| In the face of increasingly serious environmental pollution problems,the clean treatment of fuel products has important practical significance.The deep eutectic solvent（DES）has the incomparable advantages by comparison with the traditional extraction denitrification agent.In order to achieve deep denitrification of fuel,this paper designs three major DES systems,and DES’s synthesis and extraction mechanism are studied by combining theoretical calculations..A fatty alcohol or an aromatic alcohol is used as a hydrogen bond donor,and a quaternary ammonium salt is used as a hydrogen bond acceptor to synthesize a DES.The relations of the basic properties such as density,viscosity,and mutual solubility with components of the DES are studied.The DES is applied to the denitrification process of simulated gasoline.Two preferable extractants of[TBAC][ETA]2[TBAC][BBA]2 were characterized by FT-IR and 1H NMR techniques.The denitrification process was optimized:the ratio of agent to oil was 1:10,the extraction temperature was 30°C,the extraction time was 15 min,and the standing time was 1 h.The extraction efficiencies of two DESs on benzpyrole in the simulated oil were99.81%and 95.66%,respectively.After the extractant was regenerated by back extraction,there was no significant change in the repeated nitrogen removal for 6 times,and the recycling property was good.According to the density functional theory,the structure of the DES molecules is optimized to obtain the most stable configuration,and then the electrostatic potential and the reduced density gradient were analyzed for the most stable configuration.It is found that the intermolecular forces of the synthesized DESs are mainly hydrogen bonds,van der Waals forces,etc.,and these weak interaction forces also play an important role in the extraction and denitrification process.The DES was synthesized from furan methanol and quaternary ammonium salt,and the effects of different components and ratios of components on DESs’basic properties were studied.The extractant of[TBAC][FAL]2 with excellent denitrification performance was screened,and its structure was characterized by FT-IR and 1H NMR.The DES was applied to the process of removing non-alkaline nitrides of antimony and pyrrole from gasoline,and the denitrification process was optimized:the ratio of agent to oil was 1:10,the extraction temperature was 30°C,the extraction time was 15 min,and the standing time was 1 h.The rotation speed was 800 r/min,the extraction efficiency of the nitride pyrrole in the simulated oil was up to 97.17%,and the extraction efficiency of the antimony was up to 99.70%.After the extractant was regenerated by back extraction,it was reused 5 times and the denitrification efficiency was still above 90%.Combined with theoretical molecular simulation calculation,extraction denitrification process of DES molecules were calculated and analyzed.The research results show that hydrogen bond,van der Waals force and other weak forces are the main force of low temperature eutectic solvent formation and denitrification process.A series of DESs were synthesized from acid compounds and amide compounds.The relationship between the different components,ratios of components and extraction efficiencies of the formed DESs was investigated.The extractant[NMEA][DBPA]with excellent denitrification performance was screened,and its structure was characterized by FT-IR and 1H NMR techniques.The DES was applied to the denitrification process of gasoline for alkaline nitride and non-alkaline nitride,and the denitrification process was optimized:the ratio of agent to oil was 1:7,the extraction temperature was 30°C,the extraction time was 60 min,and the standing time was 1 h.The extraction efficiency of the extractant[NMEA][DBPA]on the nitride benzpyrole in the simulated oil was 83.78%and the extraction efficiency of the quinoline was 94.52%at 1 h and 800 r/min of the rotation speed.The synthesized DES has a significantly better extraction effect on the basic nitride in the simulated oil than the non-alkaline nitride.After the extractant was regenerated by back extraction,it still had good extraction performance after repeated use for 4 times.Combined with the simulation calculation and analysis of aromatic alcohol DES and furan methanol DES,the mechanism of extraction and denitrification of DES molecules was studied from molecular and atomic perspectives.In this paper,three types of deep eutectic solvent extractants were successfully synthesized to use in the denitrification process of simulated fuel,and by combining with quantum chemical calculation,the synthesis and extraction mechanism of deep eutectic solvent were studied.The study provides efficient,green,and new route for clean fuel. |
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