catalytic hydro-cracking of pyrolysis oil derived from ligninrbi.gatech.edu › sites › default...
Post on 27-Jun-2020
3 Views
Preview:
TRANSCRIPT
Wei Mu, Prof. Yulin Deng
Institute of Paper Science and Technology
Georgia Institute of Technology
Catalytic hydrodeoxygenation of
pyrolysis oil derived from lignin
Date: Mar 12, 2014
Reference: [1] U.S. Energy Information Administration / Annual Energy Review 2009
[2] http://www.saabhistory.com/2007/06/
Definition: Energy which comes from natural resources such as sunlight, wind, rain, tides,
and geothermal heat, which are renewable (naturally replenished)
Renewable Energy & Biomass
1
Functions of lignin
• Conducting water in plant stems.
• Providing mechanical support and structure.
• Resisting attack by most microorganisms.
Lignins, by John Ralph, Gosta Brunow, Wout Boerjan, ENCYCLOPEDIA OF LIFE SCIENCES & 2007, John Wiley & Sons, Ltd. www.els.net 3
Chemical structure of lignin
Oxygen/Carbon ratio (mole)
0 1.00.5
Hydrogen/Carbon ratio (mole)
0 2.01.0
Structure and elemental composition of lignin
2
Compare with gasoline and diesel. is lignin and is carbohydrate.
Carbon Chain Length
5 2010 15
Lignin monomer here. Typically organosolv lignin has about 150 carbons/molecule.
Barth and Kleinert. 2008. Energy Fuels. 22:1371-1379.
Lignin
Degradation
Crude Oil
4
Approach
Overview of My Research
LigninDegradation to small fragments
Upgrading
Biofuel
Objective: Convert lignin, which is a waste biomass, into biofuel or biochemical.
5
• Approach: Thermochemical treatment followed by hydrodeoxygenation upgrading.
• Catalyst screen: use model compound for reaction mechanism study
• Challenge: product analysis. Lignin has very complex structure.
PyrolysisN2 flow
400-600 oC
Biomass
Pyrolysis:
- Thermochemical conversion
process
- Break down the biomass in
the absence of oxygen.Furnace
N2 flow
Condenser
Liquid N2
Quartz tube Sample boat
Heavy oil Light oil Solid
+ + +
Gas products
• CO and CO2 ( >50%)
• H2 (~25 mol%)1
• Aliphatics, HCHO,
CH3CHO, etc
Pyrolysis oil: Dark brown liquids which
are comprised of hundreds of highly
oxygenated organic compounds2
Mainly recognized as
char with high energy.
Pyrolysis of Lignin
6
Gasoline Gasoil/diesel Carbohydrate Lignin
Carbon chain length 5-10 12-20 [6-5]n [9-10]n
0 5 10 15 20 25 30 35
Number of carbons
Heavy Oil
Light Oil
Gasoline
Heavy oil: Molecule weight between 200 – 1200 Dalton.
Chemical Review 2010, 110
Composition of Pyrolysis Oil
7
Heavy oil
Catalytic Hydrogeoxygenation
Hydrogen gas
8
Advantage Disadvantage
CoMoS2 Low cost, not poisoned by sulfur
Low reactivity, poisoned by water
Noble Metal Very active, water resistance
High price, poisoned by sulfur
• Unlike petroleum oil, biomass oil is inherently low sulfur and contains water.
• Noble metal catalysts can be run under low temperature, leads to less coke.
Pressurized reactor
Catalyst Screening
Light oil
• Mainly water soluble monomers.
• Ignored by many researchers because of large amount of water in light oil (~40-80w/w%)
• Yield of light oil from pyrolysis is around 15-35%.
• Overall weight of organic compounds in light oil is still over 1/3 the weight of heavy oil.
Upgrading of Light Oil
Light oil
•Result• High carbon yield. Approximately 100%.
• Fully hydrogenated. No aromatic ring left in the products.
• Cyclohexanol is the main product from the light oil upgrading.
9
Upgrading of Heavy Oil
10
Hydrodeoxygenation
H2 pressure, withNoble metal Catalyst
Gasoline-range productsHeavy oil
Dimer to trimer
• 2-step HDO reaction is required due to the tar formation deactivated the catalyst.
Fresh Step 1 Step 2
• Tentative reaction path
• First report about complete upgrading lignin pyrolysis oil to total aliphatic components by hydrogenation
Upgrading of Heavy Oil
11
• Products in pyrolysis oil from lignin were analyzed.
• Catalytic reaction
• Reaction mechanism of different noble metal catalyst was proposed from model compounds study.
• Both major components from pyrolysis oil were upgraded into gasoline range. Light oil upgrading only needed one step HDO. Heavy oil upgrading required two step HDO due to the tar forming.
• Monomers were produced through pyrolysis and HDO upgrading. (GPC) Fully hydrogenation and intensively deoxygenated products was obtained. (NMR)
12
Conclusion
• Prof. Yulin Deng
• The whole Deng’s Group
• Institute of Paper Science and
Technology
• School of Chemical and
Biochemical Engineering
Acknowledgement
Q & A
top related