Studies On Nitrate Acid Based Imidazolium Ionic Liquids:Synthesis,Properties And Application In Desulfurization Of Oil

With increasingly stringent environmental regulations,our vehicle fuel quality requirements are more stringent.Currently,the production of low-sulfur "clean fuel"has become an inevitable trend.How to reduce the sulfur content of the oil has become an urgent and important task.Countries are stepping up research new fuel oil hydrodesulfurization technology,and the application of electrochemical technology for deep desulfurization is one of the research focus.The electro-polymerization desulfurization method has broad prospects for development owing to its simple operation and non-pollution.In this paper,a series of 1-alkyl-3-methylimidazolium nitrate acid ionic liquids,[C2mim][NO3],[C3mim][NO3],[C5mim][NO3]and[C6mim][NO3]were synthesized by adopting the traditional two-step method,and the ionic liquids were characterized and verified by 1H-NMR.The densities and surface tension of 1-alky 1-3-methylimidazolium nitrate acid ionic liquids were measured,and physicochemical properties of ILs were obtained by calculation,such as the standard entropy,surface entropy,surface energy,lattice energy,molar enthalpies of vaporization etc.This paper verified the interstice model of ILs.The parameters of interstice model and the coefficients of thermal expansion of the ILs were calculated,and were in good agreement with the experiment values,which means the interstice model is reasonable.The experiment of electro-polymerization desulfurization were conducted with the synthesized ionic liquid[C5mim][NO3]and model oil.After the optimized condition experiment,the mass ratio between model oil and IL,electro-polymerization potential,temperature,reaction time,were confirmed.The orthogonal experiment analysis,and the best technological parameters were determined as:the mass ratio between model oil and IL was 3:1(mL),electro-polymerization potential was 2.8V,temperature was 85 ?,time was 150 mim.At last,this paper studied the desulfurization performance of the homologs of 1-alkyl-3-methylimidazolium nitrate acid ionic liquids[Cnmim][NO3](n=2,3,5,6).It showed that[C5mim][NO3]has the best desulfurization results among them,and with the length change of carbon chain in imidazolium molecular and the space steric effect,[C2mim][NO3],[C3mim][NO3]and[C6mim][NO3]have poor desulfurization performance relatively.On the one hand,The thesis made a deep research on the nature of the nitric acid imidazole ionic liquid;on the other hand,The thesis put forward the electrochemical method to do desulfurization for thiophene model oil,which made the ionic liquids as supporting electrolyte.The experiments not only enriched the ionic liquids in basic theoretical research and development of ionic liquids,but also provided a new idea in its field of application.