Natural Gas: the Past, Present, and Future
Natural Gas: the Past, Present, and Future
For millions of years, layers of decomposing prehistoric plants and animals have laid to rest beneath the Earth’s surface. Time, pressure, and intense heat have forced a chemical reaction that results in usable energy today. Hence the name: “fossil fuel”. Natural gas is the byproduct of the energy that plants and animals soaked up from the sun millions of years ago.
What is Natural Gas?
Natural gas is an abundant and naturally occurring hydrocarbon gas. It is primarily composed of methane (CH4) but can include alkalines and other gas compounds. Natural gas is the cleanest burning fossil fuel and is used for a variety of purposes in the United States.
Natural Gas Usage in the US (Annual Consumption by Sector)
- Electrical Power: 35% (10.59 trillion cubic feet)
- Industrial” 33% (10.6 trillion cubic feet)
- Residential: 17% (4.99 trillion cubic feet)
- Commercial: 12% (3.52 trillion cubic feet)
- Transportation: 3% (0.91 trillion cubic feet)
Dry and Wet Natural Gas
Dry Natural Gas
Dry natural gas is primarily composed of methane. It is more thermally mature than wet natural gas and has widespread commercial and residential uses that include cooking, heating, cooling, and fuel.
Wet Natural Gas
Wet natural gas contains a variety of “natural gas liquids” that must be removed before distributing to homes and businesses. Liquids include ethane, butane, propane, and pentane. Wet gas is more valuable because the liquid gases can be separated and sold as commodities.
How is Natural Gas Harvested and Transported?
Harvesting from a Natural Gas Reserve
Natural gas is harvested from a reserve by drilling a vertical well into the Earth’s surface. The gas naturally flows upward and into a collection plant. This can be wet or dry natural gas.
Harvesting Natural Gas from Landfills
Methane can also be harvested from landfills and the decomposition of plastics and organic waste. Many landfills have vents to allow methane to be harvested.
After collection, gas is moved through a series of pipelines into a processing plant, where it is treated to become pipeline-quality dry natural gas.
Natural Gas Treatment Process
- Oil removal
- Water removal
- Separation of natural gas liquids
- CO2 and sulfur removal
After treatment, natural gas is stored underground or in tanks for later use.
The Transportation of Natural Gas
When natural gas is transported, it is cooled to -260° Fahrenheit and shipped as liquefied natural gas (LNG). This is done because the volume of LNG is 600 times smaller than the gaseous form.
How Does Natural Gas Get To My Home?
Without thinking twice, we expect the convenience of commanding natural gas at the flip of a switch. But making this happen is a complex process that requires drilling, pumping, distributing, and monitoring the flow of natural gas.
- Drill a natural gas well thousands of feet into the ground and use heavy machinery to pump it to the surface. From here it is sent to a processing plant and readied for distribution.
- The gas is distributed to utility companies using a complex network of buried gas mains, similar to the interstate system. Utility companies distribute the gas for commercial and residential use through a series of pipes that get smaller and smaller as the process unfolds.
- The utility company’s pipes connect to a gas meter outside of homes and businesses, which measures the amount of natural gas used.
- Gas lines connect the meter to appliances, such as the furnace, water heater, dryer, and stove.
Environmental Impact and Sustainability
Although natural gas is a fossil fuel, the global warming emissions from its combustion are far lower than that of its counterparts. When compared to coal, natural gas produces 43% fewer carbon emissions for each unit of energy produced, and 30% less than oil. This is largely due to the fact that natural gas produces no physical waste.
Even still, the future demands more sustainable energy solutions.
The United States relies on natural gas for domestic use and as a lucrative export. However, domestic demand is projected to begin declining after 2035. As renewable energy sources and storage solutions become more viable, our use of natural gas and other fossil fuels will finally begin to burn out.