5 replies to this topic

[vsnlbom]

We are in process of adding module for HC dew-pointing in existing facility. Considering the project constrains and available facilities, we have selected JT valve based HC dew pointing unit. Existing process primarily consist of separation, dehydration and compression facilities.

 

Based on requirement methanol/ MEG is not being added to suppress hydrate formation temperature. This leading to bottleneck in terms of minimum temperature which can be achieved downstream of JT valve.

 

Can any one suggest minimum temperature difference; to be maintained between JT valve downstream and hydrate formation temperature. Ideally we would like to have as minimum as possible; looking for best industry practice.

 

 

[cylai]

I don't think you will find an answer to 'hydrate formation temperature' as it is dependent on your compositions. Secondly, there are no indications regarding initial conditions, export conditions, what are the utilities available and so on. Good luck and hope someone is able to suggest you an answer without any information.

[serra]

as said by cylai the hydrate formation temperature depends from gas composition and conditions and,

in general, it is not a constant value,

given regular readings of composition (for example from a GC) you may estimate hydrate formation temperature with a software

(normal accuracy being within 1-2 C) and modify the set point of your JT when required,

for some details see

"http://www.cheresour...ate-formation/"

[Neelakantan]

I find many a time in this forum, that, operating engineers bring in a scenario like a story writer a plot and some characters; being an engineering forum, we can have discussions on two levels :  general chatter- experience, expectations, general questions etc and specific discussions: a particular situation, bottleneck or a problem, suggested solutions or alternatives.

 

but when you write a requirement like OP, to get a realistic engineering solution we need details details details details....

 

1) you say you have dehydration facility; what sort and if it is before DPC why you need methanol or MEG?

2) and why the restraint of not adding methanol and MEG?

3) why you need a HC dew point control in the existing system? changed composition? or contract change?

4) no mention about op P/T?

5) if you drop pressure for JT how you match the original operating pressure in downstream units?

 

 

regards

neelakantan

[vsnlbom]

Dear Mr. Neelakantam,

 

Thanks for reply. Most of the time I have used this forum to get more general information based on experience and to get basic guidelines. I believe sharing details many times in open forum has lot of IP issues which I have to take care. In addition, to get specific solutions I can always approach consultants and vendors.

 

If you have any details on my question please share.

[Napo]

Vsnlbom,

 

I send you some information, it´s from the book: Project Development for Gas processing Plants and Facilities, by Donnelly R., 2nd ed., 1982.

 

Napo.

Attached Files

•  Joule-Thompson.pdf.pdf   261.4KB   31 downloads