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Molsieve separation for O2 and N2
Posted: Wed Aug 13, 2014 6:18 am
by bijish
We have an agilent 7890 natural gas analyzer with Hayesep Q (3 ft and 6 ft), Molsieve 13X 10 ft and PONA column 50 m. TCD detects O2, N2 and methane from Molsieve column, but the separation of O2 and N2 is poor in Molsieve 13X. Could someone help?
Re: Molsieve separation for O2 and N2
Posted: Wed Aug 13, 2014 6:31 am
by kubowicz.tomasz
Hello
Perhaps you need to regenerate Molsieve column. Common way is baking out in ~300°C for couple of hours.
Regards
Tomasz Kubowicz
Re: Molsieve separation for O2 and N2
Posted: Thu Aug 14, 2014 8:16 pm
by muGC
Or perhaps your valve timing is wrong and the oxygen is not getting on to the Molsieve. It is possible to lose the oxygen peak as it is the first to elute from the Molsieve column with your method.
Re: Molsieve separation for O2 and N2
Posted: Fri Aug 15, 2014 1:05 pm
by bijish
Or perhaps your valve timing is wrong and the oxygen is not getting on to the Molsieve. It is possible to lose the oxygen peak as it is the first to elute from the Molsieve column with your method.
When ww inject air for O2 calibration, we detect oxygen and nitrogen peaks, but poor separation...
Re: Molsieve separation for O2 and N2
Posted: Wed Sep 03, 2014 10:35 pm
by Jonezy_Lothos
Sounds like you need to bake out your molsieve. Be sure to remove it from the GC, you valves can not take the heat. Make sure you bake it out with flow.
have fun,
Jones
Re: Molsieve separation for O2 and N2
Posted: Tue Sep 16, 2014 6:35 pm
by isalas
You can also move from Molsieve 13x to Molsieve 5A. This should give you a better separation of components.