1

Portable Hydrocarbon Sensors for Oil Sands Applications

M.T. Taschuk1, Q. Wang1, S. Drake1, A. Ewanchuk2 , M. Gupta1, Y. Zhou1, D. Ha1,

M. Alostaz2, A. Ulrich2, D. Sego2, Y.Y. Tsui1

1. Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4

2. Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2W2

2010 International Oil Sands Tailings Conference, December 5th - 8th, Edmonton, Alberta, Canada

2

© Varian

© Paramount

Low-Cost PortableRapid MeasurementsLow Resolution & Specificity

High Cost UnportableLong TurnaroundHigh Resolution & Specificity

Concept Performance

Tradeoffs

6 ppm NA

3

Concept Low-cost, RapidScreening Tools

© Varian

© Paramount© Paramount

4

Outline

Device Physics Why light-emitting diodes (LED)? LED induced fluorescence (LEDIF) Optical Theory & Specifications

Device Performance Naphthenic Acids (NA) in Process-Affected (PA) water Hydrocarbon Detection

Instrument Outlook Summary

5

Why LEDs?Haitz’s Law

Similar to Moore’s Law

Power per LED doubles every 2.3 years

Cost per Lumen halves every 3 years

Impacts many optical technologies: communications lighting chemical sensors fluorescence

Source: Nature Photonics 1 (2007) pp. 25

6

Broad bandwidth signals

Highly sensitive: ppb LODs typical

Minimal sample preparation

Non-destructive

For LEDs: broad bandwidth degrades signals limits on excitation wavelengths more flexible output

LED Induced Fluorescence (LEDIF)Technique Characteristics

Hannes Grobe

ground state

excited states

excitationlight

emittedlight

7

PrototypeMeasurement Process

1. Ultraviolet LEDs emit light

UV LEDs

Collection Lens

SampleCuvette

Parabolic Mirror

Spectrometer

€

S = LTRdetectorΦ E target ,α excite,α emit( )

€

Φ E target ,α excite,α emit( ) =η

4πE target

α excite

α excite +α emit

1− e−L α excite +α emit( )[ ]

8

PrototypeMeasurement Process

1. Ultraviolet LEDs emit light

2. Parabolic mirror focuses on sample

UV LEDs

Collection Lens

SampleCuvette

Parabolic Mirror

Spectrometer

€

S = LTRdetectorΦ E target ,α excite,α emit( )

€

Φ E target ,α excite,α emit( ) =η

4πE target

α excite

α excite +α emit

1− e−L α excite +α emit( )[ ]

9

PrototypeMeasurement Process

1. Ultraviolet LEDs emit light

2. Parabolic mirror focuses on sample

3. Sample fluoresces

UV LEDs

Collection Lens

SampleCuvette

Parabolic Mirror

Spectrometer

€

S = LTRdetectorΦ E target ,α excite,α emit( )

€

Φ E target ,α excite,α emit( ) =η

4πE target

α excite

α excite +α emit

1− e−L α excite +α emit( )[ ]

10

PrototypeMeasurement Process

1. Ultraviolet LEDs emit light

2. Parabolic mirror focuses on sample

3. Sample fluoresces

4. Parabolic mirror captures emission

UV LEDs

Collection Lens

SampleCuvette

Parabolic Mirror

Spectrometer

€

S = LTRdetectorΦ E target ,α excite,α emit( )

€

Φ E target ,α excite,α emit( ) =η

4πE target

α excite

α excite +α emit

1− e−L α excite +α emit( )[ ]

11

PrototypeMeasurement Process

1. Ultraviolet LEDs emit light

2. Parabolic mirror focuses on sample

3. Sample fluoresces

4. Parabolic mirror captures emission

5. Collection lens couples to spectrometer

UV LEDs

Collection Lens

SampleCuvette

Parabolic Mirror

Spectrometer

€

S = LTRdetectorΦ E target ,α excite,α emit( )

€

Φ E target ,α excite,α emit( ) =η

4πE target

α excite

α excite +α emit

1− e−L α excite +α emit( )[ ]

12

Optics: Excitation: 265 nm – 340 nm Emission: 200 nm – 800 nm f/3 collection; f/4 spectrometer

Hardware Commercial, off the shelf components No moving parts

Rapid measurement: < 5 seconds Prototype Cost: $10k

PrototypeSpecifications

13

Outline

Device Physics Why light-emitting diodes (LED)? LED induced fluorescence (LEDIF) Optical Theory & Specifications

Device Performance Naphthenic Acids (NA) in Process-Affected (PA) water Hydrocarbon Detection

Instrument Outlook Summary

14

LEDIF of NAPrototype Responsivity

285 nm, Navg = 5, tg = 5 s NA detectable well below

10 mg L-1 in 25 seconds

Device performance expected to improve

Concentrations by FTIR

15

285 nm, 68 ppm NA, Navg = 5, tg = 5 s

LEDIF of NAUnfiltered Process-Affected Water

NA signature in unfiltered process-affected water

No sample preparation

25 second measurement

16

LEDIF of HydrocarbonsNaphthalene

265 nm, Navg = 1, tg = 5 s

LOD < 1 ppm

5 second measurement

Can trade speed for sensitivity

Fine spectral features broadened by LED bandwidth

17

LEDIF of HydrocarbonsSummary Table

Compound Limit of Detection Measurement Time

Naphthenic Acids < 5 ppm 25 s

Napthalene < 1 ppm 5 s

Phenanthrene < 1 ppm 5 s

Pyrene < 100 ppb 1 s

Diesel < 100 ppm 5 s

Gasoline < 10 ppm 5 s

Crude Oil < 1 ppm 5 s

18

LEDIF of HydrocarbonsDiesel in Soil

Diesel-saturated sand samples

Preliminary evidence suggests we can distinguish weathered diesel and diesel

Further work required to establish calibration curve for weathering

265 nm, Navg = 5, tg = 1 s (WD), tg = 2 s (D)

19

Outline

Device Physics Why light-emitting diodes (LED)? LED induced fluorescence (LEDIF) Optical Theory & Specifications

Device Performance Naphthenic Acids (NA) in Process-Affected (PA) water Hydrocarbon Detection

Instrument Outlook Summary

20

© Varian

© Paramount

Low-Cost PortableRapid MeasurementsLow Resolution & Specificity

High Cost UnportableLong TurnaroundHigh Resolution & Specificity

Concept Future Work

Today

2011

21

Instrumental OutlookRoom for Improvement

More LEDs: 2X

Smaller! Bigger!

Improved f/#: 10X

Improved Optics: 2X€

€

S = LTRdetectorΦ E target ,α excite,α emit( )

22

Summary

Field portable hydrocarbon sensor developed NA LOD < 5 mg L-1, NA detected in unfiltered PAW Other compounds successfully detected at ppm level Rapid measurements: 25 s for NA, 5 s for remainder≦ Prototype cost: $10k

Future Work Expect 10X to 100X improvement Handheld devices possible Inline, real-time monitors possible

6 ppm NA

23

Acknowledgements

24

Portable Hydrocarbon Sensors for Oil Sands Applications:

Additional Slides

M.T. Taschuk1, Q. Wang1, S. Drake1, A. Ewanchuk2 , M. Gupta1, Y. Zhou1, D. Ha1,

M. Alostaz2, A. Ulrich2, D. Sego2, Y.Y. Tsui1

1. Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2V4

2. Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada, T6G 2W2

2010 International Oil Sands Tailings Conference, December 5th - 8th, Edmonton, Alberta, Canada

25

Off-the-shelf LED ~ 5% of bench top power

Trade resolution for power

Why LEDs?Comparison with Benchtop Instruments

© Varian

26

Excellent agreement with Varian Eclipse data LED related signals removed from prototype signal Further work required to optimize signals

LEDIF of NAComparison with Benchtop Instrument

280 nm270 nm

27

Device PerformanceCharacteristic Spectra

265 nm excitation, 1000 ms acquisition, 5 averages, 1.8 nm smooth13.7 mg/L Napthanic Acid in Water

Good spectra observed

Significant scatter from LED at 265 nm and ~500 nm

Post processing can separate peaks

28

LEDIF of HydrocarbonsPyrene

LOD < 100 ppb

1 second measurement

265 nm, Navg = 1, tg = 1 s

29

LEDIF of HydrocarbonsPhenanthrene

265 nm, Navg = 1, tg = 5 s

LOD < 1 ppm

5 second measurement

Can trade speed for sensitivity

Fine spectral features broadened by LED bandwidth