Biomass Depolymerization programs

Biomass Pretreatment & Chemical Synthesis of Transportation Fuels

This group is examining ionic liquids (ILs) and ionic liquid/co-solvents for their ability to dissolve the cellulosic components of lignocellulosic biomass. The mild conditions employed and the possibility of recovery and recycling of ionic liquids makes them attractive alternatives to dilute acid or hydrothermolysis pretreatments for hydrolyzing lignocellulose biomass. The use of ILs and biphasic water/IL systems as a reaction medium for converting sugars to fuel, rather than using water, is also being studied.

program Highlights

2014 Highlights

The aim of this program is to identify strategies for converting biomass to fuels, principally jet and diesel, and lubricants by means of purely chemical processes. The underlying premise is that chemically catalyzed processes are more rapid than those promoted by biochemical catalysts and, hence, can provide greater throughput per unit of reactor volume. As starting materials, we have chosen xylose and glucose, since these sugars can be obtained by either enzyme- or acid-catalyzed hydrolysis of hemicelluloses and cellulose, respectively. During 2014 we focused on following three steps: 1) Dehydration of glucose and xylose to produce hydroxymethylfurfural (HMF) and furfural (FUR); 2) Synthesis of jet and diesel from HMF, FUR, and 2,3-butanediol (BDO); and 3) Synthesis of lubricants from HMF and FUR. For each, the emphasis has been on identifying catalyst and processing conditions for obtaining high yields of the desired products.

2013 Highlights

This program focuses on identifying strategies for converting biomass to fuels and lubricants by means of purely chemical processes. Xylose and glucose are chosen as starting materials, since these sugars can be obtained by either enzyme- or acid-catalyzed hydrolysis of hemicelluloses and cellulose, respectively. During the past year efforts have focused on the dehydration of glucose and xylose to produce hydroxymethylfurfural (HMF) and furfural (FUR); the synthesis of jet and diesel from HMF, FUR, and 2,3-butanediol (BDO); and the synthesis of lubricants from HMF and FUR. High yields of FUR and HMF have been obtained by acid-catalyzed dehydration of xylose and glucose, respectively, in concentrated salt solutions with concurrent extraction into an organic phase. The hydrogenation of FUR and HMF over Pt/C can produce 2-pentanone and 2-hexanone in high yields.

2012 Highlights

Our primary goal is to evaluate options for pretreatment and hydrolysis of biomass and development of strategies for converting biomass-derived sugars to diesel. In 2012, a strategy was developed for the pretreatment of Miscanthus x giganteus with low concentration of base and hydrogen peroxide in order to achieve a high level of delignification. The cellulose and hemicelluloses released by this pretreatment is enzymatic hydrolysis much more readily than biomass pretreated by dilute acid. Strategies were explored for the acid-catalyzed dehydration of glucose and xylose with concurrent removal of hydroxymethyl furfural and furfural via either solvent extraction or membrane separation.


The synthesis of diesel fuels was investigated via two routes. The first is by the etherification of furfural alcohol or hydroxymethyl furfural with ethanol or butanol. High yields of either could be achieved. The second approach involves the furanylation of different furanic products to form C12-C15 compounds. Both the products of etherification and furnylation can be hydrogenated to produce pure alkanes. Additional coupling strategies are being explored to produce products in the diesel range. One attractive option involves aldol condensation of butylmethyl furan with furfural. The condensation of furanic to form C30-C45 products is also currently under investigation with the aim of developing precursors to other products.

2011 Highlights

The Bell group investigated factors influencing breakdown of cellulose and hemicellulose and defined the chemical characteristics of the reactions and reaction products. They were then able to increase the conversion of hemicellulose and xylose from Miscanthus from 69 to 90 percent with a concomitant increase in selectivity for monosaccharides. They also determined that, at least for Miscanthus, the presence of lignin does not affect yields, potentially eliminating the need for delignification and reducing costs. Co-Principal Investigator John Prausnitz directed efforts to establish a process for recovery and recycling of glucose from ILs, thus increasing yield. Using minerals known as zeolites, they removed 45 percent of the retained glucose, all of which could be recovered.

2010 Highlights

A strategy was developed for obtaining high yields of glucose and xylose from Miscanthus x giganteus dissolved in ionic liquid. Using this method, we observed minimum co-production of furanics and humins. Furthermore, we investigated catalytic strategies for selective dehydration of glucose to hydroxymethyl fufural and xylose to fufural. In addition, catalysts were identified for the synthesis of mono- and difuranyl ethers, compounds suitable for blending into diesel. Lastly, we explored strategies for extracting glucose and xylose from ionic liquids by preferential solvation and adsorption.



Published in 2014

Selective Hydrogenation of Furan-Containing Condensation Products as a Novel Source of Biomass-Derived Diesel Additives, Madhesan Balakrishnan, Eric R Sacia, Alexis T. Bell, ChemSusChem 7(10), 2796-8000, doi: 10.1002/cssc.201402764, October 2014.


Biomass Conversion to Diesel via the Etherification of Furanyl Alcohols Catalyzed by Amberlyst-15, Eric Sacia, Balakrishnan Madhesan, and Alexis T. Bell, Journal of Catalysis, V. 313, pp. 70-79, May 2014.


Syntheses of Biodiesel Precursors: Sulfonic Acid Catalysts for Condensation of Biomass-Derived Platform Molecules, Madhesan Balakrishnan, Eric R. Sacia, Alexis T. Bell, ChemSusChem, V. 7, pp. 1078-1085, March 5, 2014. 


Published in 2013

Preferential Interactions between Lithium Chloride and Glucan Chains in N,N-Dimethylacetamide Drive Cellulose Dissolution, A. S. Gross, A. T. Bell, J. W. Chu, Journal of Physical Chemistry B, 117(12), pp. 3280-3286, doi:10.1021/Jp311770u, March 28, 2013.


Pretreatment of Miscanthus X Giganteus Using Aqueous Ammonia with Hydrogen Perovide to Increase Enzymatic Hydrolysis to Sugars, Guangren Yu, Waheed Afzal, Fuxin Yang, Sasisanker Padmanabhan, Zhongguo Liu, Hongxue Xie, Mahmoud Abdel Shafy, Alexis T. Bell, J. M. Prausnitz, Journal of Chemical Technology and Biotechnology, doi: 10.1002/jctb.4172, August 14, 2013.


Two-Step Delignification of Miscanthus to Enhance Enzymatic Hydrolysis: Aqueous Ammonia Followed by Sodium Hydroxide and Oxidants, Zhongguo Liu, Sasisanker Padmanabhan, Kun Cheng, Philippe Schwyter, Markus Pauly, Alexis Bell, John M. Prausnitz, Energy and Fuels 28 (1), pp. 542-548, doi: 10.1021/ef401317z, October 9, 2013.


Aqueous-Ammonia Delignification of Miscanthus Followed by Enzymatic Hydrolysis to Sugars, Zhongguo Liu, Sasisanker Padmanabhan, Kun Chen, Phillipe Schwyter, Markus Pauly, Alexis T. Bell, John M. Prauisnitz, Bioresource Technology 135, pp. 23-29 (2013).

Published in 2012

Etherification and Reductive Etherification of 5-(hydroxymethyl) Furfural: 5-(alkoxymethyl) Furfurals and 2, 5-bis (alkoxymethyl) Furans as Potential Biodiesel Candidates, Madhesan Balakrishnan, Eric Sacia, Alexis T. Bell, Green Chemistry, doi: 10.1039/C2GC35102A, March 19, 2012.


Inert-Gas-Stripping Method for Measuring Solubilities of Sparingly Soluble Gases in Liquids; Solubilities of Some Gases in Protic Ionic Liquid 1-Butyl, 3-Hydrogen-Imidazolium Acetate, Waheed Afzal, Brian Yoo, John H. Prausnitz, Industrial and Engineering Chemistry Research, 51(11), pp. 4433-4439, doi: 10.1021/ie20228-y, March 21, 2012.

Published in 2011

Determination on Crystallinity of Ionic Liquids Pretreated Biomass, Hong Xue Xie, John Prausnitz, Xiu Ling Wu, Advanced Materials Research, Vols. 393-395, doi:10-4028/, pp. 668-671, November 22, 2011


Solubilities of Some Organic Solutes in 1-Ethyl-3-Methylimidazolium Acetate; Chromatographic Measurement and Predictions from COSMO-RS, Jan-Georg Rosenboom, Waheed Afzal, John Prausnitz, Journal of Chemical Thermodynamics, doi: 10.1016/j.jct.2011.11.005, November 15, 2011.


Delignification of Miscanthus by Extraction, Sasisanker Padmanabhan, Edmond Zaia, Katherine Wu, Harvey Blanch, Douglas Clark, Alexis Bell, John Prausnitz, Separation Science and Technology, doi:10.1080/01496395.2011.629639, November 4, 2011.


A Study of Acid-Catalyzed Hydrolysis of Cellulose Dissolved in Ionic Liquids and the Factors Influencing the Dehydration of Glucose and the Formation of Humins, Sean Dee, Alex Bell, Chemistry and Sustainability Energy and Materials, doi: 10.1002/cssc.201000426, August 2, 2011.


Recovery of Glucose from an Aqueous Ionic Liquid by Adsorption onto a Zeolite-Based Solid, Maria Francisco, Anton Mlinar, Brian Yoo, Alexis Bell, John Prausnitz, Chemical Engineering Journal, doi:10.1016/j.cej.2011.05.087, May 31, 2011.


Effects of Reaction Conditions on the Acid-Catalyzed Hydrolysis of Miscanthus Dissolved in an Ionic Liquid, Sean Dee, Alexis Bell, Green Chemistry, doi:10.1039/CIGC15317J, May 27, 2011.


Viscosities of Acetate or Chloride-Based Ionic Liquids and Some of Their Mixtures with Water or Other Common Solvents, Sebastian Fendt, Sasisanker Padmanabhan, Harvey Blanch, John Prausnitz, Journal of Chemical and Engineering Data, 56(1), pp. 31-34, doi: 10.1021/je1007235, January 2011.


Solubility and Rate of Dissolution for Miscanthus in Hydrophylic Ionic Liquids, Sasisanker Padmanabhan, Michael Kim, Harvey Blanch, John Prausnitz, Fluid Phase Equilibria, doi: 10.1016/j.fluid.2011.06.034, July 5, 2011

Published in 2010

Improved United-Atom Force Field for 1-Alkyl-methylimidazolium Chloride , Zhiping Liu, Ting Chen, Alexis Bell, Berend Smit, Journal of Physical Chemistry, 114(13): pp. 4572-4582, July 26, 2010. 


Fluid-Phase Equilibria in Binary Systems Containing an Ionic Liquid, Application of the Percus-Yevick-van der Waals Equation of State, Qin Xin, Geoffrey Poon, John Prausnitz, Journal of Supercritical Fluids, 55(2), pp. 817-824, DOI: 10.1016/j.supflu.2010.09.043, December 2010.  


Viscosities of the Mixtures of 1-Ethyl-3-Methylimidazolium Chloride with Water, Acetonitrile and Glucose: A Molecular Dynamics Simulation and Experimental Study, Ting Chen, Mandan Chidambaram, Zhiping Liu, Berend Smit, Alexis Bell, Journal of Physical Chemistry, 114(17): pp. 5790-5794, April 13, 2010.

A Two-Step Approach for the Catalytic Conversion of Glucose to 2,5-dimethylfuran in Ionic Liquids, Mandan Chidambaram, Alexis T. Bell, Green Chemistry, 12: pp. 1253-1262, May 28, 2010.    

Published in 2009

Are Pressure Fluctuation-Based Equilibrium Methods Really Worse Than Nonequilibrium Methods for Calculating Viscosities?, Ting Chen, Berend Smit, Alexis Bell, Journal of Chemical Physics, 131, Dec. 30, 2009.



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