glycol seperation

[chil500]

I was thinking of ways to get better efficiency from a filtration system (activated carbon)used on a glycol dehy unit. Knowing that the entrained hydrocarbons are usually removed with the carbon, I was thinking along the lines of building a hydrocyclone to possibly help knock out the heavier contaminants before the filter. What do you think?

 

[monaco8774]

Problem is what do you do with the reject liquids, cant just throw it away without increasing your operating costs.

 

[chil500]

The heavy filtrate will be filtered seperatly from the rest of the unit but i am thinking that if the cyclone works appropriatly all that is remaining will be sludge which cannot be used for anything else. The glycol that passes through the cyclone will be further filtered through activacted carbon and other filters to then be returned to the supply tank.

 

[maddocks]

We've actually heard of a few operator's using a centrifuge for this service - apparently the foaming has dropped dramatically and they are using less filter cartridges. Most centrifuge companies have a mobile service - a 2-5% slipstream over several weeks can clean things up nicely.

 

[chil500]

Thanks Maddocks,
I have developed a unit at this time which will clean a dirty(black) glycol dehy unit (700 gallon) back to clear in about 14 hours but it takes at least one change of filters in the field. I was thinking that if I could remove a greater amount of heavies through mechanical means then that would cut the load on the filter bed and other elements. Knowing that a centrifuge will take a power source, lots of space and moving parts, does any one think that a hydrocyclone will be as effective simply by using the pressure of the TEG pump and volume?

 

[monaco8774]

Usually these systems have a positive displacement pump to bring pressure back to contactor, then as long as you are operating the contactor sufficiently below the maximum discharge pressure of the pump you could use a hydrocylclone, however problem is you would then have to design the hydrocyclone for higher pressures, also the reject on a hydrocyclone is typically 2% of flow in so you would need to manage that somehow.

All the teg units I have worked on have a cartridge filter upstream of the activated carbon filter, to protect it, i dont see how a hydrocyclone could do a better job than the cartridge filter?