Research Interests

Production of premium fuels and chemicals from biomass components

Hydrodeoxygenation of biomass-derived components

High-performance size exclusion chromatography of biomass-derived components

Areas of Expertise


Biomass composition and analysis

Biomass pretreatment

Biomass pyrolysis oil fractionation and analysis

Lignin chemistry

High-temperature and pressure lignin hydrotreating

Catalytic hydrodeoxygenation

Sugar and furan chemistries

Supercritical fluid extraction of biomass components

High-performance liquid and size exclusion chromatographies


Ph.D., Electrochemical Engineering, University of Southampton

B.S., Chemistry, University of Southampton

Professional Experience

Scientist V, Manager, NREL (2013–present)

Senior Scientist II, NREL (1998–2013)

Acting Branch Manager, NREL (1992–1993)

Senior Chemist, NREL (1989–1998)

Staff Electrochemical Engineer, NREL (1984–1989)

Postdoctoral Fellow, Solar Energy Research Institute (1982–1984)

Postdoctoral Fellow, University of California, Los Angeles (1980–1982)

Associations and Memberships

American Institute of Chemical Engineers

American Chemical Society—Cellulose and Renewables Division

Editorial board, Biotechnology for Biofuels journal

Featured Work

Investigation of the Role of Lignin in Biphasic Xylan Hydrolysis during Dilute Acid and Organosolv Pretreatment of Corn Stover, Green Chemistry (2015)

Chapter 19: A Route from Biomass to Hydrocarbons via Depolymerization and Decarboxylation of Microbially Produced Polyhydroxybutyrate, in Direct Microbial Conversion of Biomass to Advanced Biofuels (2015)

Effect of Mechanical Disruption on the Effectiveness of Three Reactors Used for Dilute Acid Pretreatment of Corn Stover Part 1: Chemical and Physical Substrate Analysis, Biotechnology for Biofuels (2014)

Investigation of Xylose Reversion Reactions That Can Occur during Dilute Acid Pretreatment, Energy & Fuels (2013)

Challenges for Assessing the Performance of Biomass Degrading Biocatalysts, Biomass Conversion (2012)

Effects of Alkaline or Liquid-Ammonia Treatment on Crystalline Cellulose: Changes in Crystalline Structure and Effects on Enzymatic Digestibility, Biotechnology for Biofuels (2011)

Glucose Reversion Reaction Kinetics, Journal of Agricultural and Food Chemistry (2010)

Cellulose Crystallinity Index: Measurement Techniques and Their Impact on Interpreting Cellulase Performance, Biotechnology for Biofuels (2010)

Chapter 14: Pretreatments for Enhanced Digestibility of Feedstocks, in Biomass Recalcitrance: Deconstructing the Plant Cell Wall for Bioenergy (2009)

Top Value-Added Chemicals from Biomass, DOE Report (2007)

Cellulase Digestibility of Pretreated Biomass is Limited by Cellulose Accessibility, Biotechnology and Bioengineering (2007)

Base-Catalyzed Depolymerization of Lignin: Separation of Monomers, Canadian Journal of Chemical Engineering (2007)

Biomass Recalcitrance: Engineering Plants and Enzymes for Biofuels Production, Science (2007)

Advance in the Thermal Depolymerization of Lignin via Base-Catalysis, Science in Thermal and Chemical Biomass Conversion (2005)

Organosolv Pretreatment for Enzymatic Hydrolysis of Poplars. 2. Catalyst Effects and the Combined Severity Parameter, Industrial & Engineering Chemistry Research (1990)