【作者】 于连林；

【导师】 鲍卫仁；

【作者基本信息】 太原理工大学 ， 生物化工， 2009， 硕士

【摘要】 近年来,随着石油越来越紧缺,科研人员开始寻求燃油的替代品。考虑到生物质的可再生性,生物质热解油技术受到了广泛的关注。然而生物质热解油的热值低、粘度大、氧含量高且热不稳定,使得热解油直接替代石油燃料的潜能受到限制。国内外很多学者围绕生物质热解油的改性进行了大量的探索研究。目前,固体酸催化酯化法被认为是一种有效的热解油改性技术,但此方法是否对所有热解油都有明显的改性效果,值得更深入的研究。当前此领域研究的比较透彻的是固体酸催化酯化反应改性稻壳、木屑等生物质热解油,但对玉米芯这种在中国广大农村地区普遍存在的农作物废弃物所制取的热解油,用催化酯化法改性其性质还很少有科研人员对其进行深入系统的研究。基于以上认识,本试验针对玉米芯单一生物质中温500℃热解所产生的热解油为研究对象,加入无水乙醇后进行固体酸催化酯化反应,考察催化酯化反应对玉米芯热解油比重、黏度、热值、分子量及主要成分的影响,探究固体酸催化酯化法是否能有效的提升玉米芯热解油的品质。研究发现,利用自制固体酸SO2-4/TiO2-SiO2催化酯化玉米芯热解油后,玉米芯热解油小分子量物质含量稍有降低,较大分子量的物质有所增加,热解油的比重变化不明显,黏度明显升高,热值有所升高,但幅度不大,这与用固体酸催化酯化改性稻壳、木屑等热解油结果有所差异,此方法对这类热解油的比重几乎没有影响,且能有效降低热解油的黏度,明显提高热解油的热值。就热值而言,固体酸催化酯化反应确实能提高玉米芯热解油的热值,但提高幅度不大,且热值提高的同时,热解油的黏度不降反升,这对玉米芯热解油作为燃油替代品来说,是极其不利的。本试验对玉米芯热解油做了GC-MS分析,GC-MS图谱显示玉米芯中温热解所制取的热解油的成分是有机酸、酮、醛、酚等含氧有机物,其中糠醛、苯酚及其衍生物(主要为对乙基苯酚、2-甲氧基苯酚、2-甲氧基-4-乙基苯酚)含量高达54%。反应后成分有所变化,但主要成分糠醛、苯酚及其衍生物含量变化不明显,与其它热解油相比,玉米芯热解油不含乙酸,而木屑、稻壳等热解油乙酸含量高达11%,这就决定了主要通过酯化反应(除催化酯化反应外固体酸还是异构化,缩醛等反应的催化剂)提升热解油品质的催化酯化法对玉米芯热解油的改性意义不大,但玉米芯热解油中糠醛、苯酚、对乙基苯酚、2-甲氧基苯酚、2-甲氧基-4-乙基苯酚含量较高,这些物质是非常有用的化工原料,从玉米芯热解油中提取这些化工原料可能对玉米芯的利用意义更大。更多还原

【Abstract】 In recent years, researchers began to do search for fuel alternatives, due to the shortage of the non-renewable resource petroleum. Taking into account renewable property, biomass pyrolysed oil (bio-pyro-oil) technology has been widely paid attention. However, pyro-oil has been thermal instability, low heat value, high viscosity and oxygen content, making the pyro-oil as direct substitute for fuel oil limited. Many scholars did a lot of research in order to change the negative property of pyro-oil as fuel at home and abroad .Upgrading pyro-oil over solid acid by esterification is considered to be an effective technology. Current research in this area is relatively focused on refining rice husk, wood chips and other bio-pyro-oil, rarely without considering refining corncob pyro-oil that are widespread in china.Based on the above condition, this test only probe into solid acid catalysed esterification to corncob pyro-oil, and then inspecting its density, viscosity, calorific value, molecular weight and major component changes, in order to make sure if this method is effective for refining corncob pyro-oil.The experimental results show that Corncob pyro-oil content of small molecular weight material reduce slightly and the larger ones increase; The density of pyro-oil did not change obviously, but the viscosity reduced sigificantly and the calorific value marginally raised after esterification reaction. The results are different with those published literature. In recent years, research in this area has been focused on the pyro-oil from the rice husk, wood chips or a mixture of both. Researchers found that the solid acid catalyst esterification method for density of such pyro-oil had little impact, and can effectively reduce viscosity of the pyro-oil, while the calorific value has been obviously improved. The solid acid catalyzed esterification can indeed improve corncob pyro-oil calorific value too, but the viscosity did not fall but rise, which is extremely negative for corncob pyro-oil as fuel alternatives. The component of corncob pyro-oil be different with others may lead to the results. GC-MS analysis show corncob pyro-oil (500℃pyrolyzed) are organic acids, ketones, aldehydes, phenols and other oxygenated organic compounds mixture, and furfural, phenol and its derivatives (mainly for ethyl phenol, 2 - methoxy-phenol, 2 - methoxy -4 - ethyl-phenol) content up to 54%. The components of pyro-oil change slightly after reaction, but the major components furfural, phenol and its derivatives did not change basically. Compared to other pyrolysis oil , corncob pyrolysis oil does not contain acetic acid, but acetic acid content up to 11% in pyro-oil from wood chips, rice husk pyro-oil, which make the way mainly through esterification reaction to enhance the quality of pyro-oil very little meaning for corncob pyro-oil. However, corncob pyro-oil contains useful chemicals such as furfural, phenol, and ethyl phenol, 2 - methoxy-phenol, 2 - methoxy -4 - ethyl phenol with a high level, which means extracting chemical industrial materials from corncob pyro-oil have greater significance.更多还原