【作者】 张洁；

【导师】 那平；

【作者基本信息】 天津大学 ， 发酵工程， 2008， 硕士

【摘要】 随着世界经济的高速发展和多年来对资源的持续开发,低硫化石燃料日益枯竭,使得高硫燃料的开采使用成为必然;然而世界各国对低硫和超低硫燃油的需求却在不断增加。因此进行新型深度脱硫吸附剂的制备、表征,研究燃油体系中界面污染物吸附过程,对于降低燃油中硫含量,解决环境问题具有十分积极的意义。本文以蒙脱土（MMT）作为载体,采用溶胶-凝胶法,经过改性剂修饰及有机-无机共混修饰制备了几种改性蒙脱土吸附剂。利用XPS、FTIR等对其进行结构表征,在模拟汽油体系中考察吸附温度、平衡时间、吸附剂用量等因素对吸附效果的影响,并优化工艺条件。在最优反应条件下,验证亚稳态平衡理论在有机体系中的适用性;利用XRD、XPS、TEM、FT-IR等仪器对噻吩的吸附行为进行微观表征。苯基三甲基溴化铵改性（PTMAB）、200℃下3h热处理后的蒙脱土在60℃、2h的条件下吸附脱硫效果最佳。经过200℃热处理,降低了蒙脱土层间水的含量,提高了材料的疏水性;苯基三甲基溴化铵成功插层进入蒙脱土的硅酸盐片层间,增大了蒙脱土的层间距,提高了吸附容量。宏观试验验证亚稳态平衡理论同样适用于有机体系,存在明显的固体浓度效应和初始溶质浓度效应。FTIR、NMR微观表征显示,噻吩分子大部分进入了蒙脱土的片层之间,通过其上的H与蒙脱土片层的Al-O八面体、或者Si-O四面体等形成电子给体-受体化合物而吸附到苯基三甲基溴化铵改性蒙脱土上。对3种Cu²⁺修饰的苯基三甲基溴化铵改性蒙脱土及其吸附行为进行微观表征,发现Cu²⁺存在三种结构状态:以水合离子[Cu（H₂O）₄]²⁺的形式,通过交换吸附方式存在于蒙脱石层间;以[Cu（AlO）_n（H₂O）_n]^X的形式,通过专性吸附存在于蒙脱土的Al-O八面体空位;以[Cu（SiO）_n（H₂O）_n]^X的形式,通过专性吸附存在于Si-O四面体片的六方形孔洞中。更多还原

【Abstract】 With rapid development of world economy and continuous exploiture of resource for years, exploitation of high sulfur fuel is inevitable due to the fossil fuels with low sulfur are being depleted. It is important to environment problems solution by studying on the process of interface pollutants adsorption in fuel system, as well as preparation and characterization of new desulfurization adsorbent.Absorbents of organic modified montmorillonite, characterized by X-ray Photoelectron Spectroscopic （XPS）, FTIR, were developed by sol - gel and modification. To optimize the absorption of the desulfurization process, the reaction conditions, such as different modifiers, adsorption temperature, balance time and absorbent amount were test by carrying out experiments in a simulated fuel system. the applicability of MEA theory in thiophene- modified montmorillonite system was tested by macro-experiments; the absorption behavior of thiophene was characterized by X-Ray Diffraction（XRD）, XPS, Transmission Electron Microscopy （TEM）, Fourier transform infrared spectra （FT-IR）, Nuclear Magnetic Resonance （NMR）, etc. Finally, 3 kinds of Cu2+ modified PTMAB-MMT were developed to study the mechanism of absorption by performancing in thermodynamic tests and characterized by XRD, FT-IR, Electron Paramagnetic Resonance （EPR）, etc.The preparation of materials indicated that, the absorbent with best desulfurization performance was modified with phenyltrimethylammonium tribromide （PTMAB）, heat-treated by 200℃for 3 hours, absorbing in 60℃, 2 hours. the structure characterization of MMT showed that, 200℃heat treatment reduced the water content of MMT layer and improved the hydrophobicity of MMT; PTMAB was successfully inserted into the silicate layers of montmorillonite, which enlarged the interlayer space and improved the absorption capacity.MEA theory is applicable in the adsorption system of thiophene-modified MMT. There was obvious effect of solid concentration and initial concentration of solutes in this system. Micro-characterization indicated that, most thiophene molecular inserted into the internal layers of absorbent. It was absorbed into the PTMAB-MMT by forming a component of electron donor- electron accepter, which was produced by H of thiophene and the Al-O octahedron or Si-O tetrahedron of MMT layer.After characterized the modified MMT with Cu²⁺, 3 structures of Cu²⁺ were found in them: Cu²⁺ [Cu（H₂O）₄]²⁺ , hydrated ions, existed between the layers of MMT, and Cu²⁺ exists in the form of montmorillonite hexagon holes of Si-O tetrahedron or the spare space of Al-O octahedrone [Cu（AlO）_n（H₂O）_n]^X. The former belongs to the exchange adsorption, and the latter belongs to the specific adsorption, with two of which Cu²⁺ is able to insert MMT.更多还原