Marine-resistant environment-friendly water-based film-forming foam extinguishing agent and preparation method thereof

Abstract

The application discloses a seawater-resistant environment-friendly water film forming foam extinguishing agent which is composed of the following components in percentage by weight: fluorine-containing surfactant 4-10%, hydrocarbon surfactant 5-20%, seawater-resistant foaming agent 5-20%, foam stabilizer 3-7%, cosolvent 2-6%, anti-freezing agent 15-25%, and the rest is pure water. The seawater-resistant environment-friendly water film forming foam extinguishing agent solves the technical problem that fluorocarbon surfactants used in the existing water film forming foam extinguishing agent are easy to cause harm to the ecological environment and human health.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fire-fighting foam extinguishing agent, and particularly relates to a seawater-resistant environment-friendly water film forming foam extinguishing agent and a preparation method thereof. BACKGROUND

[0002] The water film forming foam extinguishing agent (AFFF) is also called "light water" foam extinguishing agent, and is mainly used in the extinguishing agent of hydrocarbon fuel fire (B class fire). The AFFF is usually composed of fluorine surfactant, hydrocarbon surfactant and other additives.

[0003] The extinguishing mechanism of the AFFF mainly embodies in oxygen isolation and suffocation, radiation heat resistance and heat absorption and cooling. After the AFFF is applied to the surface of the combustible organic liquid, a water film is quickly formed along with the spreading of the foam on the liquid surface, which can effectively protect the foam and improve the sealing performance of the foam, so as to isolate the combustible material and the oxygen in the air.

[0004] The core component of the AFFF is the fluorine surfactant, and the production and use of the fluorine surfactant need to comply with the specifications of the Stockholm Convention on Persistent Organic Pollutants and relevant protocols. In the production of the existing AFFF, the fluorine surfactant is mostly selected from long-chain fluorocarbon surfactants with high surface activity, high thermodynamic and chemical stability, such as perfluorooctane sulfonate (PFOS), perfluorooctanoic acid ammonium (PFOA) and the like. However, the long-chain fluorocarbon surfactant has poor degradation performance and is a relatively difficult-to-decompose organic pollutant. In the actual extinguishing process, the long-chain fluorocarbon surfactant is decomposed by heat to release a variety of gaseous perfluoro and polyfluoroalkyl compounds (PFAS) with high pollution, or the long-chain fluorocarbon surfactant enters the surrounding environment along with the AFFF extinguishing agent liquid, thereby causing harm to the ecological environment and human health. Therefore, the production and use of the long-chain fluorocarbon compound are gradually restricted or even prohibited at home and abroad, and the long-chain fluorine surfactant applied in the field of extinguishing agent is also included in the list of prohibited and restricted use.

[0005] Therefore, it is necessary to develop a seawater-resistant environment-friendly water film forming foam extinguishing agent which is green, environmentally friendly and has good extinguishing effect. SUMMARY

[0006] The present application provides a seawater-resistant environment-friendly water film forming foam extinguishing agent to solve the technical problem that the fluorocarbon surfactant used in the existing water film forming foam extinguishing agent is easy to cause harm to the ecological environment and human health.

[0007] Therefore, the present application provides a seawater-resistant environment-friendly water film forming foam extinguishing agent, which is composed of the following components in percentage by weight:

[0008] Fluorine-containing surfactant 4-10%, hydrocarbon surfactant 5-20%, sea water resistant foaming agent 5-20%, foam stabilizer 3-7%, cosolvent 2-6%, anti-freezing agent 15-25%, and the rest is pure water.

[0009] Optionally, the fluorine-containing surfactant is perfluorooctyl betaine surfactant.

[0010] Optionally, the hydrocarbon surfactant is a combination of alkyl betaine amphoteric surfactant and polyoxyethylene type nonionic surfactant.

[0011] Optionally, the alkyl betaine amphoteric surfactant is dodecyl betaine, the polyoxyethylene type nonionic surfactant is fatty amine polyoxyethylene ether, and the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether is 1:1-1.5.

[0012] Optionally, the sea water resistant foaming agent is polyethylene glycol octyl phenyl ether.

[0013] Optionally, the foam stabilizer is any one or more of sodium alginate, xanthan gum, and sodium carboxymethyl cellulose.

[0014] Optionally, the cosolvent is urea.

[0015] Optionally, the anti-freezing agent is any one of 1,2-propanediol and ethylene glycol.

[0016] The application also provides a preparation method of the sea water resistant environment-friendly water film forming foam extinguishing agent.

[0017] S1: fluorine-containing surfactant and hydrocarbon surfactant are weighed according to the proportion, mixed and stirred to obtain a premix A;

[0018] S2: sea water resistant foaming agent, foam stabilizer, cosolvent and water are weighed according to the proportion, mixed and stirred to obtain a premix B;

[0019] S3: anti-freezing agent is weighed according to the proportion, premix A is first poured into a stirring tank, then premix B is added to premix A, mixed and stirred uniformly, finally the anti-freezing agent is slowly added for stirring, the pH value is adjusted to 7.0±0.5, the temperature in the stirring tank is controlled to 45℃, and the concentrated liquid of the water film forming foam extinguishing agent is prepared after stirring uniformly, standing for a period of time, and defoaming treatment.

[0020] From the above technical solutions, the application has the following advantages:

[0021] The hydrocarbon surfactant used in the application is a combination of amphoteric surfactants of alkyl betaine and non-ionic surfactants of polyoxyethylene type. Compared with using a single type of hydrocarbon surfactant, the compounded hydrocarbon surfactant can produce more abundant and stable foam, has wider applicability and better effect. Meanwhile, the addition of the hydrocarbon surfactant can reduce the use amount of fluorocarbon surfactant, thereby reducing the impact of the fire extinguishing agent on the environment and human body, and being more environmentally friendly.

[0022] The fluorine-containing surfactant used in the application is perfluorooctyl betaine surfactant. Perfluorooctyl betaine surfactant has higher surface activity and lower critical micelle concentration than hydrocarbon surfactants due to the special structure of the hydrophobic segment. Moreover, perfluorooctyl betaine surfactant has good thermal stability due to the high stability of the fluorine-containing segment. Therefore, the combination of perfluorooctyl betaine surfactant and compounded hydrocarbon surfactant in the water film forming foam extinguishing agent has better extinguishing effect. Compared with the fluorine-containing surfactant, perfluorooctane sulfonate (PFOS), used in the traditional water film forming foam extinguishing agent, perfluorooctyl betaine surfactant can reduce the toxicity of the substance by replacing the sulfonic acid group structure, increase the degradability of the water film forming foam extinguishing agent, and thus reduce the harm to the environment and human body during the use of the water film forming foam extinguishing agent.

[0023] The application provides a preparation method of the seawater-resistant and environmentally friendly water film forming foam extinguishing agent. Different raw materials are mixed in batches to prepare a concentrated solution, so that the subsequent concentrated solution can be diluted to prepare water film forming foam extinguishing agents with different dilution ratios. DETAILED DESCRIPTION

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0025] Embodiment 1

[0026] A seawater-resistant and environmentally friendly water film forming foam extinguishing agent, consisting of the following components by weight percentage:

[0027] Fluorine-containing surfactant: perfluorooctyl betaine surfactant 6%;

[0028] hydrocarbon surfactant: combination of amphoteric surfactant of alkyl betaine and non-ionic surfactant of polyoxyethylene type 15%, wherein the amphoteric surfactant of alkyl betaine is dodecyl betaine, the non-ionic surfactant of polyoxyethylene type is fatty amine polyoxyethylene ether, and the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether is 1:1.25;

[0029] sea water resistant foaming agent: polyethylene glycol octyl phenyl ether 12.5%;

[0030] foam stabilizer: sodium alginate 5%;

[0031] co-solvent: urea 4%;

[0032] antifreeze: 1,2-propanediol 20%;

[0033] the rest is pure water.

[0034] A preparation method of a sea water resistant environment-friendly water film forming foam extinguishing agent, the preparation method comprising the following steps:

[0035] S1: weighing fluorine-containing surfactant and hydrocarbon surfactant according to the proportion, mixing and stirring to obtain premix A;

[0036] S2: weighing sea water resistant foaming agent, foam stabilizer, co-solvent and water according to the proportion, mixing and stirring to obtain premix B;

[0037] S3: weighing antifreeze according to the proportion, first pouring premix A into a stirring tank, then adding premix B into premix A, mixing and stirring uniformly, finally slowly adding antifreeze for stirring, adjusting pH value to 7.0±0.5, controlling the temperature in the stirring tank to be 45℃, stirring uniformly, standing for a period of time, and preparing a concentrated solution of water film forming foam extinguishing agent after defoaming treatment.

[0038] Example 2

[0039] A sea water resistant environment-friendly water film forming foam extinguishing agent, consisting of the following components in percentage by weight:

[0040] fluorine-containing surfactant: perfluorooctyl betaine surfactant 4%;

[0041] hydrocarbon surfactant: combination of amphoteric surfactant of alkyl betaine and non-ionic surfactant of polyoxyethylene type 18%, wherein the amphoteric surfactant of alkyl betaine is dodecyl betaine, the non-ionic surfactant of polyoxyethylene type is fatty amine polyoxyethylene ether, and the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether is 1:1.5;

[0042] sea water resistant foaming agent: polyethylene glycol octyl phenyl ether 5%;

[0043] Foam stabilizer: sodium carboxymethyl cellulose 7%;

[0044] Co-solvent: urea 6%;

[0045] Anti-freezing agent: 1,2-propanediol 15%;

[0046] The rest is pure water.

[0047] A preparation method of a seawater-resistant environment-friendly water film forming foam extinguishing agent is the same as the preparation steps in Example 1.

[0048] Example 3

[0049] A seawater-resistant environment-friendly water film forming foam extinguishing agent is composed of the following components in percentage by weight:

[0050] Fluorine-containing surfactant: perfluorooctyl betaine surfactant 10%;

[0051] Hydrocarbon surfactant: combination of amphoteric surfactant of alkyl betaine and non-ionic surfactant of polyoxyethylene type 20%, wherein the amphoteric surfactant of alkyl betaine is dodecyl betaine, the non-ionic surfactant of polyoxyethylene type is fatty amine polyoxyethylene ether, and the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether is 1:1;

[0052] Seawater-resistant foaming agent: polyethylene glycol octyl phenyl ether 20%;

[0053] Foam stabilizer: sodium alginate and xanthan gum, total 3%, wherein the weight ratio of sodium alginate to xanthan gum is 1:1;

[0054] Co-solvent: urea 2%;

[0055] Anti-freezing agent: 1,2-propanediol 25%;

[0056] The rest is pure water.

[0057] A preparation method of a seawater-resistant environment-friendly water film forming foam extinguishing agent is the same as the preparation steps in Example 1.

[0058] Comparative Example 1

[0059] The difference between this comparative example and Example 1 is that the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether in the hydrocarbon surfactant is 1:2, and the weight ratio of the remaining substances and the preparation steps are the same as those in Example 1.

[0060] Comparative Example 2

[0061] The difference between the present comparative example and example 1 is that only polyoxyethylene type nonionic surfactant fatty amine polyoxyethylene ether is used as the hydrocarbon surfactant, the weight percentage of the hydrocarbon surfactant is 15%, and the weight ratio of the remaining substances and the preparation steps are the same as those of example 1.

[0062] Comparative example 3

[0063] The difference between the present comparative example and example 1 is that only amphoteric surfactant dodecyl betaine is used as the hydrocarbon surfactant, the weight percentage of the hydrocarbon surfactant is 18%, and the weight ratio of the remaining substances and the preparation steps are the same as those of example 1.

[0064] Comparative example 4

[0065] The difference between the present comparative example and example 1 is that the weight percentage of the fluorine-containing surfactant is 15%, the weight percentage of the hydrocarbon surfactant is 2%, and the weight ratio of the remaining substances and the preparation steps are the same as those of example 1.

[0066] The water film forming foam extinguishing agent prepared in examples 1-3 and comparative examples 1-4 is detected according to the national standard GB 15308-2006 "Foam extinguishing agent" to test the surface tension, diffusion coefficient, foaming multiple and 25% liquid separation time of the water film forming foam extinguishing agent, and the detection results are shown in Table 1, and the fire extinguishing time and anti-burning performance of each water film forming foam extinguishing agent are detected, and the detection results are shown in Table 2.

[0067] Table 1

[0068]

[0069] Table 2

[0070] Extinguishing time (min) Burn resistance time (min) Standard requirement ≤ 3 min ≥ 10 min Example 1 1.2 12 Example 2 1.5 15 Example 3 1.6 14 Comparative Example 1 2.5 11 Comparative Example 2 2.6 10.8 Comparative Example 3 2.6 10.5 Comparative Example 4 2.8 10

[0071] From the detection results of Table 1 and Table 2, it can be seen that the diffusion coefficients of the water film forming foam extinguishing agents prepared in examples 1-3 and comparative examples 1-4 are positive, that is, they all meet the thermodynamic conditions of spreading on the oil surface, and can realize spontaneous spreading on the oil surface.

[0072] The surface tension is also an important index for measuring whether the water film forming foam extinguishing agent can spontaneously spread on the oil surface to form a water film to inhibit the evaporation of oil gas, and the surface tension affects the flowability of the foam, the greater the surface tension, the weaker the flowability of the foam, which is easy to cause the foam to separate liquid in the process of extinguishing, and the low surface tension is more conducive to the formation of the foam, the density of the foam is smaller than that of water, so the foam can form a relatively thick foam layer on the oil surface, and has a small surface tension, which can promote the water separated from the foam extinguishing agent to form a water film on the surface of the hydrocarbon fuel with a smaller specific gravity and quickly disperse, and the extinguishing is performed through the combined shielding effect of the water film and the foam, and the surface tension values of the water film forming foam extinguishing agents of the examples 1 to 3 are lower than those of the comparative examples 1 to 4, and the effects are better;

[0073] The foaming multiple affects the foaming capacity of the foam extinguishing agent, the better the foaming capacity, the faster the foam layer is generated, and the better the extinguishing effect, the foaming multiple of the water film forming foam extinguishing agent prepared in the examples 1 to 3 meets the standard, and the foaming multiple is 8.0 or more, which is a high foaming coefficient extinguishing agent;

[0074] The 25% liquid separation time refers to the time required for 25% of the liquid in the foam to separate, and the value is too small or too large, which will affect the extinguishing effect, too small will cause the foam to quickly lose water to become dry foam to affect the flowability, and too large will indicate that the water separation is slow to cause the oil surface temperature to drop slowly. The 25% liquid separation time of the water film forming foam extinguishing agent prepared in the examples 1 to 3 is within 4 to 6 minutes, which is longer than that of the comparative examples 1 to 4, and the foam is more stable at room temperature, and can better balance the needs of foam flowability and oil surface temperature reduction in the extinguishing process.

[0075] The water film forming foam extinguishing agent prepared in the examples 1 to 3 is tested, and compared with the water film forming foam extinguishing agent prepared in the comparative examples 1 to 4, the extinguishing time is shorter, the burning resistance time is longer, and the extinguishing performance is better.

[0076] The present application can obtain a water film forming foam extinguishing agent with good extinguishing performance and environmental protection by limiting the components of the fluorine-containing surfactant, the compounded hydrocarbon surfactant, the seawater-resistant foaming agent, the foam stabilizer, the cosolvent and the antifreeze.

[0077] The above examples are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A seawater-resistant, environmentally friendly aqueous film-forming foam fire extinguishing agent, characterized in that, The aqueous film-forming foam extinguishing agent is composed of the following components by weight percentage: Fluorinated surfactant 4-10%, hydrocarbon surfactant 5-20%, seawater resistant foaming agent 5-20%, foam stabilizer 3-7%, cosolvent 2-6%, antifreeze agent 15-25%, the remainder is pure water; The foam stabilizer is sodium carboxymethyl cellulose; The antifreeze agent is 1,2-propanediol; The hydrocarbon surfactant is a combination of dodecyl betaine and fatty amine polyoxyethylene ether, wherein the weight ratio of dodecyl betaine to fatty amine polyoxyethylene ether is 1:1 to 1.

5. The seawater-resistant foaming agent is polyethylene glycol octylphenyl ether.

2. The seawater-resistant, environmentally friendly aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that, The fluorinated surfactant is perfluorooctyl betaine surfactant.

3. The seawater-resistant, environmentally friendly aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that, The co-solvent is urea.

4. The seawater-resistant, environmentally friendly aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that, The preparation method of the seawater-resistant and environmentally friendly aqueous film-forming foam fire extinguishing agent includes the following steps: S1: Weigh out the fluorinated surfactant and hydrocarbon surfactant according to the proportion, mix and stir to obtain premix A; S2: Weigh seawater resistant foaming agent, foam stabilizer, cosolvent and water according to the proportion, and stir to mix to obtain premix B; S3: Weigh the antifreeze according to the proportion. First, pour premix A into the mixing tank, then add premix B to premix A and mix and stir evenly. Finally, slowly add the antifreeze and stir, and adjust the pH value to 7.0±0.

5. Control the temperature in the mixing tank to 45°C. After stirring evenly, let it stand for a period of time. After standing and defoaming treatment, the concentrated solution of aqueous film-forming foam extinguishing agent is obtained.

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