Chromatography Forum

I need to carry out the testing of C2H4 gas (99.9% Purity) to confirm on the concentration. Please help as I’m very new to GC
a)What’s the method to analyze C2H4 (99.9% Purity)?
b)Which detector to be used – FID or PID? Very confuse.
c)What column will be the most suitable to carry out the testing?
d)Sampling method?
e)Reference?
f)Do I require to buy standard C2H4 gas

I also need to purchase new GC for this test, I’m not sure which want will be better, a new model or a demo set (my company will save 30k)

Thank you very much.

Regards,
Jack

New to GC?

You are taking on a major project which requires multidimensional chromatography. Are you capable of doing this task well?

You will need to analyze the gas for the following possible contamination:

air (nitrogen and oxygen, leaks in your pipeline)
methane (0-250 ppm usually)
ethane (biggest individual impurity in ethylene, up to 2000 ppm)
acetylene (0-5 ppm usually)
Carbon dioxide (depends)
(possibly carbon monoxide)
Propylene (C3s are usually less than 500 ppm)
propane
C4+

Determine which contaminants are the most important to you and the levels in which you wish to know their presence before you buy the hardwqre.

If at levels over 1000 ppm then TCD is the best choice. If ppm levels then you will need an FID. Also a methanizer if you wish to measure low levels of CO and CO2.

Of course, you could buy a HID and then you won't need an FID or a TCD but possibly a lot of maintenance. A dual detector GC with 5 valves should be an adequate solution.

Arnel, Wasson, or one of the major process analyzer suppliers are possible sources of equipment. (Siemens AAI, ABB, Foxboro (Hamilton Sunstrand) Yokagowa, etc My apologies to those I left out. Too many to list).

best wishes,

Rod