Investigation and modeling natural biodegradation system in soil; application for designing an...
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Transcript of Investigation and modeling natural biodegradation system in soil; application for designing an...
Investigation and modeling natural biodegradation system in soil;
application for designing an efficient biological pretreatment technology for
Biofuel production.
Mythreyi Chandoor, Deepak Singh and Shulin Chen
Bioprocessing and Bioproduct Engineering Laboratory, Department of Biological Systems
Engineering Washington State University .
Agenda
•Aim and importance of the project• Background – Hypothesis of the project• Experimental:
MicrobiologyChemical analysis of lignocellulose degradation in soilStructural analysis
• ModelingLignocellulose degradation in soilApplication
• Acknowledgements
Aim and importance of the project
•Demand for an Alternate fuel – The U.S. ethanol consumption is forecast to increase from 5.6 billion gallons last year to 13.5 billion gallons in 2012, (Thomson Reuters, 2009). • What are the challenges ? The greatest challenge lies in the deconstruction of lignin part of the biomass to release sugars.
Need for novel pretreatment technology !!
•Demand for an Alternate fuel – The U.S. ethanol consumption is forecast to increase from 5.6 billion gallons last year to 13.5 billion gallons in 2012, (Thomson Reuters, 2009). • What are the challenges ? The greatest challenge lies in the deconstruction of lignin part of the biomass to release sugars.
Need for novel pretreatment technology !!
Natural biodegradation system in soil
CelluloseHemicellulose Other complex
compounds
Degraded into smaller sub units.
Chemically modified
Humus
Organic acids
Polyurinoids
Metal Ions
Microcosm
Lignin
Microcosm
Amino acids
Background
Background
Delignification, repolymerization
Humus formation
Proteins
in soil
Lignocellulosic system in soil
Possible lignin mechanism in soil
Background
Humus
Other complex
compounds
Polyurinoids
Organic acidsAmino acids
Chemically modified/partially degraded Lignin
Lignin
Microcosm
• To understand the biodegradation of lignocellulose in soil
• To model the biodegradation of lignocellulose in soil
Design the pretreatment system
Aim of the projectBackground
Methodology
•SEM (Scanning Electron Microscopy)
• NMR(Solid State Nuclear Magnetic Resonance
Spectroscopy)
•1-D NMR (Nuclear Magnetic Resonance Spectroscopy )
• TG (Thermogravimetric Analysis )
• FTIR (Fourier Transform Infrared Spectroscopy)
• GC-MS (Gas Chromatography Mass Spectroscopy)
Experimental results
Scanning Electron Microscopy (SEM)
Aromatic carbons attached to methoxy groups in syringol unit
Amorphous and crystalline compounds attached to C4
C2,C3,C5 of cellulose
C4 of amorphous
cellulosePhenolmethoxyl of
coniferyl and sinapyl moities
4 weeks 8 weeks12 weeks16 weeks
Solid State NMR Analysis
Solid State NMR Analysis
•The amount of syringol and guaicol units of lignin have increased after 16 weeks
•The Oxidation of syringyl and guaicyl units of lignin will give rise to syringol and guaicol units.
Quantitatively , syringyl and guaicyl units have decreased where as the syringol and guaicol amounts have increased which shows that there is change in
the chemical nature of lignin structure
Solid State NMR Analysis
Batch samples for every four weeks
% C
once
ntr
atio
n o
f th
e to
tal c
omp
oun
d
Py-GC/MS Analysis
Py-GC/MS Analysis
•The Change in the lignin polymer is observed after the completion of 12 weeks.
•The increase in the lignin content is attributed to the kind of subunits taken into consideration ; Syringol ,guaicol , ethanone and others were considered which are formed as a result of oxidation or modification of lignin.
Cellulose and Hemicellulose are proportionately decreasing while the lignin concentration is stable
and increased after a period of 12 weeks
Py-GC/MS Analysis
δ 3.81
δ 3.81
Hα in β-structures
CONTROL
1H NMR analysis
16 week SAMPLE
•The signal at δ 3.81 ppm : methoxyl groups lower in sample.Indicates the enzymatic modification of the lignin molecules. •Signals in δ 4.39 ppm: Hγ in β-O-4 structures and β-5 structures and
•Signals in δ 5.49 ppm : Hα in β-5 structures respectively.
1H NMR analysis
•The low intensity of the protons in ß-O-4 units with biodegradation confirms the ß-O-4 linkage degradation during the biological degradation process.
•δ 6.93 ppm, δ 7.41 ppm, δ 7.53 ppm corresponding to aromatic protons (certain vinyl protons), aromatic protons in benzaldehyde units and vinyl protons on the carbon atoms adjacent to aromatic rings in cinnamaldehyde units and aromatic protons in benzaldehyde units respectively were in low intensity in the 16 week samples.
1H NMR analysis
TG Analysis
min0 5 10 15 200 250 300 350 40 45 50 55
Soil Sample S5 Soil sample S4,
After 20 weeks After 16 weeks After 12 weeks After 8 weeks After 4 weeks Sugars
Lignin
Modeling General Equation for the Soil Degradation system
[S]+[X]+O2 + H2O [P] + [S1] + CO2 +[X]Soil
pH
where in S = s1+ s2 + s3 .X = x1 +x2 +x3 .P = products ( glucose and other residual sugars ).S1 = modif ied lignin .
( s1 =cellulose , s2= hemicellulose, s3= lignin )
(Maximum microbial growth on the biomass respectively )
Water balance equation :
dm H2O /dt = dmbio H20/dt + dm H2O intake / dt - dmexhaust H2O/dt
mH20 = mass of H20 in soil mbio
H2O = mass of H2O evolution taking place as a result of the degradation dm H2O
intake = water intake via intake airdmexhaust H2O = Water outlet Via exhaust air here ,dmbio H20/dt = 0
Therefore , dm H2O /dt = dm H2O intake / dt - dmexhaust H2O/dt
(Input = output +accumulation - generation)
C02 Balance equation :
dm CO2 /dt = (dmCO2bio/dt- mCO2 dvexhaust /dt )/v
mCO2 = Mass of CO2 in soil dm CO2
bio = evolution of CO2 during Bioreaction V= free space in the soil dvexhaust /dt = flow of exhaust air
t = time dmCO2
bio/dt = negligible ;The change in the flow of the exhaust air is also negligible dmCO2/dt = Negligible Therefore not being considered .
Modeling
Microbial growth (X ) = x1+x2+x3
= max f temp * si / Ksi + si -
where in Si = s1/s2/s3 .dx/dt = x1
d(S1) / d(t) = -Vb1*S1*X1/(Ks1+S1) #Cellulose BalanceS1(0) = 0.71 # weight in gm/gm
d(S2) / d(t) = -Vb2*S2*X2/(Ks2+S2) #Hemicellulose BalanceS2(0) = 0.48 #
d(S3) / d(t) = -Vb3*S3*X3/(Ks3+S3) #Lignin BalanceS3(0) = 0.28 #
Modeling
We derived an relation using polymath which defines the degradation pattern in the soil system.
µ=µmax1*S1/(Ks1+S1)-∆1
t(0) = 0t(f) = 3360 µ2=µmax2*S2/(Ks2+S2)- ∆ 2 µ3=µmax3*S3/(KS3+S3)- ∆ 3
Considering the values as follows ;µmax1=0.08µmax2=0.05μmax3=0.03 ∆ 1=0.001∆ 2=0.001∆ 3=0.001
Modeling
Modeling
Time (in hours )
Init
ial S
ubst
rate
co n
cent
r ati
on in
gm
/ gm
Application of the model
•The model developed is a relation drawn between the total initial concentrations of the cellulose, hemicellulose and lignin , defined in a specific proportion at any point of time .
•Further ,the model would correlate the various factors involved parallel to the degradation rates of each component respectively.
•The model developed is a relation drawn between the total initial concentrations of the cellulose, hemicellulose and lignin , defined in a specific proportion at any point of time .
•Further ,the model would correlate the various factors involved parallel to the degradation rates of each component respectively.
Conclusion
Based on the different experiments conducted on the samples which were incubated for 4,8,12,16 and 20 weeks it has been observed that :
•The optimized conditions for lignin modification is obtained after a period of 16 weeks .
•These optimized conditions are in relation to various factors present in the soil system, with respect to the relative
proportion of each component .
Based on the different experiments conducted on the samples which were incubated for 4,8,12,16 and 20 weeks it has been observed that :
•The optimized conditions for lignin modification is obtained after a period of 16 weeks .
•These optimized conditions are in relation to various factors present in the soil system, with respect to the relative
proportion of each component .
Conclusion
The determination of the exact relation between these factors would be helpful in
developing a model which would predict the specific ratio of cellulose, hemicellulose and
lignin apart from other factors involved such as pH,temperature and other organic
compounds.
Thus providing a suitable mechanism for the pretreatment technology !!
The determination of the exact relation between these factors would be helpful in
developing a model which would predict the specific ratio of cellulose, hemicellulose and
lignin apart from other factors involved such as pH,temperature and other organic
compounds.
Thus providing a suitable mechanism for the pretreatment technology !!
I would like to thank
•Dr. Ann Kennedy USDA-ARS Soil Scientist/ Adj. Prof. Crop and Soil Sciences,WSU.
•Dr. Greg Helms, NMR Center Director ,WSU.•Dr. Manuel Garcia-Perez. Assistant Professor / Scientist. Biological Systems Engineering ,WSU.•Dr. Bill , Assistant manager ,NMR Center,WSU.
And my Advisor …•Dr. Shulin Chen, Professor/Scientist. Department of Biological Systems Engineering,WSU .
Acknowledgements
And
My Team …
Any Questions ?