Amine Unit Filter - Carbon Particle Carryover

[ARCH01]

We're proceeding with the design of an amine unit. The carbon filter design includes a Johnson screen with 0.011" slots. A question has been brought to determine if a guard filter is required downstream of the carbon bed to prevent carryover of carbon particles into the regeneration column. I would like feedback whether the guard (particulate) filter or duplex strainer is necessary considering that the carbon bed filter has a built-in screen.

 

[RogerH]

Arch1
All designs I have seen with Carbon filters do have a downstream particle filter at about 10um. Although I havent seen the carbon filter myself I heard that it does contain some black deposits which I assume is carbon fines. The screens will only hold large carbon particles in the mm size and the filter will capture the um sized ones. If chose not to install an afterfilter you run the risk to foam up your contactor(s) due to carbon fines.

 

[bspooner]

We always suggest a particle filter after a carbon bed. 5 or 10 micron absolute should last you a good 6 months. Equally important is to properly load the carbon into a wet vessel and backflush thouroughly before brining the amine online.

 

[sbush]

Carbon black ranges in the 0.01 to 0.30 micron range. If carbon black could be detremental to the downstream process, then you might want to consider ultrafiltration (typically 0.005 microns).

You might also consider the fact that coconut shell-based carbons are significantly harder than peat-based or coal-based. They tend to produce the least amount of carbon fines and sloughage. They also have the greatest surface area and activity (iodine number), by comparison.

S. Bush

http://www.water-eg.com

 

[TexasOE]

The downstream carbon filters aren't really needed for the day to day carbon escaping the filter because this is a small amont. The main reason to have the filter is to act as a back up incase all the carbon is released from the filter. If there is not filter to catch the carbon the particals will make there way into the towers and cause a foaming problem in your regenerators bad enough to shut down everything.