【作者】 李凯；

【导师】 曾勇平；

【作者基本信息】 扬州大学 ， 化学工程与技术， 2019， 硕士

【摘要】 燃料油具有高能量密度的重要能源,并且已广泛应用于车辆,燃料电池和发电机等。然而,碳氢化合物燃料中的有害物质,尤其是硫和氮化合物,在化学转化后对环境造成危害,导致人类严重的呼吸系统疾病。因此,希望通过工艺技术上的改进,生产具有低硫和氮含量的燃料。传统的加氢脱硫(HDS)已被广泛用于去除硫化合物。然而,HDS反应条件苛刻,耗费大量氢气,难以除去芳香族硫化物,并会降低燃料的辛烷值。吸附脱硫(ADS)作为一种非加氢脱硫手段,操作条件温和、设备投资较少、能源消耗较低、操作简单易行。此外,脱硫用吸附剂能够再生且不会降低油品辛烷值,在深度脱硫领域受到广泛关注。金属有机骨架材料(MOFs)作为一种新型多孔材料,具有比表面积大、孔隙率高、孔道尺寸可调等优点在吸附脱硫领域得到科研人员的重视。本文以 Cu2+为金属中心,均苯三甲酸(H3BTC)为有机配体合成[(CH3)NH2]3[(Cu4CL)3(BTC)8]·9DMA(BTC=1,3,5-均苯三甲酸,DMA=N,N-二甲基乙酰胺),简称Cu-BTC-DMA。通过水热合成引导Cu-BTC-DMA晶体在层状氧化石墨烯(GO)上生长,形成Cu-BTC-DMA/GO复合材料,加入GO的量不同,复合材料的生长结构出现较大差异。在以噻吩为硫化物,正辛烷为溶剂的模拟油中,分别通过静态和动态吸附测试吸附剂的脱硫性能,并研究材料的再生性能。静态吸附实验表明:Cu-BTC-DMA/GO(5%)对噻吩的吸附量最好,在这些材料中按照吸附量的大小排序为Cu-BTC-DMA/GO(5%)>Cu-BTC-DMA/GO(1%)>Cu-BTC-DMA/GO(10%)>Cu-BTC-DMA。动态吸附实验结果与静态吸附吻合,验证了加入5%的GO为最佳引入量。Cu-BTC-DMA/GO(5%)材料经过一次再生后的吸附量为新鲜吸附剂的85.6%。将10 nm Fe304纳米颗粒在预制备过程中加入到Cu-BTC-DMA晶体的制备原材料中,合成了一种新型的嵌入式结构Cu-BTC-DMA/Fe304复合材料作为吸附脱硫的固体吸附剂。通过TEM图像可以清晰地看出Fe304颗粒嵌入到Cu-BTC-DMA微米级正八面体晶体内部。N2吸脱附测试表明Cu-BTC-DMA/Fe304复合材料相比于Cu-BTC-DMA增加了中孔。静态吸附实验表明:由于复合材料中Fe304纳米颗粒含量较小(质量含量2.5%)且Cu-BTC-DMA晶体结构没有遭到破坏,因此吸附脱硫容量与Cu-BTC-DMA相当。复合材料相比于Cu-BTC-DMA增加了中孔,使得复合材料对苯并噻吩的吸附量远大于Cu-BTC-DMA。Cu-BTC-DMA/Fe304复合材料由于有效分离,几乎没有减重。使用后的吸附剂经过5次循环再生后,噻吩的吸附量保持新鲜吸附剂吸附量的93.2%。证明材料具有良好的再生性能。以Fe3+为金属中心,对苯二甲酸(H2BDC)为配体合成MIL-53(Fe)。通过分层包裹法将MIL-53(Fe)包裹在硅烷化后的Fe304纳米颗粒表面形成具有核壳结构的MIL-53(Fe)/Fe304复合材料。通过TEM图像可以清晰地观察到MIL-53(Fe)晶体生长在200 nm的Fe304颗粒表面。静态吸附实验则表明了 MIL-53(Fe)/Fe304复合材料对噻吩仍然具有良好的选择性。此外复合材料由于拥有磁响应性具有较高的回收率,在经过6次循环再生后,其吸附量仍然能达到新鲜吸附剂的94.9%,MIL-53(Fe)/Fe304复合材料具有良好的再生性。更多还原

【Abstract】 Fuel oil is an important energy source with high energy and high density,and has been widely used in vehicles,fuel cells and generators.However,harmful substances in hydrocarbon fuels,especially sulfur and nitrogen compounds,can cause environmental hazards after chemical conversion,and may also lead to serious respiratory diseases.Therefore,we hope to produce fuel with low sulfur and nitrogen content in industry through economic technology.Traditional hydrodesulfurization(HDS)has been widely used to remove sulfur compounds.However,HDS reaction conditions are harsh and consume a lot of hydrogen,which makes it difficult to remove aromatic sulfides and reduce fuel octane number.Adsorptive desulfurization(ADS),as a non-hydrodesulfurization method,has attracted much attention in the field of deep desulfurization due to its mild operating conditions,less investment in equipment,low energy consumption,simple operation,regeneration of adsorbents without reducing the octane number of oil products As a new porous material,metal organic frameworks(MOFs)have attracted wide attention in the field of adsorption and desulfurization due to its large specific surface area,high porosity and adjustable pore size.Cu2+ was used as the metal center and pyromellitic acid(H3BTC)was used as organic ligand to synthesize[(CH3)NH2]3[(Cu4CI)3(BTC)8]·9DMA(BTC=1,3,5-pyromellitic acid,DMA=N,N-dimethylacetamide),referred to as Cu-BTC-DMA.The growth of Cu-BTC-DMA crystals on layered graphene oxide(GO)was guided by hydrothermal synthesis to form Cu-BTC-DMA/GO composites.The growth structure of the composites varied with the amount of GO added.In the simulated oil with thiophene as sulfide and n-octane as solvent,the desulforization performance of adsorbent was tested by static and dynamic adsorption,and the regeneration performance of the adsorbent was studied.Static adsorption experiments showed that copper-BTC-DMA/GO(5%)had the best adsorption capacity for thiophene.The order of adsorption capacity was Cu-BTC-DMA/GO(5%)>Cu-BTC-DMA/GO(1%)>Cu-BTC-DMA/GO(10%)>Cu-BTC-DMA/GO(10%).The experimental results of dynamic adsorption are in agreement with static adsorption,and it is verified that 5%GO is the best amount of GO The adsorption capacity of Cu-BTC-DMA/GO(5%)material after one regeneration is 85.6%of fresh adsorbent,and the regeneration performance is generalA new embedded structure of Cu-BTC-DMA/Fe3O4 composite material was synthesized by adding 10 nm Fe3O4 nanoparticles into the raw materials of the preparation of Cu-BTC-DMA crystal in the pre-preparation process.It can be clearly seen from TEM images that Fe3O4 particles are embedded in the Cu-BTC-DMA crystal.N2 adsorption and desorption tests show that the mesoporous content of Cu-BTC-DMA/Fe3O4 composite is higher than that of Cu-BTC-DMA.Static adsorption experiments show that the desulfurization capacity of the composite is equal to that of Cu-BTC-DMA.The adsorption capacity of benzothiophene on the composites is much larger than that of Cu-BTC-DMA.Cu-BTC-DMA/Fe3O4 composites have little weight loss due to effective separation.After five cycles,the adsorption capacity of thiophene remained 93.2%of that of fresh adsorbent.It is proved that the material has good regeneration performance.MIL-53(Fe)was synthesized with Fe3+as the metal center and terephthalic acid(H2BDC)as the ligand.MIL-53(Fe)/Fe3O4 composite with core-shell structure was formed by coating MIL-53(Fe)on the surface of silylated Fe3O4 nanoparticles by layered encapsulation method.The growth of MIL-53(Fe)crystal on the surface of Fe3O4 particles at 200 nm can be clearly observed by TEM images.Static adsorption experiments show that MIL-53(Fe)/Fe3O4 composites still have good selectivity for thiophene.In addition,due to the high recovery of magnetic response,the adsorption capacity of the composite can still reach 94.9%of the fresh adsorbent after six cycles of regeneration.The good regeneration performance of MIL-53(Fe)/Fe3O4 composite lays the foundation for its industrial application.更多还原