Xuejun Pan, Ph.D.

Associate Professor: Bioenergy and Bioproducts Engineering

Primary Office
Agricultural Engineering Building
Room 229
460 Henry Mall
Madison, WI 53706
Tel: (608) 262-4951
Fax: (608) 262-1228
E-mail: xpan@wisc.edu

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

Lab Website: http://biorefining.bse.wisc.edu/

Program Affiliations

  • Biological Systems Engineering

Education and Certificates

  • Ph.D. Applied Bioscience, Hokkaido University, Japan, 1999.
  • Ph.D. Chemical Engineering, Tianjin University of Science and Technology, China, 1993.
  • M.Eng. Chemical Engineering, Tianjin University of Science and Technology, China, 1986.
  • B.Eng. Chemical Engineering, Tianjin University of Science and Technology, China, 1983.

Fields of Interest

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

  •  Pretreatment and fractionation of lignocellulosic biomass for bioconversion
  • Chemical and enzymatic saccharification of lignocellulose
  • Catalytic conversion of lignocellulose to drop-in hydrocarbon fuel
  • Value-added utilization of cellulose, lignin, hemicellulose and extractives


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


    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.

    Q. 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

  •  Alfred Toepfer Faculty Fellow Award (2011)
  • NSF Career Award (8/2009)
  • American Society of Agricultural and Biological Engineering
  • American Chemical Society
  • Editorial board member of Journal of Biobased Materials and Bioenergy (2007-present)
  • Editorial board member of International Journal of Agricultural and Biological Engineering (2008-present)

Expertise Summary

Major Active Research Projects

  • X.J. Pan, NSF: Fundamental understanding of HDA process: one-step conversion of lignocellulosic biomass to furan-based precursors for drop-in liquid fuel  (2012-2015, $336,901).

  • X.J. Pan, NSF: Fast saccharification of lignocellulosic biomass under mild conditions in the medium of concentrated lithium bromide (2012-2015, $298,686).

  • X.J. Pan, NSF CAREER Award, CAREER: Fundamental understanding of behaviors and impacts of cell wall lignin during bioconversion of lignocellulose to fuel ethanol (2009-2014, $450,000).

  • J. Ralph, X.J. Pan and S. Patterson, Stanford GCEP, Efficient biomass conversion: delineating the best lignin monomer-substitutes (2009-2012, $1,377,000).