LPG is a versatile, readily available energy source that can be used to power transportation vehicles. It comes with lower levels of CO₂ emissions than fossil fuels and can combat climate change. So we had to ask: What is the carbon footprint of LPG?

LPG has a lower carbon footprint than gasoline and diesel fuel. One gallon of LPG emits 12.52 pounds (5,680 grams) of CO₂ when combusted, and driving one mile on average emits 319 grams of CO₂. It combats climate change and has various environmental benefits, but its source must also be considered.

Keep reading to learn about the overall carbon footprint of LPG, its carbon footprint throughout its life-cycle, and how environmentally friendly it is.

Here’s What the Carbon Footprint of LPG Is

The carbon footprint is one of the ways we measure the effects of human-induced global climate change. It primarily focuses on the GHG emissions associated with consumption, but also includes other emissions such as methane (CH₄), nitrous oxide, and chlorofluorocarbons.

“Carbon footprint: the amount of greenhouse gases and specifically carbon dioxide emitted by something (such as a person’s activities or a product’s manufacture and transport) during a given period”

Merriam Webster

Basically, it is the amount of carbon emitted by an activity or an organization. This includes GHG emissions from fuel that we burn directly (e.g., heating a home, driving a car) and GHG emissions from manufacturing the products that we use (e.g., power plants, factories, and landfills).

LPG, also known as liquified petroleum gas, refers to 2 natural gas liquids: propane and butane. Or a mixture of the two. In total, there are around 1,000 applications of LPG, making it extremely versatile. It can be used for cooking and heating, to generate power, and as an alternative transportation fuel. 

“LPG (liquefied petroleum gas): a type of fuel used for heat, cooking, and in some vehicles”

Cambridge Dictionary

As a transportation fuel, LPG is referred to as autogas. It is the #1 unblended alternative fuel in the world, with more than 25 countries promoting its use. Autogas powers roughly 27 million vehicles globally, and global consumption has increased by 40% in the past decade. The two components of autogas are propane and butane. 

Propane and butane are by-products of natural gas (NG) processing and crude oil refining. Although they are chemically very similar, minute differences make propane and butane suited for different applications. Liquid components recovered during NG processing include ethane, methane, propane, and butane, and heavy hydrocarbons. Liquid components recovered during oil refining include propane, butane, and other gases. 

Propane (C₃H₈) is a gaseous, alternative, cleaner-burning fuel used in light-, medium-, and heavy-duty propane-specific vehicles. 

“Propane: a heavy flammable gaseous alkane C₃H₈ found in crude petroleum and natural gas and used especially as fuel and in chemical synthesis”

Merriam-Webster Dictionary

Propane can only be used in propane-specific vehicles (shuttles, police vehicles, school buses) in the form of HD-5, which consists of at least 90% propane and no more than 5% propylene and 5% other gases (butane and butylene). 

Butane (C₄H₁₀) is a gaseous, alternative, cleaner-burning fuel used in LPG-specific vehicles.

“Butane: either of two isomeric flammable gaseous alkanes C₄H₁₀ obtained usually from petroleum or natural gas and used as fuels”

Merriam-Webster Dictionary

Butane is usually blended into gasoline or LPG or is sold commercially as home heating fuel, cigarette lighter fluid, refrigerant gas, or a propellant. Butane has a high octane rating, but it also has a high vapor pressure. This means it readily evaporates at warmer temperatures and is, therefore, better suited for colder temperatures.

Unlike gasoline and diesel fuel which emit 19.59 and 22.44 pounds (lb) of carbon dioxide (CO₂), respectively, per gallon upon combustion, propane emits only 12.61 lb and butane emits only 14.7 lb per gallon. As a whole, LPG emits only 12.52 lb of CO₂ per gallon. 

Oil (including gasoline and diesel fuel) is the world’s primary fuel source for transportation. But since the turn of the century, there has been a push towards cleaner-burning transportation fuels with fewer negative effects on the environment. This is one major reason the LPG market is expected to increase from $130.1 billion (B) in 2020 to $243.4B by 2030.

To understand the total carbon footprint of LPG, we must assess its life-cycle and each stage’s carbon footprint. This life-cycle assessment (LCA) is a method to evaluate the environmental impacts of products and materials. Over the years, companies have strategically used LCA to research and create more sustainable products. So, let’s have a look at the LCA of LPG!

The total carbon footprint of LPG would equal the carbon footprint from building + the carbon footprint from extracting and refining + the carbon footprint from transportation + the carbon footprint from building back.  

What Is the Carbon Footprint of Building LPG Refineries

LPG is a by-product of natural gas (NG) processing and crude oil refining. Oil wells extract crude oil and NG, which is then transported to petroleum refineries or NG power plants. Petroleum refineries and NG power plants consist of machinery such as boilers, cooling towers, blowdown systems, compressor engines, and heaters, all of which must be manufactured and therefore also have a carbon footprint. Likewise, the construction equipment needed to physically construct the buildings emits CO₂.

What Is the Carbon Footprint of Extracting LPG

In order to extract LPG you first need to extract the oil and NG from which it is derived. Oil and NG are often found within the same reservoir, so they are often extracted in the same manner. Drilling or fracking exposes oil and NG reservoirs for extraction.

Extracting oil and NG involves seven main steps:

1. Preparing the rig site
2. Drilling
3. Cementing and testing
4. Well completion
5. Fracking
6. Production and fracking fluid recycling
7. Well abandonment and land restoration

LPG is then collected as a byproduct of oil refinement and NG processing.

Oil refinement occurs via the following steps:

• Distilling: Crude oil is heated until it becomes a vapor. The vapor is lifted upwards in a distilling column and collects at different levels in trays, separating the liquids. Lighter products (butane) rise to the top of the column whereas gasoline, naphtha, kerosene, diesel, and heavy gas oil collect in trays going from top to bottom in the column.

• Cracking: Because there is a demand for lighter distilled products like gasoline, refineries convert heavy liquids into lighter liquids via cracking. Cracking breaks up long hydrocarbon chains into smaller ones, converting heavy oil into gasoline. Cat cracking, catalyst-driven cracking, is the most common form of cracking. 

• Reforming: Refineries again use a catalyst to increase the quality and volume of gasoline. Reforming increases the octane number by rearranging the naphtha hydrocarbons to create gas molecules. A high octane number is more beneficial because it can withstand more compression before detonating. And the higher the octane number, the more stable the fuel. 

• Treating: Crude oil contains pollutants including sulfur, nitrogen, and heavy metals that must be removed. The treating process removes these pollutants either by binding them to hydrogen, absorbing them in columns, or adding acid to them.  

• Blending: Finished petroleum products are a blend of various streams of hydrocarbons that are then mixed into motor fuels. Refineries can also mix additives such as octane enhancers, metal deactivators, anti-oxidants, anti-knock agents, rust inhibitors, or detergents. 

And processing NG typically involves four main steps:

1. Oil and condensate removal
2. Water removal
3. Separation of natural gas liquids
4. Sulfur and CO₂ removal

These two processes produce LPG that can then be gathered and transported for commercial use.

What Is the Carbon Footprint of Transportation of LPG

Crude oil and NG are transported from extraction wells to oil refineries and NG power plants via barges, tankers, pipelines, trucks, and railroads. After refinement and processing removes the LPG, it is stored as a liquid until it is needed. When it is needed, it is transported to a retail plant that a local LPG supplier draws from for consumer consumption. But if the LPG is not being consumed locally, it must be transported. And sometimes over very long distances. 

The top 5 LPG-consuming countries (thousand tons) in 2019 were:

1. Turkey – 3,354 
2. Russia – 3,250
3. Korea – 3,035
4. Poland – 1,925
5. Ukraine – 1,800

The share of LPG in total fuel consumption ranges from 0.03% in the United States to over 20% in Ukraine.  

Calculating the carbon footprint of LPG transportation involves knowing where the LPG is produced, where it is being consumed, and the distance between the two. For example, transporting LPG from the United States to Turkey is an approximately 6,341 miles (10,205 kilometers) transportation distance. Likewise, the transportation distance between the United States and South Korea is approximately 6,690 miles (10,766 kilometers) transportation distance. 

The carbon footprint of transportation for these instances would be high because of the long transportation distance multiple modes of transportation required. 

On the other hand, if LPG is produced in Turkey and is also being consumed in Turkey, the transportation distance is much shorter and would require fewer modes of transportation, leading to a lower carbon footprint for this stage. 

Essentially, the longer the transportation distance, the higher the carbon footprint. And the higher the carbon footprint for this, the worse effect it has on the environment. 

What Is the Carbon Footprint of Building Back LPG Refineries

LPG is a by-product of natural gas (NG) processing and crude oil refining. Oil wells can produce for anywhere from 20-40 years, and NG plants have an average age of 22 years in the US. When an oil or NG well is done producing, it is plugged to stop the flow of methane to the surface. 

However, over 3 million abandoned oil and NG wells are unplugged in the US alone, and these wells leak millions of metric tons of methane into our atmosphere every year. Simply plugging these wells could reduce methane emissions by 99%, which would help mitigate global warming. 

In some instances, the area surrounding the well can be restored. In offshore drilling, the program “Rigs-to-Reefs” topples old oil wells and leaves them on the seafloor, establishing an artificial reef that attracts barnacles, coral, clams, sponges, and other marine life. This method has virtually no carbon footprint because the existing well is not demolished.

What Role Does LPG Play in Combating Climate Change

An LPG-powered vehicle emits approximately 21% less CO₂ compared to a gasoline-powered vehicle. This reduction in CO₂ emissions can help combat climate change.

“Climate Change: changes in the world’s weather, in particular the fact that it is believed to be getting warmer as a result of human activity increasing the level of carbon dioxide in the atmosphere:”

Cambridge Dictionary

Climate change is arguably the most severe, long-term, global impact of fossil fuel combustion. Every year, approximately 36 billion tons (bt) of CO₂ are emitted from burning fossil fuels. The carbon found in fossil fuels reacts with oxygen in the air to produce CO₂ which warms the earth by acting as a heating blanket.

Reduced CO₂ emissions from propane combat climate change in the following ways:

• Increasing temperatures: Earth’s atmosphere has warmed 1.5 degrees Celsius (C) since 1880. This may not seem like a lot, but these degrees create regional and seasonal temperature extremes, reduce sea ice, intensify rainfall and drought severity, and change habitat ranges for plants and animals.

• Rising sea levels: Global sea levels have increased approximately 8-9 inches since 1880, displacing people living along coastlines and destroying coastal habitats. Roads, bridges, subways, water supplies, oil and gas wells, power plants, sewage treatment plants, and landfills remain at risk if sea level rise goes unchecked. 

• Melting of sea ice: Since 1979 arctic sea ice has declined by 30%. Sea ice plays a major role in regulating the earth’s climate by reflecting sunlight into space and providing habitat for animal species. If all of the glaciers on Earth melted, sea levels would rise by approximately 70 feet, effectively flooding out every coastal city on the planet. 

• Changing precipitation patterns: Extreme weather events (e.g., hurricanes, floods, droughts) are becoming more common and more intense. Storm-affected areas will experience increased precipitation and flooding whereas areas located further from storm tracks will experience decreased precipitation and droughts.

• Ocean acidification: The ocean absorbs 30% of the CO₂ released into the atmosphere, which decreases the pH (increases the acidity) of the ocean. In the past 200 years, the pH of oceans has decreased by 0.1 pH units, which translates to a 30% increase in acidity. Aquatic life unable to adjust to this rapid acidification will die off. A prime example of this is coral bleaching, where coral expel the algae (zooxanthellae) living in their tissues as a result of changes in temperature, light, or nutrients. 

Climate change results in global warming, when CO₂ and other air pollutants absorb sunlight and solar radiation in the atmosphere, thereby trapping the heat and acting as an insulator for the planet. Since the Industrial Revolution, Earth’s temperature has risen a little more than 1 degree Celsius (C), or 2 degrees Fahrenheit (F). Between 1880-1980 the global temperature rose by 0.07C every 10 years. This rate has more than doubled since 1981, with a current global annual temperature rise of 0.18C, or 0.32F, for every 10 years. 

Experts claim that to avoid a future plagued by rising sea levels, acidified oceans, loss of biodiversity, more frequent and severe weather events, and other environmental disasters brought on by the hotter temperatures, we must limit global warming to 1.5C by 2040. 

The more we reduce CO₂ emissions, the more we slow the rate of temperature rise, sea-level rise, ice melting, and ocean acidification. When these rates are slowed, the earth’s biodiversity does not have to struggle to adapt to temperature and pH changes. People will not be displaced due to the flooding of coastal areas. And icebergs will continue to provide climate regulation. 

How Environmentally Friendly Is LPG

LPG is considered a clean-burning fuel because the GHG emissions from LPG combustion are much lower than that of gasoline and diesel fuel. 

“Environmentally friendly: (of products) not harming the environment.”

Cambridge Dictionary

When discussing the issue of climate change, both the environmental benefits and drawbacks of LPG must be taken into consideration.

What Are Environmental Benefits of LPG

The environmental benefits of LPG include:

1. Mitigates climate change: The carbon footprint of LPG is 20% lower than conventional heating oil, and LPG emits 35% less CO₂ than coal and 12% less CO₂ than oil.

2. Improves air quality: Using LPG instead of gasoline reduces CO₂ emissions by 21% and particulate nitrogen by 81%. Using LPG instead of diesel fuel reduces nitrogen oxide emissions by 74% and particulate matter by 81%. These pollutants can cause ground-level ozone formation, acid rain, cancer, and reproductive/birth defects. 

3. Eliminates oil spills: In the event of an oil spill, LPG quickly evaporates into the atmosphere. This means it will not leach into and contaminate the surrounding soil or water source.

4. Eliminates fugitive emission impacts: Because it is not a GHG, LPG will not negatively harm the environment if it is released into the atmosphere prior to combustion. On the other hand, NG is composed mostly of CH₄, which has a global warming potential of 25 times that of CO₂. If it is released into the atmosphere prior to combustion, NG will only accelerate the global warming process. 

5. Mitigates deforestation: Deforestation occurs at roughly 10 million hectares (~ 25 million acres) per year, and the world has lost more than 1/3 of its forest since the last ice age, about 2.6 million years ago. If 240 million households converted to LPG, this could save 2.37 million hectares of forest, which is equivalent to 46% of annual net global deforestation. Trees combat climate change, purify the air, provide housing for millions of plant and animal species, protect against floods and water pollution, and improve mental health. Protecting forest habitats increases carbon sequestration and decreases the effects of global climate change. 

What Are Environmental Drawbacks of LPG

LPG is derived from fossil fuels, meaning it still comes with some environmental drawbacks. Sourcing LPG from oil and NG produces CO₂ that contributes to climate change. Oil combustion releases 12 and NG releases 7.5 billion tons of CO₂ into our atmosphere every year. Although the CO₂ emissions from the combustion of NG are about 50%-60% less than those from coal and oil, the primary component of NG is CH₄, a gas 34 times stronger at trapping heat than CO₂ over 100 years. This means that a little CH₄ can go a long way when contributing to global warming.

A way to avoid this environmental drawback is to acquire LPG from low-carbon sources including solar power and wind power. These emit between 38-48 (solar) and 11-12 (wind) grams of CO₂ equivalent per kWh of electricity produced, compared to 970 grams for oil and 490 grams for NG. 

The process of LPG extraction from oil and NG also comes with the following additional environmental drawbacks:

• Drilling: This can disturb vegetation and soil and may require clearing and leveling the area around a well pad. Drilling also produces air pollution and may contaminate water sources via erosion, fracking fluids, equipment runoff, and sedimentation. 

• Landscape alterations: Drilling for NG causes surface distribution from drill pads, roads, and pipelines that alter the landscape. Fragmentation of wildlife habitat and migration patterns have also been documented. 

• Water pollution: Land clearing may cause dirt, minerals, and other pollutants to erode into nearby waterways. Drinking water may become contaminated with hazardous chemicals via drilling, fracturing, processing, and refining the gas, and wastewater disposal. 

Final Thoughts

LPG has a lower carbon footprint across its building, extraction, transportation, and building back stages when compared to gasoline and diesel fuel. It emits fewer amounts of GHG emissions upon combustion, burns cleaner than traditional fossil fuels, and can help mitigate deforestation. Because LPG is derived from oil and NG, the environmental drawbacks of oil and NG apply to LPG as well and therefore must be taken into account.

Stay impactful,

Sources

• Britannica: Carbon Footprint
• United States Environmental Protection Agency: System of Registries
• World LPG Association: What is LPG?
• International Energy Agency – Advanced Motor Fuels: Liquefied petroleum gas, LPG
• US Department of Energy –
• Alternative Fuels Data Center: Propane Fuel Basics
• Elgas: LPG vs Propane – Is Propane the Same as LPG
• Britannica: Butane
• US Environmental Protection Agency: Greenhouse Gas
• Emissions from a Typical Passenger Vehicle
• US Energy Information Administration: Carbon Dioxide Emissions Coefficients by Fuel
• US Environmental Protection Agency: Emission Factors for Greenhouse Gas Inventories
• World LPG Association: Where is LPG Used?
• World LPG Association: Autogas
• McKinsey&Company: Butane
• Impactful Ninja: What is the Carbon Footprint of Oil Energy?
• Impactful Ninja: What is the Carbon Footprint of Gasoline?
• Impactful Ninja: What is the Carbon Footprint of Diesel Fuel?
• Environmental and Energy Study Institute: Fossil Fuels
• GlobeNewswire: Liquefied Petroleum Gas (LPG) Market To Reach $243.4 Billion by 2030
• Science Direct: Life-cycle assessment (LCA) 
• MIT SMR: Strategic Sustainability Uses of Life-Cycle Analysis
• American Petroleum Institute: Refinery Processes
• Propane: How is Propane Distributed?
• US Environmental Protection Agency: Petroleum Refining
• Coloradans for Responsible Energy Development: The seven steps of oil and natural gas extraction
• US Energy Information Administration: Gasoline Explained – Octane in Depth
• NaturalGas.org: Processing natural gas
• Library of Congress: Modes of Transportation – Oil and Gas Industry – A Research Guide
• World LPG Association: Portable
• World LPG Association – Autogas.net: Autogas Incentive Policies
• World LPG Association – Autogas.net: The Autogas Market
• Distancefromto: Distance from Turkey to United States
• Distancefromto: Distance from South Korea to United States
• Coloradans for Responsible Energy Development: How long does fracking last?
• US Energy Information Administration: Natural gas generators make up the largest share of overall U.S. generation capacity
• Forbes: Plugging Abandoned Oil Wells Is One ‘Green New Deal’ Aspect Loved By Both Republicans And Democrats
• Bureau of Safety and Environmental Enforcement: Rigs-to-Reefs
• US Department of Energy – Alternative Fuels Data Center: Propane Vehicle Emissions
• World Nuclear Association: Carbon Emissions from Electricity
• The National Wildlife Federation: Climate Change
• National Oceanic and Atmospheric Administration: Climate Change – Global Temperature
• National Oceanic and Atmospheric Administration: Climate Change – Global Sea Level
• United States Geological Survey: How would sea level change if all glaciers melted?
• National Aeronautics and Space Administration, U.S.A.: How does climate change affect precipitation?
• National Oceanic and Atmospheric Administration: Ocean Acidification
• National Ocean Service: What is coral bleaching?
• United Nations Framework Convention on Climate Change: The Paris Agreement
• National Resources Defense Council: Global Warming 101
• World LPG Association: Clean
• Canadian Propane Association: Environmental Benefits
• Union of Concerned Scientists: Environmental Impacts of Natural Gas
• Our World in Data: Deforestation and Forest Loss
• Food and Agricultural Organization of the United States: State of the World’s Forests 2020
• World LPG Association: Deforestation
• Woodland Trust: Why do we need trees?
• One Green Planet: How Saving Wildlife Benefits Humans – In Ways We Really Need