Near Infrared (NIR) Spectroscopy and Calibration in Biomass Characterisation Paul Geladi

Near Infrared (NIR) Spectroscopy and Calibration in

Biomass Characterisation

Paul Geladi

Paul Geladi

Head of Research NIRCEUnit of Biomass Technology and ChemistrySwedish University of Agricultural SciencesUmeåTechnobothniaVasa paul.geladi@btk.slu.se paul.geladi@syh.fi

Content

• What is biomass?• What is NIR spectroscopy?• Examples• What is calibration?• Advanced topics

Content

• What is biomass?• What is NIR spectroscopy?

• Examples

• What is calibration?

• Advanced topics

Biomass

Non-food

Food & feed

Bioenergy

Pulp and paper

ForestryBuilding materialsTextiles

Consumer products

Feed and safety

Where is biomass found?

• Biotechnology

• Natural products

• Bioenergy

What is special about biomass?

• O-H

• C-H

• N-H

• C=O

• different atom sizes = good

• IR+NIR energy = movements of bonds

O

H H

O

H H

O

H H

O

H H

Content

• What is biomass?

• What is NIR spectroscopy?• Examples

• What is calibration?

• Advanced topics

Near Infrared Spectra (NIR)

• 780-2500nm

• Suitable for all organic and bio materials

• Robust for industrial use

• Good penetration depth

• Many modes of measuring

• Powerful multivariate results

Cosmic Gamma Xray Ultraviolet Visible NIR Infrared Microwaves

Near Infrared Spectra

• Fast

• Simple sample preparation

• Nondestructive

• Online for process applications

• Need for calibration

• Opportunity for data analysis

Near Infrared Spectra?

• Visible

• Infrared

• Raman

• Polarization

Visible Near infrared Infrared Raman

400nm 780nm 2500nm 15000nm

Content

• What is biomass?• What is NIR spectroscopy?

• Examples• What is calibration?• Advanced topics• Plans for a network of excellence• Acknowledgement

EXAMPLES 1

• Organic synthesis

• Liquid

• Fiberoptic transflectance

• Over time

Fibers in Fibers out

Mirror

400 600 800 1000 1200 1400 1600 1800 2000 2200 24000

0.5

1

1.5

Wavelength

”Absorbance” H2O

visiblenear infrared

400 600 800 1000 1200 1400 1600 1800 2000 2200 24000

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

Wavelength

Absorbance Organic synthesis over time

CONCLUSION 1

• Possible to follow a reaction over time

• Identify reagents, products, intermediates

• Reaction kinetics

EXAMPLES 2

• Whole grain and flour

• Solid

• FT-NIR reflectance

• Genetic variation

1 1.5 2 2.5

x 10-4

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0.55

Wavelength

Pseudoabsorbance FLOUR

1 1.5 2 2.5

x 10-4

0.25

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0.75

Wavelength

Pseudoabsorbance WHOLE GRAINS

CONCLUSION 2

• Grain and flour different

• Genetic information

• Location information

• Accurate protein content

Where used?

• Food

• Feed

• Biofuel

• Fossil fuel

• Plastics

• Wood and pulp

• Environmental and waste

• Clinical and pharma

• In vivo

Rapid process monitoring for biofuels

• Canary reed grass

• Pellet / Briquette press

• The role of humidity

Biofuel energy unitBriquette machine

Mixing drum withwindow for measurement

Process NIR spectrometer

Reed canary grassBriquette

Predict = determine quality ahead

• Humidity for briquette quality

• Other parameters (e.g. ash content, energy, CO2) for energy production

Measure how?

• Location (how many? where?)

• How often?

• How detailed? Buckets? Single particles?

Content

• What is biomass?

• What is NIR spectroscopy?

• Examples

• What is calibration?• Advanced topics

Calibration

Concentration

Spectralproperty Model

y

Offset

Slope

Calibration

Xy

I

K

f

b

= +

y = Xb + f

Multivariate calibration

Why calibrate?

Spectrum Concentration

Spectrum -measured in 1 min-no sample preparation-on-line possible-noninvasive-nondestructive

Concentration-sample preparation-slow-expensive-waste chemicals-destructive

Methods of data analysis

• Multivariate calibration

• Classification

• Multivariate image analysis

• Multiway analysis

• Neural nets

• Genetic algorithms

Content

• What is biomass?

• What is NIR spectroscopy?

• Examples

• What is calibration?

• Advanced topics

High qualityinstrumentation

Simplified instrumentation

Experimentalinstrumentation

Complexity

Speed, Robustness

Instrumentation

Imaging / Spectroscopy

An image for each wavelength

A spectrum for each pixel

Table : Wavelength bands in some airborne / satellite imaging systems

Band/channelWavelength (nm)SPOT-XS LANDSAT-TM JERS-OPS AVIRIS

1 500-590 450-520 520-600 224 bands2 610-680 520-600 630-690 every 10nm3 790-890 630-690 760-860 390-2500 nm4 - 760-900 760-860*5 - 1550-1750 1600-17106 - 10400-12500 2010-21207 - 2080-2350 2130-22508 - - 2270-2400

* bands 3 and 4 are a stereo pair.SPOT-XS= (Système Probatoire d'Observation de la Terre) Image size 60x60 km; resolution 20x20 m. (Panchromatic = B/W resolution 10x10 m).LANDSAT-TM = (Thematic Mapper) Image size 185x172 km; resolution 30x30 mJERS-OPS = Japanese Earth ResourcesSatellite - Optical Sensor 75x75km; resolution 18.3x25.4 m. There is also 1.275 GHz radar.AVIRIS = (Airborne Visible/Infrared Imaging Spectrometer ) Typical 512x614 pixels and 20x20 m resolution.

Resolution

• Wavelength– reduction and selection

• Time – fast product streams– parallel measurements

• Space– 0-D bulk analysis– 1-D product streams– 2-D images, microscopy– 3-D tomography

What is newand exciting?

• Spatial resolution imaging in 2D, 3D• Fast streams in 1D• Polarisation etc.• Simplified instrumentation• Advanced data analysis• Database / search / control / presentation

Books to read

B. Osborne, T. Fearn & P. Hindle, Practical NIR Spectroscoy 2nd ed., Longman Scientific & Technical, Harlow, 1993, ISBN 0-582-09946-3

D. Burns & E. Ciurzak eds., Handbook of Near-Infrared Analysis 2nd ed., Marcel Dekker, New York, 200, ISBN 0-8247-0534-3

H. Siesler, Y. Ozaki, S. Kawata & H. Heise eds., Near-Infrared Spectroscopy, Wiley-VCH, Weinheim, 2002, ISBN 3-527-30149-6