Desal URN test

Seawater Desalination Research p y j Energy consumption of various system capacities Treatment Step ADC MAP 0.3 mgd(2) 10 mgd(2) 50 mgd(2) RO Process 7.8 / 2.06 (1) 10.6 / 2.80 9.1 / 2.40 8.0 / 2.11 Intake (2) 2.17 / 0.57 2.01 / 0.53 1.74 / 0.46 1.72 / 0.45 Pre-filtration (2) 1.14 / 0.30 1.05 / 0.28 0.91 / 0.24 0.90 / 0.24 Permeate treatment (2) 0.25 / 0.07 0.23 / 0.06 0.17 / 0.04 0.16 / 0.04 Permeate distribution (2) 1.27 / 0.33 1.17 / 0.31 0.86 / 0.23 0.85 / 0.22 Total Treatment 12.6 / 3.33 15.1 / 3.99 12.8 / 3.38 11.6 / 3.06 1. MAP average value from the 4 membrane sets that met MAP water quality goals of <200 mg/l TDS and <1.045 mg/l Boron. 2. Projected values based on typical parameters and conditions. 3. kWh/kgal / kWh/m3 • Table 6. ADC Power Consumption and System Projections Figure 7. Costs vs Flux at 50% Recovery - 50 MGD SWRO WTP $/m3 3.17 $/kgal 3.50 2.91 3.25 $/gpd $/m3/day 10.00 2,642 Poly. (SWSWC5 Capitol) Poly. (SW30HR-380 O&M) 9.00 2,378 Poly. (SW30XLE-400i O&M ) Poly. (SW30HRLE-400i O&M) Total Treatment Costs 2.64 3.00 2.38 2.75 7.00 1,849 2.11 2.50 1.85 2.25 Poly. (SWC5 O&M) 8.00 2,114 Poly. (ISD Hybrid O&M) Poly. (SW30HR-380 Total) Capitol Costs Poly. (SW30XLE-400i Total) 6.00 1,585 Poly. (SW30HRLE-400i Total) 5.00 1,321 O&M Costs 1.58 2.00 4.00 1,057 1.32 1.75 3.00 1.50 2.00 1.25 1.00 1.00 Poly. (ISD Hybrid Total) Poly. (TM800E-400 Total) 264 1.06 Poly. (SWC5 Total) 528 1.06 Poly. ("TFC 2822HF-400 Total) 792 1.06 • 0.00 5 6 7 8 9 10 • 11 Desalination & Water Reuse Vol. 18/2 RO flux rate (gfd) 38 • Poly. (TFC 2822HF-400 O&M) Capital costs O&M and Treatment Costs Poly. (TM800E-400 O&M) 70% efficient intake and prefiltration pumps to be 15.1 kWh/kgal (3.99 kWh/m3). By contrast, the 50 MGD projections use an efficiency of 88% for the main high-pressure pump and 80% for the intake and prefiltration pumps. In addition, the motors and control systems are generally more efficient for the largest systems resulting in a total treatment power of 11.6 kWh/kgal (3.06 kWh/m3). Figure 8 provides a graphical view of how the energy consumption of a system will vary with size. The largest systems have the potential to be even a more efficient than the ADC pilot because they can employ more efficient motors and control systems. Process Variables System capacity, mgd RO feed pressure, psi / bar Flux, gfd RO recovery, % Permeate quality, TDS Permeate Boron, mg/l Raw water, TDS Raw water temperature, ºF / ºC Table 7 provides figures on the associated key system parameters and performance from the ADC pilot with these values also projected over various system capacities. According to the ADC's 50 mgd net present value model, the projected cost of water over the 4 MAP's ranged from $2.90-3.00/kgal ($0.77-$0.79/m3) with an average of $2.95/kgal ($0.78/m3). CONCLUSIONS The following results and conclusions can be made from the ADC's demonstration study data and a conceptual 50 mgd SWRO facility: • Testing was performed consecutively and was not conducted as a side-by- ADC MAP Average 0.08 914 / 63 9.0 48% 119 0.7 35,640 60 / 15.5 Projections 0.3-50 914 / 63 9.0 48% 119 0.7 35,640 60 / 15.5 Table 7. ADC Operating Parameters and Performance © 2008 FAVERSHAM HOUSE GROUP side evaluation. Therefore the results should not be used to make direct performance comparisons of the manufacturers' membranes. The results provide a bench mark for SWRO energy consumption in Southern California. According to the performance data and NPV estimates, higher recovery consistently resulted in a projected lower total cost of water. Furthermore, the trend showed that costs could be reduced further by operating at higher recoveries than those tested in the ADC protocol. Though the RO specific power generally increases with recovery rate, the total energy required for treatment decreases with increasing recovery. This is due to the increased volume of raw feed water that must be pumped and treated at lower recovery rates to obtain the same volume of permeate. According to the performance data when analyzed by the NPV model, flux variations from 6-10 gfd were estimated to result in almost no change in the total treatment costs. Higher flux produced better water quality and it was estimated to have little effect on the total treatment costs. The ADC has been able to demonstrate energy consumption for seawater desalination at levels of 10.4 to 11.3 kWh/kgal (2.75-2.98 kWh/m3) at a projected total cost of $2.83-3.00/kgal ($0.75-$0.79/m3). These energy levels and cost figures are comparable to other traditional sources. For example, in Southern California, the State Water Project, which transports water from Northern California to Southern California, consumes on average 10.4 kWh/kgal (2.75 kWh/m3) . And in San Diego, California, end-users can pay more than $6.00/kgal ($1.58/m3) . Therefore, Southern Californian seawater desalination is an affordable and reliable new source of high quality fresh water. FUTURE STUDIES In the future the ADC will be demonstrating new flow schemes to help increase the achievable recoveries of today's system using off-the-shelf components. In addition, the ADC plans

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