EA034199B1 - Improved method of producing nitrogen oxide(iv) - Google Patents

Abstract

The invention relates to an improved method to synthesize nitrogen oxide(IV) NOand can be used in the field of non-organic and organic chemistry and in realizing in a generator of rocket propellent oxidizer of NTO grade. To produce nitrogen oxide(IV) NO, a reaction is run between the nitric acid and acetic anhydride or a mixture of the nitric acid and acetic anhydride at the volume ratio of the acetic anhydride 4.76-100%.

Description

The invention relates to the field of inorganic and organic chemistry, as well as to the field of rocket science, i.e. to dual-use technologies. Nitric oxide (TU) NO ₂ is used in the synthesis of organic nitro compounds (nitroalkanes, nitroalkenes, starch nitroesters, etc.) [1-5], nitroso compounds [1], nitrosyl sulfuric acid, nigrosine perchlorate, preparation of anhydrous metal nitrates, insect attractant [6] as well as an agent for accelerated corrosion testing of metals, dissociating heat carrier or solvent.

The invention describes an improved method for producing nitric oxide (TU) NO ₂ and is intended to be implemented in an improved NTO rocket fuel oxidizer generator for operation in Russia (Siberia) or in the USA (Alaska), i.e. at temperatures below 16.75 ° C and to the freezing temperature of the nitric acid azeotrope (about -40 ° C).

The literature describes the Kleiner method [7, 8] and the inverse Kleiner method [9], which can be considered as analogues of the claimed invention. The Kleiner method is based on the decomposition of nitrous acid salts, and the inverse Kleiner method is based on the redox reaction of calcium nitrite with ascorbic acid. In both cases, NO gas is also formed, which must be oxidized with oxygen (atmospheric oxygen). The Kleiner method and the inverse Kleiner method give a large amount of liquid waste, which does not allow us to consider them as promising for industrial implementation.

There is also a method for producing high-quality anhydrous nitric oxide (TU) NO2 by boiling a solution of sulfuric and nitric acids using acetic acid as a reducing agent [10] with an optimal ratio of acid volumes of 80: 40: 6. The method allows to obtain the target product with a high yield and 100% conversion of nitric acid. This method is selected as a prototype of the claimed invention.

The disadvantage of this method is the high freezing point of acetic acid (1 _cr = 16.75 ° C), which creates difficulties in implementing this technology in harsh climates, such as Siberia or Alaska, where the ambient temperature in winter can reach -40 ° C. Acetic acid frozen in the pipeline not only does not allow the generator to operate normally and to carry out the process under automation conditions, but will also disable it until the line of acetic acid is thawed into the mixing tank of the reagents.

The objective of the present invention is to provide a modified and improved method for the synthesis of nitric oxide (TU) NO2, which allows the NTO propellant oxidizer generator to operate at low temperatures in the harsh climate of Russia and other countries while maintaining all the other characteristics of the original prototype (high yield, regeneration waste solution).

The technical result of the invention is the refusal to heat the supply pipe of the reducing reagent to the mixing tank of the reactants in the rocket fuel oxidizer generator during the production of nitric oxide (TU) at ambient temperatures below the freezing temperature of pure acetic acid, and at a certain ratio of reactants and at temperatures below 0 ° C using a mixture of acetic acid and acetic anhydride.

This problem is solved due to the fact that as a reducing agent use a mixture of acetic acid and acetic anhydride with a volume fraction of acetic anhydride 4.76-100%. The redox reaction with acetic acid can be described by the equation:

HNO ₃ + CH ₃ COOH = 6 NO2 + 5 H ₂ O + CO + CO ₂ , and in the case of acetic anhydride the reaction will formally take the form

HNO ₃ + (CH ₃ CO) ₂ O = 12 NO2 + 9 H ₂ O + 2 CO + 2 CO ₂ .

All the characteristics of the claimed improved method for producing nitric oxide (TU) (an oxidizer of rocket fuel) are almost identical to the claimed method [10].

Methods for producing nitric oxide (TU) NO2 are given in the examples. All work must be carried out in a laboratory cabinet with an exhaust hood and all precautionary measures when working with carbon monoxide!

Example 1

Take 80 ml of a solution of H ₂ SO ₄ (ω = 94%), 40 ml of a solution of HNO ₃ (ω = 59%) and 6 ml of a solution containing a mixture of glacial acetic acid and acetic anhydride in a ratio of 1.0: 0.05. The mixture is stirred in a 250 ml flask, heated and boiled until the formation of NO _{2 is complete} . The spent solution is distilled to 80 ml and reused in the reaction. The total yield of liquid and gaseous nitric oxide (TU) NO2 is 99-100%.

Example 2

Take 80 ml of a solution of H ₂ SO ₄ (ω = 94%), 40 ml of a solution of HNO ₃ (ω = 59%) and 6 ml of acetic anhydride. The mixture is stirred in a 250 ml flask, heated and boiled until the formation of NO2 is complete. The spent solution is distilled to 80 ml and reused in the reaction. The total yield of liquid and gaseous nitric oxide (TU) NO2 is 99-100%.

- 1 034199

Sources of information:

1. Shiri M., Zolfigol M.A., Kruger H. G., Tanbakouchian Z. Tetrahedron, 2010, Vol. 66, No. 47, p. 90779106.

2. Patent BY 8456. Butrim S.M., Yurkshtovich T.L., Bildyukevich T.D., Butrim N.S., Sidorenko G.I., Nedorezov V.L., Arviga I.I. MKI ³ С08В 31/18, 31/06, А61Р 9/00, publication date 30.06.2005.

3. Borodkin, G.I .; Shubin, V.G. Russ. Chem. Rev. 2001, vol. 70, No. 3, p. 211-230.

4. Shiri, M. Dinitrogen Tetroxide: N ₂ O ₄ , Synlett., 2006, No. 11, p. 1789-1790.

5. Fisher, J.W. The Chemistry of Dinitrogen Pentoxide in Nitro Compounds; VCH: New York, NY, 1990.

6. Patent US 20060042155. Nolen J. MKI A01M 1/22, A01M 1/02, A01M 1/06. Date of publication: 2.03.2006.

7. Inorganic laboratory preparations by G.G. Schlessinger, 12, 1962.

8. Patent US 20040028596. Kleiner B. Int. Cl ⁷ . C01B 21/20, Priority date: 08/12/2002.

9. Patent US 7288664. Kleiner B. Int. Cl ⁷ . C07D 307/62, Priority date: 03/30/2004.

10. Eurasian application No. 201700017. Rudakov D.A. IPC ⁷ СВВ 21/36, Eurasian Bulletin No. 4, 2018. Date of publication: 04/30/2018.

Claims (1)

CLAIM A method for the synthesis of nitric oxide (CCU), including boiling a solution of sulfuric and nitric acids with an organic reducing agent, characterized in that a mixture of acetic acid and acetic anhydride with a volume fraction of acetic anhydride of 4.76-100% is used as a reducing agent.