RU2441685C2 - Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures - Google Patents

Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures Download PDF

Info

Publication number
RU2441685C2
RU2441685C2 RU2010106445/05A RU2010106445A RU2441685C2 RU 2441685 C2 RU2441685 C2 RU 2441685C2 RU 2010106445/05 A RU2010106445/05 A RU 2010106445/05A RU 2010106445 A RU2010106445 A RU 2010106445A RU 2441685 C2 RU2441685 C2 RU 2441685C2
Authority
RU
Russia
Prior art keywords
hydrogen
explosion
inhibitor
gas
ignition
Prior art date
Application number
RU2010106445/05A
Other languages
Russian (ru)
Other versions
RU2010106445A (en
Inventor
Вилен Вагаршевич Азатян (RU)
Вилен Вагаршевич Азатян
Тимур Рафкатович Тимербулатов (RU)
Тимур Рафкатович Тимербулатов
Виктор Захарович Школдыченко (RU)
Виктор Захарович Школдыченко
Original Assignee
Тимур Рафкатович Тимербулатов
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Тимур Рафкатович Тимербулатов filed Critical Тимур Рафкатович Тимербулатов
Priority to RU2010106445/05A priority Critical patent/RU2441685C2/en
Publication of RU2010106445A publication Critical patent/RU2010106445A/en
Application granted granted Critical
Publication of RU2441685C2 publication Critical patent/RU2441685C2/en

Links

Images

Abstract

FIELD: fire fighting chemicals.
SUBSTANCE: invention refers to chemical extinguishing measures including gas-forming chemically active substances and, more precisely, to substances retarding chemical reactions containing organic compounds. It can be used to protect industrial premises where hydrogen is produced as a target or by-product, also for storage and transportation of hydrogen. Gas compound preventing inflammation and explosion of hydrogen-air mixture includes hydrocarbon deterrent containing 2-8 atoms of carbon diluted by phlegmatizing carbon dioxide. Gas compound is two-component. As a deterrent, it contains i-C4H8 isobutene - at least 5.0% of protected volume given optimal ratio of components, vol. %: isobutene/carbon dioxide - 1:2.4. The invention ensures guarantee prevention of inflammation of hydrogen-air in the protected volume in all ratios of all its components.
EFFECT: retardation of chemical reactions containing organic compounds thus allowing extinguishing fire.
1 dwg, 1 dwg

Description

The invention relates to chemical fire extinguishing agents, including gas-generating chemically active substances, and more specifically, to compositions that slow down chemical reactions containing organic compounds, and can be used to protect industrial premises where hydrogen is formed as a target or by-product during storage and transportation hydrogen.

The prior art characterizes a gas inhibitor for preventing ignition and explosion of hydrogen-air mixtures described in patent 2081892, C09K 15/04, 1997, which is a normal, cyclic or isostructure hydrocarbon containing from one to eight carbon atoms or their mixtures.

The inhibitor concentration for reliable protection of the hydrogen-air mixture is optimized in the content range from 0.1 to 15.5 vol.%.

The use of this inhibitor reduces the upper concentration limit of ignition when the hydrogen content in the mixture is from 75 to 29.5 vol.% And greatly reduces the lower concentration limit of flame propagation.

However, the described inhibitor itself is flammable and can convert the non-combustible mixture to combustible, which limits its practical use.

More perfect is a universal gas composition to prevent ignition and explosion of combustible mixtures (hydrogen and methane-air), containing a hydrocarbon inhibitor diluted with phlegmatizer, which is described in patent 2169597, A62D 1/00, A62C 3/06, 2001.

The inhibitor is selected from a number of hydrocarbons containing from two to eight carbon atoms in the molecule, and is a mixture, vol.%: 17 propylene, 41 butane and 42 propane (AKAM trademark).

As a phlegmatizer, a fluorine-containing freon, mainly perfluorobutane, was used.

The optimal volume ratio in the composition of the inhibitor and chladone is defined as 15-42% and 58-85%, respectively, which ensures the prevention of ignition and explosion of hydrogen and methane-air mixtures while reducing the consumption of the inhibitor of increased efficiency of the main action.

The disadvantage of the described composition is that perfluorobutane is toxic and, upon combustion, forms fluorophosgene, a chemical warfare agent, which impedes its practical use for its intended purpose.

In addition, this expensive inhibitor has a very high density (10 times higher than air), so the mixture is prone to delamination and significantly increases the consumer cost of work, thereby limiting practical use.

The noted drawback is eliminated in the gas composition in the invention according to the patent 2187351 C2, A62D 1/08, 2002, which is selected as the closest analogue by the number of matching features.

The hydrocarbon inhibitor of known gas composition is made in the form of a mixture of saturated and unsaturated hydrocarbons propane, butane and propylene grade AKAM.

The diluent is an inert gas from the series nitrogen, carbon dioxide, argon, and mixtures thereof.

The ratio of hydrocarbon inhibitor and inert gas (carbon dioxide) in the known composition is defined as 5-10 vol.% And 90-95 vol.%, Respectively, provided that the prepared composition is introduced into the combustible mixture in an amount of 5-43 vol.%.

The known inhibitory gas composition is characterized by high safety and efficiency, especially in the region of the lower concentration limit of the flame propagation of hydrogen and methane, which allows it to be used to prevent an explosion in mines both with slow and fast methane supply, as well as in the production and use of hydrogen and methane.

A continuation of the advantages of this universal composition is its inherent disadvantages, in particular, the restriction on use due to the high content in the atmosphere of the inhabited room (42-45 vol.%, See table 1 and p.5 of the description), necessary for reliable prevention of ignition and explosion hydrogen-air mixture, since ballast carbon dioxide dramatically limits human activity.

At the lower limit of the carbon dioxide content in the known gas mixture, its use to inhibit hydrogen-air mixtures is fundamentally impossible, since ignition will occur and an explosion will inevitably occur.

The technical problem to which the present invention is directed is to improve the known gas mixture in order to guarantee the prevention of ignition and explosion of the hydrogen-air mixture over the entire range of components.

The stated technical problem is solved in that the known gas composition for preventing ignition and explosion of a hydrogen-air mixture, comprising a hydrocarbon inhibitor containing 2-8 carbon atoms, diluted with phlegmatizing carbon dioxide, according to the invention, is made two-component and contains isobutene chemical formula iC 4 H as an inhibitor 8 not less than 5.0% of the protected volume, with an optimal ratio of components, vol.%: Isobutene / carbon dioxide as 1: 2.4.

Distinctive features provided guaranteed prevention of ignition of the protected volume with the hydrogen-air mixture in the entire range of the ratio of its components.

Replacing a three-component inhibitor, compared with the closest analogue, with one - isobutene (an unsaturated hydrocarbon with a tertiary carbon atom) significantly (several times) increases the efficiency of the effect on ignition, combustion and explosion of hydrogen-air mixtures.

This is due to the fact that the double bond, which actively traps hydrogen atoms, is located at the tertiary carbon atom in the structure of the isobutene molecule, which greatly facilitates the termination of reaction chains.

The implementation of the two-component inhibitory gas composition simplifies the preparation technology, increases the effectiveness of the main action due to the use of a much more active inhibitor than the AKAM mixture with the inhibitory compositions of analogues.

The minimum content of the proposed inhibitor in a two-component gas composition is optimized to guarantee the prevention of ignition of the hydrogen-air mixture in the protected room both during slow leakage of hydrogen and its avalanche-like breakthrough into the atmosphere of volume.

The content of 70 vol.% In the carbon dioxide inhibiting composition provides phlegmatization of the hydrogen-air mixture, reducing the concentration range of both ignition thresholds, which isobutene in the amount of 5.0 vol.% Of the protected room acts selectively, completely inhibiting its gas filling.

The percentage of oxygen in the atmosphere of the protected premises is reduced by 2.5 vol.%, Which does not significantly affect human activity.

When the content of carbon dioxide in the protected volume of the room is less than 12 vol.% (Below 70 vol.% Of the inhibitory composition), the ignition of the hydrogen-air filling mixture in its most explosive hydrogen content in the region of 7.5 vol.% Is not prevented. Combustion proceeds sluggishly, without explosion.

The content in the inhibitory composition of carbon dioxide of more than 13 vol.% Is ballast and impractical, since there is no increase in the effectiveness of its intended purpose.

Therefore, each essential feature is necessary, and their combination in a stable relationship is sufficient to achieve a novelty of quality that is not inherent in the characteristics of disunity, that is, the technical problem posed in the invention is not solved by the sum of the effects, but by a new super-effect of the sum of the attributes.

A comparative analysis of the identified analogues of the prior art, from which the proposed technical solution does not explicitly follow for a specialist in fire fighting equipment, showed that it is not known, but taking into account the possibility of industrial use of a two-component gas composition for protection against ignition of storage volumes of hydrogen-air mixtures or rooms, into the atmosphere of which hydrogen is likely to enter, it can be concluded that the patentability criteria are met.

Carbon dioxide serves as a phlegmatizing component of the functional mixture, but, having a high heat capacity, takes away reactive heat, which helps to inhibit the combustion of hydrogen-air mixtures by increasing the efficiency of the hydrocarbon inhibitor itself under the conditions of the developed chain nature of the ignition and explosion process.

The proposed gas mixture is characterized not by the additive inhibitory effect of the structural components, but significantly larger: by the exponential function of acad. N. N. Semenova, which determines the dependence of the rate of the combustion reaction during the joint use of the gases of the inhibitory mixture (see, for example, the journal “Kinetics and Catalysis”, t. 48, No. 1, p. 12, Avetisyan A.A., Azatyan V. B. and others).

A multiple increase in the effectiveness of the inhibitory effect of a mixture of two gases is explained by the following feature. If the inhibitory effect of two gases is determined by x and y, then when used in a mixture, the action is not determined by the sum (x + y), but by the exponential function exp (x + y) or the same exponential function e (x + y) , which quantitatively fundamentally inadequate to the sum of the inhibitory ability of the components, but by orders of magnitude more.

It is obvious that the observed strong suppression of the ignition and explosion of hydrogen-air mixtures with a relatively small amount of inhibitory composition cannot be caused either by dilution of the combustible mixture or by an increase in its heat capacity.

It is also impossible to explain the suppression of combustion by the additional consumption of oxygen in its parallel, independent reaction with the inhibitor.

In addition, at certain concentrations of the inhibitor, ignition does not occur at all (there is no oxygen consumption), but the hydrogen-air mixtures are protected.

Indeed, the amount of isobutene, at which a strong inhibition of combustion is manifested, is significantly less than the lower concentration limits of the flame propagation of hydrogen-air mixtures under the influence of this inhibitor.

Since the narrowing of the indicated concentration region means the prevention of ignition, that is, the reaction of oxygen, the inhibitory effect of the inhibitor has nothing to do with its consumption.

The branched chain mechanism leads to ignition regardless of the self-heating of the system, but during the development of the chain mechanism, the heat generated enhances it, further accelerating the process. Therefore, by preventing a chain avalanche, the inhibitor eliminates self-heating.

The suppression of hydrogen combustion by a hydrocarbon inhibitor, isobutene, is caused by the termination of reaction chains by a quick reaction:

H + C 4 H 8 = H 2 + C 4 H 7 .

Replacing a chemically active H atom with a C 4 H 7 radical is equivalent to breaking the reaction chain, since this radical is not capable of regenerating the active particle by its reactions.

Thus, the inhibitory effect of isobutene in the presence of carbon dioxide, in an optimized quantitative ratio, on the ignition of hydrogen-air mixtures increases many times, which helps to prevent ignition and explosion.

Isobutene is a strong inhibitor that effectively interrupts reaction chains, dynamically intercepting active particles, thereby preventing their avalanche-like reproduction.

Thus, chemical control of the combustion process is carried out by means of small additives of special substances.

Ignition and combustion is the process of formation and propagation of active intermediate particles: atoms and fragments of molecules that repeatedly rapidly interact with the starting reagents. The expenditure of the starting reagents becomes avalanche, that is, chain ignition occurs.

The chain mechanism of any gas-phase combustion is realized due to the positive feedback of the concentration of active particles and their volume of change over time.

The bursting combustion process is accompanied by self-heating, which further enhances the chain avalanche.

The proposed inhibitor in an optimized ratio of constituent components prevents a chain avalanche of burning a hydrogen-air mixture of any concentration and, consequently, an explosion.

The introduction of the proposed gas inhibitory composition into the hydrogen-air mixture leads to a significant decrease in the ratio of branching rate and chain termination, as a result of which the process as a whole is inhibited.

The inhibitor (isobutene) is consumed in reactions with active intermediate products of hydrogen combustion, it reacts mainly with hydrogen atoms, the concentration of which is much higher than the concentration of oxygen atoms and OH radicals.

Carbon dioxide in the proposed inhibitory composition is a phlegmatizer that enhances the action of the inhibitor by reducing the concentration of the oxidizing agent, and also acts as a more active third particle of the trimolecular reaction, which stabilizes the product of recombination:

H + O 2 + M = H 2 O + M.

Thus, the proposed composition allows you to actively control the combustion process due to its insignificant addition directly to the atmosphere of the protected volume, preventing the ignition and explosion of hydrogen-air mixtures in the entire range of component concentrations, which is clearly confirmed by the attached graph in the drawing, which shows the experimentally obtained dependence of ignition and explosion of hydrogen-air mixtures of various concentrations from changes in the proportion of inhibitory isobutene in a gas composition containing di ksid carbon.

The drawing shows:

1 - combustion zone of a hydrogen-air mixture with an inhibitor (In) by analogy;

2 - combustion zone of a hydrogen-air mixture with an inhibitor according to the invention;

3 - explosion zone of the hydrogen-air mixture.

It follows from the graph that when the proposed inhibitory composition contains at least 5.0 vol.% Isobutene and 12 vol.% Carbon dioxide in the protected volume, ignition and explosion of hydrogen-air mixtures of any concentration are completely excluded.

The action of the proposed inhibitory composition was studied in cylindrical reactors of various sizes, withstanding pressures up to 100 atm, which are equipped with a photodiode for detecting chemiluminescence ignition and a pressure sensor, as well as in a test bench reactor with a volume of 4 m 3 .

Working gas mixtures containing air, hydrogen and a two-component inhibitory gas composition according to the invention were prepared directly in the reactor. The reactor was pre-evacuated to a pressure of 0.4 Pa, and then the inhibitory composition, hydrogen and air were successively injected in predetermined volumes, controlling their amount by partial pressures.

The prepared gas inhibited mixture was ignited using a spark source, a hot wire, and also an open flame of the burner flame. No ignition was observed.

Ignition of a gas mixture without an inhibitor was recorded visually and using a photodiode by flame emission (chemiluminescence), as well as by pressure jump and reagent consumption.

The inhibitory composition of the invention is non-combustible, stored under normal conditions without delamination for a long time.

The high safety of the proposed inhibitory gas composition and the effectiveness of the intended action, especially in the region of the lower concentration limit of the distribution of the hydrogen flame, ensure its use in the production and transportation of hydrogen.

Claims (1)

  1. A gas composition for preventing ignition and explosion of a hydrogen-air mixture comprising a hydrocarbon inhibitor containing 2-8 carbon atoms, diluted with phlegmatizing carbon dioxide, characterized in that it is made of two components and contains, as an inhibitor, the chemical formula iC 4 H 8 of at least 5.0 % of the protected volume at the optimum ratio of components, vol.%: isobutene / carbon dioxide as 1: 2.4.
RU2010106445/05A 2010-02-26 2010-02-26 Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures RU2441685C2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
RU2010106445/05A RU2441685C2 (en) 2010-02-26 2010-02-26 Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
RU2010106445/05A RU2441685C2 (en) 2010-02-26 2010-02-26 Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures

Publications (2)

Publication Number Publication Date
RU2010106445A RU2010106445A (en) 2011-09-10
RU2441685C2 true RU2441685C2 (en) 2012-02-10

Family

ID=44757179

Family Applications (1)

Application Number Title Priority Date Filing Date
RU2010106445/05A RU2441685C2 (en) 2010-02-26 2010-02-26 Gas compound used to prevent inflammation and explosion of hydrogen-air mixtures

Country Status (1)

Country Link
RU (1) RU2441685C2 (en)

Also Published As

Publication number Publication date
RU2010106445A (en) 2011-09-10

Similar Documents

Publication Publication Date Title
Liu et al. The chemical effect of CO2 replacement of N2 in air on the burning velocity of CH4 and H2 premixed flames
RU2554581C2 (en) Fire-extinguishing composition forming fire-extinguishing agent at high temperature decomposition
JP6166387B2 (en) Improved adsorbent formulation for the removal of mercury from exhaust gas
Hastie Molecular basis of flame inhibition
CN102179027B (en) Ferrocene extinguishing composition
Camino et al. Performance and mechanisms of fire retardants in polymers—a review
Oxley et al. Ammonium nitrate: thermal stability and explosivity modifiers
Chiu et al. The dynamic flammability and toxicity of magnesium hydroxide filled intumescent fire retardant polypropylene
US6024889A (en) Chemically active fire suppression composition
Beyler Flammability limits of premixed and diffusion flames
Buszek et al. Water effects on atmospheric reactions
US5425886A (en) On demand, non-halon, fire extinguishing systems
JP3766685B2 (en) Fire extinguishing method and system
TWI280887B (en) Fire extinguishing mixtures, methods and systems
USRE40651E1 (en) Labile bromine fire suppressants
RU2414273C2 (en) Extinguishant, method for making thereof and method of fire extinguishing
Linteris et al. Experimental and numerical evaluation of metallic compounds for suppressing cup-burner flames
RU2481138C2 (en) Fire-extinguishing aerosol composition for precise electric appliances
JP2015220263A (en) Pressure reduction processing apparatus and exhaust gas explosion-proof method
Babushok et al. Combustion properties of halogenated fire suppressants
Sheinson et al. The physical and chemical action of fire suppressants
Kondo et al. Extended Le Chatelier's formula for carbon dioxide dilution effect on flammability limits
US9878190B2 (en) Flame retardant and fire extinguishing product for fires in solid materials
WO2000048683A1 (en) Fire suppression composition and device
Di Benedetto et al. Reconsidering the flammability diagram for CH4/O2/N2 and CH4/O2/CO2 mixtures in light of combustion-induced Rapid Phase Transition

Legal Events

Date Code Title Description
PC41 Official registration of the transfer of exclusive right

Effective date: 20130717

MM4A The patent is invalid due to non-payment of fees

Effective date: 20160227