Natural gas is used today in many residential and industrial applications, mainly for electricity generation, heating, cooking and as a fuel source for vehicles.
What is Natural Gas?
Natural gas is a fossil fuel in gaseous state that consists mainly of methane (CH4), and other forms of alkanes such as ethane, propane, n-butane, n-pentane etc., but also a very small percentage of CO2, nitrogen, hydrogen sulfide and even helium.
When burning, natural gas releases less harmful emissions into the atmosphere than coal and oil, and this is the reason why natural gas is considered a cleaner fossil fuel.
Natural gas is not very different from crude oil because the alkanes contained by natural gas can also be found in oil.
Today, natural gas is a pretty abundant resource on the planet, mostly due to the recent “fracking boom”, which has released the deposits of oil and natural gas from the underground rock.
In the residential applications, natural gas is used for cooking and as a heat source for homes and buildings such as schools, office buildings, hospitals, restaurants, hotels, motels and so on.
Natural gas is more practical than wood or pellets for residential heating because a central heating system that uses natural gas as an energy source will automatically provide both heat and warm water.
A wood or pellet boiler will also provide heating and warm water, but the wood boiler needs to be refuelled every day, and the pellet boiler every week.
The boiler using natural gas will work day and night without any intervention from the owner because the fuel comes from the grid.
Using wood as a heating source during the winter can be cheaper than using natural gas, but natural gas is preferred in many countries because is more practical and is cleaner than oil and coal.
Natural Gas Used to Generate Electricity
Besides heating, cooking and car fuel, natural gas is also used to generate electricity.
1. Steam Generation Units
These units are using natural gas to heat water and the resulting steam is used to spin a turbine that will generate electricity.
2. Centralized Gas Turbines and Combustion Engines
These units are using the hot gases resulted from burning fossil fuels such as natural gas to spin a turbine and produce electricity.
3. Combined Cycle Units
Today, many power plants using natural gas are ‘combined-cycle’ units.
These units consist of both a gas turbine and a steam unit.
The gas turbine will produce electricity by burning natural gas and using the burning gases to spin the turbine, and the waste heat resulted from the gas turbine will be used by the steam unit to produce electricity the same way like a steam turbine.
4. Distributed Generation
Distributed generation is usually used at residential, commercial, and industrial sites where can be placed individual and smaller sized electric generation units that will work like small scale power plants that are primarily powered by natural gas.
These individual units can use a small gas turbine or combustion engine units, or can rely on natural gas fuel cells.
Distributed generation allows the companies to produce their own energy, which is cheaper than the energy provided by the grid.
Distributed generation can power small companies with electricity, but also entire factories by using larger units.
Natural gas can be used as compressed natural gas (CNG) or as liquified petroleum gas (LPG) to power vehicles.
Advantages of Natural Gas
Natural gas has many advantages as fossil fuel, but also a few disadvantages.
1. Is Friendlier with the Environment
Natural gas is one of the cleanest fossil fuels known today, and is considered the best choice to replace the dirty fossil fuels such as coal and oil, for a cleaner future.
While burning, natural gas releases 45% less harmful emissions than coal, and 30% less harmful emissions than oil, so it is considered one of the cleanest fossil fuels.
2. Natural Gas is a Reliable Energy Source
While other energy sources are intermittent (solar, wind, etc.), natural gas can provide a steady and reliable source of low-carbon power when needed.
Natural gas is also a reliable source of heat and warm water during the winter that is still working even if the weather conditions are very harsh.
3. Natural Gas is a Cheap Energy Source
Using natural gas as an energy source is cheaper than using other fossil fuels for electricity and heating.
Coal is also a very cheap source of electricity and heat, but due to its high level of pollution produced while burning, coal cannot be considered an alternative to natural gas.
In very poor countries, where natural gas might not be accessible to everyone, coal and wood (illegally cut from the forest) are usually used as the main heating source.
4. Can Be Easily Transported or Transferred
Natural gas is transported via sea in large tankers and on land in small tankers or through a complex network of pipelines.
On land, natural gas can be easily transferred from the supplier to residential areas using the pipeline network.
The pipeline network for natural gas is usually painted in yellow color, and is built at a certain height above the ground to be easily accessible in case of a leak.
5. Is a Cheap Source For Producing Hydrogen
Hydrogen is a very abundant element in the universe, but here on the planet producing hydrogen is not a cheap process.
However, natural gas is considered one of the cheapest sources of fossil fuel used to produce hydrogen.
6. Natural Gas is a Very Complex Fuel
Natural gas is a very complex fuel because is used today for heating, cooking and drying, to produce low carbon electricity and to power vehicles with a cheaper and cleaner fuel (LPG) than gasoline and diesel.
Disadvantages of Natural Gas
Natural gas also has a few disadvantages, but not as fossil fuel.
1. Natural Gas is Non-Renewable and Non-Sustainable
Natural gas is a limited resource that will be depleted in a few decades from now on mostly because natural gas will be used as the main energy source on the planet (instead of coal and oil) in the future.
Natural gas is also non-sustainable and harmful for the environment.
2. Natural Gas is Highly Flammable
Even if it is a cleaner fossil fuel than coal and oil, natural gas is a highly flammable energy source.
Due to this fact, a special odor is added to the gas in order to improve detection in case of a leak (natural gas is an odorless gas).
If there is a leak of natural gas in a room or building the danger of a massive explosion is imminent, and just a spark is enough to ignite the gas and destroy the property, human life and even the neighboring properties.
3. Hydraulic Fracturing for Natural Gas Extraction Can Poison the Underground Fresh Water Resources
Extracting shale gas from the underground rock using the extraction technique called ‘hydraulic fracturing‘ produces a massive contamination of the soil and the underground water sources with dangerous chemicals.
Fracking could also cause small quakes in the area of the well, which affects the life of the people living nearby the extraction point.
4. Uses An Expensive Piping System
Natural gas uses a complex piping system that is pretty expensive to build.
Another issue with the piping system used to transfer natural gas from one place to another can be created by a leak in the system, which is hard and expensive to detect and fix because besides the work required to fix the problem, the leak causes financial loses to the supplier.
Natural gas like all the other finite energy sources, has many advantages and also a few disadvantages, but for the future, we have to make a compromise and use this low carbon fossil fuel as the main source of power on the planet (along with the renewable energy sources) in order to reduce the level of greenhouse gas emissions released into the atmosphere by coal and oil.