Introduction
During the 1990s, more and more power plants began to use natural gas for electrical generation, increasing the demand for this resource. With this increase in demand, the natural gas industry was pushed to become an innovative leader in technological advancement. Innovative technologies in exploration and production have been able to decrease the environmental impact of drilling and extraction at well sites, increase the useful life of wells, increase the amount of gas that can be extracted from sites, and allow the industry to find new, safer ways to transport and store this resource.
LNG Tanker
Image: alaska-gas-pipeline.blogspot.com
LNG (Liquefied Natural Gas)
When natural gas is cooled at normal pressure to approximately -260°F, it condenses into a liquid form known as LNG (Liquefied Natural Gas). In the process of liquification, oxygen, carbon dioxide, sulfur, and water are removed from the gas, resulting in almost pure methane; LNG and LNG vapors will not ignite in an unconfined environment. LNG is transported in insulated tankers where it is kept in liquid form by the process of autorefrigeration, a process where LNG is kept at its boiling point and any added heat is countered by energy loss from LNG vapor; this vapor is vented out of the storage vessel and used to power the tanker.1
CNG (Compressed Natural Gas)
Natural gas can be compressed to less than 1% of its volume to create CNG (Compressed Natural Gas), which is stored and distributed at a pressure of 2,900-3,600 psi. CNG burns cleaner than other forms of natural gas, and is easier to mitigate in spills since it disperses so quickly. CNG is currently used in million of modified vehicles worldwide, and the fuel proves to lessen the need for car maintenance since it burns cleaner and easier on vehicle components. Unfortunately, compressed gas requires more storage space than conventional gasoline, but manufacturers have created innovative storage techniques to minimize the amount of trunk or car space the gas cylinders occupy.
NGLs (Natural Gas Liquids)
NGLs (Natural Gas Liquids) are different from LNG in that they appear in liquid form at the surface in field facilities or processing plants without refrigeration. NGLs include propane, butane, pentane, hexane and heptane and are categorized according to their vapor pressure.2 NGL is often found in association with other fossil fuels (such as oil), and can sometimes be dissolved into other products. The process of deriving usable natural gas liquids is quite complex and difficult, and requires large plants to extract and clean the fuel.
GTL (Gas to Liquids)
GTL (Gas-to-liquids) technology is a method of converting natural gas to a hydrocarbon mixture which can be upgraded to petroleum products. The technology dates back to 1923 when German scientists Franz Fischer and Hans Tropsch invented the process (Fischer-Tropsch fuels). This technology can be viewed as an alternative to crude oil refining, because natural gas can be used to create petroleum products such as diesel.