Steam explosion pretreatment and thermal degradation of cellulose fibers

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Influence of steam explosion pretreatment on the thermal degradation

of cellulose fibers

N. Jacquet a,b, N. Quievy c, C. Vanderghem a,b, J. Devaux c, C. Blecker b, M. Paquot a

a

_{Department of Industrial Biological Chemistry, Gembloux Agro-Bio Tech, Liège}

University

b

_{Departement of Food Technology, Gembloux Agro-Bio Tech, Liège University}

c

_{Université Catholique de Louvain, Unité de chimie et de physique des hauts}

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The aim of the present study was:

1) to compare the effect of different steam explosion pretreatments on the thermal degradation of a bleached cellulose where components like hemicelluloses and lignin

Background and Objectives

degradation of a bleached cellulose where components like hemicelluloses and lignin have already been removed by acid and alkalin treatments.

2) To identifie the concentration of degradation products (furfural and 5-hydroxymethylfurfural) in the liquor obtained after the pretreatment

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Materials and Methods

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Materials and Methods

Steam Explosion process

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60 70 80 90 100 w e ig h t o f th e s a m p le ( % )

Results

TGA of solid phase

Increase of carbonaceous

residues at the end of the pyrolysis (char) for the SE

0 10 20 30 40 50 60 0 100 200 300 400 500 600 Temperature (°C) w e ig h t o f th e s a m p le ( % )

C200 SE 10 bar SE 20 bar SE 30 bar SE 40 bar SE 50 bar

pyrolysis (char) for the SE

50 bar samples (14%)

compared to the others

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-1,5 -1 -0,5 0 0,5 0 100 200 300 400 500 600 % /° C C200 SE 10 bar SE 20 bar

Results

dTGA of solid phase

-3 -2,5 -2 -1,5 Temperature (°C) SE 30 bar

Temperature of the degradation peaks of cellulose decrease with the intensity of the pretreatement process

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HMF and 2F concentration in steam explosion liquors

Results

20,00 25,00 30,00 D e g ra d a tio n p ro d u c t / k g o f c e llu lo s e ( g ) HMF

Increase of HMF and 2F concentration in the liquor obtained at temperatures higher than 240°C

0,00 5,00 10,00 15,00 180 190 200 210 220 230 240 250 260 270 Temperature (°C) D e g ra d a tio n p ro d u c t / k g o f c e llu lo s e ( g ) HMF 2F

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Critical temperature : 240 - 250 °C

Important Thermal Degradation

Strong increasing of degradation product

Conclusions

Decrease of thermal stability of non-degraded steam explosion cellulose samples

Acknowledgements

: This study was financially supported by the Walloon Region

(TECHNOSE project number 716757; LIGNOFUEL project number 716721).

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