【作者】 杨海平；

【导师】 郑楚光； 陈汉平； 晏蓉；

【作者基本信息】 华中科技大学 ， 热能工程， 2005， 博士

【摘要】 油棕是马来西亚和印度尼西亚的主要经济作物,其废弃物的高效、洁净转化技术的开发和研究不仅有益于东南亚各国经济的可持续发展,而且对地区的环境保护和能源利用也有着重要意义。本文依托华中科技大学煤燃烧实验室和新加坡南洋理工大学环境科学工程研究院国际合作项目“油棕废弃物的能源化利用”对油棕废弃物的热解技术展开了全面的研究,所做的工作主要有以下几个方面: 利用热重分析仪(TG)对油棕废弃物和生物质主要组分(半纤维素,纤维素和木质素)的热解特性进行了系统的研究,对比分析了它们在热失重曲线中体现出的不同规律并计算了各自的动力学参数,同时还研究了升温速率和生物质样品的颗粒尺寸对生物质热解特性的影响。鉴于TG 和傅立叶红外光谱仪(FTIR)联用技术的快速性和在线分析的特点,利用TG-FTIR 对油棕废弃物的热裂解的气体产物的析出特性进行了检测分析,主要研究了热解温度对气体产物的影响,并从化学结构入手,分析了生物质的热解行为以及气体产物的形成机理,结果表明生物质样品热解的主要气体产物为CO2、CO、CH4、H2O 和有机碳氢化合物,温度对油棕废弃物热解,尤其对热解产物的成分有显著作用,这为生物质热解机理的研究提供了依据。基于简单格子法,在热重分析仪上对三组分(半纤维素,纤维素和木质素)间的相互作用进行了详细的研究,发现三种组分间不存在明显的相互作用,它们在热解过程中独立的发挥着重要作用,并建立了与生物质热解特性和三组分含量相关的数学模型,以预报生物质样品的热解特性或用于计算样品中三组分含量,计算结果与实验结果有很好的一致性。然而对于天然生物质,所含灰分对其热解有显著的影响,为了详细了解矿物质灰分对生物质热解特性的影响,接着引入了六种主要金属(K、Mg、Ca、Na、Fe 和Al)的矿物质盐或氧化物,在热重分析仪上研究了矿物质对三组分的热解失重特性的影响,并利用TG-FTIR 联用技术在线分析了灰分对油棕废弃物热解失重和气体产物释放特性的影响,为全面理解矿物质灰分的存在对生物质热解特性的影响打下了基础。为进一步了解生物质热裂解机理和裂解产物(气体产物、液体生物油和固体焦炭)的形成特性,采用堆积床和气相色谱仪、FTIR、扫描电镜、还有色谱质谱联用等分析技术对油棕废弃物热解产物特性进行了详细研究,发现在堆积床上生物质的热解主要发生在400-700°C,对生物质的裂解机理有了一定的了解和认识。更多还原

【Abstract】 Palm oil wastes are the main biomass resources in ASEAN countries. The novel technologies, to treat this tremendous amount of wastes, with improved efficiencies and reduced environmental impacts need to be established timely. With the support of the coorperation between Huazhong University of Science and Technoligical State key Laboratory of Coal Combustion (China) and and Nanyang Technological University Insitute of Environmental Science and Engineering (Singapore) on the project of high efficient conversion of palm oil wastes to energy, we carried out a detailed research on palm oil wastes pyrolysis, the main investigation are listed as follows: The investigation of the pyrolysis of palm oil wastes and the main components of biomass (hemicellulose, cellulose and lignin) were preformed on thermogravimetry (TG), the difference of the three main components was analyzed, and their kinetics parameters was calculated using non-siothermal integrated method, simultaneously, the influence of heating rate and particle size on biomass pyrolysis was analyzed. The gas product evolved out from palm oil wastes pyrolysis was analyzed on-line using Fourier Transform Infrared Spectrometer (FTIR) coupled with TG,with focus on the effect of final temperature. The pyrolysis behavior of biomass and the forming characteristics of gas products were analyzed from the point of chemical functional groups. It was observed that the main gas products are CO2, CO, CH4, H2O and some organics, and temperature showed great influence on biomass pyrolysis, especially on gas product evolving. . The interaction among hemciellulose, cellulose and lignin was studied using TG based on Simplex-lattice, there is no significant influence among the three main components, following that, two sets of mathematics equations related to biomass pyrolysis and the contents of its main components were got through multiple linear regression. It can be used to simulate the pyrolysis characteristics according to the main components or biomass or based on its pyrolysis behavior to analysis the main components content. However, the inorganics matters in natural biomass samples caused some difference, to understand the influence of inorganics matters, six salts or oxides of the main metal (K、Mg、Ca、Na、Fe and Al)in biomass ash were introduced in to mixed with hemicellulsoe, cellulose and lignin to study their influence on biomass pyrolysis using TGA deeply, and to analysis the influence of inorganics matters on natural biomass sample, the pyrolysis of palm oil wastes pretreated through water wash and K2CO3 adding was analyzed using TG-FTIR, it showed that inorganics matters show great catalytic on biomass pyrolysis, it provide significant information to understand the influence of ash content on bomass pyrolysis. To get the further information of the forming characteristics of gas products, liquid oil and solid charcoal from biomass pyrolysis, the pyrolysis of palm oil wastes was carried out in packed bed with gas chromatograph, FTIR, SEM and GC-MS, etc. instruments. The optimal operating condition of pyrolysis product was suggested. It is important to understand the principle of biomass pyrolysis. H2, as the clean energy with high heat value, is the most interested product of biomass energy conversion. To upgrade the quality and yield of rich hydrogen gas products, the pyrolysis of palm oil wastes was carried out in countercurrent dropped bed with continuous feeding focused on the influence of final temperature, gas residence time and catalyst adding on gas product property. It was observed that higher temperature is favorable for H2 and CO flammable gas upgrading. Under the catalysis of Ni, the yield of hydrogen rich gas product reached 0.9m3/kg of biomass with 37vol.% H2. It is significant for the comprehensive understanding of biomass pyrolysis for producing H2, and supplies fundamental acknowledge for the technology of biomass conversion to hydrogen. The modeling of palm oil wastes pyrolysis was carried out using thermodynamics equilibrium simulation and kinetics, and the modeling results were compared with experimental one in the reactors involved, it showed great consistent and compatibility with each other. The further understanding of palm oil wastes pyrolysis was reached. The simulation is significant for the development of biomass thermochemcial conversion technology and the high efficient conversion of palm oil wastes to energy.更多还原