1 reply to this topic

[psugis]

We are currently operating 4 teg units each one of them will manage the flow for 2 gas compressors, this will give us a total of 8 reciprocating compressors. At the moment we have on line 7 gas compressors and 3 TEG units, we are seeing some glycol carryover on the gas stream after the contactor tower, we also have a post TEG coalescer filter and we see the gas dowstream the coalescer.

Can someone support me and let me now why does this happen? Is the gas velocity important to deal with this issue? If I increase the pressure or reduce the gas rate will fix the problem?

Each unit handle about 39 MMSCFD and each compressor is about 18 MMSCFD.

Regards,

Paul Sugis

[Art Montemayor]

Paul:

We can’t begin to explain why you should be experiencing excessive TEG carryover from your TEG Contactor tower since we don’t have detailed calculations or drawings of the unit. We don’t know who designed and fabricated your units. We don’t know the operating conditions – such as flow rates, temperatures, & pressures.

All we can really comment on are generalities that include the superficial gas velocity through the Contactor, the glycol flow rate, the disengagement space allowed on top of the contactor, and the temperature and pressure of the glycol entering the contactor.

I can’t predict if increasing the pressure or reducing the gas rate will FIX the problem. I can only comment that doing so will alleviate the problem – how much depends on the local conditions and existing design.

I can only judge by my past experience in designing, starting up, and operating TEG units out in the field. I never experienced any excessive TEG losses or carryover. Maybe I was lucky; maybe I was good at what I did. What I do know is that I always applied expert engineering judgment supplied by my mentors and those experts that taught me the basics in natural gas dehydrating. By applying conservative design and common sense judgment, I never ran into situations that were un-solvable. Certainly, TEG losses exist. But they exist for distinct and explicit reasons and they all can be resolved if the initial and prevailing causes are removed or resolved. The trick is finding and identifying the causes. Many times, the causes are a result of sloppy engineering design and/or fabrication of the TEG unit. Other reasons may lie in the operation.

What, specifically, do you mean by: “we are seeing some glycol carryover on the gas stream after the contactor tower, we also have a post TEG coalescer filter and we see the gas dowstream the coalescer”? How do you visually “see” the TEG losses? What do you mean by “seeing the gas” after the coalescer?