Gas purifiers are necessary because they help in providing clean gas, which can guarantee the quality and reliability of gas chromatographic results. Furthermore, as gas purifiers minimize sensor noise and extend the life of the column. Gas purifiers are like insurance policies to protect equipment and other analytical columns from different types of contaminants. Still, gas purifiers will not be able to convert low gas purity requirements in high purity gases. Because of this important factor, it is necessary to choose the right grade of gas with different purity criteria for the proper use into the gas chromatography applications.
Selection of Right Gas Purifier to Suit your application
Various types of gas purifiers are available in the market. While some gas purifiers remove just one specific contaminants, remove other types of multiple pollutants simultaneously from the air stream. You need to consider several factors in the selection process gas purifiers, taking into account specific applications. These factors will include potential contaminants in the air stream, restrictions on the flow and pressure levels of gas purity required, appropriate comfort instead of used gas traps and space availability.
Common traps Used in Gas Purifiers
Oxygen, hydrocarbons, carbon dioxide and moisture traps are common purifiers used in the majority of gas chromatography (GC) program. Oxygen traps are usually packed with metal catalysts. Oxygen is considered harmful contaminating gas in all analytical columns. Oxygen is able to produce an irreversible oxidation wave damage, especially to polar phase. Hydrocarbon traps are usually packed with activated charcoal, which can absorb organic compounds that are larger than methane. Still, size and molecular weight organic pollutants will be a certain impact on the ability of hydrocarbon trap to a great extent but it will also consider the value of efficiency to some extent. Activated charcoal possesses higher capacity to trap higher hydrocarbons greater than C4, compared to smaller hydrocarbons, which are less than C4. Moisture traps are usually packed with unique molecular sieve. When taken to a high temperature, are crystalline structures forced to lose their watering or water content. This open pit gets filled readily with any compound that fits the pit. Water fits perfectly into the cavity, but this value will also be able to remove gases such as carbon dioxide, sulfur dioxide, hydrogen chloride and chlorine, or other gases that have an effective diameter smaller than water.
The process contaminants affect Gas Stream
If you want to understand how contaminants affect the gas flow, you need to follow the path of the carrier gas takes to get the gas chromatograph. This trail is usable for gas sensor fuel also. The gases start from the gas tank or a separate gas generator. The gas passes through a long tube length, pressure gauges, valves, and other equipment. Each one of these areas is the potential culprit to introduce contaminants into the gas stream. This results not only in humiliating results column but also shortens the life of the column CG.
Major contaminants such as oxygen, hydrocarbons, and moisture are able wreaking havoc with the columns and the detector from CG. Packed and capillary columns can get easily degraded when exposed to oxygen or moisture, especially at high temperatures. These contaminants will also compromise sensor performance. Since the sensor actually “see” pollutant result is a baseline noise, spikes, and drives.
It is advisable to install gas purifiers vertical wall mounted types to avoid driving. Redirect occurs when you install the gas purifier in a horizontal position. Gas purifiers are available as compact panels with many purifiers or one card that has multi-absorbent capacity.