PowerPoint Presentation

THE DESALINATION OF SEAWATER THROUGH ELECTRODIALYSIS AND THERMAL DISTILLATIONMelissa GuardadoMing Suet KwanBrian Maynard

Pasadena City College

1

CALIFORNIA DROUGHTAs of January 14 2016: 42% of the state is in D4 (Exceptional Drought) status.

2

LAKE OROVILLE

CURRENT SOLUTIONS1. Water Conservation3. Water Reuse2. Storm water Capture4. Desalination

4

CARBON FOOTPRINT OF DESALINATION

High energy usage. Desalination requires a substantial amount of energy input to purify water for drinking purposes

High carbon emission. High energy usage correlates with a greater amount of emissions released. Carbon emissions are commonly associated with the disapproval of desalination systems.

Source: http://www.pacinst.org/reports/desalination_2013/energy/

5

PROJECT SCOPECONSTRUCT A UNIT THAT IS:Efficient in desalinationAble to treat Brackish water to fresh water

A realistic solution to California drought

6

PV-ED UNIT

7

Isabelle Kwan (IK) - Shall we delete this slide too?TREATMENT METHODSTHERMAL TECHNOLOGIESMultistage Flash DistillationMulti Effect DistillationMEMBRANE TECHNOLOGIESReverse OsmosisElectrodialysis

Thermal processes (MSF, MED, VC)Membrane processes (RO)Typical salt content of feedwater (ppm)30,000-100,0001,000-45,000Desalted water with low total dissolved solids concentrations (ppm)10.0-20.0100-550Thermal energy consumption (kWh/m^3)120Energy consumption (kWh/m^3)17-182.2-6.7Recovery Factor40-50%40-80%Capital costshighlowOperating costshighlowDesalted water cost ($/m3)0.9-1.40.50-0.70

8

DISTILLATION SET UP AT PCC

WHY ELECTRODIALYSIS?

Efficiency. It is efficient and effective in treating brackish water ranging from total dissolved solids (TDS) of 1000-5000 mg/L.

According to the USGS, in many regions where freshwater is lacking, there is an abundance of brackish groundwater.

An alternative solution to provide fresh water for barren, semi-arid, and remote regions.

Electro Dialysis Reversal (EDR) PlantBarcelona, Spain15,240 GPD

ELECTRODIALYSIS

ED stackElectrodesAnion and cation permeable membraneFlow pathDiluteConcentrateElectrode Rinse

11

PCC ELECTRODIALYSIS DEVICE

Initial test

Final test

PCC ED UNIT TEST

After 5 minutes of initial test:Minimum flow to flush systemConcentrate bucket was filling at higher speed Flush lines moved into the Dilute bucket (former concentration system) Content of flush bucket poured into concentration bucket

Over time: Dilute system increased in volumeConcentrate system decreased in volumeConclusion: Flow paths were mixing within the ED device

Initial PCC test

PCC vs. CPP ED UNITInitial CPP testFinal PCC test

Final CPP test

DATA COMPARISONDistillationEDSSalinity0.0%(~ pure water)0.6%(~ red sea)Energy used2.00 kWh/m31.43 kWh/m3Cost of energy$1.47/m3$1.05/m3

Distillation completely removed all salts while EDS gave a very low salinity in produced water. EDS uses 28.5% less energy than DistillationThus, EDS costs less.

Traditional desalinationEDSEnergy consumptionRequires more energyRequires less energyEnvironmental effectHigher emission of CO2Lower salinity discharged with 8-10times inlet flowLowering oxygen level by higher temperature of discharged brineAdditional chemicals:BiocideScale control chemicalsAntifoamLower CO2 emissionHigher salinity discharged with 3 times inlet flowUnaffected oxygen level due to unchanging temperature Additional chemicals:BiocideScale control chemicalsSustainability~40 years Depending on the construction materialsReplaceable membrane lifetime:~20 years Depending on membrane and pretreatment

SIGNIFICANCE OF DATA

ACKNOWLEDGEMENTS

Pasadena City CollegeDr. Veronica JaramilloRafik NazarpoorPhu NguyenCal Poly Pomona

Dr. Monica PalomoDr. Ali SharbatLucas TownsendKahao LimDr. Graciela MatrajitBrian RucciKristine SchroederSHINE