Aqueous film-forming foam fire extinguishing agent and preparation method thereof

Abstract

The invention discloses an aqueous film-forming foam fire extinguishing agent. The fire extinguishing agent comprises the following components by mass percentage: 0.5%-1.5% of a fluorocarbon surfactant, 2.5%-8.0% of a hydrocarbon surfactant, 5.0%-16.0% of a foaming agent, 2.0%-7.0% of a solubility promoter, 3.0%-13.5% of an anti-burning agent, 2.0%-7.0% of an antifreeze agent, 10.5%-32.5% of a thickener, 0.1%-1% of a preservative, and the balance is water, and the sum of the above components is 100%. A preparation method of the aqueous film-forming foam fire extinguishing agent is also provided. The preparation method is simple, easy to operate, and has low cost. The prepared fire extinguishing agent is environmentally friendly and has high fire extinguishing effect.

Description

Technical Field

[0001] The invention relates to a fire extinguishing agent and a preparation method thereof, in particular to an aqueous film-forming foam fire extinguishing agent and a preparation method thereof, and belongs to the field of fire extinguishing materials. Background Art

[0002] When HFC-227ea fire extinguishing agent first appeared, it was widely used and researched because of its characteristics of being colorless, odorless, having strong insulation properties, and not easily causing secondary pollution during the fire extinguishing process.

[0003] However, traditional hydrofluorocarbon fire extinguishing agents such as HFC-227ea have a significant greenhouse effect. In 2016, at the 28th Conference of the Parties to the Montreal Protocol held in Kigali, the capital of Rwanda, nearly 200 countries were included in the restricted list by consensus through the amendment.

[0004] Compared with HFC-227ea fire extinguishing agent, aqueous film-forming foam fire extinguishing agent has a fire extinguishing effect that is not inferior to HFC-227ea fire extinguishing agent due to its dual fire extinguishing effects of water film and foam. Moreover, more than 97% of the components of aqueous film-forming foam fire extinguishing agent are water, and there will be no greenhouse effect.

[0005] Most of the aqueous film-forming foam fire extinguishing agents on the market currently use perfluorooctane sulfonyl compounds (PFOS) as fluorocarbon surfactants, but PFOS has extremely poor degradation performance and is an organic pollutant that is difficult to decompose. And because of its high toxicity, bioaccumulation and other disadvantages, it has been included in the Stockholm Convention since 2009, that is, it is banned from production and use internationally. In March 2019, my country also issued a joint document by 11 national ministries and commissions including the Ministry of Ecology and Environment to gradually ban PFOS / PFOA, and complete the complete ban by the end of 2023. At the same time, the current popular fluorocarbon surfactants that do not contain PFOS / PFOA in the world are C6 fluorocarbon surfactants (PFHxS), which are not completely non-toxic. In October 2017, it was included in the list of substances of high concern by the European Union; and it has been gradually banned by international organizations in recent years. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an aqueous film-forming foam fire extinguishing agent and a preparation method thereof. The preparation method is simple, easy to operate and low in cost. The prepared fire extinguishing agent is environmentally friendly and has a high fire extinguishing effect.

[0007] In order to solve the above technical problems, the present invention provides an aqueous film-forming foam fire extinguishing agent, which comprises the following components by mass percentage:

[0008] Fluorocarbon surfactant: 0.5%-1.5%,

[0009] Hydrocarbon surfactant: 2.5%-8.0%,

[0010] Foaming agent: 5.0%-16.0%,

[0011] Cosolvent: 2.0%-7.0%,

[0012] Anti-burning agent: 3.0%-13.5%,

[0013] Antifreeze: 2.0%-7.0%,

[0014] Thickener: 10.5%-32.5%,

[0015] Preservatives: 0.1%-1%,

[0016] The balance is water, and the sum of the above components is 100%.

[0017] The technical solution further defined in the present invention is:

[0018] Furthermore, in the aforementioned aqueous film-forming foam fire extinguishing agent, the fluorocarbon surfactant is a perfluorinated branched short-chain fluorocarbon anionic surfactant having 5 straight-chain fluorocarbon atoms.

[0019] In the aforementioned aqueous film-forming foam fire extinguishing agent, the fluorocarbon surfactant is a sulfonate anionic fluorocarbon surfactant, and its structure is as follows:

[0020]

[0021] In the aforementioned aqueous film-forming foam fire extinguishing agent, the hydrocarbon surfactant is dodecyltrimethylammonium bromide.

[0022] In the aforementioned aqueous film-forming foam fire extinguishing agent, the co-solvent is diethylene glycol monobutyl ether.

[0023] Technical effect: the auxiliary solvent of the present invention uses diethylene glycol monobutyl ether, which not only plays a dissolving effect, but also can enhance the stability of the foam.

[0024] In the aforementioned aqueous film-forming foam fire extinguishing agent, the anti-burning agent is urea.

[0025] Technical effect: The present invention uses urea, which not only has an anti-burning effect, but also can further increase the stability of the foam and has a certain solubility-promoting effect.

[0026] In the aforementioned aqueous film-forming foam fire extinguishing agent, the antifreeze agent is ethylene glycol.

[0027] In the aforementioned aqueous film-forming foam fire extinguishing agent, the thickener is alkyl polyglycoside APG0810.

[0028] Technical effect: Alkyl polyglycoside as a foam stabilizer has good foam stability and can also improve the foaming ability of the system.

[0029] In the aforementioned aqueous film-forming foam fire extinguishing agent, the foaming agent is dodecyl betaine.

[0030] Technical effect: the present invention uses dodecyl betaine to make the fire extinguishing agent achieve good foaming effect.

[0031] In the aforementioned aqueous film-forming foam fire extinguishing agent, the preservative is one or both of sodium benzoate and potassium sorbate.

[0032] Technical effect: one or both of the preservatives sodium benzoate and potassium sorbate are used as food additives, which have good bactericidal and preservative effects and are pollution-free.

[0033] In the aforementioned aqueous film-forming foam fire extinguishing agent, the water is preferably deionized water or industrial soft water.

[0034] The present invention also provides a method for preparing an aqueous film-forming foam fire extinguishing agent, which specifically comprises the following steps:

[0035] Weigh the fluorocarbon surfactant and the hydrocarbon surfactant according to the proportion of the components, mix and stir to form component A;

[0036] Weigh a thickener, a cosolvent, a foaming agent, a preservative and water and mix them to form component B;

[0037] Finally, weigh the anti-burning agent and the anti-freezing agent and mix them evenly to form component C;

[0038] Add B to A and mix, then slowly add C and stir evenly to make a concentrated solution of aqueous film-forming foam fire extinguishing agent.

[0039] The beneficial effects of the present invention are:

[0040] The present invention specifically selects diethylene glycol monobutyl ether and urea when selecting the co-solvent, the anti-burning agent and the foam stabilizer, which not only have the original effects but also increase the stability of the foam;

[0041] From the perspective of high efficiency and environmental protection, the present invention compounded the sulfonate anionic fluorocarbon surfactant and the hydrocarbon surfactant, and found that the anionic fluorocarbon surfactant and the hydrocarbon surfactant produced an excellent synergistic effect when compounded: the critical micelle concentration (CMC) of the fluorocarbon surfactant in the present invention is 5×10 -3 mol / L, the corresponding surface tension is 21.84mN / m, and after adding dodecyltrimethylammonium bromide, the CMC can be reduced to 1.953×10 -5mol / L, the corresponding surface tension drops to below 20mN / m. In the aqueous film-forming foam fire extinguishing agent, the spreading speed determines the fire extinguishing speed of the product to a certain extent, and the spreading speed is closely related to the surface tension of the solution; in addition, the concentration of fluorocarbon surfactants is generally higher than their CMC value. Therefore, this method achieves rapid fire extinguishing through a compounding method while taking into account economic benefits.

[0042] The sulfonate anionic fluorocarbon surfactant used in the present invention can reduce the surface tension of water to below 22mN / m, which is better than hydrocarbon surfactants. In addition, the fluorocarbon surfactant has little pollution to the environment and is a green and environmentally friendly surfactant. It also has high thermal stability and chemical stability. The mechanism of action is to reduce the surface tension of water, so that the foam solution can form a water film on the oil surface and spread quickly, sealing the oil surface, thereby achieving rapid fire extinguishing.

[0043] The invention has a long storage time, and the addition of anti-burning agent, anti-freezing agent and preservative makes the invention more capable of resisting changes in external conditions and not easy to deteriorate. The main components of the fire extinguishing agent and the added additives are non-toxic and pollution-free, and it is a green and environmentally friendly product.

[0044] The preparation method of the present invention does not involve a chemical reaction process, and each component has good solubility. Therefore, the whole process does not require heating, filtering, and no three wastes are generated. It only needs to be mixed in an aqueous solution, which is environmentally friendly and energy-saving, easy to operate, and has high production efficiency.

[0045] The present invention can ensure low surface tension and good spreading performance through the compounding of fluorocarbon surfactant and hydrocarbon surfactant, seal the oil surface, thereby achieving rapid fire extinguishing, improving fire extinguishing efficiency, and the foam fire extinguishing efficiency made by the present invention is high and stable. Among them, the added anti-burning agent urea plays an anti-burning role while further increasing the stability of the foam, and has a certain solubilizing effect, and the solubilizing agent diethylene glycol monobutyl ether not only plays a solubilizing effect, but also can strengthen the stability of the foam, and the alkyl polyglycoside has good foam stability as a foam stabilizer, and can also improve the foaming ability of the system. These components can improve the foam stability, so that the present invention can reduce the surface tension of the foam solution to form a more stable water film on the oil surface during fire extinguishing, and the fire extinguishing performance is more stable, belonging to a high-efficiency and environmentally friendly product, and can be widely used in oil fields, oil depots, ships, submarines, petrochemical production, hangars, airports and other multi-field fire prevention key units. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is the sulfonate anionic fluorocarbon surfactant in the embodiment of the present invention. 1 HNMR spectra;

[0047] Figure 2is the sulfonate anionic fluorocarbon surfactant in the embodiment of the present invention. 19 FNMR images;

[0048] Figure 3 This is a fire extinguishing diagram of the aqueous film-forming foam fire extinguishing agent in Example 1 of the present invention;

[0049] Figure 4 This is the anti-burning diagram of the aqueous film-forming foam fire extinguishing agent in Example 1 of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The fluorocarbon surfactant of the present invention is a sulfonate anion fluorocarbon surfactant, and its structure is as follows:

[0052]

[0053] Sulfonate anionic fluorocarbon surfactant 1 HNMR images Figure 1 As shown, 19 FNMR images Figure 2 shown.

[0054] The hydrocarbon surfactant used in the present invention is dodecyltrimethylammonium bromide, which has excellent foaming performance and can reduce the interfacial tension between the foam solution and the oil surface. The following is the surface tension and critical micelle concentration of the final fire extinguishing agent after compounding the sulfonate anionic fluorocarbon surfactant and different hydrocarbon surfactants at a compounding ratio of 1:1. The data are shown in Table 1 below:

[0055] Table 1 Surface tension and critical micelle concentration data of sulfonate anionic fluorocarbon surfactants and different hydrocarbon surfactant systems

[0056]

[0057] As can be seen from Table 1, the hydrocarbon surfactant selected in the present invention is dodecyl trimethyl ammonium bromide, which can significantly reduce the surface tension of the aqueous solution of the fluorocarbon surfactant to 20.25 mN / m, with the lowest surface tension, so that the foam solution can form a water film on the oil surface and spread quickly to seal the oil surface, thereby achieving rapid fire extinguishing and effectively improving the fire extinguishing efficiency.

[0058] The sulfonate anionic fluorocarbon surfactant in the fire extinguishing agent components prepared in the following examples and comparative examples is available in the prior art, and the other raw materials are also commercially available products.

[0059] Example 1

[0060] The aqueous film-forming foam fire extinguishing agent provided in this embodiment is prepared as follows:

[0061] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant and 5.36 kg of dodecyltrimethylammonium bromide respectively, mix them evenly to form mixture A; weigh 21.8 kg of alkyl glycoside, 4.38 kg of diethylene glycol monobutyl ether, 10.45 kg of dodecyl betaine, 0.5 kg of sodium benzoate, and 20 kg of water, mix them evenly to form mixture B, add B to A and stir; weigh 6.52 kg of urea and 4.38 kg of ethylene glycol, mix them evenly to form mixture C, slowly add them to A, and finally dilute with water to 100 kg, stir evenly to obtain 100 kg of foam fire extinguishing agent concentrate.

[0062] Example 2

[0063] The aqueous film-forming foam fire extinguishing agent provided in this embodiment is prepared as follows:

[0064] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant and 5.36 kg of dodecyltrimethylammonium bromide respectively, mix them evenly to form mixture A; weigh 21.8 kg of alkyl glycoside, 4.38 kg of diethylene glycol monobutyl ether, 5.22 kg of dodecyl betaine, 0.5 kg of sodium benzoate, and 20 kg of water, mix them evenly to form mixture B, add B to A and stir; weigh 6.52 kg of urea and 4.38 kg of ethylene glycol, mix them evenly to form mixture C, slowly add them to A, and finally dilute with water to 100 kg, stir evenly to obtain 100 kg of foam fire extinguishing agent concentrate.

[0065] Example 3

[0066] The aqueous film-forming foam fire extinguishing agent provided in this embodiment is prepared as follows:

[0067] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant and 5.36 kg of dodecyltrimethylammonium bromide respectively, mix them evenly to form mixture A; weigh 21.8 kg of alkyl glycoside, 4.38 kg of diethylene glycol monobutyl ether, 10.45 kg of dodecyl betaine, 0.5 kg of sodium benzoate, and 20 kg of water, mix them evenly to form mixture B, and add B to A with stirring; weigh 13.04 kg of urea (does it still exceed the component ratio) 3%-10%, and 4.38 kg of ethylene glycol, mix them evenly to form mixture C, slowly add them to A, and finally dilute with water to 100 kg, stir evenly to obtain 100 kg of foam fire extinguishing agent concentrate.

[0068] Example 4

[0069] The aqueous film-forming foam fire extinguishing agent provided in this embodiment is prepared as follows:

[0070] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant and 5.36 kg of dodecyltrimethylammonium bromide respectively, mix them evenly to form mixture A; weigh 13 kg of alkyl glycoside, 4.38 kg of diethylene glycol monobutyl ether, 10.45 kg of dodecyl betaine, 0.5 kg of sodium benzoate, and 20 kg of water, mix them evenly to form mixture B, add B to A and stir; weigh 6.52 kg of urea and 4.38 kg of ethylene glycol, mix them evenly to form mixture C, slowly add them to A, and finally dilute with water to 100 kg, stir evenly to obtain 100 kg of foam fire extinguishing agent concentrate.

[0071] Comparative Example 1

[0072] This comparative example provides an aqueous film-forming foam fire extinguishing agent, which is prepared as follows:

[0073] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant as mixture A; weigh 21.8 kg of alkyl glycoside, 4.38 kg of diethylene glycol monobutyl ether, 0.5 kg of sodium benzoate, and 20 kg of water, mix well to form mixture B, add B to A and stir; weigh 6.52 kg of urea and 4.38 kg of ethylene glycol, mix well to form mixture C, slowly add to A, and finally dilute with water to 100 kg, stir well to obtain 100 kg of foam fire extinguishing agent concentrate.

[0074] Comparative Example 2

[0075] This comparative example provides an aqueous film-forming foam fire extinguishing agent, which is prepared as follows:

[0076] Weigh 0.89 kg of sulfonate anionic fluorocarbon surfactant, 5.36 kg of hexadecyltrimethylammonium bromide, and 10.45 kg of dodecyl betaine respectively, and mix them evenly to form mixture A; weigh 21.8 kg of alkyl glycoside and mix them evenly, and add 4.38 kg of diethylene glycol monobutyl ether, 0.5 kg of sodium benzoate, and 20 kg of water to form mixture B, and add B to A and stir; weigh 6.52 kg of urea and 4.38 kg of ethylene glycol to form mixture C, and slowly add them to A. Finally, dilute with water to 100 kg and stir evenly to obtain 100 kg of foam fire extinguishing agent concentrate.

[0077] The solution prepared by mixing the concentrated liquid product of Comparative Example 1 with water in a volume ratio of 3:97 was tested with reference to the national inspection standard "GB15308-2006": its expansion coefficient was negative. It can be seen that if the sulfonate anionic fluorocarbon surfactant is used alone, the surface tension of the aqueous solution is insufficient to enable the foam solution to form a water film on the oil surface and spread quickly, so the oil surface cannot be sealed, the water film cannot spread on the oil surface, and it does not have the fire extinguishing effect.

[0078] The specific components of the aqueous film-forming foam fire extinguishing agent concentrate prepared in Examples 1-4 and Comparative Example 2 and the fire extinguishing agent concentrate prepared in Comparative Example 1 are shown in Table 2 below.

[0079] Table 2 Data on the content of each component of the fire extinguishing agent in Examples 1-4 and Comparative Examples 1-2

[0080]

[0081] The physicochemical properties and fire extinguishing performance of the solution prepared by mixing the fire extinguishing agent concentrate obtained in the above Examples 1-4 and Comparative Example 2 with water in a volume ratio of 3:97 all meet the requirements of GB15308-2006. The product self-inspection is carried out according to the national standard "GB15308-2006", and the various technical indicators are shown in Table 3 below, among which the fire extinguishing effect and anti-burning effect of the fire extinguishing agent in Example 1 are as follows: Figure 3 and Figure 4 shown.

[0082] Table 3 Physical and chemical properties and fire extinguishing performance parameters of the solution prepared by mixing the fire extinguishing agent concentrate obtained in Examples 1-4 and Comparative Example 2 with water in a volume ratio of 3:97

[0083]

[0084] From the data in Table 3, it can be seen that adding hydrocarbon surfactants to the aqueous film-forming foam fire extinguishing agent can effectively achieve the fire extinguishing effect. The foaming multiple, 25% liquid separation time, fire extinguishing time and anti-burning time of each embodiment all meet the relevant requirements. At the same time, by comparing Example 1 and Comparative Example 2, it is found that the type of hydrocarbon surfactant also affects the fire extinguishing effect of the product. Example 1 has the best fire extinguishing effect, and the fire extinguishing time is as low as 0.53min, which is much lower than the fire extinguishing time of the existing aqueous film-forming foam fire extinguishing agent on the market.

[0085] Figure 3 0-60s is the pre-combustion stage of n-heptane, and a stable combustion state is reached at 60s. Subsequently, foam is injected. At 70s, due to the large amount of heat released by the combustion of n-heptane, the foam injected into the oil pool quickly de-foams, and the flame is still strong. Continue to inject foam, so that a large amount of foam accumulates on the surface of n-heptane, further reducing the flame temperature and the combustion area, until the flame is completely extinguished at 92s. It can be seen that the fire extinguishing effect is good and the time is fast.

[0086] Figure 4 Shows the foam's anti-burning performance test process, from Figure 4 It can be seen that the foam backburning process can be divided into three stages: the foam expansion stage, the foam layer decay stage and the flame reburning stage. 0-226s is the foam expansion stage, which is due to the ignition of n-heptane in the burning pot, causing the gas inside the foam to expand and the volume to increase. 226-372s is the decay stage of the foam layer. As the heat released by the combustion of n-heptane increases, the upper layer of foam cannot accept it and decomposes. 522-621s is the reburning stage. At this time, pores begin to appear on the surface of the foam, and a small amount of n-heptane begins to overflow from the bottom. Due to the continuous reduction of the foam layer, the combustion area gradually expands, eventually leading to the combustion of the entire oil pool. It can be seen that the fire extinguishing effect is good and the burning resistance is good.

[0087] From the above implementation results, it can be seen that the present invention has the following characteristics:

[0088] (1) The preparation method of this product does not involve a chemical reaction process, but only requires mixing in an aqueous solution, and each component has good solubility. Therefore, the whole process does not require heating or filtering, and no three wastes are generated. It is environmentally friendly and energy-saving, easy to operate, and has high production efficiency.

[0089] (2) The product of the present invention produces synergistic effects by compounding with hydrocarbon surfactants and greatly reduces the usage of fluorocarbon surfactants. While reducing the cost of aqueous film-forming foam fire extinguishing agents, it improves the fire extinguishing efficiency of the product, taking into account economic benefits while being green and environmentally friendly.

[0090] (3) The hydrocarbon surfactants used have little toxicity to the environment and are green and environmentally friendly substances; the fluorocarbon surfactants are new perfluorinated branched short-chain fluorocarbon anionic surfactants, which are non-toxic and have excellent biodegradability and cause little pollution to the environment; diethylene glycol monobutyl ether, ethylene glycol, dodecyl betaine and sodium benzoate are organic compounds widely used in various chemical industries and cause little pollution to the environment; urea is one of the most common organic fertilizers, and its environmental harm as an anti-burning agent of the present invention is negligible; therefore, the product of the present invention is an environmentally friendly product.

[0091] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. An aqueous film-forming foam fire extinguishing agent, characterized in that: The fire extinguishing agent includes the following components by mass percentage: Fluorocarbon surfactant: 0.5%-1.5%, Hydrocarbon surfactant: 2.5%-8.0%, Foaming agent: 5.0%-16.0%, Solvent: 2.0%-7.0%, Anti-burning agent: 3.0%-13.5%, Antifreeze: 2.0%-7.0%, Thickener: 10.5%-32.5%, Preservatives: 0.1%-1%, The balance is water, and the sum of the above components is 100%; The fluorocarbon surfactant is a sulfonate anionic fluorocarbon surfactant, and its structure is as follows: ； The hydrocarbon surfactant is dodecyltrimethylammonium bromide.

2. The aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The cosolvent is diethylene glycol monobutyl ether.

3. The aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The anti-burning agent is urea; the anti-freezing agent is ethylene glycol.

4. The aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The thickener is alkyl polyglycoside APG0810.

5. The aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The foaming agent is lauryl betaine.

6. The aqueous film-forming foam fire extinguishing agent according to claim 1, characterized in that: The preservative is one or both of sodium benzoate and potassium sorbate.

7. A method for preparing the aqueous film-forming foam fire extinguishing agent according to any one of claims 1 to 6, characterized in that: The specific steps include: Weigh the fluorocarbon surfactant and the hydrocarbon surfactant according to the proportion of the components, mix and stir to form component A; Weigh a thickener, a cosolvent, a foaming agent, a preservative and water to form component B; Finally, weigh the anti-burning agent and the anti-freezing agent and mix them evenly to form component C; Add B into A and mix, then slowly add C and stir evenly to make a concentrated solution of aqueous film-forming foam fire extinguishing agent.

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