Separation purification method for green nitrating agent nitrogen pentoxide

Abstract

The invention discloses a separation and purification method of nitrogen pentoxide as a green nitrating agent, and belongs to the separation technique of the nitrogen pentoxide. The method 1 comprises the following steps: adding N2O4 to the solution of N2O5, N2O4 and HNO3, cooling and seeding out the N2O5, and determining the mass content of the N2O4 and the HNO3 in the N2O5; introducing the mixed gas of ozone and oxygen into the N2O5, removing residual N2O4, dissolving the N2O5 into CCl4, CHCl3, CH2Cl2 or CH3CN solvents, and adding NaF particles to adsorb and remove the residual HNO3 in the N2O5; and then vaporizing the solvents to obtain the solid N2O5 with above 99 percent of mass purity. The method 2 has the difference from the method 1 and comprises the following steps: firstly adding the N2O5 after being seeded out in the solvents and then introducing the mixed gas of the ozone and the oxygen. The invention has the advantages of convenient and simple process operation, high yield of N2O5; and N2O5 prepared can be directly applied to nitration reaction.

Description

technical field The invention relates to a separation and purification method of a green nitrating agent dinitrogen pentoxide, which belongs to the separation technology of dinitrogen pentoxide. Background technique Oxidation of N by electrochemical method or ozone 2 o 4 / HNO 3 N 2 o 5 / HNO 3 Mixed solution (containing a small amount of N 2 o 4 ), the solution cannot be directly applied to organic synthesis reactions, especially the nitrification reaction of nitrogen compounds and the nitrification reaction of acid-sensitive substances, and further separation and purification are required. The patent SU1089047 adopts cooling at -5~0°C containing 35-40wt% N 2 o 5 / HNO 3 solution such that N 2 o 5 and HNO 3 Precipitate out of solution at a mass ratio of 1:1, then sublimate N by reduced pressure 2 o 5 and condense on the surface of the cold body to separate pure N 2 o 5 solid. This method has a long flow, the process is too complicated, and due to the N 2 o ...

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Problems solved by technology

N obtained by electrolysis 2 o 5 / HNO 3 solution with HNO 3 Mainly, adopting this method will consume a large amount of NaF solids, and there will be a large amount of HF in the solution when the amount of NaF is insufficient, which will easily cause equipment corrosion; at the same time, the reaction between nitrogen pentoxide and NaF will be inevitable, reducing the amount of nitrogen pentoxide yield

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