Renewable Liquefied Natural Gas, or RLNG, is hitting the news radar as a potential solution for providing a renewable fuel source for vehicles on the road. But what is RLNG and is this really a possibility?
How is Conventional Liquefied Natural Gas produced?
Before we get to RLNG, lets take a look at conventional liquefied natural gas (LNG). Conventional natural gas formed when methane gases built up underground millions of years ago as decomposing plants and animals were compressed under many layers of sedimentary rock. Once extracted from deep in the earth, this material goes through a refining process to remove oil and condensate, water, other liquids, sulfur and carbon dioxide. Feeders transport the remaining substance–natural gas–to storage units. A significant benefit of natural gas is that the burned fuel emits fewer greenhouse gas emissions than other fossil fuels. Natural gas is often used to warm homes and provide electricity.
Natural gas can be transformed to a liquid form, LNG, for use in vehicles. To make LNG, the natural gas is cooled to a temperature of -260 degrees Fahrenheit. Once in this state, LNG has several unique features:
- It is highly compressed taking up only about 1/60th of its original volume.
- If spilled on dry ground, it evaporates immediately and leaves no residue.
- If spilled on water, it does not mix with the water and will not harm wildlife or impact water quality.
- If LNG is in an open environment, it will not explode when exposed to flame. In a confined environment, LNG will only burn when exposed to oxygen and fire; and it produces a candle like flame.
These factors combined make liquefied natural gas a very efficient and safe energy source.
According to the US Department of Energy, LNG fuels over 160,000 vehicles in the United States alone. Vehicles running on LNG can be dedicated (only running on LNG), bi-fuel (having two separate fuel systems to allow them to run on either gasoline of natural gas), or dual fuel (powered by natural gas but requiring diesel fuel for ignition assistance.) Currently, the best candidates for LNG are high-mileage, centrally fueled vehicles.
So what is Renewable Liquefied Natural Gas (RLNG)?
Renewable natural gas (RNG) is made from methane gases produced by decomposed plant or animal life, but rather than it being millions of years old, it is produced from recent decomposition, for example, our landfills. Escaping methane gases are trapped and purified to become RNG that can be used to heat homes and provide electricity in the same pipeline system as conventional natural gas.
This RNG can be further refined to a liquefied form, RLNG, with the same method of cooling used to produce conventional LNG. RLNG has the same properties as conventional LNG, with one additional significant benefit—it’s renewable! We can continue to produce more and more RLNG by trapping and transforming the methane gases from landfills across the United States. This also reduces our dependence on foreign nations to provide us with fuel and reduces negative impact to the environment from deep sea drilling and fracking. It’s a win-win all around!
Stay tuned later this month for part two of this article to learn how some states are utilizing Renewable Liquefied Natural Gas in fleet vehicles and what experts say about its future!
Want to learn more about how you can choose energy sources like Renewable Natural Gas?
Visit us at the Rogue Valley Clean Cities Coalition today! The Coalition works to enhance the livability and sustainability of Rogue Valley residents.