| |  | | | | Seawater Desalination |
| |  | | | Desalitech SWRO system | |
Desalitech offers complete, ultra-low energy, high recovery Seawater Reverse Osmosis (SWRO) units that reduce desalination costs by 20% or more.
Here is how Desalitech’s Closed Circuit Desalination (CCDTM) technology outperforms state-of-the-art conventional SWRO systems:
ü Record Low Energy Consumption – State-of-the-art SWRO processes operate at specific energy consumption levels of above 2.5 kilowatt-hours per cubic meter of permeate produced (kWh/m3). At the same recovery level (46%) and flux conditions (13 lmh = 8 gfd), Desalitech SWRO-CCD units consume less than 1.7 kWh/m3, thereby reducing energy consumption by 33%. Operation at less than 1.5 kWh/m3 is feasible at reasonable recovery and flux conditions.
ü High Flux – Alternately, the Desalitech SWRO-CCD unit described above can be tuned to operate at an increased flux of 24 lmh or higher to produce almost twice the amount of permeate with the same number of membranes, while energy consumption remains below 2 kWh/m3.
ü Maximum Recovery - State-of-the-art SWRO plants operate at recovery levels of about 42% in a seawater salinity of 35,000 milligrams per liter (mg/L) total dissolved solids (TDS). Desalitech system can increase seawater recovery to above 65%, limited only by the scaling characteristics of the source water and the maximum pressure rating of standard RO equipment. High recovery greatly contributes to the economy of an SWRO plant, reducing both the capital cost and the operation expenditures associated with pre-treatment and intake and brine rejection infrastructures.
The table below lists typical specific energy consumption levels, permeate production capacities and recovery rates for a Desalitech SWRO system with 48 membrane elements operating in 35,000 mg/L TDS seawater:
|
Production m3/day |
Flux
l/m2/h |
kWh/m3 at indicated recovery |
|
40% |
45% |
50% |
55% |
60% |
|
1,008 |
23.5 |
1.91 |
1.97 |
2.02 |
2.09 |
2.18 |
|
941 |
22.0 |
1.86 |
1.92 |
1.98 |
2.05 |
2.13 |
|
864 |
20.0 |
1.80 |
1.86 |
1.91 |
1.99 |
2.08 |
|
768 |
18.0 |
1.75 |
1.80 |
1.86 |
1.93 |
2.03 |
|
686 |
16.0 |
1.70 |
1.75 |
1.80 |
1.88 |
1.98 |
|
605 |
14.0 |
1.65 |
1.70 |
1.75 |
1.82 |
1.92 |
For comparison, a modern SWRO plant with the same number of membrane elements will typically produce 560 m3/day of permeate at a flux of 13 lmh and a recovery rate of 45% while consuming over 2.5 kWh/m3. Under these same conditions, a Desalitech system would consume less than 1.7 kWh/m3 or 33% less energy.
In many seawater desalination plants, a second pass is implemented to remove boron or other trace minerals from the product water. Desalitech's brackish water RO technology is of special value for second-pass applications, facilitating high recovery while maintaining extremely low energy consumption levels and equipment costs.
Click here to learn more about CCDTM technology.
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