This article was originally published in The Link, Q2, 2022. Visit ngconnect.southerngas.org/lng to access this digital document to view associated graphs, sources and all links.
What is LNG?
The term liquefied natural gas (LNG) is used to describe a variety of liquefied gas mixtures composed primarily of methane and small quantities of heavier hydrocarbons and nitrogen. LNG is formed when natural gas is cooled to approximately -260°F at atmospheric pressure. Under these conditions, the natural gas condenses into a liquid, occupying approximately 1/600 of its volume as a gas. LNG has a density of about 26.5 lb/ft3 and vaporizes readily on contact with any solid or liquid surface at a higher temperature. Once in a liquid state, LNG is much easier to transport.
LNG storage and peak shaving is a very economical way for Local Distribution Companies (LDCs) to maintain and control the costs of natural gas supplies to their customers by storing and regasifying when needed. Given the volatility of spot pricing of natural gas during times of peak loads on transmission lines and the need for peaking demand loads for LDCs, LNG storage and peak shaving allow an LDC to liquefy, or purchase LNG, and store during periods of low demand and lower cost of gas; then regasify at times of peak demand and higher cost of gas, potentially generating significant savings.
According to the Pipeline and Hazardous Materials Safety Administration, PHMSA, “LNG storage enables a reliable supply of natural gas in areas where pipeline capacity limitations and weather conditions may cause supply and demand discrepancies, notably in the northeastern United States, thus increasing efficiency and reliability in supplying needed energy resources. LNG peak-shaving plants typically have significantly less LNG storage capacity than import and export terminals but are strategically located in the pipeline system.” There were 165 active LNG facilities in the US in 2020 with over 100 of the facilities used for peak shaving.
MYTH: LNG is not environmentally responsible
Natural gas is the cleanest-burning fuel available because it generates 75% fewer nitrogen oxide (NOx) emissions and 30% less carbon dioxide (CO2) emissions compared to other fossil fuels. It also has no environmentally damaging sulfur dioxide (SO2) emissions.
The combustion of natural gas does not emit soot, dust or fumes. Unlike crude oil and crude-derived liquid fuels, if LNG spills, it does not cause any residual impact on the environment. This is because it evaporates immediately and dissipates quickly into the atmosphere; it does not require any remediation of soil, groundwater, or surface waters.
LNG helps displace higher-carbon fuels, like coal and oil, and enables the adoption of renewable energy by providing a source of reliable, flexible power generation. In this way, LNG helps global customers to reduce greenhouse gas (GHG) emissions as they transition their energy systems to a lower-carbon future.
LNG can help improve air quality when displacing coal. The combustion of natural gas in place of other hydrocarbon sources can significantly reduce localized air pollution and public health risks in and around power generation sites. Estimates show that when used for power generation in natural gas combined-cycle power plants, natural gas emits virtually no mercury or particulate matter and can reduce nitrogen oxide (NOx) and sulfur dioxide (SO2) emissions by up to 82% and 99%, respectively, relative to coal on a lifecycle basis.
The International Energy Agency (IEA) estimates that switching from coal to natural gas has already helped limit the rise in global carbon dioxide (CO2) emissions since 2010 and avoided more than 646 million metric tons of CO2 emissions between 2010 and 2019.
In addition to fueling power generation, LNG is seeing an increase in use as both a road vehicle fuel and a marine fuel. The benefits of clean-burning LNG displacing traditional fuels such as diesel fuel (including low sulfur diesel fuel) or marine grade heavy fuel oil are similar to displacing coal in the power generation sector. This includes significant reductions in NOx and SO2 emissions as well as carbon monoxide (CO) and CO2 emissions. Additionally, using LNG as a fuel generates almost no particulate matter or soot emissions, which cannot be said for diesel fuel or heavy fuel oil.
The industry as a whole is committed to minimizing the environmental footprint of LNG by reducing methane emissions with innovative technologies through its production and transportation processes. This includes engagement of stakeholders and partners across the value chain, as well as participating in the development and implementation of scientifically sound, flexible, cost-effective policies.
MYTH: LNG is dangerous compared to other fuels
LNG has been the safest fuel for the last 50 years. LNG is colorless, odorless, non-toxic, and non-corrosive. Its high ignition temperature of 1200 °F (gasoline: 599 °F) and limited flammability range (5% to 15% in air) make its unintentional combustion highly unlikely. LNG, if exposed to the air, returns to its gaseous state and quickly dissipates and evaporates into the air leaving no residue. Unlike propane and diesel, LNG is NOT flammable when in a liquid state.
MYTH: Transporting LNG is dangerous
The truth is that LNG has an excellent transport safety record. Over the last 50 years, over 80,000 LNG cargoes have been delivered with no loss of cargo tank containment and no onboard fatalities attributable to LNG. Double-hulled with storage tanks, LNG carriers are among the most modern ships.
In the rare event of a spill, LNG is non-polluting because it quickly dissipates upon contact with air and water. So, whether a pipeline leak happened on land or a carrier lost cargo at sea, the gas would not harm the ecosystem.
Fears of LNG explosions are unfounded since natural gas is only explosive in its gaseous state under exactly the right conditions. The industry has well-developed technology and high safety standards to manage the conditions of natural gas and keep it in its liquid state.
MYTH: LNG is not a reliable fuel source
When the demand for fuel spikes, you’ll need a plentiful, affordable fuel source that can be delivered or stored on-site and converted quickly. U.S. Natural Gas supply is PLENTIFUL (approximately 92 years of domestic supply on hand), providing a reliable source no matter the season. This is important in polar vortex situations where the supply of fuel can be constrained and ultimately compromise operations. LNG can be used as a primary pipeline supply, a resource for emergency backup, peak shaving, or pipeline integrity.
MYTH: LNG is not cost-effective or cleaner
The current use of coal, diesel, heavy fuel oil (HFO) and marine gas oil (MGO / bunkering fuel) for Power Generation and Fuel for the shipping industry are major contributors to greenhouse gas emissions. Natural Gas and more specifically LNG (liquid natural gas) provides a viable and readily available solution to this specific use of Diesel, HFO and MGO. Remote Locations include island nations (i.e. Puerto Rico, the Caribbean, Dominican Republic, etc.)
MYTH: LNG trucks need refueling too often
Long hauls are an inevitable necessity for the transportation of goods. It can take a significant amount of time to get to the final destination, and the additional delays caused by needing to constantly refuel are an unwelcome nuisance.
However, the belief that trucks powered by LNG can only go a few hundred miles at a time is false. Recently, an Iveco Stralis NP 460hp truck completed a 1,073-mile haul without the need for refueling. It is considered to be the longest-ever journey by road on a single fill of LNG. According to Iveco, it saved about $244 in fuel costs for the outward journey – that’s 40% cheaper than using diesel.
MYTH: LNG emissions are just as bad as diesel
Since LNG is a fossil fuel like oil or coal, some believe it is counterproductive to use it as a way to protect the environment. While LNG does not guarantee zero emissions, it still is the cleanest burning fossil fuel around.
According to a 2015 Journal of Environmental Science and Technology study, diesel trucks emit more than 8 grams bhp/hour of nitrogen oxides, while LNG trucks produce just .2 NOx grams bhp/hour. Compared with a Euro VI diesel engine, a heavy-duty truck running on LNG emits 99% less particulate matter, and up to 15% less CO2, making it a far more environmentally friendly alternative.
MYTH: CO2 emissions from LNG are no less than that of coal
The truth is, that natural gas is a non-renewable fossil fuel, and like all fossil fuels it creates carbon dioxide (CO2) emissions. Too many emissions have harmed the earth’s atmosphere and reducing emissions worldwide, especially CO2 (carbon dioxide) is needed to help combat global warming and climate change.
Natural gas is the cleanest burning fossil fuel available at the moment. A natural gas power plant produces half as much carbon dioxide, less than a third as much nitrogen oxides, and one percent as much sulfur oxides as a coal-fired power plant.
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