Forward Osmosis Applications for the Power Industry

Transcription

1 Forward Osmosis Applications for the Power Industry American Filtration Society 2015 Spring Conference Charlotte, North Carolina Bill Harvey Director of Strategy and Business Development Providing world-leading water technologies April 2015

2 Modern Water - Summary Listed on London Stock Exchange AIM Market Based in UK, with Global Customers and Offices Two Divisions: Membrane Process and Monitoring

3 FO Applications Key Applications Desalination Evaporative Cooling Enhanced Oil Recovery Thermal Desalination Feedwater Softening Fracture Water Treatment Industrial Process Concentration/Dilution Other Opportunities Hydro Osmotic Power Sewer Mining Leachate Treatment

4 Forward Osmosis π π π

5 Forward Osmosis

6 FO Modules Membrane Materials CTA TFC Others in development Courtesy: HTI Form Factor Plate and frame Spiral-wound Hollow fiber Courtesy: Porifera Membranes must be thin so feed stream sees OA stream for water transfer to occur.

7 Configuring the Driving Force: Osmotic Agent Design Levers: Concentration of OA Compatibility Cross-flow velocity OA Types Typically inorganics: NaCl, NaSO 4 et al Striking the Balance: Osmotic Pressure (concentration & chemistry) OA Recovery Energy

8 FO Applications Dehydration Dewater high value fluids, e.g. fruit juice Avoid change in taste due to thermal methods Operate above allowable RO concentration Membrane Filtration Replaces UF as RO pretreatment, similar capex and opex Finer filtration Convert RO feed chemistry to a more desirable type (monovalent cations) Membrane Brine Concentration Concentrate high TDS water much higher than conventional RO Up to 130,000 mg/l with electricity Higher with thermal methods

9 Forward Osmosis for Desalination

10 Forward Osmosis Desalination Seawater or brackish water feed Reject from manipulated osmosis system Manipulated Osmosis System Diluted Osmotic Agent Concentrated Osmotic Agent Regeneration Membranes Product Water

11 EVALUATION CONDITIONS Case A Case B Case C Desalination process FO + RO Single Pass RO Two Pass RO Throughput (m 3 /day) 50,000 50,000 50,000 Feed TDS 1 (mg/l NaCl) 35,000 35,000 35,000 Feed Temperature ( o C) Pre-treatment Processes (process loss %) Intake Screens (0%) Media Filtration (5%) Cartridge Filters (0%) Intake Screens (0%) Media Filtration (5%) Ultrafiltration (5%) Intake Screens (0%) Media Filtration (5%) Ultrafiltration (5%) FO Recovery 40% NA NA RO Recovery 40% 40% 37.5% Energy Recovery Device Pressure Exchanger Pressure Exchanger Pressure Exchanger IFOA Conference

12 Desalination Cost of Water Cost of Water, ($/m 3 ) $1.10 $1.00 $0.90 $0.80 $0.70 $0.60 $0.50 $0.40 $0.30 $0.20 $0.10 $0.00 FO + RO UF + RO (single pass) UF+ RO (two pass) Supervision & Labour $0.03 $0.03 $0.03 Maintenance & Parts $0.07 $0.07 $0.07 Chemicals $0.05 $0.05 $0.05 Membranes $0.05 $0.05 $0.06 Power $0.27 $0.25 $0.32 Capital Amortisation $0.47 $0.47 $0.49 IFOA Conference 18 19

13 Forward Osmosis for Evaporative Cooling

14 Drivers for Evaporative Cooling Environmental damage from once through cooling Low carbon alternative to refrigerated cooling Qatar Thermal discharge maximum increase 3ºC for once through cooling (high seawater flows required) UAE Mains potable water not supplied to new district cooling plants California elimination of once through cooling due to concerns over intakes

15 Evaporative Cooling water supply Desalinated water Reverse osmosis Thermal desalination FO desalination Evaporative cooling make-up water Mains potable water Dedicated RO plant Treated Sewage Effluent Seawater Forward osmosis

16 Conventional Cooling Tower Drift Loss Evaporation Cooling Tower Make-up Heat Exchanger Chiller Plant Blowdown Recirculation Pumps

17 FO Cooling Tower System Cooling System incorporating FO make-up Osmotic agent in CT loop Make-up via forward osmosis

18 FO Cooling Tower System Cooling System incorporating FO make-up Osmotic agent in CT loop Make-up via forward osmosis

19 Osmotic Agent / Cooling Water Osmotic agent low cost Readily available and non toxic Osmotic agent concentration optimised for raw water feed to minimise losses Corrosivity testss of FO agent Pilot at Oman industrial site 304 ss, 316 ss, Cu alloys little or no metal loss Carbon steel some metal loss, greatly reduced by corrosion inhibitor (phosphonates & carboxylic acid) Pilot FO + Cooling Tower available for demonstration Legionella (source CDCP)

20 Osmotic Agent / Cooling Water h Biological testing Legionella killed in osmotic agent MIC 3.6 bar equivalent Pseudomonas not inhibited Blowdown reclaim system Loose membrane based Retains osmotic agent and chemical additives Average counts of Lp (CFU/ml n=3) h 72 h Equivalent Osmotic Pressure (bar)

21 Power Comparison Make-up Water kwh/m RO with ERT RO no ERT Manipulated Osmosis Manipulated Osmosis (OA recovery) 0 10,000 20,000 30,000 40,000 50,000 Feed Water TDS (mg/l) Assumptions Temperature 25ºC Maximum conversion on MO limited to 30% (very conservative) Pre-treatment requirements the same for MO and RO Conversion for RO, 80% - 41% depending on feed TDS Pump overall efficiency 70% Tower concentration ratio 5 Energy recovery efficiency 70%

22 Evaporative Cooling FO Advantages Same platform technology as desalination Can utilise a wide range of feedwaters Significantly reduced power consumption compared with reverse osmosis (88% - 40%, typically 50%) Reduced CAPEX, compared to seawater RO Extensive use of low cost plastic materials with FO Low fouling propensity of forward osmosis process Cooling water additives are retained by the blowdown recovery system Can be retrofitted to existing installations Offers an economic alternative to potable water or TSE A disruptive technology significantly lowering costs and extending applicability of evaporative cooling

23 THE FUTURE Desalination Costs FO Membrane Cost / Output IFOA Conference

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