Natural Gas and It’s Dual Forms: CNG Versus LNG

George Stark
Director, External Affairs
Cabot Oil & Gas


George Stark does a quick lesson on natural gas and the two ways it is delivered for use in transportation, not to mention other activities of daily life.

While you may generally know what natural gas is, you may not know how it is produced, how it is used, or how it is transported unless you are an expert working in the industry.

Natural gas is extremely important to our everyday lives because it provides a clean and efficient alternative resource to the traditional means that power our nation. Natural gas can be used in two different forms – CNG and LNG.

Compressed Natural Gas (CNG)

What is CNG? CNG, or Compressed Natural Gas, is a clear, odorless and non-corrosive form of natural gas that is created using high amounts of pressure and comprised primarily of methane. The substance is pressurized at 3,600 pounds per square inch to become less than 1% of its original volume.  Once the compressed gas is combined with air and ignited, the energy needed for fuel is created.

What is CNG used for? CNG, in its gaseous state, is primarily used as a source of fuel. Although CNG is mainly used to fuel trucks and busses, there are some cars that are powered by it, as well.

What are the benefits of CNG? The benefits of using CNG as fuel far outweighs those of using traditional gasoline. CNG is significantly cheaper than gasoline. In fact, it is about a third of the price to fill up the average tank. This could partially be due to its abundance within the U.S., making us less dependent on foreign fuel sources. Using CNG is better for your engine and the environment. Because CNG is a cleaner burning fuel, the vehicle engine requires less maintenance for a more efficient engine. While burning, the CNG also gives off fewer emissions, which leaves the air less polluted than gasoline would.

Liquified Natural Gas (LNG)

What is LNG? Liquified Natural Gas, commonly referred to as LNG, is essentially just natural gas in a liquid state. The gas is cooled to an extreme temperature to become a clear and non-toxic liquid.  To convert the substance to LNG, materials that can freeze, such as water, carbon dioxide, and heavier hydrocarbons are removed so that it can be cooled to –260 degrees Fahrenheit into a liquid.  In this form, LNG becomes about 600 times smaller than its original volume, which makes it ideal for transporting and storing.

What is LNG used for? Since LNG is primarily used for transportation purposes, it can be easily exported internationally. For example, Cabot produces natural gas in Susquehanna County, Pennsylvania and then converts it to LNG. Once in the liquid state, we ship it to Japan, which is one of our company’s biggest consumers of the Susquehanna natural gas.  The ships are equipped with carriers that are specifically designed for LNG transport. Although there are different sizes of carriers, they all maintain the appropriate pressure and temperature needed to keep the LNG viable on its way overseas.  When it is ready to be used from storage, it can be used for fuel or returned to its gaseous state for residential and industrial purposes.

What are the benefits of LNG? Liquid natural gas is a more cost-effective and clean burning fuel source than other alternatives, such as coal or oil. Its abundance in the U.S. also ensures that energy needs can be met, locally and across the globe.  Since LNG is a liquid, it is not flammable or explosive in this state, which makes it significantly safer than some other resources.

Reposted, with permission, from Well Said Cabot.

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2 thoughts on “Natural Gas and It’s Dual Forms: CNG Versus LNG

  1. Right now, in gasoline-starved Venezuela, motorists are carrying around cannisters of propane in their trunks after having their auto mechanics adapt their engines to burn propane rather than gasoline.
    The September 4, 2019 issue of ‘Asian Scientist’ has an article (“Flexible Polymers For Natural Gas Storage”) describing the breakthrough discovery of an adsorbent (‘d’, not ‘b’) material that achieves the ‘Holy Grail’ status of effective storage of abundant natgas at the sub 500 psi threshold.

    Connection between the 2 above statements?

    This new adsorbent polymer (COP-150) – costing a buck per pound to easily produce – can be emplaced in form-fitting containers and store 17 to 30 Gallon of Gasoline Equivalent (GGE) amounts of natty for virtually any car/truck currently on the road.
    An Ohio-based company is presently a world leader in producing these ‘tanks’ – mainly comprised of carbon.

    Kits to convert gasoline engines to run on CNG are available online right now and any competent mechanic can install the hardware in a short amount of time.

    With all the monumental ripple effects of these emerging technologies, a particulary impactful one will arise as virtually all of the 50 million plus US residences currently supplied with natgas will be able to fuel up their vehicles right in their driveways.

  2. That sounds like a great breakthrough. Storage is one of the main limiting factors to converting Semi trucks to natural gas. To give them the same driving range of big diesel tanks. What we need is real power Ideas not ” They are building new battery technology that will solve all of our problems” They have made batteries smaller and lighter but they have not improved on the strength and durability of the lead acid battery.

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