7 replies to this topic

[Miguel]

hello.

i would like to know if anybody has detailed information of how the IFPEXOL process works.

it says in the prosernat web page www.prosernat.com that is a dehydration tecnology but it doesnt explain much. if someone could detail on it a little bit i would apreciate it

thank you

[Zauberberg]

Ifpexol uses deep-refrigerated methanol solvent, and is capable for simulatenous dehydration and dewpointing (Ifpex-1), and acid gas removal (Ifpex-2). Detailed information is not possible to get since it is proprietary technology - unless you know someone who is operating Ifpexol unit.

Look at the text below for some more information, extracted from Gas Processes handbook.

 IFPEXOL.JPG   187.26KB   60 downloads

[Qalander (Chem)]

Dear Zaberberg hello,

Definitely Nice info for me too!

Best regards
Qalander

[Miguel]

theres something i dont understand here , it says the process is cooled, but thats after , before or during the striping its expanded ?? because im interested in the dehydration process but if it doesnt use gas expansion do to my specs

[Zauberberg]

Unless you decide to go for adsorption (mole sieves, alumina) or absorption (glycol), some kind of expansion/cooling (or both) is definitely required in order to remove water from gas.

As I understood, Ifpex-1 works as simultaneous dehydration/dewpointing process, and hence the requirement for expansion/cooling. What you will choose for cooling purposes - external refrigeration, J-T valve, or turboexpander - depends on gas composition and pressure recovery requirements. For example, if dry gas pressure should be very close to the inlet gas pressure, you will certainly not use J-T valve but rather turbo-expander or MRU. Also, if inlet gas cricondenbar value is only slightly below the system operating pressure, you wouldn't take the risk to perform dehydration by refrigeration: it can happen that your gas will pass through the MRU without any condensation.

Best regards,

[Miguel]

thank you very much for your response.

now, do you think its viable to use these type of dehydration for inlet gas at 2500psig and 120F , with very little presure drop requirement at the outlet?
i already considered glycol absortion and adsortion but refrigeration is my 3rd option i dunno if i should discard yet
thank you for the help

[Zauberberg]

Hello Miguel,

It's easy to evaluate the technical feasibility of mechanical refrigeration - just plot the phase envelope of your inlet gas, and look for cricondenbar value (the maximum pressure at which two phases can exist). If cricondenbar of your gas is below 2500psig (and I believe it should be - especially if the gas is very lean), mechanical refrigeration cannot be applied for gas dewpointing/dehydration. More references you can find in the excellent book "Gas conditioning and processing" by J. Campbell.

Also, since you need to maintain the pressure of gas (if I understood you well, export gas pressure should be very close to the inlet gas pressure), J-T valve is automatically eliminated as a potential option. Therefore, turbo-expander unit remains as the only acceptable solution - as far as expansion/cooling is concerned.

However, I hope you realize that we are moving from pure gas dehydration process into combined dehydration/hydrocarbon dewpointing. If there is no need to remove heavier hydrocarbons from gas, considering the abovementioned options is not an economically feasible solution. Furthermore, low turbo-expander outlet temperatures could lead to hydrate/ice formation and equipment pluggage if gas is not dehydrated prior to entering expansion turbine. I believe this is why Ifpexol technology uses recirculating methanol in the "cold box" side of the process.

Best regards,

[Miguel]

thank you very much you have been of much help