Preparation And Capabilities Of Nitric Oxide Deep Eutectic Absorbents

Coal plays a major role in China’s energy structure.The flue gas produced by coal combustion contains a large amount of nitrogen oxides,which causes great harm to the human body and the environment.Nitrogen oxides account for more than 90% of the nitrogen oxides.At present,many methods for removing nitric oxide have been proposed at home and abroad.However,these methods are difficult to meet the strict requirements of energy saving and environmental protection.Because of its special physical and chemical properties,such as simple synthesis and no pollution,deep eutectic solvents are expected to be used in the removal of nitric oxide.Therefore,this article takes nitric oxide and deep eutectic solvents as the main research object.In this paper,by screening hydrogen bond donors and hydrogen bond acceptors,benzoic acid / tetrabutylphosphine chloride(1:2)deep eutectic solvent and glycerol / 1-butyl-3 methylimidazole chloride(1:1)deep eutectic solvent were preferred.Through absorption experiments,repeated absorption-desorption experiments,thermogravimetric tests,absorption loss exploration,and carbon dioxide selectivity experiments,We explored the law of the saturated absorption rate of nitric oxide with temperature for two selected deep eutectic solvents,as well as their reusability,thermal stability,absorption process loss and carbon dioxide selectivity.The infrared spectroscopy and hydrogen nuclear magnetic spectroscopy were used to explore the nitric oxide absorption mechanism by two selected deep eutectic solvents,which was verified by gaussian simulation calculation.The experimental results show that both selected deep eutectic solvents have the higher absorption of nitric oxide than most of the deep eutectic solvents previously explored.Benzoic acid / tetrabutylphosphine chloride(1:2)deep eutectic solvent has the molar absorption of nitric oxide up to 2.75mol/mol;The molar absorption of glycerin / chlorinated 1-buty-3-methylimidazole salt(1:1)deep eutectic solvent to nitric oxide is 1.16 mol/mol,but the mass absorption is as high as 0.13 g/g.Both selected deep eutectic solvents have good reusability;the nitric oxide desorption rate is higher than 70%;it has the thermal stability to meet the requirements of temperature use;the absorption process has minimal loss;and the selectivity of nitric oxide is high.The mechanism investigation results prove that the deprotonation of benzoic acid and glycerin is the main reason for the absorption of nitric oxide.The developed deep eutectic solvents are simple to synthesize,pollution-free,and has high nitrogen monoxide absorption,which is of great significance for the development of nitrogen oxide absorbtion.