Upgrading a GC or a brand new one?
Posted: Thu Aug 14, 2014 12:26 pm
Hello,
After a few months, I am back with some new GC-related existential problems and I look again for your kind help
Here's our issue: we need a system to analyze CO, H2, and hydrocarbons (CH4, C2H4) in a CO2 stream down to the low ppm level. I've been getting decent results so far for CO with a ShinCarbon ST column and the TCD, but now we need the complete deal, meaning that we have to upgrade to a TCD/FID+Methanizer setup in order to be able to determine all of these components reliably and with a low limit of detection.
Our GC is equipped with a TCD and an FID, so we have received a quote for an upgrade by adding a methanizer to our 6890. The TCD and the FID (the capillary-optimized version) are already installed in the GC. The idea is to install the FID and the methanizer in series with the TCD, adding a valve in between to vent CO2 before it reaches the methanizer and avoid deactivating the catalyst too quickly (seeing that our samples are almost completely CO2). The layout of the proposed upgrade is this one:
Alright, so this looks pretty standard. However, I am a bit skeptical about the suggestion of a single capillary column for this application; most references I have read use a [packed] polar column to retain CO2 and then separate the other components in a Molsieve column. Do you have any experience performing this analysis on a GS-CarbonPLOT column?
On the other hand, we have received a quote from a brand-new GC from SRI (the Multi-Gas #3 configuration), with the two detectors, the methanizer and two packed columns for a very competitive price compared to the upgrade. We have no experience with SRI and we were looking for any opinions or suggestions, particularly in regards to their reliability, ease of use and technical support.
Any help or comments are greatly appreciated. Thanks in advance!
After a few months, I am back with some new GC-related existential problems and I look again for your kind help
Here's our issue: we need a system to analyze CO, H2, and hydrocarbons (CH4, C2H4) in a CO2 stream down to the low ppm level. I've been getting decent results so far for CO with a ShinCarbon ST column and the TCD, but now we need the complete deal, meaning that we have to upgrade to a TCD/FID+Methanizer setup in order to be able to determine all of these components reliably and with a low limit of detection.
Our GC is equipped with a TCD and an FID, so we have received a quote for an upgrade by adding a methanizer to our 6890. The TCD and the FID (the capillary-optimized version) are already installed in the GC. The idea is to install the FID and the methanizer in series with the TCD, adding a valve in between to vent CO2 before it reaches the methanizer and avoid deactivating the catalyst too quickly (seeing that our samples are almost completely CO2). The layout of the proposed upgrade is this one:
Alright, so this looks pretty standard. However, I am a bit skeptical about the suggestion of a single capillary column for this application; most references I have read use a [packed] polar column to retain CO2 and then separate the other components in a Molsieve column. Do you have any experience performing this analysis on a GS-CarbonPLOT column?
On the other hand, we have received a quote from a brand-new GC from SRI (the Multi-Gas #3 configuration), with the two detectors, the methanizer and two packed columns for a very competitive price compared to the upgrade. We have no experience with SRI and we were looking for any opinions or suggestions, particularly in regards to their reliability, ease of use and technical support.
Any help or comments are greatly appreciated. Thanks in advance!