U.S. Department of the Interior

Bureau of Reclamation September 2016

Paradox Valley Unit Brine 

Crystallization Technology 

Assessment

Western Colorado Area Office

Paradox Valley Unit, Colorado

Upper Colorado Region

Mission Statements

The U.S. Department of the Interior protects America’s natural 

resources and heritage, honors our cultures and tribal communities, 

and supplies the energy to power our future.

The mission of the Bureau of Reclamation is to manage, develop, 

and protect water and related resources in an environmentally and 

economically sound manner in the interest of the American public.
Paradox Valley Unit Brine Crystallization 

Technology Assessment

Paradox Valley Unit, Colorado

Western Colorado Area Office

Prepared by:

Technical Service Center

Water Treatment Group

Katie Guerra, Ph.D., P.E.

Andrew Tiffenbach

Julie Korak, Ph.D.

Anthony Kennedy, Ph.D.

For:

Western Colorado Area Office

Upper Colorado Region
Acronyms

°C Celsius degrees

$ dollar

% percent

$M million of dollars

$M/yr million of dollars per year

/ton solids per ton of solids

AC alternating current

BBT Brine Bulb Technology

brine saline water 

CDS concentrated draw solution

CO2/yr carbon dioxide per year

DC direct current

DDS diluted draw solution

d/w days per week

EDI Electrodeionization

EDR Electrodialysis Reversal

EIS Environmental Impact Statement

EVRASTM Evaporative Reduction and Solidification

ft foot/feet

ft2 square foot

FTE® Freeze Thaw/Evaporation

Gal gallon

gpd gallons per day

gpm gallons per minute

HDH humidification-dehumidification

hr/d hours per day

kg kilogram

kWh kilowatt hour

lbs pounds

MBC Membrane Brine Concentrator

MD Membrane Distillation
MED Multi-Effect Distillation

MGD million gallons per day

mg/L milligrams pre litre

MOhm-cm mega ohm-centimeter

MSFD Multi-Stage Flash Distillation

MVC Mechanical Vapor Compression

MVR mechanical vapor recompression

MW megawatts

MWh/yr megawatts hours per year

NREL National Renewable Energy Laboratory

O&M operations & maintenance

PV present value

PVU Paradox Valley Unit

Reclamation Bureau of Reclamation

RFI request for information

RO reverse osmosis

TCLP Toxicity Characteristic Leaching Procedure

TDS total dissolved solids

TVC Thermal Vapor Compression

WAIV Wind-Aided Intensified Evaporation

WCAO Western Colorado Area Office (Reclamation)

ZLD zero liquid discharge

vi

Contents

Project Scope and Objectives........................................................................................................... 8

Brine Water Quality .................................................................................................................. 10

Preliminary Technology Screening................................................................................................ 11

Preliminary Screening Approach and Summary ....................................................................... 11

Technology Descriptions........................................................................................................... 15

Brine Bulb Technology.......................................................................................................... 16

Crystallization........................................................................................................................ 18

Evaporative Reduction and Solidification System (EVRASTM)............................................ 20

Forward Osmosis with Crystallization................................................................................... 22

SAL-PROCTM ........................................................................................................................ 24

Dewvaporation....................................................................................................................... 26

Electrodeionization (EDI)...................................................................................................... 28

Electrodialysis Reversal (EDR)............................................................................................. 30

Freeze Thaw/Evaporation ...................................................................................................... 32

Membrane Distillation (MD)................................................................................................. 34

Multi-Effect Distillation (MED)............................................................................................ 36

Multi-Effect Distillation Mechanical Vapor Compression (MED-MVC)............................. 39

Multi-Effect Distillation Thermal Vapor Compression (MED-TVC) ................................... 41

Multi-Stage Flash Distillation (MSFD) ................................................................................. 44

Pellet Softening...................................................................................................................... 46

Wind Aided Intensified Evaporation (WAIV)....................................................................... 49

Technology Assessment................................................................................................................. 51

Technical Comparison............................................................................................................... 53

Economic Comparison .............................................................................................................. 54

Approach and Assumptions................................................................................................... 54

Results.................................................................................................................................... 54

Preliminary Renewable Energy Assessment.................................................................................. 56

Photovoltaic Solar ..................................................................................................................... 56

Solar Thermal ............................................................................................................................ 58

Geothermal ................................................................................................................................ 59

Technology Testing ....................................................................................................................... 62

On-Site Demonstration Testing Recommendations.................................................................. 63

References...................................................................................................................................... 64

Appendix A - Vendor Information Request Sheet................................................................ A1

Tables

Table 1— PVU Brine Water Quality..........................................................................................................10

Table 2— Preliminary Screening of ZLD Treatment Technologies...........................................................12

Table 3— Preliminary Screening of Non-ZLD Treatment Technologies...................................................13

Table 4 — PV comparison of Brine Treatment Processes for the PVU. ....................................................55
vii

Figures

Figure 1— PVU location ..............................................................................................................................8

Figure 2— Schematic of the BBT process..................................................................................................16

Figure 3— Schematic of a crystallization process......................................................................................18

Figure 4— Schematic of EVRASTM process. .............................................................................................20

Figure 5— Schematic of ClearFlo MBCTM process ...................................................................................22

Figure 6— Schematic of SAL-PROCTM process........................................................................................24

Figure 7— Schematic of AltelaRain® process...........................................................................................26

Figure 8— Schematic of EDI process.........................................................................................................28

Figure 9—Schematic of EDR process. .......................................................................................................30

Figure 10—Photo of FTE® field demonstration ........................................................................................32

Figure 11—Schematic of MD process........................................................................................................34

Figure 12— Schematic of MED process. ...................................................................................................36

Figure 13— Schematic of MED-MVC process..........................................................................................39

Figure 14— Schematic of MED-TVC process...........................................................................................41

Figure 15— Schematic of MSFD process..................................................................................................44

Figure 16— Schematic of a pellet softening process..................................................................................46

Figure 17— Schematic of the WAIV process ............................................................................................49

Figure 18— NREL map of photovoltaic solar resource potential ..............................................................57

Figure 19— NREL map of concentrating solar resource potential.............................................................58

Figure 20— Interpretive geothermal gradient map of southwest Colorado................................................60

Figure 21— NREL map of geothermal resource potential .........................................................................61
Paradox Valley Unit Brine Crystallization Technology Assessment

8

Project Scope and Objectives

The Paradox Valley Unit (PVU) is a Bureau of Reclamation (Reclamation) facility that collects 

hypersaline groundwater, or brine, from wells near the Dolores River in the Paradox Valley in 

Montrose County, Colorado, and injects the brine into deep geologic formations. The location of 

the PVU is shown in figure 1. Under the Colorado River Basin Salinity Control Act of 1974, the 

Western Colorado Area Office (WCAO) implements the PVU Project for salinity control. 

Currently the PVU is one of the most effective salinity control projects and provides about ten 

percent of the total salinity control in the Colorado River.

The PVU consists of a shallow collection well field, surface treatment facility, injection facility, 

and a 16,000-foot deep injection well.

Figure 1— PVU location (source: http://www.usbr.gov/uc/wcao/progact/paradox/).

The shallow collection wells intercept brine with approximately 260,000 mg/L of total dissolved 

solids (TDS) at 200 gallons per minute (gpm) as it travels through the ground toward the Dolores 

River. Water from each well is combined in the surface treatment facility and pumped to the 

injection facility. At the injection well, brine is pumped into the ground for long-term disposal. 

This prevents approximately 100,000 tons of salt per year from entering the Dolores River, a 

tributary of the Colorado River.
Paradox Valley Unit Brine Crystallization Technology Assessment

9

The collection wells are capable of collecting 400 gpm. However salinity control benefits may 

decrease at collection rates greater than 300 gpm. Therefore, for the purposes of this study the 

goal is to manage 300 gpm of brine; this collection rate would reduce the salt loading to the 

Dolores River by 170,000 tons per year.

As the existing injection well reaches the end of its useful life, there is a need for evaluating 

alternatives other than deep well injection for the management of the brine and salinity control in 

the Colorado River. The purpose of this technical memorandum is to support the WCAO efforts 

for the on-going Environmental Impact Statement (EIS) for future PVU alternatives to the 

current injection well.

This technical memorandum provides a summary of the treatment technologies that were

investigated as alternatives to deep well injection including brine minimization and zero liquid 

discharge (ZLD) technologies. The scope of this assessment was limited to technologies that 

have the capability of producing a solid for disposal or would be an integral part of a ZLD 

process.

The objectives of this technical memorandum are to:

• Identify technologies with the capability to reduce the brine to a solid waste product

• Investigate the potential to incorporate alternative energy sources to offset process 

energy requirements

• Summarize and evaluate commercially available technology alternatives relevant to 

the PVU

• Provide recommendations for future on-site testing

Implementation of a brine crystallization technology would likely produce a solid waste product 

that would require permanent disposal in a solid waste landfill. Prior to disposal solids would 

have to be screened for hazardous constituents using the Paint Filter Liquids Test (SW-846 Test 

Method 9095B) and Toxicity Characteristic Leaching Procedure (TCLP, SW-846 Test Method 

1311). Consideration of solid waste handling and characterization was outside the scope of this 

effort.
Paradox Valley Unit Brine Crystallization Technology Assessment

10

Brine Water Quality

Technology screening depended heavily on the water quality of the PVU brine, which is 

presented in table 1. Complete analytical water quality results from the SGS Accutest Mountain 

States lab in Wheat Ridge, Colorado, were provided by WCAO. The data in table 1 are from 

sample ID D26319-2 in 2011, which was chosen because it was a composite sample from several 

wells.

PVU brine water quality is unique, because it has a high TDS) concentration of approximately 

260,000 mg/L. By comparison, seawater typically has a TDS of 35,000 mg/L, and reverse 

osmosis (RO) concentrate from a seawater desalination facility may have a TDS concentration 

around 70,000 to 100,000 mg/L. Therefore, the technologies considered and evaluation criteria 

were tailored to the high source water TDS, which is an uncommon initial salinity level for many 

desalination or brine management processes. PVU brine also contains hydrogen sulfide (H2S) 

which is dangerous to human and wildlife health when inhaled, and is also corrosive to process 

equipment. Although the dissolved concentration in table 1 is only 6 mg/L, project staff report 

typical H2S concentrations near 80 mg/L.

Table 1— PVU Brine Water Quality for Constituents Measured above the Method Reporting Limit 

(lab sample ID D26319-2)

Constituent Units Value

Alkalinity mg/L as CaCO3 210

Ammonia mg N/L 0.5

Bicarbonate mg/L as CaCO3 210

Boron mg/L 8.2

Calcium mg/L 1,320

Carbon Dioxide mg/L 90

Chloride mg/L 151,000

Hardness mg/L as CaCO3 9,470

Hydrogen Sulfide mg/L 6.2

Magnesium mg/L 1,500

Manganese mg/L 0.3

pH Standard Units 6.7

Potassium mg/L 4,080

Sodium1 mg/L 94,800

Specific Conductance mS/cm 210

Strontium mg/L 25

Sulfate mg/L 5,980

Sulfide mg/L 50

Total Dissolved Solids mg/L 259,000

Turbidity NTU 40

1Sodium was not in the analytical reports but as determined by a mass/charge balance.
Paradox Valley Unit Brine Crystallization Technology Assessment

11

Preliminary Technology Screening

Preliminary Screening Approach and Summary

High level screening was conducted to identify potential technologies for further investigation at 

the PVU. Technologies were considered to have potential if they met the following screening 

criteria:

• Can the technology process brine concentrations of 260,000 mg/L?

• Can the technology produce a solid product (i.e., ZLD) or pretreat water in 

anticipation of a ZLD process?

• Has the technology been previously demonstrated?

• Is the technology commercially available?

Preliminary screening included technologies that either reduce brine volume or produce a solid 

product. Some of the technologies that were considered are stand-alone systems capable of 

reducing the brine to a solid product. However, some technologies that cannot produce a solid 

product can be used as part of a treatment train to further concentrate the brine prior to a ZLD 

process. Brine concentration prior to a ZLD process can improve energy efficiency of 

downstream unit operations. For example, crystallizers often follow brine concentrators, which 

reduce the volume to be processed by the crystallizer.

Due to the high TDS, pressure driven membrane technologies, such as RO, were not considered 

because of the high pressure requirements that would result in high energy requirements, 

operational challenges, and potential safety concerns. Recovery of fresh water from the brine 

was also not a priority of the WCAO. Other efforts by Reclamation are evaluating conventional 

evaporation ponds and were therefore not considered herein. Natural treatment systems (e.g., 

wetlands, halophyte farming) were not considered due to the large footprint that would be 

required to meet the PVU brine flow rates.

Through alternative development efforts for the on-going PVU EIS, it is anticipated that the solid 

waste produced from any alternative would be permanently stored in a solid waste landfill. 

Based on conversations with a landfill operator in the Paradox Valley, a material must pass the 

paint dry test in order to be considered a solid waste. Prior to disposal solids would have to be 

screened for hazardous constituents using the Paint Filter Liquids Test (SW-846 Test Method 

9095B) and TCLP (SW-846 Test Method 1311). Where possible, information was obtained for 

anticipated solid waste characteristics.

Table 2 and table 3 provide a summary of potential technologies, descriptions, and commercial 

vendors for ZLD and non-ZLD processes, respectively. The final column in table 2 and table 3 

indicates whether the technology met the initial screening criteria. In general, a generous 

approach was taken in determining whether a technology met the screening criteria. Only 

technologies that were poorly suited to the application were eliminated from further evaluation. 

In the section titled Technology Descriptions, more detailed explanations are provided for all 

technologies included in preliminary screening. Information presented below was gathered from 

publicly available sources.
Paradox Valley Unit Brine Crystallization Technology Assessment

12

Table 2— Preliminary Screening of ZLD Treatment Technologies

Technology/

Process

Description Product(s) Vendor(s) Meets Initial

Screening Criteria

Brine Bulb

Technology

(BBT)

Electro-coagulation 

precipitates solids 

and heats brine for 

vacuum distillation

Distilled water, wet 

solids

Eric Dole with Hazen 

and Sawyer

No, technology is still 

in the early phases of 

development

Crystallization Heat vaporizes water 

in the concentrated 

brine, precipitating 

salt crystals

Distilled water, wet 

solids

GE Water, Aquatech, 

Saltworks, 

Degremont, Veolia, 

GEA, WaterFX, 

Swenson, 

Ecoplanning, Suez

Yes

Evaporative

Reduction and 

Solidification

(EVRASTM)

Heat evaporates 

water from preheated 

brine in a high 

surface area cooling 

tower coupled with a 

crystallizer

Wet solids Layne Yes

Forward Osmosis

(ClearFlo

CompleteTM)

A thermolytic draw 

solution concentrates 

brine using forward 

osmosis coupled with 

a crystallizer

Wet solids Oasys Water Yes

SAL-PROCTM System couples a 

series of chemical 

reaction steps, 

evaporation, and 

cooling

Specific wet solids 

(e.g., gypsum)

Geo-Processors, Inc. No, technology 

appears to be cost 

effective only when 

salable by-products 

are produced
Paradox Valley Unit Brine Crystallization Technology Assessment

13

Table 3— Preliminary Screening of Non-ZLD Treatment Technologies

Technology Description Product(s) Vendor(s) Meets Initial

Screening Criteria

Dewvaporation

(AltelaRain®)

Thermal process 

operating below the 

boiling point of water 

(humidificationdehumidification) to 

evaporate water

Distilled water, 

concentrated brine

Altela Yes

Electrodeionization

(EDI)

Electrochemical 

process using 

electrodes separated 

by anion and cation 

ion exchange resins 

to remove salts

Ultrapure water, 

concentrated brine

GE Water, Veolia, 

Dow Water, Cal 

Water, SnowPure 

Water Technologies, 

Evoqua

No, not intended for 

high salinity brines

Electrodialysis

Reversal (EDR)

Electrochemical 

process using 

electrodes separated 

by anion and cation 

selective membranes 

to remove salts

Ultrapure water, 

concentrated brine

GE Water, Evoqua No, not intended for 

high salinity brines

Freeze

Thaw/Evaporation

(FTE®)

In cold weather 

climates, fresh

water is separated 

from brine

through freezing

Fresh water, 

concentrated brine

Polar Bear Water 

Treatment

No, because of 

requirement for 

consistent below 

freezing temperatures

Membrane

Distillation

(MD)

Hydrophobic 

membranes separate 

water from heated 

brine stream to form 

condensed water 

vapor

Fresh water, 

concentrated brine

Solar Spring, 

Aquaver, Memsys

No, technology is still 

developing and 

requires a large 

footprint

Multi-Effect

Distillation

(MED)

Steam heat and 

reduced pressure 

evaporate water in 

several stages 

followed by 

condensation

Distilled water, 

concentrated brine

Sidem, Wabag, 

AquaSwiss AG, IDE 

Technologies, Alfa 

Laval

Yes

Multi-Effect

Distillation

Mechanical Vapor

Compression

(MED-MVC)

Steam produced by 

water evaporation is 

compressed using a 

thermocompressor 

and recycled as heat 

source for brine 

distillation

Distilled water, 

concentrated brine

Sidem, Aqua Swiss, 

IDE Technologies, 

Alfa Laval, Wabag

Yes

Multi-Effect

Distillation –

Thermal Vapor

Compression

(MED-TVC)

Steam produced by 

water evaporation is 

compressed with 

mechanical 

compressor and 

recycled as heat 

source for brine 

distillation

Distilled water, 

concentrated brine

Sidem, Wabag Yes

Multi-Stage

Flash Distillation

(MSFD)

Steam heat and 

reduced pressure 

flashes (boils) water 

in several stages

Distilled water, 

concentrated brine

Sidem, Wabag Yes
Paradox Valley Unit Brine Crystallization Technology Assessment

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Technology Description Product(s) Vendor(s) Meets Initial

Screening Criteria

Pellet Softening pH adjustment and 

use of ballast, such 

as sand, precipitates 

dissolved solids to 

form settleable and 

disposable pellets.

Wet solids, 

disposable pellets, 

less concentrated 

brine

Veolia, Rwb No, technology only 

precipitates minerals 

such as calcium 

carbonate and does 

not reduce brine 

volume

Wind-Aided

Intensified

Evaporation

(WAIV)

High surface area 

materials enhance 

wind-driven 

evaporation

Wet solids, 

concentrated brine

Lesico CleanTech Yes
Paradox Valley Unit Brine Crystallization Technology Assessment

15

Technology Descriptions

This section provides more detail for each brine management technology that was identified in 

table 2 and table 3. Each technology section provides a brief description, process schematic, 

advantages and disadvantages, list of vendors, and known applications. At the end of each 

technology section, the potential for direct coupling of renewable energy (solar thermal or 

geothermal) to offset heat requirements is addressed. Renewable energy is discussed further in 

the section titled Preliminary Renewable Energy Assessment.

For the technologies deemed potentially feasible for the PVU, information request sheets 

(Appendix A), were sent to vendors to allow for a more comprehensive alternatives assessment 

(see section titled Technology Assessment).
Paradox Valley Unit Brine Crystallization Technology Assessment

16

Brine Bulb Technology

Brine Bulb Technology (BBT) is a relatively new combination of technologies developed by 

Eric Dole with the engineering consulting firm Hazen and Sawyer. The process uses 

electrocoagulation to:

• Form floc seeds for solids precipitation and settling

• Warm the brine through the breaking of surface tension bonds between water 

molecules

• Reduce brine specific heat capacity

• Reduce brine latent heat of vaporization

Therefore electrocoagulation reduces the energy requirements for distillation, which is enhanced 

in the process using a vacuum. Although promising, BBT is still in the bench scale development 

phase.

Figure 2— Schematic of the BBT process (from 

http://www.desaltech2015.com/assets/presenters/Dole_Eric.pdf) “eq” refers to an equalization 

chamber, not shown in the figure.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces a slurry that can be dewatered

Low energy

Very early development stages

Vendors

None identified

Installations

None identified

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

This technology is still in the early phases of development and has not been sold as a commercial 

product. Therefore, Hazen and Sawyer was not contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

18

Crystallization

Crystallizers are used to precipitate solids that can be dewatered from pre-concentrated brine 

streams. The brine is typically concentrated using brine concentrators, which are very similar in 

principle to crystallizers. In a crystallizer, concentrated brine is recirculated between a heat 

exchanger and a main vessel where water vapor exits the top and salt crystals precipitate in the 

concentrated brine. Concentrated brine slurry from the bottom of the main vessel is discharged 

to a dewatering process such as a centrifuge. Crystallizers are commonly used when other 

disposal methods, such as deep well injection or ocean discharge, are not feasible. The Aqua4TM 

by WaterFX is similar to conventional crystallization processes, except it uses concentrated solar 

thermal arrays to heat the concentrated brine.

Figure 3— Schematic of a crystallization process (from http://www.gewater.com/zero-liquiddischarge-zld.html#featuredproductssection).
Paradox Valley Unit Brine Crystallization Technology Assessment

19

Advantages Disadvantages

Produces a solid that can be dewatered

Centrate from dewatered solids can be 

recycled

Many vendors with varying designs

Requires a readily available supply of steam 

and/or vapor compressor

Scaling and corrosion from inorganics

Energy intensive

Vendors

GE Water

Aquatech

Degremont Technologies

Saltworks Technologies, Inc.

GEA

Veolia

WaterFX

Swenson

Ecoplanning

Installations

Shenhua Coal Liquefaction Project, Inner Mongolia, 590 gpm, 2009

Huntington Power Station, Huntington, Utah, 200 gpm, 1974

Indiantown Generating Plant, Indiantown, Florida, 580 gpm, 1995

Gila River Power Station, Gila Bend, Arizona, 2400 gpm, 2003

PEMEX Cadereyta Refinery, Monterrey, Mexico, 116 gpm, 1998

Lithium chloride production, Argentina

Pure Salt Baytown, salt crystallization system, Baytown, Texas

IC Potash Corp., potassium sulfate crystallization, New Mexico

Potential for Integration with Renewable Energy

This technology is energy intensive because of the steam and power requirements. Solar thermal 

or geothermal heat could be used to offset heat requirements.

Technology Disposition

Crystallizers have been used extensively at the full-scale for similar applications, and there are 

numerous technology vendors. Therefore vendors that manufacture crystallizers were contacted 

for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

20

Evaporative Reduction and Solidification System (EVRASTM)

The EVRASTM by Layne is an integrated heating and evaporative process similar to cooling 

towers. Brine is first preheated in a direct contact floating bed heat exchanger, which eliminates 

problems associated with fouling and scaling. The heated brine is then sprayed over a flexible 

plastic film that provides high surface area for contact with ambient air flow. Humid air is then 

carried out of the unit by a fan as with cooling towers. Concentrated brine is collected at the 

bottom of the unit and either recycled to be heated again or discharged to solids handling after 

crystallization.

Figure 4— Schematic of EVRASTM process (from 

http://ipec.utulsa.edu/Conf2011/Full%20Manuscripts%20&%20PP%20presentations/Stone_56.pdf).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces a solid that can be dewatered Requires a heat source

Modular design Limited installations

No freshwater handling or discharge Only one vendor

Minimizes fouling and scaling associated

with traditional heat exchangers

Vendors

Layne

Installations

Deicing glycol regeneration plant, Newell, West Virginia

Food processing plant, Nevada

Gas field brine concentrator, California

Barnett shale site

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

EVRASTM produces a solid product and has several installations. Therefore Layne was 

contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

22

Forward Osmosis with Crystallization

ClearFlo Membrane Brine Concentrator (MBC)TM by Oasys Water is a forward osmosis and 

crystallizer system for the recovery of water from concentrated brine. Forward osmosis uses a 

semipermeable membrane to concentrate a brine solution based on an osmotic dilution process. 

Forward osmosis acts as a pre-concentration step prior to crystallization to reduce the energy 

requirements of evaporation in the crystallizer. Osmotic dilution occurs when a semipermeable 

membrane separates two fluids of different osmotic pressure. Water will permeate from the 

solution with the lower osmotic pressure (feed solution) to the solution with higher osmotic 

solution (draw solution). In this application, the brine acts as the feed solution. The 

concentrated draw solution (CDS) consists of a thermolytic salt that can exert a higher osmotic 

pressure than the feed solution. The end product from the forward osmosis process is 

concentrated brine and a diluted draw solution (DDS). The DDS is fed to a recovery system that 

can recover the thermolytic salt using low grade heat that is recycled for further separation. The 

concentrated feed solution (brine) passes to a crystallizer for to produce a solid product.

Figure 5— Schematic of ClearFlo MBCTM process

(from http://oasyswater.com/solutions/clearflo-complete/).
Paradox Valley Unit Brine Crystallization Technology Assessment

23

Advantages Disadvantages

Combined forward osmosis and 

crystallization reduces crystallization energy 

requirements

No thermal scaling during concentration as

forward osmosis is conducted at ambient 

temperatures

More energy efficient than evaporative 

technologies

Additional unit operations required for 

thermolytic draw solute recovery and 

recycling

Only one vendor

Limited full-scale installations

Vendors

Oasys Water

Installations

Power Plant Wastewater: Changxing, China (630 m3/day) 

Produced Water: Permian Basin, Midland, Texas

Produced Water: Marcellus Shale (4-month study treating 60,000 gallons)

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

ClearFlo CompleteTM system produces a solid product by using less energy than conventional 

systems. Therefore Oasys Water was contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

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SAL-PROCTM

SAL-PROCTM is a proprietary process developed by Geo-Processors, Inc. Through a series of 

reactions including conventional mineral and chemical processing steps, evaporation, and 

cooling, solids minerals, such as calcium chloride, are recovered from concentrated brine 

streams.

Figure 6— Schematic of SAL-PROCTM process (from 

http://www.geoprocessors.com/salproc.html).
Paradox Valley Unit Brine Crystallization Technology Assessment

25

Advantages Disadvantages

Produces a solid that can be dewatered

Produces salable products

Requires a heat source

Requires evaporation ponds

Limited installations, mostly field trials and 

pilot studies

Only one vendor

Vendors

Geo-Processors, Inc.

Installations

It is unclear from initial research if any full-scale, permanent installations exist.

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

No full-scale installations were identified and salable products are not desired at the PVU. 

Therefore, Geo Processors, Inc. was not contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Dewvaporation

Dewvaporation, or AltelaRain® by Altela, Inc., belongs to a class of technologies called 

humidification-dehumidification (HDH), which refers to thermal processes that operate below 

the boiling point of water. HDH processes operate based on the fact that hot air can carry more 

water vapor than cold air. Hot air in contact with salt water evaporates water, which results in 

cooling and a loss of sensible heat. Distilled water is recovered by contacting the humid air with 

a condensing surface. The condensation process produces heat that can be conveyed through a 

heat exchange surface back to the brine for continued evaporation. Dewvaporation differs from 

traditional HDH processes in that both water extraction and water condensation occur in the 

same heat exchanger tower.

Figure 7— Schematic of AltelaRain® process (from http://altelainc.com/).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Many commercial installations for difficultto-treat water types

Technology model for waste management 

(rather than “treatment”)

Reasonably low capital and operating costs

Requires a heat source

May require large footprint relative to 

volume of brine managed

Does not directly produce a solid that can be 

dewatered

Only one vendor

Vendors

Altela, Inc.

Installations

Leachate treatment facility, Pennsylvania

Clarion Altela Environmental Services Treatment Facility, Pennsylvania

South Platte River Basin Reverse Osmosis Brine, Colorado

Navajo Nation Waste-to-asset conversion, Navajo Nation, northwestern New Mexico

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

AltelaRain® has been used at the full-scale for similar applications. Therefore Altela, Inc. was 

contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Electrodeionization (EDI)

EDI is an electrochemical treatment method that is designed to produce ultrapure water 

(conductivity 5-17 MOhm-cm). Electrodes (i.e., anode and cathode) are used to induce ion 

transport towards the appropriate electrode. Between the electrodes lies both anion and cation 

ion exchange resins. Dissolved ions exchange sites on the resin releasing either protons (H+) or 

hydroxide ions (OH-) in their place. The system produces an ultrapure product and a concentrate 

stream. Regeneration of the ion exchange resin depends on the specific model. Some units 

regenerate continuously while others require periodic regeneration.

Figure 8— Schematic of EDI process (from http://www.reverseosmosis.com.au/webcontent6.htm).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces ultrapure product (5-17 MOhmcm) with low organic carbon (<20 ppb)

No chemical regeneration

No resin or chemical disposal

Most models not designed for high salinity 

feed waters

Evoqua model can only handle influents 

with a TDS up to 750 mg/L

Does not directly produce a solid that can be 

dewatered

Vendors

GE Water

Veolia

Dow Water

Cal Water

SnowPure Water Technologies

Evoqua

Installations

No installations relevant to application of interest

Potential for Integration with Renewable Energy

There are no heat requirements and therefore there is minimal potential for renewable energy to 

provide a direct energy offset for this technology.

Technology Disposition

This technology is not intended for high salinity water. Therefore EDI vendors were not 

contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Electrodialysis Reversal (EDR)

EDR is an electrochemical-driven separation process. An electrical potential difference is 

applied across an anode and cathode, which drives dissolved ions to migrate through solution to 

the appropriate electrode (i.e., cations migrate towards the cathode). In between the electrodes, 

ion exchange membranes are layered alternating cation-selective and anion-selective membranes. 

Ions migrating in opposite directions can pass through one selective membrane but will be 

rejected by the next membrane of opposite selectivity. This process leads to an accumulation of 

ions in alternating layers and desalinated water between the remaining layers. This process 

produces a desalinated product stream and concentrated brine. The polarity of the electrodes 

may be periodically reversed to prevent fouling or scaling.

Figure 9—Schematic of EDR process (from 

http://www.netl.doe.gov/research/coal/crosscutting/pwmis/tech-desc/membrane).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Electrical energy input rather than thermal

Ideal for feeds with high scaling potential

Most economical for low TDS feed 

solutions

Evoqua Ionpure® VNX-Si unit has a 

nominal recovery of 68% and maximum 

feed TDS of 750 mg/L as NaCl

GE 2020 system designed for feed TDS up 

to 12,000 mg/L

Does not directly produce a solid that can be 

dewatered

Vendors

GE

Evoqua

Installations

Evoqua Ionpure® VNX-Si module treats up to 5 gpm of RO concentrate. Can be installed in 

parallel

GE 2020 EDR System produces 280 or 520 gpm depending on model

Potential for Integration with Renewable Energy

There are no heat requirements and therefore there is minimal potential for renewable energy to 

provide a direct energy offset for this technology.

Technology Disposition

This technology is not intended for high salinity water. Therefore EDR vendors were not 

contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Freeze Thaw/Evaporation

Freeze-thaw/evaporation, or FTE® by Polar Bear Water Treatment, LLC, allows for both salt 

removal from brine and disposal of water. When the ambient temperature drops below 0°C, 

brine is sprayed onto a freezing pad. As the spray freezes, an ice pile forms. Brine, with 

elevated salt concentrations and lower freezing point, drains naturally from the ice piles. The 

high-salinity brine, identified by its high electrical conductivity, is separated and pumped to a 

pond where it is later evaporated or stored for beneficial use. When the ice on the freezing pond 

melts, the purified water is pumped from the freezing pond and discharged or stored for later 

beneficial use. During the warmer months, the FTE® facility operates as a conventional 

evaporation facility. No new wastes are generated by the FTE® process and no chemical 

addition is required. Coupling the natural processes of freezing and evaporation makes the 

FTE® process more economical and effective for the treatment and disposal of brine and allows 

for year-round operation of the FTE® facility.

Figure 10—Photo of FTE® field demonstration (from http://polarbearwater.net/).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Minimal external energy requirement

Low operational cost

Potentially large land area required

Water processing capability is seasonally 

dependent

Only one vendor

Significant residual brine produced

Does not directly produce a solid that can be 

dewatered

Vendors

Polar Bear Water Treatment, LLC

Installations

Treatment of produced water, Sweetwater county, Wyoming

Potential for Integration with Renewable Energy

This process relies primarily on environmental conditions for freezing, thawing, and evaporation. 

Therefore, there is little need for the incorporation of additional renewable energy to reduce the 

energy consumption of this process.

Technology Disposition

This technology would require significant land area, require additional fluid processing, and is 

seasonally dependent. Therefore, Polar Bear Water Treatment, LLC was not contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Membrane Distillation (MD)

MD)uses hydrophobic membranes to allow the passage of water vapor but not liquid water or 

brine through the membrane. On the feed side of the membrane, water vapor generated from 

preheated brine (50 to 60°C) passes through the hydrophobic membrane and condenses on the 

permeate side. Condensation of the water vapor permeate is enhanced by heat exchange with a 

chilled concentrate stream or coolant. The condensate is collected as a combined distillate for 

fresh water use. Final brine concentrations will depend on the influent water quality and 

difference in temperature between the feed and chilled concentrate stream.

Figure 11—Schematic of MD process (from http://www.solarspring.de/index.php?id=7).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces high quality water

Concentrates brine streams

Heat source required

Scaling and corrosion from inorganics with 

some module configurations

Does not directly produce a solid that can be 

dewatered

Most systems are low feed flow (~1 to 4 

gpm)

Vendors

Solar Spring

Aquaver

Memsys

Installations

Maldivian Island of Gulhi, 1.8 gpm

Mostly bench- and pilot-scale

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

MD has not been implemented for an application of this scale and is still in development. 

Therefore, MD vendors were not contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Multi-Effect Distillation (MED)

MED uses a series of reduced pressure stages to produce water vapor and subsequently condense 

it into fresh water. Preheated influent salt water or brine enters the first stage, or effect, where it 

is evaporated by spraying it over a heat exchanger. The water vapor enters the next stage on the 

inside of a heat exchanger in which it condenses due to cool influent water contacting the outside 

of the heat exchanger. Each subsequent stage has a lower pressure than the previous one. Water 

that does not vaporize is collected as concentrated brine at the bottom of each stage. 

Concentrated brine travels through each stage until it is discarded after the final stage. Final 

brine concentrations depend on the influent water quality and the number of stages.

Figure 12— Schematic of MED process (from http://www.sidemdesalination.com/en/Process/MED/Process).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantage Disadvantages

Produces high quality water

Widely used for desalination (mainly in the 

Middle East)

Energy intensive

Readily available supply of steam required

Scaling and corrosion from inorganics

Does not directly produce a solid that can be 

dewatered

Vendors

Sidem (Veolia)

Wabag

AquaSwiss AG

IDE Technologies

Alfa Laval

Installations

Ras Laffan C IWPP, Qatar (7.6 MGD units)

Fujairah II IWPP, United Arab Emirates

(10 MGD units)

Marafiq IWPP, Saudi Arabia

(7.9 MGD units)

Zawia Derna Sussa, Libya (5.3 MGD units)

Al Hidd IWPP, Bahrain

(7.2 MGD units units)

Layyah D12/D13, United Arab Emirates 

(9.6 MGD units)

Abutaraba, Libya (3.5 MGD units units)

Ras Al Khaimah/Ajman, United Arab 

Emirates (6.0 MGD units)

Al Taweelah A1, United Arab Emirates

(4.5 MGD units)

Layyah D10/D11, United Arab Emirates 

(6.0 MGD units)

Umm Al Naar West, United Arab Emirates 

(4.2 MGD units)

Tobruk, Libya (3.5 MGD units)

Al Ghalilah, Oman (0.13 MGD units)

Priolo Gargallo, Italy (1.9 MGD units)

Jebel Dhanna, United Arab Emirates

(2.4 MGD units)

Curacao, Netherland Antilles

(3.2 MGD unit)

Trapani, Italy (2.4 MGD units)

Pantelleria, Italy (0.42 MGD units)

Hangu, Tianjin, China (52.8 MGD)

Jamnagar, Gujarat, India (42 MGD)

Jamnagar, Gujarat, India (17 MGD)
Paradox Valley Unit Brine Crystallization Technology Assessment

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Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

MED is a well-established technology and could be used to reduce the PVU brine volume. 

Therefore MED vendors were contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Multi-Effect Distillation Mechanical Vapor Compression (MED-MVC)

MED-MVC is similar to other distillation processes, except that a heat pump configuration is 

used to generate steam. Feed water enters the system and passes through a heat exchanger where 

it is preheated by the heated brine and distillate streams exiting the system. The heated feed 

solution is then sprayed on to heated coils where a fraction of the incoming stream evaporates to 

form steam. The steam passes through a compressor that increases the temperature before the 

steam enters the inside of the heat exchanger coils to act as the heat source to evaporate more 

incoming feed. The steam condenses inside the heat exchanger coils forming a distilled water 

product. Brine that does not evaporate upon first pass of the heat exchanger can be recycled or 

used in a multi-effect configuration. The main difference between this system and other 

distillation processes is that the heat source is compressed vapor formed by the incoming feed 

solution, and a separate boiler with a closed loop steam cycle is not needed. The end product is 

concentrated brine that would be sent to a crystallizer for complete water removal.

Figure 13— Schematic of MED-MVC process (from http://www.sidemdesalination.com/en/Process/MED/MED-MVC).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Higher thermal efficiency compared to 

MED

No external boiler needed to provide steam

Energy intensive evaporative process

Does not directly produce a solid that can be 

dewatered

Vendors

Sidem Veolia

Aqua Swiss

IDE Technologies

Alfa Laval

Wabag

Installations

Al Ghalilah, Sultanate of Oman

(2 x 0.13 MGD)

Pantelleria, Italy (2 x 0.42 MGD)

Sardinia, Italy (4.6 MGD)

Turkmenbashi, Turkmenistan

(2 x 0.79 MGD)

Puerto Coronel, Chile (0.51 MGD)

Nueva Ventanas, Chile (2 x 0.3 MGD)

Tocopilla, Chile

(0.16 and 0.096 MGD units)

Emlichheim Oil Field, North Germany

(0.32 MGD)

Tutuka Power Station, South Africa

(0.32 MGD)

Burrup, Peninsula, Australia (0.95 MGD)

CHP, Taba, Egypt (0.53 MGD)

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

MED-MVC is a well-established technology and could be used to reduce the PVU brine volume. 

Therefore MED-MVC vendors were contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

41

Multi-Effect Distillation Thermal Vapor Compression (MED-TVC)

MED-TVC is similar to MED-MVC desalination with one modification. A thermo-compressor 

is used rather than a mechanical compressor to generate steam to feed to the evaporator. 

Medium or low pressure motive steam generated by a boiler is fed to the thermo-compressor via 

a sonic nozzle. The expansion of this steam sucks in water vapor evaporated from the brine. A 

shock wave within the compressor increases the pressure of the steam before exiting the 

compressor. This steam is used as the heat source in the heat exchanger bundles to evaporate 

more liquid from the brine. The unit produces distilled water and concentrated brine. The 

concentrated brine would then be fed to a crystallizer to produce a solid salt product.

Figure 14— Schematic of MED-TVC process (from http://www.sidemdesalination.com/en/Process/MED/MED-TVC/).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Higher thermal efficiency compared to 

MED

Reduced inorganic scaling risk

Efficient use of latent heat from evaporated 

brine with a ‘heat pump’ design

High gain output ratios (upwards of 17 kg 

distillate produced per kg of motive steam 

fed)

Energy intensive evaporative process

Requires a boiler in addition to the thermocompressor to produce motive steam

Does not directly produce a solid that can be 

dewatered

Vendors

Wabag

Sidem/Veolia

Installations

Suralaya, Java, Indonesia (1.59 MGD)

Benghazi, Libya (1.27 MGD)

Pertamina, Indonesia (1.32 MGD)

Tobruk, Libya (3.5 MGD)

Layyah, United Arab Emirates (2 x 6 MGD)

Ras Laffan, Qatar (10 x 6.3MGD)

Fujairah, United Arab Emirates

(12 x 8.33 MGD)

Marafig, Saudi Arabia (27 x 6.59 MGD)

Zawia Derna Sussa (8 x 5.3 MGD)

Al Hidd (10 x 6 MGD)

Layyah D12/D13, United Arab Emirates

(2 x 8 MGD)

Abutaraba, Libya (3 x 3.4 MGD)

Ras Al Khaimah, United Arab Emirates

(3 x 6.0 MGD)

Al Taweelah, United Arab Emirates

(14 x 3.77 MGD)

Layyah D10/D11, United Arab Emirates

(2 x 6.0 MGD)

Umm Al Naar West (2 x 4.2 MGD)

Tobruk, Libya (3 x 3.5 MGD)

Al Ghalilah (2 x 0.13 MGD)

Jebel Dhanna (2 x 2.4 MGD)

Curacao, Netherland Antilles

(1 x 3.17 MGD)

Trapani, Italy (2 x 2.37 MGD)
Paradox Valley Unit Brine Crystallization Technology Assessment

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Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

MED-TVC is a well-established technology and could be used to reduce the PVU brine volume. 

Therefore MED-TVC vendors were contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Multi-Stage Flash Distillation (MSFD)

MSFD uses a series of reduced pressure stages to flash, or generate water vapor, from preheated 

influent salt water or brine. Generated water vapor condenses on the outside of condenser tubes 

that also act as influent water piping. Condensed water vapor is collected in trays as a combined 

distillate for fresh water use. Increasingly concentrated brine then travels to subsequent stages 

where flashing is enhanced using decreasing pressures until it is discarded after the final stage. 

Final brine concentrations depend on the influent water quality and the number of stages.

Figure 15— Schematic of MSFD process (from http://www.sidemdesalination.com/en/Process/MSF/).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces high quality water

Widely used for desalination, many 

installations in the Middle East

Energy intensive

Readily available supply of steam required

Scaling and corrosion from inorganics

Does not directly produce a solid that can be 

dewatered

Most existing installations for flows larger 

than 0.43 MGD

Vendors

Sidem (Veolia)

Wabag

Installations

Al Taweelah A, United Arab Emirates (8.8 MGD units)

Umm Al Naar East & West, United Arab Emirates (7.3 MGD units) 

Al Khobar 2, Saudi Arabia (7.0 MGD units)

Abu Dhabi 1, United Arab Emirates (4.0 MGD units)

Zliten, Libya (2.6 MGD units)

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

MSFD is a well-established technology and could be used to reduce the PVU brine volume. 

Therefore MSFD vendors were contacted for additional information.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Pellet Softening

Pellet softening uses seeding nuclei or ballast, typically fine sand, to initiate precipitation and 

settling of minerals such as calcium carbonate. The technology is widely used for softening but 

may also have application for concentrated brines. After raising the pH using lime or caustic 

soda, dissolved solids will precipitate onto the sand ballast until the combined specific gravity is 

high enough to cause the newly formed pellet to settle. Pellets are then removed from the 

fluidized bed system and dried prior to disposal. As pellets are removed, new sand is 

periodically added to the system.

Figure 16— Schematic of a pellet softening process (from 

http://www.chinodesalter.org/DocumentCenter/View/23).
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Produces high quality water

Widely used for desalination, many 

installations in the Middle East

Energy intensive

Readily available supply of steam required

Scaling and corrosion from inorganics

Does not directly produce a solid that can be 

dewatered

Most existing installations for flows larger 

than 0.43 MGD

Vendors

Rwb

Veolia

Installations

Rouessé-Fontaine, France, (2015), 880 gpm

Mandelieu-La Napoule, France, (2014), 

6605 gpm

Montsoult, France, (2014), 1233 gpm

Bruz, France, (2013), 1211 gpm

Montry, Marne et Morin, France, (2012), 

1277 gpm

Puchay, France, (2011), 572 gpm

Bouil de Chambon, France, (2011),

2202 gpm

Courcelles-la-Forêt, France, (2010),

705 gpm

Cluses, France, (2009), 1101 gpm

Sète, France, (2008), 5280 gpm

Emmerin-Arbrisseau, France, (2007),

5504 gpm

Torcy, France, (2003), 1651 gpm

Beaune, France, (2003), 2202 gpm

Ijzeren Kuilen, Netherlands, (2000),

10,040 gpm

Malmö, Sweden, (1999), 24,400 gpm

Val-de-Reuil, France, (1994), 3960 gpm

Leiduin, Netherlands, (1987), 55,042 gpm
Paradox Valley Unit Brine Crystallization Technology Assessment

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Potential for Integration with Renewable Energy

The potential for renewable energy to offset power requirements for this process is low.

Technology Disposition

Pellet softening would remove some dissolved salts from the PVU brine but mostly divalent ions 

such as calcium, leaving sodium chloride still dissolved. Pellet softening also does not reduce 

brine volume. Therefore pellet softening vendors were not contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Wind Aided Intensified Evaporation (WAIV)

WAIV uses high surface area materials that are wetted with concentrated brine to increase 

evaporation volumes. At the surface of evaporation ponds, wind velocities are slower and the 

evaporation efficiency decreases with increasing pond area. Volcanic rock, geotextiles, and 

nettings have been used to provide the higher surface area while still allowing wind to pass 

through WAIV units or arrays. Although the evaporation rates per unit area are less than pan 

evaporation due to tight array arrangements, cumulative evaporation volumes can be much 

greater than pan evaporation. Therefore, WAIV units can have a much smaller footprint than 

evaporation ponds.

Figure 17— Schematic of the WAIV process (from http://www.lesico-cleantech.com/wpcontent/uploads/Lesico-CleanTech-Report.pdf). 1 holding pond, 2 – feed pump, 3 – wetted 

evaporation surfaces, 4 – impervious surface to allow brine to flow back to holding pond.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Advantages Disadvantages

Low energy requirements

Smaller footprint than conventional 

evaporation ponds

Does not directly produce a solid that can be 

dewatered

Still requires larger areas

Still requires small (evaporation) holding 

pond, from which solids will have to be 

removed

Limited full-scale applications

Vendors

Lesico CleanTech

Installations

Desalination plant at General Motors in Ramos Arispe, Mexico (pilot-scale)

Mineral brines, Dead Sea Works, Israel (pilot-scale)

Produced water management for Santos, Australia (pilot-scale)

Pettavel winery brackish water reverse osmosis plant, Melbourne (pilot-scale)

Copping landfill, Tasmania (pilot-scale)

Mekorot (Israel’s national water company) brackish water reverse osmosis plant (pilot-scale)

Mineral processing, Chile (pilot-scale)

Potential for Integration with Renewable Energy

Solar thermal or geothermal heat could be used to offset heat requirements.

Technology Disposition

Although evaporation ponds are already being considered under another project, the footprint of 

WAIV is smaller than conventional evaporation ponds. Therefore Lesico CleanTech was 

contacted.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Technology Assessment

Information request sheets (Appendix A) were sent to vendors of the technologies deemed 

relevant and potentially viable for the PVU. Rather than requesting vendors to provide 

additional information about specific technologies identified in the section titled Preliminary 

Technology Screening, vendors were requested to identify a technology appropriate for the PVU 

based on their company’s technology portfolio, knowledge, and field experience. It was stated in 

the information request that Reclamation is seeking additional information regarding potential 

solutions for the treatment/volume reduction of concentrated brine and/or byproducts for the 

existing PVU.

Background information including water quality was provided, but mainly the requests focused 

on acquiring the following information from the vendors:

Process/Technology description

Land requirements

Power requirements

Chemical requirements

Labor requirements

Capital cost

Solids water content

Fresh water production

Byproducts

Fate of H2S

Solar thermal or geothermal potential

Demonstrated applications

Pilot testing potential

Environmental impacts
Paradox Valley Unit Brine Crystallization Technology Assessment

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It was also stated that the information they provided would be used for planning purposes or 

preliminary level cost estimates of ±50 percent. Based on the preliminary screening in the 

section titled Preliminary Technology Screening, 18 technology vendors were contacted, of 

which 6 provided substantial responses. Vendor responses are not included in this version of the 

report, as these responses contained sensitive and proprietary information.
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Technical Comparison

All responsive vendors proposed a thermal crystallization process to separate water from salt. 

The common thread between all proposed technologies is that heat input vaporizes water and 

crystallization processes occur when the brine becomes saturated with respect to specific solids 

(e.g., sodium chloride, calcium sulfate, etc.). The slurry is then dewatered prior to disposal. The 

means by which thermal energy is provided varied between vendors. 

No salt recovery process inherently handles H2S at the same time. Each vendor recommended a 

separate pretreatment step that would strip or oxidize H2S. Since H2S is a dissolved gas in 

solution, some vendors proposed strippers to transfer H2S from the liquid phase to the vapor 

phase by increasing the brine temperature and passing it through a stripping tower that injects 

steam at the bottom. The gas-liquid separation occurs as the liquid phase travels down the 

column. Volatilized H2S is usually passed through a sulfur recovery unit to prevent direct 

emission to the atmosphere.

Other vendors recommended methods that oxidize the sulfur containing compounds by either 

chemical (ozone) or thermal processes. These reduction-oxidation reactions would convert the 

H2S to either elemental sulfur (S0) or sulfate (SO4

2-

), both of which would be separated as solids 

in the crystallization process. These responses show that there are multiple approaches to 

addressing the H2S content and that further investigation to identify the most effective H2S

control strategy is needed through additional testing.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Economic Comparison

Approach and Assumptions

Based on the responses received from vendors, a preliminary economic analysis was conducted 

to determine the present value (PV) cost of constructing and operating a treatment process that 

produces a solid salt product for landfill disposal. If a vendor provided a range of cost estimates, 

the PV was calculated using the low and high estimates.

All PVs were based on vendor estimates and a number of assumptions, and can only be 

considered preliminary. First, the assumed project lifetime was 50 years. To calculate the PV of 

all operating costs, the inflation rate of O&M expenses was assumed to be equal to the discount 

rate. Landfill disposal costs were not included in the calculations.

The capital and O&M costs provided by the vendors were used under the assumption that they 

are accurate within ±50 percent. It was assumed that vendors which reported O&M costs 

included a labor estimate. Some vendors did not provide estimated O&M costs. For these 

vendors, O&M costs were estimated based on the electricity costs to meet the power 

requirements at a rate of $0.08/kWh (U.S. Energy Information Administration, 2016) and labor

costs of $100,000 per operator per year (including salary and overhead) with three shifts per day. 

Chemical costs were not included and assumed small compared to energy costs and compared to 

the uncertainty associated with other operating costs.

Results

A summary of the PV calculation is shown in table 4. The estimated PV costs for the 

technologies varied considerably, suggesting that further investigation, primarily bench- and 

pilot-scale testing, is needed to better refine the relative cost effectiveness of each technology. 

Changing the assumption that the inflation rate of O&M expenses is equal to the discount rate 

could have a significant impact on the calculations. If the inflation rate of O&M expenses is 

greater than the discount rate, the technologies with higher capital cost to O&M cost ratios would 

become relatively less expensive when compared with technologies with lower capital cost to 

O&M cost ratios. The opposite would be true if the inflation rate of O&M expenses is less than 

the discount rate. As stated, these process costs were inherently uncertain and should only be 

used to rationalize further investigations and process testing to refine process economics.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Table 4 — PV comparison of Brine Treatment Processes for the PVU.

Technology

Vendor

Vendor Estimate Present Value (PV)

Low

Flow

High

Flow

Total

($M)

Capital

($M)

O&M

($M/yr)

Capital

($M)

O&M

($M/yr) Low High

Vendor A 30 3.8 - - 220 -

Vendor B 221 3.5 - - 197 -

Vendor C 30 0.64 39 0.86 62 82

Vendor D 14 5.3 - - 279 -

Vendor E 15 4.3 20 4.3 230 235

Vendor F 24 2.1 - - 129 -

1 Because Vendor B only provided equipment and engineering capital costs at $7.4M, it was assumed this 

represented roughly a third of the total installed capital cost.
Paradox Valley Unit Brine Crystallization Technology Assessment

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Preliminary Renewable Energy Assessment

Because of the large power requirement for the brine minimization technologies described in this 

report, offsetting the power requirement with renewable energy will be difficult but may offset 

electrical or thermal energy needs. However, renewable energy would provide some level of 

protection from escalating energy costs which could become a factor over a 50-year project life. 

The potential for renewable energy to offset a significant fraction of the process requirements 

will require more in-depth research and testing specific to the PVU site. The following section 

summarizes the energy potential from photovoltaic solar, solar thermal, and geothermal for the 

PVU.

Photovoltaic Solar

Photovoltaic solar cells convert solar irradiance to electricity but require large footprints due to 

low cell efficiencies. Photovoltaic solar may be used to offset some of the power consumed by 

the chosen brine treatment technology. The PVU is located in an area with moderate 

photovoltaic solar resources as shown in figure 18 from the National Renewable Energy 

Laboratory (NREL). To get an estimate of the land requirements for photovoltaic solar at the 

PVU, NREL’s PVWatts® calculator was used (pvwatts.nrel.gov). Near Bedrock, Colorado, an 

area of approximately one acre corresponds to a direct current (DC) system size of 600 kW. In 

PVWatts® the following assumptions were specified:

• Standard module (crystalline silicon, 15% efficient, glass cover)

• Fixed, open rack, ground-mounted panels

• 14% system losses (soiling, shading, snow, etc.)

• DC to alternating current (AC) efficiency of 96%

• 20° panel tilt

• 180° azimuth (south facing)

According to PVWatts® a 1 acre solar array would generate approximately 1,000 MWh/yr (AC) 

near Bedrock, Colorado. A crystallization system would require approximately 44,000 MWh/yr 

(estimated from Technology Assessment section). Therefore, for photovoltaic solar panels to 

offset 50 percent of the energy required, a 22 acre array would be required.

Difficulties in using photovoltaic solar for energy-intensive processes are further illustrated by 

the recently constructed Carlsbad desalination plant in southern California (Poseidon 

Engineering, 2008). Preliminary plans had a 50,000 ft2 treatment plant building mounted with 

photovoltaic solar panels. The photovoltaic solar system was expected to generate 

approximately 777 MWh/yr of electricity with a net carbon footprint reduction of 275 tons of 

CO2 per year. The total power use for the plant was expected to be 274,400 MWh/yr with a 

carbon footprint of 88,147 tons of CO2/yr. The portion of the power offset due to solar was 

expected to be less than 1 percent. The anticipated cost of power generation using the 

photovoltaic solar system was calculated to be $0.50/kWh, or about five times more expensive 

than the power supplied from the electric grid. This does not rule out the use of photovoltaic 

solar at the PVU, but energy savings may not overcome the large footprint and/or capital cost 

requirements.
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Figure 18— NREL map of photovoltaic solar resource potential 

(http://www.nrel.gov/gis/images/eere_pv/national_photovoltaic_2012-01.jpg). Approximate project 

location indicated by yellow circle.
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Solar Thermal

Thermal energy from solar collectors can be used to preheat feed streams for thermal processes, 

which can offset energy requirements from other conventional heat sources (e.g., power plant 

waste heat and steam generation). Parabolic troughs or mirrors are examples of solar collector 

technologies. The PVU is located in an area with moderate concentrating solar resource 

availability as shown in figure 19 from NREL. Because many of the potential technologies use 

crystallizers to evaporate water from preheated brine, there is a potential for direct use of solar 

thermal energy as a heat source to reduce conventional energy requirements. One vendor

identified solar thermal as a potential opportunity to incorporate renewable energy.

Figure 19— NREL map of concentrating solar resource potential 

(http://www.nrel.gov/gis/images/eere_csp/national_concentrating_solar_2012-01.jpg). 

Approximate project location indicated by yellow circle.
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Geothermal

Geothermal power generation consists of a geothermal resource well, power generation 

equipment, and an injection well. Hot geothermal fluid is pumped up the production well, 

processed for energy conversion, and expanded through a turbine to power an electric generator. 

The used geothermal fluid is then pumped back into the geothermal reservoir. There are four 

different types of geothermal power plants; dry steam, single-flash, double-flash, and binary. 

Each geothermal source is unique and suited to a particular process design. Any of the designs 

can offset electrical or thermal energy requirements for the PVU. The electricity generated can 

be used to run pumps and other process equipment whereas thermal energy could be used to 

preheat brine. The PVU is located in an area with minimal geothermal gradient according to the 

interpretive map shown in figure 20. The map from NREL in figure 21 shows the PVU in an 

area with moderate geothermal potential. Therefore further testing would be needed to 

determine the exact capabilities of a geothermal well at the PVU location. Similar to solar 

thermal incorporation, an economic analysis would be needed to justify if the increased capital 

costs of geothermal outweigh the reduced operating costs.
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Figure 20— Interpretive geothermal gradient map of southwest Colorado (Berkman and 

Watterson, 2010). Approximate project location indicated by black circle.
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Figure 21— NREL map of geothermal resource potential 

(http://www.nrel.gov/gis/images/geothermal_resource2009-final.jpg). Approximate project 

location indicated by yellow circle.
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Technology Testing

In the initial vendor request, there was an inquiry about vendor capabilities for pilot testing. 

After reviewing responses, a follow-up request was sent to inquire about bench-scale testing. A 

wide range of testing options exists with each requiring different brine quantities and costs and 

resulting in a varying testing outcomes.

Bench-scale crystallization tests aim to understand the thermodynamic aspects of the 

crystallization process and mass balance on chemical constituents. Many vendors indicated that 

they could quantify boiling point rise on the brine, which is an important parameter for sizing a 

vapor compression unit and determining energy demands. Dissolved salt increases the boiling 

point of water, and the temperature increase depends on the type and quantity of salt present. 

Another common outcome of the bench-scale testing, identified in the responses, is 

characterization of condensate. This step determines the treated water quality, which is 

important for determining discharge or disposal options for the treated water.

Two vendors stated that physical crystal properties could be investigated, which is important for 

determining solids bulk density. Two vendors stated that their bench-testing would include an 

analysis of solids dewatering. The final water content is important for transportation costs to the 

landfill and potentially volume as well. Only one vendor recommended bench-scale testing of a 

chemical H2S oxidation process.
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On-Site Demonstration Testing Recommendations

On-site testing at a larger scale is recommended to demonstrate operation of one or more brine 

management technologies that reduce a portion of the PVU brine to a solid waste product 

suitable for landfill disposal. Demonstration testing would provide the information necessary to 

fully evaluate implementation at the full-scale and long-term potential of the process for brine 

management at the PVU; including, but not limited to the following: process operation 

requirements, power requirements (including potential for renewable energy), chemical 

requirements, process consumables, labor requirements, final solid product quantity and 

composition, and life-cycle costs. Landfill disposal would also have to be part of demonstration 

testing.

The results of this preliminary assessment did not differentiate the various technologies and 

equipment manufacturers on the basis of either performance or cost. Therefore, it is 

recommended that on-site testing services be obtained through an open bidding process. 

Furthermore, it is recommended that this bidding process be open to all interested parties, 

including those that were not included in this preliminary assessment. In the proposal, interested 

parties should provide sufficient supporting documentation such as test plans, quality assurance 

and quality control plans, and examples of installations currently using the proposed 

technologies. This approach would allow Reclamation to evaluate each equipment manufacturer 

and select one or more to perform demonstration testing at the PVU.

The chosen equipment supplier or contractor must demonstrate relevant experience and supply 

sufficient information concerning their process such that Reclamation can evaluate the potential 

of the process to meet the needs of the PVU project. Before testing begins, the contractor should 

provide a test plan to Reclamation for review and comment. The test plan should include 

equipment operating conditions (flow rates, pressures, chemical composition, etc.) and describe 

the type and frequency of data to be collected. In addition to process operating conditions, data 

should also be gathered on chemical, electrical, and thermal energy requirements, as well as 

other process consumables, such as cartridge filters. Demonstration testing should be conducted 

for a time period sufficient to meet the objectives described above.

After testing is complete, the testing contractor should provide a report that fully documents all 

testing conducted in accordance with the approved test plan. At a minimum, the report should 

include projected process operational requirements, power requirements, chemical requirements, 

labor requirements, final product composition, and capital and operation, maintenance, and 

replacement costs. Reclamation should also be provided an electronic copy of all data collected 

during the testing.
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References

Berkman, FE, and Watterson, NA. 2010. Interpretive Geothermal Gradient Map of Colorado.

Colorado Geological Survey, Denver, Colorado.

Poseidon Engineering. 2008. Carlsbad Seawater Desalination Project: Energy Minimization and 

Greenhouse Gas Reduction Plan. December 10, 2008.

http://www.sdcwa.org/sites/default/files/files/environmental-docs/city-of-carlsbad/2-

energy-minimization-greenhouse-gas-reduction-plan-Dec2008.pdf. Accessed March 1, 

2016.

U.S. Energy Information Administration. 2016. Monthly Energy Review. 

https://www.eia.gov/totalenergy/data/monthly/pdf/sec9_11.pdf. Accessed March 30, 

2016.
1

Appendix A - Vendor Information Request 

Sheet