carbon filter replacement standard

[nury97]

Dear all,

I'm working in carbon filter company(exEA carbon filter).
I want to know "carbon filter replacement standard".

In my country,
Usually most of refinery replaced carbon filter once a year.
They said "if pressure drop across the carbon bed exceed above 1kg/cm2, replace carbon filter".

I want to know phenomena occured that determines the replacement of the activated carbon except pressure drop.

<correct carbon replacement standard>
*foam tendency
replacement > foam tendency value(seconds)
*hydrocarbon concentration
replacement < amine's hydrocarbon concentration drop(inlet/outlet)
*amine color
replacement > APHA value (or yellow,brown,dark brown,black)

It's so hard to explain my question in English.
And I have no operating experience on the spot.
Please fulfil my question, thank you very much!

with the best regards,
AES

 

[Jason5000]

I've always heard that pressure drop is not a good leading indicator that a carbon filter is spent in an amine system. You're counting on the filter to adsorb hydrocarbons, grease, antifoam and the like, and that is more of a surface active phenomenon. By the time a pressure drop increase is noted the filter is likely already spent.

Some studies were done at the site I work at on looking at oil & grease results in and out of the filter as well as some other measures, but the results were pretty inconclusive on detecting when the carbon filter was spent.

Waiting until absorbers start foaming is not exactly a good monitoring point, and I've never had great success with foam height/stability testing either.

We've resigned ourselves to changing out carbon filters on a time based schedule that we know from historical experience will keep us out of trouble in terms of foaming tendency. 1 - 3 times per year depending on service is what we do.

 

[Zapster]

Can you have a test port on the discharge vent of the carbon filter? If so, it might require a periodic gas analysis to ensure emission compliance is upheld in addition to monitoring the delta P across the filter.