very high rates reaching 66.7 ml min⁻¹. This method is safe and reproducible and it may find important application as a means to “store” hydrogen in the form of porous Al-6061 pellets.     

Economic competitiveness of compact steam methane reforming technology for on-site hydrogen supply: A Foshan case study

On-site hydrogen production through steam-methane reforming (SMR) from city gas or natural gas is believed to be a cost-effective way for hydrogen-based infrastructure due to high cost of hydrogen transportation. In recent years, there have been a lot of on-site hydrogen fueling stations under design or construction in China. This study introduces current developments and technology prospects of skid-mounted SMR hydrogen generator. Also, technical solutions and economic analysis are discussed based on China's first on-site hydrogen fueling station project in Foshan. The cost of hydrogen product from skid-mounted SMR hydrogen generator is about 23 CNY/kg with 3.24 CNY/Nm³ natural gas. If hydrogen price is 60 CNY/kg, IRR of on-site hydrogen fueling station project reaches to 10.8%. While natural gas price fall to 2.3 CNY/Nm³, the hydrogen cost can be reduced to 18 CNY/kg, and IRR can be raised to 13.1%. The conclusion is that skid-mounted SMR technology has matured and is developing towards more compact and intelligent design, and will be a promising way for hydrogen fueling infrastructures in near future.     

Tech-eco Efficiency Evaluation of hydrogen production industry under carbon dioxide Emissions regulation in China

This study introduces the concept of non-separable variables, and conducts a super-efficiency slack-based measure (SBM) model considered undesirable output variable to evaluate the economic and technical efficiencies of 15 hydrogen production methods in China. The results show that the average technical efficiency and scale efficiency values of hydrogen production industry are 0.438 and 0.352, respectively, which are relevantly low. The average pure technical efficiency value is 1.090. When the strong carbon constraint is introduced, the average technical efficiency and pure technical efficiency values of hydrogen production industry are increased by about 12.3% and 22.2%, respectively, but the average scale efficiency is reduced by 1.7%. The coal-to-hydrogen production with carbon capture, utilization and storage (CCUS) technology produces the highest technical efficiency, and the technical efficiency value and pure technical efficiency value are 1.435 and 1.679, respectively. The scale efficiency value of hydrogen production from chlor-alkali is 0.951, which is the most effective scale among all measured hydrogen production processes. The methanol-to-hydrogen production also performs great. However, hydrogen production by water electrolysis does not have the advantages of economic nor technical efficiencies. The results of the input-output slack of 15 hydrogen production methods show that the excessive production inputs and carbon dioxide emission are the main reasons for the poor efficiency evaluation results of most hydrogen production methods. The CO₂ emission regulation reduces the redundancy of the cost, comprehensive energy consumption and CO₂ emissions of 13 hydrogen production processes by more than four times, which affected the technical efficiency and the scale efficiency of hydrogen production industry. It indicates that CO₂ emission regulation has improved the economic and technical efficiency of hydrogen production processes in China.     

Review and comparison of worldwide hydrogen activities in the rail sector with special focus on on-board storage and refueling technologies

This paper investigates hydrogen storage and refueling technologies that were used in rail vehicles over the past 20 years as well as planned activities as part of demonstration projects or feasibility studies. Presented are details of the currently available technology and its vehicle integration, market availability as well as standardization and research and development activities. A total of 80 international studies, corporate announcements as well as vehicle and refueling demonstration projects were evaluated with regard to storage and refueling technology, pressure level, hydrogen amount and installation concepts inside rolling stock. Furthermore, current hydrogen storage systems of worldwide manufacturers were analyzed in terms of technical data.We found that large fleets of hydrogen-fueled passenger railcars are currently being commissioned or are about to enter service along with many more vehicles on order worldwide. 35 MPa compressed gaseous storage system technology currently dominates in implementation projects. In terms of hydrogen storage requirements for railcars, sufficient energy content and range are not a major barrier at present (assuming enough installation space is available). For this reason, also hydrogen refueling stations required for 35 MPa vehicle operation are currently being set up worldwide.A wide variety of hydrogen demonstration and retrofit projects are currently underway for freight locomotive applications around the world, in addition to completed and ongoing feasibility studies. Up to now, no prevailing hydrogen storage technology emerged, especially because line-haul locomotives are required to carry significantly more energy than passenger trains. The 35 MPa compressed storage systems commonly used in passenger trains offer too little energy density for mainline locomotive operation - alternative storage technologies are not yet established. Energy tender solutions could be an option to increase hydrogen storage capacity here.     

Smart energy solutions with hydrogen options

We are in an era where everything is now requested to be smart. Here are some examples, such as smart materials smart devices, smartphones, smart grid, and smart metering. In regard to energy portfolio, we need to make it in line with these under smart energy solutions. With the developed cutting-edge technologies and artificial intelligence applications, we need to change the course of action in dealing with energy matters by covering the entire energy spectrum under five categories, namely, energy fundamentals and concepts, energy materials, energy production, energy conversion, and energy management. It is important to highlight the importance of a recent event. On 17 January 2017 a total of thirteen leading energy, transport and industry companies in the World Economic Forum in Davos (Switzerland) have launched a global initiative, so-called: Hydrogen Council, to voice a united vision and long-term ambition for hydrogen to foster the energy transition. It has aimed to join the global efforts in promoting hydrogen to help meet climate goals. This is a clear indication that smart solutions are not possible without hydrogen options. This study focuses on introducing and highlighting smart energy solutions under the portfolio pertaining to exergization, greenization, renewabilization, hydrogenization, integration, multigeneration, storagization, and intelligization. Each one of these plays a critical role within the smart energy portfolio and becomes key for a more sustainable future. This study also focuses on the newly developed smart energy systems by combining both renewable energy sources and hydrogen energy systems to provide more efficient, more cost-effective, more environmentally benign and more sustainable solutions for implementation. Furthermore, a wide range of integrated systems is presented to illustrate the feasibility and importance such a coupling to overcome several technical issues. Moreover, numerous studies from the recent literature are presented to highlight the importance of sustainable hydrogen production methods for a carbon-free economy.     

Boron‐based hydrides for chemical hydrogen storage

The development of the hydrogen economy is hampered by many issues connected with production, storage, distribution, and end‐use. Although the hydrogen storage problem is particularly difficult, there are several attractive solutions under investigation, and chemical hydrogen storage (involving hydrogen‐rich materials) has shown much promising properties. The boron‐based materials are typical examples. They have high hydrogen densities, with up to four reactive B ? H bonds. Most of the works have focused on dehydrogenation by hydrolysis or thermolysis so that it takes place in high extent in mild conditions. The first materials studied have been lithium borohydride, sodium borohydride, and ammonia borane. However, their development has been hindered by technical issues such as very high dehydrogenation temperatures, incomplete reaction, and purity of the produced hydrogen. To get round such problems, new materials have been proposed since the mid‐2000s. Interestingly, those materials present attractive attributes, but also drawbacks. This is illustrated in the present review. We believe that boron‐based hydrides have a significant potential in chemical hydrogen storage, but their implementation depends on the recyclability of the solid by‐products; this seems to be the key factor. Copyright © 2013 John Wiley & Sons, Ltd.     

太阳能制氢关键技术研究

围绕太阳能制氢技术展开论述,首先,介绍太阳能制氢技术的研究现状;其次,对于太阳能制氢技术尤其是光催化制氢技术及热化学循环分解水制氢技术,分别从技术原理、关键材料、技术难点等方面进行详细的论述;最后,对太阳能制氢技术研究给出结论及建议,旨在为未来太阳能制氢技术的研发布局和产业技术突破提供参考和思路。