1. ANISOLE AND GUAIACOL HYDRODEOXYGENATION OVER MONOLITHIC Pt-Sn CATALYSTS
Miguel Ángel González Borja, Daniel E. Resasco
School of Chemical, Biological and Materials Engineering – University of Oklahoma
MOTIVATION & APPROACH
EXPERIMENTAL CONDITIONS
THEME : ENERGY
BIO-OIL MODEL
COMPOUNDS USED FOR THIS STUDY
Anisole
Guaiacol
LAB SCALE REACTION SYSTEM
OBJECTIVE
To produce stabilized bio-oil from biomass pyrolysis, that can be used as a fuel or as a feed for existing oil refining processes.
PROBLEM
Pyrolysis bio-oil is a complex mixture, which viscosity rapidly increases with time. This is a challenge for transportation and processing.
SOLUTION
To perform upgrading of biomass pyrolysis products in the vapor phase, before they are condensed into bio-oil. Thus a stabilized mixture can be obtained.
DIRECT VAPOR-PHASE UPGRADING OF BIOMASS PYROLYSIS PRODUCTS
Catalytic
Upgrading
DESIRED PRODUCTS
Aromatics: benzene, toluene, xylenes,
Condensation
Gas
Pyrolysis Reactor
High T
Reactants: Guaiacol / Anisole + Hydrogen (30:1 H2/Reactant molar ratio)
Temperature: 400°C Pressure: Atmospheric
Catalysts: Pt/Inconel, Sn/Inconel, Pt-Sn/Inconel, and Pt-Sn/CNF/Inconel Monoliths
STABILIZED
BIO-OIL
Char
Biomass
RESULTS III
Gas
CATALYST DEACTIVATION
ANISOLE
GUAIACOL
MONOLITHIC CATALYST
Reaction time
45 min
Reaction time
125 min
Reaction time
45 min
Reaction time
125 min
STEPS FOR THE SYNTHESIS OF MONOLITHIC CATALYST WITH SUITABLE PROPERTIES
Low Surface Area Inconel Monolith
Coating with carbon nanofibers (CNF)
Incorporation of Pt-Sn active metal
Decrease in benzene production
Cylindrical shape Inconel Monolith
Bare Inconel surface
<1 m2/g of CNF
Carbon nanofiber
Carbon nanofiber
with Pt-Sn particles
CNF coated surface
82 m2/g of CNF
Monolith Structure
Decrease in benzene production
LOW PRESSURE DROP
HIGH SURFACE AREA
CATALYTIC ACTIVITY
W/F = g cat/(g react./h). Represents size of the reactor
RESULTS I
RESULTS II
CONCLUSIONS
MONOMETALLIC VS. BIMETALLIC CATALYSTS
Pt-Sn ALLOY IN BIMETALLIC CATALYSTS
Bimetallic (Pt-Sn alloy) monoliths showed higher activity for the deoxygenation of guaiacol and anisole, when compared to monometallic monoliths.
Both Pt-Sn/Inconel and Pt-Sn/CNF/Inconel are able to fully deoxygenate guaiacol and anisole.
Coating with CNF greatly increased the surface area of the monoliths, allowing for a higher uptake during the active-phase incorporation.
Deactivation of the catalyst still needs to be improved; however, the Pt-Sn/CNF/Inconel monolith is a promising catalyst for the upgrading of pyrolysis bio-oil.
TEMPERATURE PROGRAMMED REDUCTION
Pt and Sn monometallic catalysts
Single reduction temperatures.
This technique is used to determine the reduction temperature of a species under the presence of hydrogen
Pt-Sn/Inconel catalysts
Single reduction temperature
One metallic phase: a Pt-Sn alloy.
Pt-Sn/CNF/Inconel activity >
Pt-Sn/Inconel activity
Pt-Sn/CNF/Inconel catalysts
Multiple reduction peaks.
Broad distribution of particle size
Presence of different alloy phases
Presence of unalloyed metal
HIGHER METAL DISPERSION
Bimetallic catalyst activity > Monometallic catalysts activity
Pt-Sn ALLOY FORMATION
ACKNOWLEDGEMENTS
REFERENCES
González-Borja, M.A., Resasco, D.E. Anisole and Guaiacol Hydrodeoxygenation over Monolithic Pt-Sn Catalysts. Energy Fuels. 2011, 25,
This work has been supported, in part, by the National Science Foundation (NSF EPSCoR Award EPS and MRINSF Grant ) and the Department of Energy (DE-FG36GO88064). Miguel Ángel González Borja thanks Dr. M. P. Ruiz, Dr. R. Jentoft, J. Brown, A. T. To, and M. Wulfers for their expert assistance in the characterization and synthesis of the monoliths.
“Commit to the Lord whatever you do, and your plans will succeed”