【作者】 廖益强；

【导师】 陆则坚； 黄彪；

【作者基本信息】 福建农林大学 ， 农产品加工及贮藏工程， 2010， 博士

【摘要】 生物质快速热解（biomass fast pyrolysis）液化技术是可再生能源发展领域中的前沿技术之一。在国内外众多的生物质快速热解液化装置类型中,流化床反应器（fluidized reactor）制造工艺比较成熟,应用最为广泛。笋壳（Bamboo Shoot Shell）是农产品竹笋加工过程的剩余物,作为一种优质的生物质,笋壳的纤维素、木质素的含量很高。利用笋壳为原料通过流化床快速热解方式制取生物质油,具有重要的环境效益、经济效益和社会效益。本文在国家林业局“948”项目“木屑和锯末热解制取洁净燃料和化学品技术”的依托下,根据鼓泡流化床的特点以及笋壳的热解特性,研制出生物质快速热解的流化床热解反应器,并以笋壳为原料进行快速热解制取生物质油的实验研究,采用FTIR、GC-MS对生物质油进行分析。具体研究工作如下:1、自行研制出生物质流化床快速热解装置。本装置给出以变径、变螺距加气流输送的螺旋给料机的设计思想、设计方法和计算过程;从反应器的处理能力入手,进行物料衡算和热量衡算,设计计算流化床反应器的结构和几何尺寸以及各附属设备的选型;研究分析生物质热解产物特性、旋风分离器的工作原理以及结构,给出合理设计及相关计算,实现气固产物高效分离;提出生物质油骤冷冷凝器的设计思想,为达到骤冷目的,采取二次冷凝的构想和设计思路。2、通过对毛竹笋壳进行热重分析（TG）、红外光谱分析（FTIR）、热解过程的动力学分析,求取笋壳热解过程的反应的活化能及动力学参数。试验结果表明:笋壳的红外吸收光谱图主要由烃基、碳基、碳水化合物及苯环等吸收带组成。笋壳的热解（TG曲线）过程分为脱水、预热解、热解（剧烈失重）、炭化（缓慢失重）四个阶段,主反应阶段主要集中在250～650℃左右。生物质热解的快慢主要取决于原料粒径和升温速率两个影响因素。用Doyle法求出不同升温速率下笋壳热解的表观活化能在120～160 kJ·mol^-1之间,利用动力学补偿效应得出了相应的动力学参数,确定了笋壳热解反应的动力学方程,认为一级反应模型可以对反应机理进行较好的描述。3、以毛竹笋壳为原料,石英砂为流化介质,在自行研制的流化床快速热解装置上进行热解试验。研究热解温度、物料尺寸、进料速率、滞留时间、不同添加剂对生物质油产率的影响。试验结果表明:四种添加剂中添加剂Ⅳ的效果最好,加入添加剂Ⅳ笋壳快速热解温度可以降低将近100℃;笋壳的物料尺寸为小于1 mm比较适合本实验装置;进料速度是50 g·min^-1、滞留时间是小于1 s、添加剂Ⅳ浓度0.4 %,生物质油的产率可达66.7%。4、利用FTIR和GC-MS分析了毛竹笋壳生物质油的主要化学成分,并测定其元素组成和理化特性。试验结果表明:生物质油的性能与锅炉燃油有一定的差别,主要是热值比锅炉燃油低,含氧量高达38.5%,作为燃油使用,还需要进行改性;根据FTIR分析和GC-MS的分析结果可知,笋壳生物质油成分很复杂,其中添加剂Ⅳ的笋壳热解油含有的可辨识化合物有38种。生物质油中主要含有机酸类、芳香烃类、烷烃类、酚类、苯酚类、苯环类等化合物,其中酚类衍生物相对含量可达55%左右,可以用来部分代替苯酚制取酚醛树酯胶粘剂。更多还原

【Abstract】 The technology of biomass fast pyrolysis is one of the most important technologies in the fields of renewable Energy. The fluidized bed recator which is one of the advanced biomass pyrolysis reactor is widely used in the world. As a high-quality biomass, bamboo shoot shell high contains cellulose and lignin. Bio-oil from fast pyrolysis of bamboo shoot shell in the fluidized bed takes on important environmental, economic and social benefits. This paper relys on projects“the technologies of saw wood powder pyrolysis for nonpollution fuel and chemicals”which is the national“948”technology projects in the area of energy. In this paper, based on characteristics of fluidized bed and bamboo shoot shell, the reactor of biomass fast pyrolysis were designed and manufactured. Bio-oils from fast pyrolysis of bamboo shoot shell were researched in the reactor. By using FTIR and GC-MS, the bio-oils were anaylzed. The detailed studies are as follows:1. The experimental equipment of biomass fast pyrolysis in the fluidized bed was designed and manufactured. Design method and calculation procession of screwy feed-in implement which holds different diameters and volution distance were used in the equipment. From the treatments of bamboo shoot shell, mass balance and heat balance were carried out and the structures of fluidzied bed reactor were calculated. Cyclone separator was designed rightly by analyzing bio-oil properties and working principles of cyclone separator. In order to quenche, the design ideas of condensation implement which contains two steps cooling were put forward.2. By analysis TG, FTIR and kinetic analysis of pyrolyisi process from the mao bamboo shoot shell, reactive activation energy and kinetic parameters of the thermal decomposition process were achieved. The experimental results showed that the spectra of bamboo shoot shell infrared absorption was mainly made up of absorption bands of alkyl, carbon-group, carbohydrate and benzene-loop and so on. Bamboo shoot shell pyrolysis process (TG curve)was divided into four phases, such as dehydration, pre-pyrolysis, pyrolysis (severe lossing of weight), carbonization (slow lossing of weight). Reaction stage mainly concentrated in about 250～650℃. The speed of bamboo shell pyrolysis depended on the effect factors of raw materials size and heating rate. By using Doyle method, activation energy of bamboo shoot shell in different heating rates which were 120～160 kJ·mol-1 was calculated. By using the kinetic compensative, the corresponding kinetic parameters were obtained and the pyrolysis kinetic equation of bamboo shell was determined. It was considered that the reaction mechanism could be better described by one grade reaction model.3. Pyrolysis experiment with the shoot shell was carried out in the self-designed fluidized bed in which quartz sand was used as the fluidizing medium. The effects of bio-oil yields on pyrolysis temperature, material size, feeding rate, retention time and different additives were studied. The best pyrolysis process conditions of fast pyrolysis were explored. The results showed that additiveⅣwas one of the best additives, pyrolysis temperature would descend about 100℃with the additiveⅣ. Material size below 1mm was adapt to the equipment. As the feeding speed 50 g·min-1, retention time below 1 s, the concentration of additiveⅣ0.4%, bio-oil maximum yields could be 66.7%.4. By using FTIR and GC-MS, the major compositions of bio-oils were analyzed, then elements composition, chemical and physical properties of the bio-oil were measured. The experimental results showed that the performance of bio-oils was a little different from boiler fuels, mainly lying in the calorific value and oxygen content. If bio-oil will be used as fuels, it need to be refined. According to the results of FTIR and GC-MS analysis, the bio-oil composition was very complex. There were 38 kinds of recognizable compounds in the bio-oils from the bamboo shell which were added additiveⅣwhile pyrolysising. The bio-oils mainly contained organic acids, hydrocarbons, hydroxybenzene, phenols, benzene compounds and so on. Due to relatively high content of hydroxybenzene ramification which was up to 55%, the bio-oils could be used to produce the adhesive system.更多还原