Ryan West

~bio~

-contact-
ryanwest@wisc.edu
(608) 262-0327

-status-
5th year graduate student

-research area-
Aqueous Phase Processing, Solid Acid Catalysis, Supported Metal Catalysis, Renewable Fuels and Commodity Chemicals from Biomass

 -hometown-
Peshtigo, WI

-undergraduate-
University of Wisconsin, Madison,
Department of Chemistry

 -publications-

West, Ryan M.; Spangsberg Holm, Martin; Shunmugavel, Saravanamurugan; Xiong, Jianmin; Beversdorf, Zacharay; Taarning, Esben; Christensen, Claus Hviid. “Production of lactic Acid and its Derivatives from Biomass Derived Carbohydrates over Solid Acid Catalysts: A Kinetic and Deactivation Studay.” In Progress.

Kunkes, Edward L.; Simonetti, Dante A.; West, Ryan M.; Ruiz-Serrano, Juan Carlos; Gärtner, Christian, A.; Dumesic, James A. “Catalytic conversion of biomass to monofunctional hydrocarbons and targeted liquid fuel classes.” Science, doi:10.1126/science.1159210.

West, Ryan M.; Braden, Drew J.; Dumesic, James A. “Dehydration of Butanol to Butene over Solid Acid Catalysts in High Water Environments.” Submitted Journal of Catalysis, August, 2008.

West, Ryan M.; Liu, Zhen Y.; Peter, Maximilian; Dumesic, James A. “Carbon-carbon bond formation for biomass derived furfurals and ketones by aldol condensation in a biphasic system.” Journal of Molecular Catalysis A, doi:10.1016/j.molcata.2008.09.001.

West, Ryan M.; Liu, Zhen Y.; Peter, Maximilian; Dumesic, James A. “Liquid Alkanes with Targeted Molecular Weights from Biomass-Derived Carbohydrates.” ChemSusChem (2008), 1(5) 417-424.

Zhang, Zhengcheng; Lyons, Leslie J.; West, Ryan M.; Amine, Khalil; West, Robert.   “Synthesis and ionic conductivity of mixed substituted polysiloxanes with oligoethyleneoxy and cyclic carbonate substituents.” Silicon Chemistry (2007), 3(5), 259-266.

Zhang, Zhengcheng; Sherlock, David; West, Ryan M.; West, Robert; Amine, Khalil; Lyons, Leslie J. “Cross-Linked Network Polymer Electrolytes Based on a Polysiloxane Backbone with Oligo(oxyethylene) Side Chains: Synthesis and Conductivity. Macromolecules (2003), 36(24), 9176-9180. 

~research summary~

My research focuses on the conversion of biomass derived carbohydrates into liquid fuels and commodity chemicals.   Specifically, I have focused on developing catalysts, processes and systems for this conversion and have focused on developing fundamental understanding of these processes.  Carbohydrates contain high extents of oxygenated functional groups that must be selectively removed or modified to create desired products.  These oxygenated groups lead to high solubilities of carbohydrates in water, requiring aqueous-phase processing of these compounds to fuels and chemicals.
            A particularly useful reaction sequence for aqueous-phase processing is dehydration followed by hydrogenation, in which oxygenated hydrocarbons, such as sorbitol, are first dehydrated over solid acid sites followed by hydrogenation on metal sites to form alkyl species.  Sequential operation of aqueous-phase dehydration/hydrogenation (APDH) leads to the formation of straight-chain alkanes, such as butane, pentane and hexane.  To understand the first step in this process, reaction kinetics studies of dehydration reactions over various solid acids catalysts in the presence of liquid water, mixed liquid and gaseous water and diluted water vapor were performed.  Sec-butanol was chosen as the reactant for studies of aqueous-phase dehydration, because it readily undergoes intramolecular dehydration to form three butene products.  Under these high pressures of water, silica-alumina, niobium phosphate and niobic acid are found to be stable and active for the dehydration of butanol, with niobium phosphate showing superior activity and water stability for this process.
            At low flow rates of gas, increasing the gas flow rate causes the preferential vaporization of butanol, leading to a decrease in the butanol pressure in the reactor and a corresponding decrease in the rate of dehydration.  Above a critical gas flow rate, the liquid feed becomes completely volatilized in the reactor, and increasing the gas flow rate further leads to a decrease in the pressure of water and a corresponding increase in the rate of dehydration.  In the vapor-liquid equilibrium regime, kinetic models predict that most of the catalyst is covered with multiple layers of water, and dehydration takes place by reaction of hydrated-adsorbed butanol with a hydrated surface site.  In the vapor-only regime, models predicts that the fraction of vacant active sites increases with increasing gas flow rate, and dehydration takes place by reaction of adsorbed butanol with a vacant surface site.
            Using the water stable niobium phosphate catalyst from the sec-butanol studies, a highly effective APDH catalyst, Pt - niobium phosphate, was developed capable of efficiently producing an alkane effluent with targeted molecular weights, such as C8 – C15 for jet fuel applications.  Targeted alkanes can be produced directly from fructose by an integrated process involving the dehydration, aldol condensation, hydrogenation and finally dehydration/hydrogenation.   The first step in this process involves the bi-phasic dehydration of hexose, pentose or methyl pentose sugars to form furfural compounds.  These furfural compounds were next condensed with biomass derived ketones in a separate bi-phasic system to produce carbon chains of various lengths.  The length of the carbon chains can be targeted by careful selection of the reactants, ratios of reactants and operating conditions of this step.  Process modeling of this step allowed us to further understand and optimize this step for maximum yield of aldol adducts.  These aldol adducts were then hydrogenated and dehydrated/hydrogenated  to alkanes using the niobium phosphate catalyst.  By understanding and manipulating the conditions of the aldol condensation step, the alkane distribution can be directed towards either the C7-C9 or C12-C15 range.
            Changing the nature of the support and adding a modifying metal to Pt can produce vastly different effluents from similar feeds in aqueous based processing.  Using carbon as a support instead of solid acids and combining Re with Pt yields a mixture of oxygenated hydrocarbons with a specific composition.  In contrast, using a Pt acidic catalyst, as described above, produces mostly saturated alkanes. This mixture of oxygenated hydrocarbons includes ketones, alcohols, saturated pyrans, saturated furans and acids.  Using this mixture as a feedstock, commodity chemicals, long chain alkanes similar to jet and diesel fuels, and gasoline components can be efficiently produced via different processes.  Aromatization and dehydration/dimerization/cracking leads to common components found in gasoline such as aromatics, branched alkanes and alkenes.  These can be performed using the well known H-ZSM5 catalyst operated at different conditions.  The acids can be combined via a ketonization reaction to form long ketones using ceria derived catalyst.  Alternatively, the ketones can be condensed via an aldol condensation route to form conjugated ketones.  These ketones from both processes can then be dehydrated and hydrogenated to for long chain alkanes using processes previously outlined.
            Another approach for converting sugars into commodity chemicals involves dehydration and isomerization reactions in aqueous or alcoholic media.  The triose sugars dihydroxyacetone and glyceraldehyde can be effectively converted into lactic acid or its derivate methyl lactate using zeolite catalysts.  In this process the triose sugars are dehydrated to form pyruvic acid which is subsequently hydrated in water or formed into a methyl acetal in methanol and isomerized into lactic acid or methyl lactate.  The production of lactic acid, however was found to destroy the zeolite though dealumination and pore collapse.  Through characterization and modeling of the system, high yields and low deactivation can be achieved by using the proper choice of reacting parameters, namely low concentration of feed sugar in an alcoholic medium.

 -awards and associations-

-  Vilas Travel Fellowship, University of Wisconsin, Summer 2008
-  NSF PIRE Graduate Student Fellowship, Summer 2008
-  Roland A. Ragatz Teaching Assistant Award, University of Wisconsin, Fall 2006
-  NSF Honorable Mention, Graduate Research Fellowship, March, 2006

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