What is "carbon monoxide". Its properties and formula
Carbon monoxide poisoning, unfortunately, is not such a rare accident that accompanies the illiterate operation of solid fuel or gas boiler, fireplace, gas stove, water heater. Spread of a toxic substance can also occur if broken equipment is used. A frightening prospect, you will agree.
Miniature device - sensor carbon monoxide for the house will promptly warn the owners, exclude Negative consequences. It reliably detects the appearance in the air harmful substances. Here you will learn how to choose it correctly, where to install it, how to monitor and respond to the device’s readings.
In the article we presented, the principle of operation is thoroughly analyzed and the types of sensors that ensure the safety of household members are given. The installation process is carefully described, valuable recommendations. To optimize perception, the material is supplemented with visual illustrations and video tips.
Carbon monoxide, or CO as it is also called, is a product of the oxidation reaction of substances at high temperatures, simply put, carbon monoxide is formed during the combustion process. CO is always released in small quantities when food is cooked.
However, excess permissible norm The presence of gas in a room is fraught with serious damage to health, and can sometimes lead to death.
Carbon monoxide kills thousands of people every year simply because people fail to perceive the threat before symptoms occur. This often happens when it is too late to do anything.
Only special devices can detect the substance in the air, because the gas has neither odor nor color. In addition, it has a toxic effect on the body upon inhalation.
When carbon monoxide enters the lungs, it combines with hemoglobin to form carboxyhemoglobin. The substance interferes with the process of saturating blood cells with oxygen and causes hypoxia of body tissues.
To determine the presence of gas in the air, sensors are used, the scope of which is demonstrated by a photo selection:
Image gallery
As a result, work is disrupted internal organs, the nervous system and brain are primarily affected.
The severity of poisoning depends on the amount of carbon monoxide in the room:
- With a CO content of 0.08%, the first symptoms of poisoning are mild malaise and drowsiness.
- Then it begins headache and dizziness, cough appears.
- In especially severe cases, damage to the mucous membranes of the nasopharynx, paleness of the skin and disruption of the heart are observed.
- When the level increases to 0.32%, loss of consciousness, coma and paralysis occur due to oxygen starvation, and death occurs within half an hour.
- If the gas level rises to 1.2%, the person dies within 3 minutes.
Leakage of the substance occurs mainly in private buildings due to faulty ventilation and. Besides gas appliances, boilers and other equipment often break down, and as a result, CO levels rise in the room.
An example is the most common case when poisoning occurs during sleep, because intoxication cannot be identified by smell.
Gas used in everyday life and its combustion products cannot be detected without a device, because they have no color or smell
For rescue, the victim must be immediately taken out into fresh air. It is also recommended to perform deep ventilation of the lungs using an oxygen mask.
Often the cause of a leak is poor draft over an open fire source, illiterate arranged system smoke removal or malfunction of the gas stove. When living in the private sector, you need to follow safety precautions when using heating elements.
When igniting solid fuel boilers and stoves, do not close the damper ahead of time. In addition, the layout of some private houses also includes an attached garage, which can lead to excessive release of fumes and its entry into the living part of the premises. This is especially dangerous if the extension is poorly ventilated.
Emergency protection equipment
To eliminate false fears about a possible leak, it is worth installing a carbon monoxide identification system. The device will report on the state of air in the room and notify residents if toxic fumes exceed the norm.
The detector does a good job of detecting not only CO, but will also alert residents to a leak. domestic gas. If a fire has already started, the sensor will not recognize it, but in terms of preventative measure- he is irreplaceable.
The detector can be located on any vertical surface. The display constantly reports the status of the device and the level of toxic gases in the air
The device will instantly respond to changes chemical composition air. According to installation rules, it is best not to install sensors in close proximity to open fire sources, but simply in the same room with heating equipment.
If the room is equipped with several heating units, it is necessary to organize a system of equal amount detectors.
A wide range of manufacturers provide consumers with different carbon monoxide detection devices every year. Despite the fact that the form factor of each device is determined individually, the design principle is almost always the same.
The operating principle and specifics of the sensor device are introduced in the photo:
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A distinctive feature of the gas detection device is that the detector is not designed to identify smoke. This means that in addition to the CO sensor, it is recommended to install a fire safety system separately.
The sensor's response to exceeding permissible parameters in the air is a sound signal, which indicates a toxic gas leak. Before use, you must read the instructions and test the device in an accessible, non-hazardous way, because People often confuse a CO leak signal with an audible low battery indicator.
There are portable devices that have already become an integral attribute of carbon safety in many countries, including Russia
Also, almost all devices have a function. The tone and interval of each sound is different. If the detector signals a low battery, the sound in most cases has a clear, abrupt character and occurs once per minute.
A constant squeak from the detector may indicate an increase in the level of toxins in the air, or a breakdown of the equipment. In any case, you must immediately call emergency services.
If symptoms of poisoning are detected, you must immediately open all windows and, after leaving the room, wait for the team outside.
Technicians will check oxygen levels and identify leaks. If it turns out that the signal is false, the detector will need to be replaced with a new one.
Some carbon and natural monoxide detectors for the home are able to recognize even fairly safe substances that have a high degree of evaporation. This primarily applies to alcohol and all alcohol-containing liquids.
When using alcohol-based cleaning products, you need to better ventilate the room to avoid false alarms of the security system.
If there is a high concentration of vapors, the system may sound an alarm, but do not worry and immediately call the emergency service. Also, the detector may be triggered during the preparation of certain products, mainly those that have undergone the fermentation process.
This is mainly typical when the device is located close to hob. If this happens quite often, you should install the sensor away from the cooking area.
Types of air analyzers and their advantages
Increasingly, people are resorting to using certain models of household CO sensors. The most popular options include 3 main types of devices:
- Semiconductor based detectors.
- Infrared sensors.
- Devices with electrochemical detection method.
In order to understand which device will flawlessly cope with the task of detecting dangerous gas and is suitable for the means and installation methods, you need to understand their specifics.
#1: Semiconductor gas detectors
Equipment of the first type is fundamentally different from the other two, because works on the principle of chemical processes of interaction between atoms of substances. In most cases, dioxides are used as the active substance, namely carbon, tin and ruthenium.
Semiconductor alarms are connected directly to the power supply network. Basically, you will hardly find similar battery-powered equipment on the market.
The method for determining toxins is to increase the conductivity of the affected air. As a result, contact between the detector components occurs. Then a mechanism is activated, signaling the presence of carbon monoxide. The reaction occurs between atoms.
SnO 2 (tin dioxide), or RuO 2 (ruthenium dioxide). To carry out the diffusion of atoms, it is necessary that chemical elements were exposed to heating at a temperature of at least 250 degrees Celsius.
The conductivity of clean air in a device based on SnO 2 and RuO 2 is extremely low, so the device is active only in the presence of CO.
When heated, electrons begin to be released from oxygen atoms under the influence of carbon monoxide. This process increases the conductivity of the detector capsule, which causes the sensor contacts to close, and as a result, an alarm is triggered.
Voltage primarily depends on the amount of CO monoxide in the air. When the permissible level is exceeded, the voltage increases, so there are practically no false positives recorded with the semiconductor detector.
The only exceptions are when the device is located too close to the fireplace hearth, stove firebox, etc. This is true for all types of equipment. Therefore, it is recommended to install at some distance from the heating panels.
The design of a semiconductor sensor begins with a solid base. It is made from polymer material, related to saturated polyesters. The body itself is made of stainless steel. The front part plays the role of an inlet where air contaminated with toxins penetrates.
To prevent the penetration of combustion-related substances, the detector body contains a carbon layer. The latter performs the function of an absorbent. It also provides protection against physical contaminants such as dust. double layer stainless mesh.
The sensitive element is located deep in the housing, under a layer of carbon filter. The voltage is connected directly to the metal terminals on the other side of the capsule
In most cases, semiconductor sensors have 3 contacts for connecting electricity. This is due to the fact that the design of the device contains 2 electrical circuits - for the heater and for the metal dioxide element.
Sensor of this type is different high degree wear resistance and long service life. In addition, due to its small dimensions, it consumes extremely little electricity, but in terms of CO detection, the device is on the list of the most efficient.
The video presents the device of a semiconductor detector, an example of the sensor’s performance:
#2: Infrared variety of analyzers
A completely different operating principle is observed with infrared sensors. Here, air acts as an analyzer, which is then tested for the presence of CO using infrared irradiation.
The main criterion that determines the level of carbon monoxide is the wave spectrum of the IR element, which absorbs carbon monoxide toxin molecules. Due to the fact that light is much more sensitive to external influence, these types of sensors successfully identify a variety of pollutants, including methane.
The IR sensor is programmed to a certain CO level, which is considered a reference value. If the set limit is exceeded, an alarm is triggered.
The role of the sensitive element is performed by an LED or an incandescent filament. Such IR gas leak sensors are called non-dispersive. The gas level is analyzed thanks to special light filters that are configured to perceive only a specific spectrum.
Sensors of this type are not often used in our country. Due to the increased price, they are installed mainly in large institutions
If the chemical composition of the air changes, the element reacts, the light wave changes, and the detector detects an excess of the permissible level of the desired gas. In this case, the level of spectrum change is directly proportional to the percentage of the chemical in the air.
Detectors of this type are often used not only in everyday life, but also as special devices for detecting toxic leaks. The selectivity of the equipment allows it to successfully scan the air for the presence of heavy gases such as ammonia and chlorine.
As for the design, the device is powered by connecting to a 220 V network. However, most options for household devices include the ability to operate on batteries.
To indicate gas contamination, the device is equipped with a backlit display and an audible alarm system. If a gas leak is detected, the sensor will immediately produce a clear, abrupt squeak, and the device monitor will begin to blink.
#3: Catalytic Gas Detectors
The main difference between electrochemical sensors is the rather low level of energy consumption. This is due primarily to the fact that the design of the device does not include heating element, and the role of a sensitive substance is performed by a liquid electrolyte.
Therefore, the equipment can easily do without connecting to the network, but run on rechargeable batteries. The structure of the sensor is such that the air condition is analyzed by determining the level of oxidation of the substance inside the capsule of the device. As a rule, the electrical environment chemical reactions is a galvanic cell filled with a liquid alkaline solution (mainly potassium).
As practice shows, alkali has some disadvantages, including low resistance to carbon monoxide and a short shelf life.
However, some manufacturers prefer to create an electrolytic environment using a mixture of acidic solutions. Such a cell is much more resistant to the effects of third-party molecules and, as a result, more durable.
Gas molecules (in this case CO) come into contact with the electrode of the device, resulting in a chemical oxidation reaction. The electrolyte records the level of voltage that occurs and converts this indicator into the level of gas content. The higher the percentage of waste, the stronger the electrolysis.
The alarm control process is carried out by a small microcircuit in which the specific level of the presence of waste is registered. Therefore, according to the already familiar principle, if the norm is exceeded, the sensor signals danger.
A microcomputer inside the case monitors voltage changes with high accuracy due to increased chemical reactions to CO
To maintain the purity of the active medium, along with semiconductor sensors, a carbon filter, which traps unwanted molecules mixed with carbon monoxide. Thus, the effectiveness of the device is supported by a chemical system. protection, which reduces the likelihood of false activation.
Some models allow you to replace spoiled electrolyte and refill the galvanic capsule.
The advantages of catalytic sensors and the principle of their operation are demonstrated in the video:
Features of gas sensors
The form factor of some devices requires the presence of a so-called electromagnetic relay, through which the sensor can be connected to the gas pipeline valve plug system.
The main purpose of the system is that such a sensor, when an alarm is triggered, instantly shuts off the gas supply in the pipe, thereby ensuring complete safety.
The relay can be connected as a separate element to control the damper. Some devices already have this system.
Modern equipment also provides a number of functions for notifying the occurrence of an emergency using conventional mobile phone. In most cases, systems of this kind are typical for imported devices and among domestic analogues meeting them is quite problematic.
However, some manufacturers have taken care of the possibility of connecting additional GSM peripherals to notify the owner of the house via SMS.
The mobile signal transmitter looks like a regular microcircuit. Connection is made according to the instructions included with the CO detector.
Alarm installation process
Most detectors come with a special fastener, on which the device will subsequently land. It is recommended to mount it on a wall closer to the ceiling.
It should be noted that in European countries, mounting a carbon monoxide detector on a wall near a fireplace is considered gross violation. Installation there is allowed only on the ceiling, unlike the CIS, where the sensor is often installed at a distance of at least 1.5 m from the floor.
Since the sensors detect not only carbon monoxide, but also natural gas, you need to understand some installation considerations. When installing a gas alarm system, the device should be mounted at different heights.
If the house is connected to a pipeline with natural gas, the sensor should be placed closer to the ceiling. In the case of bottled gas - closer to the floor. This is explained by the different densities of gaseous combustible substances.
Natural is lighter than the liquefied balloon version. When there is a leak, it rises upward, while the balloon one, on the contrary, first fills the lower levels of the room.
The choice of location and height for installing the gas presence sensor in the air depends on the type of gaseous fuel. To detect natural gas leaks, the device is mounted at the top; to detect a propane-butane mixture, it is placed at the bottom of the room (+)
When organizing a gas leak prevention system, you should not rely 100% on the functions of the sensor. The device performs only a monitoring task and will not be able to protect people’s lives in the event of an emergency.
Before installing in the required order, you should check. If it is working properly, install it.
To check the draft yourself, you can bring a lit lighter or candle to the ventilation hatch. You can also use a piece of paper
The process of connecting the sensor to the power supply must be carried out exclusively by a competent specialist, otherwise problems may occur if the power supply is incorrect. You should not neglect this rule, and it is better to contact a professional, because... Someone's life depends on the success of the enterprise.
When choosing a location for the module, make sure that at least one of the sensors is located in the bedroom. This is important to consider. After all, most accidents involving carbon monoxide leaks occur while sleeping.
If the house consists of several floors, it is necessary to provide a fire protection system for each floor of the room through which the components pass.
When installing the sensor in the same room as the fire source, you should follow minimum distance between the source and the sensor. As a rule, for an objective analysis of air, you need to maintain a distance of 4-5 m.
Some sensor models are triggered when the air temperature rises above 50 degrees. This phenomenon occurs when a fire starts in the room and the source of the flame is in close proximity to the device. At the same time, the amount of fume released may not yet reach an alarming level.
The device must be located in such a place that nothing interferes with the air flow. This is typical for cases where the detector mount is located behind a curtain. Air circulation around the sensor is main point, which you need to pay attention to. Because some interior objects may block the inlet of the device and as a result the system will not provide 100% protection.
You can check the functionality of the analyzer different ways. The easiest way is to buy a special CO2 canister. By spraying it near the detector, you can make sure that the installation operation is correct.
A can of carbon dioxide can be found at any hardware store. You need to be careful when using it, because... the substance is under pressure
It is worth observing some points when implementing this process. Firstly, under no circumstances should you direct the aerosol stream directly at the device. This is important because the direct concentration of the substance is tens of times higher than the actual amount required to trigger the sensor.
Such an undertaking can either negatively affect the functionality of the sensor or simply disable it. Most manufacturers insist on specialized equipment inspection by qualified technicians. Naturally, the procedure is paid, but this way you can be sure that the CO detector is working properly.
To avoid breakdowns, you need to keep the room clean, first of all, try to prevent dust from accumulating on the sensor body.
Conclusions and useful video on the topic
Major safety violations during installation gas equipment and recommendations on how to avoid carbon monoxide poisoning:
Carbon monoxide is dangerous because at high concentrations it can kill in a matter of minutes. Detectors will take care of home safety by organizing round-the-clock monitoring of air composition. The choice of device depends only on personal preferences and the price of the device.
Please write comments: share your experience in choosing and using gas analyzers, ask questions. We and site visitors are ready to participate in the conversation and clarify unclear points.
Carbon monoxide (CO) or carbon monoxide is a colorless, odorless gas that is lighter than air. The so-called "carbon monoxide smell" is caused by impurities organic matter in fuel. Carbon monoxide is produced every time it is burned. wood fuel. The main reason for the formation of carbon monoxide: lack of oxygen in the combustion zone. "Burning" and "fuming" are common names for carbon monoxide poisoning.Carbon monoxide formation in the furnace
Carbon monoxide is formed when carbon burns in a lack of oxygen. Fuel combustion in furnaces occurs in several stages: carbon burns with the release of carbon dioxide CO 2 (incomplete combustion flue gases); then carbon dioxide interacts with hot coke residues of fuel or coal, forming carbon monoxide; carbon monoxide burns (blue flames) to form carbon dioxide, which is removed through the chimney.
If there is no draft in the stove (the chimney is clogged, the damper is closed prematurely, there is no supply air for combustion), coals continue to smolder in conditions of insufficient oxygen supply, carbon monoxide does not burn and can spread throughout the heated room, causing a toxic effect on the human body and poisoning (fumes).
Carbon monoxide CO and carbon dioxide CO 2
The processes of formation of carbon dioxide into carbon monoxide and vice versa, during the combustion of fuel in a furnace, occur continuously. When the fuel is almost burned out, the combustion of carbon monoxide with a blue flame and the formation of carbon dioxide ( component flue gases). Under normal combustion conditions, all carbon monoxide burns in the firebox of the stove with virtually no residue.
Carbon dioxide CO 2 is a colorless gas with a faint sour odor. Carbon dioxide, being heavier than air, accumulates in depressions (basements, wells, adits, catacombs, caves). When a room becomes smoky with reverse draft in the chimney, there is just a lot of carbon dioxide.
Carbon monoxide CO is a product of incomplete combustion and a strong poison. Carbon dioxide poisoning has less toxic effects.
Causes of carbon monoxide poisoning
The lack of color and odor of poisonous carbon monoxide makes carbon monoxide especially dangerous. The cause of carbon monoxide poisoning is:
- Violation of operating rules stove heating(untimely closing of the furnace damper, insufficient access fresh air into the firebox, poor traction).
- Malfunction of the stove and chimney (cracks in the stove structure, clogged chimney).
- Finding a person at the source of a fire.
- Car maintenance in a garage or area with poor ventilation.
- Sleeping in a car with the engine running.
- Use of poor quality air in scuba gear and breathing apparatus
- Using a charcoal grill in a barbecue gazebo with poor ventilation.
The symptoms of poisoning are very difficult to recognize at first, so you may not realize that carbon monoxide is the cause of your illness. The manifestation of the same symptoms in all people in the same room makes it possible to recognize the moment of carbon monoxide poisoning.
With a small concentration of carbon monoxide, the first signs of toxicity and poisoning may appear: lacrimation, headache and dizziness, weakness and nausea, dry cough, confusion, possible visual and auditory hallucinations. If you feel the symptoms of poisoning, leave the room as quickly as possible, going out into the fresh air. In an open space, the risk of poisoning is minimal.
If you spend a long time in a room with a small concentration of carbon monoxide, symptoms of poisoning are observed: respiratory failure, tachycardia, loss of coordination of movements, visual hallucinations, drowsiness, blue discoloration of the mucous membranes and facial skin, vomiting, possible convulsions, loss of consciousness.
With an increased concentration of carbon monoxide in the indoor air, loss of consciousness and coma with convulsions occur. Without providing first aid to a victim of carbon monoxide poisoning, death may occur.
Effect of carbon monoxide on the body
Carbon monoxide enters through the lungs, binds to hemoglobin in the victim’s blood and blocks the transfer of oxygen to tissues and organs. Oxygen starvation disrupts the functioning of the nervous system and brain. The higher the concentration of carbon monoxide and more time being indoors, the stronger the poisoning and the higher the likelihood of death.
After poisoning, medical observation is necessary for several days, as complications are often observed. Patients with severe poisoning are subject to hospitalization. Lung problems and nervous system possible even several weeks after carbon monoxide poisoning. It’s interesting but true: carbon monoxide affects women less than men.
First aid for poisoning
We must remember that when removing a victim from a room with a dangerous concentration of carbon monoxide, first of all it is necessary to protect yourself, in order to avoid poisoning as well. The main “antidote” for carbon monoxide poisoning is oxygen. First aid for carbon monoxide poisoning:
- Remove the victim to fresh air.
- Eliminate the flow of carbon monoxide. Ventilate the room (open windows and doors) and leave the room.
- If the victim is conscious, provide continuous access to fresh air and short-term inhalation ammonia, rub the body. Call an ambulance.
- If the victim is unconscious, it is necessary to immediately begin artificial respiration until he regains consciousness or until the ambulance arrives.
- Notify the emergency physician if you suspect carbon monoxide poisoning.
Carbon monoxide detector or alarm
It is easier to avoid poisoning or inhalation by using an autonomous alarm or carbon monoxide detector in your home. If the concentration of carbon monoxide in a residential building or technical room exceeds the permissible level, the sensor signals, warning of danger. Carbon monoxide detectors are electrochemical sensors designed to continuously monitor the level of CO content in indoor air and respond with sound and light signals to an increased level of carbon monoxide concentration.
When choosing an alarm sensor, you should pay attention to the features of the devices (if they are similar in appearance): smoke alarms and open fire sensors, carbon monoxide CO sensors and carbon dioxide CO 2 sensors react to different components in the room air. Carbon monoxide sensors are mounted at a height of 1.5 meters from the floor (some manufacturing companies recommend 15-20 cm from the ceiling), a smoke sensor should hang on the ceiling, a CO 2 carbon dioxide detection device is recommended for installation at floor level or at instrument panel level ( carbon dioxide is heavier than air).
In many countries, the use of the above sensors is regulated by law to ensure public health and safety. In Europe, only a smoke detector is required. The installation of a carbon monoxide detector in homes with stove heating or a fireplace is currently voluntary. Carbon monoxide detectors are relatively inexpensive, although the price can be measured in money human life incorrect.
Preventing carbon monoxide poisoning
By following safety rules, you can avoid carbon monoxide poisoning:
- Do not use fuel burning devices without sufficient knowledge, skills and tools.
- Make sure the stove, chimney, supply and exhaust ventilation are working properly.
- Don't burn charcoal in a room with poor ventilation.
- On smoke ducts For stoves operating on wood, it is necessary to install two tight valves in series, and on the channels of stoves using coal or peat - one valve with a hole in it with a diameter of 15 mm. (clause 3.72 of SNiP 2.04.05-91*)
- Do not leave your car in the garage with the engine running.
Carbon monoxide during stove heating operation
A stove or fireplace with a closed damper and unburned fuel is a source of carbon monoxide and an invisible poisoner. Believing that the fuel has completely burned out, the stove owners close the chimney damper to conserve heat. Smoldering coals with a lack of air form carbon monoxide, which penetrates into the room through leaky areas of the stove structure.
With weak draft in the chimney and without air supply, chemical under-combustion of the fuel occurs, and as a result, the formation and accumulation of carbon monoxide. The air flow should be sufficient to both maintain the combustion process and provide optimal draft in the design of the stove or fireplace. Sealed rooms and lack of supply air are problems natural ventilation and the reasons for poor draft in the fireplace.
For good combustion fuel should be supplied to the stove firebox required amount supply air, especially when burning coal. If there are several unburned firebrands left in the firebox of a fireplace or stove, it is better to extinguish them or allow time to burn out completely. When the coals darken and there are no flames above them, after about ten minutes the valve can be closed. You should stop using the fireplace or heating the stove 2 hours before bedtime.
If a stove or fireplace is properly operated and maintained, the amount of carbon monoxide produced during fuel combustion is usually not dangerous. Caution is the key to preventing carbon monoxide poisoning.
Copyright © 2009 CAMMEO
- UN hazard class 2.3
- Secondary hazard according to UN classification 2.1
Molecule structure
The CO molecule, like the isoelectronic nitrogen molecule, has a triple bond. Since these molecules are similar in structure, their properties are also similar - very low melting and boiling points, close values of standard entropies, etc.
Within the framework of the valence bond method, the structure of the CO molecule can be described by the formula: C≡O:, and the third bond is formed according to the donor-acceptor mechanism, where carbon is the acceptor of the electron pair, and oxygen is the donor.
Due to the presence of a triple bond, the CO molecule is very strong (dissociation energy 1069 kJ/mol, or 256 kcal/mol, which is greater than that of any other diatomic molecules) and has a small internuclear distance (d C≡O = 0.1128 nm or 1. 13Å).
The molecule is weakly polarized, the electric moment of its dipole μ = 0.04·10 -29 C m (direction of the dipole moment O - →C +). Ionization potential 14.0 V, force coupling constant k = 18.6.
History of discovery
Carbon monoxide was first produced by French chemist Jacques de Lassonne by heating zinc oxide with coal, but was initially mistaken for hydrogen because it burned with a blue flame. The fact that this gas contains carbon and oxygen was discovered by the English chemist William Cruickshank. Carbon monoxide outside the Earth's atmosphere was first discovered by the Belgian scientist M. Migeotte in 1949 by the presence of a main vibrational-rotational band in the IR spectrum of the Sun.
Carbon monoxide in the Earth's atmosphere
There are natural and anthropogenic sources of entry into the Earth's atmosphere. IN natural conditions, on the Earth's surface, CO is formed by incomplete anaerobic decomposition organic compounds and during the combustion of biomass, mainly during forest and steppe fires. Carbon monoxide is formed in soil both biologically (released by living organisms) and non-biologically. The release of carbon monoxide due to phenolic compounds common in soils, containing OCH 3 or OH groups in ortho- or para-positions relative to the first hydroxyl group, has been experimentally proven.
The overall balance of non-biological CO production and its oxidation by microorganisms depends on specific environmental conditions, primarily humidity and . For example, carbon monoxide is released directly into the atmosphere from arid soils, thus creating local maximums in the concentration of this gas.
In the atmosphere, CO is the product of chains of reactions involving methane and other hydrocarbons (primarily isoprene).
The main anthropogenic source of CO is currently engine exhaust gases internal combustion. Carbon monoxide is formed when hydrocarbon fuels are burned in internal combustion engines at insufficient temperatures or the air supply system is poorly tuned (insufficient oxygen is supplied to oxidize CO into CO 2). In the past, a significant portion of the anthropogenic input of CO into the atmosphere was provided by illuminating gas, which was used for indoor lighting in the 19th century. Its composition was approximately the same as that of water gas, that is, it contained up to 45% carbon monoxide. Currently, in the public sector, this gas is replaced by much less toxic natural gas (lower representatives of the homologous series of alkanes - propane, etc.)
CO input from natural and anthropogenic sources is approximately the same.
Carbon monoxide in the atmosphere is in rapid circulation: its average residence time is about 0.1 year, being oxidized by hydroxyl to carbon dioxide.
Receipt
Industrial method
2C + O 2 → 2CO (thermal effect of this reaction is 22 kJ),
2. or when reducing carbon dioxide with hot coal:
CO 2 + C ↔ 2CO (ΔH=172 kJ, ΔS=176 J/K).
This reaction often occurs in a stove fire when the stove damper is closed too early (before the coals have completely burned out). The carbon monoxide formed in this case, due to its toxicity, causes physiological disorders (“fumes”) and even death (see below), hence one of the trivial names - “carbon monoxide”. A picture of the reactions occurring in the furnace is shown in the diagram.
The reduction reaction of carbon dioxide is reversible; the effect of temperature on the equilibrium state of this reaction is shown in the graph. The flow of a reaction to the right is ensured by the entropy factor, and to the left by the enthalpy factor. At temperatures below 400°C the equilibrium is almost completely shifted to the left, and at temperatures above 1000°C to the right (towards the formation of CO). At low temperatures the rate of this reaction is very low, so carbon monoxide is quite stable under normal conditions. This equilibrium has a special name Boudoir balance.
3. Mixtures of carbon monoxide with other substances are obtained by passing air, water vapor, etc. through a layer of hot coke, coal or brown coal, etc. (see generator gas, water gas, mixed gas, synthesis gas).
Laboratory method
TLV (maximum threshold concentration, USA): 25 MAC r.z. according to Hygienic standards GN 2.2.5.1313-03 is 20 mg/m³
Carbon Monoxide Protection
Thanks to such a good calorific value, CO is a component of various technical gas mixtures (see, for example, generator gas), used, among other things, for heating.
halogens. Greatest practical use got a reaction with chlorine:
CO + Cl 2 → COCl 2
The reaction is exothermic, its thermal effect is 113 kJ, in the presence of a catalyst (activated carbon) it occurs already at room temperature. As a result of the reaction, phosgene is formed, a substance that is widely used in various branches of chemistry (and also as a chemical warfare agent). By similar reactions, COF 2 (carbonyl fluoride) and COBr 2 (carbonyl bromide) can be obtained. Carbonyl iodide was not obtained. The exothermicity of reactions quickly decreases from F to I (for reactions with F 2 the thermal effect is 481 kJ, with Br 2 - 4 kJ). It is also possible to obtain mixed derivatives, for example COFCl (for more details, see halogen derivatives of carbonic acid).
By reacting CO with F 2 , in addition to carbonyl fluoride, one can obtain a peroxide compound (FCO) 2 O 2 . Its characteristics: melting point −42°C, boiling point +16°C, has a characteristic odor (similar to the smell of ozone), when heated above 200°C it decomposes explosively (reaction products CO 2, O 2 and COF 2), in acidic medium reacts with potassium iodide according to the equation:
(FCO) 2 O 2 + 2KI → 2KF + I 2 + 2CO 2
Carbon monoxide reacts with chalcogens. With sulfur it forms carbon sulfide COS, the reaction occurs when heated, according to the equation:
CO + S → COS ΔG° 298 = −229 kJ, ΔS° 298 = −134 J/K
Similar selenoxide COSe and telluroxide COTe were also obtained.
Restores SO 2:
SO 2 + 2CO → 2CO 2 + S
With transition metals it forms very volatile, flammable and toxic compounds - carbonyls, such as Cr(CO) 6, Ni(CO) 4, Mn 2 CO 10, Co 2 (CO) 9, etc.
As stated above, carbon monoxide is slightly soluble in water, but does not react with it. It also does not react with solutions of alkalis and acids. However, it reacts with alkali melts:
CO + KOH → HCOOK
The reaction of carbon monoxide with potassium metal in an ammonia solution is interesting. This produces the explosive compound potassium dioxodicarbonate:
2K + 2CO → K + O - -C 2 -O - K +
By reacting with ammonia at high temperatures, one can obtain an important compound for industry - hydrogen cyanide HCN. The reaction occurs in the presence of a catalyst (oxide
Carbon monoxide (CO) is a colorless, very light gas (lighter than air) and odorless. But the “smell of carbon monoxide” is felt due to impurities of organic elements in the fuel. Carbon monoxide appears every time you burn wood in your home. The main cause of carbon monoxide is an insufficient amount of oxygen in the combustion area.
The occurrence of waste
Carbon monoxide in the home occurs when carbon is burned due to a lack of oxygen. Combustion of fuel in furnaces occurs in several stages:
- First, the carbon burns, releasing carbon dioxide CO2;
- The carbon dioxide then comes into contact with the hot remains of coke or coal, creating carbon monoxide;
- The carbon monoxide then burns (blue flame) to produce carbon dioxide, which escapes through the chimney.
Without draft in the stove (the chimney is clogged, there is no supply air for combustion, the damper is closed prematurely), the coals continue to smolder without a weak supply of oxygen, so carbon monoxide does not burn and can disperse throughout the heated room, causing a toxic effect on the body and poisoning (carbon monoxide).
Factors of carbon dioxide poisoning
Carbon monoxide is odorless and colorless, making it very dangerous. The causes of smoke inhalation poisoning can be:
- Malfunctioning fireplace stove and chimney (clogged chimney, cracks in the stove).
- Violation (closing of the stove damper untimely, poor draft, insufficient access to the firebox of fresh air).
- The presence of a person at the source of the fire.
- Car maintenance in a low-ventilated area.
- The use of low-quality air in breathing apparatus and scuba gear.
- Sleeping in a car with the engine running.
- Using a grill with low ventilation.
Signals and signs of poisoning
At a low concentration of gas, the first signs of toxic effects and poisoning may form: lacrimation, dizziness and pain, nausea and weakness, confusion, dry cough, and there may be auditory and visual hallucinations. If you feel the symptoms of poisoning, you need to get out into fresh air as soon as possible.
If you spend a long period of time in a room with a low density of carbon monoxide, symptoms of poisoning occur: tachycardia, difficulty breathing, loss of coordination, drowsiness, visual hallucinations, blue discoloration of the facial skin and mucous membranes, vomiting, loss of consciousness, and there may be convulsions.
With increased concentrations, loss of consciousness and coma with convulsions occur. Without first aid, the victim may die from smoke inhalation.
The effects of carbon monoxide in the home on the human body
Carbon monoxide enters through the lungs, contacts hemoglobin in the blood and prevents the transfer of oxygen to organs and tissues. Oxygen starvation disrupts the nervous system and brain function. The higher the carbon monoxide concentration and the longer the period spent in the room, the stronger the poisoning and the greater the likelihood of death.
After poisoning, medical supervision is required for several days, as complications are often observed. Victims from severe poisoning need to be hospitalized. Problems with the nervous system and lungs are possible even weeks after the incident. Interestingly, carbon monoxide affects women less than men.
Carbon monoxide detector for home
Poisoning or carbon inhalation can be prevented by using a self-contained carbon monoxide alarm or sensor. If the volume of carbon monoxide in a residential or technical room exceeds the permissible level, the sensor will signal, warning of the threat. Carbon monoxide detectors are electrochemical sensors designed to continuously monitor the level of CO content in a room and respond with light and sound signals to high level concentrations of carbon monoxide in the air.
When you decide to buy a carbon monoxide alarm for your home, pay attention to the features (if they are similar in appearance) of the devices: open fire sensor and smoke alarm, sensor carbon monoxide and carbon dioxide reacts to different elements in the air of the room. Carbon monoxide detectors for the home are installed at a height of one and a half meters from the floor (some recommend installing 15–20 cm from the ceiling). The carbon dioxide detector should be placed near the instrument panel or at floor level (carbon dioxide is much heavier than air), and the smoke detector should be on the ceiling.
In many countries, the use of the above sensors is a mandatory condition required by law to ensure the safety and health of the population. In Europe, only a smoke detector is required. For us, installing a carbon monoxide detector is currently voluntary. Such sensors are generally an inexpensive device, so it is better not to risk your life and buy a carbon monoxide alarm for your home.
How to avoid carbon monoxide poisoning in the house
By following safety rules, smoke inhalation poisoning can be prevented:
— Do not use fuel-burning appliances without sufficient skills, knowledge and tools.
— Do not burn charcoal in a room with poor ventilation.
— Make sure the stove, exhaust and supply ventilation and chimney are working properly.
— On smoke ducts wood stoves, it is necessary to provide for the installation of 2 tight valves in series, and on the channels of stoves operating on coal or peat, only one valve with a 15 mm hole.
— Do not leave a car in the garage with the engine running.
Sensors that signal an increase in carbon monoxide concentration can additionally protect against poisoning, but they should not replace other preventive work.
Carbon monoxide from stove heating
A fireplace or stove with a closed valve and the remains of unburned fuel is a source of carbon monoxide and an invisible poisoner. Assuming that the fuel has completely burned, stove owners close the chimney damper to preserve heat. Smoldering embers with a lack of air create carbon monoxide, which penetrates into the room through leaky areas of the furnace system.
Also in the chimney, with weak draft and without air supply, chemical underburning of the fuel occurs, and as a result, the appearance and accumulation of carbon monoxide at home.
Today I want to tell you about carbon monoxide danger, often leading to the death of people. Unlike the “usual” signs of a fire, when a person sees smoke or open fire, carbon monoxide is almost impossible to notice (therefore, most often people do not burn alive in a fire, but die after inhaling smoke and carbon monoxide, even at the initial stage of the fire). And if carbon monoxide is formed or enters the room at night when you are sleeping, the probability of never waking up is very high.
Causes of carbon monoxide in the room
Carbon monoxide enters atmospheric air for any type of combustion. In cities, carbon monoxide is mainly found in the exhaust gases from internal combustion engines; it is also formed during the combustion of household gas (during insufficient quantities oxygen in the air), furnace furnaces and fires.
Carbon monoxide poisoning is possible:
- in case of fires;
- in garages poor ventilation, in other unventilated or poorly ventilated rooms, tunnels, since the exhaust of a car contains up to 1-3% CO according to standards and over 10% if the carburetor engine is poorly adjusted;
- when spending a long time on a busy road or next to it in calm weather. Attention! On large highways, the average concentration of CO exceeds the poisoning threshold (therefore, you should not drive on such roads with the car window open);
- at home when burning domestic gas in conditions of lack of oxygen and poor ventilation;
- when the stove dampers are untimely closed in rooms with stove heating (at home).
Carbon monoxide actively binds to hemoglobin in human blood, forming carboxyhemoglobin, and blocks the transfer of oxygen to tissue cells, which leads to hemic hypoxia. Carbon monoxide is also included in oxidative reactions, disrupting the biochemical balance in tissues.
In other words, when carbon monoxide is inhaled, its molecules “take” the place of oxygen in a person’s blood, which can lead to his death.
Signs of carbon monoxide poisoning
The first symptoms of carbon monoxide poisoning are headache, tinnitus, tachycardia, dizziness and nausea.
If the concentration of carbon monoxide in the room increases, then more severe nausea, difficulty breathing, a feeling of lack of air and shortness of breath appear. If a person has any serious diseases, including the respiratory system or the cardiovascular system, then pathological reflexes, disturbances in mental activity, and also manifestations of agitation or stupor, even coma, are possible. Often there is a short-term loss of consciousness (for a period of up to twenty minutes).
When the concentration of carbon monoxide continues to increase, the victim begins to experience drowsiness, or, conversely, excitability. Coordination of movement and the appearance of hallucinations may be impaired. If first aid is not provided, death can occur within half an hour.
If the air contains more than 1% CO (and this is a very high concentration), after inhaling this substance, death can occur after two to three minutes.
First aid measures for carbon monoxide poisoning
1. If you entered a room and immediately found it difficult to breathe (in the absence of smoke) or felt strong smell gas (in the event of a domestic gas leak), and you see that there are people in the room who need help, you should leave the door to the room open and call someone for help (including by calling 01 or 03).
2. If you decide to provide assistance to the victims yourself:
— place a piece of cloth moistened with water to your face and only after that quickly enter the room;
....- if possible, open the windows immediately; if not, try to take the victim out of the room into fresh air as quickly as possible;
- Having carried out the victims, quickly leave the room and wait for the specialists to arrive.
Help for a carbon monoxide victim:
- if the victim is conscious, provide continuous access to fresh air and short-term inhalation of ammonia, rub the body. Call an ambulance;
- if the victim is unconscious, it is necessary to immediately begin artificial respiration until he regains consciousness or until the ambulance arrives;
- if a victim of carbon monoxide came to his senses, but was unconscious for a long time, then he must be urgently transported to a medical facility and treated. Carbon monoxide poisoning is determined by a blood test.
Attention! Be sure to tell your emergency physician if you suspect carbon monoxide poisoning.
Is it worth eliminating the source of carbon monoxide yourself, before specialists arrive?
It all depends on whether you were able to immediately see this source of carbon monoxide and determine that it was the cause of the incident. Then you should really evaluate your capabilities, that you can eliminate this cause within a few tens of seconds (!!!). For example, you can quickly close the valve on gas pipe, if carbon monoxide was formed due to improper combustion of gas due to lack of air. But if the reason for filling the room with carbon monoxide was a wood-burning stove with a clogged chimney, you will not be able to quickly deal with the problem.
Another case - carbon monoxide formed in a dense closed garage due to the car engine being left running. Here, to begin with, it will be enough to open the gate wide enough to reduce the concentration of carbon monoxide, and then you should turn off the car engine.
Remember that the longer you are in a room with carbon monoxide, the more likely it is that you yourself will become a victim of it.
How to prevent the formation of carbon monoxide and subsequent poisoning
1. Comply with fire safety requirements.
2. Do not violate the rules for operating stove heating: untimely closing of the stove damper, insufficient access of fresh air to the firebox, poor draft can easily cause the formation of carbon monoxide in the room.
3. Before using the stove, check the draft in the chimney, as well as its integrity and absence of cracks (including in the entire structure of the stove).
4. Don't spend Maintenance car in a garage or room with poor ventilation.
5. Never sleep in a car with the engine running in a garage.
6. Do not use charcoal grill in closed gazebo barbecue with poor ventilation.
7. In a room where an autonomous gas boiler is installed, as well as gas stove, during their operation the window should be slightly open (especially if there are plastic windows, in the frames of which there are no gaps through which air from the street would penetrate into the room).
Carbon monoxide poisoning can be more easily avoided by using a self-contained alarm or carbon monoxide detector in your home. If the concentration of carbon monoxide in a residential building or technical room exceeds the permissible level, the sensor signals, warning of danger. Carbon monoxide alarms are electrochemical sensors designed to continuously monitor the level of CO in indoor air and respond with sound and light signals to increased levels of carbon monoxide concentration.
Facts about the dangers of carbon monoxide
Cases of carbon monoxide poisoning are, unfortunately, not that rare. Here is one of the latest - dated January 14, 2015 - Tragedy in Kuban: 9 people were poisoned by carbon monoxide, 2 children died:
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