• 2015 ~ present, Associate Professor, North Carolina State University
• 2011 ~ present, Adjunct Professor, Seoul National University
• 2016 Visiting Professor, KAIST
• 2009 ~ 2015, Assistant Professor, North Carolina State University
• 2007 ~ 2008, Postdoctoral Researcher, Bioenergy, National Renewable Energy Laboratory
• 2006 ~ 2007, Postdoctoral Researcher, Bioenergy, University of Tennessee at Knoxville
• 2006, Ph.D., Pulp and Paper, North Carolina State University
• 2001, M.S., Pulp and Paper, Seoul National University, Korea
• 1997, B.S., Forest Products, Seoul National University, Korea

Teaching

• PSE 355 Pulp and Paper Unit Processes I
• PSE 425 Bioenergy and Biomaterials Engineering
• WPS 760 Engineering Unit Operations for Biomass Conversion

Research Interests

His research is focused on the fundamental understanding of lignocellulosic biomass reactivity (changes in biomass chemistry/structure and their effects on conversion process) for both biochemical and thermochemical conversion processes into biofuels.

• Thermal pretreatment and its effect on fast pyrolysis. Thermal pretreatment of biomass such as torrefaction has a potential to be integrated with fast pyrolysis and gasification operation. His research is focused on the characterization of biomass chemistry/structure changes during thermal pretreatment and the evaluation of bio-oil quality when torrefied biomass is used.
• Cellulose crystalline structure and its allomorphs. Fundamental understanding of cellulose crystalline structure is critical for many applications such as paper, textiles, chemicals, and bioenergy. Recently we have applied new technology (sum-frequency-generation vibration spectroscopy) together with x-ray diffraction and solid-state NMR to elucidate its structure. SFG spectroscopy can selectively detect cellulose crystalline structure without interference from hemicellulose and lignin.
• Biomass post-treatment and enzymatic hydrolysis. Inefficient enzymatic hydrolysis of biomass is largely due to the recalcitrant nature of lignocellulosic biomass. This study focuses on identifying the physico-chemical properties of biomass responsible for low conversion efficiency and developing post-treatment operations to overcome recalcitrant issues.

Publications

• Impacts of feedstock properties on the process economics of fast-pyrolysis biorefineries (2018)
• Adsorption isotherm, kinetic modeling and mechanism of tetracycline on Pinus taeda-derived activated biochar (2018)
• Thermal depolymerization of biomass with emphasis on gasifier design and best method for catalytic hot gas conditioning (2018)
• Structural characterization of loblolly pine derived biochar by X-ray diffraction and electron energy loss spectroscopy (2018)
• Soluble lignin recovered from biorefinery pretreatment hydrolyzate characterized by lignin-carbohydrate complexes (2017)
• Effect of blending ratio of loblolly pine wood and bark on the properties of pyrolysis bio-oils (2017)
• Lignocentric analysis of a carbohydrate-producing lignocellulosic biorefinery process (2017)
• Pre-treatment of biomasses using magnetised sulfonic acid catalysts (2017)
• Engineering biorefinery residues from loblolly pine for supercapacitor applications (2017)
• Characterization of biofuel refinery byproduct via selective electrospray ionization tandem mass spectrometry (2017)

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