2 replies to this topic

[gosooners]

To all,

One of the method of purifying TEG/glycol is circulating stripping gas in the reboiler so that it reduces the partial pressure of water vapor above the glycol solution and as a result you can have high boil up rate of water and leave almost pure TEG. This is the fact i do know being a chemical engineer, but this thing i do wonder :

(1) I haven't seen any documentation of calculation for this system. How do you calculate how much partial pressure you are reducing with stripping gas comparing if you do glycol regeneration without using stripping gas ? Any publication will be helpful.
(2) How can you assume vapor-liquid equilibrium condition when you use Raoult's law ? In TEG stripper reboiler - most of the overhead of the reboiler close to the atmosphere pressure. It will be very useful if someone can show partial pressure calculation in reboiler overhead space.

i am looking for any engineering calculation/detail information for TEG regeneration with stripping gas. You can assume any particular number.

Thanks
gosooners

[ethylene]

check out "Gas conditioning and processing" by JM Campbell. Shell DEP also provide example.

[Zauberberg]

Look at GPSA, I'm attaching one page showing TEG vapor pressure, including Antoine coefficients as well. The same databook also contains charts showing TEG purity vs. stripping gas rate at several temperature levels.

Calculation of equilibrium conditions is given in various design standards (proprietary items), however GPSA offers fairly accurate procedure. A very good place to start.

 TEG.pdf   421.07KB   83 downloads