Earlier, when refining oil, enterprises were forced to burn liquid methane using flares, as they were unable to transfer condensate for subsequent petrochemical processing. Now they have learned to transport it and use it in many areas of industry. At the same time, it is well stored and does not form harmful impurities during combustion.
Physical and chemical properties of methane
Methane is one of the simplest hydrocarbons. It is lighter than air, non-toxic, poorly soluble in water, and has no perceptible odor. It is believed that methane is not dangerous to humans, but there are cases of its effects on the central and autonomic nervous system. Accumulating indoors, at a concentration in the air from 4% to 17% it becomes explosive. Therefore, in order to detect it by a person (without instruments), special substances are often added to methane that resemble the smell of gas. Refers to greenhouse gases. In methane, weak narcotic properties are manifested, which are weakened by low solubility in water.
By origin, as a result of compounds with various substances and chemical reactions, it is divided into:
- biogenic (organic);
- abiogenic (inorganic);
- bacterial (vital activity of microorganisms);
- thermogenic (thermochemical processes).
This gas is also obtained in the laboratory by heating soda lime or anhydrous sodium hydroxide with frozen acetic acid.
Methane in the liquid state takes up 600 times less volume than in the gaseous state. Therefore, for ease of transportation and storage, it is subjected to liquefaction. Liquid methane is a colorless, odorless liquid. It retains almost all properties of the gas. The critical pressure of liquid methane is 4.58 MPa (the minimum at which it turns into a liquid).
Existence in nature
Methane is a constituent and main constituent of the following gases:
- natural (up to 98%);
- oil (40-90%);
- marsh (99%);
- miner (35-50%);
- mud volcanoes (more than 94%).
It is also contained in the water of the oceans, lakes, seas. It is present in the atmosphere of such planets as Earth, Saturn, Jupiter, Uranus, and in the surface gases of the Moon. A large amount is found in coal seams. This makes underground mining an explosive activity.
LNG technology
Pure methane is obtained from natural gas by removing other components from it: ethane, propane, butane and nitrogen. To obtain liquid methane, the gas is compressed and then cooled. Liquefaction processproduced in cycles. At each stage, the volume will decrease up to 12 times. It turns into a liquid in the last cycle. Different types of plants are used for liquefaction, among them:
- throttle;
- turbine-vortex;
- turbo-expander.
The following schemes can be used:
- cascading;
- expansion.
Three cooling agents are used in the cascade scheme. In this case, the temperature of liquid methane decreases in stages. This technology requires large capital expenditures. At present, this process has been improved and a mixture of refrigerants (ethane and propane) has been used immediately. Such a scheme has become self-cooling, since these substances are obtained from liquefied natural gas. Costs have decreased slightly, but remain high.
When applying the expansion scheme, more economical centrifugal machines are used. The mixture is preliminarily cleaned from water and other contaminants and liquefied under pressure due to heat exchange with a cold expanded gas stream. However, this process requires more energy than with a cascade scheme (by 25-35%). But at the same time, capital costs for compressors and equipment operation are saved.
The temperature of the liquid methane obtained from the above process averages 162 degrees.
Methane applications
The scope of methane, both in gaseous and liquid state, is very extensive. It is used as a fuel, as a raw material for industry, in everyday life, inas anabolic steroids for building muscle mass.
Incomplete combustion of methane produces soot, which is widely used in industry: in the production of rubber, stamp paint, shoe polish, etc. They are also used to produce hydrocyanic and acetic acid, methanol, acetylene, ammonia, carbon disulfide, as fuel gas (eternal flame).
Liquid methane is used as motor fuel for cars. It has an octane rating 15% higher than that of gasoline, as well as high calorific value and anti-knock properties. According to reviews, liquid methane burns out almost completely, and with the correct installation of the appropriate equipment on the car, quite significant savings occur compared to gasoline (when traveling long distances).
This gas is actively used for the production of drugs that increase muscle mass. On its basis, such products as Dianoged, Danabol, Nerobol are produced, which are in the greatest demand. It is believed that these drugs have a positive effect on the human body:
- strengthen bones;
- stimulate the formation of sexual characteristics;
- burn fat;
- increase stamina;
- accelerate protein synthesis.
However, it is important to remember that all drugs have side effects, so they should be taken under the supervision of a doctor.
Based on the above, we can conclude that the productionliquid methane is a very promising area of modern industry.
