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1.
Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising
system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following
basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition
of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded
completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental
data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme.
Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China 相似文献
2.
Kinetics study on biomass pyrolysis for fuel gas production 总被引：1，自引：0，他引：1
INTRODUCTIONSincebiomassisanabundant,inexpensiveandrenewableresource ,itsconversiontosyn theticfuelsandchemicalproductsappearsat tractive.Amongallkindsofbiomassconversionroutes,pyrolysisisbeinggivenincreasingatten tionsincetheprocessissimpleandmaybeopti m… 相似文献
3.
Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion. 相似文献
4.
基于CMAQ模拟结果,统计、归纳出各种污染物排放控制因子与污染物浓度之间的函数关系,建立空气质量响应曲面模型RSM,通过留一法交叉验证和外部验证对模型进行可靠性验证。使用RSM,研究不同污染物的PM2.5响应值,评估现有政策不变（Ⅰ）和政策收紧（Ⅱ）两种减排情景,发现NOX、SO2、NH3和VOC对PM2.5浓度体现明显的非线性响应特征,情景Ⅱ的减排效果明显好于情景Ⅰ,夏季的减排效果好于冬季。 相似文献
5.
INTRODUCTION Turbulent gas-particle flows are frequently found in natural phenomena and industrial processes.Cases of cylinders in cross flows with particles occur in heat exchange equipment,including the convective zone of a fluidized-bed combustor,and in the primary superheaters,reheaters,and economizers of coal-fired boilers.Coherent structures often occur in the above-mentioned gas-particle flow,and have great effect on such different systems,while some features of tur-bulent multiphas… 相似文献
6.
ＩＮＴＲＯＤＵＣＴＩＯＮＭａｎｙｅｘｐｅｒｉｍｅｎｔａｌａｎｄｎｕｍｅｒｉｃａｌｓｔｕｄｉｅｓｈａｖｅｂｅｅｎｃｏｍｐｌｅｔｅｄｔｏｉｎｖｅｓｔｉｇａｔｅｔｈｅｐａｒｔｉｃｌｅｍｏｔｉｏｎｉｎｔｕｒｂｕｌｅｎｃｅ .Ｐｒｅｖｉｏｕｓｆｌｕｉｄｄｙｎａｍｉｃｓｓｔｕｄｉｅｓｗｅｒｅｃｏｍｍｏｎｌｙｂａｓｅｄｏｎｔｉｍｅ ａｖｅｒａｇｅｄＲｅｙｎｏｌｄｓｅｑｕａｔｉｏｎｓ,ｓｕｃｈａｓｔｈｅｔｗｏ ｅｑｕａｔｉｏｎｍｏｄｅｌ.Ｊｕｓｔｌｉｋｅｔｈｅｃａｒｒｉｅｒｇａｓｐｈａｓｅ,ｔｈｅｐａｒｔｉ ｃｌｅｐｈ… 相似文献
7.
An improved mathematical model for a circulating fluidized bed (CFB) boiler based on the model developed earlier by the authors was applied to simulate the operation of a 12 MW CFB boiler. The influences of the excess air ratio, primary air ratio, coal particle size distribution, coal properties (ash content and volatile content) and Ca/S ratio on the boiler operation were analyzed. The results showed that the model simulation may be applied to the optimum design and economic operation of the CFB boiler. 相似文献
8.
The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000℃ at a heating rate of 10 oC/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results. 相似文献
9.
岑可法 《高等工程教育研究》2005,(1):16-18
近些年来 ,我国高等教育发展迅猛 ,取得了举世瞩目的成就 ,但也遇到了一些新问题 ,其中 ,研究型大学工科专业的培养目标如何定位 ,就是一个争议颇多而又事关重大、亟待解决的问题。许多有识之士对一些有传统工科背景的重点高校放弃“工程师的摇篮”这一美誉深表遗憾和忧虑 ,认为培养目标定位不准 ,将对我国工程技术队伍的整体素质、对我国产业结构的优化完善、进而对我国综合国力的可持续增长产生不利影响。为此 ,本刊特辟专栏 ,邀请我国高教界、工程界、科技界的部分知名专家 ,就此展开笔谈。从此次发表的几篇文章看 ,专家们对于研究型大学的工科专业应当培养高级工程人才虽然意见大体一致 ,但对于培养什么样的工程人才、现代工程师是否应当成为主要的培养目标 ,乃至何谓现代工程师 ,专家们从各自的经验和视角出发 ,却是仁者见仁 ,智者见智。这也足以说明 ,就研究型大学工科专业的培养目标定位展开讨论 ,也许并不是一个明知故问的多余之举。我们期待更多的有识之士就此发表高见。 相似文献
10.
To find out the detailed characteristics of the coherent structures and associated particle dispersion in free shear flow, large eddy simulation method was adopted to investigate a two-dimensional particle-laden wake flow. The well-known Sub-grid Scale mode introduced by Smagorinsky was employed to simulate the gas flow field and Lagrangian approach was used to trace the particles. The results showed that the typical large-scale vortex structures exhibit a stable counter rotating arrangement of opposite sign, and alternately form from the near wall region, shed and move towards the downstream positions of the wake with the development of the flow. For particle dispersion, the Stokes number of particles is a key parameter. At the Stokes numbers of 1.4 and 3.8 the particles concentrate highly in the outer boundary regions. While the particles congregate densely in the vortex core regions at the Stokes number of 0.15, and the particles at Stokes number of 15 assemble in the vortex braid regions and the rib regions between the adjoining vortex structures. 相似文献