生物质液化技术面临的挑战与技术选择

生物质液化技术可将低品位的固体生物质完全转化成高品位的液体燃料或化学品,是生物质能高效利用的主要方式之一。按照机理,液化技术可以分为热化学法、生化法、酯化法和化学合成法(间接液化),热化学法液化又分为快速热解技术和高压液化(直接液化)技术。生物质热化学法液化已成为国内外生物质液化的研究开发重点和热点,快速热解液化技术和高压液化技术是最具产业化前景的生物质能技术,生化法液化技术也是生物质能的研究热点。化学合成法液化技术并不适用于生物质液化,而利用生物柴油进一步生产生物航空煤油是得不偿失的,不仅成本高、资源利用率低,而且全生命周期碳排放增加,还不符合未来生物航煤的发展趋势。生物质含水量的高低是影响生物质液化过程中能耗、效率、污染指数和经济性指标等的关键因素,应根据含水量合理选择生物质液化技术。快速热解液化技术适用于低含水农林废弃物,高压液化和生化法液化技术适用于高含水生物质,酯化法液化技术适用于不可食用油脂,而各种液化技术均不适用于城市生活垃圾的处理,建议将其用作燃气型气化原料。     

生物质能的应用前景分析

生物质能是可再生能源的重要组成部分，生物质能的高效利用，对解决能源和生态环境问题将起到十分积极的作用。概述了目前生物质能的主要转换方式。化学转变中的液化、气化和热解技术是目前主要研究方向。通过液化、热解可以直接得到一些化工产品；通过气化可以得到合成气，可以用来合成氨或者甲醇。总之，通过这些转变不但可以得到一些化工产品，而且可以缓解化石能源桔竭带来的能源危机。     

生物质能转化技术及资源综合开发利用研究

开发利用生物质能源,对保障国家能源安全、实现节能减排战略目标意义重大。我国生物质能的开发利用技术取得了许多优秀成果,但与发达国家相比,还存在不少差距。生物质资源可分为林业资源、农业资源、生活污水和工业有机废水、城市固体废物、禽畜粪便等,其化学组成和化学结构也差异很大。生物质能的转化技术方式主要为:直接燃烧方式,物化转换方式,生化转化技术,化学转化方式。面对传统能源的市场竞争,我国生物质能源开发只有依靠科技进步,将生物质能资源进行精细化工产品的深度利用,综合开发,使之增值,反哺生物柴油、燃料乙醇及生物质燃气等能源产品的开发;利用现代转基因技术培育能源植物新品种,提高出油率,降低原料成本;创新生物质能转化技术,提高生物质能产品产量、降低生产成本。运用精细化工技术平台开发生物质资源,已成为生物质资源综合利用领域的研发热点。在生产生物质能源产品的同时,综合开发利用生物质资源,将成为未来世界新的经济增长点。     

欧美国家重视发展生物质能

生物质能是指可提供能源的有机物，如农业废物、家畜排泄物和有机垃圾等，将这些有机物直燃或高温化发酵后可产出甲烷、甲醇、甲酯等，用于发电或汽车燃料。由于它们生长过程中可吸收二氧化碳，又利于废物利用，故欧美国家多将其作为可再生能源大力发展。 欧盟规划2010年可再生能源比达12%，每年可替代2000万t石油，其中80%为成本较低的生物质能。瑞典对废木材的利用十分重视，生物质比已达20%。法国将生物质能甲酯化后和柴油并用以替代石油。美国规划2010年生物制品及生物质的产量为现在的3倍，生物质能比达10%，主要利用废木材发电，利用…     

甜高粱--高效率的太阳能转化器

生物质能是通过植物的光合作用将太阳能转化储存而形成的。而植物的光合作用被认为是最有效的、最经济的固定太阳能的方式，而且这种能量转化与储存很方便，是由生长的植物体或生物质来完成。     

生物质能发电技术分析

在不可再生能源濒临枯竭,环境污染日益加剧的今天,生物质能源替代化石能源利用的研究和开发,已成为国内外学者研究和关注的热点。介绍了国内外生物质能的主要转化利用技术,分析了生物质直接燃烧发电技术和气化发电技术,提出了符合能量梯级利用原则的生物质能发电方式,将是生物质能利用的主要形式。     

开发生物质能源提高环境质量

太阳能、生物质能等无污染能源、可再生能源的开发是一项重要工作。生物质能源能够就地开发利用，价格比较低，利用比较方便。生物质能的开发在我国起步较晚，近几年的研究，已经取得了较为明显的效果，其利用方式也越来越多。     

在燃煤电厂利用生物质再燃还原氮氧化物

生物质能是一种可再生的清洁能源,利用生物质能基本可以实现CO2的零排放。目前最有效的生物质能利用方式就是将生物质按照一定的比例在电站燃煤锅炉中与煤混燃。另外,电站燃煤锅炉排放的烟气中含有大量的氮氧化物(NOx),对环境危害极大。把生物质作为电站燃煤锅炉再燃燃料来还原氮氧化物(NOx),既可高效利用生物质能,又可以降低污染物(CO2、NOx等)的排放,具有显著的社会效益。     

生物质能利用技术的开发研究

１国外生物质资源的利用现状与前景随着生物质能源转化技术的发展，以及人们对于改善环境要求的提高，生物质能所起的作用越来越重要。据估计，目前世界总能源消费中，１４％的能源供应来自生物质能，在发展中国家生物质能约占农村用能的９０％；在发达国家，如欧共体国家能源消费中２％到２５％是由生物质能提供的，一些世界能源组织（ＩＥＡ）成员国，生物质能在总能耗中所占份额高达１５％。在某些地区，生物质能已发挥了重要作用，例如美国加利福尼亚州的生物质能发电功率已大于１２００ＭＷ。在今后的数年内，利用生物质发电将成为一…     

世界各国重视开发和利用生物质能

生物质能又称为“绿色能源”，它是指通过植物的光合作用而将太阳辐射的能量以一种生物质形式固定下来的能源，包括树木、青草、农作物、藻类、兽类及各种有机废物等。生物质能的应用有不同的形式，如可将树木、干草、秸秆等直接用作燃料，也可以通过某种方式将有机物质转化为沼气、酒精和油类等，用作燃料。开发和利用“绿色能源”已成为世界许多国家开源节流、化害为利和保护环境的重要措施。据联合国环境保护机构发表的一份调查报告说，至少有10多个工业化国家在开发利用“绿色能源”方面取得了显著成绩，其中有些国家通过实施“绿色能源…     

生物质直接燃烧技术的发展研究

随着能源危机和环境问题的日益严重,人们不断致力于开发研究低污染、可再生的新能源。在众多的可再生能源中,生物质能是一种储量丰富、清洁方便的绿色可再生能源,具有极大的开发潜力。为了大力开发利用生物质资源,分析比较了国内外生物质直接燃烧技术发展现状,提出应根据生物质燃料的燃烧特性,开发相应的燃烧技术和燃烧设备,以实现生物质资源的大规模集中高效利用。     

Oil palm biomass as a sustainable energy source: A Malaysian case study

It has been widely accepted worldwide that global warming is by far the greatest threat and challenge in the new millennium. In order to stop global warming and to promote sustainable development, renewable energy is a perfect solution to achieve both targets. Presently million hectares of land in Malaysia is occupied with oil palm plantation generating huge quantities of biomass. In this context, biomass from oil palm industries appears to be a very promising alternative as a source of raw materials including renewable energy in Malaysia. Thus, this paper aims to present current scenario of biomass in Malaysia covering issues on availability and sustainability of feedstock as well as current and possible utilization of oil palm biomass. This paper will also discuss feasibility of some biomass conversion technologies and some ongoing projects in Malaysia related to utilization of oil palm biomass as a source of renewable energy. Based on the findings presented, it is definitely clear that Malaysia has position herself in the right path to utilize biomass as a source of renewable energy and this can act as an example to other countries in the world that has huge biomass feedstock.     

生物质和煤混合燃烧实验

生物质与煤混合燃烧是一种综合利用生物质能和煤炭资源并同时降低污染排放的新型燃烧方式。本文在STA409C型热综合分析仪上对一种煤样和两种生物质样以及它们不同的比例所得的混俣试样进行燃烧特性分析。结果表明，在煤中加入生物质后，着火燃烧提前，同时可以获得更好的燃尽特性。生物质和煤混合后，发热量增加，提高了生物质的利用价值。     

生物质气化发电过程建模与优化

目前国内外在生物质气化发电技术方面,由于缺乏对生物质气化过程特性的建模和参数优化问题的研究,使得生物质燃气中焦油量和污染物的含量过高,燃气品质难以保证,进而对燃气轮机发电机组产生不利的影响,降低了气化燃气的利用价值。因此,对于生物质发电气化过程的建模和重要参数优化控制的研究和探讨具有重要的意义。     

A knowledge-based approach to the design of integrated renewableenergy systems

Integrated renewable systems utilize two or more renewable energy resources and end-use technologies to supply a variety of energy needs, often in a stand-alone mode. A knowledge-based design approach that minimizes the total capital cost at a preselected reliability level is presented. The reliability level is quantified by the loss of power supply probability. The procedure includes some resource-need matching based on economics, the quality of energy needed, and the characteristics of the resource. A detailed example is presented and discussed to illustrate the usefulness of the design approach     

Status and future prospects of renewable energy in Iraq

Iraq suffers from electricity shortages, and many challenges will have to be overcome to meet future increases in electrical demands. This investigation found that solar, wind and biomass energy are not being utilized sufficiently at present, but these energies could play an important role in the future of Iraq’s renewable energy. Additionally, the potential of offshore-wind energy in the Gulf (near Basrah in the southern part of Iraq) needs to be investigated. The Iraqi government's attempts to utilize renewable energy have been discussed. This paper aims to review and discuss the status and future of renewable energy in Iraq. The uses of renewable energy sources, such as solar, wind and biomass, have been reviewed. This paper concludes with recommendations for the utilization of these energy resources.     

烘焙对生物质热化学转化特性影响的研究进展

生物质是可再生能源的重要组成部分,储量巨大,但其含水量高、能量密度和热值低等缺点致使其研磨难度大、存储运输不便,难以资源化利用。本文对烘焙预处理技术的过程及特点、能耗分析和较为理想的烘焙标准进行了简述;并重点阐述了烘焙对生物质燃烧、热解和气化特性影响的研究进展。经烘焙处理后的生物质在炉膛内可快速、稳定燃烧,炉内温度迅速升高,产生的烟气量减少;热解产生的生物质焦油中水和乙酸含量明显减少,苯酚含量增加,热值总体升高;气化合成气品质明显提升,能量密度增大,总气化效率显著提高。此外,对烘焙预处理技术在城市固体废弃物处理的应用进行了简要的概述,并对其在生物质和城市固体废弃物研究方向上进行了展望。     

Performance investigation of a combined biomass gasifier-SOFC plant for compressed hydrogen production

As an alternative, clean and sustainable solution, a biomass-based integrated power plant is designed and studied both thermodynamically and parametrically. Due to the environmental, economic and performance related advantages, the design of multigeneration energy plants is now increasing and becoming widespread technology. Biomass, which is one of the renewable power sources, is selected for the plant to be more sustainable and environmentally friendly. The proposed system using biomass as an energy source consists of several sub-plants integrated to utilize the waste thermal energy and to generate useful products which are electricity, hydrogen, fresh and hot water, heating, and cooling. In this paper, comprehensive work is carried out for plant modeling and simulation. The thermodynamic assessment results reveal that both energetic and exergetic effectiveness of the whole plant are 56.17% and 52.83%, which are affected positively by varying the reference state conditions, combustor temperature, biomass gasifier temperature, SOFC temperature and pressure, and biomass mass flow rate. In addition, the lowest energy and exergy efficiencies occur in the ORC combined ejector refrigeration cycle with 21.87% and 18.26%, respectively.     

Simulation study of parameters influencing microwave heating of biomass

Experimental investigation of microwave-assisted pyrolysis was successfully done using a specially modified domestic microwave oven. At conditions where no parameterised experimental study was conducted (except temperature measurement), changing other parameters that influence the microwave heating can be investigated qualitatively in detail by means of simulation work. Therefore, a computer based simulation using Comsol Multiphysics software was applied not only to predict how the electromagnetic field distributes within the cavity but also to study different parameters that influence heating distribution inside the microwave oven. The simulation work was initially performed with verification between experimental and simulation temperature profiles at temperature settings of 500 °C and 800 °C and an agreement was achieved in terms of the temperature profile and heating behaviour of the biomass. The simulation work has proved that the inhomogeneity of temperature of the biomass is reflected by the local occurrence of hot spots and cold spots. The effect of different positions of the waveguide is remarkable where the bottom-fed microwave energy oven was shown to have a poor electric field distribution. However, when simulation was done on combining the effect of having the microwave energy fed from the bottom and the presence of the mode stirrer, the electric field was greatly improved with the heating distribution of the biomass resembling that obtained from the side-fed microwaves energy oven (usually refers to a common home microwave oven). The effect of having a mode stirrer rotating inside the microwave oven is also pronounced where the mode stirrer acts to stir the electric field strength within the cavity so that a more uniform heating within the biomass can be achieved. Interestingly from the simulation, for a specified microwave cavity, an optimum bed size of biomass was found at 50 mm height where maximum microwaves energy absorption takes place. In this sense, more microwaves energy can be converted into heat thereby ultimately helping the biomass to reach the desired pyrolysis temperature in shorter time. The COMSOL modelling on microwave heating therefore has shown to be simple and practical for use as a framework in predicting temperature profile of the biomass and intensity of the electric field.