Gas Dehydration unit PSP-GP

As a superstructure with rich experience in installation, maintenance and servicing of hydrocarbon transport system equipment, Feromihin has produced a gas dehydration unit. This unit will soon be installed at the new underground gas storage under construction – PSP Grubišno polje.

The manufactured gas dehydration unit using TEG serves to remove residual moisture from the gas before it enters the “Plinacro” transport system and consists of three parts:

1. Dehydration column and cooler of dry TEG,
2. Regeneration skid, and
3. Pumps and condenser skid.

Natural gas from gas wells, after rough separation of water and condensate, is sent to a unit to remove residual moisture.

What happens in the dehydration process? Triethylene glycol (TEG) is utilized in a column to remove moisture from natural gas through a counter-current flow, with natural gas entering from the bottom and TEG, responsible for separating moisture, descending from the top of the column. This method ensures efficient dehydration by maximizing contact between the gas and TEG for moisture absorption.

The dehydration unit releases the dehydrated (dry) gas and sends it to the “Plinacro” transport system. The moisture-saturated TEG is directed to the regeneration unit.

TEG is regenerated using an exchanger and a TEG boiler (reboiler)*. This is also an accumulator of dry TEG and contains a stripping system that ensures the required TEG purity of min. 99.7% wt.

To comply with stringent emissions regulations, the system cools the vapor from the reboiler. Additional separation then extracts the remaining gas, which serves as fuel for the reboiler burner.

The production process

The unit is designed for two phases of production:
1st phase – extraction of part of the acquired gas reserves from the Grubišno Polje gas reservoir/field. (max. gas flow of 15,000 Sm3/h)
2nd phase – after the construction of the peak underground gas storage in the partially depleted Grubišno Polje gas field (max. gas flow 100,000 Sm3/h)

The manufactured unit is a “Croatian product”. It incorporates domestic knowledge and experience (know-how) with many installed pieces of equipment from Croatian manufacturers.

The planned installation of the unit is in the third quarter of 2022. The commissioning is arranged in the first quarter of 2023.

*Reboiler in which it is “boiled” until water vapor appears, separated from the TEG by gas stripping: