Chromatography is the science in which a blended substance is separated into individual and measurable components. We often see chromatography for the first time in elementary science class. We use a marker or pen to make a mark on a piece of paper. Then, the end of the paper is submerged in water and as the water moves up the paper, it separates the colours that the marker or pen is made up of. This is called Paper Chromatography and we have demonstrated the basics of chromatography: the mobile phase (water), the stationary phase (paper), and the sample (marker ink).
The mobile phase, stationary phase, and sample are present for every type of chromatography. In process gas chromatography, the mobile phase is typically either hydrogen or helium (carrier gas), the stationary phase are the columns, and the sample is the process being analyzed. As the carrier gas moves through the gas chromatograph, it brings with it the sample. This sample will move through a series of columns and separates into its individual components. Measured components can be anything from methane to nonane, nitrogen to carbon dioxide or hydrogen sulfide to pure hydrogen.
As each separated component moves out of the column, we say that the components are eluting. Components will elute in a specific order and that will not change, however, components can elute faster or slower depending on a couple of factors. Increased carrier gas pressure and oven temperature can cause decreased elution times. However, this can cause a problem where components may overlap as they pass the sensor. Concentrations of overlapping components will be misrepresented by the analyzer and values will be inaccurate. With a colder oven and/or a decreased carrier pressure, components will not move through the analyzer in the time specified by the designer. Because the components won’t have made it through the analyzer, they will be caught in the next analysis and therefore cause another inaccurate reading.
Envent has spent the last few years developing our gas chromatograph. One of the primary features we focused on developing was our analytical oven. With improved insulation, sealing materials and an overall better oven design, we have reached new levels in temperature stability. Testing in our environmental chamber, we tested the oven in ambient conditions as low as -18° Celsius and as high as 55° Celsius with no more than a 0.05° Celsius change over the range. Moving to a contact heater rather than an air-bath style we can manage less heat loss on the TCD, even with the oven door open during maintenance. This stability along with the maintenance personnel in mind, makes the Envent gas chromatograph infinitely user friendly. Also, new user software has been developed to give a more familiar and friendly interface when interacting with the analyzer.
With both a Division 1 and Division 2 option, Envent engineers each analyzer to the customers process specifications. We separate our gas chromatographs into two categories, the BTU GC and the Process GC. Our BTU GC looks to measure methane through to both iso and normal pentanes as well as a hexane and heavier components, carbon dioxide and nitrogen. Process gas chromatographs are specific to the measurement needs. These applications are all run by Envent’s in-house team of chromatographers, who design each of the column sets to ensure the highest standards and maximum repeatability.
Learn more about our Gas Chromatograph options here.
Envent has made great strides to develop a high quality and high standard gas chromatograph. Our skilled technicians and trained staff all have a part and say in the development ensuring that the best quality product leaves our doors.
About Envent
Based in Calgary, Alberta, Envent was formed to design and manufacture process analyzers primarily for the oil and natural gas industry. We currently produce H2S Analyzers, Total Sulfur Analyzers, Moisture Monitors, CO2 Analyzers, O2 Analyzers, Optical Hydrocarbon Analyzers and Gas Chromatographs. Our goal is to have quick delivery for our standard systems. Sales and service support for our customers is unsurpassed in the market.