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AIChE – Central FloridaSand Key, FL Conference

June 10, 2006

Continuous Ion Exchangefor

Fertilizer & PhosphateApplications

Richard S. DennisSeparation Products Manager

Tampa, FL

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IntroductionFertilizer/Phosphate Applications

IntroductionIntroductionFertilizer/Phosphate ApplicationsFertilizer/Phosphate Applications

Continuous Ion Exchange – The “Higgins Loop”Specialized Applications for “Non Water” Processes Challenging Chemical Separations for Concentrated SolutionsPurification, Product Recovery & Chemical Metathesis

Fertilizer & Phosphate InstallationsNH3 & NO3 Recovery from Ammonium Nitrate Plant WastewaterPotassium Nitrate ProductionPhosphoric Acid PurificationPotassium Carbonate Production

Presentation OutlineIon Exchange BasicsHiggins Loop™ InstallationsPrinciples of OperationApplications: Potassium Nitrates & Phosphates

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Severn Trent ServicesThe Company

Severn Trent ServicesSevern Trent ServicesThe CompanyThe Company

Environmental Services CompanyOver $600 Million in Annual US Sales5,000 Employees WorldwideHeadquarters - Fort Washington, PA Part of Severn Trent Plc - Birmingham, U.K.

Separations: Filtration, Membranes & Biotreatment SystemsDisinfection Products & ProcessesEnvironmental Laboratory TestingOperations & Maintenance ServicesFiltration & Membrane SystemsChemical Separation & Water Purification Systems

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Ion ExchangeBasic Information

Ion ExchangeIon ExchangeBasic InformationBasic Information

Resin StructureSpherical Porous Beads – Organic Polymers16-50 Mesh Range (0.3-1.0 mm Ø)15-25% Pore Volume + 40-50% Void Space

Cation & Anion FunctionalityCation Resins: Sulfonated (R-SO3

-) to Hold CationsAnion Resins: Aminated (R-N-(CH3)x

-) to Hold Anions

Maximum Resin Loadings (Typical)Key: Valence, Molecular Weight & Resin Site CapacitiesK – 74 gpl; PO4 – 53-106 gpl, NH4 – 34 gpl

Resin Rinsing – Between Adsorption & Regeneration2-5 Bed Volumes to Recover Product or Minimize ContaminationProduct / Regenerant Dilution

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Continuous Ion ExchangeFeatures & Benefits

Continuous Ion ExchangeContinuous Ion ExchangeFeatures & BenefitsFeatures & Benefits

Separation Process PrinciplesContinuous & Countercurrent ProcessResin Flow Controlled with Process LiquidsBed Depth Limited only by Active Mass Transfer Zone (MTZL)Fresh Resin Moved Frequently into These “I-X” Zones

Ion Exchange BenefitsResin Working Capacity & Ion Selectivity OptimizedHigh Regeneration Product Strenghs & Low VolumesMore Efficient Regenerant UsageLow Liquid/Resin Treatment Ratios (<1) – Remove up to 150,000 ppm

Resin Rinsing BenefitsCountercurrent Contacting Minimizes Water - <1 Bed VolumeIncreased Product Recovery & Minimum Dilution

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Higgins Loop™Continuous Ion Exchange

Higgins Loop™Continuous Ion Exchange

BACKGROUNDBACKGROUND

Invented by Irwin Higgins in 1951 at ORNL (AEC)Focus on Radioactive Ion Separations with I-X Resins

Designed for Continuous, Selective Ion Separations

Applies Countercurrent Liquid/Resin Contacting to Ion Exchange

Commercialized in 1955; Acquired by Severn Trent (Tetra) in 1991

Alternative to Solvent Extraction, Fixed Bed I-X & Precipitation

Over 5 Decades of Experience

CCIXTM - Continuous Countercurrent Ion ExchangeReferenced as the “Higgins Contactor” in Handbooks

Chemical, Mining, Nuclear & Municipal Industries

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LOOP CONFIGURATIONLOOP CONFIGURATION

Higgins Loop™Higgins LoopHiggins Loop™™

C

D A

B

Pulse - Controls Resin Flow through Loop

Backwash

Adsorption - Ion Loaded onto ResinAdsorption

Regeneration - Ion Desorbed from ResinBackwash - Fines & Solids Removal

Cylindrical Resin Loop4 Vessels Separated by Loop Valves

Countercurrent FlowsResin Moves Clockwise Intermittently

Res

inLi

quid

s

Feed & Regen Flows-Counterclockwise

Pulse

ButterflyLoop

Valves

Regeneration

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Nalco Chemical Company – 1996Colloidal Silica Products Producer

Process – Silicic Acid ProductionReplaces Fixed Bed I-X SystemProduces 9% H2SiO3 from 12% Na2SiO3Cation Exchange Between H+ & Na+

Remove 19,000 ppm Na from SolutionLiquid/Resin Treatment Ratio – 2.5

System Capacity & Size42”-Ø Loop – 550 ft3 Resin Inventory50,000 lbs/Day SiO2 Product – 60 gpm

PerformanceImproved SiO2 Recoveries from 85% to 96%$1.1 Million Annual Savings

Process ApplicationsChemical MetathesisProcess ApplicationsProcess Applications

Chemical MetathesisChemical Metathesis

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MEADWestvaco Chemical – 1998Granular Activated Carbon Producer

Process – Phos Acid PurificationRemoves Cations from Activation AcidCation Exchange Between H+ & Ca2+/ K+

Removes over 400 ppm from SolutionSystem Capacity & Size

24”-Ø Loop w/ 36”-Ø Acid Treatment Zone 480 ft3 Resin Inventory60 gpm 40% H3PO4 Capacity

Performance2 “Folded” Loops in Operation for 8-20 Yrs

Process ApplicationsAcid Purification

Process ApplicationsProcess ApplicationsAcid PurificationAcid Purification

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Vicksburg Chemical Co – 1994Potassium Chemicals Producer

Process: Potassium Carbonate Product’nPotash & Ammonium Carbonate FeedsCation Exchange Between K+ & NH4

+

70 gpl K Resin Loading (1.8 equ/l)System Capacity & Size

Two 54”-Ø Loops – 2,500 ft3 Resin Inventory25,000 Tons/Yr “K-Carb” Production70 gpm Capacity

PerformanceProduces 18+% K2CO3 Solution <50 ppm Cl in Final Product93% K Recovery from KCl

Process ApplicationsChemical MetathesisProcess ApplicationsProcess Applications

Chemical MetathesisChemical Metathesis

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EMIT Water Discharge TechnologyNatural Gas Produced Water Treatment

Process – Na Removal from Produced H2OCoal Bed Methane Extraction ApplicationRemoves Na from High NaHCO3 WaterCation Exchange Between H+ & Na+

HCO3 forms CO2 for Aeration/TDS ReductionSystem Capacity & Size

12-24”-Ø Loop – 80-350 ft3 Resin Inventory6-25K Barrels/Day of Water TreatedOver 4.0 MGD Treatment Capacity - 2005

PerformanceMakes Water Suitable for DischargeReduces SAR, CO3 & TDS

Process ApplicationsWater Purification

Process ApplicationsProcess ApplicationsWater PurificationWater Purification

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Modular DesignModular Design

Higgins Loop™ I-X Systems24”-Ø EMIT Loop

Higgins LoopHiggins Loop™™ II--X SystemsX Systems2424””--ØØ EMIT LoopEMIT Loop

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Higgins Loop™CBM Water Na Removal

Higgins LoopHiggins Loop™™CBM Water Na RemovalCBM Water Na Removal

30% HCl

Spent Regen

PulsePump

ResinTrap Tank

Clean Water

Dilution H2O

Raw Water

D A

B

C

II--X SYSTEM X SYSTEM CONFIGURATIONCONFIGURATION

System ComponentsLoop & Cation Resin4 Loop Valves8 Process ValvesFlow & Conductivity MetersPulse Pump & Resin TankBrine Dilution & Feed UnitPLC Controller

B

Backwash

Pulse

Adsorption

Rinse

Regeneration

HClDilution& Feed

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NORMAL SERVICENORMAL SERVICE

Higgins Loop™Principles of Operation

Higgins LoopHiggins Loop™™Principles of OperationPrinciples of Operation

Na ADSORPTION

R-H + Na+ R-Na + H+

HCl Regeneration

R- Na + HCl R-H + NaCl

Clean Water Contains <20 mg/L Na

15% HCl Used for Regeneration[NaCl] in Spent Regen - 20%

HCl Acid

Spent Regen

Clean Water

Raw Water

D A

B

C

Adsorption

Regeneration

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Higgins LoopHiggins Loop™™ OperationOperation

RESIN PULSING RESIN PULSING -- AA

Initial PositionResin Volume in Pulse Vessel

ActionProcess Flows are Stopped

Regen Interfaces are Normal

Loop Valves B, C & D Open

Pulse Water Flow is StartedNaCl Salt

Spent Regen

Clean Water

Dilution H2O

Raw Water

C

B

AD

C

B

D

Pulse Water

ResinPulse

Water/RegenInterfaces

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Overflow

RESIN PULSING RESIN PULSING -- BB

Final PositionResin Pulsed Below B Valve

ActionPulse Water Flow is Stopped

ResinPulse

Interfaces Move with Resin

Loop Valves B, C & D Close

Pulsing Time - 20 Seconds

Pulse Water

DC

B

A

C

B

D

Water/RegenInterfaces

Higgins LoopHiggins Loop™™ OperationOperation

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SERVICE CYCLESERVICE CYCLE

ActionProcess Flows Restarted

Pulse Vessel Recharged withResin - A Valve Opens

Resin is Backwashed

B’wash H2O

Overflow

A

Clean Water Rinses InterfacesBack to Normal

Pulse Water Displaced fromRegen Vessel

Spent Regen Effluent Flows

C

Dilution H2O

Clean Water

Raw Water

HCl Acid

A

B

Water/RegenInterfaces

Dilution H2O

AD

Spent Regen

Higgins LoopHiggins Loop™™ OperationOperation

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Fertilizer ProductionKNO3 Production from KCl & HNO3

Fertilizer ProductionKNO3 Production from KCl & HNO3

Process Objectives

Premium Cl-free Fertilizer Directly from PotashConcentrated KNO3 Solution Requiring Minimum EvaporationConcentrated Cl Solution for HCl/CaCl2 Byproduct Recovery

KCl + R-H ➨ R-K + HCl (Byproduct)Resin Regeneration:

Salt Production:

where “R-” is a cation resin site

Ion Exchange Chemistry

HNO3 + R-K ➨ R-H + KNO3 (Product)

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Higgins Loop™KNO3 ProductionHiggins Loop™

KNO3 Production

430 ft3 of Cation ResinAvg Resin Rate – 3.1 ft3/MinResin Loading – 70 gpl K36”-Ø Higgins Loop25 TPD KNO3 Capacity32% KNO3 with <50 ppm Cl

31.8% KNO3

Displ’d H2O

26%KCl

Water

24% HNO3

Pulse Pump

11.1 GPM25 TPD 100% KNO3

12.3% K; 4.4% N<20 PPM Cl

Potassium Nitrate

11.0 GPM20.3 TPD KCl13.6% K

HCl

To CaCl2 Conv’n12.2 GPM12.0% Cl

10.6 GPM17.4 TPD HNO3

K-loaded ResinOrange Beads

H-loaded ResinGreen Beads

A

C

D

B

Regeneration

Production

Backwash

Wash

Res

in

Pulse

Rinse

ResinTrapTank

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Higgins Loop™KH2PO4

Ion ExchangerH3PO4

KCl

Phos Acid Feed7.5 GPM; 28% P2O516.8 TPD P2O5

Potash Feed6.3 GPM; 26% KCl11.6 TPD KCl

MKP I-X Product7.9 GPM

27% P2O5; 9% K

HDS™ RegenPrecipitation

SystemCaCl2

Byproduct CaCl2to Evaporation & Sale8.6 TPD CaCl2

Spent KCl Regen8 GPMAl, Ca, Cd, H, Fe, K & Mg

CaO

Lime for Spent Regen3.5 TPD CaO

HDS™ MKPPrecipitation

System

MKPEvaporation &

DryingPurified MKP

7.1 GPM14,000 PPH

MKP Product17.6 TPD KH2PO4

KOH

1.0 TPD KOH

38.1 TPD

MKP

CaO

Water Vapor

HDS™ SludgeDewatering& Washing

Solids

HDS™ SludgeFe & Al PO4SO4, SiF6 & F

HDS™ Sludge

4.1 TPD Solids

Mono Potassium Phosphatefrom KCl & Wet Process H3PO4

Mono Potassium Phosphatefrom KCl & Wet Process H3PO4

Ion ExchangeProduction

Purification& Refining

ByproductTreatment

Waste MetalsHandling

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Mono Potassium PhosphateProcess Economics Mono Potassium PhosphateProcess Economics

Operating Factor of 300 Days/Yr or 82.2% TPY 100% Unit $ Total $________ _____ ______ Product Streams

Mono Potassium Phosphate 100.0% 5,277 $450 $2,374,824 Calcium Chloride 38.0% 2,481 $200 $496,260

Total Revenues $2,870,000 Chemical Usages

Phosphoric Acid (as P2O5) 28.0% 5,036 $120 $604,351 Potassium Chloride 100.0% 3,470 $120 $416,352 Potassium Hydroxide 45.0% 290 $500 $145,103 Lime (Calcium Oxide) 100.0% 778 $70 $54,475

Subtotal $1,220,281 Utilities

Evaporation Steam (Tons) 100.0% 15,454 $10 $154,541 Cation Resin Addition (Ft3) N/A 37.50 15.0% $120 $4,500 Electrical Power (MWH) N/A 0.90 $80 $21,600

Subtotal $180,641 Fixed Costs

Operating Labor N/A 24.0 Hrs/Day $30 $216,000 Maintenance 2.5% of Capital Equip't $37,125 Depreciation on Total Capital of $2,673,000 10.0% of Capital $267,300

Subtotal $520,425

Total Costs $1,920,000 Investment Summary

Return on Investment 36% Annual Gross Profit: $950,000

Operating Factor of 300 Days/Yr or 82.2% TPY 100% Unit $ Total $________ _____ ______ Product Streams

Mono Potassium Phosphate 100.0% 5,277 $450 $2,374,824 Calcium Chloride 38.0% 2,481 $200 $496,260

Total Revenues $2,870,000 Chemical Usages

Phosphoric Acid (as P2O5) 28.0% 5,036 $120 $604,351 Potassium Chloride 100.0% 3,470 $120 $416,352 Potassium Hydroxide 45.0% 290 $500 $145,103 Lime (Calcium Oxide) 100.0% 778 $70 $54,475

Subtotal $1,220,281 Utilities

Evaporation Steam (Tons) 100.0% 15,454 $10 $154,541 Cation Resin Addition (Ft3) N/A 37.50 15.0% $120 $4,500 Electrical Power (MWH) N/A 0.90 $80 $21,600

Subtotal $180,641 Fixed Costs

Operating Labor N/A 24.0 Hrs/Day $30 $216,000 Maintenance 2.5% of Capital Equip't $37,125 Depreciation on Total Capital of $2,673,000 10.0% of Capital $267,300

Subtotal $520,425

Total Costs $1,920,000 Investment Summary

Return on Investment 36% Annual Gross Profit: $950,000

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Process Development & DesignApproach

Process Development & DesignApproach

Project QualificationProduct Market, Pricing, Quality, etc.Preliminary System Sizing, Estimate & EconomicsApplications Testing (Bench & Pilot)Commercial Plant Location

Testing & Design Higgins Loop™ & Other Pilot Testing @ STS TampaDesign by STS (Loop) & Engineering Firm

Severn Trent ParticipationDirection of Process Development & System Design

Testing by Client, USF Students or SubcontractTechnical Support for Commercial SystemHLS Technology License & Production Fees

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Continuous I-X for Fertilizer ProductsSummary

Continuous I-X for Fertilizer ProductsSummary

HLS - Proven I-X Technology That Works5+ Decades of Experience in Specialized ProcessingReliable, Low Maintenance SystemFlexible Operation with PLC Controls & Qualify Monitoring

Produces Premium Fertilizers EconomicallyConvert Low Value Feedstocks into Value Added ProductsLow Capital Investment & Small System FootprintLiquid Fertilizer SolutionsDiversify FL Phosphate Plant Product Line

Favored Market Position Exclusive Rights to Proprietary ProcessAbility to Produce Customized Blends