Chromatography is used in different industries to separate and identify specific components that make up a compound. It is an exacting process that requires gasses to be in an inert state as well as the maintenance of thermal stability for the successful separation of parts.
Gas chromatography is a separation technique to determine the composition of different compounds. In the oil and gas industry, it can be used to examine the quality and consistency of fuel and other products by detecting its composition.
Why Is It Important?
Olefins, saturates, and aromatics are types of hydrocarbons that make up petroleum and natural gas. Each of these elements has different effects on the quality, combustion, and emission of fuel. For example, a certain amount of olefin can contribute to smog caused by chemical reactions in the atmosphere. ASTM D1319 is an FIA (Fluorescent Indicator Absorption) method that can measure the total amounts of olefin and aromatics in gasoline. Other methods include ASTM D5186 and D6550.
Today, with innovative chromatography technologies, it is possible even for substances that aren’t very volatile to go through gas chromatography. Using supercritical fluid chromatography, or SFC, even heavy petroleum can be analyzed. Machines and more complicated techniques have been developed to make this possible.
How Is It Done?
Basically, the chromatographer takes a sample of the gas in the liquid form first and injects it into a tube that then vaporizes it. Once in gas form, the different kinds of gas that were combined to make the sample are pushed into a longer, coiling tube that separates them. These components are pushed by an inactive chemical that helps them travel through the tube after they are heated. It is integral that an inactive gas is used to prevent reactions with the sample. After the gas is passed through the tube, it goes into a detector box. Then, a chromatogram is created. This is where the levels of each chemical property are analyzed and compared. Unlike in liquid chromatography, it is possible to change the temperature in gas chromatography, giving you more control over the process of separation.
It’s a good thing that more and more people nowadays are more conscious about the products and pollutants that cause harm to the environment, particularly to the ozone layer. Testing and separating gas components has environmental benefits. Since gas in vehicles produces emissions, pollutants that can be harmful to the environment can also be determined by chromatography. This way, gasoline and petroleum products are tested before they are deployed to the market. Olefin that is a component in petroleum gas can also cause photochemical reactions resulting in smog in urban areas.
Overall, the technique of separation used by the petroleum industry is not only beneficial in testing its components. Gas chromatography is also a way to be aware of what big gasoline players in the market are producing and putting out into the environment.