Chromatography Forum

Hi.
I want to check the GC methanizer to measure CO2.
I have checked valves, flows, columns, but I do not see a peak.
I have thought to manually inject a mixture of CO2 and H2 into the methanizer inlet (to make the reaction). And expect the FID to give me signs of life.
I have a 50ppm CO2 bottle. I have thought to dilute with N2 (to get 5-10 ppm of CO2) and add some H2.
Would this test be correct?
Any suggestion?
Thank you

A few more details would help such as make of GC and column used and flows you are using.

Gasman

Hi.
Sorry for not giving more details.
It is an industrial process GC. It's an ABB PGC3100 (it's a few years old ...)
It has a FID for CO2 and TCD for N2.
The CO2 part has two valves with three HAYESEP Q columns.
The column flow rates are 35ml / min. Backfush 60ml / min.
Column temperatures are fixed at 90ºC.
The methanizer is at 440ºC.
The range is 4ppm for CO2.
Today I tried to inject the methanizer with a diluted CO2 mixture.
The FID has not detected anything. Sorry, the FID has had fluctuations but they were due to the flow variation while I injected.
Then I injected 2ppm of CH4, and the FID has detected a large spike.
With the tests that I have done today, I think that the methanizer does not work well.
Tomorrow I will try to check the methanizer.
If someone can give me an idea or suggestion, I appreciate it.
Thank you.

I am not familiar with the ABB instruments, but it looks as though you will need to replace the nickel catalyst packing as it may have become contaminated.

Gas man

Start by sending the standard all the way through. With three columns, you probably have a backflush and a cut to analytical and if the flows are messed up you would miss the cut window. Tell all the valves to send the sample straight to the detector and see if you get a peak. N2 won't show up, just the CO2.

For the purposes of this test, you might extend the run time for a bit as well because you might increase the resistance of the primary pressure controller some by having all three columns lined up.

Best regards,

AICMM

I have already tried to send the standard through all three columns to the detector, and I have not got a signal.
I have also extended the runtime. For that reason, I suspected that the methanizer was not working.
I have already managed to find the problem.
The methanizer temperature !!!! (This equipment does not display the temperature). The heating resistance was broken.
Resolved
Thanks for your time.
best regard