A Portable and Battery-Powered Seawater Desalination Device by Ion Concentration Polarization

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1 A Portable and Battery-Powered Seawater Desalination Device by Ion Concentration Polarization Dr. Sung Jae Kim, Prof. Jongyoon Han November 16, 2010 Micro/Nanofluidic BioMEMS Group, Department of Electrical Engineering and Computer Science,

2 Water Resource on the Earth 2/12 World Water Development Report

3 Global Water Market Wastewater Sewage treatment Equipment for wastewater treatment Chemicals and services for the industry Membrane systems for wastewater treatment Drinking water Drinking water purification (Sales of bottled water) Ozone treatment UV treatment Treatment using membrane systems Desalination Thermal desalination plants Desalination plants with membrane Desalination plants running operation Market volume 2007 (USD bn) (91) Expected annual growth 19% (10%) 10% 14% 20% Source: Global water Intelligence: Global Water Market % 6% 4% 4% 4% 8% 9% 3/12

4 Fresh Water in Resource-Limited Setting 2.6 billion people do not use improved sanitation Disaster-stricken areas Brackish ground water Groundwater turns brackish Disaster relief, military and humanitarian operation Underdeveloped area Lack of delivery and on-grid infrastructures Worldwide use of improved sanitation facilities in WHO report /12

5 Conventional Seawater Desalination Reverse Osmosis Best energy efficiency ~ 5 Wh/L Requires large scale plants and significant membrane fouling Electro-Dialysis Less membrane fouling Worse energy efficient ~ 20 Wh/L Thermal distillation / freezing Easiest method Energetically costly 5/12

6 Competing Technologies Small/Medium scale desalination / purification system Household RO machine with UV lamps only for tap water like groundwater e.g. Aquaguard, GE profiletm (only for <2000ppm TDS source water) c.f. Brackish water: ppm TDS, Seawater: 30,000-40,000ppm TDS Medium-scale seawater desalination RO systems are not cost- and energy-efficient e.g. Ampac Seapro 100 (>$7650), 30-90Wh/L Other technologies focusing on particulate/organics, not salt e.g. spiral filtration system (PARC) chemical agent for inducing flocculation-sedimentation activated carbon filters Organism Examples General Size Filter Type Particle Size Rating Protozoa Giardia, Cryptosporidium 5 microns or larger Water filter microns Bacteria Cholera, E. coli, Salmonella microns Microfilter microns Viruses Hepatitis A, rotavirus, Norwalk virus microns Water purifier to microns 6/12

7 Micro/Nanofluidic Desalination Method 500 m Brine reservoir 100 m~1mm V + pressure seawater ANY charged species ion depletion boundary brine nanojunction V fresh water (50% recovery) V Fresh water reservoir 7/12 Nature Nanotechnology, 2010, 5, 297. US provisional patent, TLO case # / 13218,

8 Conductivity of Desalted Stream 50 Seawater (from Crane Beach, Ipswitch, MA) 40 ~500 mm Conductivity (ms/cm) Salt evenly distributed Partially desalted Completely desalted at low channel Applied electric field (V/cm) ~4 mm drinkable water: <10 mm Calculated power consumption ~ 3.5 Wh/L c.f.) RO ~ 5.0 Wh/L, ED ~ 20.0 Wh/L 8/12

9 Removal Capability scale 1Å 1nm 10nm 100nm 1 m 10 m 100 m atomic/ ionic low molecular high molecular micro particle macro particle solutes, particles ions DNA proteins bacteria E. coli hair hormones viruses clay particles RBC WBC separation process reverse osmosis electrodialysis nanofiltration ultrafiltration microfiltration micro/nanofluidic desalination / purification 9/12

10 Portable, Self-Powered System 1,600 unit devices on a 8 diameter plate ~100W solar panel With the massive parallelization, we can expect Total flow rate ~ 300mL/min (can supply 7 peoples basic need by 1hr) 3.5Wh/L can be supplied by photovoltaic cell (25mW/cm 2 ) or battery (~70W) Cost estimation of manufacturing 1 stack ~$500 including materials and machine fees, excluding labor and software 10/12

11 Competition Cost: ICP vs. RO 60k 50k Cost (USD) 40k 30k 20k ICP system production and setup costs per device 100 wafers / month 500 wafers / month Energy Costs Maintenance Costs Total costs of RO for consumer 10k 5k Investment Costs Water production rate (liter/hour) Courtesy by iteam project member at MIT 11/12

12 Where can it be applied for? ICP desalination Phase I, (2yrs) Individual use Shipboard application Disaster relief Recreational purpose Military / humanitarian use Flow rate ~ 100mL/min Cost-insensitive application Should be easy of use High energy efficiency Phase II, (1yr) Community use Large ships Rural areas Island communities Flow rate ~ 1L/min Cost-sensitive application Should be easy of use High energy efficiency Phase III, (2yrs) Large-volume Apps Large scale desal plants based on ICP desalination Pre-treatment for large-scale existing desal plants Rare metal mining from seawater / groundwater Flow rate >> 1L/min Cost-sensitive application Should be easy of use High energy efficiency 12/12

13 One tiny gap in a channel, One giant leap for better life Questions? 13/12 Research Laboratory greenhelm.spyestate.com of Electronics