The Synthesis Of Metal Ions Based Ionic Liquids Immobilized On SBA-15 And The Application In Desulfurization

With the global environmental pollution,many countries have carried out a series of more stringent environmental protection laws and regulations,especially on the sulfide content in petroleum products.The emission of SOx in fuels combustion process contributes to acid rains,greenhouse and air pollution,leading to serious environmental problems.So it is urgent to remove sulfides from fuels.The hydrodesulfurization(HDS)process is highly efficient in removing thiols,thioether and disulfides,but less effective for thiophenes and thiophene derivatives because of the steric hindrance.In view of the ionic liquids and metal ions are able to interact with the thiophene sulfide in mild conditions with ideal desulfurization efficiency.So in this paper,both the ionic liquid and the metal ion loaded on SBA-15 which as the carrier,and the functionalized SBA-15 adsorbents with "double activity center" were used for desulfurization,which providing a new way for design and synthesis of adsorption desulfurization agent.Firstly,1-(triethoxy-silylpropyl)-3-methylimidazolium chloride was synthesized,and then,both ionic liquids and metal ion loaded on mesoporous material SBA-15 by sol-gel method or two-step method.The synthesized samples were characterized by IR,XRD,N2 adsorption-desorption,elemental analysis,SEM,EDS,XRF and AAS.The results suggested that both the ionic liquid and the metal ion had been immobilized on SBA-15 with ordered two-dimensional hexagonal mesoscopic structure.Taking these functionalized SBA-15 samples synthesized by sol-gel as adsorbents,static desulfurization experiments for different sulfides were investigated.The results suggested that 3.2series adsorbents showed the best sulfide removal efficiency.The sulfur removal through adsorption process decreased in the order of DBT>BT>TS>2-MTS for each adsorbent and the desulfurization efficiency of different adsorbents increased in the order SBA-15<IL-SBA-15<Zn-IL-SBA-15.Static and dynamic adsorption desulfurization experiments were investigated by 3.2 series adsorbents.The static desulfurization experiments showed that time,temperature,the molar ratio of adsorbent to oil effected the S-removal efficiency.Under the defined dynamic desulfurization experiments conditions,thebreak-through time of Zn-3.2IL-SBA-15 on 2-methyl thiophene,thiophene,benzothiophene and dibenzothiophene was 50 min,10min,140 min,160min,and the break-through capacity was 0.362%,1.667%,2.070% and 3.687%,respectively.Recycle experiments showed the times of recycling utilization rate were limited,which need to be further improved.The adsorption equilibrium experiments at different temperature of Zn-3.2IL-SBA-15 on thiophene and benzothiophene were investigated,the adsorption experiments data were correlated by Henry,Langmuir,Freundlich models.Langmuir models fitted better,which suggested that the adsorption of thiophene and benzothiophene were prone to uniform monolayer adsorption.The thermodynamic calculation results showed that the adsorption was a process of randomness decreased,exothermic physisorption,and thiophene and benzothiophene adsorbed on Zn-3.2IL-SBA-15 inclined to parallel.?complexation,?-? complexation and electrostatic attraction could explain the adsorption mechanism of functioned SBA-15 and aromatic sulfides.In order to improve the load rate of two kinds of active center,two-step method was used to synthetize the functioned SBA-15 by ionic liquids and metal.The experimental results suggested that,although it can increase the load rate of metal ions or ionic liquids by two-step method,the S-removal efficiency was not high,and the suitable proportion of raw material need further exploration.