Namdaran Petrogas Industries (NPI) absorption packages are mostly used in separation processes in oil, gas and petrochemical industries since they have multiple usage of fluids to make the separation procedure more applicable by using MEG (mono ethylene glycol), TEG (tri ethylene glycol) and DEG diethylene glycol).
Absorption process is usually carried out under pressure using liquid solvent of higher molecular weight than that of the vapors being recovered. Vapors are separated from the rich solvent, which is recycled in the process as the lean solvent.
For a better performance the wet natural gas enters the absorption vessel (glycol contractor) near its bottom and flows upward through the bottom tray to the top tray and out at the top of the vessel. Usually six to eight trays are used .lean (dry) glycol is fed at the top of the vessel and it flows down from tray to tray, absorbing water vapor from natural gas. The rich (wet) glycol leaves the bottom of vessel to the glycol regeneration. The dry natural gas passes through mist mesh to the sales line.
Glycol regeneration unit is composed of reboiler where steam is generated from the water in the glycol. The stream is circulated through the packed section to strip water from the glycol. Stripped water and any lost hydrocarbons are vented at the top of the stripping column.