我国生物质发电产业现状及建议

生物质发电是目前发展最成熟、规模最大的生物质能利用技术,通过利用生物质燃烧或转化技术实现可燃气体的燃烧发电。文章叙述了我国发展生物质发电产业的意义,概括和总结了国内外在生物质直燃发电、混燃发电和气化发电方面的现状和经验,指出我国生物质发电产业所面临的挑战,最后提出了有关生物质发电产业的商业化建议。     

生物质气化的应用与研究

生物质能是一种重要的可再生能源,利用生物质气化技术能实现CO2的减排,节约常规能源,符合可持续发展的要求.文章介绍了自1664年Thomas shirly进行气化试验以来,历经几百年的发展,生物质气化工艺和相关气化装置已经取得了巨大的进步;阐述了近几十年来我国在生物质气化领域的发展历程和取得的研究成果;对生物质的气化机理、气化装置结构,生物质气化技术的推广与应用、开发前景与经济效益进行了探讨.     

"林-菌-气"能源生态模式技术

“林-菌-气”能源生态模式就是结合食用菌产业发展的需要，在“林-菌”产业链中引人生物质气化技术，利用家用生物质气化炉这一能源设施，以废菌棒为气化原料生产生物质气低级气，代替木柴用于培养室产温、菌品烘干，菇农炊事等，用节约下来的木料生产食用菌，从而实现食用菌产业的持续、稳定发展的生产模式。     

生物质气化过程最小二乘支持向量机建模探讨

生物质气化过程的最终目标就是尽可能得到更多的高品质可燃气体,而目前的生物质气化过程还存在许多尚待解决的问题,例如气化温度、气化剂当量比、气化效率、燃气热值等参数优化问题.为此建立一种能适应生物质气化过程的模型,用于预测生物质气化气组分、热值、气化效率及碳转化率等指标,以及实现气化过程的参数优化都具有现实意义.本文在对生物质气化过程建模现状分析基础上,初步提出一种基于最小二乘支持向量机的气化过程建模方法,探讨了该方法用于生物质气化过程建模以及对气化过程主要参数进行优化的可行性.     

中国生物质气化发电技术的商业化分析

生物质气化发电技术是一种新型清洁发电技术,与传统火力发电技术相比,避免了CO2、SO2、NOx等有害气体的排放。“八五”、“九五”期间,科技部大力支持了生物质气化发电技术的研发工作和示范项目建设,取得了重要进展。但是,该技术的大规模推广最终必须依靠市场机制,实现商业化;而公共政策会在技术商业化过程中发挥重要的作用。该文简要介绍了生物质气化发电技术在我国发展的背景,研究了生物质气化技术的市场竞争力,分析了公共政策在生物质气化发电技术商业化过程中的作用。     

基于Gibbs自由能最小化原理模拟生物质流化床气化

基于能质平衡和吉布斯(Gibbs)自由能最小化原理,选择松木屑和麦秆两种生物质,利用化工商业化软件ASPEN PLUS模拟生物质流化床气化过程,并结合试验数据验证模拟结果的准确性。在此基础上考察了高温、原料含水率大范围变化等试验中较难实现的操作对气化的影响。模拟结果表明,搭建的气化模型能较好地模拟生物质气化过程,对生物质气化试验与工程放大具有一定的参考价值。     

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。     

浅谈生物质气化在发电技术应用

随着经济的发展,世界各国电力需求猛增,电力供应日益紧张,在这种环境下,通过气化发电技术,把生物质能转化为电能,既能大规模处理生物质废料,又能提供电力,具有明显的社会和经济效益。介绍了生物质气化发电技术的国内外发展现状,着重讲述了生物质气化发电技术的原理、特点和分类,以及各类生物质气化发电技术的特点,分析了生物质气化发电技术的社会效益及应用前景。指出在我国这样一个农业大国应该大力发展生物质气化发电技术。     

生物质气化影响因素分析

阐述了生物质定义、特点及生物质气化原理，综述了生物质在流化床气化中，气化剂、原料粒径、温度、压力、原料前处理等操作条件对生物质气化产品组成的影响，讨论了煤与生物质共气化的协同作用，指出了生物质流化床气化的技术关键。     

我国生物燃料技术开发成果

正我国生物燃料产业经过十几年的发展,已经形成十几条技术转化路线,生物质气化-合成油、生物质裂解提质油、EL类生物燃油、生物MTG油、CBGTL油、藻类油/燃气、生物质气化-合成天然气等各种新型生物燃料有望在今后几年商业化。用生物质原料制合成气,目前已开发出多系列达到示范工厂和商业应用规模的气化炉。采用气化-合成工艺生产生物天然气,可用木质类和干秸秆类原料,突破了微生物发酵法对原料的严格限制。     

Transesterification of marine macroalgae using microwave technology

Biodiesel is renewable and environmental friendly, with calori?c value equivalent to regular fossil fuel. This fuel can be produced from a variety of feedstocks, such as ?rst-generation biodiesel feedstock (corn, peanut, soybean), second generation (jatropha, animal fats, waste cooking oils, macroalgae), and third generation (microalgae). Among these feedstocks, biodiesel production from microalgae has drawn special attention for different reasons: they have high lipid content and high growth rates; they are tolerant to severe environmental conditions; they offer the possibility of sequester carbon dioxide from the ?ue gases; their harvesting and transportation are economical compared to other crops; and they have very high photosynthetic yields compared to other terrestrial plants. The advantage of using macroalgae recollected on the beaches as raw material is that allows to obtained energy from a residue.

Microwave-assisted extraction and transesteri?cation of microalgae is being researched as a solution for biodiesel production by its benefits, such as shorter reaction times and less amount of heat energy to obtain biodiesel. It is due to the fact that microwaves can easily penetrate through the cell wall structure to extract and transesterify the oils into biodiesel.

The aim of this research was to explore the possibility of carrying out the microwave-assisted transesterification of three marine macroalgae (brown and green). Different experimental runs were carried out with different process parameters such as macroalgae-to-methanol ratio, reaction time and catalyst concentrations. Based on the obtained results, the best conditions for microwave-assisted transesteri?cation reaction were macroalgae-to-methanol ratio of 1:15 (wt/vol), sodium hydroxide concentration of 2 wt% and reaction time of 3 min.     

第二代和第三代生物燃料发展现状及启示

第二代生物乙醇以生物质为原料,包括纤维素乙醇和纤维素生物汽油两种产品。目前已建有示范装置和/或工业装置的纤维素乙醇生产技术包括硫酸/酶水解-发酵技术、硫酸水解-发酵技术、酸水解-发酵-酯化-加氢技术、酶水解-发酵技术。业内专家认为,用酶替代硫酸水解是纤维素乙醇生产的发展方向。目前已经和准备进行示范装置试验的纤维素生物汽油生产技术包括快速热解-加氢改质技术和BioForming技术。第二代生物柴油主要以动植物油脂为原料,通过催化加氢生产非脂肪酸甲酯生物柴油,它是理想的优质柴油调合组分。生产第二代生物柴油的加氢技术包括加氢脱氧、回收丙烷和其他轻烃气体、脱水、异构化和裂化、蒸馏等5个步骤,主要有NExBTL可再生柴油生产技术、Ecofining绿色柴油生产技术、Haldor Topsoe可再生柴油生产技术、EERC可再生柴油生产技术。第三代生物燃料有两种:一种是以海藻油为原料生产乙醇、丁醇、喷气燃料和柴油,海藻培养(生长)和萃取海藻油是核心步骤,目前尚处于初期阶段;另一种是以生物质原料通过气化合成生产汽油、喷气燃料和柴油,重点是开发生物质气化技术,降低生产成本。我国应借鉴国外发展第二代和第三代生物燃料的做法,把技术开发工作做深做细做透,搞清楚原料的供应情况;目前我国生物柴油主要采用酯交换法生产脂肪酸甲酯,应考虑开发和采用加氢法生产第二代生物柴油,并努力扩大除麻风果油以外的原料来源;同时应加大海藻生物燃料和生物质气化合成生物燃料的开发力度。     

Review on dye-sensitized solar cells (DSSCs): Fundamental concepts and novel materials

The prosperity of human society largely relies on safe energy supply, and fossil fuel has been serving as the most reliable energy source. However, as a non-renewable energy source, the exhaustion of fossil fuel is inevitable and imminent in this century. To address this problem, renewable energy especially solar energy has attracted much attention, because it directly converts solar energy into electrical power leaving no environment affect. In the past, various photovoltaic devices like organic, inorganic, and hybrid solar cells were fabricated in succession. In spite of high conversion rate of silicon based solar cells, the high module cost and complicated production process restricted their application solely to astronautic and aeronautic technology. For domestic and other commercial applications, research has been focused on organic solar cells for their inherent low module cost and easy fabrication. In addition, organic solar cells have their lightweight and flexibility advantage over conventional silicon-based crystalline solar cells. Among all the organic solar cells, dye-sensitized solar cells (DSSCs) are the most efficient and easily implemented technology. Here, this study examines the working principle, present development and future prospectus for this novel technology.     

Reversible solid oxide cells applications to the building sector

Hydrogen can manage intermittent Renewable Energy Sources (RES), especially in high-RES share systems. The energy transition calls for mature, low cost, low space solutions bringing the attention to unitized items such as the reversible Solid Oxide Cell (rSOC). This device, made of a single unit, can work as an electrolyzer and as fuel cell with high efficiency, fuel flexibility and producing combined heat. The objective of this review is to identify and classify rSOC applications to the building sector as an effective solution and to show how much this technology is near to its commercialisation. Research & Development projects were analysed and discussed for a comprehensive overview. Conclusions show an increasing interest in the reversible technology, although it is still at pre industrialisation stage with few real applications in the building sector, of which, the majority is reported, commented, and compared in this paper for the first time.     

Modular biomass gasification-based solid oxide fuel cells (SOFC) for sustainable development

The integration of biomass gasification with SOFCs offers the potential of highly efficient and renewable power generation, primarily in modular solutions. SOFC seems to be the most promising fuel cell technology of biomass gasifier producer gases. Solid oxide fuel cells, because of their high operating temperature, do not require pure hydrogen as fuel, exhibiting high fuel flexibility. Sufficient amounts of cereal, cotton, corn, olive, coffee or palm tree residues are available in Mediterranean areas, while the climatic conditions are favorable for energy crops cultivations. Their residues can be utilized for electricity production by modular biomass gasification-based solid oxide fuel cells (SOFC).     

循环流化床锅炉磨损问题分析及防磨措施

循环流化床（CFB）锅炉作为一种洁净的发电技术,具有污染排放低、燃料适应性强等优点。磨损问题是困扰CFB锅炉技术发展的关键因素。本文通过对循环流化床锅炉磨损问题分析,详细剖析其产生原因及机理,并提出防磨措施。     

Hydrogen enrichment of methane and syngas for MILD combustion

Moderate or Intense Low-oxygen Dilution (MILD) combustion is a technology with important characteristics such as significant low emission and high-efficiency combustion. The hydrogen enrichment of conventional fuels is also of interest due to its favorable characteristics, such as low carbon-containing pollutants, high reaction intensity, high flammability, and thus fuel usage flexibility. In this study, the effects of adding hydrogen to methane and syngas fuels have been investigated under conditions of MILD combustion through numerical simulation of a well-set-up MILD burner. The Reynolds-Averaged Navier-Stokes (RANS) approach is adopted along the Eddy Dissipation Concept (EDC) combustion model with two different chemical mechanisms. Molecular diffusion is modeled using the differential diffusion approach. The effects of oxidizer dilution and fuel jet Reynolds number on the reactive flow field have been studied. Results show that with an increase in hydrogen portion of the fuel mixtures, the volume of the high-temperature region of combustion field increases whereas a reduction of oxidizer oxygen content leads to more proximity to the MILD condition. Increasing the fuel jet Reynolds number will result in an expansion of the combustion zone and shifting of this region in the axial direction. Predictions revealed that the methane flame is more sensitive to the oxidizer dilution and fuel jet Reynolds number than syngas. Moreover, enrichment of fuel with hydrogen seems to be better for acquiring condition of the MILD combustion for syngas rather than methane. Indeed, syngas shows more sensitivity to hydrogen enrichment than methane, which makes hydrogen a good additive to syngas in terms of MILD condition benefits.     

Direct ammonia solid-oxide fuel cells: A review of progress and prospects

With the rapidly declining cost of renewable energy, efficient ways are needed for its transportation between different regions. Hydrogen is becoming a major energy vector, with the key challenges of its storage and transportation commonly overcome by using ammonia for chemical storage of hydrogen energy. Ammonia, which is more energy dense than hydrogen and easier to transport, is a carbon-free alternative fuel that can be used in a variety of ways to generate power. Owing to their robustness and efficiency, solid-oxide fuel cells (SOFC) stand out as one of the most promising technologies that convert ammonia to electricity. Unlike other fuel cells, such as polymer electrolyte membranes, SOFCs do not require the fuel to be cleaned by energy-intensive external cracking and extensive cleaning; their high operating temperature provides the flexibility to crack the ammonia inside the anode or to use it directly. Here, we discuss experimental and numerical studies of ammonia SOFCs and critically review the status and opportunities for ammonia-fuelled SOFC technology. In the first section, we briefly outline the potential cathode and electrolyte materials for SOFCs. Only the anode component poses additional challenges with ammonia over the well-established hydrogen-fuelled SOFC technology, and this topic has been addressed in detail. Anode catalysts for ammonia decomposition, parameters affecting ammonia decomposition and anode catalyst degradation are also discussed. In the second section, we review the modelling studies for ammonia SOFCs. Finally, we run through the major commercial initiatives and demonstrations in green ammonia production and ammonia SOFCs.     

循环流化床锅炉水冷壁管束的磨损及预防

循环流化床燃烧技术是近二十年迅速发展起来的一种洁净煤燃烧技术.循环流化床锅炉具有煤种适应性强、燃烧效率高、污染物排放低和负荷调节性能好等优点,是目前推广应用的炉型之一.但是,由于炉内有大量的床料及循环物料,煤在物化状态下低温循环燃烧,造成烟气中含有大量的飞灰颗粒,这些灰粒高速冲刷水冷壁管、对流受热面等部位,使其壁面受到剧烈磨损,发生局部的严重破坏,甚至导致停炉事故.目前随着过热器和省煤器防护技术的成熟,磨损得到较好的控制,但是水冷壁管束的磨损控制还在摸索中.因此,了解飞灰磨损规律,找出主要磨损部位及原因,选择合理的防磨措施,进行合理的技术改造,保持锅炉最佳方式运行,使磨损损害减少到最小程度,无论从安全或经济上都是非常必要和及时的.     

燃油喷嘴小油量非线性区补偿算法研究

随着机动车排放标准的日趋严格和不断升级,汽油直喷(gasoline direct injection, GDI)发动机需要采用更加先进而复杂的喷射模式和控制策略才能满足其要求。而先进的喷射模式和控制策略则需要控制GDI喷油器在特性曲线非线性的小油量区域进行喷射,且各喷油器特性曲线之间的离散性很大。如果从机械设计或加工工艺上提高小油量喷射的一致性,则难度很大且成本很高。基于轨压降的小油量补偿策略,通过对补偿原理与方法进行深入的研究和试验分析,成功开发和实施了GDI喷油器小油量补偿策略,并在某量产GDI喷射器上进行了补偿效果的验证。试验结果表明,进行了油量补偿后的油量一致性有较大改善,满足了GDI喷油器的小油量喷射要求。