Unlocking more capacity from the same desalination plant

To meet the increasing demand for water, coastal cities and industries are increasingly turning to seawater desalination. Expanding a desalination plant’s capacity often means constructing what can be considered as a completely new plant – besides additional water treatment systems, the scope can include massive civil works such as a new intake and outfall structure. High capital costs and lengthy permitting processes become unavoidable.

With today’s ultra-high pressure reverse osmosis (UHPRO) systems, it has become increasingly economically viable to upgrade an existing seawater desalination plant with UHPRO, offering lower capital expenditure and faster deployment.

In this article, De Nora’s senior process engineer, Ghazi Ozair and Gerald Richard Ross Sisniega, Sales Director for Latin America, share more about De Nora’s UHPRO Brine Positive, which is designed to recover approximately 22% more desalinated water from the same volume of seawater.

UHPRO refers to reverse osmosis systems which operate at high pressures, such as at 1740 PSI (120 bar), compared to the conventional 1200 PSI (83 bar).

UHPRO systems enable higher recovery rates and greater brine concentration.

• With brine concentrate from UHPRO at about two times the typical concentrate values, the recovery of some precious metals and minerals can become a viable option.

• The lower volume of brine discharge facilitates the goal of Zero Liquid Discharge (ZLD) with higher efficiency.

In a typical seawater reverse osmosis (SWRO) desalination plant, assuming a SWRO recovery rate of 45%, 55% of the volume entering the SWRO is discharged as brine.
With the addition of a UHPRO pass after the first pass SWRO, the brine discharge is reused as feedwater for the UHPRO pass. Assuming a recovery rate of 40% from De Nora’s UHPRO Brine Positive solution, an additional 22% of desalinated water can be recovered.

Figure 1: An example of a typical seawater desalination plant.

Figure 2: An example of a seawater desalination plant with De Nora’s UHPRO Brine Positive

“As water demand outpaces supply, there is growing interest in UHPRO Brine Positive. As compared to new builds, it is faster to implement, and a reliable lower-risk solution to unlock more water from existing plants,” says Gerald.

“When paired with current membrane innovations, UHPRO provides a practical pathway to treat hypersaline brines—from seawater reverse osmosis or thermal desalination, to industries such as semiconductors, mining, and pharmaceuticals, while enabling higher recovery,” says Ghazi.