Hazelnut shell lignin

Extractionand

characterization

Ïu Azogue Coll

2nd PhD in Chemical Engineering

Summary

• Introduction about lignin

• Research objectives

• Results and conclusions about investigation

What is lignin?

• Vegetable material– Cellulose– Hemicellulose– LIGNIN

• Water removal from sugars to create aromatic structures

• Functions– Strength of wood

Where we can find?

• Lignin is an integral part of the secondary cell walls (not all cells)

• The most abundant organic material on earth after cellulose

• Most quantities of lignin– Hard parts of plants (Fruit shells, trunk)– Organic material from ground

Composition and structure

• Complex three-dimensional structure– Quantity increase through plant life– Intracellular growth

• Natural lignin composition and structure are unknown

• Factors which affect composition– Plant species– Part of plant

Composition and structure

• Three principal monomers– p-coumaryl alcohol– Coniferyl alcohol– Sinapyl alcohol

Natural and industrial sources

• Natural sources– All vegetable material

• Industrial sources– Pulping industry

Millions of tones are “produced” in paper industry

Production

• Paper production– Cellulose from vegetable material– Lignin is strongly linked to cellulose

• Industrial pulping allow cellulose and lignin separation– Pulp: To produce paper– Black liquor: Non-cellulose components

(Lignin)

Lignin: State of art

• Nowadays lignin is used as:– Binder– Dispersant– Emulsifer– Sequestrant

• Many researches are looking for new viable applications– EUROLIGNIN. European project to study

lignin properties, characterization, uses...

Research objectives

• Obtain optimal extraction conditions– Extractor agent– Temperature– Time

• Characterization– Functional groups

• Applications– Chelating agent

Extraction methods. Pulping

• Pulping process reproduced in laboratory:– Extractor agent (Soda, ethanol...)– Black liquor is separated by centrifugation

• Acid-precipitation of lignin from black liquor

• Lignin centrifugation and washing

Autoclave

Delignificated fiber

Black liquor

Fiber + Extractor agent solution

Centrifuge

Lignin precipitation with acid

Centrifuge

Liquid phase

Wet lignin

Dry lignin

Dryer

Characterization

• Principal polymer characteristic:– Conformation– Configuration– FUNCTIONAL GROUPS

• Methods:– Potentiometric– Spectroscopic

Potentiometric method

• Lignin titration– Obtaining of potentiometric curve– Observe equivalent point– Calculate functional group quantity

Spectroscopic method

• Different techniques– Fourier Transform Infrared– Ultraviolet– Nuclear magnetic resonance

• Analyzing the spectra diagrams:– Functional groups– Comparison between different lignins

Applications

• Chelating agent– Toxic metals complexationPb, Cr...– Metal micronutrients complexationNi, Mg, Fe, Zn...

• Complexation curves– Highest absorption

• Study optimal conditions– pH– Temperature

Results and conclusions

• Hazelnut lignin extraction depends mainly of soda concentration in present conditions

• Potentiometric titration require much experimentation time but can be a good characterization method

•That’s all!• Thank you very much for

your attention

• If you want to ask questions about presentation this is the moment (short moment I hope...)

Potentiometric curve

Functional groups

Carboxylic group

Phenolic hydroxyl group

Hydroxyl group

Lignin extraction

6% 9% 1215

30 min

60 min0,05,0

10,015,020,025,030,035,040,045,0

Lig

nin

e

xtr

ac

tio

n (

%)

NaOH concentration %

Extraction at 130ºC