摘 要:本文综述了当前国内外汽油脱除烯烃的几项措施和机理研究。烯烃存在于汽油中会使油品稳定性下降、抗爆性能下降,烯烃在汽油运输存储过程中会发生聚合形成胶质类物质。胶质的形成不但会吸附在催化剂活性表面,造成失活,而且还会沉积于发动机中,影响发动机性能和汽车尾气的排放。当汽油中烯烃含量增加时,尾气中NOx和COx含量显著上升,而废气也会与挥发性有机物结合产生有毒化学烟雾和经太阳紫外线照射形成臭氧、甲醛、丙烯醛、过氧乙酰硝酸酯等产物,危害环境和人体健康。基于烯烃存在所带来的危害,国内外针对性地开发出一系列类脱烯烃方法,如白土精制、加氢精制、水合工艺、醚化工艺等,从而使汽油能够满足相应的燃油标准或规范。本文旨在综述各个汽油脱烯烃的反应机理与工艺特点,总结出我国汽油脱烯烃的主要原则:(1)大幅降低烯烃含量(2)较小损失辛烷值(3)活性氢消耗低、液收高55998
毕业论文关键词:汽油,脱烯烃,催化加氢
Abstract:This paper has described several measures and mechanism research at present gasoline olefin removal at home and abroad. Discovery the presence of olefins in gasoline will lower the stability of oil, anti-knock performance degradation, transport of olefins in gasoline storage process will polymerize to form substance classes. Substance classes will not only be adsorbed on the surface of the catalyst activity, resulting in inactivation, but deposited in the engine, the affect of engine performance and exhaust emissions. When the olefin content in gasoline increase, exhausted NOx and COx levels will increase significantly. While the exhaust gas will react volatile organic to produce toxic chemical fumes and ozone formed by solar ultraviolet radiation, acrolein, peroxyacetyl nitrate and other products. Which harm the environment and human health. For these harms caused by the presence of olefins, a series of de-olefins class methods have been developed, such as clay refining, hydro-treating, hydration process, etherification processes. This paper aimed to review the mechanism and characteristics of some technology to decrease gasoline olefin, and put off some main principles of to decrease the olefin of gasoline such as: (1) significantly reduced olefin content (2) minor damage octane number (3) active hydrogen consumption is low.
Keywords:gasoline, olefin removal, catalytic hydrogenation
目 录
1 前言 3
1.1燃料汽油的发展 3
1.2汽车工业对汽油的要求 4
1.3汽油脱除烯烃的意义 5
2 现有主要脱烯烃方法 5
2.1 白土精制 5
2.2 加氢精制 6
2.2.1工艺反应机理 6
2.2.2工艺流程和特点 7
2.2.3加氢精制研究进展 8
2.3 FCC汽油工艺脱除烯烃 8
2.3.1 FCC工艺原理 8
2.3.2 FCC流程 9
2.3.3催化汽油脱烯烃的措施 9
2.3.3.1原料的选择 9
2.3.3.2 工艺条件的改善 10
2.3.3.3 催化剂的选择 10
2.3.3.4脱烯烃工艺改造