ANISOLE AND GUAIACOL HYDRODEOXYGENATION OVER MONOLITHIC Pt -Sn CATALYSTS

1. ANISOLE AND GUAIACOL HYDRODEOXYGENATION OVER MONOLITHIC Pt-SnCATALYSTS Miguel Ángel González Borja, Daniel E. Resasco School of Chemical, Biological and Materials Engineering – University of Oklahoma MOTIVATION & APPROACH EXPERIMENTAL CONDITIONS THEME : ENERGY 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, Gas Condensation 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 Incorporation of Pt-Snactive metal Coating with carbon nanofibers (CNF) 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 Snmonometallic 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, 4155-4162. This work has been supported, in part, by the National Science Foundation (NSF EPSCoR Award EPS0814361 and MRINSF Grant 0923247) 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”