Natural gas can be considered today the cleanest fossil fuel available on the planet, that can help our civilization to make the transition from fossil fuels to renewable energy.
Natural gas is already used massively on the planet for energy generation, heating and cooking, and also to run vehicles.
Burning cleaner in air than coal and oil, natural gas is considered today a transitional fuel, which will allow mankind to reduce the use of coal and also reduce the level of water, soil and air pollution on the planet.
Natural Gas Definition
Natural gas can be defined as a fossil energy source that contains a hydrocarbon gas mixture based mainly on methane (CH4), varying amounts of other higher alkanes, and small quantities of carbon dioxide, nitrogen, hydrogen sulfide and even helium.
Natural Gas Formation
Being a fossil fuel like coal and oil, natural gas was formed millions of years ago, when a large number of dead organisms sunk to the bottom of the ocean, where were buried under several deposits of underground rock.
Due to the intense heat and pressure present in the underground rock, the remains of these organisms have been turned into natural gas over a period of millions of years.
Natural Gas Reserves
Natural gas reserves can be found today in reservoirs located in the underground rock, usually in rocks that have tiny spaces between them (pores), which allow them to hold water, natural gas and oil.
Natural gas is trapped underground in the impermeable rock (cap rock) and waits there to be extracted.
Natural Gas Extraction
Conventional natural gas is extracted using drilling wells, while the unconventional forms of natural gas such as shale gas, tight gas, sour gas and coalbed methane have specific extraction techniques such as hydraulic fracturing (fracking), drilling wells into the coal seam, etc.
Oil reservoirs can also contain natural gas, which means that natural gas can be extracted alongside oil.
This type of natural gas is known as associated gas, and today is captured and used instead of being burned or flared as waste gas like in the past.
Natural Gas Processing
Once extracted, natural gas is sent through pipelines (gathering lines) to processing plants where raw natural gas is separated in various hydrocarbons and fluids to produce ‘pipeline quality’ dry natural gas.
The various impurities present in the raw natural gas are removed in four main steps.
- Oil and condensate removal
- Water removal
- Separation of natural gas liquids
- Sulfur and carbon dioxide removal
The purified natural gas obtained this way is then transported through pipelines (feeders) to distribution centers or is stored in underground reservoirs for later use.
For shipping in large tankers all over the planet, natural gas is liquefied (LNG).
Natural Gas Uses
Natural gas is mostly used today for residential and industrial heating, to generate electricity and for cooking.
Natural gas is also compressed and used as fuel in vehicles, as feedstock for fertilizers, to produce hydrogen fuel cells, and in many other chemical processes.
There are two types of natural gas: dry or wet.
Dry gas is gas that contains mostly methane, while wet gas contains in addition to methane, other compounds such as ethane and butane.
These compounds are called ‘natural gas liquids’ or NGLS (ethane, propane, butane, pentane, etc.) and are sold individually for various uses such as in refrigerants and to produce plastics.
Benefits of Natural Gas
Being the cleanest fossil fuel available today, natural gas has many advantages compared to other sources of energy.
1. Is a Low-Carbon Energy Source
Compared to coal and oil, natural gas burns cleaner in the air because it releases only carbon dioxide and water vapor (no soot or sulfur dioxide).
Being a fossil fuel in gaseous state, natural does not affect water or soil, and the air pollution produced while burning natural gas for heating, cooking or energy generation, releases only a small amount of greenhouse gas emissions into the atmosphere, which makes it less harmful for the environment than coal and oil.
2. Is an Affordable Source of Energy
We all know that many developing countries on the planet are trying to grow their economies up to the level of the developed countries by using mainly coal as energy source due to the fact that coal is a cheap source of energy.
However, who wants to dig coal out of the ground today knowing that coal is the main source of air, soil and water pollution on the planet, when we have natural gas that is actually cheaper than coal and burns much cleaner?
3. Is a Reliable Energy Source
Fossil fuels are known for their steady and reliable source of power when needed.
A natural gas power plant can work day and night generating electricity and releasing only half of the carbon emissions produced by a coal-fired power plant with the same output.
4. Is a Great Source of Hydrogen
Methane (CH4) contains in its molecule, four atoms of hydrogen and only one atom of carbon.
We have huge quantities of hydrogen in all the water that covers the planet, however, extracting hydrogen from natural gas using a process called steam-methane reforming, is cheaper than extracting hydrogen from water using the electrolysis process.
5. Is a Transitional Fuel
Being the cleanest fossil fuel available on Earth, natural gas is considered the low-carbon fuel that can help our civilization to make the transition from a society powered mainly by fossil fuels to a green society powered by 100% renewable energy.
Drawbacks of Natural Gas
Being a fossil fuel like coal and oil, natural gas has a few disadvantages caused by the greenhouse gas emissions released during its burn for energy and heat production.
1. Is a Finite Resource
Being a fossil fuel produced during a period of millions years from the dead organisms that have lived in our oceans in the past, natural gas is a finite resource that will run out in about five decades.
This means that our society needs to massively develop the generation capacity for renewable energy (mainly solar and wind) in the next decades, to successfully replace the depleting fossil fuels as the main sources of clean power on the planet.
2. It’s Highly Flammable
Natural gas in its natural state usually has no odor or color, so in order to be able to locate the gas, a chemical called mercaptan is added to give the gas a distinctive smell.
The odor helps us find leaks in pipes and appliances to avoid any possible leakage that could lead to the explosion of the gas.
Natural gas is lighter than air, so in a room with gas leakage, natural gas will rise up to the ceiling.
Propane is heavier than air, and this is the reason why a room with propane leakage, the gas will accumulate near the floor or ground.
The combustion of natural gas requires in the presence of three things: a fuel (natural gas), air (oxygen), and an ignition source (a burning match, a lighter, a spark, etc.).
If any of these three are absent, combustion won’t occur.
Natural gas will burn only if the mixture of gas in the air is between 5% and 15% (range of combustion).
If the concentration of natural gas is less than 5% or above 15% in the air, ignition won’t occur.
Whenever you are in an area where there is a smell of gas leave immediately and call the gas company from a phone located outside the area with gas leakage.
While in the area with gas leakage, don’t use the phone and do not turn on or off any lights or appliances, because doing so can cause an electrical spark that would ignite the gas and produce an explosion.
Stay away from the house or the area with gas leakage until someone from the gas company arrives, and the area is cleared by the fire department or the gas company.
3. Hydraulic Fracturing is Harming the Environment
Shale gas is extracted using a technique called hydraulic fracturing or simply fracking.
The problem with this extraction technique is caused by the chemical substances used in the fluid that fractures the underground rock to release the shale gas trapped there.
More than that, the fracking fluid containing the dangerous chemicals is injected back into the well before sealing the well.
Once injected in the underground rock, the fracking fluid could poison the underground water supplies, which affects the life of the people and the animals living close to the fracking wells.
In addition to that, small quakes could shake the area from time to time, which could destroy the homes located near the fracking station.
4. The Use of Natural Gas Contributes to Global Warming
Despite the fact that natural gas releases a smaller amount of carbon emissions while burning, it is still a fossil resource that pollutes the atmosphere.
Methane (CH4) is a very potent greenhouse gas being 24 times more dangerous in terms of causing the greenhouse effect than CO2.
More than that, during the extraction and the transportation process, a small part of natural gas could escape into the atmosphere and contribute to global warming and climate change.
Final Conclusion
Natural gas development, especially in the United States has increased as a result of the technological advances in horizontal drilling and hydraulic fracturing.
Even if we increase the current consumption of natural gas, the U.S. has reserves of natural gas for at least eight more decades, and the planet for about five decades.
This means that we can rely on natural gas instead of coal for energy generation and heating a few more decades until mankind will massively develop the renewable energy sources (maybe by then will master even the nuclear fusion reaction), and our society will finally become a society that relies 100% on renewable energy.
