Arni%20Saleh

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Activity Presentation

• Arni Saleh
• Ph.D. student, xx cycle

• e-mail arni_at_unige.it
• arnisaleh_at_hotmail.com

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Aromatic compounds from Sugarcane Bagasse
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Presentation outline

• Background
• Biomass Pretreatment
• Process for extract lignin materials
• Lignin extractions
• Study of lignin extractions

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Background

• Bagasse material
• Renewable resource, economics and environment
• What is lignin?

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BackgroundWhat is Bagasse?

• Bagasse material
• Cellulose 33-48
• Hemicellulose 19-43
• Lignin 6-32
• Renewable Resource, Economics and Environment
• Increasing importance is being given to biomass
  as a renewable and environment friendly resource,
  which has motivated a great number of economic
  utilization as starting materials for various
  bioproduction.

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Background What is lignin?

• Natural lignin composition and structure are
  unknown.
• It is a heterogeneous polymer.
• It is made up of three principal monomers.

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Biomass Pretreatment
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Biomass Pretreatment

• Bagasse was first dried in sunlight, then in oven
  at 105C, cut into small pieces and stored in
  desiccator at room temperature. The dried biomass
  of bagasse was ground using a laboratory mill and
  screened to prepare 40 mesh powder.

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Processes for extract lignin materials

• Hydrolysis method
• Alkaline sugarcane bagasse hydrolysis

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Extraction of lignin from sugarcane bagasse
Hydrolysis method Alkaline sugarcane bagasse
hydrolysis
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Lignin extraction
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Lignin extraction
Bgasse (g) alkaline (NaOH) treatment (M) of main components extracted of main components extracted of main components extracted of main components extracted
Bgasse (g) alkaline (NaOH) treatment (M) p-coumaric acid Ferulic acid Syringic acid Vanillin
0.5 79.61 16.21 1.10 3.08
1.0 76.36 17.58 1.49 4.57
1.0 2.0 74.01 19.03 1.81 5.14
3.0 75.78 18.49 1.69 4.05
4.0 76.10 18.78 1.79 3.34
0.5 76.83 15.44 3.19 4.53
1.0 67.40 18.90 3.97 9.72
2.0 2.0 69.04 19.26 3.37 8.33
3.0 67.27 21.12 3.95 7.65
4.0 78.91 15.80 2.45 2.85
0.5 83.41 14.96 0.82 0.80
1.0 82.13 16.04 0.97 0.86
3.0 2.0 79.98 17.31 1.34 1.37
3.0 80.59 17.33 1.50 0.59
4.0 78.79 18.36 1.82 1.04
0.5 76.04 19.10 1.79 3.07
1.0 73.79 20.59 2.38 3.24
5.0 2.0 67.00 24.40 3.31 5.28
3.0 71.68 21.10 2.87 4.35
4.0 71.49 20.23 3.18 5.10
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Study of lignin extractions

• Experimental Techniques
• The determination of pKa by Uv/Vis Spectroscopy
• Study of aggregation by Uv/Vis Spectroscopy

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Experimental Techniques
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Uv/Vis Spectroscopy
Incident light Io
transmitted light It
Beer-Lambert Law is A ?cl log10(Io/It)
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Results
The determination of pKa by Uv/Vis Spectroscopy

• A) p-Coumaric acid result data
• B) Ferulic acid result data
• C) Syringic acid result data
• D) Vanillin result data

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p-Coumaric acid result data
Absorbance spectra of p-Coumaric acid, in only
solvent distilled water, an environment not
resistant to the effect of pH change from 2to 7.
Changes of a solution pH cause changes in the
electrostatic interactions within the component
and the solvent system.
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p-Coumaric acid result data
The effect of pH between 2 and 5, in this range
pCA is reversible and the maximum value of
absorbance is about pH 3.5 at lmax(310). The
reversible points indicated the p-Coumaric acid
is pure.
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Ferulic acid result data
From the analysis of the plots Absorbance of pH
Titration Curves Ferulic acid at lmax(322) and at
lmax(346), the pKa1 and pKa2 values were obtained
4.72, 9.21 respectively.
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Syringic acid result data
From the analysis of pH titration curves at
lmax(270), and lmax(300) were obtained the pKa1
4.47 pKa2 9.34
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Vanillin result data
pH Titration Curves of Vanillin, at lmax(348),
pKa 7.25.
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Study of aggregation by Uv/Vis Spectroscopy

• p-Coumaric acid
• Other components are under investigations.

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Absorbance spectra of a series of concentrations
of p-Coumaric acid in ethanol

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• Conclusions

I am tested four aromatic compounds, p-Coumaric
acid, Ferulic acid, Syringic acid and Vanillin.
All they basically have phenyl group and the
first three also have the carboxylic acid
chromophore. The first three have tow pKa values
because they have carbonyl group (gtCO)
chromophore. The pKa value of a chemical compound
determines its solubility and stability.
In ethanol the p-Coumaric acid at high
concentration makes dimerisation.
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The four aromatic compounds
Compound Formula Mol. Wt (g/mol) Structure pKa
p-Coumaric acid C9H8O3 164.15 4.5, 9.35
Ferulic acid C10H10O4 194.18 4.7, 9.2
Syringic acid C9H10O5 198.17 4.5, 9.34
Vanillin C8H8O3 152.14 7.3
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Thats all! Thank you very much for your attention