Dr. Steven Crossley

EPSCoR Research Focus: 
Chemical Conversion
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Assistant Professor
School of Chemical, Biological and Materials Engineering
University of Oklahoma
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B.S. | Chemical Engineering | Oklahoma City University | 2004
Ph.D. | Chemical Engineering | University of Oklahoma | 2009
Research Interests: 

Deactivation Studies Associated with Upgrading of Pyrolysis Oils:

The conversion of lignocellulosic biomass to transportation fuels is one of the greatest challenges in catalysis today. A common technique employed is to produce an intermediate product known as pyrolysis oils through the fast pyrolysis of biomass. Pyrolysis oils contain a variety of compounds with a multitude of functional groups and a broad distribution of molecular weights. The optimal catalytic upgrading strategy varies with the functionality and molecular weight of a molecule. For example, it may be desirable to condense light aqueous phase species, such as acetic acid, while larger species such as lignin oligomers would benefit from the opposite strategy of depolymerization and deoxygenation. For this reason, a single upgrading strategy with the entire stream of pyrolysis oil is met with severe challenges. Pyrolysis oil cannot be separated through conventional means of distillation due to the thermal instability. Instead, pyrolysis oil must be separated through either staged upgrading, sequential condensation of the vapors, solubility of various oxygenates in different phases of varying polarity, or size exclusion.

While recent efforts have been made to develop improved fundamental understanding of how individual model compounds present in pyrolysis oils react across specific catalysts, the separation techniques described above are not sufficient to a single compound from the complex mixture known as pyrolysis oil. Instead, a best-case scenario is to provide a stream rich in a specific type of compound, for example rich in acid, furanics, or phenolics. In addition to these complexities, inorganic impurities and char particles present problems for deactivation. Dr. Crossley's project aims to investigate the fundamental role of these impurities present in a species rich on deactivation kinetics as well as the mechanism. This will be accomplished through several catalytic tests in flow reactors combined with detailed post run and in-situ catalyst characterization.

Graphic credit (above):  Center for Biomass Refining

Key Publications: 

Bold items indicate OK EPSCoR-supported research

Solid Nanoparticles that Catalyze Biofuel Upgrade Reactions at the Water/Oil Interface, Steven P. Crossley, Jimmy Faria, Min Shen, Daniel E. Resasco, Science, 327, 68-72, 2010.
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Catalytic Conversion of Anisole over HY and HZSM-5 Zeolites in the Presence of Different Hydrocarbon Mixtures, Teerawit Prasomsri, Anh T. To, Steven Crossley, Walter E. Alvarez, Daniel E. Resasco, Applied Catalysis B: Environmental, 106(1-2), 204-211, 2011.
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Direct Conversion of Triglycerides to Olefins and Paraffins over Noble Metal Supported Catalysts, Martina Chiappero, Phuong Thi Mai Do, Steven Crossley, Lance L. Lobban, Daniel E. Resasco, Fuel, 90 (3), 1155-1165, 2011.
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Molecular Engineering Approach in the Selection of Catalytic Strategies For Upgrading of Biofuels, Daniel E. Resasco, Steven P. Crossley, AIChE Journal, 55(5), 1082-1089, 2009.
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Etherification of 2-methylpentanal on Supported Palladium Catalysts, Trung Pham, Steven P. Crossley, Tawan Sooknoi, Lance L. Lobban, Daniel E. Resasco, Richard G. Mallinson, Applied Catalysis A: General, 379 (1-2), 135-140, 2010.
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Challenges and Opportunities for Catalysis Research in Biofuel Refining, Daniel E. Resasco, Steven Crossley, AIChE CEP, 105(5), 11, 2009.
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Activity Inhibition By Nitrogen Compounds in the Simultaneous Hydrogenation of Polyaromatic Compounds over NiMo/Al2O3 Catalyst in the Presence of Sulfur, Andrea R. Beltramone, Steven Crossley, Daniel E. Resasco, Tushar Choudhary, and Walter E. Alvarez. Catalysis Letters, 123, 181-185, 2008.
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A Novel Micropyrolyis Index (MPI) to Estimate Sooting Tendency of Fuels, Steven P. Crossley, Walter E. Alvarez, Daniel E. Resasco. Energy and Fuels, 22(4), 2455-2464, 2008. 
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Catalytic Strategies for Improving Specific Fuel Properties, Phuong Do, Steven Crossley, Malee Santikunaporn, and Daniel E. Resasco,  Catalysis (Special Periodical Reports) Royal Society of Chemistry, 20,  33-64, 2007. 
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Role of Bifunctional Catalysts on the Upgrading of Biomass Pyrolysis Oil Vapors
A presentation in the OK EPSCoR Biofuels Teleconference Series (Presented 2-15-2012)

Curriculum Vitae: