Definition
Natural gas is a mineral in the gaseous state. It is widely used as a fuel. But natural gas itself is not used as a fuel, its components are separated from it for separate use.
Composition of natural gas
Up to 98% of natural gas is methane, it also includes methane homologues - ethane, propane and butane. Sometimes there may be carbon dioxide, hydrogen sulfide and helium. This is the composition of natural gas.
Physical Properties
Natural gas is colorless and odorless (if it does not contain hydrogen sulfide), it is lighter than air. Flammable and explosive.
Below are more detailed properties of natural gas components.
Properties of individual constituents of natural gas (consider the detailed composition of natural gas)
Methane(CH4) is a colorless, odorless gas, lighter than air. Flammable, but still it can be stored with sufficient ease.
Ethane(C2H6) is a colorless, odorless and colorless gas, slightly heavier than air. Also combustible, but not used as a fuel.
Propane(C3H8) is a colorless, odorless gas, poisonous. It has a useful property: propane liquefies at low pressure, which makes it easy to separate it from impurities and transport it.
Butane(C4H10) - similar in properties to propane, but has a higher density. Twice as heavy as air.
Carbon dioxide(CO2) is a colorless, odorless gas with a sour taste. Unlike the other components of natural gas (with the exception of helium), carbon dioxide does not burn. Carbon dioxide is one of the least toxic gases.
Helium(He) - colorless, very light (the second of the lightest gases, after hydrogen) without color and odor. Extremely inert, under normal conditions does not react with any of the substances. Does not burn. It is not toxic, but at elevated pressure it can cause anesthesia, like other inert gases.
hydrogen sulfide(H2S) - colorless heavy gas with the smell of rotten eggs. Very poisonous, even at very low concentrations it causes paralysis of the olfactory nerve.
Properties of certain other gases that are not part of natural gas but have uses similar to those of natural gas
Ethylene(C2H4) - A colorless gas with a pleasant smell. It is similar in properties to ethane, but differs from it in lower density and flammability.
Acetylene(C2H2) is an extremely flammable and explosive colorless gas. With strong compression, it can explode. It is not used in everyday life due to the very high risk of fire or explosion. The main application is in welding work.
Application
Methane used as fuel in gas stoves.
propane and butane as fuel in some vehicles. Lighters are also filled with liquefied propane.
Ethane it is rarely used as a fuel, its main use is the production of ethylene.
Ethylene is one of the most produced organic matter in the world. It is a raw material for the production of polyethylene.
Acetylene used to create a very high temperature in metallurgy (reconciliation and cutting of metals). Acetylene it is very combustible, therefore it is not used as a fuel in cars, and even without this, the conditions for its storage must be strictly observed.
hydrogen sulfide, despite its toxicity, is used in small quantities in the so-called. sulfide baths. They use some of the antiseptic properties of hydrogen sulfide.
Main useful property helium is its very low density (7 times lighter than air). Helium fill balloons and airships. Hydrogen is even lighter than helium, but at the same time combustible. Helium balloons are very popular among children.
Toxicity
Carbon dioxide. Even large amounts of carbon dioxide do not affect human health in any way. However, it prevents the absorption of oxygen when the content in the atmosphere is from 3% to 10% by volume. At this concentration, suffocation and even death begin.
Helium. Helium is completely non-toxic under normal conditions due to its inertness. But with increased pressure, the initial stage of anesthesia occurs, similar to the effect of laughing gas *.
hydrogen sulfide. The toxic properties of this gas are great. With prolonged exposure to the sense of smell, dizziness and vomiting occur. The olfactory nerve is also paralyzed, so there is an illusion of the absence of hydrogen sulfide, but in fact the body simply does not feel it anymore. Hydrogen sulfide poisoning occurs at a concentration of 0.2-0.3 mg / m3, a concentration above 1 mg / m3 is fatal.
combustion process
All hydrocarbons, when fully oxidized (excess oxygen), release carbon dioxide and water. For example:
CH4 + 3O2 = CO2 + 2H2O
With incomplete (lack of oxygen) - carbon monoxide and water:
2CH4 + 6O2 = 2CO + 4H2O
With an even smaller amount of oxygen, finely dispersed carbon (soot) is released:
CH4 + O2 = C + 2H2O.
Methane burns with a blue flame, ethane - almost colorless, like alcohol, propane and butane - yellow, ethylene - luminous, carbon monoxide - light blue. Acetylene - yellowish, strongly smokes. If you have a gas stove at home and instead of the usual blue flame you see yellow, you should know that methane is diluted with propane.
Notes
Helium, unlike any other gas, does not exist in a solid state.
Laughing gas is the trivial name for nitrous oxide N2O.
Comments and additions to the article - in the comments.
Liquid and gaseous. Almost any liquid can acquire each of the remaining two. Many solid bodies when melted, evaporated or burned, they can replenish the content of the air. But not every gas can become a component of solid materials or liquids. known different types gases that differ from each other in properties, origin and application features.
Definition and properties
A gas is a substance that is characterized by the absence or minimum value intermolecular bonds, as well as the active mobility of particles. The main properties that all types of gases have:
- Fluidity, deformability, volatility, striving for maximum volume, the reaction of atoms and molecules to a decrease or increase in temperature, which is manifested by a change in the intensity of their movement.
- They exist at a temperature at which an increase in pressure does not lead to a transition to a liquid state.
- Easily compressed, decreasing in volume. This simplifies transport and use.
- Most are liquefied by compression within certain limits of pressure and critical heat values.
Due to the research inaccessibility, they are described using the following basic parameters: temperature, pressure, volume, molar mass.
Field classification
AT natural environment all kinds of gases are found in air, land and water.
- Air components: oxygen, nitrogen, carbon dioxide, argon, nitric oxide with admixtures of neon, krypton, hydrogen, methane.
- AT earth's crust nitrogen, hydrogen, methane and other hydrocarbons, carbon dioxide, sulfur oxide and others are in a gaseous and liquid state. There are also gas deposits in the solid fraction mixed with water layers at pressures of about 250 atm. at relatively low temperatures(up to 20˚С).
- Reservoirs contain soluble gases - hydrogen chloride, ammonia and poorly soluble gases - oxygen, nitrogen, hydrogen, carbon dioxide, etc.
Natural reserves far exceed the possible number of artificially created ones.
Flammability classification
All types of gases, depending on the behavioral characteristics in the processes of ignition and combustion, are divided into oxidizers, inert and combustible.
- Oxidizing agents promote combustion and support combustion, but do not burn themselves: air, oxygen, fluorine, chlorine, nitrogen oxide and dioxide.
- Inert ones do not participate in combustion, however, they tend to displace oxygen and influence the decrease in the intensity of the process: helium, neon, xenon, nitrogen, argon,
- Combustibles ignite or explode when combined with oxygen: methane, ammonia, hydrogen, acetylene, propane, butane, ethane, ethylene. Most of them are characterized by combustion only under conditions of a certain composition of the gas mixture. Due to this property, gas is the type of fuel, by far the most common. In this capacity, methane, propane, butane are used.
Carbon dioxide and its role
It is one of the most common gases in the atmosphere (0.04%). At normal temperature and atmospheric pressure has a density of 1.98 kg/m 3 . May be in solid or liquid state. The solid phase occurs at negative heat and constant atmospheric pressure, it is called "dry ice". The liquid phase of CO 2 is possible with increasing pressure. This property is used for storage, transportation and technological applications. Sublimation (transition to gaseous state from a solid, without an intermediate liquid phase) is possible at -77 - -79˚С. Solubility in water in the ratio 1:1 is realized at t=14-16˚С.
Types of carbon dioxide are distinguished depending on the origin:
- Waste products of plants and animals, emissions from volcanoes, gas emissions from the bowels of the earth, evaporation from the surface of water bodies.
- The results of human activities, including emissions from the combustion of all types of fuel.
As a useful substance, it is used:
- in carbon dioxide fire extinguishers.
- In cylinders for arc welding in a suitable CO 2 environment.
- In the food industry as a preservative and for carbonation of water.
- As a refrigerant for temporary cooling.
- in the chemical industry.
- in metallurgy.
Being an indispensable component of the life of the planet, man, the operation of machines and entire factories, it accumulates in the lower and upper layers atmosphere, delaying the release of heat and creating a "greenhouse effect".
and his role
Among the substances of natural origin and technological purposes, there are those that have a high degree combustibility and calorific value. The following types of liquefied gas are used for storage, transportation and use: methane, propane, butane, as well as propane-butane mixtures.
Butane (C 4 H 10) and propane are components of petroleum gases. The first one liquefies at -1 - -0.5˚С. Transportation and use in frosty weather of pure butane is not carried out due to its freezing. Liquefaction temperature for propane (C 3 H 8) -41 - -42˚C, critical pressure - 4.27 MPa.
Methane (CH 4) - the main component. Types of gas source - oil deposits, products of biogenic processes. Liquefaction occurs through gradual compression and heat reduction to -160 - -161˚С. At each stage, it is compressed 5-10 times.
Liquefaction is carried out in special plants. Propane, butane, as well as their mixture for domestic and industrial use are produced separately. Methane is used in industry and as a fuel for transport. The latter can also be issued in compressed form.
Compressed gas and its role
AT recent times compressed natural gas became popular. If only liquefaction is used for propane and butane, then methane can be produced both in a liquefied and in a compressed state. Gas in bottles high pressure 20 MPa has a number of advantages over the well-known liquefied.
- High evaporation rate, including at negative air temperatures, absence of negative accumulation phenomena.
- More low level toxicity.
- Complete combustion, high efficiency, no negative impact on equipment and atmosphere.
Increasingly, it is used not only for trucks, but also for cars, as well as for boiler equipment.
Gas is an inconspicuous, but indispensable substance for human life. The high calorific value of some of them justifies the widespread use of various components of natural gas as a fuel for industry and transport.
Exist., m., use. comp. often Morphology: (no) what? gas and gas, why? gas, (see) what? gas what? gas, what? about gas and on gas; pl. what? gases, (no) what? gases, why? gases, (see) what? gases, what? gases, what? about gases 1. Gas is ... ... Dictionary Dmitrieva
COLORLESS- COLORLESS, colorless, colorless; colorless, colorless, colorless. 1. Having no color, coloring. colorless gas. 2. trans. Unremarkable, unremarkable, unoriginal. Colorless style. Explanatory Dictionary of Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary of Ushakov
colorless- oh, oh; ten, tna, tno. 1. Having no color, pronounced color. B. gas. Second liquid. B. varnish. Used eyes, hair. Whoa face. 2. Deprived of originality, expressiveness; unremarkable, unremarkable. B. story. Second role. Whoa life. ◁… … encyclopedic Dictionary
colorless- oh, oh; ten, tna, tno. see also colorless, colorless 1) Having no color, pronounced color. Colorless gas. Second liquid. Colorless/tny varnish. B s… Dictionary of many expressions
Carbon Dioxide, Carbon Dioxide Gas- a colorless gas formed in the tissues as a result of metabolism and carried with the bloodstream to the lungs, from where it is exhaled when breathing (an increase in the concentration of this gas in the blood stimulates the breathing process). Small amounts of carbon dioxide ... ... medical terms
Carbon monoxide- Carbon monoxide General Systematic name Carbon monoxide Chemical formula... Wikipedia
Laughing gas- Nitric oxide(I) General Systematic name Nitric oxide(I) Chemical formula N2O Rel. molek. weight 44 a. e. m ... Wikipedia
Marsh gas or methane- (also methyl hydrogen, formene) saturated hydrocarbon composition CH4, the first member of the CnH2n + n series, one of the simplest carbon compounds, around which all the others are grouped and from which can be produced through the substitution of atoms ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron
Carbon dioxide- Carbon dioxide Other names carbon dioxide, carbon dioxide, dry ice (solid) Formula CO2 Molar ... Wikipedia
STO Gazprom 5.12-2008: Combustible natural gas. Determination of sulfur-containing components by chromatographic method- Terminology STO Gazprom 5.12 2008: Combustible natural gas. Determination of sulfur-containing components by chromatography: carbonyl sulfide COS: Toxic, colorless gas, sometimes present in HGP. Definitions of the term from various documents: ... ... Dictionary-reference book of terms of normative and technical documentation
Carbon dioxide- carbon dioxide (a. carbon dioxide; n. Kohlensaure, gasformige Kohlensaure, Kohlendioxyd; f. gaz carbonique; and. gas carbonico), carbonic anhydride (CO2). U. g. colorless gas with a slightly acidic taste and odor; density relative to ... ... Geological Encyclopedia
