Journey through the globe to a very small and lowly populated village Darweze located In the middle of the Karakum desert in Turkmenistan, a place recorded to have two characteristic large openings in the ground. One called the Turquoise Lake Crater and the other the Darvaza gas crater AKA Door to hell, each having two opposite elements, Water and Fire respectively.

^{Darvaza Gas Crater. Flickr}

Many classify the gas crater as weird, bizarre, wondrous because it is like a large bowl constantly emitting burning flames in the ground and the fact that seeing such large hole glowing in the dark is unbelievable, is acknowledged. Nevertheless, it isn't completely outlandish because almost the same thing (flaring) happens in chemical plants and petroleum refineries, except that it is controlled and doesn't happen on a large scale. And also it isn't the actual door to hell but the earth itself. In fact, a man named George Kourounis has set foot at the bottom before. So don't expect to sight Hades there :)

^{Google Earth Images: The door to hell}

A BRIEF HISTORY AND GEOGRAPHY

Darvaza believed to be rich in natural gas, with one of the largest reserves, was surveyed by engineers from the soviet union. To harness the oil in the region for energy creation, they set out to drill a spot confirmed to contain natural gas, but there was a mishap. The ground underneath collapsed and a sinkhole of depth 20 meters and an approximate diameter of 69 meters was created, swallowed their equipment but there was no official report of human casualties.

^{Screenshot: Google earth images}

Records have it that the crater was abandoned, and not set on fire until more than a decade passed away. The amount of gas released was very high regarding its consistency. Nature within that region was threatened as the gas percentage in the atmosphere increased the level of air pollution. The flammability of the released compounds was definitely considered alongside their greenhouse effects. So engineers set out again with wrong anticipations and miscalculations to burn off the gas. The burning was expected not to exceed a short period of weeks but it has been burning for more 45 years now without no sign of quenching. This constant burning has resulted in an artificial tourist centre for travellers, though measures have been taken to extinguish it but to no avail.

Flaring, in comparison with this phenomenon, is as well a continual burning process, both happening with the reason of destroying the excess extremely flammable hydrocarbons which are vented out of the ground. In chemical plants and refineries, the flare-stack, a device consisting of a large network of pipes is known to be the last line of defence as it reduces the pressure in the whole system. In both cases, gases which cannot be used are all burnt off as an effort to prevent threats against nature in general, the health of plants and animals and the earth's atmospheric balance. This contributes to the alleviation of global warming and respiratory problems such as asthma, etc.

ATMOSPHERIC NATURAL GAS.

CLEANEST FOSSIL FUEL

Natural gas is a mixture of lower saturated hydrocarbons, created from highly decomposed organic matter within the earth for megaannums. Its compositions vary in percentage concentrations, with methane(CH₄) as its primary constituent having a percentage range of 80 to 90%. Other constituents include butane, propane, etc and it may sometimes also contain minute amounts of carbon dioxide, Hydrogen sulphide, and Nitrogen oxide.

Since natural gas is gotten from organic matter, it is classified as a fossil fuel, with many uses commercially, industrially and domestically. It burns to provide energy for cooking, the creation of electricity, heating, in manufacturing industries, etc.

Different means and methods have been explored with the purpose of increasing the percentage use of reliable energy and reducing the dependency on non-renewable energy like oil, coal and gas. Regardless of this fact, natural gas among all fossil fuels is considered the cleanest because it releases less harmful substances when burnt. This is because.

• The atmospheric release of CO₂, by burning natural gas compared to coal and oil is very low, almost by half.

• Since impurities in natural gas are low compared to oil and coal, emissions of sulphur dioxide and nitrogen dioxide are negligible. This is because the molecules of coal and oil are complex and more compact with a high carbon ratio making them possible to have high hydrogen and sulphur content.

• Natural gas contributes less in smog and soot formation, alleviating vision and health issues

For all these reasons, the usage of natural gas has increased, especially in developed and developing countries. New plants harness this and old plants are switching their source of energy. But there is a bad side. Just as the demand and production of this fuel escalate, so also does its emission and leakage into the atmosphere during transmission and distribution. As this increases, it aggravates the danger of offsetting climatic benefits. This is the reason why excess gases which cannot be used during production is burnt off in the flare stack.

^{Graph showing atmospheric content of methane of the U.S. Wikimedia Commoms}

Natural gas and greenhouse effect

The greenhouse effect is a natural phenomenon which involves warming up of the earth by the radiation of already absorbed and trapped rays from the sun in some certain gases. Methane the principal component of natural gas is among these gases, also including carbon dioxide, water vapour, hydrofluorocarbons, chlorofluorocarbons, etc. Among all these, the leading is Carbon dioxide because of its natural existence in the atmosphere in very large amounts.

Greenhouse gases are very necessary for the continuity of nature because they prevent the earth from freezing by trapping heat which is not allowed to escape into space. But, even if it is purely a natural phenomenon, it has been intensified over time. Their presence in the atmosphere has increased in proportion to the increasing rate of urbanization and industrialization, pushing life survival to a threshold of imminent crisis. The earth's atmospheric balance scale has tilted as overheating increases, and it continues to increase the rate of global warming.

Earlier on it was related that natural gas through the flare-stack is burnt off to mollify global warming when narrowed down to the greenhouse effect, but when hydrocarbons—methane specifically burns, it gives water vapour, carbon dioxide and energy, which are still greenhouse gases.

CH₄ + 2O₂ ⟹ CO₂ + 2H₂O + Energy

This would bring up the perplexity of how methane's burning would reduce global warming unless a comparison is done between the CH₄ and CO₂

• Methane has an approximate half-life of 9 years while that of carbon dioxide can't be accurately calculated. Although it is more than three times that of methane, which means carbon dioxide lasts longer in the atmosphere.

• Among gases in general, organic gases are the most complex. Reason being that almost all organic compounds are liquids or solids making them have compact molecules. methane is a saturated hydrocarbon(single bond) with a tetrahedral covalent shape, while carbon dioxide is just a linear covalent molecule.

O=C=O

^{linear covalent bond
Methane tetrahedral single covalent bond Wikimedia Commons}

Despite the fact that CO₂ lasts way longer than CH₄ in the atmosphere, the global warming potential(GWP) of CH₄ is greater than that of CO2. GWP is the measure of how much heat a greenhouse gas traps in the atmosphere in comparison with the amount trapped by the equal mass of CO₂ within a time interval. In a period of hundred years, the GWP of methane is 28, that is mass, m of CH₄ traps 28 times more heat than mass, m of CO₂ in 100 years. Within this period, the heat trapped has a greenhouse effect 32 times that of CO₂. Also in 20 years period, its GWP is 104. This is definitely because the binding energy of methane greatly surpasses that of carbon dioxide, thereby storing more heat energy. Comparisons can't be done with water vapour because it's GWP can't be accurately calculated.

Bottom-line, in greenhouse effect, methane is a more potent gas than carbon dioxide. As a matter of fact, carbon dioxide has the least GWP among all greenhouse gases.

So when you travel through or to the Karakum desert, expect the excitement of seeing this very large burning crater. But remember the reason why it is burning, not as an opening to the real hell, but just for nature's sake.

REFERENCES

This Hellish Desert Pit Has Been On Fire for More Than 40 Years | Gas flare-Wikipedia | Turkmenistan hopes 'Door to Hell' will boost tourism | Darvaza Gas Crater-Wikipedia | Atmospheric methane-wikipedia | Global warming potential-Wikipedia | Natural Gas Is The Cleanest Fossil Fuel | Environmental impacts of natural gas