生物质热化学液化技术研究进展

随着化石燃料可开采量的减少和人类对全球性环境问题的关注，生物质作为一种可再生能源，由于资源丰富，分布广泛，燃烧过程对环境的低污染性，CO2的净零排放等特性日益成为国内外众多学者研究的热点课题之一。生物质转化技术可分为生物法和热化学转化法，后者主要有气化、热解、高压液化及与煤共处理等工艺。其中生物质热化学液化由于比气化能得到更有价值的液体产物，操作温度比热解低，因而作为一项资源高效利用的新工艺日益受到重视。综述了近五年来生物质热化学液化技术方面的最新进展，提出了今后的研究动态与发展方向，并针对我国现状提出应采取的对策。     

太阳能制氢技术

近几年来，随着质子交换膜氢燃料电池技术获得前所未有的进展，氢燃料电池被视为最具潜力的环保汽车动力源，逐步走向商品化。氢燃料电池是利用氢和氧（或空气）直接经电化学反应产生电能。氢也可以直接燃烧放热。氢的热值（１４２０００kJ／kg）是石油热值（４８０００kJ／kg）的３倍。而且，氢的燃烧产物主要是水，具有无污染、无毒等环保优势，是矿物燃料无法比拟的。此外，科学家研究表明，在石油中加入５％的氢，可提高效率２０％，并减少９０％的致癌物；若用管道传送氢气到五六百公里外，要比电线输送同等能量的电力便宜九成。科学…     

制氢技术和工艺

氢能是最具希望的能源之一，氢能的获得在于制氢原料和制氢途径两大因素。文章详细介绍了目前制氢技术和工艺的发展现状，并根据我国国情提出了利用生物质制氢的能源利用新方式。     

生物质热化学过程制氢技术

生物质是世界上最丰富的可再生资源之一,氢能源是未来理想的能源载体.生物质生长周期短,产量巨大,作为能源利用时,其CO2排放量几乎为零,因此被视为非常有潜力的清洁能源之一.生物质制氢技术主要包括热化学过程和生物过程,其中热化学过程主要是将生物质气化或生成生物油,再进行重整和水气置换反应,从而获得较高产量的氢气.文章介绍了利用生物质热裂解和气化(包括超临界水条件下气化)制氢技术,并对其未来的发展做了展望.     

几种生物质制氢方式的探讨

生物质资源丰富，是一种重要的可再生能源而且其自身是氢的载体；与矿物燃料相比，具有挥发分高，硫、氮含量低等优点，无论是从能源角度还是从环境角度，发展生物质制氢技术都具有重要的意义。文章论述了生物质制氢的各种方式，介绍了各自的优缺点及面临的困难，着重论述了生物质热化学转换方式制氢，并对其未来的应用前景做了一定的预测。     

生物质热化学转化过程中碱金属分布及迁移特性

生物质能源具有分布广泛,总量巨大,H/C比高的优点。对其充分利用可有效缓解当下的化石能源危机,还可以为“碳达峰”及“碳中和”目标做贡献。但在其综合利用过程中,其中含有的碱金属元素会带来诸多问题,严重制约生物质热化学转化利用的发展。主要综述生物质热化学转化过程中碱金属的迁移特性,对生物质热转化中碱金属分析理论技术、生物质中碱金属含量及赋存形态、碱金属迁移转化影响因素进行论述,并对生物质内碱金属元素的赋存形态区分、碱金属释放的原位检测技术以及碱金属迁移转化过程中各反应之间竞争及促进作用进行总结和展望。     

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。     

基于热化学平衡的生物质气化过程建模

生物质气化是生物质能利用的主要形式之一。通过对生物质气化过程的分析,建立了一种基于热化学平衡机理的气化过程平衡模型。详细介绍了模型的原理、建立过程以及模型的求解和验证。计算结果表明,模型能够对生物质的气化过程中的反应特性起到预测作用,为今后生物质气化过程的参数优化和控制计算提供了一定的理论依据。     

Uranium thermochemical cycle: hydrogen production demonstration

In hydrogen production industry, thermochemical cycle technology for converting thermal energy into chemical storage energy of hydrogen owns absolute advantages. Compared with other thermochemical cycles, thermochemical cycle technology based on uranium (UTC) is safer and more efficient. This technology consists of three steps, where only the hydrogen production step is unique. In this paper, the verification has been done for this step. Solid products were characterized by XRD and Raman spectroscopy, which were confirmed to be α-Na₂U₂O₇. Gas chromatographic analyses were performed for gas samples, in which hydrogen output was obtained using an internal standard method.     

太阳能热化学制氢技术研究进展

总结了目前国内外太阳能制氢方法的研究现状,经过分析比较,确定太阳能热化学制氢具有极大的潜在发展空间.同时详细介绍了该方法的最新进展,对该方法研究中存在的问题提出了合理的改进建议.     

A review on integrated thermochemical hydrogen production from water

Hydrogen production from water splitting is considered one of the most environmentally friendly processes for replacing fossil fuels. Among the various technologies to produce hydrogen from water splitting, thermochemical cycles using chemical reagents have the advantage of scale up compared to other specific facilities or geological conditions required. According to thermochemical processes using chemical redox reactions, 2-, 3-, 4-step thermochemical water splitting cycles can generate hydrogen more efficiently due to reducing temperatures. Increasing the number of cycles or steps of thermochemical hydrogen production could reduce the required maximum temperature of the facility. In addition, recently developed hybrid thermochemical processes combined with electricity or solar energy have been studied on a large scale because of the reduced cost of hydrogen production. Additionally, hybrid thermochemical water splitting combined with renewable energy can result in not only reducing the cost, but also increasing hydrogen production efficiency in terms of energy. As for a green energy, hydrogen production from water splitting using sustainable and renewable energy is significant to protect biological environment and human health. Additionally, hybrid thermochemical water splitting is conducive to large scale hydrogen production. This paper reviews the multi-step and highly developed hybrid thermochemical technologies to produce hydrogen from water splitting based on recently published literature to understand current research achievements.     

超临界水中生物质气化制氢的反应路径

超临界水中生物质气化制氢技术因其具有良好的环保性、产氢高等特点已成为氢能领域的研究热点之一。文中对超临界水中生物质气化制氢反应路径的研究结果进行了总结，归纳了生物质及其模型化合物葡萄糖在亚临界和超临界水中分解气化的可能的反应路径以及反应过程中产生的一系列中间产物，讨论了影响反应的主要因素。     

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。     

A review on biomass‐based hydrogen production and potential applications

In this paper, a detailed review is presented to discuss biomass‐based hydrogen production systems and their applications. Some optimum hydrogen production and operating conditions are studied through a comprehensive sensitivity analysis on the hydrogen yield from steam biomass gasification. In addition, a hybrid system, which combines a biomass‐based hydrogen production system and a solid oxide fuel cell unit is considered for performance assessment. A comparative thermodynamic study also is undertaken to investigate various operational aspects through energy and exergy efficiencies. The results of this study show that there are various key parameters affecting the hydrogen production process and system performance. They also indicate that it is possible to increase the hydrogen yield from 70 to 107 g H₂ per kg of sawdust wood. By studying the energy and exergy efficiencies, the performance assessment shows the potential to produce hydrogen from steam biomass gasification. The study further reveals a strong potential of this system as it utilizes steam biomass gasification for hydrogen production. To evaluate the system performance, the efficiencies are calculated at particular pressures, temperatures, current densities, and fuel utilization factors. It is found that there is a strong potential in the gasification temperature range 1023–1423 K to increase energy efficiency with a hydrogen yield from 45 to 55% and the exergy efficiency with hydrogen yield from 22 to 32%, respectively, whereas the exergy efficiency of electricity production decreases from 56 to 49.4%. Hydrogen production by steam sawdust gasification appears to be an ultimate option for hydrogen production based on the parametric studies and performance assessments that were carried out through energy and exergy efficiencies. Finally, the system integration is an attractive option for better performance. Copyright © 2012 John Wiley & Sons, Ltd.     

Preliminary results of the integrated hydrolysis reactor in the Cu-Cl hydrogen production cycle

This paper presents preliminary results of an integrated hydrolysis reactor at the Clean Energy Research Laboratory (CERL), University of Ontario Institute of Technology. Initial tests have demonstrated a successful reactor design allowing for effective recovery of liquid products. Using our best available performance metrics, the conversion rate of reagents to products ranged from 7% to 10%. Initial experimental runs demonstrated that the reactor was successfully operational with combined H₂O and reagent injection in a configuration suitable for integration with the electrolysis step of the Copper-Chlorine loop. In this paper, we discuss the updated hydrolysis reactor design and present data from a number of recent experiments in which our research team recovered solids and chemical products not previously collected in prior studies. Comparisons were made with earlier XRD data taken at the Argonne National Laboratory. The comparisons showed promising results in the chemical composition of the solids produced. We conclude this paper with a discussion of future experiments to increase the conversion rate of reaction based on the observed trends.     

Value analysis for commercialization of fermentative hydrogen production from biomass

In addition to producing hydrogen gas, biohydrogen production is also used to process wastewater. Therefore, this study specifically conducted value analyses of two different scenarios of fermentative hydrogen production from a biomass system: to increase the value of a wastewater treatment system and to specifically carry out hydrogen production. The analytical results showed that fermentative hydrogen production from a biomass system would increase the value of a wastewater treatment system and make its commercialization more feasible. In contrast, fermentative hydrogen production from a biomass system designed specifically for producing hydrogen gas would have a lower system value, which indicated that it is not yet ready for commercialization. The main obstacle to be overcome in promoting biohydrogen production technology and system application is the lack of sales channels for the system's products such as hydrogen gas and electricity. Thus, in order to realize its commercialization, this paper suggests that governments provide investment subsidies for the use of biohydrogen production technology and establish a buy-back tariff system for fuel cells.