What is the Difference Between Natural Gas and Propane?

Natural gas and propane are eco-friendly fuels with several advantages. They are commonly used for heating purposes, fueling vehicles, and cooking, among other things.

There is often a misconception that natural gas and propane are the same.

However, there are several differences between the two gases, such as how they are formed, captured, stored and used. 

What is Natural Gas?

Natural gas is a gaseous mixture of hydrocarbons, including propane, butane, and ethane that is predominantly made up of methane (CH4).

Methane (Ch4) is a compound that has one carbon atom and four hydrogen atoms.

Natural gas is lighter than air and is invisible, odorless and highly flammable.

What is Propane?

Propane is a gaseous mixture also known as liquefied petroleum gas (LPG).

Propane is a three-carbon alkane gas (C3H8) that is a by-product, meaning it is never created for its own sake.

It is a non-toxic, colorless, and odorless gas. It is usually stored under pressure as a liquid.

How is Natural Gas Formed, Captured and Stored?

Natural gas is a fossil energy source that forms deep beneath the earth’s surface over the course of hundreds of millions of years. It is formed when decomposing plants and animals are under pressure from rocks and become subject to intense heat.

The combination of pressure, heat, and time allows some of the carbon and hydrogen-rich material to turn into natural gas, coal or oil (petroleum).

Natural gas is captured through industrial extraction and drilling activities. The extraction of natural gas first began in New York State in 1825.

Large drills are used to tap into underground reservoirs by drilling vertically from the Earth’s surface. Pipelines are then established to transport the natural gas to the end-user.

In the United States and a few other countries, natural gas is also captured through hydraulic fracturing or fracking. This is the process of injecting highly specialized fluid into the cracks of rocks and rock formations to increase the rate at which natural gas can be captured.

Natural gas is stored underground in depleted oil and gas fields, aquifer reservoirs or salt caverns. Once natural gas has been liquified, then it can be stored above ground in tanks. Liquified natural gas has been cooled down to liquid form for safe transportation and storage.

How is Propane Formed, Captured and Stored?

Propane is a by-product of natural gas processing and petroleum refining. Propane was first discovered by a French chemist named Marcellin Berthelot in 1857 and was commercially available in the US by 1911.

Propane is captured during natural gas processing and oil refinement. It is not made from natural gas and oil, rather it is extracted from it.

Propane is separated from unprocessed natural gas using refrigeration and extracted from oil using a distillation tower. It is then pressurized and stored as a liquid in cylinders and tanks.

Propane is not transported via pipelines, instead, it is stored in tanks.

How Natural Gas and Propane are Used

Natural gas and propane are commonly used as fuels for electricity, heating, cooking and vehicles. Natural gas accounts for nearly 30% of the energy used in the United States, whereas propane accounts for only 2% of the energy used in the United States.

The comparison between natural gas and propane is most common in applications for vehicles and residential fuel supply for heating or cooking.

Common uses of Natural Gas and Propane Include:

  • Space and water heating
  • Electricity
  • Cooking
  • Drying clothes
  • Fuel for engine applications (e.g. forklift, farm engines, fleet vehicles, buses)
  • Vehicles
  • Refrigeration and cooling equipment
  • Outdoor Lighting
  • Barbeques and portable stoves
  • Manufacturing

Propane is commonly used in remote areas or areas outside major metropolitan centers because it is portable and reliable. In some cases, it is the only option available to residents. Natural gas requires a hook-up or pipeline for usage and is not suitable for off-the-grid areas.

Advantages and Disadvantages of Natural Gas and Propane

Natural gas and propane have several advantages, and disadvantages related to the environment, usage and storage. 

Natural Gas Advantages

  • It is clean-burning, producing less harmful emissions than other fossil fuels (coal and oil)
  • It does not produce waste products, such as coal ash
  • It can be easily transported through pipelines, directly to industry and residential properties
  • It does not require a storage tank

Propane Advantages

  • Over 95% of the propane used in the USA is produced in North America
  • It has no toxicity to the environment
  • Produces 30%-90% less carbon monoxide than typical automotive gasoline
  • Propane appliances are more durable than electric appliances

Natural Gas Disadvantages

  • It is a fossil fuel and non-renewable resource
  • It is a greenhouse gas when released into the environment
  • Natural gas infrastructure is expensive, as pipelines cost a lot of money to establish

Propane Disadvantages

  • It is a fossil fuel that is a by-product of natural gas and petroleum
  • Propane requires a storage tank to be installed and maintained on your property
  • Propane does not produce as much heat as the oil 

How are Natural Gas and Propane Different?

Natural gas and propane are attractive, as they are both abundant and reliable energy sources. If your home uses natural gas or propane for energy, you are not vulnerable to outages related to weather or unexpected events.

One of the major differences between natural gas and propane is how they are stored.

Natural Gas:

  1. It remains in its gaseous state and is delivered through a pipeline. Meaning that once the connection (i.e. pipeline) is established, you will have an endless supply.
  2. Dissipates more quickly than propane when released into the atmosphere. Some argue that because of this, it is safer than propane, which takes longer to dissipate into the air.
  3. Delivered through a pipeline directly to your home and releases 1030 BTUs per cubic foot, whereas propane requires a tank that needs to be refiled and releases 2,516 BTUs per cubic foot.

Propane:

  1. Is compressed into a liquid form and can be sold in portable canisters or storage tanks. It requires scheduled delivery for the tank to be refiled.
  2. Potentially hazardous if inhaled or if it is released in a confined space. Propane acts as a simple asphyxiate as it displaces oxygen.
  3. More than twice as efficient and only needs half as much to achieve the same output as natural gas. For example, it is estimated that propane heats water nearly 40% faster than electricity.

The price of natural gas and propane fluctuates regularly. However, more recently the price of natural gas has been on the rise. With that said, natural gas is often still cheaper than propane in most US states.

Environmental Impact of Natural Gas and Propane

Natural gas and propane are eco-friendly fuels despite being fossil fuels. Only natural gas is considered a greenhouse gas.

Environmental Impact of Natural Gas:

  1. Natural gas has a higher toxicity than propane as propane is not toxic nor damaging to the environment. That means that if propane were to leak into the ground, it would not contaminate the water or soil. The same cannot be said for natural gas.
  2. Natural gas is considered an eco-friendly fuel because it burns cleaner and leaves a smaller carbon footprint. Natural gas emits roughly 50% to 60% less carbon dioxide (CO2) than oil or coal. However, it is mostly made up of methane, which is a greenhouse gas that is about 84 times more potent than carbon dioxide.
  3. A majority of the environmental impact occurs during drilling and laying pipelines to transport the natural gas (e.g. air pollution, wildlife disruption, and contamination of water sources).
  4. Pollutants from natural gas often get into the atmosphere by mistake, after leaks in pipelines or accidents during drilling.

Environmental Impact of Propane:

  1. Propane is an approved clean fuel and was listed on the 1990 Clean Air Act. It is noted as one of the cleanest burning fossil fuels available and produces half the carbon dioxide and other emissions of gasoline.
  2. Using propane, as an alternative to gasoline or fuel oil, is said to reduce greenhouse gas carbon dioxide emissions and air pollutants (e.g. carbon monoxide and nitrogen oxide).
  3. Propane is unique in that is an environmentally friendly fuel both before and after combustion.

In Summary What is the Difference Between Natural Gas and Propane

Natural gas and propane are both considered environmentally friendly fuels with ample advantages over conventional fuels (e.g. oil or coal).

The major difference between the two is how they are stored, their efficiency, and their impact on the environment.

Propane has a clear advantage as it will not contribute to pollution in its unused state, while natural gas will.

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