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