Why not add very smelly mercaptan to domestic piped natural gas

In the past, odorants such as ethyl mercaptan were used.

Tetrahydrothiophene is now used.

Tetrahydrothiophene (THT), also known as thiacyclopentane, tetramethyl sulfur, sulfide elongbutyl, tetrahydrothiazabenz, is a sulfur-containing saturated heterocyclic compound obtained by catalytic hydrogenation of thiophene, thiophene is reduced to tetrahydrothiophene, no longer has a conjugated system and aromaticity, so tetrahydrothiophene shows the properties of general thioether, and is easily oxidized to sulfoxide and sulfone (sulfobutylsulfone).

Tetrahydrothiophene is a colorless, transparent and volatile liquid, insoluble in water, miscible in ethanol, ether, benzene, and acetone. It has a strong unpleasant odor, the odor it produces is stable, not easy to dissipate, it can be smelled in the air, it is not corrosive to gas equipment, transportation pipeline gaskets and other materials, and it will not produce habitual passivation to the human sense of smell, so it is used as a leakage warning agent for gaseous fuels such as city gas and natural gas, and is added to gaseous fuels in small quantities, and the current domestic market requires about 400 tons of tetrahydrothiophene per year, mainly relying on imports. Tetrahydrothiophene has an anesthetic effect.

When mice are inhaled and poisoned, motor excitement, ataxia, anesthesia, and finally death occur. In the chronic poisoning experiment, the mice showed abnormal behavior, weight gain and liver function changes. In addition, it is also used as a raw material for medicine, pesticides and organic synthesis.

The state mandates that domestic piped natural gas must be odorized, and general enterprises will add it. However, it is not excluded that some companies are negligent in their work, leakage and odor, or the amount added is too small to smell the odor. For the sake of the safety of life and property of yourself and your family, you can report the situation to the gas business company or to the gas department.

According to the requirements of the city gas design code, it needs to be added, specifically about 20mg of tetrahydrothiophene (THT) per square meter, reaching the second level of odor.

This is a "smell" specially artificially added by the gas company for safety reasons in order to make the odorless gas leak so that people can be found in time - tetrahydrothiophene THT (scentineltm T) is the main natural gas odorant used in the world. After adding it to the gas, if the indoor gas leaks, it can be detected in time and take measures to avoid fires or accidents caused by gas.

Ethyl mercaptan has a foul smell that can serve as a warning if an air leak occurs. Let you discover.

In order to detect a leak as soon as possible.

Natural gas itself has no color and no smell, and unpleasant substances are added to domestic pipeline natural gas in order to facilitate timely detection of gas leakage to avoid major injury.

It is because there is a special odor agent added to the natural gas, and the leakage can be detected in time.

Natural gas has no odor, and household gas is a odorant specially added to detect leaks in time.

Generally, 50-200 ppm methyl mercaptan is added to natural gas and injected under pressure.

Because natural gas is colorless and odorless, it can be very dangerous if it leaks undetected. After adding such substances, if there is a leak, people will find it in time to ensure that it is safe to use.

Principles of natural gas odorization:

Gas leaks should be detectable when they reach 20% of the lower limit (i.e. 1% concentration).

The odorization standard is generally 20mg m, and it is recommended to double the odorization in winter.

This should be done by oil and gas suppliers in order to detect leaks as early as possible.

Natural gas itself is colorless and odorless, and if it is not odorized, it will not smell the air leaking in the home. It can easily cause, poison or deflagrate. Causing a major accident.

Since gas has no odor, why does pipe gas and liquefied petroleum gas used for cooking have an unpleasant odor? This is the role of mercaptan, which acts as an "alarm" for the gas. Because carbon monoxide is a colorless, odorless gas, it is not easily noticed.

And with the smell can make people alert, immediately take measures to prevent the occurrence of **, fire and poisoning accidents.

So, does natural gas smell good? This has to be said in terms of its composition. Natural gas is a mixture of many gases, the main component is methane, which accounts for about 80 90 by volume, and more can reach 98.

Natural gas burns more completely, but carbon monoxide and carbon dioxide are also produced. Therefore, it still needs "mercaptans". Households that burn oil and gas directly have higher levels of formaldehyde and NOx indoors, accompanied by eye stinging or other uncomfortable sensations.

So, if you use natural gas at home, you should also pay attention to indoor ventilation. It is recommended that you leave the windows open for 5 to 10 minutes in the morning to ventilate and refresh your mind.

Mercaptan is a substance with a peculiar odor that, when added, may serve as a reminder if natural gas leaks.

Natural gas itself is colorless and odorless, and it has a foul smell after adding mercaptan or tetrahydrothiophene, which is convenient for people to find gas leakage in time and avoid accidents.

When there is a leak in the pipeline, it plays the role of alarm.

It does smell like rotten eggs, and the odorous substances are generally tetrahydrothiophene and other substances. Natural gas contains less sulfide and is difficult to detect.

It is similar to the smell of the original gas, and it can be clearly felt.

The foul smell is more pungent.