Natural Gas
Summary : Natural gas is the 5 th main pool of carbon and is extensively used in the modern economy for electricity, heating, and the making of plastics and petrochemicals. The way we define natural gas – as a fuel to burn - consisting of methane and natural gas liquids that include ethane, butane and propane. ( Natural gas liquids are gases at surface temperatures and pressures and must be separated from methane by refining processes at elevated pressures and lower temperatures). The most commonly occurring form of what we call natural gas is from late-stage oil generation under the Earth. When lipid-containing algae is converted to petroleum, it first forms oil, a mixture of long-chain hydrogen and carbon atoms. With increased pressure and temperature from deeper burial in the E arth, oil is naturally refined or “cracked” into prog ressively shorter chains of hydrogen and carbon whose end member is methane (CH4), the simplest of these molecules. Modern oil refineries replicate these natural processes using technology (and lots of energy, heat and pressure). The source material for most oil-which-becomes-gas is from preserved marine organic carbon that mostly comes from various forms of algae. Another source of natural gas is from preserved non-marine organic carbon derived from land plants. This type of carbon lacks the complex, long-
181
Powered by FlippingBook