【作者】 衡明星；

【导师】 孙培勤； 陈俊武；

【作者基本信息】 郑州大学 ， 工业催化， 2010， 博士

【摘要】 随着有限的化石燃料日益枯竭及全球能源消耗的急剧增长,研究和利用可再生能源的意义十分重大。生物质资源作为一种可直接液化的可再生能源引起世人格外关注。以水为反应介质,进行泡桐催化液化基础研究具有重要的学术理论意义和工程应用价值。泡桐在水中直接液化时的产油率和液化率受多因素影响。本文以泡桐为原料以水为溶剂,在1L间歇式高压反应釜中进行直接液化实验,通过预试验设计对反应温度、停留时间和液料比进行了考察。预试验条件下,以得到最大重油率为目的时的泡桐直接液化的最优且最经济工艺条件为反应温度300-C、停留时间10mmin、液料比为6。这为泡桐在水中直接催化液化的实验条件的确定提供了参考依据。然后通过单因素实验法考察了反应温度、停留时间与铁粉或碳酸钠催化剂加入量对泡桐以水为溶剂直接液化的影响规律。实验发现生物质泡桐在水中直接液化时添加催化剂后可明显提高重油率和轻油率,降低固体残渣率。以均相的碳酸钠溶液为催化剂时泡桐在水中直接液化重油最大收率为31.92%,以非均相的还原铁粉为催化剂时泡桐在水中直接液化重油最大收率为36.34%,均显著大于不加催化剂时的重油最大收率27.01%；而以均相的碳酸钠溶液为催化剂时泡桐在水中直接液化最少的固体残渣率为7.23%,以非均相的还原铁粉为催化剂时泡桐在水中直接液化最少的固体残渣率为8.12%,均显著低于不加催化剂时的最少的固体残渣率为18.67%。使用气相色谱对泡桐直接液化后的气相产物组分进行定性和定量分析,发现生物质液化后的气体产物组成主要为体积分数大约为90%的C02,还含有大约体积分数9%的CO和体积分数1%的CH4。泡桐直接液化后的生物油中化合物种类繁多、成分复杂。通过使用傅里叶变换红外光谱仪对泡桐直接液化后的固体残渣和液相生物油产物的分析,研究了反应条件对生物质泡桐直接液化产物的基团结构影响,利用气质联用分析仪对泡桐液化后的生物油可挥发组分进行了定性和定量分析。研究发现泡桐液化后的轻油中主要组成为酚类、酮类、脂肪酸及芳香酸、呋喃衍生物、酯和醛；重油中主要组成为酚类衍生物、分子量较大的酮类、脂肪酸、芳香酸、酯、苯衍生物和醛。生物油的定性和定量分析结果为其在化工和能源方面的综合利用提供了基础资料。生物质液化工艺开发和设计都需要生物质转化过程中的热力学和动力学性质。本文对泡桐在水中直接液化过程的热力学和水解反应机理进行了计算和模拟,将泡桐液化后的轻油视为初始物A,将重油视为中间产物Q,将气体、水和固体残渣视为最终产物P,泡桐在水中直接液化过程可看作为一个单组分的连串反应。通过计算泡桐直接液化过程中第一步与第二步反应的反应速率,可知泡桐液化的机理为第一步生成重油Q是快反应,而第二步生成气体、水和固体残渣为慢反应,决定反应总速度的是第二步生成气体、水和固体残渣的反应。更多还原

【Abstract】 With the increasing depletion of limited fossil fuels and the rapid growth of global energy consumption, it is of great significance to research and make use of biomass energy. Biomass energy attracts the worldwide attention as it is a renewable energy which can be liquefied directly. So, it is of great value on academic theory and engineering application to do the basic research on paulownia catalytic liquefaction with water as the reaction medium.The oil product rate and the rate of paulownia direct liquefaction in water are affected by many factors. Paulownia direct liquefaction is processed in a 1L batch autoclave with water as a solvent. And the reaction temperature, residence time and liquid ratio are investigated by the pre-experiment design. At the pre-experiment conditons, the best and most economical condition for the purpose to get the maximum heavy oil yield is that the reaction temperature is 300℃, residence time is 10 min and liquid ratio is 6.This provides a reference for the determination of experimental conditions of paulownia direct liquefaction in water. Then the affection law of reaction temperature, residence time and the amount of iron powder or soda catalyst is investigated through the single factor optimization. It is found that the heavy oil rate and light oil rate are significantly improved while the solid residuse rate reduced when catalyst is added. The maximum heavy oil rates of paulownia direct liquefaction are 31.92% and 36.34% with homogeneous sodium carbonate solution and non-homogeneous reduced iron powder catalysts, respectively. Both are significantly higher than 27.01% obtained without catalyst. While the minimum residue rate is 7.23% with homogeneous sodium carbonate solution catalyst and 8.12% with non-homogeneous reduced iron powder catalyst. Both are significantly lower than 18.67% obtained without catalyst. The gas products of paulownia direct liquefaction are analyzed qualitatively and quantitatively by gas chromatography, and it is found that the gas products are mainly composed of about 90% of the volume fraction of CO2, and also contain about 9% of CO and 1% of CH4. The bio-oil products are complex and have a wild range of compounds. The influence of the reaction conditions is researched on the group structures of the products when the solid residues and liquid bio-oil are analyzed by Fourier transform infrared spectroscopy. The volatile component of bio-oil are qualitative and quantitative analyzed using GC analyzer and it is found that the light oils are mainly composed of phenols, ketones, fatty acids and aromatic acids, furan derivatives, esters and aldehydes while the heavy oils mainly contain phenolic derivatives, high molecular weight ketones, fatty acids, aromatic acids, esters, benzene derivatives and aldehydes. The qualitative and quantitative analysis results of bio-oil provide the fundamental information for its comprehensive applications in the chemical and energy industry.Thermodynamic and kinetic properties in the process of biomass conversion are required for the development and design of biomass liquefaction technology. Thermodynamics and reaction mechanism of hydrolysis on the process of paulownia direct liquefaction in water are calculated and simulated. If we assume the light oil as the initial product A, the heavy oil as intermediate Q while the gas, water and residues as final product P, and then paulownia direct liquefaction process in water can be seen as a series of single component consecutive reactions. By calculating the first and the second step reaction rate of the process, we can know the mechanism of paulownia liquefaction is that the first step to produce heavy oil is fast reaction and the second step to produce gas, water and solid residues is slow reaction which determines the whole reaction rate.更多还原