An EDTA-based composite solid organic acid, its preparation method, and its application as an inhibitor of hydrogen production in the aluminum molten metal reaction.

Abstract

This invention provides an EDTA composite solid organic acid, its preparation method, and its application as an inhibitor of hydrogen production in the aluminum molten metal reaction, relating to the field of chemical reagents and their applications. The EDTA composite solid organic acid provided by this invention comprises EDTA and a solid organic carboxylic acid, wherein the mass content of the solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%. The EDTA composite solid organic acid provided by this invention can inhibit the production of hydrogen gas in the aluminum molten metal reaction. As an inhibitor of hydrogen production in the aluminum molten metal reaction, it exhibits good hydrogen inhibition effect, with an inhibition rate of over 85% after 100 hours of reaction. Furthermore, the process is simple and low-cost.

Description

Technical Field

[0001] This invention relates to the field of chemical reagents and their application technology, and in particular to an EDTA composite solid organic acid, its preparation method, and its application as an inhibitor of hydrogen production in the aluminum-water reaction. Background Technology

[0002] Solid rocket engines typically have a propellant storage life of around 10 years. Retired or expired solid rocket engines not only occupy inventory space but also pose significant safety and environmental hazards. Traditional solid rocket engine disposal methods usually involve complete destruction, such as incineration, burial, or deep-sea dumping. These methods pollute the environment, waste resources, and pose certain safety risks. To achieve the recycling and resource utilization of the engine casing and propellant charge, high-pressure water jet cutting technology is commonly used to safely separate the solid propellant charge from the engine casing. However, in engineering applications, several ignition or explosion accidents have occurred both domestically and internationally.

[0003] Aluminum powder is the most widely used metallic fuel in solid propellants, accounting for approximately 5-20% of their content. When solid propellants are cut using high-pressure water jets, the aluminum powder comes into contact with water, releasing hydrogen gas and a significant amount of heat. Chinese patent CN106672900A mentions that hydrogen gas is produced when aluminum powder and water are in a mass ratio of 1:150 to 1:40 and the water bath temperature is 70-90°C. Hydrogen production via the aluminum-water reaction is a simple, inexpensive, high-yield, safe, and environmentally friendly method, making it an economical and efficient hydrogen production approach. However, the accumulation of hydrogen gas may pose safety risks; therefore, suppressing hydrogen generation from aluminum powder during solid propellant processing is a key issue that needs to be addressed. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an EDTA composite solid organic acid, its preparation method, and its application as an inhibitor of hydrogen production in the aluminum molten metal reaction. The EDTA composite solid organic acid provided by this invention can inhibit the production of hydrogen gas in the aluminum molten metal reaction, and has a good hydrogen inhibition effect.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides an EDTA composite solid organic acid, comprising EDTA and solid organic carboxylic acid, wherein the mass content of solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%.

[0007] Preferably, the solid organic carboxylic acid includes one or more of citric acid, oxalic acid, nicotinic acid, and tartaric acid.

[0008] Preferably, the mass content of solid organic carboxylic acid in the EDTA composite solid organic acid is 25-75%.

[0009] This invention provides a method for preparing the EDTA composite solid organic acid described in the above technical solution, comprising the following steps:

[0010] EDTA and solid organic carboxylic acids are mixed to obtain the EDTA composite solid organic acid.

[0011] This invention provides the application of the EDTA composite solid organic acid described in the above technical solutions or the EDTA composite solid organic acid prepared by the above technical solutions as an inhibitor of hydrogen production from aluminum hydrate reaction.

[0012] Preferably, the method of application is as follows: adding the EDTA composite solid organic acid into the aluminum water reaction system.

[0013] Preferably, the aluminum in the aluminum molten metal reaction is aluminum powder, and the median particle size of the aluminum powder is 6-30 μm.

[0014] Preferably, the mass ratio of the aluminum to the EDTA composite solid organic acid is 1:1 to 1:10.

[0015] Preferably, the pH value of the mixed system composed of the EDTA composite solid organic acid and the aluminum water reaction system is 3 to 11.

[0016] Preferably, the temperature of the aluminum molten metal reaction is 10–90°C.

[0017] This invention provides an EDTA composite solid organic acid, comprising EDTA and a solid organic carboxylic acid, wherein the mass content of the solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%. In this invention, EDTA can form a complex with aluminum. The EDTA molecular chain has carboxyl and amino groups with strong coordination ability, which can form a highly stable soluble cyclic complex EDTA-Al with aluminum. However, the highest coordination number of aluminum is 6. The EDTA-aluminum complex does not reach the highest coordination number of aluminum. In the presence of other ligands, the uncoordinated complex easily forms a more stable, coordinate-saturated mixed complex. Therefore, EDTA easily forms mixed complexes with other solid organic carboxylic acids. This stable Al-organic complex hinders the transport of water molecules in the passivation film on the aluminum surface, thereby inhibiting the hydration process of the passivation film, prolonging the induction time of the aluminum-water reaction, and achieving the effect of hydrogen suppression. Furthermore, EDTA molecules have carboxyl and amino groups with strong coordination capabilities. The addition of solid organic carboxylic acids to the complex system enhances acidolysis, promoting the complete desorption of aluminum and increasing the EDTA's capture rate of metal ions. On the other hand, the solid organic carboxylic acid ions themselves also have a good complexing effect on metals. The EDTA composite solid organic acid provided by this invention can inhibit the production of hydrogen gas in the aluminum-water reaction. As an inhibitor of hydrogen production in the aluminum-water reaction, it exhibits good hydrogen suppression effects, with an inhibition rate of over 85% after 100 hours of reaction. Moreover, the EDTA composite solid organic acid provided by this invention is safe, environmentally friendly, and inexpensive, and the solid organic carboxylic acid within it is not easily volatile. Detailed Implementation

[0018] This invention provides an EDTA composite solid organic acid, comprising EDTA (ethylenediaminetetraacetic acid) and solid organic carboxylic acid, wherein the mass content of the solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%.

[0019] Unless otherwise specified, all raw materials involved in this invention are commercially available products well known in the art.

[0020] In this invention, the solid organic carboxylic acid preferably includes one or more of citric acid, oxalic acid, nicotinic acid and tartaric acid; the mass content of the solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%, preferably 25-75%, and more preferably 50-75%.

[0021] The EDTA composite solid organic acid provided by this invention, through the combination of EDTA and solid organic carboxylic acid, can inhibit the generation of hydrogen gas in the aluminum-water reaction, and has a good hydrogen inhibition effect.

[0022] This invention provides a method for preparing the EDTA composite solid organic acid described in the above technical solution, comprising the following steps:

[0023] EDTA and solid organic carboxylic acids are mixed to obtain the EDTA composite solid organic acid.

[0024] The present invention does not have any special requirements for the mixing method; any method known to those skilled in the art can be used to mix the mixture evenly.

[0025] This invention provides the application of the EDTA composite solid organic acid described in the above technical solutions or the EDTA composite solid organic acid prepared by the above technical solutions as an inhibitor of hydrogen production from aluminum hydrate reaction.

[0026] In this invention, the preferred method of application is to add the EDTA composite solid organic acid to the aluminum-water reaction system; when the EDTA composite solid organic acid is used to suppress hydrogen production from aluminum during solid propellant treatment, it is preferable to add the EDTA composite solid organic acid to water and use the resulting mixture to break up the solid propellant so as to separate the solid propellant charge from the engine casing.

[0027] In this invention, the aluminum in the molten aluminum reaction is aluminum powder, and the median particle size of the aluminum powder (i.e., d) 50 The particle size is preferably 6 to 30 μm, more preferably 10 to 15 μm.

[0028] In this invention, the mass ratio of aluminum to EDTA composite solid organic acid is preferably 1:1 to 1:10, and more preferably 1:2 to 1:5.

[0029] In this invention, the pH value of the mixed system composed of the EDTA composite solid organic acid and the aluminum water reaction system is preferably 3 to 11. In the embodiments of this invention, the pH value of the mixed system is 3 to 5.

[0030] In this invention, the temperature of the aluminum molten metal reaction is preferably 10-90°C, and more preferably 55-75°C.

[0031] In this embodiment of the invention, the hydrogen suppression effect of the EDTA composite solid organic acid was evaluated through the following experiments:

[0032] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (i.e. the temperature of the aluminum water reaction), preheat for 10 minutes, and adjust the speed to 200 r / min; pour water into the conical flask and keep it at a constant temperature in the water bath.

[0033] (2) After the temperature is constant, aluminum powder and the EDTA composite solid organic acid are added to the conical flask in sequence, the rubber stopper is quickly sealed, and hydrogen is collected by water displacement. The hydrogen suppression effect is evaluated by the amount of hydrogen generated.

[0034] In this invention, the water in step (1) is preferably distilled water, and the mass ratio of aluminum powder to water is preferably 1:50 to 1:200, more preferably 1:100 to 1:200; the mass ratio of aluminum powder to the EDTA composite solid organic acid is the same as in the above technical solution, and will not be repeated here. In this invention, the addition of the EDTA composite solid organic acid in step (2) can be done by adding the solid organic carboxylic acid and EDTA separately, or by mixing the solid organic carboxylic acid and EDTA first, and then adding them.

[0035] The evaluation results of hydrogen suppression effect show that the EDTA composite solid organic acid provided by the present invention has a good hydrogen suppression effect as an inhibitor of hydrogen production in aluminum water reaction. The hydrogen suppression effect is more than 85% after 100 hours of reaction.

[0036] To further illustrate the present invention, the following detailed description, in conjunction with examples, illustrates the EDTA composite solid organic acid provided by the present invention, its preparation method, and its application as an inhibitor of hydrogen production in the aluminum-water reaction. However, these descriptions should not be construed as limiting the scope of protection of the present invention.

[0037] Comparative Example 1

[0038] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0039] (2) Add 0.5g of aluminum powder (d 50 Particles with a diameter of 13 μm were poured into an Erlenmeyer flask, and the flask was quickly sealed with a rubber stopper. Hydrogen was collected by water displacement. The amount of hydrogen produced after 100 hours of reaction was 578 mL.

[0040] The generation of hydrogen gas in experimental step (2) is continuous.

[0041] Example 1

[0042] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0043] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.75g of citric acid and 0.25g of EDTA (citric acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0044] In step (2), an EDTA complex solid organic acid inhibitor was added. No hydrogen was generated in the first 4 hours of the reaction. After 100 hours of reaction, the amount of hydrogen was 50 mL. Compared with the method of Comparative Example 1 without any inhibitor, the hydrogen inhibition effect of Example 1 after 100 hours of reaction was 91.3% (calculated as (578 mL - 50 mL) / 578 mL).

[0045] Example 2

[0046] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0047] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.5g of citric acid and 0.5g of EDTA (citric acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0048] In experimental step (2), an EDTA composite solid organic acid inhibitor composed of citric acid and EDTA was added. No hydrogen was generated in the first 4 hours of the reaction. After 100 hours of reaction, the amount of hydrogen was 18 mL. Compared with the method of Comparative Example 1 without any inhibitor, the inhibition effect of Example 2 on hydrogen was 96.8% after 100 hours of reaction.

[0049] Comparative Example 2

[0050] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0051] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 1g of citric acid (with a particle size of 13μm) to an Erlenmeyer flask, quickly seal it with a rubber stopper, and collect hydrogen gas by water displacement. After 100h of reaction, the amount of hydrogen gas generated is 150mL.

[0052] Comparative Example 3

[0053] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0054] (2) Add 0.5g of aluminum powder (d) sequentially. 501 g of EDTA (particle size 13 μm) was added to an Erlenmeyer flask, and the flask was quickly sealed with a rubber stopper. Hydrogen was collected by water displacement. After 100 h of reaction, the amount of hydrogen produced was 107 mL.

[0055] Example 3

[0056] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0057] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.25g of nicotinic acid and 0.75g of EDTA (nicotinic acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0058] In experimental step (2), EDTA composite solid organic acid inhibitor was added. No hydrogen was generated in the first 5 hours of the reaction. After 100 hours of reaction, the amount of hydrogen generated was 10 mL. Compared with the method of Comparative Example 1 without any inhibitor, the inhibition effect of Example 3 on hydrogen was 98.3% after 100 hours of reaction.

[0059] Comparative Example 4

[0060] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0061] (2) Add 0.5g of aluminum powder (d) sequentially. 50 The hydrogen gas was collected in a conical flask containing 1g of nicotinic acid (particle size 13μm) and quickly sealed with a rubber stopper. The hydrogen gas was collected by water displacement. After 100 hours of reaction, the amount of hydrogen gas generated was 140mL.

[0062] Example 4

[0063] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 minutes, and adjust the speed to 200 r / min; pour 100 ml of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 minutes.

[0064] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.25g of oxalic acid and 0.75g of EDTA (oxalic acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0065] In experimental step (2), EDTA composite solid organic acid inhibitor was added. No hydrogen was generated in the first 3 hours of the reaction. After 100 hours of reaction, the amount of hydrogen generated was 86 mL. Compared with the method of Comparative Example 1 without any inhibitor, the hydrogen inhibition effect of Example 4 after 100 hours of reaction was 85.1%.

[0066] Comparative Example 5

[0067] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0068] (2) Add 0.5g of aluminum powder (d) sequentially. 50 1 g of oxalic acid (with a particle size of 13 μm) was added to an Erlenmeyer flask, and the flask was quickly sealed with a rubber stopper. Hydrogen gas was collected by water displacement. After 100 h of reaction, the amount of hydrogen gas generated was 434 mL.

[0069] Example 5

[0070] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (55℃), preheat for 10 min, and adjust the speed to 200 r / min. Pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0071] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.25g of tartaric acid and 0.75g of EDTA (tartaric acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0072] In experimental step (2), EDTA composite solid organic acid inhibitor was added. No hydrogen was generated in the first 5 hours of the reaction. After 100 hours of reaction, the amount of hydrogen generated was 58 mL. Compared with the method of Comparative Example 1 without any inhibitor, the hydrogen inhibition effect of Example 5 after 100 hours of reaction was 89.9%.

[0073] Comparative Example 6

[0074] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (75℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0075] (2) Add 0.5g of aluminum powder (d 50 Particles with a diameter of 13 μm were poured into an Erlenmeyer flask, and the flask was quickly sealed with a rubber stopper. Hydrogen was collected by water displacement. The amount of hydrogen produced after 100 hours of reaction was 644 mL.

[0076] The generation of hydrogen gas in experimental step (2) is continuous.

[0077] Example 6

[0078] (1) Set the heat-collecting constant temperature magnetic stirrer to the experimental temperature (75℃), preheat for 10 min, and adjust the speed to 200 r / min; pour 100 mL of distilled water into the conical flask and keep it at a constant temperature in the water bath for 10 min.

[0079] (2) Add 0.5g of aluminum powder (d) sequentially. 50 Add 0.25g of nicotinic acid and 0.75g of EDTA (nicotinic acid and EDTA form an EDTA complex solid organic acid inhibitor) to an Erlenmeyer flask with a particle size of 13μm, quickly seal the flask with a rubber stopper, and collect hydrogen gas by water displacement.

[0080] In experimental step (2), EDTA composite solid organic acid inhibitor was added. No hydrogen was generated in the first 2 hours of the reaction. After 100 hours of reaction, the amount of hydrogen generated was 95 mL. Compared with the method of Comparative Example 6 without any inhibitor, the hydrogen inhibition effect of Example 6 after 100 hours of reaction was 85.2%.

[0081] As can be seen from the above embodiments, the EDTA composite solid organic acid provided by the present invention has a good hydrogen inhibition effect as an inhibitor of hydrogen production in aluminum water reaction, and the hydrogen inhibition effect is more than 85% after 100 hours of reaction.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. The application of an EDTA composite solid organic acid as an inhibitor of hydrogen production in the aluminum-water reaction, wherein the EDTA composite solid organic acid comprises EDTA and solid organic carboxylic acid, and the mass content of the solid organic carboxylic acid in the EDTA composite solid organic acid is 1-99%.

2. The application according to claim 1, characterized in that, The solid organic carboxylic acids include one or more of citric acid, oxalic acid, nicotinic acid, and tartaric acid.

3. The application according to claim 2, characterized in that, The mass content of solid organic carboxylic acids in the EDTA composite solid organic acid is 25-75%.

4. The application according to any one of claims 1 to 3, characterized in that, The preparation method of the EDTA composite solid organic acid includes the following steps: EDTA and solid organic carboxylic acids are mixed to obtain the EDTA composite solid organic acid.

5. The application according to claim 1, characterized in that, The method of application is as follows: the EDTA composite solid organic acid is added to the aluminum water reaction system.

6. The application according to claim 1 or 5, characterized in that, The aluminum in the aluminum molten metal reaction is aluminum powder, and the median particle size of the aluminum powder is 6~30μm.

7. The application according to claim 6, characterized in that, The mass ratio of the aluminum to the EDTA composite solid organic acid is 1:1 to 1:

10.

8. The application according to claim 5, characterized in that, The pH value of the mixed system composed of the EDTA composite solid organic acid and the aluminum water reaction system is 3~11.

9. The application according to claim 1, characterized in that, The temperature of the aluminum molten metal reaction is 10~90℃.