RU2669857C1 - Method of obtaining product for air regeneration - Google Patents

Abstract

FIELD: meeting human vital requirements.SUBSTANCE: invention relates to obtaining products for air regeneration for life support systems. To obtain the product for air regeneration, a mixture of hydrogen peroxide solution with magnesium sulfate and lithium and potassium hydroxides with subsequent dehydration of the obtained alkaline solution of hydrogen peroxide by spraying it in a drying agent flow. In this case, orthoboric acid is added to the hydrogen peroxide solution after the addition of magnesium sulfate at a molar ratio of hydrogen peroxide/orthoboric acid (HO/HBO) = 285–800. Lithium and potassium hydroxides are introduced simultaneously in two portions with an interval of 7–10 minutes so that the temperature in the synthesis zone does not exceed 40 °C.EFFECT: due to intensification of mass-exchange processes at the gas-liquid boundaries and liquid-solid phase, the degree of carbon dioxide product processing is increased for air regeneration when it is used in individual breathing apparatus, which ensures a reduction in the mass-dimensional parameters of the product.1 cl, 5 ex, 1 tbl

Description

The invention relates to methods for producing products for the regeneration of air based on potassium superoxide, used to protect human respiratory organs from damaging factors of a chemical and biological nature in individual breathing apparatus (IDA).

A known method of obtaining a product for air regeneration [RF patent No. 2596770 IPC A62D 9/00, 2016], as follows. Magnesium sulfate is introduced into a solution of hydrogen peroxide with a concentration of from 50 to 85% by mass with vigorous stirring. After it is completely dissolved (about 1-3 minutes), alkali metal tetraborates are introduced into the liquid phase, using lithium, sodium, potassium tetraborates or a mixture thereof, then lithium hydroxide and potassium hydroxide. Potassium hydroxide is introduced into the system 10-15 minutes after the introduction of lithium hydroxide. The molar ratio of the starting components should be as follows: hydrogen peroxide / magnesium sulfate (H ₂ O ₂ / MgSO ₄ ) = 450 ÷ 800; hydrogen peroxide / alkali metal tetraborate (H ₂ O ₂ / Me ₂ B ₄ O ₇ ) = 400 ÷ 700; hydrogen peroxide / lithium hydroxide (H ₂ O ₂ / LiOH) = 3.0 ÷ 15.0; hydrogen peroxide / potassium hydroxide (H ₂ O ₂ / KOH) = 1.60 ÷ 2.00. To reduce the kinetics of the decomposition of hydrogen peroxide, the addition of lithium and potassium hydroxides is carried out so that the temperature of the liquid phase of the ternary system MeOH - H ₂ O ₂ - H ₂ O (alkaline solution of hydrogen peroxide) does not exceed 25 ° C. The resulting alkaline solution of hydrogen peroxide is dispersed by a nozzle into the drying chamber in the direct flow of the drying agent, where it is dehydrated. A typical drying chamber with a nozzle is used. As a drying agent, air or any inert gas, for example nitrogen, is used. The temperature of the drying agent ranges from 120 to 300 ° C (preferably 180 ÷ 220 ° C). At the end of dehydration, the solid product is separated from the gas mixture using a conventional battery cyclone and bag filter and collected in a special container. Next, the resulting product is molded in various ways to give a certain geometric shape (granules, blocks, tablets, etc.).

However, the product for air regeneration, obtained in a known manner, is characterized by an insufficiently high degree of development of carbon dioxide, which leads to an increase in the weight and size parameters of individual breathing apparatus. The latter is extremely inconvenient during the operation of IDA by users who are forced to constantly wear them (for example, miners) due to the specifics of working conditions. In addition, this method is not economical and safe.

The objective of the invention is to develop a method for producing a product for the regeneration of air, having improved operational characteristics during its operation as part of individual breathing apparatus.

The technical result consists in obtaining a product for the regeneration of air having a high degree of development of carbon dioxide during its operation in individual breathing apparatus, which ensures a reduction in the overall dimensions of the product.

An additional technical result is to increase the efficiency and safety of the process.

The technical result is achieved by the fact that in the method for producing a product for air regeneration by mixing a hydrogen peroxide solution with magnesium sulfate and lithium and potassium hydroxides, followed by dehydration of the obtained alkaline hydrogen peroxide solution by spraying it in a stream of a drying agent into a hydrogen peroxide solution after mixing it with sulfate magnesium is introduced into orthoboric acid at a molar ratio of hydrogen peroxide / orthoboric acid (H ₂ O ₂ / N ₃ VO ₃ ) = 285 ÷ 800.

In this case, lithium and potassium hydroxides are introduced into the liquid phase simultaneously in two portions with an interval of 7-10 minutes so that the temperature in the synthesis zone does not exceed 40 ° C.

The invention allows to achieve the claimed technical result due to the following circumstances. As is well known to those skilled in the art of chemisorption processes, absorption from the gaseous phase of sorbate (CO ₂ ) occurs in a thin layer of the liquid phase formed on the surface of the chemisorbents. Often the limiting stage of chemisorption processes is the internal diffusion of sorbate molecules into the bulk of the liquid phase and the formation of ionized molecules in it that enter into chemical reactions. When neutralizing orthoboric acid with alkalis, orthoborates containing (BO ₃ ) ^3– ion are not formed in aqueous solutions, since orthoborates are almost completely hydrolyzed due to the too low formation constant [B (OH) ₄ ] ^- . In the solution tetraborates, metaborates and salts of other polyboric acids (nB ₂ O ₂ ⋅ mH ₂ O) that do not exist in the free state (and which for this reason cannot be introduced into the liquid phase in the form of the starting compounds) are formed, which is well known from the inorganic course chemistry [Karapetyants M.X. Drakin S.I. General and inorganic chemistry. M .: Chemistry 1994]. The presence in the liquid phase in the indicated amount of alkali metal salts of polyboric acids leads to a decrease in the viscosity of the surface film of an aqueous solution formed on the surface of the product for air regeneration, which leads to increased diffusion processes at the phase boundaries in the liquid phase and an increase in the solubility and ionization of carbon dioxide in an aqueous solution of a surface film. As a result, due to the intensification of mass transfer processes at the gas - liquid and liquid - solid phase boundaries, the degree of product development for air regeneration by carbon dioxide increases.

It should be noted that the interaction of hydrogen peroxide and alkali metal hydroxides under normal conditions is a pronounced exothermic process, accompanied by catalytic decomposition of peroxide products under the influence of hydroxide anions [U. Chamb, C. Setterfield, R. Wentworth. Hydrogen peroxide, - M .: Foreign literature, - 1958. - 578 p.] And the release of atomic oxygen. This not only leads to a decrease in the content of peroxide compounds in the synthesis product, but also creates an additional threat of an “oxygen” fire, which is almost impossible to localize. Therefore, it should be noted that the obtained alkaline solution of hydrogen peroxide at a temperature of 40 ° C for 8 hours (the duration of the technological cycle) loses no more than 0.28% of active oxygen, i.e. less than an alkaline hydrogen peroxide solution prepared using technological methods and the ratio of components described in RF patent No. 2596770, where an alkaline hydrogen peroxide solution at a temperature of 25 ° C for 8 hours (the duration of the technological cycle) loses 0.35% of active oxygen. Thus, it is absolutely appropriate to talk about increasing the stabilizing effect of ions present in an alkaline solution of hydrogen peroxide on the chemical stability of the liquid phase of the ternary system MeOH-H ₂ O ₂ -H ₂ O and increasing the safety of the process of obtaining a product for air regeneration. The mechanism of stabilization of various solutions of hydrogen peroxide is unknown [G.A. Seryshev. Chemistry and technology of hydrogen peroxide, - L .: Chemistry, -1984. - S. 182.]. Therefore, it is difficult to unambiguously assess the effect of a particular ion or their associates contained in a multicomponent solution on the stability of the system as a whole. Finding a stabilizer for a specific purpose is a task that can only be solved empirically. But it was noted that magnesium sulfate should be introduced into the hydrogen peroxide solution first, and after its dissolution, orthoboric acid should be introduced into the resulting solution, and alkali metal hydroxides should be introduced in two portions with an interval of 7-10 minutes.

In addition, the use of orthoboric acid allows you to speed up the process of preparing an alkaline solution of hydrogen peroxide and to prepare and store it during the production cycle at a lower temperature, which positively affects the efficiency of the method of obtaining a product for air regeneration.

A method of obtaining a product for air regeneration is as follows. Magnesium sulfate is introduced into a solution of hydrogen peroxide with a concentration of from 50 to 85% by mass with vigorous stirring. After it is completely dissolved (about 1-3 minutes), orthoboric acid is introduced into the liquid phase at a molar ratio of hydrogen peroxide / orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ ) = 285 ÷ 800, lithium hydroxide and potassium hydroxide. Lithium and potassium hydroxides are introduced into the system simultaneously in two portions with an interval of 7 ÷ 10 minutes so that the temperature in the reaction zone does not exceed 40 ° C. This mode allows you to level out the influence of the temperature factor on the decomposition of peroxide products. The obtained alkaline solution of hydrogen peroxide is dispersed by a nozzle into the drying chamber in the direct flow of a previously decarbonized drying agent, where it is dehydrated. A typical drying chamber with a nozzle is used. As a drying agent, air or any inert gas, for example nitrogen, is used. Decarbonization of the drying agent is carried out using any carbon dioxide scavenger. To reduce the consumption of the drying agent, it can be preliminarily dehydrated by passing through regenerated water absorbers such as zeolite, silicate, etc. The temperature of the drying agent varies from 120 to 300 ° C (preferably 180 ÷ 220 ° C). At the end of dehydration, the solid product is separated from the gas mixture using a conventional battery cyclone and bag filter and collected in a special container. Next, the resulting product is molded in various ways to give a certain geometric shape (granules, blocks, tablets, etc.) and placed in an IDA cartridge.

In examples 1-5 shows data on the receipt of the claimed method of a product for air regeneration.

Example 1

To 56.82 L of an aqueous 50% hydrogen peroxide solution, 150 g of magnesium sulfate (H ₂ O ₂ / MgSO ₄ = 800) are added with continuous stirring. After MgSO _{4 is} dissolved, after about 1 minute, 77.5 g of orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ = 800) is introduced into the liquid phase, then 0.8 kg of lithium hydroxide and 3.1 kg of solid 90% potassium hydroxide are simultaneously . About 7 minutes after the neutralization reaction and the uniform distribution of all introduced components throughout the volume of the liquid phase, 7.2 kg of lithium hydroxide (H ₂ O ₂ / LiOH = 3) and 28.0 kg of solid 90% potassium hydroxide (H ₂ O ₂ / KOH = 2.0). The addition of a second portion of alkalis is carried out in such a way that the temperature of the liquid phase does not exceed 40 ° C. After that, the solution is dispersed through the nozzle into the drying chamber, into which decarbonized, dried air is heated, heated to a temperature of 220 ° C. The flow rate of the solution through the nozzle is 155 ml / min. The consumption of the drying agent is 970 kg / h. 39.8 kg of product is obtained containing 67.9% KO ₂ , 7.5% KOH, 15.5% Li ₂ O ₂ , 3.8% LiOH, 4.3% H ₂ O, 0.65% lithium polyborates and potassium and 0.35% MgSO ₄ .

Example 2

To 51.7 L of an aqueous 50% hydrogen peroxide solution, 210 g of magnesium sulfate (H ₂ O ₂ / MgSO ₄ = 520) was added with continuous stirring. After dissolution of MgSO _4, after approximately 1.5 minutes, 94.0 g of orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ = 600) was introduced into the liquid phase, then simultaneously 0.44 kg of lithium hydroxide and 3.1 kg of solid 90% potassium hydroxide. About 8 minutes after the neutralization reaction was carried out and all introduced components were uniformly distributed throughout the volume of the liquid phase, 3.93 kg of lithium hydroxide (H ₂ O ₂ / LiOH = 5) and 28.0 kg of solid 90% potassium hydroxide (H ₂ O) were simultaneously added ₂ / KOH = 1.82). The addition of a second portion of alkalis is carried out in such a way that the temperature of the liquid phase does not exceed 40 ° C. Further, as in example 1. Receive 38.5 kg of a product containing 74.3% KO ₂ , 9.4% KOH, 9.2% Li ₂ O ₂ , 2.6% LiOH, 3.8% H ₂ O, 0.45% of lithium and potassium polyborates and 0.25% of MgSO ₄ .

Example 3

To 45.45 L of an aqueous 50% hydrogen peroxide solution, 160 g of magnesium sulfate (H ₂ O ₂ / MgSO ₄ = 600) are added with continuous stirring. After dissolution of MgSO _4, after approximately 1.5 minutes, 99.2 g of orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ = 500) are introduced into the liquid phase, then simultaneously 0.13 kg of lithium hydroxide and 3.1 kg of solid 90% potassium hydroxide. About 8 minutes after the neutralization reaction was carried out and all introduced components were uniformly distributed throughout the volume of the liquid phase, 1.15 kg of lithium hydroxide (H ₂ O ₂ / LiOH = 15) and 28.0 kg of solid 90% potassium hydroxide (H ₂ O ₂ / KOH = 1.6). The addition of a second portion of alkalis is carried out in such a way that the temperature of the liquid phase does not exceed 40 ° C. Further, as in example 1. Receive 36.2 kg of a product containing 78.9% KO ₂ , 13.2% KOH, 2.9% Li ₂ O ₂ , 0.5% LiOH, 3.6% H ₂ O, 0.54% of lithium and potassium polyborates and 0.36% of MgSO ₄ .

Example 4

To 27.23 L of an aqueous 85% hydrogen peroxide solution, 167 g of magnesium sulfate (H ₂ O ₂ / MgSO ₄ = 670) was added with continuous stirring. After dissolution of MgSO _4, after about 2 minutes, 165.2 g of orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ = 350) are introduced into the liquid phase, then simultaneously 0.32 kg of lithium hydroxide and 3.1 kg of solid 90% potassium hydroxide . Approximately 9 minutes after the neutralization reaction and the uniform distribution of all introduced components throughout the liquid phase, 2.87 kg of lithium hydroxide (H ₂ O ₂ / LiOH = 7) and 28.0 kg of solid 90% potassium hydroxide (H ₂ O ₂ / KOH = 1.86). The addition of a second portion of alkalis is carried out in such a way that the temperature of the liquid phase does not exceed 40 ° C. Further, as in example 1. Receive 37.6 kg of a product containing 76.3% KO ₂ , 12.2% KOH, 6.2% Li ₂ O ₂ , 1.5% LiOH, 3.2% H ₂ O, 0.3% lithium and potassium polyborates and 0.3% MgSO ₄ .

Example 5

To 48.9 L of an aqueous 50% hydrogen peroxide solution, 230 g of magnesium sulfate (H ₂ O ₂ / MgSO ₄ = 450) was added with continuous stirring. After dissolution of MgSO ₄ after about 3 minutes, 187.2 g of orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ = 285) are introduced into the liquid phase, then simultaneously 0.2 kg of lithium hydroxide and 3.1 kg of solid 90% potassium hydroxide . About 10 minutes after the neutralization reaction was carried out and all the introduced components were uniformly distributed throughout the volume of the liquid phase, 1.86 kg of lithium hydroxide (H ₂ O ₂ / LiOH = 10) and 28.0 kg of solid 90% potassium hydroxide (H ₂ O) were simultaneously added ₂ / KOH = 1.72). The addition of a second portion of alkalis is carried out in such a way that the temperature of the liquid phase does not exceed 40 ° C. Further, as in example 1. Receive 36.4 kg of a product containing 74.6% KO ₂ , 13.2% KOH, 6.0% Li ₂ O ₂ , 0.9% LiOH, 4.3% H ₂ O, 0.43% of lithium and potassium polyborates and 0.57% of MgSO ₄ .

The product for air regeneration obtained by the claimed method was tested in the cartridge of a serial individual breathing apparatus ShSS-T (TU VT 8.154.000), used by miners and rescuers, on the installation "Artificial lungs".

Tests on the installation "Artificial lungs" were carried out under the following conditions:

- pulmonary ventilation 35.0 ± 1 L / min

- volumetric supply of carbon dioxide 1.57 ± 0.03 L / min - humidity of the gas-air mixture,% 96-98

- breathing rate 20 ± 0.5 min ^-1

- ambient temperature 20-25 ° C

Volumes of oxygen and carbon dioxide are indicated at 10 ° C and 101.3 kPa,

pulmonary ventilation - at 37 ° C and 101.3 kPa.

For comparison, under the same conditions, a product was tested for air regeneration, specially manufactured by the method described in the patent of the Russian Federation No. 2596770 (example 5). All products for air regeneration had the form of granules of the same size and density. The time of the protective action of the IDA was determined as the time from the beginning of its operation to the moment when the concentration of CO ₂ in the stream of the gas-air mixture on the inspiration line of the Artificial Lungs reached 3%. The test results are presented in the table.

As can be seen from the data presented in the table, the product for air regeneration obtained according to the invention, by such important operational characteristics as the time of the protective action and the degree of exhaustion of carbon dioxide, exceeds similar indicators of the product for air regeneration obtained according to the patent of the Russian Federation No. 2596770.

The above positive aspects associated with the process of air regeneration in the IDA cartridge are due to the presence of polyboric acids in the product for air regeneration in the indicated amount of alkali metal salts and the method of their introduction into the product, which leads to a decrease in the viscosity of the surface film of an aqueous solution formed on the surface of the product . This, in turn, leads to an increase in diffusion processes at the phase boundaries in the liquid phase and to an increase in the solubility and ionization of the reacting substances in the aqueous solution of the surface film. As a result, due to the intensification of mass transfer processes at the gas - liquid and liquid - solid phase boundaries, the degree of carbon dioxide production of the product for air regeneration during its operation in individual breathing apparatus increases, which allows to reduce the product's overall dimensions.

This is especially true when using the product for air regeneration in the IDA of constant wear by users, due to the specifics of working conditions.

In addition, the presence in the alkaline solution of hydrogen peroxide in the indicated amount of alkali metal salts of polyboric acids and the sequence of introduction of the starting components into the liquid phase make it possible to reduce the preparation time of the alkaline hydrogen peroxide solution and to reduce the production of atomic oxygen during the production cycle, i.e. increase the safety and efficiency of the process.

Claims (1)

A method of obtaining a product for air regeneration by mixing a hydrogen peroxide solution with magnesium sulfate and lithium and potassium hydroxides, followed by dehydration of the obtained alkaline hydrogen peroxide solution by spraying it in a drying agent stream, characterized in that orthoboric is introduced into the hydrogen peroxide solution after mixing it with magnesium sulfate acid at a molar ratio of hydrogen peroxide / orthoboric acid (H ₂ O ₂ / H ₃ BO ₃ ) = 285-800, while lithium and potassium hydroxides are introduced into the liquid phase simultaneously in two portions mi with an interval of 7-10 minutes. so that the temperature in the synthesis zone does not exceed 40 ° C.