生物质低温热解特性研究

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	生物质低温热解特性研究
其他题名	Low Temperature Pyrolysis Characteristics of BiomassLow Temperature Pyrolysis Characteristics of Biomass
	吴逸民
导师	赵增立
	2009-05-31
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
学位专业	环境工程
关键词	生物质低温热解热重分析裂解气质联用螺旋反应器
摘要	在能源和环境的双重压力下，生物质能的开发利用受到人们的广泛关注，其中生物质通过热解技术可以转化成气态、液态和固态燃料以及其它化工产品。生物质主要由纤维素、半纤维素和木质素组成，它们的热解特性有较大差异。利用生物质主要组分热解特性的不同，选择合适的反应温度进行选择性热解可获得相应的目标产物，热解固体产物可以用于燃油制备，为高效利用生物质提供了一条新的技术路线。本文在国家高技术研究发展计划项目的资助下，开展了生物质低温热解的特性研究，考察生物质及其主要组分在低温下的热解特性。首先采用热重分析仪和裂解气质联用分析仪对生物质的主要组分在低温下进行热解特性研究，研究结果表明生物质主要组分的热稳定性为：纤维素>木质素>半纤维素，半纤维素热解产物主要有乙酸、1-羟基-丙酮和1-羟基-2-丁酮，纤维素热解产物主要有左旋葡聚糖和脱水纤维二糖，而木质素热解产物主要是邻甲氧基苯酚。桉木、玉米芯和杉木的直接热解裂解气质联用实验考察了温度和化学组分对低温热解产物的影响，桉木和玉米芯低温热解的呋喃类化合产物、杉木的萜类化合物以及它们的酸类化合物相对含量随温度上升而降低，而桉木和杉木低温热解的酚类化合产物相对含量则随温度上升而增加。逐级热解裂解气质联用实验考察了生物质原料在低温不同温度区间热解产物的分布规律，桉木、玉米芯和杉木在25-350℃低温区热解产物种类较少，桉木热解产物主要是5,6-二氢-4-羟基-吡喃-2-酮，玉米芯主要为2,3-二氢-苯并呋喃和4-羟基-2-甲基苯乙酮，杉木主要是雪松醇和4-羟基-2-甲氧基肉桂醛。桉木在450-500℃热解产物较多，以酮类和芳香类化合物为主；玉米芯在400-450℃热解产物较多，以酮类化合物为主；杉木在400-500℃热解产物较多，以酮类和芳香类化合物为主。在螺旋热解反应器中进行了杉木和稻草的低温热解试验，试验结果表明生物质原料在240-320℃发生热解失重主要由于其半纤维素组分的热解，该温度段的热解液体产物水分含量较高，甲醇、乙酸和1-羟基-丙酮都是主要的热解液体产物，气体热解产物则主要以CO和CO2为主，另外还有少量H2和CH4。生物质的热解产物来源于其不同的化学组分，而各化学组分的热解温度区间有较大差异，在不同温度区间最大限度分解相应的主要化学组分，获得目标产物，可以实现生物质资源高值化的综合利用。
其他摘要	To solve the problem caused by energy shortage and environmental pollution, the exploitation and utilization of biomass energy has been paid more attention during these years. Biomass can be converted into gaseous, liquid and solid fuels and other chemical products by pyrolysis technology. Biomass is mainly composed of cellulose, hemicellulose and lignin, which have apparently different pyrolysis characteristics. In view of the different of pyrolysis characteristics of the major components of biomass, it is possible to obtain desired target products from selecting pyrolysis of the major components of biomass. Production of the high quality bio-oil from degradation of residual solids provides a good technical route to utilize of biomass high efficiently. The present work focused on investigating the low temperature pyrolysis characteristics of biomass and major components of biomass. The project was funded by National High-Tech Research and Development Program of China (2007AA05Z456). Firstly the low temperature pyrolysis characteristics of major components of biomass were investigated by TGA and Py-GC/MS. The experimental results showed that thermal stability of major components of biomass was in descending order of cellulose>lignin>hemicellulose, and the major components of biomass had different contribution to the volatiles from the pyrolysis process. The degradation of hemicellulose generated acetic acid, 1-hydroxy-propanone and 1-hydroxy-2-butanone. The high yield of levoglucosan and anhydro-cellobise was from the pyrolysis of cellulose. Guaiacol was associated with the degradation of the lignin. Direct pyrolysis experiment was carried on eucalyptus, corn cob and fir by Py-GC/MS to investigate the influence of temperature and chemical components on the product of biomass low temperature pyrolysis. Increasing the heating termperature decreased the relative contents of furan products from pyrolysis of corn cob and eucalyptus, terpene products from pyrolysis of fir, acid products from pyrolysis of all, and increased that of phenol products from pyrolysis of eucalyptus and fir increases. However, the pyrolysis products distribution among different temperature range were investigated by step-pyrolysis experiments of Py-GC/MS. There were relatively less components in the pyrolysis products when eucalyptus, corn cob and fir were pyrolized under low temperature condition as 25-350℃, the main products of eucalyptus were 5,6-dihydro-4-hydroxy-2h-pyran-2-one, whereas 2,3-dihydro-benzofuran and 4-hydroxy-3- methylacetophenone of corn cob, cedrol and 4-hydroxy-2-methoxycinnamaldehyde of fir. There were more yield and species of eucalyptus pyrolysis products generated in the temperature range of 450-500℃, in which step the pyrolysis products were found in form of ketones and aromatics. Similar to eucalyptus, the yield and species are much when corn cob and fir pyrolyzed under the temperature of 400-450℃ and 400-500℃ respectively. The dominate pyrolysis product of corn cob were ketones when the temperature range is 400-450℃, and that of fir were ketones and aromatics when temperature range is 400-500℃. The low temperature pyrolysis experiments of fir and straw were carried out in a screw reactor. The experimental results showed the weight loss of biomass occurred at 240-320℃ due to the hemicellulose of biomass pyrolysis. Pyrolysis liquid products of low temperature pyrolysis had a high content of water, and the main products were methanol, acetic acid and 1-hydroxy -propanone. The main gas products were CO and CO2, and a few of H2 and CH4. Different pyrolysis products were produced from different chemical compositions of biomass, due to their different pyrolysis temperature ranges. It is possible to obtain various desired target products at different temperature ranges from pyrolysis of the main corresponding chemical compositions of biomass. This is believed a good approach to achieve utilization of biomass resources.
页数	69
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/4033
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	吴逸民. 生物质低温热解特性研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2009.

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