We use natural gas as an energy source more than any other fuel. As the fastest growing and cleanest burning fossil fuel, natural gas is responsible for nearly one-third of our total energy demand and almost one-quarter of our electricity generation.
Unless you’re an industry expert, there’s a good chance you’re not familiar with the beyond-the-basics details of natural gas. Read on to get a detailed understanding of the fossil fuel we have come to depend on so heavily.
What Is the Definition of Natural Gas?
If you look at dictionary.com, the definition of natural gas is “a combustible mixture of gaseous hydrocarbons that accumulates in porous sedimentary rocks, especially those yielding petroleum, consisting usually of over 80% methane together with minor amounts of ethane, propane, butane, nitrogen, and, sometimes, helium.”
Whoa, what? That’s a lot to digest. Let’s break down all that information into something a bit easier to understand. We’ll take that definition part-by-part, starting with the four natural gases.
What Main Types of Gas Make Up Natural Gas?
Generally speaking, there are four naturally occurring gases. When mixed in the correct proportions, they create natural gas. They are known as the four natural gases and include the first four alkanes — methane, ethane, butane, and propane.
An alkane is a hydrocarbon where single bonds link together each atom. Hydrocarbons are chemical compounds made up exclusively of carbon and hydrogen atoms. Methane, ethane, butane, and propane — the grouping of alkanes used to compose natural gas — have a lot in common. They are all colorless, odorless, and flammable gases. However, they all have different molecular structures and individual uses.
What Are the 4 Natural Gases?
Methane, a non-toxic gas, is the main ingredient in natural gas, making up over 80% of the mixture. Its chemical formula is CH₄ making it the simplest form of hydrocarbon molecules. Since methane is odorless, smelly sulfur compounds are added to it when it’s used as a gas so that we’re able to detect leaks. When burned, methane emissions release into the atmosphere, where they become greenhouse gas.
Ethane’s chemical formula is C₂H₆ — it’s the only two-carbon alkane. Ethane typically makes up 1% to over 6% of the natural gas mixture, making it the second-largest fossil fuel component. Ethane’s primary use is as a petrochemical feedstock for ethylene production.
A petrochemical feedstock is a material (feedstock) derived from petroleum (petrochemical) for manufacturing countless everyday items. You may even be using a few petrochemical products right now, including batteries, clothing, digital devices, electric vehicle parts, medical equipment, solar panels, wind turbine blades, and the list goes on.
The chemical formula for propane is C₃H₈, which makes it a three-carbon alkane. Small amounts of propane are a component of the natural gas mixture. However, we mainly use it as fuel for grills, portable stoves, buses, taxies, forklifts, and recreational vehicles. In rural areas of the United States, we also use propane for appliances, such as furnaces, laundry dryers, and water heaters. Propane combustion is not as clean as natural gas, but it is much cleaner than gasoline.
Although we consider butane to be odorless, it does have a faint, disagreeable smell, similar to natural gas or petroleum. Butane is highly flammable and is an easily liquified gas. Its chemical formula is C₄H₁₀. Butane makes up a small part of the natural gas mixture, but it’s better known for its use in cigarette lighters, blowtorches, and portable stoves, and as an aerosol propellant, a refrigerant, and a heating fuel.
Are Gas and Natural Gas the Same?
What do gas and natural gas have in common? The majority of Americans will use both of them on a daily basis. They are also both made up of hydrocarbons, and since they’re made from fossil fuels, they are non-renewable resources. But gas and natural gas are not the same things. They may share the same name, but much like a nocturnal flying bat and the bat we use in baseball, they are quite different.
How Are Gas and Natural Gas Different?
We covered many of the ways that gas and natural gas are alike. Now, let’s take a look at a few of the characteristics that differentiate the two. Here are the top four distinctions:
- We use natural gas as a heating source, for cooking, and for electricity generation. Gas or gasoline (also known as petrol because it’s a product of petroleum and crude oil) is used mainly as engine fuel for vehicles.
- Natural gas produces nearly 25% less carbon dioxide than gasoline, making it a cleaner resource.
- In their natural states, gasoline is a liquid, while natural gas is actually a gas.
- Although they are both created with hydrocarbons, natural gas contains fewer atoms than gasoline.
Where Does Natural Gas Come From?
Naturally occurring gases result from layers upon layers of decomposing animal and plant matter found under sediment, land, and sea. When the buried organic matter becomes oxygen-deprived, it goes through a thermal breakdown of intense heat and pressure under the Earth’s surface. This process, which occurs over millions of years, converts organic matter into hydrocarbons and leaves it in the gaseous state of natural gas.
There are two categories of natural gas, which we base on the gas’s origin and location. The categories are labeled conventional and unconventional.
What Is the Difference Between Conventional and Unconventional Natural Gas?
Conventional natural gas deposits are mostly found with oil reservoir deposits and are relatively easy to access. We extract conventional natural gas through an original drilling method (called vertical well drilling) and traditional pumping techniques. We’ll get to more on this in just a bit.
Unconventional natural gas deposits are more difficult to access. Poor accessibility could be due to how far beneath the Earth’s surface they’re located. Generally speaking, we find unconventional natural gas deposits in rock formations that we classify as impenetrable. Unconventional natural gas is commonly extracted from coalbed methane, methane hydrates, shale gas, and tight gas sandstone.
How Do We Get Natural Gas?
After being wholly formed, natural gas deposits become trapped underground within rock formations. We can extract natural gas from there. The process is easiest if the surrounding sediments and rock formations are both highly permeable and porous.
What Is Permeability?
Something that can be passed through, generally by liquid and gas, is permeable. The easier it is to pass through, the higher permeability it has. Permeability in rock is measured by how the pore spaces are interconnected. Suppose natural gas has a lower density than its surrounding rocks. In that case, it will flow upwards through these pore spaces until it reaches tight rock formations, and there it sits. This is where we find many natural gas deposits today.
What Is Porosity?
When something is full of openings or tiny holes, we consider it to be porous. Rocks with high porosity have many small holes, or empty space, found within their rock grains. These voids allow for liquid and gas to be easily absorbed. Sandstone is an example of a rock with high porosity because it has a large amount of vacant space, or storage space, found within its grains.
How Do We Locate Natural Gas Deposits?
First things first, we can’t extract natural gas from any old rock formations. We first need to determine where to locate natural gas deposits. We can identify them by using seismic testing. Seismic waves are generated in areas where underground rock formations known to house natural gas deposits, such as coal beds and shale rock, are suspected to be.
Geophysicists interpret the results through acoustic receivers called geophones. After a natural gas deposit has been located and selected for development, a number of steps are taken.
First, the drilling company will meet with the landowner to discuss and negotiate their surface access rights. The crew will then determine which method of drilling will be necessary to reach the gas. And, they’ll drill an exploratory well to find out if there is a large enough natural gas deposit to justify extraction.
How Is Natural Gas Extracted?
There are three different techniques used for the extraction of natural gas. The method is chosen based on the area’s geology and how accessible the natural gas deposits are. The three modes of extraction include vertical drilling, horizontal drilling, and hydraulic fracturing, also known as fracking.
What Is Vertical Drilling?
Circling back to conventional natural gas, vertical drilling is typically only used when natural gas deposits are found directly below the Earth’s surface. Wells are drilled right into the porous rock formations that are holding these conventional natural gas deposits. True to its name, the drilling happens straight down, in a vertical direction.
Vertical drilling is the first method ever used to extract natural gas from the Earth’s surface. In fact, up until the 1980s, vertical drilling was the only method we had. We still use this method today when we are able to since it’s the easiest and most cost-effective method for extraction.
What Is Horizontal Drilling?
Not all natural gas deposits occur in easily accessible places. Cue the 1980s when horizontal drilling came into the picture. This invention allowed geologists to take drilling in another direction — literally. Previously inaccessible natural gas deposits are now extractable thanks to the technology of horizontal drilling. Here, a flexible drilling pipe and a steerable drill bit work together to navigate tight rock formations by bending a vertical well and then drilling at a horizontal angle through the natural gas deposit.
What Is Hydraulic Fracturing or Fracking?
Hydraulic fracturing, or fracking, is the method used throughout North America to unearth natural gas that was previously inaccessible due to impenetrable rock formations. The fracking process involves injecting a mixture of chemicals, sand, and water into a well at high pressures. These high pressures fracture rock formations that lay far down beneath the Earth’s surface, hence the name hydraulic fracturing.
The act of fracturing the rock formations causes a release of the trapped natural gas. As the gas is released, it travels upward toward the Earth’s surface where it enters the well. Continuing to rise, the natural gas then exits the head of the well into piping, where it’s transferred to nearby storage tanks.
What Are the Concerns About Fracking?
Although it may allow us access to natural gas deposits that we otherwise couldn’t reach, many people are concerned about the effect fracking has on the environment. Listed below are a few of the main reasons why.
- We must use large amounts of water for fracking, which is not so eco-friendly. It also makes it difficult and costly since the heavy water often needs to be transported to remote locations.
- The fossil fuel industry is not transparent about which chemicals they use in the mixture. This non-transparency leads to the concern of possible groundwater contamination.
- Fracking may be the cause of some earthquakes.
What Happens With Natural Gas After Extraction?
After the drilling is complete and the natural gas supply is flowing into the well, the drilling equipment is removed and replaced with a wellhead. Gathering pipelines then move the gas supply to the processing plant facilities.
How Is Natural Gas Made?
In the gas plants, natural gas is processed using a filtration system. Filtration removes unwanted gases and other impurities such as acid, hydrogen sulfide, mercury, nitrogen, sulfur dioxide, and water vapor. Certain gas plants will even remove the by-products, such as butane, ethane, pentane, and propane.
We can process natural gas into two different forms, compressed natural gas (CNG) and liquefied natural gas (LNG). Upon completion of processing, the natural gas is considered clean and ready for consumer distribution.
What Is Compressed Natural Gas (CNG)?
Compressed natural gas is primarily comprised of methane. The high amounts of pressure used to create CNG shrink the gas to under 1% of its original volume. When combined with air and ignited, CNG works as fuel.
CNG fuel has many benefits over traditional gasoline. It’s easier on engines, natural gas prices are significantly lower than gasoline prices, and it’s readily available in the United States. It’s also better for the environment than gasoline since CNG combustion produces fewer hydrocarbons, carbon monoxide, and nitrogen oxides.
Since natural gas is odorless and colorless, natural gas companies add odorants to CNG as a safety precaution. The odor is similar to the smell of rotten eggs. Gas companies add the foul smell to CNG to warn people of potential leaks. If a leak occurs outdoors, CNG is so light that it should simply dissipate. But a leak in an enclosed space could prove dangerous as it may cause a fire or explosion, and could lead to serious health problems, including suffocation.
Compressed natural gas can be easier to handle than liquefied natural gas. Adding to its benefits, CNG is less expensive to produce and has an unlimited hold time, which means it will never expire while in storage.
What Is Liquefied Natural Gas (LNG)?
Liquefied natural gas is still primarily comprised of methane, but it’s been processed into a liquid state. To achieve this, anything that can freeze, such as carbon dioxide, certain hydrocarbons, and water vapor, must be removed, and the gas must be cooled to negative 260 degrees Fahrenheit. This extreme temperature can make it difficult and dangerous to handle.
Once converted, LNG’s volume is around 600 times smaller than the original gas. This conversion makes LNG the ideal form of natural gas for storage, especially since it can easily convert back to its gaseous state as needed. Liquefied natural gas has many of the same benefits as CNG, plus it’s non-flammable and nonexplosive, making it significantly safer for both domestic and international transportation.
However, unlike CNG, LNG does not contain an odorant, which makes leak detection more difficult. LNG powered vehicles have electronic methane sensors installed to detect any leaks. LNG leaks are just as dangerous as CNG leaks. They have the potential to cause a fire or could lead to asphyxiation. Installing gas detectors can reduce the risk and alert consumers to any potential leaks.
How Is Natural Gas Distributed?
A vast network of gas pipelines is used to safely move natural gas supplies from extraction sites to the processing plants and then on to the final destination. From here, distribution or gas companies deliver natural gas to businesses and homes, or safely store it for use at a later date.
Does Natural Gas Rise or Fall?
It makes sense to assume that gases that are heavier than air will fall to the ground while gases that are lighter than air will rise. And, in a fundamental sense, this is, in fact, correct. If there is a significant natural gas leak in your home, methane, which is less dense than air, will rise to the ceiling. So, to answer the question above, natural gas rises.
However, the gas’s density does not vary enough from air’s density to keep it from mixing and diffusing relatively quickly. Because of this, if the leak is too small or too slow, it may not rise at all. After some time, even the gases that rise and accumulate on the ceiling will mix in with the air and distribute evenly throughout their space.
Natural Gas Safety
It’s essential to know how to protect yourself from potential natural gas leaks and what to do if you suspect one. If you use natural gas as a resource, consider purchasing and installing a gas leak detector.
While gas leaks are rare, they can happen at any time. The following are signs that there may be a leak in or around your property:
- A hissing sound or a roar
- Dead or discolored plants
- Frozen patches on the ground in warm areas
- The smell of rotten eggs or sulfur
If you suspect you may have a natural gas leak, refrain from doing anything that may cause a spark or ignition. Leave your property immediately to head for a safer area. Then, call your utility’s gas leak hotline to report the issue.
How Is Natural Gas Used? And Why?
The United States used around 22.8 trillion cubic feet of natural gas in 2009. Today, we still rely heavily on this non-renewable fossil fuel in a surprisingly significant number of ways. Why? Well, even though we know that fossil fuels like natural gas have a negative impact on the environment, we’ve also come to realize that they aren’t so easy to replace.
Alternative and renewable energy integration has come a long way. But resources like wind turbines and solar panels can’t currently produce enough energy to meet consumer demand. In order to be able to replace fossil fuels altogether, we need to develop a system that will match the affordability, accessibility, and efficiency of the fossil fuel based systems we’ve established over the past 200 years. Until then, we will continue to see natural gas as the main resource used to heat homes, provide electricity, and so much more.
For now, we classify how natural gas is used into five main categories:
- Electric power generation
- Industrial use
- Residential use
- Commercial use
- Vehicle fuel
What Are the 3 Biggest Uses of Natural Gas?
There are three primary uses for natural gas. Here’s a quick look at what they are.
1. Electric Power Plants
Over one-third of all-natural gas used in the United States is consumed for the generation of electricity. The U.S. Energy Information Administration estimates that utility-scale electric power plants generated approximately 4.13 trillion kilowatt-hours (kWh) of electricity throughout the U.S. in 2019. Of that, natural gas was the most used resource by far, providing over 38% of the electricity generation.
2. Industrial Use
Coming in just behind electric power plants, industrial use claims the number two spot. The industry also makes up approximately one-third of natural gas use throughout the United States. Natural gas is used as a heat source to keep factories warm and for incineration. But it’s also used in an incredible amount of manufacturing purposes.
We use natural gas as a heat source to manufacture essential products like:
- Food products
In manufacturing, natural gas is also used as an ingredient to make products like:
Additionally, we use natural gas to manufacture chemicals, including:
- Acetic acid
3. Residential Use
More than one-half of U.S. homes use natural gas as a resource. The majority of these residential consumers use it as a heating source for space heaters and water heaters. Natural gas is also commonly used for cooking, doing laundry, lighting fireplaces, and powering some light fixtures.
Where Do We Find Natural Gas?
A mere 10 countries contain nearly 80% of the world’s largest natural gas reserves. Saudi Arabia, United Arab Emirates, Venezuela, Nigeria, and Algeria round out the bottom of that list as numbers six through ten, respectively. Here are the top five:
Home to just over 19% of the world’s fossil fuel reserves, Russia boasts about one-fourth of the total gas reserves worldwide. Over half of the country’s natural gas reserves can be found in Siberia. Yamburg, Urengoy, and Medvezhye are three of the region’s significant reserves. Still, most of Russia’s gas reserves are located in the Nadym-Pur-Taz (NPT) region of upper Western Siberia.
Although the second biggest natural gas reserves in the world belong to Iran, the majority of them sit undeveloped. Over 60% of the country’s natural gas reserves are offshore. Iran’s largest gas field is South Pars. Other significant natural gas reserves in the country are North Pars, Kish, and Kangan.
Qatar sits in the number three spot as the world’s largest LNG supplier. The country’s natural gas reserves cover an area equal in size to Qatar itself. North Field, the country’s leading source of natural gas production, is the largest non-associated gas field globally.
Although Turkmenistan faces some difficulties developing its gas reserves, this Central Asian country is home to the world’s fourth-largest natural gas reserves. One of its oldest and largest gas fields is the Dauletabad Field in the Amu Darya basin. The South Yoloten area, which lies in the eastern region, also contains significant natural gas reserves.
5. United States of America
The majority of natural gas production in the U.S. is in Texas and around the Gulf of Mexico. Key regions that contain natural gas are located in the Marcellus Shale rock formation in the eastern United States and the Barnett Shale rock formation in Texas. Shale formations have been discovered in over 30 states. The U.S. is currently the largest consumer and the largest producer of natural gas in the world.
How Is Natural Gas Measured?
In general, we measure natural gas in cubic feet (cf). However, when calculating how much energy is generated by natural gas, the measurement unit is British thermal units (BTU). Increasing one pound of water’s temperature by one degree Fahrenheit is equivalent to one BTU. When reading your gas bill, you will likely see your natural gas consumption listed in British thermal units. One cubic foot is equal to 1,027 British thermal units.
How Much Natural Gas Is Left?
Global energy demand is steadily increasing while fossil fuels, including natural gas, remain the leading energy resource. Unfortunately, these resources have been rapidly depleting due to the severe increase in population and demand.
We are so dangerously close to running out of natural gas that a change in regulatory measures and an effort to practice energy efficiency is critical. If we don’t make a change, we will deplete our supply of natural gas before today’s children grow old.
The U.S. Energy Information Administration estimated that there were only around 7,177 trillion cubic feet (Tcf) of natural gas reserves remaining as of January 1, 2019.
Suppose the current rate of natural gas production remains the same. In that case, we estimate that there are only 40 to 52 years worth of natural gas reserves remaining. Since there is even less oil remaining than gas, we could be forced to increase our natural gas use, which would put us closer to the short end of that time span.
Is Natural Gas Considered Clean Energy?
Although natural gas is considered the cleanest burning fossil fuel—and is considered by some to be a form of clean energy—many now express that while it might be “cleaner,” natural gas is not actually a clean energy resource. When burned, natural gas releases carbon emissions into the Earth’s atmosphere, which scientists link to environmental complications. It is known as being the cause of air pollutants, chronic health problems, climate change, global warming, habitat destruction, and natural disasters.
How Can I Help With Natural Gas Conservation?
As an alternative resource, renewable natural gas (RNG), which is also known as biomethane, is a fuel produced from landfill waste, livestock, and other organic materials through anaerobic digestion. It is not a fossil fuel, but RNG is identical in chemical make-up to conventional natural gas. This similarity allows it to use the same system for distribution as natural gas.
RNG is just one of the many alternative energy options available today. There is no more time to waste. Reach out to your energy provider to ask about the green energy products they have to offer. Get started on your path to energy conservation today.
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