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Development of an Integrated Power Delivery Electrodialysis Desalination System!!

VARUN SHANKER AUSTEN ZHU SATYAJIT SARKAR MADISON KENT ANDREW WONG

DOW HIGH ELECTRODIALYSIS DESALINATION SYSTEM

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Table!of!Contents!

Executive)Summary)................................................................................................................)3!Project)Overview)..............................................................................................................................)3!Impact)of)External)Factors)................................................................................................................)4!Description)of)Innovation).................................................................................................................)5!Global)Benefit)..................................................................................................................................)6!

Statement)of)Work).................................................................................................................)7!Wooden)Experimental)Cell)...............................................................................................................)7!Plastic)Batch)Cell)with)Flow)..............................................................................................................)9!Plastic)Batch)Cell)Testing)................................................................................................................)11!Data)Analysis).................................................................................................................................)19!Early)Prototype)of)Integrated)Power)Delivery)Electrodialysis)Desalination)System)(IPDEDS))..........)20!Market)Plan)...................................................................................................................................)23!

Research)and)Explanation)of)Existing)Technology)..................................................................)28!

Financial)Plan)........................................................................................................................)32!Funding)..........................................................................................................................................)34!

Project)Management)&)Timeline)...........................................................................................)38!

Graphical)Representation)......................................................................................................)39!

Appendix)A)............................................................................................................................)43!

References)............................................................................................................................)49!!

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Executive!Summary!Project!Overview!!

As the global population continues to rise and sources of freshwater become increasingly

depleted, water purification and desalination technologies are emerging as the most prominent

method to meet this fundamental need. The most rapidly growing approach to converting

saltwater to drinkable water is reverse osmosis, a method of desalination that removes water

molecules from salt water through pressure, leaving salt ions in a residual brine. However, more

cost-effective and sustainable alternatives such as electrochemical desalination are being

developed.

Electrochemical desalination processes exhibit the greatest future potential to meet the

worlds potable water needs. An electrochemical cell (schematic shown below) is a device that

utilizes electrical energy in order to facilitate chemical reactions. This technology can be applied

more specifically to desalination through electrodialysis: a membrane process, in which ions are

transported through a selectively semi-permeable membrane, under the influence of an electric

potential. The Dow High Team utilized and created advanced technologies developed an

innovative, low-cost, efficient, energy- independent electrodialysis system functioning to

desalinate brackish and ocean water, thereby producing pure, potable water.

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!Through the product development process and scientific experimentation, the Dow High

team was successfully able to design, engineer, construct, and test and prove the innovative

electrodialysis method of desalination. Product development began by machining the structure of

the construct from chemically inert polypropylene plastic and continued into assembly of the

piping, tubing, and smaller hardware components. The final construct was experimentally tested

in numerous trials to ensure statistically robust and reliable data.

The Dow High electrodialysis cell has proven to be effective at removing salt from

simulated seawater samples. The complete model development is highly scalable, requires lower

infrastructure investment than reverse osmosis and other competing technologies, and is highly

energy efficient as salt concentrations approach brackish water levels. Designed to be energy-

independent, the electrodialysis system is powered by a photovoltaic cell (solar panel).

Impact!of!External!Factors!! Efficiently designed electrodialysis systems have a unique comparative advantage to

alternate methods of water conversion and desalination by mitigating and minimizing the impact

of uncontrollable external factors. Unlike other methods of desalination such as distillation and

the solar still, the electrodialysis system is able to function independent of the weather and

climate conditions. The only external input required is electricity. The design of the

electrodialysis system allows for convenient interchange of power supply. Most encouragingly,

the energy required to supply the system is minimal, easily generated by photovoltaic cells, and

can be stored in a battery enabling the cell to operate at night and on cloudy days. Depending on

the area of use, the power supplying photovoltaic cells can be substituted with other sources of

alternative energy such as Peltier tiles, which function by converting thermal gradients into

electrical energy.

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One key advantage of the electrodialysis system is its lack of dependency on the

concentration and form of salt water. It was demonstrated, without fail, through numerous trials

that the electrodialysis system performs efficiently at removing salt from ocean and brackish

water at both high and low concentrations of salt. Additionally, the Dow High teams

electrodialysis system has a unique comparative advantage to alternate forms of water

conversion in dually functioning to kill biological organisms and pathogens that may be present

in the salt water.

Description!of!Innovation!!

The integrated power delivery electrodialysis desalination system (IPDEDS) engineered

by the Dow High team is a unique combination of advanced technologies that meets a basic need

in broad applications. The complete desalination system is the integration of an independent

power source fueled by renewable energy with a uniquely designed robust and low maintenance

electrodialysis cell, based on sound fundamental scientific principles. The electrodialysis cell,

which incorporates hybrid membrane technology, was completely machined and assembled from

stock plastic and hardware components into a reliable and compact desalination device.

Consistently shown to desalinate saltwater with concentrations similar to ocean and brackish

water (upwards of 35g/L of salt in scientific experimentations) the electrodialysis cell

incorporated in the innovative IPDEDS proved to be more robust, cost-effective and sustainable

than competing methods of water conversion. While other systems of desalination such as

reverse osmosis and distillation have been used in large scale implementations, the portable

electrodialysis system proves to be far more economical and convenient for its target markets. At

the center of this innovative the electrodialysis system lies its unique value proposition. In

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addition to offering portability and high efficiency, the system is easily scaled up in a modular

fashion, and is thereby able to increase total output at a marginal additional cost.

Global!Benefit!! Although water scarcity can be an abstract concept, to many it is truly a stark reality an

outcome of environmental, economic, and, geographic forces. While water constitutes 70 percent

of the world's surface, only 2.5% of it is freshwater, leaving the remainder as saline and ocean-

based. Moreover, 99% of this freshwater is in unusable forms such as snowfields and glaciers.

Simply put, 0.007% of the earth's water is accessible to meet the drastically increasing rate of

consumption of the world's seven-plus billion individuals. It is imperative to consider the

development of new water desalination technologies to accommodate the populations needs.!

The IPDEDS is applicable to coastal communities of developing countries, military needs

and emergency situations. It is estimated that by 2025, over 1.8 billion people will be living in

water stressed regions. As a result, the independently powered electrodialysis system is capable

of providing a broad and prominent global impact. In a remote area, military troops can hydrate

themselves while traveling with the system. In coastal water stressed areas After a hurricane or

an earthquake strikes a coastal town contaminating its freshwater reserves, individuals will be

able to quickly desalinate highly concentrated saltwater to produce potable water. IPDEDS has

the potential to be a game-changing system that fulfills the need for water in such situations.

This innovative desalination system has the potential to revolutionize the water

purification and desalination industry and, in effect, provide widespread global impact benefiting

millions.!

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Statement!of!Work!!

The team decided to focus on creating a device that could provide a reliable, modular and

portable, low cost, source of clean, sanitary water from sea water or other brackish water

sources. After initial research, the process of electrodialysis was chosen as the method of

desalination. Several intermediary goals were created. Chiefly, a robust electrodialysis cell

design was needed. Secondly, the team needed to prove that electrodialysis could be used on a

smaller, more portable scale. Finally, in order to create a product that would be relevant in

power-deprived areas, the team decided that alternative energy sources should power the

desalination process. The prototype would incorporate the electrodialysis cell design, alternative

energy resources in the form of solar panels, an organized system of piping and wiring, and a

plastic casing for portability.

Wooden!Experimental!Cell!!!

Initially, the team decided to create a wooden batch cell. A batch cell desalinates a

batch, or fixed amount, of salt water until purification. In comparison, a flow cell continuously

processes and dilutes new salt water. This initial design consisted of a 8.5 x 8.5 x 9.5 cell with

an open top. 1 thick plywood was sourced from the schools woodshop for construction, leaving

a 6.5 x 6.5 x 8.5 space for the salt water. This space was then separated into 3 chambers, each

2.166 x 6.5 x 8.5. Along the divisions between each of these chambers, cavities were cut into

the wood to accommodate the needed membranes. In order to fix the membranes within these

cavities, a square hole of 5.5 x 5.5 would be cut from 7 x 7 plastic acrylic sheets. Two of

these frames would sandwich the 6 x 6 membrane, allowing the membrane to be exposed to

salt water through the inner opening. The space between each plastic frame-membrane construct

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was sealed with silicone sealant. The wooden joints were also sealed with the same sealant. Two

square 5 x 5 copper sheets were to be attached with epoxy onto the inside of the end pieces in

both the left and right chambers. The copper electrodes were to have a copper wire soldered onto

them to power the electrodialysis process.

For testing, these wires would have been connected to a power supply. A logger pro

voltage probe would have been attached to the two copper wires. Additionally, a salinity probe

would have been placed inside the center chamber (the product chamber).

However, as expected, a variety of issues were identified from this early prototype.

During the desalination process, dilute water is formed as a thin layer of water close to the

membranes in the product chamber. Because the water within this design does not circulate, the

water would not be homogenously desalinated thus requiring a mixing mechanism. Additionally,

because of this lack of flow within the cell, the anolyte (the portion of the electrolyte in the

immediate vicinity of the anode in an electrolytic cell)!and catholyte (the portion of the

electrolyte in the immediate vicinity of the cathode in an electrolytic cell) become extremely

concentrated with byproduct, creating a potentially potent solution. Using wood as the material

of the container also presented a major issue- it would absorb water and thus lose dimensional

Wooden&Experimental&Cell&with&Plastic&Frame&inside&

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robustness and strength. As a result of this evaluation of the initial prototype design, the team

proceeded to design a secondary construct featuring external chambers allowing for mass

transport of solutions.

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Plastic!Batch!Cell!with!Flow!!!

The revised design addressed the two primary concerns: excessive volume (distance)

between the ion exchange membranes and lack of flow in all three chambers of the batch cell.

Additionally, polypropylene which is a commodity lightweight and chemically inert

thermoplastic was chosen to address the absorption issues.

Two polypropylene pieces of 7 x 7 x 1 were used as stock for the outer anolyte and

catholyte chambers. An inset square of 5.5 x 5.5 was milled out of the stock deep, resulting

in a fluid compartment (chamber) of 5.5 x 5.5 x .75.

In order to house the membranes, four 7 x 7 rubber gaskets were used. Each rubber

gasket had a 5.5 x 5.5 square inset cut out. A 7 x 7 ionic exchange membrane was then

placed in between two rubber gaskets. This was repeated twice, once for the anionic and once for

the cationic membrane.

A polypropylene piece of 7 x 7 x was used as the inner product chamber. The same

5.5 x 5.5 square inset was cut out of this polypropylene piece.

The cell is built as a stack. Construction begins with an outer chamber. A 5 x 5

electrode is placed within the milled cavity of this chamber. A membrane framed by two rubber

gaskets is placed on top. Next, the inner chamber is placed on the developing stack. Another

rubber gasket-membrane frame is added. Finally, the second outer chamber is added with a 5 x

5 electrode, finishing the stack.

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Coincident holes were punched into the membranes, the chambers, and the rubber

gaskets. In order to fix the stack together, it was compressed with a combination of screws and

washers. Using a drill press, twelve holes were drilled along the border of the plastic pieces

in the external and internal polypropylene plastic. Using the drill pressed holes, coinciding holes

were punched through the membranes, ensuring that the holes were flush. These holes were used

to secure #10 machine screws which are purposed to hold the entire cell construct together.

Subsequently, a hole was drilled through the center of the outer chambers to

accommodate a quarter inch fitting to fit 8-gauge wire. The hole was tapped and a fitting was

threaded in with Teflon tape. The 8-gauge was soldered to a copper electrode on the open end of

the outer chamber and hooked to a positive/negative lead on a power supply on the other.

The final machining was the creation of two distinct holes for the pumps to provide water

flow in each chamber. For the inner product chamber, the piece was clamped upright on a

drill press bench with one of the inch thick edges facing down. A 3/32 hole was drilled

straight down the center of the top thick face, deep. Then, a hole 1/8 in diameter was

Outer&Chamber& Inner&Chamber&

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drilled in the same location approximately 3/8 deep. This was the hole for the inflow tube. This

process was repeated on the opposite face to create the outflow tube. For the outer chambers, the

inflow and outflow were two holes that were drilled 3/2 from the center electrode hole towards

opposite diagonals. The holes accommodate fittings for polyethylene tubing. These holes

were also tapped for the proper threading and the fittings were threaded in with Teflon tape.

The first finished assembly of the cell consisted of an outer chamber, a copper cathode

flush against the chamber, rubber gasket, anion exchange membrane, rubber gasket, the product

chamber, a rubber gasket, cation exchange membrane, a rubber gasket, a copper anode, and a

final outer chamber respectively.

Plastic!Batch!Cell!Testing!!Proper scientific experimentation was used to determine the functionality and performance of the

electrodialysis cell. Salt solution at 35 parts per thousand was used as the testing solution in

order to simulate the salinity of ocean water. Thus, the resulting final salinity upon completion of

desalination is a reliable indicator of the cells performance with ocean water. An uninterrupted

Cell&Assembly&Creating&the&holes&with&Drill&Press

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power source (UPS) was connected to the electrodes of the electrodialysis cell in order to

provide current. The resulting voltage, which changed in response to the varying internal

resistance of the cell, was monitored using a multimeter. As the current was supplied to the cell,

both salinity and voltage readings were logged as a function of time on a Vernier Logger Pro.

Readings were taken every two seconds until the salinity of the product water reached 0.0 parts

per thousand.

Experimental Setup

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1st Trial: The power supply was set to 2 Ampere-hours (Ah). Each external chamber was filled

with 600 mL of 35 ppt salt water. The experiment was allowed to run for 10 hours.

Note: A 30-point moving average is used to smooth out the data in each trial.

Results: The salt water reached 0.0 ppt salinity after 6.5 hrs. Voltage data was not collected

properly because the logger pros voltage clips are maxed at 10 V. To get around this max

voltage reading, a series of resistors was attached to the clips, scaling the logger pros voltage

,5.0

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

0.0000 2.0000 4.0000 6.0000 8.0000 10.0000 12.0000

Salin

ity!(p

pt)

Time!(hrs)

Electrodialysis!Cell!Trial!1

Salinity!(ppt)

,5

0

5

10

15

20

25

30

35

0.0000 2.0000 4.0000 6.0000 8.0000 10.0000 12.0000

Salin

ity!(p

pt)

Time!(hrs)

Trial!1!30,Point!Moving!Average!

Salinity!(ppt)

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readings down by a scale of 0.325. The corrosion of the copper electrodes also became a

problem. Because copper is fairly reactive, the copper electrodes were corroded by the HCl

produced as a byproduct of the electrodialysis reaction. Therefore, they would be unable to go

through the desalination process a second time.

As a result, these copper electrodes were replaced by 304 stainless steel electrodes.

Coated with chromium, this metal is much less reactive making it less susceptible to corrosion.

2nd Trial: The power supplied was increased from an initial 2 Ah to 5 Ah by the end of the trial.

600 mLs of 35 ppt salt water was placed in each external compartment to begin the trial. The

experiment was allowed to run for 3.75 hours.

Copper&Electrodes& Copper&Electrodes&Corroded&304&Stainless&Steel&Electrodes

,5

0

5

10

15

20

25

30

35

40

0 0.5 1 1.5 2 2.5 3 3.5 4

Time!(hrs)

Electrodialysis!Cell!Trial!2

Salinity!(ppt)

Voltage!(V)

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Note: The voltage data has been multiplied by a factor of 2.333 to account for the series of

resistors.

Results: The salt water reached a purified 0.0 ppt after 3.75 hrs. However, because the power

supplied was increased as the trial continued, the data provided could not yield an accurate

voltage data. More trials were required in order to determine voltage curve at a constant Ah.

3rd 5th Trials: These experiments were run at 5Ah with 500 mL, 35 ppt salt water in each of the

chambers. The primary goal of these trials was to determine a voltage curve. This voltage curve

was used in the programming of the Arduino in the final model. Trial 4 had 600mL.

05

10152025303540

0 0.5 1 1.5 2 2.5 3 3.5 4

Time!(hrs)

Trial!230,Point!Moving!Average

Salinity!(ppt)

Voltage!(V)

0

10

20

30

40

50

60

70

0 0.5 1 1.5 2 2.5 3

Time!(hrs)

Electrodialysis!Trial!3:!5!Ah!

Salinity!(ppt)

Voltage!(V)

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3rd Trial Results: The salt water reached a salinity of 0.0 ppt after 2.5 hrs. 450 mL of this water

were recovered for a 90% product efficiency. The graph experiences a few spikes due a probe

being out of place handling the probes caused a fluctuation in readings.

0

10

20

30

40

50

60

0 0.5 1 1.5 2 2.5 3

Time!(hrs)

Trial!330,Point!Moving!Average

Salinity!(ppt)

Voltage!(V)

,5

0

5

10

15

20

25

30

35

0 0.5 1 1.5 2 2.5

Time!(hrs)

Electrodialysis!Trial!4:!5!Ah

Salinity!(ppt)

Voltage!(V)

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4th Trial Results: This trial was allowed to run for 12 hours. The graph reflects a focused portion

of the data. The salt water reached a salinity of 0.0 ppt after 2.5 hours. Approximately 550 mL

were recovered, yielding a 92% product efficiency.

,5

0

5

10

15

20

25

30

35

0 0.5 1 1.5 2 2.5Time!(hrs)

Trial!4!30,Point!Moving!Average

Salinity!(ppt)

Voltage!(V)

,5

0

5

10

15

20

25

30

35

40

0 0.5 1 1.5 2 2.5 3Time!(hrs)

Electrodialysis!Trial!5:!5!Ah

Salinity!(ppt)

Voltage!(V)

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5th Trial Results: The salt water reached a salinity of 0.0 ppt after slightly over 2.5 hours.

Approximately 500 mL of this purified water were recovered, achieving a 100% product

efficiency.

,5

0

5

10

15

20

25

30

35

0 0.5 1 1.5 2 2.5 3

Time!(hrs)

Trial!530,Point!Moving!Average

Salinity!(ppt)

Voltage

2.457777778,!30.67814754

0

5

10

15

20

25

30

35

0 0.5 1 1.5 2 2.5 3

Time!(hrs)

Average!Voltage!Curve!5!AhTrials!3,5

Voltage!(V)

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Clear&Purified&Water&from&Trials&1,&5,&3&respectively& & Purified&Water&from&all&trials&2,&1,&5,&3,&4&respectively&&

Data!Analysis!!

As observed in the above images, the purified water from trial 2 is slightly yellow. In this

trial 2, the cell continued to run after the salinity reached 0.0 ppt. The yellow discoloration could

be a result of the cell continuing to function when Na+ ions are scarce, electrodialysis shows a

preference for transporting Fe3+ ions. In this case, after complete desalination of the salt water,

electrodialysis begins to transport the Fe within the stainless steel electrodes, transporting it

across both membranes, discoloring the purified water. As iron mixed in water is harmless to the

human body, water with the Fe3+ is still consumable. However, to combat this problem, the team

decided to control the power supply with an Arduino, preventing water discoloration as a result

of electrodialysis.

The experimental data revealed that the electrodialysis system consistently and

without fail removed all of the salt from the salt water as the solution within the product

chamber reached a salinity of 0.0 ppt. However, additional data analysis was required to

program the Arduino, which needed to shut the power supply to the cell as the salt water reached

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a salinity of 0.0 ppt. At 5 Ah, the cell fully desalinated the salt water after 2.476 hours. The 5Ah

voltage curve also reached an upper limit of 30.678 volts. This data was used to program the

Arduino to control the supply of power to the cell in the final model.

Early!Prototype!of!Integrated!Power!Delivery!Electrodialysis!Desalination!System!(IPDEDS)!!

The final model was designed to incorporate the original electrodialysis cell design, solar

panels, and a plastic case for portability, producing a fully power independent desalination

system.

The team built an early prototype of this final design. Three circular containers formed

the external chambers for the salt water. Each container is placed tangent to the others, forming a

shape loosely resembling a triangle. On top of each of these three containers is piping that

connects to a cross fitting. An inlet tube extends from the cross fitting to a funnel.

In the final model, the electrodialysis cell lies horizontally, with the electrode wire

pointing upwards, below these three containers, separated by a series of rubber stoppers. This

electrode wire is in empty space formed by the three circular containers. Rubber stoppers are

located on the side of the cell facing the ground, propping it up so that the electrode wire does

not touch the ground.

Insulated wiring connects the electrodes to a voltage regulator. This voltage regulator is

then connected by more wiring to a battery. The battery has a capacity of 15000 mAh (=15 Ah),

with a max voltage of 12V. The voltage regulator allows the 12 V battery to power a cell that hits

upwards of 30V. As the cell desalinates the salt water, the voltage returned to the battery from

the cell increases. However, the voltage regulator ensures the battery receives a constant voltage,

ensuring the flow of power.

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The battery is then connected to an Arduino (a programmable micro-controller) for

control. The Arduino is connected to a voltage sensor that is connected to the two electrodes. The

Arduino receives voltage readings in order to determine when to turn the battery off. The off/on

process is determined by the average voltage curve derived from trials 3-5.

For water flow, angle fittings are used with the 1/4 piping. Small holes are drilled into

the small containers for ease of access. The pumps (connected to the tubing) are placed within

each circular container. Wires also connect the pumps to the main battery.

When the Arduino has detected completion of the desalination process, it cuts power to

the cell while retaining power to the pumps and switching power a series of UV lights located in

the circular product container, which serve to sanitize. The Arduino controls the UV lights and

pumps for a two-minute cycle, allowing the product compartment to fully cycle all of the potable

water, ensuring disablement and death of all biological organisms and pathogens (product

compartment flow rate = 1.5 min p500mL).

These components are placed within a plastic casing of 10 x 10 x 10. To create a

robust functionality allowing for easy user convenience of refilling the system with salt water, a

funnel is fixed into an external hole in the plastic casing. An LED indicator is also present on the

top of the plastic casing. When the Arduino continues to supply power to the battery, the LED

remains on. Once the Arduino cuts off the supply of energy, the LED turns off, signaling to the

user that the water is completely purified.

On the surface of the plastic casing, a solar panel is fixed onto one of the external sides.

Wiring connects these solar panels to the series of batteries on the inside.

As the desalination process achieves completion, an external switch allows the two

byproduct streams meet up in a separate internal chamber. This allows the two byproducts to

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neutralize each other. This also leads to an external spigot that allows safe disposal of dangerous

byproducts.

Finally, within the product compartment (both cell product chamber and the external

circular product container) a piece of tubing is positioned functioning to connect to an external

spigot for convenient output of water. ! !

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Market!Plan!Freshwater availability is the greatest global risk based on impact to society, as a measure

of devastation (World Economic Forum, 2015). Only 2.5% of the earths water resources are

freshwater. 70% of that 2.5% is frozen in the ice caps of Antarctica and Greenland; only 0.7% of

the worlds total water resources is available for use. Currently, this means that 900 million

people rely on unimproved drinking water. By 2025, domestic freshwater use is expected to rise

by 150%. Within the next 50 years, as developing countries increase their water needs, experts

predict that a volume of freshwater analogous to 3-5 planets will be needed.

However, even these statistics do not account for another potentially troubling factor:

climate change. Climate change intensifies the water cycle, causing the processes of evaporation

and transpiration to become faster decreasing the worlds freshwater availability. Global

warming also intensifies the process of precipitation, causing the atmosphere to hold a greater

amount of water, which in turn leads to heavier rainfall when the air cools. Although increased

Expected&Water&Availability&in&2025&

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rainfall may lead to temporarily increased freshwater resources in some areas, heavier rainfall

also means that water moves more rapidly from the atmosphere to the oceans, reducing our

ability to store and use it, thus decreasing freshwater availability. An increase of 2C would also

cause a 5-15% depletion of groundwater resources. Additionally, global warming would

cause the glaciers to melt, converting over 70% of the worlds freshwater resources to salt

water.

While the situation may be dire, there is great opportunity in utilizing a major untapped

reservoir: the ocean. Although desalination techniques exist, there are a very limited number in a

portable form; most processes are only capable of function on an industrial level. A portable

purification and desalination device would revolutionize the water supply industry. However,

converting salt water to clean drinking water on a portable scale presents a dilemma: the leading

desalination processes, reverse osmosis and nanofiltration, require huge pressures ranging from

50 to 1,000 psig, and is therefore energy and capital intensive. In contrast, electrodialysis is a low

pressure desalination process requiring lower power (electricity), making it the most suitable

choice for a portable device.

The IPDEDS meets the unmet needs of segments of population having access to sea

or brackish water, limited power supply and low investment time and capital. Populations

such as people in poor coastal regions, defense personnel in tactical and advance units, and

populations affected by natural disasters are primary targets for this device.

Out of the 900 million people living in water stressed areas, 37% live in Africa, with a

majority living along the northern and southern coasts. With the potential to desalinate 4.8 L per

day, many of these coastal countries will experience massively decreased water stress. In

addition, with 80% of illnesses in developing countries related to poor water conditions, the

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device can also lead to an increase in life expectancy by contributing to decrease in disease and

deaths.

Increased freshwater availability also tackles another hard fought problem: economic

development. Every dollar spent on water and desalination generates another $8 as a result of

saved time, increased productivity, and reduced health care costs. By increasing freshwater

resources, African countries can potentially achieve 5-25% gains in GDP.

The portable salt water desalination system can also be used for military applications. For

example, it could be used by troops in long distance combat missions, as an emergency kit for

naval departures, or as a resource for long-term stays in coastal regions. The device provides a

reliable source of clean water, regardless of initial water condition. With increased US defense

presence in the Middle East and other water stressed areas, this device could be of great utility to

the tactical and advanced forces in the field. Historically, military personnel have suffered from a

lack of clean water. For example, 2/3 of the soldiers who fought in the American Civil War died

from poor water and sanitation conditions. With this device in place, units will be kept fit and

healthy, avoiding possible illness or death from water-related causes.

Troops are currently supplied with the life straw, a device that separates water from

impurities through pressure created by the vacuum of your mouth. However, this device does not

filter out salt; it only separates micro-organic particles. Although this device is lightweight, the

life straw cannot create drinkable water for troops stationed near saltwater, effectively curtailing

its practical usage. In contrast, the electrodialysis device is practical for brine and brackish water.

Another possible use for the desalination system is in survival applications such as

hurricanes, earthquakes, and shipwrecks. As an interesting observation, two large ships are lost

at sea every week worldwide. When resources are low, the portable desalination system could

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supply the crew of these ships with water from the ocean around them, preventing dehydration.

In the worst case scenario of a shipwreck, survivors are often isolated with few supplies. In a life

raft supplied with the device, shipwreck survivors would have a supply of life-supporting water,

living up to 8 to 10 days longer, providing a greater period of time for rescuers to find them.

Most life rafts are equipped with solar stills. Solar stills desalinate water by using the heat

of the sun to evaporate water, cooling the device, and then collecting the water. However, they

are unpredictable and inefficient due to their reliance on external factors. Solar stills rely on

favorable weather conditions to operate at the maximum efficiency of 0.8 liters per kWh it

needs a clear and sunny day, in addition to considerably warm temperatures, to operate

efficiently. If the weather conditions are not favorable, the solar still could be easily destroyed or

simply not effective. In the U.S. alone there are up to 60-70 major and minor storms on a yearly

basis. Thus, relying on a solar still during a shipwreck a gamble. In contrast, the electrodialysis

device relies solely on electricity, making it more reliable during storms and other weather

conditions. In addition, the device is more efficient, producing 2 liters per day on 2 Ah, scaling

up to 4.8 liters per day on 5 Ah.

Overall, the portability of a salt desalination system can make a huge impact on the

market. With 900 million people lacking adequate water supplies, there is a market for 225

million devices, assuming a family of 4. With an active frontline personnel population of 1.4

million and an average platoon size of 25 men, there is another market for 56,000 devices in the

military alone. As a survival device, there is a market of over 12.077 million devices as there are

430 naval ships in active service and the reserve fleet, 86,733 commercial ships, and 11.99

million recreational boats

!

! 27!

Military, survival, and even third world needs are just a few of the significant

applications the portable salt water purifier can satisfy. As a device more efficient and effective

than alternate forms of water desalination and purification, there is a promising market potential

for this innovative product. In summary, there is a very sizable market opportunity for IPDEDS.

!

! 28!

Research!and!Explanation!of!Existing!Technology!

In recent decades, one of the most prevalent issues worldwide has been the need for an

easily-accessible, potable water supply. It has been projected that there will be a 53% increase in

the global needs of water, from 4500 billion m3 to 6900 billion m3, by the year 2030.

Consequently, as scientists have turned to a previously ignored source of water, the oceans, to

prevent further shortages. In the past 50 years, scientists have developed two distinct methods of

desalinating ocean water, thermal distillation and membrane technologies. While these

technologies have demonstrated potential in the industrial setting, each newly developed

technique possesses the same major flaws when applied to fundamental use: high energy usage

and extremely high capital and/or operating costs.

The Dow High team worked to combat these issues by constructing an energy-

independent, cost-effective electrodialysis cell that utilizes membrane technologies on a small

scale to produce 500-600 milliliters of drinking water in a 2.5 hour time period. Current

electrodialysis technologies are primarily used in the industrial setting to desalinate brackish

water, rather than seawater, because of the large energy usage of the ion-exchange membranes

necessary at high salinity levels. The Dow High electrodialysis cell utilized hybrid dimethyl

membranes which dramatically reduce the energy consumption of the cell, while still recovering

large volumes of water. While existing electrodialysis technologies are not primarily used for

desalination, a major problem in these technologies is the need for the resulting water to be

treated for pathogens before it is safe to drink. Another major problem in current electrodialysis

technologies is the need for the resulting water to be treated for pathogens before it is safe to

drink. The Dow High team addressed this problem by implementing 250-260 nanometers

!

! 29!

wavelength UV lights into the design. This UV light disinfects the water by breaking molecular

bonds within bacterial and viral DNA, thereby killing and disabling the microorganisms. The

team also worked to create a technology that was entirely energy-independent and portable by

utilizing photovoltaic cells to supply both the current for ion exchange and minimal power

required for the pumps. This innovation allows for the cell to function in a broad range of

applications, such as emergency survival and military equipment, unlike the static industrial

water conversion plants. Dow Highs electrodialysis cell exhibits promising future potential as

well. The team has the ability to further optimize the efficacy of the electrodialysis cell by

reducing the distance between the cation and anion membranes, in order to decrease the

electrical resistance. Increasing the flux of the membranes so larger volumes of ions are able to

pass through would also improve the performance of the cell, allowing more potable water to be

recovered in an even shorter time frame.

In comparison to thermal technologies, the earliest attempts at the desalination of water,

electrodialysis demonstrates far greater efficiency at both lower energy and financial costs.

Thermal desalination operates by heating saline water to a boil and collecting the condensed

vapor in order to produce potable water. This process, called distillation, has been divided into

three groups of technologies based on the heat source and pressure under which the system

functions. These groups include Multi-Stage Flash Distillation (MSF), Multi-Effect Distillation

(MED), and Vapor Compression Distillation. MSF Distillation alone produces 42% of the

worldwide desalination capacity. However, this process works at an incredibly low efficiency

and involves exceptionally high costs. Only a small percentage of feed waterwater that is led

into the cell to be desalinatedis actually converted into water vapor and condensed, leading

this process to be inefficient and time consuming. In comparison, the electrodialysis cell operates

!

! 30!

at nearly 100% efficiency, dramatically reducing costs and the duration of the desalination

process. The design of the MSF unit itself has a high opportunity cost as well, in that the MSF

plants are subject to corrosion, erosion, and impingement attacks unless stainless steel is used for

every piece of equipment, which leads to skyrocketing expenses. Another disadvantage of this

distillation process is the energy need to desalinate 500 milliliters of seawater. Due to the high

enthalpy of vaporization of water, MSF distillation requires 1131 kilojoules to boil 500 milliliters

of water, whereas electrodialysis requires only 57.8 kilojoules. This is expressed as an almost 20

fold decrease in energy usage for the Dow High electrodialysis cell. The less widely used MED

process also requires large amounts of energy for very little water production due to the low

pressures of the system. Finally, Vapor Compression Distillation is externally dependent and

requires a mechanical compressor to generate heat for the evaporation process. The technology is

also small in capacity, resulting in reduced water output for similar energy costs .

Another membrane technology comparable to electrodialysis, reverse osmosis, utilizes

pressure to force seawater through a semi-permeable membrane, leaving the salt behind. One

disadvantage of this mechanism is the need for pretreatments of the water such as coagulation,

sand filtration, or ultrafiltration. This pre-conditioning of water is needed to protect the

membranes, and the extent of these pre-treatment requirements depends on a variety of factors,

such as seawater composition and temperature, seawater intake, membrane materials, and

recovery ratio. This leads to high upfront costs that are not necessary for the electrodialysis cell

since water does not pass through the membranes during the electrodialysis desalination process.

Reverse osmosis also requires high pressure pumps that range from 800-1,000 psi, compared to

the pumps needed for electrodialysis which are both cheaper and more efficient because they

operate at a much lower pressure of 70 psi, with a comparable flow rate of 100 milliliters in 20

!

! 31!

seconds. Furthermore, reverse osmosis is only approximately 50% efficient for seawater because

a large portion of feed water must be discharged as concentrate, in order to prevent the super-

saturation of salts within the unit. Ultimately, electrodialysis proves to have a higher efficacy

than reverse osmosis because it is selectively permeable to ions, thereby not allowing the

movement of large water molecules through the membranes, resulting in a faster rate of

desalination.

!! !

!

! 32!

Financial!Plan!Electrodialysis Cell Budget! ! !

!

!!!

BUDGETED AMOUNT $1,000.00 $1,000.00! ! TOTAL COSTS $907.91! ! $907.91 91%! ! DIFFERENCE 9%! ! $92.09

Expenditure Location Notes Cost

Carbon Paper Staples Filter for initial water ! $19.99 300V Rubber Cord 1/4" x4 Home Depot $1.72 Clear Acrylic Sheet (.22x24x28) Home Depot $59.97 Noninsulated Alligator Clips Home Depot! Testing ! $4.38 10' Vinyl Tube 1/4" Home Depot $5.16 LOCTITE M&C Epoxy Home Depot! ! $4.99 !LOCTITE Plastic Epoxy Home Depot! ! $5.47 !Silicone Sealant Home Depot! Used for initial Wood Cell ! $5.68 !Terminal and Crimping Tool Kit Home Depot! ! $5.95 !Clear Acrylic Sheet (0.93x11x14) Home Depot! Used for initial Wood Cell ! $33.46 !25' Polyethylene Tubing 1/4" McMaster! Not used in final experimental cell ! $18.50 !24"x24" Polypropylene Sheet 1/4" McMaster ! Polyethylene is resistant to both base ! $33.32 !12"x24" Polypropylene Sheet 1" McMaster! and acid ! $63.89 !2' 36" Width Neoprene Rubber 1/8" McMaster! ! $72.20 !AMI-7001S Anion Membrane Sheet 48"x20" Membranes Int. ! ! $125.00 !CMI-7000S Cation Membrane Sheet 48" x 20" Membranes Int. ! ! $125.00 !12" Stainless Steel Tubing 1/8" McMaster! Not used in final experimental cell ! $8.04 !UV lights (380 nm) x10 SuperBright LEDs! ! $6.70 !Male Connector 1/8" tube x 1/8" MNPT x2 Midland Valve! ! $15.00 !Ferrule Set 1/4" Tube x4 Midland Valve! ! $3.72 !Polyethylene 1/4" x15' Lowe's! ! $2.85 !6' Solid Bare Copper Tubing 1/8" Lowe's! ! $1.78 !No 10 Screws x 12 Lowe's! ! $1.96 !No 10 Flat Washers 24 CT Lowe's! ! $0.98 !1/4" P2C x 1/8" MIP x4 Lowe's! ! $12.76 !

$0.00$200.00$400.00$600.00$800.00

$1,000.00$1,200.00

EXPENSES

Initial Costs Avaliable

Budget

Expenditures Avaliable

!

! 33!

Arduino Uno GearBest! ! $5.52 !Portable DC 12V 15000mAh Li-ion Battery x2 Ebay! ! $66.38 !DC-DC Adjustable Voltage Regulator Module Vetco Electronics! ! $6.95 !Global Pipe Fitting 90 Degree Tee Global Industrial! ! $4.70 !1/4" OD Tube x 1/4" OD Tube LIQUIfit Union Elbow x10 US Plastic Corp. ! ! $19.20 !PowerFilm OEM Flexible Solar Paneling x4 SolarMade! ! $112.68 !X2Power Rechargeable NiMH D Battery 2 Pack Batteries and Bulbs! ! $30.99 !Benziomatic Silver Solder Kit w/Flux Home Depot! ! $5.97 !Lead Free Silver Solder Home Depot! ! $4.61 !Hose Clamp 7/32" to 5/8" SS x8 Home Depot! ! $11.92 !304 Stainless Steel Sheets 5"x5" x2 Midland Steel! ! $0.52 !

Cost Analysis for Experimental Electrodialysis Cell Note: Costs in Bulk estimated from producers price! ! Item Comments! Cost ! Cost in Bulk!7"x7" Anion Membrane $6.38 ! $2.72 !7"x7" Cation Membrane $6.38 ! $2.72 !7"x7" w/ 5.5"x5.5" cutout rubber gaskets x4 $2.09 ! $0.78 !1/4" 7"x7" w/ 5.5"x5.5" cutout Polyproplene Sheet Inner Compartment! $1.08 ! $0.27 !1" 7"x7" w/ 5.5"x5.5"x.0.75" milled out Polyproplene Sheet x2 Outer Compartment! $10.87 ! $1.08 !

304 Stainless Steel 5"x5" Sheet x2 Estimated Price! $0.52 ! $0.52 !6" Solid Bare Copper Tubing 1/8" $0.15 ! $0.15 !1/4 of Ferrule Set 1/4 Tube $0.23 ! $0.11 !No 10 Screws x 12 $1.96 ! $0.55 !No 10 Flat Washers x12 $0.49 ! $0.15 !Male Connector 1/8" tube x 1/8" MNPT x2! ! $15.00 ! $3.56 !1/4" P2C x 1/8" MIP x4! ! $12.76 ! $4.09 !Polyethylene Tubing 1/4" 2' $0.38 ! $0.38 !Total: $58.29 ! $17.08 !

Cost Analysis for Inclusive Final Model Note: Costs in Bulk estimated from producers price! ! Item! Notes! Cost! Cost in Bulk!Electrodialysis Cell (from above) After Process Economics! $58.29 ! $17.08 !Plastic Shell (3D Printed) 1'x1'x1' Estimated Price! $0.16 ! $0.16 !X2 Power Rechargeable NiMH D Battery (1) $15.49 ! $15.49 !PowerFilm OEM Flexible Solar Paneling x1! $28.17 ! $11.68 !1/4" OD Tube x 1/4" OD Tube LIQUIfit Union Elbow x8! $15.36 ! $10.24 !DC-DC Adjustable Voltage Regulator Module ! $6.95 ! $0.57 !Global Pipe Fitting 90 Degree Tee (cross fitting)! $4.70 ! $2.74 !Arduino Uno! ! $5.52 ! $5.52 !UV lights (380 nm) x3! ! $2.01 ! $2.01 !LED (1) Estimated Price! $0.15 ! $0.15 !Wiring Estimated Price! $0.20 ! $0.20 !Total: $137.00 ! $65.84 !

!!

!

! 34!

Funding!!! The team used the $1,000 grant to purchase the materials necessary to produce, test,

and improve on two iterations of their electrodialysis cell, as well as produce an early prototype

of the IPDEDS, a potential product Due to many of the materials being industrial-grade and not

commonly available to individual consumers, 91% of the grant was used.

The first iteration of the cell expended 14.66% of the grant. The largest cost was clear

acrylic sheets, items that would not be used in further development. Plywood, a potentially large

cost, was sourced for free from the schools woodshop. A few of the items bought in this stage

were tools for future testing the alligator clips, sealant, and epoxies were used for the plastic

cell and the final model. On the other hand, many of the items bought were not used in either

further testing or construction. For example, the rubber cord, vinyl tubing, and acrylic sheets

were deserted.

Although the total initial cost of the cell was only $58.29, 49.1% of the grant was used in

the second iteration of the cell. Many products were industrial materials not readily available to

the average consumer, causing inflated costs. Specifically, many of the fittings and plastics are

far cheaper in huge quantities. Some of these industrial materials also came in sizes or quantities

not ideal for development, and extra funds were spent on acquiring excessive material. For

example, the ionic exchange membranes were 19.5x larger than necessary. During the

development of this second iteration, some of the materials were bought and then exchanged for

other materials. The polyethylene tubing bought from McMaster was too thick to fit into fittings,

and was eventually swapped for polyethylene tubing from Lowes.

Costs derived from the development of the final model amounted to 26.4% of the grant.

Costs were inflated for similar reasons: fittings were far more expensive in small quantities and

!

! 35!

excess solar paneling was bought. Upon concluding development, the final models initial costs

amounted to $137.00. However, when buying in bulk, the cost of the final model decreases to

$65.84. Upon the development of streamlined processes involved in procurement and creation,

the cost of production decreases to $50.00.

In order to the secure the funding required to achieve these economies of scale, the Dow

High Team will apply to a variety of grants. The funding would allow for the further

development of the IPDEDS. The team would seek to receive a grant from the US Department of

the Interior Bureau of Reclamations Desalination and Water Purification Research Program.

This program allows research and studies to receive up to a maximum of $5 million per year.

The team believes that the IPDEDS has a key advantage in applying for this grant: in contrast to

other desalination techniques the IPDEDS is mobile and extremely valuable on a local scale.

The team also aims to gain funding from the California Department of Water Resources.

This department offers $8.7-$21.5 million dollars for the development of water desalination. The

team believes that the IPDEDS is positioned to win funding due to Californias current

conditions. It has been forecasted that in 12-18 months, 22 million people will be without

freshwater. The IPDEDS could provide a source of freshwater to an area severely impacted by

drought.

In addition, the team plans on seeking funding from the United States Senate Drinking

Water State Revolving Fund Loan Program. Each state has a fund of $8,787,000 to $82,674,000

to use in funding for the development of drinking water systems. The IPDEDS is a revolutionary

product in drinking water production because of its ability to portably desalinate salt water. This

ability dramatically increases the availability of salt water in coastal regions.

!

! 36!

The team also aims to secure their intellectual property through a variety of patents. The

IPDEDS will be secured through an integrated systems patent, providing 12-14 years to develop

better versions of the device. The design and construction methods of the cell will also be

patented, providing additional security.

!

The graph above demonstrates the process economics of the three distinct levels of

production. In the current prototype stage, material and production costs remain high. However,

as production begins to increase into the hundreds, cost of materials and production is driven

down by the quantity produced. In the final commercial stage, the costs are further lowered with

a massive increase in quantity produced. A profit margin of 20% is applied to the costs in all

levels of production. The process economics of the IPDEDS clearly demonstrates the ability to

lower the price of the device with an increase in quantity produced. The projected commercial

price is a testament to the cost- effective nature of the IPDEDS.!

!

! 37!

! The graph above shows the increased cost effectiveness of the electrodialysis cell with

modular scaling. The addition of one product chamber, which only adds to the overall

IPDEDS size, effectively doubles the purified water output only at a linear marginal cost of

$1.56 per unit. While one product chamber yields a cost of 2.5 cents per liter of water, an

increase of 4 modules decreases the cost of each liter to an astonishing half cent.

!

! 38!

Project!Management!&!Timeline!

!!!!!!!!!!!!!!

!

! 39!

Graphical!Representation!

!

!

! 40!

1

1

2

2

3

3

4

4

A A

B B

C C

D D

SHEET 1 OF 1

DRAWN

CHECKED

QA

MFG

APPROVED

sarkars 3/8/2016

DWG NO

Expanded Assembly

TITLE

SIZE

CSCALE

REV

!

! 41!! !

1

1

2

2

3

3

4

4

A A

B B

C C

D D

SHEET 1 OF 1

DRAWN

CHECKED

QA

MFG

APPROVED

sarkars 2/29/2016

DWG NO

Outer Membrane

TITLE

SIZE

CSCALE

REV

7.00

7.00

5.50

5.50

1.00

.375

.50

3.50

3.50

.125

2.00 2.00

.375

2.00 2.00

Outer Membrane

Electrode Rod

1

1

2

2

3

3

4

4

A A

B B

C C

D D

SHEET 1 OF 1

DRAWN

CHECKED

QA

MFG

APPROVED

sarkars 2/29/2016

DWG NO

Inner Membrane

TITLE

SIZE

CSCALE

REV

7.00

7.00

3.50

5.50

5.50

2.002.00 .196

.375

.375

Clearance Hole

Water Tubes

Inner Membrane

2.00 2.00

.125

!

! 42!

1

1

2

2

3

3

4

4

A A

B B

C C

D D

SHEET 1 OF 1

DRAWN

CHECKED

QA

MFG

APPROVED

Abhijit 3/31/2016

DWG NO

Assembled Assembly Assembly

TITLE

SIZE

CSCALE

REV

!

! 43!

Appendix!A!!

!Cell&Assembly&

Cell&Assembly&

Electrodialysis&Cell&Experimentation&Setup& Pure&Water&Recovery&PostKExperimentation&

!

! 44!

!Rubber&Gasket&

Outer&Chamber&

Cell&Vertical&View& Cell&Horizontal&View&

!

! 45!

!Inner&Chamber&Side&View&

Inner&Chamber&Front&View&Copper&Electrode&w/o&Electrode&Wire&

Outer&Chamber&with&Copper&electrode&and&Electrode&Wire&Inner&View&

!

! 46!

!Inner&Chamber&with&Copper&Piping&and&Fittings&

!!

Outer&Chamber&with&Electrode&and&Electrode&WIre&Outer&View&

Blowtorch&Soldering&Copper&Wire&to&Electrode&Cell&Side&View&

!

! 47!

!Cell&Side&View&

!

!Blowtorch&Soldering&Copper&Wire&to&Stainless&Steel&Electrode&

!

Cell&Side&View&

Stainless&Steel&w/&Copper&Wire&in&Outer&Chambers&

!

! 48!

!Early&Drawing&of&the&IPDEDS&

! !

!

! 49!

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!!