Nitrogen puffing can prevent salt buildup in centrifuges

Salt settlement can impact the efficiency of centrifuge equipment. However, a viable solution to prevent this issue is nitrogen puffing, write Turki Alghamdi, Khaled Aljuhany and Pietro Scoppetta from Saudi Aramco in their research

- Khaled Aljuhany

MONOETHYLENE Glycol (MEG) is widely used as a dehydration agent in the natural gas industry. In the MEG regeneration process, centrifuge equipment is commonly used to separate salts from the MEG solution.

However, salts settlement can cause significant issues with the efficiency of the centrifuge equipment.

The MEG regeneration process involves several steps aimed at obtaining lean MEG form the rich MEG stream.

Rich MEG is typically received in the MEG regeneration unit from the plant slug catchers and inlet separators. This liquid feed generally contains some dissolved hydrocarbons, CO2, salts and solids.

Filtration removes solid particles and floating impurities from the MEG solution. Degassing and thermal processes leave a stream with concentrated salts.

The separation of the salts from the MEG solution is usually referred to as reclamation. The slurry stream produced in the reclamation is typically fed to a centrifuge to produce a salt cake.

“Centrifugation is the most efficient method for separating salts and impurities from the MEG solution during the regeneration process and is included to enhance the level of recovery of glycol,” a research study by Turki Alghamdi, Planning and Performance Management Analyst, Saudi Aramco, Khaled Aljuhany, Project Engineer, Saudi Aramco, and Pietro Scoppetta shows.

CENTRIFUGATION

During centrifugation, centrifugal force is applied to the slurry that has been obtained by processing of the contaminated MEG solution, causing heavier particles to separate and settle at the bottom of the equipment.

The purified MEG is then recovered along with the regenerated MEG, leaving the separated impurities to be removed later.