| 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. |
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