How is Chromatography Used in Petroleum Refining?

Chromatography is one of the most widely used analytical and separation techniques in the processing and manufacturing industries. The name chromatography is derived from the Greek for colour writing and was first developed early in the twentieth century in Russia by Mikhail Tsvet to separate plant pigments.

Nowadays, chromatography is a multibillion-dollar industry and is found in most analytical, development and quality laboratories around the world. The basic principles behind chromatography are simple - a sample is carried across a stationary phase by a mobile phase which causes the sample to be separated into its individual components that are then ‘seen’ by a detector. And chromatography can offer a great deal to the petroleum industry. Let’s take a look at a few insights.

Gas chromatography monitors the petroleum industry

When it comes to the petroleum industry - gas chromatography is king. This is due to the fact that gas chromatography is the best system for analysing volatiles. And many of the compounds in the petroleum industry are easy to convert to a gas. Gas chromatography is used to analyse both finished products and in-process samples.

Gas chromatography systems are simple really. They comprise an injection system to add the sample, a chromatography column to allow the components to separate and a detector to sense when a component is exiting the system. And it is in the range of detectors available to the petroleum industry that makes gas chromatography flexible.

To optimise the system, it is important to match the detector to the application. Gas chromatography uses several types of detectors that are compatible with the petroleum industry:

• Flame photometric detectors for sulphur in residues,
• Photoionization detectors are used for BTX and other aromatics,
• Thermal conductivity detectors are used to measure inorganic gases in workspaces, and
•  Flame ionization detectors analyse refinery streams.

Designed for the industry

Because of the nature of the petroleum industry, on line analysis plays an important part of the process. This is carried out using gas chromatography but with a range of equipment developed specifically for the petroleum industry. These include; analysers developed for simulating distillation separation of crude oils to optimise the yields and quality, analysis of natural gas for BTU content and hydrocarbon composition, and analysis of refinery gases.

But as the petroleum industry develops, so to must the gas chromatography methods and techniques that keep the method at the forefront of analysis. Better columns and detectors are developed that offer greater sensitivity and resolution. To keep up with technology, analysts need the tools to help develop better methods - a topic covered in the video in this article, Using Free, High-Performance, Computer Modeling Software to Simulate Gas Chromatographic Separations.