【作者】 柏静；

【导师】 孙孝敏；

【作者基本信息】 山东大学 ， 环境科学与工程， 2013， 硕士

【摘要】 生物质是指通过光合作用而形成的各种有机体,包括所有的动植物和微生物。而所谓生物质能,就是太阳能以化学能的形式贮存在生物质中的能量形式,即以生物质为载体的能量。目前很多国家都在积极研究和开发利用生物质能,通常包括木材、水生植物、森林废弃物、油料植物、城市和工业有机废弃物、动物粪便等。地球上的生物质能资源较为丰富,而且是一种无害的能源。但是,在关注生物质能带来便利的同时,也应当关注生物质本身排放的VOCs和生物质燃烧排放的有机物对环境的影响。本文以左旋葡聚糖和脱氢枞酸作为生物质燃烧释放的典型的分子示踪物和生物质排放的单萜烯(罗勒烯、月桂烯和芳樟醇)为代表物进行研究,采用高水平量子化学理论密度泛函方法(DFT),在MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p)水平上对左旋葡聚糖、脱氢枞酸、单萜烯在大气中的氧化降解机理做出了系统的研究与分析,并且使用RRKM-TST理论计算了相关的动力学数据。得到了一些有价值的研究成果：1.左旋葡聚糖的大气氧化降解机理及动力学性质OH自由基氢抽提反应是左旋葡聚糖大气降解的主要途径。本文采取高精度的量子化学方法研究了左旋葡聚糖与OH自由基可能进行的重要反应,并对形成的主要活性中间体在O2/NO/H2O存在条件下进行的大气反应作了研究。研究表明OH自由基抽提烷基上H的反应是主要的引发反应,其最终降解产物对大气酸度和SOA形成均有贡献。并且在298K时,左旋葡聚糖与OH自由基的反应速率常数为2.21×10-13cm3molecule-1s-1,计算得到其大气寿命为26天。2.脱氢枞酸的大气氧化降解机理及动力学性质研究了OH自由基和03分别引发的脱氢枞酸的大气氧化降解机理。对于OH自由基引发反应来说,OH自由基的加成反应和抽提反应都发挥着重要作用,并且RRKM计算结果表明：在298K时,OH自由基加成反应速率常数为2.00×10-12cm3molecule-1s-1,而H抽提反应速率常数为6.89×1012cm3molecule-1s-1,总包反应速率常数为8.9×10-12cm3molecule-1s-1。由于对流层中高的O3浓度,O3引发的加成反应同样也不能忽视,其反应速率常数为2.29×10-20cm3molecule-1s-1。3.单萜烯的氧化降解机理和动力学性质分别研究了罗勒烯、月桂烯、芳樟醇与03的反应机理,讨论了03分别加成到各个双键上的加成反应,以及在O2/NO/H2O存在条件下的二级反应。并且讨论了这三个单萜烯在液相中反应进行的趋势。在298K时,罗勒烯、月桂烯、芳樟醇与03反应的速率常数分别为7.19×10-16、3.51×10-19和3.83×10-16cm3molecule-1s-1。更多还原

【Abstract】 Biomass refers to the variety of organisms through photosynthesis, including all of the animals and plants and microorganisms. And so-called biomass energy, is the form of solar energy in the form of chemical energy stored in the biomass, that is take biomass as the carrier of energy. Now many countries are actively research and development and utilization of biomass energy, which usually includes wood, forest waste, aquatic plants, oil plants, urban and industrial organic waste, animal waste, etc. Biomass energy of the earth’s resources is relatively abundant and which is the energy of harmless. People pay attention to the advantages of biomass, but at the same time, they should also pay attention to the biomass itself emission of VOCs and biomass burning emission of organic matters impact on the environment.This paper based on levoglucosan and dehydroabietic acid as typical tracer molecules released by the biomass combustion and monoterpene (ocimene, myrcene, linalool) emission by biomass as the representative for research, using high level quantum chemical density functional theoretical method study and analysis their oxidation degradation mechanism in the atmosphere at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. And to calculated the related dynamic datas by using the Rice-Ramsperger-Kassel-Marcus(RRKM) theory. The detailed mechanism has lead to the following conclusions:1. The atmospheric oxidation degradation mechanism and kinetics properties of levoglucosanThis paper adopts the method of high-precision quantum chemical to study all the important reactions between levoglucosan and OH radical. The OH-initiated reaction of levoglucosan is one of the main eliminating ways. The possible subsequent reactions in the presence of O2, NO and H2O are also taken into consideration. The study shows that the H atom abstraction from the C4-position by the OH radical is an energetically favorable pathway, and the OH-initiated products contribute to the formation of SOA and atmospheric acidity. The rate constant of levoglucosan reacting with the OH radical at298K is2.21×10-13cm3molecule-1s-1and the atmospheric lifetime is26days ([·OH]=2.0×106molecule cm-3).2. The atmospheric oxidation degradation mechanism and kinetics properties of dehydroabietic acidIn this paper, the atmospheric mechanism of DHAA initiated by OH radicals and O3was studied at the MPWB1K/6-31+G(d,p)//MPWB1K/6-311+G(3df,2p) level. For OH-initaited reaction with DHAA, both OH-addition reactions and H-abstraction reactions are significant. The result of RRKM kinetic calculation shows thatthe rate constant of OH radicals with DHAA is8.9×10-12cm3molecule-1s-1at298K and under the pressure of760Torr. The rate constant of OH addition reaction is2.00×10-12cm3molecule-1s-1, while that of the H atom abstraction is6.89×10-12cm3molecule-1s-1. The O3addition to the aromatic ring of DHAA is vital to the atmospheric reactions, because the concentration of ozone is high in the troposphere and the ozone can participate in atmospheric reactions all day. And the rate constant of O3reacting with DHAA is2.29×10-20cm3molecule-1s-1.3. The atmospheric oxidation degradation mechanism and kinetics properties of monoterpeneIn this paper, we studied the oxidation degradation reactions between ocimene, myrcene, linalool and ozone, respectively. And we discussed the secondary reaction in the presence of O2, NO and H2O. It also studies the reaction trend in the liquid phase. At298K, the rate constant of ocimene, myrcene, linalool are7.19×10-16,3.51×10-19and3.83×10-16cm3molecule-1s-10更多还原