Investigating 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 .
outline
•Aim and importance of the project• Background – Hypothesis of the project• Experimental:
MicrobiologyChemical analysis of lignocellulose degradation in soil.
• ModelingLignocellulose degradation in soilApplication
• Acknowledgements
Aim and importance of the project
•Demand for an Alternative 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 ? One of the challenges lies in the deconstruction of lignin part of the biomass to release sugars.
Need for novel pretreatment Technology !!
•Demand for an Alternative 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 ? One of the challenges lies in the deconstruction of lignin part of the biomass to release sugars.
Need for novel pretreatment Technology !!
Delignification, repolymerization
Humus formation
Proteins
in soil
Lignocellulosic system in soil
•To understand the biodegradation of lignocellulose in soil
• To model the biodegradation of lignocellulose in soil
Design the pretreatment system
Aim of the Project
Methodology
Scanning Electron Microscopy (SEM)
Scanning Electron Microscopy (SEM)
Aromatic carbons attached to methoxy groups in syringol unit
Guiacyl moities
C2,C3,C5 of cellulose
C4 of amorphous and crystalline
cellulosePhenolmethoxyl of
coniferyl and sinapyl moities
4 weeks 8 weeks
12 weeks16 weeks
Solid State NMR Analysis
Solid State NMR Analysis
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 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
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 Cellulose and hemicellulose
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)
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
Considering the values as follows ;µmax1=0.08 ∆ 1=0.001µmax2=0.05 ∆ 2=0.001μmax3=0.03 ∆ 3=0.001
We derived an relation using polymath which defines the degradation pattern in the soil system.
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
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 …
Thank you …
Any Questions ?