Your post has grammatical, spelling, spacing, punctuation, and other English errors and perhaps you meant to write the following:
"I am a trainee chemical engineer working since November 2013 in a Gas sweetening and gas dehydration plant. Our plant’s design production capacity is 30 MMScfd but currently we are running it at only 10 MMScfd.
Feed Sour Gas specifications are:
Pressure = 850 psig to 880 psigvaries with ambient condition
H2S = 400 ppm
CO2 = 4 mole %
Our Client Requirement is:
H2S = 5 ppm
CO2 = less than 3 mole percent
Moisture = 10 lb/MMScfd
TEG Circulation = 7 gpm, employing Kimray pumps
What will be the effect of running TEG under such conditions? One of the reasons explained to me is that once there was severe foaming in the amine section and that’s why the amine carried over to the TEG section.
When we make up TEG with fresh drum there is minimal change in its pH, say 8.9, but after some time it again sustains the value of 9.0. What are long term and short term drawbacks with this on Kimray pumps, sock and carbon filters, fire tube reboiler, and absorption tower or any other worse prospect of this."
If so, then allow me to point out the following:
You don’t specifically state what your basic problem is. Do you mean that your unit has experienced entrainment of amine (which amine? DEA, MDEA?) from your amine absorber to your TEG absorber (because you have no adequate intermediate knock out drum or water wash system)? That being the case, you have a serious processing problem that was not accounted for in your unit’s design stage. Who, specifically designed and built your amine and TEG units? Your problem seems to be even more serious than the usual because you are only operating at 33% of your design capacity. This problem will surely become worse as the actual production increases in the future. Your TEG is getting contaminated with the entrained amine. This is a common occurrence in badly designed gas treating units and something that should have been contemplated and resolved at the design stage. But that is of no importance to you now; you have inherited a bad problem and with little resources to resolve it.
One thing in your favor is the relatively high water content in the dehydrated product gas that is being accepted by your purchaser. The usual criteria for this application is 7 lb/MMScfd as maximum content in the purchaser’s pipeline and 4-5 lb/MMScfd design water content out of the TEG absorber. Your contaminated TEG is continuing to operate (although it eventually will have to be replaced) due to the acceptable high water content in the product gas.
With continued amine contamination, nothing good can be expected from your TEG operation. Your Kimray pumps and major equipment won’t be adversely affected for now, but your ability to maintain the product specification will start to diminish and if the situation gets even worse, you may start to degenerate TEG into portentially corrosive products. Basically, you are not supposed to have any amine in your TEG - and your unit is violating that basic requirement. To remedy the situation, you need to arrest the migration of amine into the TEG. You can do this in several ways - some more expensive than others. The various methods are subject for another thread.
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