Recycle Split-Vapor (RSV) Process

**hazulfahid** · 07-19-2011, 12:09 PM

Hi
Now I am developing Recycle Split-Vapor (RSV) process for NGL recovery process based on Ortloff but I encounter a problem. When I run this simulation, a consistency error has occurred. The composition at gas outlet for demethanizer in column environment and simulation environment is different. I don't know what to do. Below I attached my simulation. All your help is highly appreciated. Thank you

**thaihy** · 07-19-2011, 06:57 PM

This was my most exciting topic I spent a lot of time to play with but it is long time ago. We will turn it up.

I fixed the problem, but please will you share with me the process description as some of hot streams taken from the column could not be heated up by an ambient temp. stream.

**hazulfahid** · 07-19-2011, 07:16 PM

Do you have any idea how to solve it?

**thaihy** · 07-19-2011, 09:00 PM

You need to revise the position of the RCY-3 in the process, the model will be converged as RCY-3 is on stream #10.

**hazulfahid** · 07-20-2011, 07:30 AM

Dear Mr. Thaity,

About your previous question, from my reading, when a slip stream from or near the bottom of the demethanizer is utilized as a mixed refrigerant, it will providing refrigeration for inlet gas cooling otherwise normally accomplished using a costly external refrigeration system. The vapour generated from this "self-refrigeration" cycle is specifically tailored to enhance separation efficiency, then is recycled back to the bottom of the tower where it serves as a stripping gas. That is why I took two stream from bottom of demethanizer to integrate the heat with feed gas but I don't know exactly the specification I must put to the heat exchanger.

Anyway, after I incorporate your comment to put RCY-3 at stream 10, I still get consistency error about composition but at different stream. I still don't know how to solve that problem. Now, I confuse where to put recycle exactly since this is the 1st problem I encounter with recycle. Before this, all the simulation can solve using recycle. All your help is highly appreciated

**thaihy** · 07-20-2011, 11:02 AM

There are several US Patents regarding Gas processing technologies licensed by ORTLOFF such as SCORE, SRP, IOR, RSV...I had got them all but I lost them. I even don't remember the patent numbers, if you have any information please share with me.

I did correct the consistency error, will send you the model later if I could get correct spec for Side streams of the column.

Cheers,

**hazulfahid** · 07-20-2011, 12:40 PM

Dear Mr. Thaity,

I don't have US Patents since I just refer to some journal and article regarding NGL recovery process. I just know the gas feed, NGL product specification, and residue gas specification. I just simulate back the process flow diagram from the journal/article. The parameter of some equipment or stream in the simulation I just take from some journal/article too but not all parameter will be given at same journal/article. So, I just try and error until all simulation is solved. That is why I did. Since this is my study on NGL recovery, I thought that is ok. What do you think?

Sorry also I don't have exact column specification but I know the mole fraction ratio between methane and ethane and bottom of demethanizer must be less than 2%. If you don't mind, can you share the simulation? Sorry for troubling you.

Regards

**thaihy** · 07-20-2011, 05:24 PM

You may need to look at patents has been registered by Ortloff to have more details of process parameters such as temperature, pressure, theory tray numbers, stream spec...that should be a good start point to go further.

the attached is just to fix the problems you are facing, it is not expected as a completed model

**hazulfahid** · 07-20-2011, 09:53 PM

Dear Mr Thaity,

Thanks a lot for the simulation and the info. I will try to open it at my supervisor's HYSYS simulation since I am using old version HYSYS which is HYSYS 2006.

About the US patent, I also will try to find it. Since I don't know the Patent series no., so I will take some time to find it but I know it will worth with my studies. Thanks a lot for your help

Regards

**thaihy** · 07-21-2011, 04:06 AM

Give me your email address, I will send you some patents regarding Ortloff's NGL/LPG extraction process.

**hazulfahid** · 07-21-2011, 04:09 AM

This is my email. leon.hamidi88@gmail.com
Thanks for sharing

**hazulfahid** · 07-22-2011, 03:58 AM

Dear Mr.Thaihy,

I already install HYSYS 7.1 but I still cannot open the HYSYS RSV file. If you don't mind, can you convert the file to HYSYS 7.1? All your help is highly appreciated. Sorry for any inconvenience.

Regards