University of Wisconsin–Madison

Xuejun Pan

Professor: Bioenergy and Bioproducts Engineering

(608) 262-4951

229 Agricultural Engineering Building
460 Henry Mall
Madison, WI 53706

Lab Office
546 Enzyme Institute Building
1710 University Avenue
Madison, WI 53726

Xuejun Pan Headshot

Lab website:

Program Affiliations

  • Biological Systems Engineering

Education and Certificates

  • B.E. 1983 – Chemical Engineering, Tianjin University of Science and Technology, China
  • M.E. 1986 – Chemical Engineering, Tianjin University of Science and Technology, China
  • Ph.D. 1993 – Chemical Engineering, Tianjin University of Science and Technology, China
  • Ph.D. 1996 – Applied Bioscience, Hokkaido University, Japan

Fields of Interest

Dr. Pan’s research is focused on developing innovative biorefining processes for producing energy, fuels, chemicals, and materials from renewable resources (biomass). Some specific research interests of Dr. Pan are listed below.

  • Pretreatment and fractionation of lignocellulosic biomass for bioconversion to chemicals and fuels
  • Enzymatic and non-enzymatic saccharification of cellulose and lignocellulose
  • Catalytic conversion of lignocellulose to drop-in hydrocarbon fuel
  • Platform chemicals from biomass
  • Functional materials from cellulose, lignin, hemicellulose, and extractives


  • BSE364: Engineering Properties of Food and Biological Materials
  • BSE460: Biorefining – Energy and Products from Renewable Resources



  • Shuai, L. and X.J. Pan. Method for producing liquid hydrocarbon fuels directly from lignocellulosic biomass. US 9,487,712B2. Date of patent: Nov. 8, 2016.
  • X.J. Pan and L. Shuai. Saccharification of Lignocellulosic Biomass. US 9,187,790B2, Date of patent: Nov. 17, 2015.
  • G.S. Wang, X.J. Pan, J.Y. Zhu and R. Gleisner. Sulfite pretreatment for biorefining biomass. US 9,090,915B2, Date of patent: July 28, 2015.

Selected Peer-Reviewed Articles

  • Chen,  L.H., J.Z. Dou, Q.L. Ma, N. Li, R.C. Wu, H.Y. Bian, D.J. Yelle, T. Vuorinen, S.Y. Fu, X.J. Pan, J.Y. Zhu. Rapid and near-complete dissolution of wood lignin at ≤ 80°C by a recyclable acid hydrotrope. Science Advances. 2017, 3, e1701735.
  • Yoo, C.G., N. Li, M. Swannell, and X.J. Pan. Isomerization of Glucose to Fructose catalyzed by Lithium Bromide in Water. Green Chemistry, 2017, 19, 4402-4411
  • Zhang, H.D., N. Li, X.J. Pan, S.B. Wu, and J. Xie. Direct transformation of cellulose to gluconic acid in concentrated iron (III) chloride under mild conditions. ACS Sustainable Chemistry & Engineering. 2017, 5 (5), 4066-4072
  • Yoo, C.G., S.T. Zhang, and X.J. Pan. Effective conversion of biomass into bromomethylfurfural, furfural, and depolymerized lignin in lithium bromide molten salt hydrate of a biphasic system. RSC Advances. 2017, 7, 300-308.
  • Yang, X.H., N. Li, X.L. Lin, X.J. Pan, and Y.H. Zhou.   Selective cleavage of the aryl ether bonds in lignin for depolymerization by acidic lithium bromide molten salt hydrate under mild conditions. Journal of Agricultural Food and Chemistry, 2016, 44, 8379-8387.
  • Yang, Q. and X.J. Pan. Bifunctional porous polymers bearing boronic and sulfonic acids for hydrolysis of cellulose.   ACS Sustainable Chemistry and Engineering, 2016, 4, 4824-4830.
  • Li, N., X.J. Pan, and J. Alexander.    A facile and fast method for quantitating lignin in lignocellulosic biomass using acidic lithium bromide trihydrate (ALBTH).  Green Chemistry, 2016, 18, 5367-5376.
  • Yoo, C.G. and X.J. Pan. Pretreatment of lignocellulosic feedstocks. In: “Bioenergy: Principles and Applications”, Edited by Y.B. Li and S.K. Khanal, John Wiley & Sons, Inc., 2016, pp. 201-223. (ISBN: 9781118568316)
  • Yang, Q. and X.J. Pan. Synthesis and application of bifunctional porous polymers bearing chloride and sulfonic acid as cellulase-mimetic solid acids for cellulose hydrolysis. BioEnergy Research, 2016, 9, 578-586.
  • Yang, Q. and X.J. Pan. Correlation between lignin physicochemical properties and inhibition to enzymatic hydrolysis of cellulose. Biotechnology and Bioengineering, 2016, 113, 1213–1224.
  • Zhang, H.D., N. Li, X.J. Pan, S.B. Wu, and J. Xie. Oxidative conversion of glucose to gluconic acid by iron (III) chloride in water under mild conditions. Green Chemistry, 2016, 18, 2308-2312.
  • Yoo, C.G., H. Kim, F.C. Lu, A. Azarpira, X.J. Pan, K.K. Oh, J.S. Kim, J. Ralph, and T.H. Kim. Understanding the physicochemical characteristics and the improved enzymatic saccharification of corn stover pretreated with aqueous and gaseous ammonia. BioEnergy Research, 2016, 9 (1), 67-76.
  • Harde, S., Z.N. Wang, M. Horne, J.Y. Zhu, and X.J. Pan. Microbial lipid production from SPORL-pretreated Douglas fir by Mortierella isabellina. Fuel, 2016, 175, 64-74.
  • Pang, Z.Q., C.H. Dong, and X.J. Pan. Enhanced deconstruction and dissolution of lignocellulosic biomass in ionic liquid at higher water content by lithium chloride. Cellulose, 2016, 23, 323-338.
  • Yang, Q. and X.J. Pan. Fabrication and applications of biocompatible graphene oxide and graphene. In: “Handbook of Graphene Science”, Edited by Mahmood Aliofkhazraei, Nasar Ali, William I. Milne, Cengiz S. Ozkan, Stanislaw Mitura, Juana L. Gervasoni. CRC Press/Taylor & Francis, 2016, pp. 125-132. (ISBN: 9781466591271)
  • Zhang, C., R. Gleisner, C.J. Houtman, X. Pan, and J.Y. Zhu. Sulfite pretreatment to overcome the recalcitrance of lignocelluloses for bioconversion of woody biomass. In: “Biomass Fractionation Technologies for a Lignocellulosic Feedstock Based Biorefinery”, Edited by S. I. Mussatto, Elsevier, 2016, pp. 495-537. (ISBN: 9780128023235)
  • Yoo, C.G. and X.J. Pan. Fuel ethanol from lignocellulosic biomass. In: “Handbook of Clean Energy Systems”, Edited by J.Y. Yan, Vol. 1: Renewable Energy, p119-138, Wiley, 2015.
  • Noparat, P., P. Prasertsan, S. O-Thong, and X.J. Pan. Dilute acid pretreatment of oil palm trunk biomass at high temperature for enzymatic hydrolysis. Energy Procedia, 2015, 79, 924-929.
  • Grabber, J., N. Santoro, C.E. Foster, S. Elumalai, J. Ralph, and X.J. Pan. Incorporation of flavonoid derivatives or pentagalloyl glucose into lignin enhances cell wall saccharification following mild alkaline or acidic pretreatments. BioEnergy Research, 2015, 8, 1391-1400.
  • Zeng, J.J., C.G. Yoo, F. Wang, X.J. Pan, W. Vermerris, and Z.H. Tong. Biomimetic Fenton-catalyzed lignin depolymerization to high value aromatics and dicarboxylic acids. ChemSusChem, 2015, 8, 861-871.
  • Li, Z.Q., Z.H. Jiang, B.H. Fei, Z.Y. Cai, X.J. Pan. Comparison of bamboo green, timber and yellow in sulfite (SPORL), sulfuric acid and sodium hydroxide pretreatments for enzymatic saccharification. Bioresource Technology, 2014, 151, 91-99.
  • Lundberg, B., X.J. Pan, A. White, H. Chau, and A. Hotchkiss. Rheology and composition of processed citrus fiber Journal of Food Engineering. Journal of Food Engineering, 2014, 125, 97-104.
  • Cheng, J.L., S.-L. Leu, R. Gleisner, X.J. Pan, and J.Y. Zhu. High solids quasi-simultaneous enzymatic saccharification and fermentation of undetoxified whole slurry of SPORL pretreated Douglas fir forest residue. Cellulose Chemistry and Technology, 2014, 48, 849-854.
  • Pan, X.J. and J.N. Saddler. Effect of replacing polyol by organosolv and kraft lignin on the property and structure of rigid polyurethane foam. Biotechnology for Biofuels, 2013, 6, 12.
  • Zhang, D.S., Q. Yang, J.Y. Zhu, and X.J. Pan. Sulfite (SPORL) Pretreatment of Switchgrass for Enzymatic Saccharification. Bioresource Technology, 2013, 129, 127-134.
  • Li, Z.Q., Z.H. Jiang, B.H. Fei, X.J. Pan, Z.Y. Cai, X. Liu, and Y. Yu. Ethanosolv with NaOH pretreatment of moso bamboo for efficient enzymatic saccharification. BioResources, 2013, 8 (3), 4711-4721.
  • Shuai, L. and X.J. Pan. Hydrolysis of cellulose by cellulase-mimetic solid catalyst. Energy & Environmental Science, 2012, 5, 6889-6894.
  • Yang, Q. and X.J. Pan. Pretreatment of Agave americana stalk for enzymatic saccharification.Bioresource Technology, 2012, 126, 336-340.
  • Li, Z.Q., Q. Yang, Z.H. Jiang, B.H. Fei, Z.Y. Cai, and X.J. Pan. Comparative study of sulfite (SPORL), dilute acid and NaOH pretreatments of bamboo for enzymatic saccharification. Journal of Biobased Materials and Bioenergy, 2012, 6, 544-551.
  • Elumalai, S., Y. Tobimatsu, J.H. Grabber, X.J. Pan, and J. Ralph. Epigallocatechin Gallate Incorporation into Lignin Enhances the Alkaline Delignification and Enzymatic Saccharification of Cell Walls.  Biotechnology for Biofuels, 2012, 5, 59.
  • Shuai, L. and X.J. Pan. Hydrolysis of cellulose by cellulase-mimetic solid catalyst. Energy & Environmental Science, 2012, 5, 6889-6894.
  • Tobimatsu, Y., S. Elumalai, J.H. Grabber, C.L. Davidson, X.J. Pan and J. Ralph. Hydroxycinnamate conjugates as potential monolignol replacements: in vitro lignification and cell wall studies with rosmarinic acid. ChemSusChem, 2012, 5, 676-686.
  • Yang, Q., X.J. Pan, K. Clarke and K.C. Li. Covalent functionalization of graphene with polysaccharides. Industrial & Engineering Chemistry Research, 2012, 51, 310-317.
  • Li, Z., Z. Jiang, B. Fei, X.J. Pan, Z. Cai, X. Liu, and Y. Yu. Ethanol organosolv pretreatment of bamboo for efficient enzymatic saccharification. BioResources, 2012, 7, 3452-3462.
  • Yang, Q., X.J. Pan, F. Huang and K.C. Li. Functionalization of cellulose fiber with hyperbranched poly(3-methyl-3-oxetanemethanol) and poly(ε-caprolactone). Cellulose, 2011, 18, 1611-1621.
  • Zhu, J.Y., H. Liu, S. Verrill, V. Herian, X.J. Pan and D.L. Rockwood. On polydispersity of feedstock recalcitrance and its effects on pretreatment optimization for sugar production. BioEnergy Research, 2011, 4, 201-210.
  • Tian, S., W. Zhu, R. Gleisner, X.J. Pan and J.Y. Zhu. Comparisons of SPORL and dilute acid pretreatments for sugar and ethanol productions from aspen. Biotechnology Progress, 2011, 27, 419-427.
  • Kim, D.E. and X.J. Pan. Preliminary study on converting hybrid poplar to chemicals and high-quality lignin using organosolv process. Industrial & Engineering Chemistry Research, 2010, 49, 12156-12163.
  • Li, X.M. and X.J. Pan. Hydrogels based on hemicellulose and lignin from cellulose biorefinery: a mini-review. Journal of Biobaesd Materials and Bioenergy, 2010, 4, 289-297.
  • Luo, X., R. Gleisner, S. Tian, J. Negron, W. Zhu, E. Horn, X.J. Pan and J.Y. Zhu. Evaluation of mountain beetle-infested lodgepole pine for cellulosic ethanol production by SPORL pretreatment. Industrial & Engineering Chemistry Research, 2010, 49, 8258-8266.
  • Zhu, J.Y., X.J. Pan and R.S. Zalesny Jr. Pretreatment of Woody Biomass for Biofuel Production: Energy Efficiency, Technologies and Recalcitrance. Applied Microbiology and Biotechnology, 2010, 87, 847-857.
  • Yang, Q. and X.J. Pan. A facile approach for fabricating fluorescent cellulose. Journal of Applied Polymer Science, 2010, 117, 3639-3644.
  • Zhu, J.Y., W. Zhu, P. OBryan, B.S. Dien, S. Tian, R. Gleisner and X.J. Pan. Ethanol Production from SPORL-Pretreated Lodgepole Pine: Preliminary Evaluation of Mass Balance and Process Energy Efficiency. Applied Microbiology and Biotechnology, 2010, 86, 1355-1365.
  • Zhu, J.Y. and X.J. Pan. Woody biomass pretreatment for cellulosic ethanol production: technology and energy consumption evaluation. Bioresource Technology, 2010, 101, 4992-5002.
  • Yang, Q., X.J. Pan, F. Huang, and K.C. Li. Fabrication of high-concentration and stable aqueous suspensions of graphene nanosheets by noncovalent functionalization with natural polymers. Journal of Physical Chemistry-Part C, 2010, 114, 3811-3816.
  • Yang, Q. and X.J. Pan. Preparation and characterization of water-soluble single wall carbon nanotubes by hybridization with hydroxypropyl cellulose derivatives. Industrial & Engineering Chemistry Research, 2010, 49, 2747-2751.
  • Shuai, L., Q. Yang, J.Y. Zhu, F.C. Lu, P.J. Weimer, J. Ralph and X.J. Pan. Comparative study of SPORL and dilute acid pretreatments of spruce for cellulosic ethanol production. Bioresource Technology, 2010, 101, 3106-3114.
  • Zhu, W.Y., J.Y. Zhu, R. Gleisner and X.J. Pan. On energy consumption for size-reduction and enzymatic saccharification of softwood lodgepole pine. Bioresource Technology, 2010, 101, 2782-2792.
  • Tu, M., X.J. Pan and J. Saddler. Adsorption of cellulase on cellulolytic enzyme lignin from lodgepole pine. Journal of Agricultural and Food Chemistry, 2009, 57, 7771-7778.
  • Harmita, H., K.G. Karthikeyan and X.J. Pan. Copper and cadmium ions sorption onto kraft and organosolv lignins. Bioresource Technology, 2009, 100, 6183-6191.
  • Wang, G., X.J. Pan, J.Y. Zhu, R. Gleisner and D. Rockwood. Sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) for robust enzymatic saccharification of hardwoods. Biotechnology Progress, 2009, 25, 1086-1093.
  • Zhu, J.Y., X.J. Pan, G.S. Wang and R. Gleisner. Sulfite pretreatment (SPORL) for robust enzymatic saccharification of spruce and red pine. Bioresource Technology, 2009, 100, 2411-2418.
  • Zhu, J.Y., G.S. Wang, X.J. Pan and R. Gleisner. Specific surface to evaluate the efficiencies of milling and pretreatment of wood for enzymatic saccharification. Chemical Engineering Science, 2009, 64, 474-485.
  • Yang, L. Shuai and X.J. Pan. Synthesis of fluorescent chitosan and its application in noncovalent functionalization of carbon nanotubes. Biomacromolecules, 2008, 9, 3422-3426.
  • Yang, Q., L. Shuai, J.J. Zhou, F.C. Lu and X.J. Pan. Functionalization of multiwalled carbon nanotubes by pyrene-labeled hydroxypropyl cellulose. Journal of Physical Chemistry, Part B, 2008, 112, 12934-12939.
  • Pan, X.J., D. Xie, R. Yu and J. N. Saddler. The bioconversion of mountain pine beetle killed lodgepole pine to fuel ethanol using the organosolv process. Biotechnology and Bioengineering, 2008, 101, 39-48.
  • Pan, X.J. Role of functional groups in lignin inhibition of enzymatic hydrolysis of cellulose to glucose. Journal of Biobased Materials and Bioenergy, 2008, 2, 25-32.
  • Chandra, R.P., R. Bura, W. Mabee, A. Berlin, X.J. Pan and J.N. Saddler. Substrate Pretreatment: The Key to Effective Enzymatic Hydrolysis of Lignocellulosics? Advances in Biochemical Engineering/Biotechnology, 2007, 108, 67-93.
  • Pan, X.J., D. Xie, R. Yu, D. Lam and J. N. Saddler. Pretreatment of lodgepole pine killed by mountain pine beetle using organosolv ethanol process: fractionation and process optimization. Industrial & Engineering Chemistry Research, 2007, 46, 2609-2617.
  • Pan, X.J., D. Xie, K.-Y. Kang, S.-L. Yoon and J. N. Saddler. Effect of organosolv ethanol pretreatment variables on physical characteristics of hybrid poplar substrates. Applied Biochemistry and Biotechnology, 2007, 136-140, 367-378.
  • Pan, X.J., K. Ehara, J. Kadla, N. Gilkes and J. Saddler. Organosolv ethanol lignin from poplar as radical scavenger: relationship between lignin structure, extracting condition and antioxidant activity. Journal of Agricultural and Food Chemistry, 2006, 54, 5806-5813.
  • Pan, X.J., N. Gilkes and J. Saddler. Effect of acetyl groups on enzymatic hydrolysis of cellulosic substrates. Holzforschung, 2006, 60, 398-401.
  • Pan, X.J., N. Gilkes, J. Kadla, K. Pye, S. Saka, K. Ehara, D. Gregg, D. Xie, D. Lam and J. Saddler. Bioconversion of hybrid poplar to ethanol and co-products using an organosolv fractionation Process: Optimization of process yields. Biotechnology and Bioengineering, 2006, 94, 851-861.
  • Yu, F., Y.H. Liu, X.J. Pan, X.Y. Lin, C.M. Liu, P. Chen and R. Ruan. Liquefaction of corn stover and preparation of polyester from the liquefied polyol. Applied Biochemistry and Biotechnology, 2006, 129-132, 574-585.
  • Mabee, W.E., D.J. Gregg, C. Arato, A. Berlin, R. Bura, N. Gilkes, O. Mirochnik, X.J. Pan, E.K. Pye and J.N. Saddler. Updates on softwood-to-ethanol process development. Applied Biochemistry and Biotechnology, 2006, 129-132, 55-70.
  • Pan, X.J., C. Arato, N. Gilkes, D. J. Gregg, W. Mabee, E. K. Pye, Z. Xiao, X. Zhang and J. N. Saddler. Biorefining of softwoods using ethanol organosolv pulping – preliminary evaluation of process streams for manufacture of fuel-grade ethanol and co-products. Biotechnology and Bioengineering, 2005, 90 (4), 473-481.
  • Pan, X.J., D. Xie, N. Gilkes, D.J. Gregg and J.N. Saddler. Strategies to enhance the enzymatic hydrolysis of pretreated softwood with high residual lignin content. Applied Biochemistry and Biotechnology, 2005, 121-124, 1069-1079.
  • Pan. X.J. and Y. Sano. Fractionation of wheat straw by atmospheric acetic acid process. Bioresource Technology, 2005, 96 (11), 1256-1263.
  • Pan, X.J., X. Zhang, D.J. Gregg and J.N. Saddler. Enhanced enzymatic hydrolysis of steam-exploded Douglas fir by alkaline oxygen post-treatment. Applied Biochemistry and Biotechnology, 2004, 115, 1103-1114.
  • Li, Y., R. Ruan, P.L. Chen, Z. Liu, X.J. Pan, X. Lin, Y. Liu, C.K. Mok, T. Yang. Enzymatic hydrolysis of corn stover pretreated by combined dilute alkaline treatment and homogenization. Transactions of ASAE. 2004, 47 (3), 821-825.
  • Zhu, J.Y., X.-S. Chai, X.J. Pan, Q. Luo and J. Li. Quantification and reduction of organic sulfur compound formation in a commercial wood pulping process. Environ. Sci. Technol., 2002, 36, 2269-2272.
  • Pan, X.J. and Y. Sano. Characterization and comparison of milled wood, acetic acid and alkaline lignins from wheat straw. Holzforschung, 2000, 54 (1), 61-65.
  • Pan, X.J. and Y. Sano. Atmospheric acetic acid pulping of rice straw IV: Physico-chemical characterization of acetic acid lignins from rice straw and woods, Part 2. Chemical structures. Holzforschung, 1999, 53 (6), 590-596.
  • Pan, X.J. and Y. Sano. Atmospheric acetic acid pulping of rice straw IV: Physico-chemical characterization of acetic acid lignins from rice straw and woods, Part 1. Physical characteristics. Holzforschung, 1999, 53 (5), 511-518.
  • Pan, X.J. and Y. Sano. Acetic acid pulping of wheat straw under atmospheric pressure. Journal of Wood Science, 1999, 45 (4), 319-325.
  • Pan, X.J.; Y. Sano and T. Ito. Atmospheric acetic acid pulping of rice straw II: Behavior of ash and silica in rice straw during atmospheric acetic acid pulping and bleaching. Holzforschung, 1999, 53 (1), 49-55.

Selected Awards and Honors

  • Excellence in International Activities Award, College of Agricultural and Life Science, UW-Madison (2015)
  • Outstanding Faculty Award, Division of International Studies and International Student Services, UW-Madison (2014)
  • Elected Fellow, International Academy of Wood Science (2013)
  •  Alfred Toepfer Faculty Fellow Award (2011)
  • NSF Career Award (8/2009)
  • Associate Editor of BioEnergy Research (2013-present)

Selected Research Projects

  • X.J. Pan, NSF (CBET 1703519): Fabrication and fundamental understanding of cellulase-mimetic bifunctional solid acids for hydrolyzing cellulose.
  • X.J. Pan, NSF (CBET 1236562): Fundamental understanding of HDA process: one-step conversion of lignocellulosic biomass to furan-based precursors for drop-in liquid fuel.
  • X.J. Pan, NSF (CBET 1159561): Fast saccharification of lignocellulosic biomass under mild conditions in the medium of concentrated lithium bromide.
  • X.J. Pan, NSF CAREER Award (CBET 0847049): Fundamental understanding of behaviors and impacts of cell wall lignin during bioconversion of lignocellulose to fuel ethanol.